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capebus: Add nixie cape support #5

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capebus: Add nixie cape support #5

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Initial capebus support for Nixie cape prototype that only exists on a breadboard.

Added nixie capebus PWM, leds, and spi-vfd definitions to am355x-bone-common

Signed-off-by: Matt Ranostay <mranostay@gmail.com>
Supported added for SPI VFD shift register device for nixie cape

Signed-off-by: Matt Ranostay <mranostay@gmail.com>
Add support for nixie cape breadboard prototype.

Signed-off-by: Matt Ranostay <mranostay@gmail.com>
Added SPI VFD and Nixie cape entrys in Kconfig and Makefile

Signed-off-by: Matt Ranostay <mranostay@gmail.com>
Add SPI VFD device to capebus pdevs for generic lookup.

Signed-off-by: Matt Ranostay <mranostay@gmail.com>
When updating vfd_display cancel old delayed workqueue and
trigger new event.

Signed-off-by: Matt Ranostay <mranostay@gmail.com>
cancel_delayed_work to store function and not update_vfd function

Signed-off-by: Matt Ranostay <mranostay@gmail.com>
@mranostay mranostay closed this Nov 25, 2012
koenkooi pushed a commit that referenced this pull request Dec 6, 2012
A rescue thread exiting TASK_INTERRUPTIBLE can lead to a task scheduling
off, never to be seen again.  In the case where this occurred, an exiting
thread hit reiserfs homebrew conditional resched while holding a mutex,
bringing the box to its knees.

PID: 18105  TASK: ffff8807fd412180  CPU: 5   COMMAND: "kdmflush"
 #0 [ffff8808157e7670] schedule at ffffffff8143f489
 #1 [ffff8808157e77b8] reiserfs_get_block at ffffffffa038ab2d [reiserfs]
 #2 [ffff8808157e79a8] __block_write_begin at ffffffff8117fb14
 #3 [ffff8808157e7a98] reiserfs_write_begin at ffffffffa0388695 [reiserfs]
 #4 [ffff8808157e7ad8] generic_perform_write at ffffffff810ee9e2
 #5 [ffff8808157e7b58] generic_file_buffered_write at ffffffff810eeb41
 #6 [ffff8808157e7ba8] __generic_file_aio_write at ffffffff810f1a3a
 #7 [ffff8808157e7c58] generic_file_aio_write at ffffffff810f1c88
 #8 [ffff8808157e7cc8] do_sync_write at ffffffff8114f850
 #9 [ffff8808157e7dd8] do_acct_process at ffffffff810a268f
    [exception RIP: kernel_thread_helper]
    RIP: ffffffff8144a5c0  RSP: ffff8808157e7f58  RFLAGS: 00000202
    RAX: 0000000000000000  RBX: 0000000000000000  RCX: 0000000000000000
    RDX: 0000000000000000  RSI: ffffffff8107af60  RDI: ffff8803ee491d18
    RBP: 0000000000000000   R8: 0000000000000000   R9: 0000000000000000
    R10: 0000000000000000  R11: 0000000000000000  R12: 0000000000000000
    R13: 0000000000000000  R14: 0000000000000000  R15: 0000000000000000
    ORIG_RAX: ffffffffffffffff  CS: 0010  SS: 0018

Signed-off-by: Mike Galbraith <mgalbraith@suse.de>
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: stable@vger.kernel.org
koenkooi pushed a commit that referenced this pull request Jan 9, 2013
All boards, except Amstrad E3, mark USB config with __initdata.

As a result, when you compile USB into modules, they will try to refer
already released platform data and the behaviour is undefined. For example
on Nokia 770, I get the following kernel panic when modprobing ohci-hcd:

[    3.462158] Unable to handle kernel paging request at virtual address e7fddef0
[    3.477050] pgd = c3434000
[    3.487365] [e7fddef0] *pgd=00000000
[    3.498535] Internal error: Oops: 80000005 [#1] ARM
[    3.510955] Modules linked in: ohci_hcd(+)
[    3.522705] CPU: 0    Not tainted  (3.7.0-770_tiny+ #5)
[    3.535552] PC is at 0xe7fddef0
[    3.546508] LR is at ohci_omap_init+0x5c/0x144 [ohci_hcd]
[    3.560272] pc : [<e7fddef0>]    lr : [<bf003140>]    psr: a0000013
[    3.560272] sp : c344bdb0  ip : c344bce0  fp : c344bdcc
[    3.589782] r10: 00000001  r9 : 00000000  r8 : 00000000
[    3.604553] r7 : 00000026  r6 : 000000de  r5 : c0227300  r4 : c342d620
[    3.621032] r3 : e7fddef0  r2 : c048b880  r1 : 00000000  r0 : 0000000a
[    3.637786] Flags: NzCv  IRQs on  FIQs on  Mode SVC_32  ISA ARM  Segment user
[    3.655822] Control: 0005317f  Table: 13434000  DAC: 00000015
[    3.672790] Process modprobe (pid: 425, stack limit = 0xc344a1b8)
[    3.690643] Stack: (0xc344bdb0 to 0xc344c000)
[    3.707031] bda0:                                     bf0030e4 c342d620 00000000 c049e62c
[    3.727905] bdc0: c344be04 c344bdd0 c0150ff0 bf0030f4 bf001b88 00000000 c048a4ac c345b020
[    3.748870] bde0: c342d620 00000000 c048a468 bf003968 00000001 bf006000 c344be34 c344be08
[    3.769836] be00: bf001bf0 c0150e48 00000000 c344be18 c00b9bfc c048a478 c048a4ac bf0037f8
[    3.790985] be20: c012ca04 c000e024 c344be44 c344be38 c012d968 bf001a84 c344be64 c344be48
[    3.812164] be40: c012c8ac c012d95c 00000000 c048a478 c048a4ac bf0037f8 c344be84 c344be68
[    3.833740] be60: c012ca74 c012c80c 20000013 00000000 c344be88 bf0037f8 c344beac c344be88
[    3.855468] be80: c012b038 c012ca14 c38093cc c383ee10 bf0037f8 c35be5a0 c049d5e8 00000000
[    3.877166] bea0: c344bebc c344beb0 c012c40c c012aff4 c344beec c344bec0 c012bfc0 c012c3fc
[    3.898834] bec0: bf00378c 00000000 c344beec bf0037f8 00067f39 00000000 00005c44 c000e024
[    3.920837] bee0: c344bf14 c344bef0 c012cd54 c012befc c04ce080 00067f39 00000000 00005c44
[    3.943023] bf00: c000e024 bf006000 c344bf24 c344bf18 c012db14 c012ccc0 c344bf3c c344bf28
[    3.965423] bf20: bf00604c c012dad8 c344a000 bf003834 c344bf7c c344bf40 c00087ac bf006010
[    3.987976] bf40: 0000000f bf003834 00067f39 00000000 00005c44 bf003834 00067f39 00000000
[    4.010711] bf60: 00005c44 c000e024 c344a000 00000000 c344bfa4 c344bf80 c004c35c c0008720
[    4.033569] bf80: c344bfac c344bf90 01422192 01427ea0 00000000 00000080 00000000 c344bfa8
[    4.056518] bfa0: c000dec0 c004c2f0 01422192 01427ea0 01427ea0 00005c44 00067f39 00000000
[    4.079406] bfc0: 01422192 01427ea0 00000000 00000080 b6e11008 014221aa be941fcc b6e1e008
[    4.102569] bfe0: b6ef6300 be941758 0000e93c b6ef6310 60000010 01427ea0 00000000 00000000
[    4.125946] Backtrace:
[    4.143463] [<bf0030e4>] (ohci_omap_init+0x0/0x144 [ohci_hcd]) from [<c0150ff0>] (usb_add_hcd+0x1b8/0x61c)
[    4.183898]  r6:c049e62c r5:00000000 r4:c342d620 r3:bf0030e4
[    4.205596] [<c0150e38>] (usb_add_hcd+0x0/0x61c) from [<bf001bf0>] (ohci_hcd_omap_drv_probe+0x17c/0x224 [ohci_hcd])
[    4.248138] [<bf001a74>] (ohci_hcd_omap_drv_probe+0x0/0x224 [ohci_hcd]) from [<c012d968>] (platform_drv_probe+0x1c/0x20)
[    4.292144]  r8:c000e024 r7:c012ca04 r6:bf0037f8 r5:c048a4ac r4:c048a478
[    4.316192] [<c012d94c>] (platform_drv_probe+0x0/0x20) from [<c012c8ac>] (driver_probe_device+0xb0/0x208)
[    4.360168] [<c012c7fc>] (driver_probe_device+0x0/0x208) from [<c012ca74>] (__driver_attach+0x70/0x94)
[    4.405548]  r6:bf0037f8 r5:c048a4ac r4:c048a478 r3:00000000
[    4.429809] [<c012ca04>] (__driver_attach+0x0/0x94) from [<c012b038>] (bus_for_each_dev+0x54/0x90)
[    4.475708]  r6:bf0037f8 r5:c344be88 r4:00000000 r3:20000013
[    4.500366] [<c012afe4>] (bus_for_each_dev+0x0/0x90) from [<c012c40c>] (driver_attach+0x20/0x28)
[    4.528442]  r7:00000000 r6:c049d5e8 r5:c35be5a0 r4:bf0037f8
[    4.553466] [<c012c3ec>] (driver_attach+0x0/0x28) from [<c012bfc0>] (bus_add_driver+0xd4/0x228)
[    4.581878] [<c012beec>] (bus_add_driver+0x0/0x228) from [<c012cd54>] (driver_register+0xa4/0x134)
[    4.629730]  r8:c000e024 r7:00005c44 r6:00000000 r5:00067f39 r4:bf0037f8
[    4.656738] [<c012ccb0>] (driver_register+0x0/0x134) from [<c012db14>] (platform_driver_register+0x4c/0x60)
[    4.706542] [<c012dac8>] (platform_driver_register+0x0/0x60) from [<bf00604c>] (ohci_hcd_mod_init+0x4c/0x8c [ohci_hcd])
[    4.757843] [<bf006000>] (ohci_hcd_mod_init+0x0/0x8c [ohci_hcd]) from [<c00087ac>] (do_one_initcall+0x9c/0x174)
[    4.808990]  r4:bf003834 r3:c344a000
[    4.832641] [<c0008710>] (do_one_initcall+0x0/0x174) from [<c004c35c>] (sys_init_module+0x7c/0x194)
[    4.881530] [<c004c2e0>] (sys_init_module+0x0/0x194) from [<c000dec0>] (ret_fast_syscall+0x0/0x2c)
[    4.930664]  r7:00000080 r6:00000000 r5:01427ea0 r4:01422192
[    4.956481] Code: bad PC value
[    4.978729] ---[ end trace 58280240f08342c4 ]---
[    5.002258] Kernel panic - not syncing: Fatal exception

Fix this by taking a copy of the data. Also mark Amstrad E3's data with
__initdata to save some memory with multi-board kernels.

Signed-off-by: Aaro Koskinen <aaro.koskinen@iki.fi>
Signed-off-by: Tony Lindgren <tony@atomide.com>
koenkooi pushed a commit that referenced this pull request Jan 16, 2013
Pursuant to this review https://lkml.org/lkml/2012/11/12/500
by Stefan Richter, update the TODO file.
- Clarify purpose of TODO file
- Remove firewire item #4. As discussed in this conversation
  https://lkml.org/lkml/2012/11/13/564 knowing the AR buffer size
  is not a hard requirement. The required rx buffer size can be
  determined experimentally.
- Remove firewire item #5. This was a private note for further
  experimentation.
- Change firewire item #1. Change suggested header from uapi header
  to kernel-only header.

Signed-off-by: Peter Hurley <peter@hurleysoftware.com>
Acked-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
koenkooi pushed a commit that referenced this pull request Jan 23, 2013
The following lines of code produce a kernel oops.

fd = socket(PF_FILE, SOCK_STREAM|SOCK_CLOEXEC|SOCK_NONBLOCK, 0);
fchmod(fd, 0666);

[  139.922364] BUG: unable to handle kernel NULL pointer dereference at   (null)
[  139.924982] IP: [<  (null)>]   (null)
[  139.924982] *pde = 00000000
[  139.924982] Oops: 0000 [#5] SMP
[  139.924982] Modules linked in: fuse dm_crypt dm_mod i2c_piix4 serio_raw evdev binfmt_misc button
[  139.924982] Pid: 3070, comm: acpid Tainted: G      D      3.8.0-rc2-kds+ torvalds#465 Bochs Bochs
[  139.924982] EIP: 0060:[<00000000>] EFLAGS: 00010246 CPU: 0
[  139.924982] EIP is at 0x0
[  139.924982] EAX: cf5ef000 EBX: cf5ef000 ECX: c143d600 EDX: c15225f2
[  139.924982] ESI: cf4d2a1c EDI: cf4d2a1c EBP: cc02df10 ESP: cc02dee4
[  139.924982]  DS: 007b ES: 007b FS: 00d8 GS: 0033 SS: 0068
[  139.924982] CR0: 80050033 CR2: 00000000 CR3: 0c059000 CR4: 000006d0
[  139.924982] DR0: 00000000 DR1: 00000000 DR2: 00000000 DR3: 00000000
[  139.924982] DR6: ffff0ff0 DR7: 00000400
[  139.924982] Process acpid (pid: 3070, ti=cc02c000 task=d7705340 task.ti=cc02c000)
[  139.924982] Stack:
[  139.924982]  c1203c88 00000000 cc02def4 cf4d2a1c ae21eefa 471b60d5 1083c1ba c26a5940
[  139.924982]  e891fb5e 00000041 00000004 cc02df1c c1203964 00000000 cc02df4c c10e20c3
[  139.924982]  00000002 00000000 00000000 22222222 c1ff2222 cf5ef000 00000000 d76efb08
[  139.924982] Call Trace:
[  139.924982]  [<c1203c88>] ? evm_update_evmxattr+0x5b/0x62
[  139.924982]  [<c1203964>] evm_inode_post_setattr+0x22/0x26
[  139.924982]  [<c10e20c3>] notify_change+0x25f/0x281
[  139.924982]  [<c10cbf56>] chmod_common+0x59/0x76
[  139.924982]  [<c10e27a1>] ? put_unused_fd+0x33/0x33
[  139.924982]  [<c10cca09>] sys_fchmod+0x39/0x5c
[  139.924982]  [<c13f4f30>] syscall_call+0x7/0xb
[  139.924982] Code:  Bad EIP value.

This happens because sockets do not define the removexattr operation.
Before removing the xattr, verify the removexattr function pointer is
not NULL.

Signed-off-by: Dmitry Kasatkin <dmitry.kasatkin@intel.com>
Signed-off-by: Mimi Zohar <zohar@linux.vnet.ibm.com>
Cc: stable@vger.kernel.org
Signed-off-by: James Morris <james.l.morris@oracle.com>
koenkooi pushed a commit that referenced this pull request Mar 21, 2013
[ Upstream commit 9cb6cb7 ]

The following script will produce a kernel oops:

    sudo ip netns add v
    sudo ip netns exec v ip ad add 127.0.0.1/8 dev lo
    sudo ip netns exec v ip link set lo up
    sudo ip netns exec v ip ro add 224.0.0.0/4 dev lo
    sudo ip netns exec v ip li add vxlan0 type vxlan id 42 group 239.1.1.1 dev lo
    sudo ip netns exec v ip link set vxlan0 up
    sudo ip netns del v

where inspect by gdb:

    Program received signal SIGSEGV, Segmentation fault.
    [Switching to Thread 107]
    0xffffffffa0289e33 in ?? ()
    (gdb) bt
    #0  vxlan_leave_group (dev=0xffff88001bafa000) at drivers/net/vxlan.c:533
    #1  vxlan_stop (dev=0xffff88001bafa000) at drivers/net/vxlan.c:1087
    #2  0xffffffff812cc498 in __dev_close_many (head=head@entry=0xffff88001f2e7dc8) at net/core/dev.c:1299
    #3  0xffffffff812cd920 in dev_close_many (head=head@entry=0xffff88001f2e7dc8) at net/core/dev.c:1335
    #4  0xffffffff812cef31 in rollback_registered_many (head=head@entry=0xffff88001f2e7dc8) at net/core/dev.c:4851
    #5  0xffffffff812cf040 in unregister_netdevice_many (head=head@entry=0xffff88001f2e7dc8) at net/core/dev.c:5752
    #6  0xffffffff812cf1ba in default_device_exit_batch (net_list=0xffff88001f2e7e18) at net/core/dev.c:6170
    #7  0xffffffff812cab27 in cleanup_net (work=<optimized out>) at net/core/net_namespace.c:302
    #8  0xffffffff810540ef in process_one_work (worker=0xffff88001ba9ed40, work=0xffffffff8167d020) at kernel/workqueue.c:2157
    #9  0xffffffff810549d0 in worker_thread (__worker=__worker@entry=0xffff88001ba9ed40) at kernel/workqueue.c:2276
    torvalds#10 0xffffffff8105870c in kthread (_create=0xffff88001f2e5d68) at kernel/kthread.c:168
    torvalds#11 <signal handler called>
    torvalds#12 0x0000000000000000 in ?? ()
    torvalds#13 0x0000000000000000 in ?? ()
    (gdb) fr 0
    #0  vxlan_leave_group (dev=0xffff88001bafa000) at drivers/net/vxlan.c:533
    533		struct sock *sk = vn->sock->sk;
    (gdb) l
    528	static int vxlan_leave_group(struct net_device *dev)
    529	{
    530		struct vxlan_dev *vxlan = netdev_priv(dev);
    531		struct vxlan_net *vn = net_generic(dev_net(dev), vxlan_net_id);
    532		int err = 0;
    533		struct sock *sk = vn->sock->sk;
    534		struct ip_mreqn mreq = {
    535			.imr_multiaddr.s_addr	= vxlan->gaddr,
    536			.imr_ifindex		= vxlan->link,
    537		};
    (gdb) p vn->sock
    $4 = (struct socket *) 0x0

The kernel calls `vxlan_exit_net` when deleting the netns before shutting down
vxlan interfaces. Later the removal of all vxlan interfaces, where `vn->sock`
is already gone causes the oops. so we should manually shutdown all interfaces
before deleting `vn->sock` as the patch does.

Signed-off-by: Zang MingJie <zealot0630@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
koenkooi pushed a commit that referenced this pull request Mar 29, 2013
commit 38d78e5 upstream.

mnt_drop_write() must be called only if mnt_want_write() succeeded,
otherwise the mnt_writers counter will diverge.

mnt_writers counters are used to check if remounting FS as read-only is
OK, so after an extra mnt_drop_write() call, it would be impossible to
remount mqueue FS as read-only.  Besides, on umount a warning would be
printed like this one:

  =====================================
  [ BUG: bad unlock balance detected! ]
  3.9.0-rc3 #5 Not tainted
  -------------------------------------
  a.out/12486 is trying to release lock (sb_writers) at:
  mnt_drop_write+0x1f/0x30
  but there are no more locks to release!

Signed-off-by: Vladimir Davydov <vdavydov@parallels.com>
Cc: Doug Ledford <dledford@redhat.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
koenkooi pushed a commit that referenced this pull request May 13, 2013
commit f7a1dd6 upstream.

The reason for this patch is crash in kmemdup
caused by returning from get_callid with uniialized
matchoff and matchlen.

Removing Zero check of matchlen since it's done by ct_sip_get_header()

BUG: unable to handle kernel paging request at ffff880457b5763f
IP: [<ffffffff810df7fc>] kmemdup+0x2e/0x35
PGD 27f6067 PUD 0
Oops: 0000 [#1] PREEMPT SMP
Modules linked in: xt_state xt_helper nf_conntrack_ipv6 nf_defrag_ipv6 ip6table_mangle xt_connmark xt_conntrack ip6_tables nf_conntrack_ftp ip_vs_ftp nf_nat xt_tcpudp iptable_mangle xt_mark ip_tables x_tables ip_vs_rr ip_vs_lblcr ip_vs_pe_sip ip_vs nf_conntrack_sip nf_conntrack bonding igb i2c_algo_bit i2c_core
CPU 5
Pid: 0, comm: swapper/5 Not tainted 3.9.0-rc5+ #5                  /S1200KP
RIP: 0010:[<ffffffff810df7fc>]  [<ffffffff810df7fc>] kmemdup+0x2e/0x35
RSP: 0018:ffff8803fea03648  EFLAGS: 00010282
RAX: ffff8803d61063e0 RBX: 0000000000000003 RCX: 0000000000000003
RDX: 0000000000000003 RSI: ffff880457b5763f RDI: ffff8803d61063e0
RBP: ffff8803fea03658 R08: 0000000000000008 R09: 0000000000000011
R10: 0000000000000011 R11: 00ffffffff81a8a3 R12: ffff880457b5763f
R13: ffff8803d67f786a R14: ffff8803fea03730 R15: ffffffffa0098e90
FS:  0000000000000000(0000) GS:ffff8803fea00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffff880457b5763f CR3: 0000000001a0c000 CR4: 00000000001407e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Process swapper/5 (pid: 0, threadinfo ffff8803ee18c000, task ffff8803ee18a480)
Stack:
 ffff8803d822a080 000000000000001c ffff8803fea036c8 ffffffffa000937a
 ffffffff81f0d8a0 000000038135fdd5 ffff880300000014 ffff880300110000
 ffffffff150118ac ffff8803d7e8a000 ffff88031e0118ac 0000000000000000
Call Trace:
 <IRQ>

 [<ffffffffa000937a>] ip_vs_sip_fill_param+0x13a/0x187 [ip_vs_pe_sip]
 [<ffffffffa007b209>] ip_vs_sched_persist+0x2c6/0x9c3 [ip_vs]
 [<ffffffff8107dc53>] ? __lock_acquire+0x677/0x1697
 [<ffffffff8100972e>] ? native_sched_clock+0x3c/0x7d
 [<ffffffff8100972e>] ? native_sched_clock+0x3c/0x7d
 [<ffffffff810649bc>] ? sched_clock_cpu+0x43/0xcf
 [<ffffffffa007bb1e>] ip_vs_schedule+0x181/0x4ba [ip_vs]
...

Signed-off-by: Hans Schillstrom <hans@schillstrom.com>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
Cc: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
koenkooi pushed a commit that referenced this pull request Jul 2, 2013
1. Background

Previously, if f2fs tries to move data blocks of an *evicting* inode during the
cleaning process, it stops the process incompletely and then restarts the whole
process, since it needs a locked inode to grab victim data pages in its address
space. In order to get a locked inode, iget_locked() by f2fs_iget() is normally
used, but, it waits if the inode is on freeing.

So, here is a deadlock scenario.
1. f2fs_evict_inode()       <- inode "A"
  2. f2fs_balance_fs()
    3. f2fs_gc()
      4. gc_data_segment()
        5. f2fs_iget()      <- inode "A" too!

If step #1 and #5 treat a same inode "A", step #5 would fall into deadlock since
the inode "A" is on freeing. In order to resolve this, f2fs_iget_nowait() which
skips __wait_on_freeing_inode() was introduced in step #5, and stops f2fs_gc()
to complete f2fs_evict_inode().

1. f2fs_evict_inode()           <- inode "A"
  2. f2fs_balance_fs()
    3. f2fs_gc()
      4. gc_data_segment()
        5. f2fs_iget_nowait()   <- inode "A", then stop f2fs_gc() w/ -ENOENT

2. Problem and Solution

In the above scenario, however, f2fs cannot finish f2fs_evict_inode() only if:
 o there are not enough free sections, and
 o f2fs_gc() tries to move data blocks of the *evicting* inode repeatedly.

So, the final solution is to use f2fs_iget() and remove f2fs_balance_fs() in
f2fs_evict_inode().
The f2fs_evict_inode() actually truncates all the data and node blocks, which
means that it doesn't produce any dirty node pages accordingly.
So, we don't need to do f2fs_balance_fs() in practical.

Signed-off-by: Jaegeuk Kim <jaegeuk.kim@samsung.com>
koenkooi pushed a commit that referenced this pull request Jul 2, 2013
For now this will suffice for all platforms, later exotic ones needs to
get this from DeviceTree

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>
Cc: Arnd Bergmann <arnd@arndb.de>
koenkooi pushed a commit that referenced this pull request Jul 2, 2013
…ernel/git/vgupta/arc

Pull new ARC architecture from Vineet Gupta:
 "Initial ARC Linux port with some fixes on top for 3.9-rc1:

  I would like to introduce the Linux port to ARC Processors (from
  Synopsys) for 3.9-rc1.  The patch-set has been discussed on the public
  lists since Nov and has received a fair bit of review, specially from
  Arnd, tglx, Al and other subsystem maintainers for DeviceTree, kgdb...

  The arch bits are in arch/arc, some asm-generic changes (acked by
  Arnd), a minor change to PARISC (acked by Helge).

  The series is a touch bigger for a new port for 2 main reasons:

   1. It enables a basic kernel in first sub-series and adds
      ptrace/kgdb/.. later

   2. Some of the fallout of review (DeviceTree support, multi-platform-
      image support) were added on top of orig series, primarily to
      record the revision history.

  This updated pull request additionally contains

   - fixes due to our GNU tools catching up with the new syscall/ptrace
     ABI

   - some (minor) cross-arch Kconfig updates."

* tag 'arc-v3.9-rc1-late' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc: (82 commits)
  ARC: split elf.h into uapi and export it for userspace
  ARC: Fixup the current ABI version
  ARC: gdbserver using regset interface possibly broken
  ARC: Kconfig cleanup tracking cross-arch Kconfig pruning in merge window
  ARC: make a copy of flat DT
  ARC: [plat-arcfpga] DT arc-uart bindings change: "baud" => "current-speed"
  ARC: Ensure CONFIG_VIRT_TO_BUS is not enabled
  ARC: Fix pt_orig_r8 access
  ARC: [3.9] Fallout of hlist iterator update
  ARC: 64bit RTSC timestamp hardware issue
  ARC: Don't fiddle with non-existent caches
  ARC: Add self to MAINTAINERS
  ARC: Provide a default serial.h for uart drivers needing BASE_BAUD
  ARC: [plat-arcfpga] defconfig for fully loaded ARC Linux
  ARC: [Review] Multi-platform image #8: platform registers SMP callbacks
  ARC: [Review] Multi-platform image #7: SMP common code to use callbacks
  ARC: [Review] Multi-platform image #6: cpu-to-dma-addr optional
  ARC: [Review] Multi-platform image #5: NR_IRQS defined by ARC core
  ARC: [Review] Multi-platform image #4: Isolate platform headers
  ARC: [Review] Multi-platform image #3: switch to board callback
  ...
koenkooi pushed a commit that referenced this pull request Jul 2, 2013
The following script will produce a kernel oops:

    sudo ip netns add v
    sudo ip netns exec v ip ad add 127.0.0.1/8 dev lo
    sudo ip netns exec v ip link set lo up
    sudo ip netns exec v ip ro add 224.0.0.0/4 dev lo
    sudo ip netns exec v ip li add vxlan0 type vxlan id 42 group 239.1.1.1 dev lo
    sudo ip netns exec v ip link set vxlan0 up
    sudo ip netns del v

where inspect by gdb:

    Program received signal SIGSEGV, Segmentation fault.
    [Switching to Thread 107]
    0xffffffffa0289e33 in ?? ()
    (gdb) bt
    #0  vxlan_leave_group (dev=0xffff88001bafa000) at drivers/net/vxlan.c:533
    #1  vxlan_stop (dev=0xffff88001bafa000) at drivers/net/vxlan.c:1087
    #2  0xffffffff812cc498 in __dev_close_many (head=head@entry=0xffff88001f2e7dc8) at net/core/dev.c:1299
    #3  0xffffffff812cd920 in dev_close_many (head=head@entry=0xffff88001f2e7dc8) at net/core/dev.c:1335
    #4  0xffffffff812cef31 in rollback_registered_many (head=head@entry=0xffff88001f2e7dc8) at net/core/dev.c:4851
    #5  0xffffffff812cf040 in unregister_netdevice_many (head=head@entry=0xffff88001f2e7dc8) at net/core/dev.c:5752
    #6  0xffffffff812cf1ba in default_device_exit_batch (net_list=0xffff88001f2e7e18) at net/core/dev.c:6170
    #7  0xffffffff812cab27 in cleanup_net (work=<optimized out>) at net/core/net_namespace.c:302
    #8  0xffffffff810540ef in process_one_work (worker=0xffff88001ba9ed40, work=0xffffffff8167d020) at kernel/workqueue.c:2157
    #9  0xffffffff810549d0 in worker_thread (__worker=__worker@entry=0xffff88001ba9ed40) at kernel/workqueue.c:2276
    torvalds#10 0xffffffff8105870c in kthread (_create=0xffff88001f2e5d68) at kernel/kthread.c:168
    torvalds#11 <signal handler called>
    torvalds#12 0x0000000000000000 in ?? ()
    torvalds#13 0x0000000000000000 in ?? ()
    (gdb) fr 0
    #0  vxlan_leave_group (dev=0xffff88001bafa000) at drivers/net/vxlan.c:533
    533		struct sock *sk = vn->sock->sk;
    (gdb) l
    528	static int vxlan_leave_group(struct net_device *dev)
    529	{
    530		struct vxlan_dev *vxlan = netdev_priv(dev);
    531		struct vxlan_net *vn = net_generic(dev_net(dev), vxlan_net_id);
    532		int err = 0;
    533		struct sock *sk = vn->sock->sk;
    534		struct ip_mreqn mreq = {
    535			.imr_multiaddr.s_addr	= vxlan->gaddr,
    536			.imr_ifindex		= vxlan->link,
    537		};
    (gdb) p vn->sock
    $4 = (struct socket *) 0x0

The kernel calls `vxlan_exit_net` when deleting the netns before shutting down
vxlan interfaces. Later the removal of all vxlan interfaces, where `vn->sock`
is already gone causes the oops. so we should manually shutdown all interfaces
before deleting `vn->sock` as the patch does.

Signed-off-by: Zang MingJie <zealot0630@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
koenkooi pushed a commit that referenced this pull request Jul 2, 2013
mnt_drop_write() must be called only if mnt_want_write() succeeded,
otherwise the mnt_writers counter will diverge.

mnt_writers counters are used to check if remounting FS as read-only is
OK, so after an extra mnt_drop_write() call, it would be impossible to
remount mqueue FS as read-only.  Besides, on umount a warning would be
printed like this one:

  =====================================
  [ BUG: bad unlock balance detected! ]
  3.9.0-rc3 #5 Not tainted
  -------------------------------------
  a.out/12486 is trying to release lock (sb_writers) at:
  mnt_drop_write+0x1f/0x30
  but there are no more locks to release!

Signed-off-by: Vladimir Davydov <vdavydov@parallels.com>
Cc: Doug Ledford <dledford@redhat.com>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
koenkooi pushed a commit that referenced this pull request Jul 2, 2013
Add a new ioctl, EXT4_IOC_SWAP_BOOT which swaps i_blocks and
associated attributes (like i_blocks, i_size, i_flags, ...) from the
specified inode with inode EXT4_BOOT_LOADER_INO (#5). This is
typically used to store a boot loader in a secure part of the
filesystem, where it can't be changed by a normal user by accident.
The data blocks of the previous boot loader will be associated with
the given inode.

This usercode program is a simple example of the usage:

int main(int argc, char *argv[])
{
  int fd;
  int err;

  if ( argc != 2 ) {
    printf("usage: ext4-swap-boot-inode FILE-TO-SWAP\n");
    exit(1);
  }

  fd = open(argv[1], O_WRONLY);
  if ( fd < 0 ) {
    perror("open");
    exit(1);
  }

  err = ioctl(fd, EXT4_IOC_SWAP_BOOT);
  if ( err < 0 ) {
    perror("ioctl");
    exit(1);
  }

  close(fd);
  exit(0);
}

[ Modified by Theodore Ts'o to fix a number of bugs in the original code.]

Signed-off-by: Dr. Tilmann Bubeck <t.bubeck@reinform.de>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
koenkooi pushed a commit that referenced this pull request Jul 2, 2013
Otherwise we get a race between unload and reload of the same module:
the new module doesn't see the old one in the list, but then fails because
it can't register over the still-extant entries in sysfs:

 [  103.981925] ------------[ cut here ]------------
 [  103.986902] WARNING: at fs/sysfs/dir.c:536 sysfs_add_one+0xab/0xd0()
 [  103.993606] Hardware name: CrownBay Platform
 [  103.998075] sysfs: cannot create duplicate filename '/module/pch_gbe'
 [  104.004784] Modules linked in: pch_gbe(+) [last unloaded: pch_gbe]
 [  104.011362] Pid: 3021, comm: modprobe Tainted: G        W    3.9.0-rc5+ #5
 [  104.018662] Call Trace:
 [  104.021286]  [<c103599d>] warn_slowpath_common+0x6d/0xa0
 [  104.026933]  [<c1168c8b>] ? sysfs_add_one+0xab/0xd0
 [  104.031986]  [<c1168c8b>] ? sysfs_add_one+0xab/0xd0
 [  104.037000]  [<c1035a4e>] warn_slowpath_fmt+0x2e/0x30
 [  104.042188]  [<c1168c8b>] sysfs_add_one+0xab/0xd0
 [  104.046982]  [<c1168dbe>] create_dir+0x5e/0xa0
 [  104.051633]  [<c1168e78>] sysfs_create_dir+0x78/0xd0
 [  104.056774]  [<c1262bc3>] kobject_add_internal+0x83/0x1f0
 [  104.062351]  [<c126daf6>] ? kvasprintf+0x46/0x60
 [  104.067231]  [<c1262ebd>] kobject_add_varg+0x2d/0x50
 [  104.072450]  [<c1262f07>] kobject_init_and_add+0x27/0x30
 [  104.078075]  [<c1089240>] mod_sysfs_setup+0x80/0x540
 [  104.083207]  [<c1260851>] ? module_bug_finalize+0x51/0xc0
 [  104.088720]  [<c108ab29>] load_module+0x1429/0x18b0

We can teardown sysfs first, then to be sure, put the state in
MODULE_STATE_UNFORMED so it's ignored while we deconstruct it.

Reported-by: Veaceslav Falico <vfalico@redhat.com>
Tested-by: Veaceslav Falico <vfalico@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
koenkooi pushed a commit that referenced this pull request Jul 2, 2013
The reason for this patch is crash in kmemdup
caused by returning from get_callid with uniialized
matchoff and matchlen.

Removing Zero check of matchlen since it's done by ct_sip_get_header()

BUG: unable to handle kernel paging request at ffff880457b5763f
IP: [<ffffffff810df7fc>] kmemdup+0x2e/0x35
PGD 27f6067 PUD 0
Oops: 0000 [#1] PREEMPT SMP
Modules linked in: xt_state xt_helper nf_conntrack_ipv6 nf_defrag_ipv6 ip6table_mangle xt_connmark xt_conntrack ip6_tables nf_conntrack_ftp ip_vs_ftp nf_nat xt_tcpudp iptable_mangle xt_mark ip_tables x_tables ip_vs_rr ip_vs_lblcr ip_vs_pe_sip ip_vs nf_conntrack_sip nf_conntrack bonding igb i2c_algo_bit i2c_core
CPU 5
Pid: 0, comm: swapper/5 Not tainted 3.9.0-rc5+ #5                  /S1200KP
RIP: 0010:[<ffffffff810df7fc>]  [<ffffffff810df7fc>] kmemdup+0x2e/0x35
RSP: 0018:ffff8803fea03648  EFLAGS: 00010282
RAX: ffff8803d61063e0 RBX: 0000000000000003 RCX: 0000000000000003
RDX: 0000000000000003 RSI: ffff880457b5763f RDI: ffff8803d61063e0
RBP: ffff8803fea03658 R08: 0000000000000008 R09: 0000000000000011
R10: 0000000000000011 R11: 00ffffffff81a8a3 R12: ffff880457b5763f
R13: ffff8803d67f786a R14: ffff8803fea03730 R15: ffffffffa0098e90
FS:  0000000000000000(0000) GS:ffff8803fea00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffff880457b5763f CR3: 0000000001a0c000 CR4: 00000000001407e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
Process swapper/5 (pid: 0, threadinfo ffff8803ee18c000, task ffff8803ee18a480)
Stack:
 ffff8803d822a080 000000000000001c ffff8803fea036c8 ffffffffa000937a
 ffffffff81f0d8a0 000000038135fdd5 ffff880300000014 ffff880300110000
 ffffffff150118ac ffff8803d7e8a000 ffff88031e0118ac 0000000000000000
Call Trace:
 <IRQ>

 [<ffffffffa000937a>] ip_vs_sip_fill_param+0x13a/0x187 [ip_vs_pe_sip]
 [<ffffffffa007b209>] ip_vs_sched_persist+0x2c6/0x9c3 [ip_vs]
 [<ffffffff8107dc53>] ? __lock_acquire+0x677/0x1697
 [<ffffffff8100972e>] ? native_sched_clock+0x3c/0x7d
 [<ffffffff8100972e>] ? native_sched_clock+0x3c/0x7d
 [<ffffffff810649bc>] ? sched_clock_cpu+0x43/0xcf
 [<ffffffffa007bb1e>] ip_vs_schedule+0x181/0x4ba [ip_vs]
...

Signed-off-by: Hans Schillstrom <hans@schillstrom.com>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
koenkooi pushed a commit that referenced this pull request Jul 2, 2013
This can easily be triggered if a new CPU is added (via
ACPI hotplug mechanism) and from user-space you do:

   echo 1 > /sys/devices/system/cpu/cpu3/online

(or wait for UDEV to do it) on a newly appeared physical CPU.

The deadlock is that the "store_online" in drivers/base/cpu.c
takes the cpu_hotplug_driver_lock() lock, then calls "cpu_up".
"cpu_up" eventually ends up calling "save_mc_for_early"
which also takes the cpu_hotplug_driver_lock() lock.

And here is that lockdep thinks of it:

 smpboot: Stack at about ffff880075c39f44
 smpboot: CPU3: has booted.
 microcode: CPU3 sig=0x206a7, pf=0x2, revision=0x25

 =============================================
 [ INFO: possible recursive locking detected ]
 3.9.0upstream-10129-g167af0e #1 Not tainted
 ---------------------------------------------
 sh/2487 is trying to acquire lock:
  (x86_cpu_hotplug_driver_mutex){+.+.+.}, at: [<ffffffff81075512>] cpu_hotplug_driver_lock+0x12/0x20

 but task is already holding lock:
  (x86_cpu_hotplug_driver_mutex){+.+.+.}, at: [<ffffffff81075512>] cpu_hotplug_driver_lock+0x12/0x20

 other info that might help us debug this:
  Possible unsafe locking scenario:

        CPU0
        ----
   lock(x86_cpu_hotplug_driver_mutex);
   lock(x86_cpu_hotplug_driver_mutex);

  *** DEADLOCK ***

  May be due to missing lock nesting notation

 6 locks held by sh/2487:
  #0:  (sb_writers#5){.+.+.+}, at: [<ffffffff811ca48d>] vfs_write+0x17d/0x190
  #1:  (&buffer->mutex){+.+.+.}, at: [<ffffffff812464ef>] sysfs_write_file+0x3f/0x160
  #2:  (s_active#20){.+.+.+}, at: [<ffffffff81246578>] sysfs_write_file+0xc8/0x160
  #3:  (x86_cpu_hotplug_driver_mutex){+.+.+.}, at: [<ffffffff81075512>] cpu_hotplug_driver_lock+0x12/0x20
  #4:  (cpu_add_remove_lock){+.+.+.}, at: [<ffffffff810961c2>] cpu_maps_update_begin+0x12/0x20
  #5:  (cpu_hotplug.lock){+.+.+.}, at: [<ffffffff810962a7>] cpu_hotplug_begin+0x27/0x60

Suggested-and-Acked-by: Borislav Petkov <bp@alien8.de>
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Cc: fenghua.yu@intel.com
Cc: xen-devel@lists.xensource.com
Cc: stable@vger.kernel.org # for v3.9
Link: http://lkml.kernel.org/r/1368029583-23337-1-git-send-email-konrad.wilk@oracle.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
koenkooi pushed a commit that referenced this pull request Jul 2, 2013
Make sure that any open relayfs files are closed before
unregistering with mac80211, otherwise this crash is seen:

[ 1331.097846] BUG: unable to handle kernel paging request at 6b6b6b8b
[ 1331.098170] IP: [<c063d0d6>] debugfs_remove+0x26/0x80
[ 1331.098170] *pdpt = 000000002f9aa001 *pde = 0000000000000000
[ 1331.098170] Oops: 0000 [#1] PREEMPT SMP
[ 1331.098170] Modules linked in: iptable_raw xt_CT nf_conntrack_ipv4 nf_defrag]
[ 1331.098170] Pid: 4794, comm: rmmod Tainted: G        WC   3.9.1+ #5 To Be Fi.
[ 1331.098170] EIP: 0060:[<c063d0d6>] EFLAGS: 00010202 CPU: 0
[ 1331.098170] EIP is at debugfs_remove+0x26/0x80
[ 1331.098170] EAX: f2f3acd0 EBX: f2f3acd0 ECX: 00000006 EDX: f8622348
[ 1331.098170] ESI: 6b6b6b6b EDI: 00000001 EBP: ee251e14 ESP: ee251e0c
[ 1331.098170]  DS: 007b ES: 007b FS: 00d8 GS: 00e0 SS: 0068
[ 1331.098170] CR0: 8005003b CR2: 6b6b6b8b CR3: 2e7b7000 CR4: 000007e0
[ 1331.098170] DR0: 00000000 DR1: 00000000 DR2: 00000000 DR3: 00000000
[ 1331.098170] DR6: ffff0ff0 DR7: 00000400
[ 1331.098170] Process rmmod (pid: 4794, ti=ee250000 task=efaa2560 task.ti=ee25)
[ 1331.098170] Stack:
[ 1331.098170]  f241e170 0000000a ee251e1c f861394d ee251e28 c04e3088 f241e170 4
[ 1331.098170]  c04e30fe f45482b0 ee251e54 c04e3187 f25e86b0 ee251e54 f8618748 0
[ 1331.098170]  0000000a 00000001 ee251e68 f860065b f2509e20 f25085a0 f5b6e8a4 8
[ 1331.098170] Call Trace:
[ 1331.098170]  [<f861394d>] remove_buf_file_handler+0xd/0x20 [ath9k]
[ 1331.098170]  [<c04e3088>] relay_remove_buf+0x18/0x30
[ 1331.098170]  [<c04e30fe>] relay_close_buf+0x2e/0x40
[ 1331.098170]  [<c04e3187>] relay_close+0x77/0xf0
[ 1331.098170]  [<f8618748>] ? dpd_exit+0x38/0x40 [ath9k]
[ 1331.098170]  [<f860065b>] ath9k_deinit_softc+0x8b/0xa0 [ath9k]
[ 1331.098170]  [<f86006b8>] ath9k_deinit_device+0x48/0x60 [ath9k]
[ 1331.098170]  [<f86107f1>] ath_pci_remove+0x31/0x50 [ath9k]
[ 1331.098170]  [<c06dbff8>] pci_device_remove+0x38/0xc0
[ 1331.098170]  [<c079daa4>] __device_release_driver+0x64/0xc0
[ 1331.098170]  [<c079db97>] driver_detach+0x97/0xa0
[ 1331.098170]  [<c079cacc>] bus_remove_driver+0x6c/0xe0
[ 1331.098170]  [<c079c197>] ? bus_put+0x17/0x20
[ 1331.098170]  [<c079cae3>] ? bus_remove_driver+0x83/0xe0
[ 1331.098170]  [<c079e709>] driver_unregister+0x49/0x80
[ 1331.098170]  [<c06dc138>] pci_unregister_driver+0x18/0x80
[ 1331.098170]  [<f8610602>] ath_pci_exit+0x12/0x20 [ath9k]
[ 1331.098170]  [<f8619ce0>] ath9k_exit+0x17/0x337 [ath9k]
[ 1331.098170]  [<c09e537d>] ? mutex_unlock+0xd/0x10
[ 1331.098170]  [<c04bd36c>] sys_delete_module+0x17c/0x250
[ 1331.098170]  [<c0540dc4>] ? do_munmap+0x244/0x2d0
[ 1331.098170]  [<c0540e96>] ? vm_munmap+0x46/0x60
[ 1331.098170]  [<c09e8dc4>] ? restore_all+0xf/0xf
[ 1331.098170]  [<c09ebf50>] ? __do_page_fault+0x4c0/0x4c0
[ 1331.098170]  [<c04b18e4>] ? trace_hardirqs_on_caller+0xf4/0x180
[ 1331.098170]  [<c09ef28d>] sysenter_do_call+0x12/0x38
[ 1331.098170] Code: 90 8d 74 26 00 55 89 e5 83 ec 08 89 1c 24 89 74 24 04 3e 82
[ 1331.098170] EIP: [<c063d0d6>] debugfs_remove+0x26/0x80 SS:ESP 0068:ee251e0c
[ 1331.098170] CR2: 000000006b6b6b8b
[ 1331.727971] ---[ end trace b5bb9f2066cef7f9 ]---

Cc: <stable@vger.kernel.org>
Acked-by: Simon Wunderlich <siwu@hrz.tu-chemnitz.de>
Tested-by: Ben Greear <greearb@candelatech.com>
Signed-off-by: Sujith Manoharan <c_manoha@qca.qualcomm.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
koenkooi pushed a commit that referenced this pull request Jul 2, 2013
Daniel Petre reported crashes in icmp_dst_unreach() with following call
graph:

#3 [ffff88003fc03938] __stack_chk_fail at ffffffff81037f77
#4 [ffff88003fc03948] icmp_send at ffffffff814d5fec
#5 [ffff88003fc03ae8] ipv4_link_failure at ffffffff814a1795
#6 [ffff88003fc03af8] ipgre_tunnel_xmit at ffffffff814e7965
#7 [ffff88003fc03b78] dev_hard_start_xmit at ffffffff8146e032
#8 [ffff88003fc03bc8] sch_direct_xmit at ffffffff81487d66
#9 [ffff88003fc03c08] __qdisc_run at ffffffff81487efd
torvalds#10 [ffff88003fc03c48] dev_queue_xmit at ffffffff8146e5a7
torvalds#11 [ffff88003fc03c88] ip_finish_output at ffffffff814ab596

Daniel found a similar problem mentioned in
 http://lkml.indiana.edu/hypermail/linux/kernel/1007.0/00961.html

And indeed this is the root cause : skb->cb[] contains data fooling IP
stack.

We must clear IPCB in ip_tunnel_xmit() sooner in case dst_link_failure()
is called. Or else skb->cb[] might contain garbage from GSO segmentation
layer.

A similar fix was tested on linux-3.9, but gre code was refactored in
linux-3.10. I'll send patches for stable kernels as well.

Many thanks to Daniel for providing reports, patches and testing !

Reported-by: Daniel Petre <daniel.petre@rcs-rds.ro>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
koenkooi pushed a commit that referenced this pull request Jul 2, 2013
In Steven Rostedt's words:

> I've been debugging the last couple of days why my tests have been
> locking up. One of my tracing tests, runs all available tracers. The
> lockup always happened with the mmiotrace, which is used to trace
> interactions between priority drivers and the kernel. But to do this
> easily, when the tracer gets registered, it disables all but the boot
> CPUs. The lockup always happened after it got done disabling the CPUs.
>
> Then I decided to try this:
>
> while :; do
> 	for i in 1 2 3; do
> 		echo 0 > /sys/devices/system/cpu/cpu$i/online
> 	done
> 	for i in 1 2 3; do
> 		echo 1 > /sys/devices/system/cpu/cpu$i/online
> 	done
> done
>
> Well, sure enough, that locked up too, with the same users. Doing a
> sysrq-w (showing all blocked tasks):
>
> [ 2991.344562]   task                        PC stack   pid father
> [ 2991.344562] rcu_preempt     D ffff88007986fdf8     0    10      2 0x00000000
> [ 2991.344562]  ffff88007986fc98 0000000000000002 ffff88007986fc48 0000000000000908
> [ 2991.344562]  ffff88007986c280 ffff88007986ffd8 ffff88007986ffd8 00000000001d3c80
> [ 2991.344562]  ffff880079248a40 ffff88007986c280 0000000000000000 00000000fffd4295
> [ 2991.344562] Call Trace:
> [ 2991.344562]  [<ffffffff815437ba>] schedule+0x64/0x66
> [ 2991.344562]  [<ffffffff81541750>] schedule_timeout+0xbc/0xf9
> [ 2991.344562]  [<ffffffff8154bec0>] ? ftrace_call+0x5/0x2f
> [ 2991.344562]  [<ffffffff81049513>] ? cascade+0xa8/0xa8
> [ 2991.344562]  [<ffffffff815417ab>] schedule_timeout_uninterruptible+0x1e/0x20
> [ 2991.344562]  [<ffffffff810c980c>] rcu_gp_kthread+0x502/0x94b
> [ 2991.344562]  [<ffffffff81062791>] ? __init_waitqueue_head+0x50/0x50
> [ 2991.344562]  [<ffffffff810c930a>] ? rcu_gp_fqs+0x64/0x64
> [ 2991.344562]  [<ffffffff81061cdb>] kthread+0xb1/0xb9
> [ 2991.344562]  [<ffffffff81091e31>] ? lock_release_holdtime.part.23+0x4e/0x55
> [ 2991.344562]  [<ffffffff81061c2a>] ? __init_kthread_worker+0x58/0x58
> [ 2991.344562]  [<ffffffff8154c1dc>] ret_from_fork+0x7c/0xb0
> [ 2991.344562]  [<ffffffff81061c2a>] ? __init_kthread_worker+0x58/0x58
> [ 2991.344562] kworker/0:1     D ffffffff81a30680     0    47      2 0x00000000
> [ 2991.344562] Workqueue: events cpuset_hotplug_workfn
> [ 2991.344562]  ffff880078dbbb58 0000000000000002 0000000000000006 00000000000000d8
> [ 2991.344562]  ffff880078db8100 ffff880078dbbfd8 ffff880078dbbfd8 00000000001d3c80
> [ 2991.344562]  ffff8800779ca5c0 ffff880078db8100 ffffffff81541fcf 0000000000000000
> [ 2991.344562] Call Trace:
> [ 2991.344562]  [<ffffffff81541fcf>] ? __mutex_lock_common+0x3d4/0x609
> [ 2991.344562]  [<ffffffff815437ba>] schedule+0x64/0x66
> [ 2991.344562]  [<ffffffff81543a39>] schedule_preempt_disabled+0x18/0x24
> [ 2991.344562]  [<ffffffff81541fcf>] __mutex_lock_common+0x3d4/0x609
> [ 2991.344562]  [<ffffffff8103d11b>] ? get_online_cpus+0x3c/0x50
> [ 2991.344562]  [<ffffffff8103d11b>] ? get_online_cpus+0x3c/0x50
> [ 2991.344562]  [<ffffffff815422ff>] mutex_lock_nested+0x3b/0x40
> [ 2991.344562]  [<ffffffff8103d11b>] get_online_cpus+0x3c/0x50
> [ 2991.344562]  [<ffffffff810af7e6>] rebuild_sched_domains_locked+0x6e/0x3a8
> [ 2991.344562]  [<ffffffff810b0ec6>] rebuild_sched_domains+0x1c/0x2a
> [ 2991.344562]  [<ffffffff810b109b>] cpuset_hotplug_workfn+0x1c7/0x1d3
> [ 2991.344562]  [<ffffffff810b0ed9>] ? cpuset_hotplug_workfn+0x5/0x1d3
> [ 2991.344562]  [<ffffffff81058e07>] process_one_work+0x2d4/0x4d1
> [ 2991.344562]  [<ffffffff81058d3a>] ? process_one_work+0x207/0x4d1
> [ 2991.344562]  [<ffffffff8105964c>] worker_thread+0x2e7/0x3b5
> [ 2991.344562]  [<ffffffff81059365>] ? rescuer_thread+0x332/0x332
> [ 2991.344562]  [<ffffffff81061cdb>] kthread+0xb1/0xb9
> [ 2991.344562]  [<ffffffff81061c2a>] ? __init_kthread_worker+0x58/0x58
> [ 2991.344562]  [<ffffffff8154c1dc>] ret_from_fork+0x7c/0xb0
> [ 2991.344562]  [<ffffffff81061c2a>] ? __init_kthread_worker+0x58/0x58
> [ 2991.344562] bash            D ffffffff81a4aa80     0  2618   2612 0x10000000
> [ 2991.344562]  ffff8800379abb58 0000000000000002 0000000000000006 0000000000000c2c
> [ 2991.344562]  ffff880077fea140 ffff8800379abfd8 ffff8800379abfd8 00000000001d3c80
> [ 2991.344562]  ffff8800779ca5c0 ffff880077fea140 ffffffff81541fcf 0000000000000000
> [ 2991.344562] Call Trace:
> [ 2991.344562]  [<ffffffff81541fcf>] ? __mutex_lock_common+0x3d4/0x609
> [ 2991.344562]  [<ffffffff815437ba>] schedule+0x64/0x66
> [ 2991.344562]  [<ffffffff81543a39>] schedule_preempt_disabled+0x18/0x24
> [ 2991.344562]  [<ffffffff81541fcf>] __mutex_lock_common+0x3d4/0x609
> [ 2991.344562]  [<ffffffff81530078>] ? rcu_cpu_notify+0x2f5/0x86e
> [ 2991.344562]  [<ffffffff81530078>] ? rcu_cpu_notify+0x2f5/0x86e
> [ 2991.344562]  [<ffffffff815422ff>] mutex_lock_nested+0x3b/0x40
> [ 2991.344562]  [<ffffffff81530078>] rcu_cpu_notify+0x2f5/0x86e
> [ 2991.344562]  [<ffffffff81091c99>] ? __lock_is_held+0x32/0x53
> [ 2991.344562]  [<ffffffff81548912>] notifier_call_chain+0x6b/0x98
> [ 2991.344562]  [<ffffffff810671fd>] __raw_notifier_call_chain+0xe/0x10
> [ 2991.344562]  [<ffffffff8103cf64>] __cpu_notify+0x20/0x32
> [ 2991.344562]  [<ffffffff8103cf8d>] cpu_notify_nofail+0x17/0x36
> [ 2991.344562]  [<ffffffff815225de>] _cpu_down+0x154/0x259
> [ 2991.344562]  [<ffffffff81522710>] cpu_down+0x2d/0x3a
> [ 2991.344562]  [<ffffffff81526351>] store_online+0x4e/0xe7
> [ 2991.344562]  [<ffffffff8134d764>] dev_attr_store+0x20/0x22
> [ 2991.344562]  [<ffffffff811b3c5f>] sysfs_write_file+0x108/0x144
> [ 2991.344562]  [<ffffffff8114c5ef>] vfs_write+0xfd/0x158
> [ 2991.344562]  [<ffffffff8114c928>] SyS_write+0x5c/0x83
> [ 2991.344562]  [<ffffffff8154c494>] tracesys+0xdd/0xe2
>
> As well as held locks:
>
> [ 3034.728033] Showing all locks held in the system:
> [ 3034.728033] 1 lock held by rcu_preempt/10:
> [ 3034.728033]  #0:  (rcu_preempt_state.onoff_mutex){+.+...}, at: [<ffffffff810c9471>] rcu_gp_kthread+0x167/0x94b
> [ 3034.728033] 4 locks held by kworker/0:1/47:
> [ 3034.728033]  #0:  (events){.+.+.+}, at: [<ffffffff81058d3a>] process_one_work+0x207/0x4d1
> [ 3034.728033]  #1:  (cpuset_hotplug_work){+.+.+.}, at: [<ffffffff81058d3a>] process_one_work+0x207/0x4d1
> [ 3034.728033]  #2:  (cpuset_mutex){+.+.+.}, at: [<ffffffff810b0ec1>] rebuild_sched_domains+0x17/0x2a
> [ 3034.728033]  #3:  (cpu_hotplug.lock){+.+.+.}, at: [<ffffffff8103d11b>] get_online_cpus+0x3c/0x50
> [ 3034.728033] 1 lock held by mingetty/2563:
> [ 3034.728033]  #0:  (&ldata->atomic_read_lock){+.+...}, at: [<ffffffff8131e28a>] n_tty_read+0x252/0x7e8
> [ 3034.728033] 1 lock held by mingetty/2565:
> [ 3034.728033]  #0:  (&ldata->atomic_read_lock){+.+...}, at: [<ffffffff8131e28a>] n_tty_read+0x252/0x7e8
> [ 3034.728033] 1 lock held by mingetty/2569:
> [ 3034.728033]  #0:  (&ldata->atomic_read_lock){+.+...}, at: [<ffffffff8131e28a>] n_tty_read+0x252/0x7e8
> [ 3034.728033] 1 lock held by mingetty/2572:
> [ 3034.728033]  #0:  (&ldata->atomic_read_lock){+.+...}, at: [<ffffffff8131e28a>] n_tty_read+0x252/0x7e8
> [ 3034.728033] 1 lock held by mingetty/2575:
> [ 3034.728033]  #0:  (&ldata->atomic_read_lock){+.+...}, at: [<ffffffff8131e28a>] n_tty_read+0x252/0x7e8
> [ 3034.728033] 7 locks held by bash/2618:
> [ 3034.728033]  #0:  (sb_writers#5){.+.+.+}, at: [<ffffffff8114bc3f>] file_start_write+0x2a/0x2c
> [ 3034.728033]  #1:  (&buffer->mutex#2){+.+.+.}, at: [<ffffffff811b3b93>] sysfs_write_file+0x3c/0x144
> [ 3034.728033]  #2:  (s_active#54){.+.+.+}, at: [<ffffffff811b3c3e>] sysfs_write_file+0xe7/0x144
> [ 3034.728033]  #3:  (x86_cpu_hotplug_driver_mutex){+.+.+.}, at: [<ffffffff810217c2>] cpu_hotplug_driver_lock+0x17/0x19
> [ 3034.728033]  #4:  (cpu_add_remove_lock){+.+.+.}, at: [<ffffffff8103d196>] cpu_maps_update_begin+0x17/0x19
> [ 3034.728033]  #5:  (cpu_hotplug.lock){+.+.+.}, at: [<ffffffff8103cfd8>] cpu_hotplug_begin+0x2c/0x6d
> [ 3034.728033]  #6:  (rcu_preempt_state.onoff_mutex){+.+...}, at: [<ffffffff81530078>] rcu_cpu_notify+0x2f5/0x86e
> [ 3034.728033] 1 lock held by bash/2980:
> [ 3034.728033]  #0:  (&ldata->atomic_read_lock){+.+...}, at: [<ffffffff8131e28a>] n_tty_read+0x252/0x7e8
>
> Things looked a little weird. Also, this is a deadlock that lockdep did
> not catch. But what we have here does not look like a circular lock
> issue:
>
> Bash is blocked in rcu_cpu_notify():
>
> 1961		/* Exclude any attempts to start a new grace period. */
> 1962		mutex_lock(&rsp->onoff_mutex);
>
>
> kworker is blocked in get_online_cpus(), which makes sense as we are
> currently taking down a CPU.
>
> But rcu_preempt is not blocked on anything. It is simply sleeping in
> rcu_gp_kthread (really rcu_gp_init) here:
>
> 1453	#ifdef CONFIG_PROVE_RCU_DELAY
> 1454			if ((prandom_u32() % (rcu_num_nodes * 8)) == 0 &&
> 1455			    system_state == SYSTEM_RUNNING)
> 1456				schedule_timeout_uninterruptible(2);
> 1457	#endif /* #ifdef CONFIG_PROVE_RCU_DELAY */
>
> And it does this while holding the onoff_mutex that bash is waiting for.
>
> Doing a function trace, it showed me where it happened:
>
> [  125.940066] rcu_pree-10      3.... 28384115273: schedule_timeout_uninterruptible <-rcu_gp_kthread
> [...]
> [  125.940066] rcu_pree-10      3d..3 28384202439: sched_switch: prev_comm=rcu_preempt prev_pid=10 prev_prio=120 prev_state=D ==> next_comm=watchdog/3 next_pid=38 next_prio=120
>
> The watchdog ran, and then:
>
> [  125.940066] watchdog-38      3d..3 28384692863: sched_switch: prev_comm=watchdog/3 prev_pid=38 prev_prio=120 prev_state=P ==> next_comm=modprobe next_pid=2848 next_prio=118
>
> Not sure what modprobe was doing, but shortly after that:
>
> [  125.940066] modprobe-2848    3d..3 28385041749: sched_switch: prev_comm=modprobe prev_pid=2848 prev_prio=118 prev_state=R+ ==> next_comm=migration/3 next_pid=40 next_prio=0
>
> Where the migration thread took down the CPU:
>
> [  125.940066] migratio-40      3d..3 28389148276: sched_switch: prev_comm=migration/3 prev_pid=40 prev_prio=0 prev_state=P ==> next_comm=swapper/3 next_pid=0 next_prio=120
>
> which finally did:
>
> [  125.940066]   <idle>-0       3...1 28389282142: arch_cpu_idle_dead <-cpu_startup_entry
> [  125.940066]   <idle>-0       3...1 28389282548: native_play_dead <-arch_cpu_idle_dead
> [  125.940066]   <idle>-0       3...1 28389282924: play_dead_common <-native_play_dead
> [  125.940066]   <idle>-0       3...1 28389283468: idle_task_exit <-play_dead_common
> [  125.940066]   <idle>-0       3...1 28389284644: amd_e400_remove_cpu <-play_dead_common
>
>
> CPU 3 is now offline, the rcu_preempt thread that ran on CPU 3 is still
> doing a schedule_timeout_uninterruptible() and it registered it's
> timeout to the timer base for CPU 3. You would think that it would get
> migrated right? The issue here is that the timer migration happens at
> the CPU notifier for CPU_DEAD. The problem is that the rcu notifier for
> CPU_DOWN is blocked waiting for the onoff_mutex to be released, which is
> held by the thread that just put itself into a uninterruptible sleep,
> that wont wake up until the CPU_DEAD notifier of the timer
> infrastructure is called, which wont happen until the rcu notifier
> finishes. Here's our deadlock!

This commit breaks this deadlock cycle by substituting a shorter udelay()
for the previous schedule_timeout_uninterruptible(), while at the same
time increasing the probability of the delay.  This maintains the intensity
of the testing.

Reported-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Tested-by: Steven Rostedt <rostedt@goodmis.org>
koenkooi pushed a commit that referenced this pull request Jul 2, 2013
Michael L. Semon has been testing CRC patches on a 32 bit system and
been seeing assert failures in the directory code from xfs/080.
Thanks to Michael's heroic efforts with printk debugging, we found
that the problem was that the last free space being left in the
directory structure was too small to fit a unused tag structure and
it was being corrupted and attempting to log a region out of bounds.
Hence the assert failure looked something like:

.....
#5 calling xfs_dir2_data_log_unused() 36 32
#1 4092 4095 4096
#2 8182 8183 4096
XFS: Assertion failed: first <= last && last < BBTOB(bp->b_length), file: fs/xfs/xfs_trans_buf.c, line: 568

Where #1 showed the first region of the dup being logged (i.e. the
last 4 bytes of a directory buffer) and #2 shows the corrupt values
being calculated from the length of the dup entry which overflowed
the size of the buffer.

It turns out that the problem was not in the logging code, nor in
the freespace handling code. It is an initial condition bug that
only shows up on 32 bit systems. When a new buffer is initialised,
where's the freespace that is set up:

[  172.316249] calling xfs_dir2_leaf_addname() from xfs_dir_createname()
[  172.316346] #9 calling xfs_dir2_data_log_unused()
[  172.316351] #1 calling xfs_trans_log_buf() 60 63 4096
[  172.316353] #2 calling xfs_trans_log_buf() 4094 4095 4096

Note the offset of the first region being logged? It's 60 bytes into
the buffer. Once I saw that, I pretty much knew that the bug was
going to be caused by this.

Essentially, all direct entries are rounded to 8 bytes in length,
and all entries start with an 8 byte alignment. This means that we
can decode inplace as variables are naturally aligned. With the
directory data supposedly starting on a 8 byte boundary, and all
entries padded to 8 bytes, the minimum freespace in a directory
block is supposed to be 8 bytes, which is large enough to fit a
unused data entry structure (6 bytes in size). The fact we only have
4 bytes of free space indicates a directory data block alignment
problem.

And what do you know - there's an implicit hole in the directory
data block header for the CRC format, which means the header is 60
byte on 32 bit intel systems and 64 bytes on 64 bit systems. Needs
padding. And while looking at the structures, I found the same
problem in the attr leaf header. Fix them both.

Note that this only affects 32 bit systems with CRCs enabled.
Everything else is just fine. Note that CRC enabled filesystems created
before this fix on such systems will not be readable with this fix
applied.

Reported-by: Michael L. Semon <mlsemon35@gmail.com>
Debugged-by: Michael L. Semon <mlsemon35@gmail.com>
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Ben Myers <bpm@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>

(cherry picked from commit 8a1fd29)
koenkooi pushed a commit that referenced this pull request Sep 6, 2013
Michael L. Semon has been testing CRC patches on a 32 bit system and
been seeing assert failures in the directory code from xfs/080.
Thanks to Michael's heroic efforts with printk debugging, we found
that the problem was that the last free space being left in the
directory structure was too small to fit a unused tag structure and
it was being corrupted and attempting to log a region out of bounds.
Hence the assert failure looked something like:

.....
#5 calling xfs_dir2_data_log_unused() 36 32
#1 4092 4095 4096
#2 8182 8183 4096
XFS: Assertion failed: first <= last && last < BBTOB(bp->b_length), file: fs/xfs/xfs_trans_buf.c, line: 568

Where #1 showed the first region of the dup being logged (i.e. the
last 4 bytes of a directory buffer) and #2 shows the corrupt values
being calculated from the length of the dup entry which overflowed
the size of the buffer.

It turns out that the problem was not in the logging code, nor in
the freespace handling code. It is an initial condition bug that
only shows up on 32 bit systems. When a new buffer is initialised,
where's the freespace that is set up:

[  172.316249] calling xfs_dir2_leaf_addname() from xfs_dir_createname()
[  172.316346] #9 calling xfs_dir2_data_log_unused()
[  172.316351] #1 calling xfs_trans_log_buf() 60 63 4096
[  172.316353] #2 calling xfs_trans_log_buf() 4094 4095 4096

Note the offset of the first region being logged? It's 60 bytes into
the buffer. Once I saw that, I pretty much knew that the bug was
going to be caused by this.

Essentially, all direct entries are rounded to 8 bytes in length,
and all entries start with an 8 byte alignment. This means that we
can decode inplace as variables are naturally aligned. With the
directory data supposedly starting on a 8 byte boundary, and all
entries padded to 8 bytes, the minimum freespace in a directory
block is supposed to be 8 bytes, which is large enough to fit a
unused data entry structure (6 bytes in size). The fact we only have
4 bytes of free space indicates a directory data block alignment
problem.

And what do you know - there's an implicit hole in the directory
data block header for the CRC format, which means the header is 60
byte on 32 bit intel systems and 64 bytes on 64 bit systems. Needs
padding. And while looking at the structures, I found the same
problem in the attr leaf header. Fix them both.

Note that this only affects 32 bit systems with CRCs enabled.
Everything else is just fine. Note that CRC enabled filesystems created
before this fix on such systems will not be readable with this fix
applied.

Reported-by: Michael L. Semon <mlsemon35@gmail.com>
Debugged-by: Michael L. Semon <mlsemon35@gmail.com>
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Ben Myers <bpm@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
koenkooi pushed a commit that referenced this pull request Sep 6, 2013
This bug appear when a second PSC based driver appends an interrupt
routine to the FIFO controller shared interrupt (like spi-mpc512x-psc).
When reboot, uart_shutdown() remove the serial console interrupt handler
while spi-mpc512x-psc isr is still activate and cause the following kernel
panic:

The system is going down for reboot NOW!rpc (ttyPSC0) (Mon Jun 10 12:26:07 20
INIT: Sending processirq 40: nobody cared (try booting with the "irqpoll" option)
CPU: 0 PID: 0 Comm: swapper Not tainted 3.10.0-rc4-next-20130607-00001-ga0bceb3-dirty #5
Call Trace:
[cfff9f00] [c0007910] show_stack+0x48/0x150 (unreliable)
[cfff9f40] [c005ae60] __report_bad_irq.isra.6+0x34/0xe0
[cfff9f60] [c005b194] note_interrupt+0x214/0x26c
[cfff9f90] [c00590fc] handle_irq_event_percpu+0xd0/0x1bc
[cfff9fd0] [c005921c] handle_irq_event+0x34/0x54
[cfff9fe0] [c005b8f4] handle_level_irq+0x90/0xf4
[cfff9ff0] [c000cb98] call_handle_irq+0x18/0x28
[c050dd60] [c000575c] do_IRQ+0xcc/0x124
[c050dd90] [c000eb04] ret_from_except+0x0/0x14

Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
koenkooi pushed a commit that referenced this pull request Jul 6, 2017
MSS change on active QPs is not supported. Store new MSS
value for new QPs only. Remove code to modify MSS on the fly.
This also resolves a crash on QP modify to QP 0.

BUG: unable to handle kernel NULL pointer dereference at 0000000000000008
IP: i40iw_sc_qp_modify+0x22/0x280 [i40iw]
Oops: 0000 [#1] SMP KASAN
CPU: 2 PID: 1236 Comm: kworker/u16:4 Not tainted 4.12.0-rc1 #5
Hardware name: Gigabyte Technology Co., Ltd. To be filled by O.E.M./Q87M-D2H,
BIOS F7 01/17/2014
Workqueue: l2params i40iw_l2params_worker [i40iw]
task: ffff88070f5a9b40 task.stack: ffff88070f5a0000
RIP: 0010:i40iw_sc_qp_modify+0x22/0x280 [i40iw]
...
Call Trace:
i40iw_exec_cqp_cmd+0x2ce/0x410 [i40iw]
? _raw_spin_lock_irqsave+0x6f/0x80
? i40iw_process_cqp_cmd+0x1d/0x80 [i40iw]
i40iw_process_cqp_cmd+0x7c/0x80 [i40iw]
i40iw_handle_cqp_op+0x2f/0x200 [i40iw]
? trace_hardirqs_off+0xd/0x10
? _raw_spin_unlock_irqrestore+0x46/0x50
i40iw_hw_modify_qp+0x5e/0x90 [i40iw]
i40iw_qp_mss_modify+0x52/0x60 [i40iw]
i40iw_change_l2params+0x145/0x160 [i40iw]
i40iw_l2params_worker+0x1f/0x40 [i40iw]
process_one_work+0x1f5/0x650
? process_one_work+0x161/0x650
worker_thread+0x48/0x3b0
kthread+0x112/0x150
? process_one_work+0x650/0x650
? kthread_create_on_node+0x40/0x40
ret_from_fork+0x2e/0x40
Code: 2e 0f 1f 84 00 00 00 00 00 55 48 89 e5 41 56 41 55 41 89 cd 41 54 49 89 fc
53 48 89 f3 48 89 d6 48 83 ec 08 48 8b 87 10 01 00 00 <48> 8b 40 08 4c 8b b0 40 04
00 00 4c 89 f7 e8 1b e5 ff ff 48 85
RIP: i40iw_sc_qp_modify+0x22/0x280 [i40iw] RSP: ffff88070f5a7c28
CR2: 0000000000000008
---[ end trace 77a405931e296060 ]---

Reported-by: Stefan Assmann <sassmann@redhat.com>
Signed-off-by: Shiraz Saleem <shiraz.saleem@intel.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
koenkooi pushed a commit that referenced this pull request Jul 6, 2017
A NULL-pointer dereference bug in gadgetfs was uncovered by syzkaller:

> kasan: GPF could be caused by NULL-ptr deref or user memory access
> general protection fault: 0000 [#1] SMP KASAN
> Dumping ftrace buffer:
>    (ftrace buffer empty)
> Modules linked in:
> CPU: 2 PID: 4820 Comm: syz-executor0 Not tainted 4.12.0-rc4+ #5
> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
> task: ffff880039542dc0 task.stack: ffff88003bdd0000
> RIP: 0010:__list_del_entry_valid+0x7e/0x170 lib/list_debug.c:51
> RSP: 0018:ffff88003bdd6e50 EFLAGS: 00010246
> RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000010000
> RDX: 0000000000000000 RSI: ffffffff86504948 RDI: ffffffff86504950
> RBP: ffff88003bdd6e68 R08: ffff880039542dc0 R09: ffffffff8778ce00
> R10: ffff88003bdd6e68 R11: dffffc0000000000 R12: 0000000000000000
> R13: dffffc0000000000 R14: 1ffff100077badd2 R15: ffffffff864d2e40
> FS:  0000000000000000(0000) GS:ffff88006dc00000(0000) knlGS:0000000000000000
> CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
> CR2: 000000002014aff9 CR3: 0000000006022000 CR4: 00000000000006e0
> Call Trace:
>  __list_del_entry include/linux/list.h:116 [inline]
>  list_del include/linux/list.h:124 [inline]
>  usb_gadget_unregister_driver+0x166/0x4c0 drivers/usb/gadget/udc/core.c:1387
>  dev_release+0x80/0x160 drivers/usb/gadget/legacy/inode.c:1187
>  __fput+0x332/0x7f0 fs/file_table.c:209
>  ____fput+0x15/0x20 fs/file_table.c:245
>  task_work_run+0x19b/0x270 kernel/task_work.c:116
>  exit_task_work include/linux/task_work.h:21 [inline]
>  do_exit+0x18a3/0x2820 kernel/exit.c:878
>  do_group_exit+0x149/0x420 kernel/exit.c:982
>  get_signal+0x77f/0x1780 kernel/signal.c:2318
>  do_signal+0xd2/0x2130 arch/x86/kernel/signal.c:808
>  exit_to_usermode_loop+0x1a7/0x240 arch/x86/entry/common.c:157
>  prepare_exit_to_usermode arch/x86/entry/common.c:194 [inline]
>  syscall_return_slowpath+0x3ba/0x410 arch/x86/entry/common.c:263
>  entry_SYSCALL_64_fastpath+0xbc/0xbe
> RIP: 0033:0x4461f9
> RSP: 002b:00007fdac2b1ecf8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca
> RAX: fffffffffffffe00 RBX: 00000000007080c8 RCX: 00000000004461f9
> RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00000000007080c8
> RBP: 00000000007080a8 R08: 0000000000000000 R09: 0000000000000000
> R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
> R13: 0000000000000000 R14: 00007fdac2b1f9c0 R15: 00007fdac2b1f700
> Code: 00 00 00 00 ad de 49 39 c4 74 6a 48 b8 00 02 00 00 00 00 ad de
> 48 89 da 48 39 c3 74 74 48 c1 ea 03 48 b8 00 00 00 00 00 fc ff df <80>
> 3c 02 00 0f 85 92 00 00 00 48 8b 13 48 39 f2 75 66 49 8d 7c
> RIP: __list_del_entry_valid+0x7e/0x170 lib/list_debug.c:51 RSP: ffff88003bdd6e50
> ---[ end trace 30e94b1eec4831c8 ]---
> Kernel panic - not syncing: Fatal exception

The bug was caused by dev_release() failing to turn off its
gadget_registered flag after unregistering the gadget driver.  As a
result, when a later user closed the device file before writing a
valid set of descriptors, dev_release() thought the gadget had been
registered and tried to unregister it, even though it had not been.
This led to the NULL pointer dereference.

The fix is simple: turn off the flag when the gadget is unregistered.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Reported-and-tested-by: Andrey Konovalov <andreyknvl@google.com>
CC: <stable@vger.kernel.org>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
koenkooi pushed a commit that referenced this pull request Jul 6, 2017
Fix the following kernel bug:

kernel BUG at drivers/iommu/intel-iommu.c:3260!
invalid opcode: 0000 [#5] PREEMPT SMP
Hardware name: Intel Corp. Harcuvar/Server, BIOS HAVLCRB0.X64.0013.D39.1608311820 08/31/2016
task: ffff880175389950 ti: ffff880176bec000 task.ti: ffff880176bec000
RIP: 0010:[<ffffffff8150a83b>]  [<ffffffff8150a83b>] intel_unmap+0x25b/0x260
RSP: 0018:ffff880176bef5e8  EFLAGS: 00010296
RAX: 0000000000000024 RBX: ffff8800773c7c88 RCX: 000000000000ce04
RDX: 0000000080000000 RSI: 0000000000000000 RDI: 0000000000000009
RBP: ffff880176bef638 R08: 0000000000000010 R09: 0000000000000004
R10: ffff880175389c78 R11: 0000000000000a4f R12: ffff8800773c7868
R13: 00000000ffffac88 R14: ffff8800773c7818 R15: 0000000000000001
FS:  00007fef21258700(0000) GS:ffff88017b5c0000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000000066d6d8 CR3: 000000007118c000 CR4: 00000000003406e0
Stack:
 00000000ffffac88 ffffffff8199867f ffff880176bef5f8 ffff880100000030
 ffff880176bef668 ffff8800773c7c88 ffff880178288098 ffff8800772c0010
 ffff8800773c7818 0000000000000001 ffff880176bef648 ffffffff8150a86e
Call Trace:
 [<ffffffff8199867f>] ? printk+0x46/0x48
 [<ffffffff8150a86e>] intel_unmap_page+0xe/0x10
 [<ffffffffa039d99b>] ismt_access+0x27b/0x8fa [i2c_ismt]
 [<ffffffff81554420>] ? __pm_runtime_suspend+0xa0/0xa0
 [<ffffffff815544a0>] ? pm_suspend_timer_fn+0x80/0x80
 [<ffffffff81554420>] ? __pm_runtime_suspend+0xa0/0xa0
 [<ffffffff815544a0>] ? pm_suspend_timer_fn+0x80/0x80
 [<ffffffff8143dfd0>] ? pci_bus_read_dev_vendor_id+0xf0/0xf0
 [<ffffffff8172b36c>] i2c_smbus_xfer+0xec/0x4b0
 [<ffffffff810aa4d5>] ? vprintk_emit+0x345/0x530
 [<ffffffffa038936b>] i2cdev_ioctl_smbus+0x12b/0x240 [i2c_dev]
 [<ffffffff810aa829>] ? vprintk_default+0x29/0x40
 [<ffffffffa0389b33>] i2cdev_ioctl+0x63/0x1ec [i2c_dev]
 [<ffffffff811b04c8>] do_vfs_ioctl+0x328/0x5d0
 [<ffffffff8119d8ec>] ? vfs_write+0x11c/0x190
 [<ffffffff8109d449>] ? rt_up_read+0x19/0x20
 [<ffffffff811b07f1>] SyS_ioctl+0x81/0xa0
 [<ffffffff819a351b>] system_call_fastpath+0x16/0x6e

This happen When run "i2cdetect -y 0" detect SMBus iSMT adapter.

After finished I2C block read/write, when unmap the data buffer,
a wrong device address was pass to dma_unmap_single().

To fix this, give dma_unmap_single() the "dev" parameter, just like
what dma_map_single() does, then unmap can find the right devices.

Fixes: 13f35ac ("i2c: Adding support for Intel iSMT SMBus 2.0 host controller")
Signed-off-by: Liwei Song <liwei.song@windriver.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Signed-off-by: Wolfram Sang <wsa@the-dreams.de>
koenkooi pushed a commit that referenced this pull request Nov 4, 2017
commit ab31fd0 upstream.

v4.10 commit 6f2ce1c ("scsi: zfcp: fix rport unblock race with LUN
recovery") extended accessing parent pointer fields of struct
zfcp_erp_action for tracing.  If an erp_action has never been enqueued
before, these parent pointer fields are uninitialized and NULL. Examples
are zfcp objects freshly added to the parent object's children list,
before enqueueing their first recovery subsequently. In
zfcp_erp_try_rport_unblock(), we iterate such list. Accessing erp_action
fields can cause a NULL pointer dereference.  Since the kernel can read
from lowcore on s390, it does not immediately cause a kernel page
fault. Instead it can cause hangs on trying to acquire the wrong
erp_action->adapter->dbf->rec_lock in zfcp_dbf_rec_action_lvl()
                      ^bogus^
while holding already other locks with IRQs disabled.

Real life example from attaching lots of LUNs in parallel on many CPUs:

crash> bt 17723
PID: 17723  TASK: ...               CPU: 25  COMMAND: "zfcperp0.0.1800"
 LOWCORE INFO:
  -psw      : 0x0404300180000000 0x000000000038e424
  -function : _raw_spin_lock_wait_flags at 38e424
...
 #0 [fdde8fc90] zfcp_dbf_rec_action_lvl at 3e0004e9862 [zfcp]
 #1 [fdde8fce8] zfcp_erp_try_rport_unblock at 3e0004dfddc [zfcp]
 #2 [fdde8fd38] zfcp_erp_strategy at 3e0004e0234 [zfcp]
 #3 [fdde8fda8] zfcp_erp_thread at 3e0004e0a12 [zfcp]
 #4 [fdde8fe60] kthread at 173550
 #5 [fdde8feb8] kernel_thread_starter at 10add2

zfcp_adapter
 zfcp_port
  zfcp_unit <address>, 0x404040d600000000
  scsi_device NULL, returning early!
zfcp_scsi_dev.status = 0x40000000
0x40000000 ZFCP_STATUS_COMMON_RUNNING

crash> zfcp_unit <address>
struct zfcp_unit {
  erp_action = {
    adapter = 0x0,
    port = 0x0,
    unit = 0x0,
  },
}

zfcp_erp_action is always fully embedded into its container object. Such
container object is never moved in its object tree (only add or delete).
Hence, erp_action parent pointers can never change.

To fix the issue, initialize the erp_action parent pointers before
adding the erp_action container to any list and thus before it becomes
accessible from outside of its initializing function.

In order to also close the time window between zfcp_erp_setup_act()
memsetting the entire erp_action to zero and setting the parent pointers
again, drop the memset and instead explicitly initialize individually
all erp_action fields except for parent pointers. To be extra careful
not to introduce any other unintended side effect, even keep zeroing the
erp_action fields for list and timer. Also double-check with
WARN_ON_ONCE that erp_action parent pointers never change, so we get to
know when we would deviate from previous behavior.

Signed-off-by: Steffen Maier <maier@linux.vnet.ibm.com>
Fixes: 6f2ce1c ("scsi: zfcp: fix rport unblock race with LUN recovery")
Reviewed-by: Benjamin Block <bblock@linux.vnet.ibm.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
koenkooi pushed a commit that referenced this pull request May 29, 2018
syzbot caught an infinite recursion in nsh_gso_segment().

Problem here is that we need to make sure the NSH header is of
reasonable length.

BUG: MAX_LOCK_DEPTH too low!
turning off the locking correctness validator.
depth: 48  max: 48!
48 locks held by syz-executor0/10189:
 #0:         (ptrval) (rcu_read_lock_bh){....}, at: __dev_queue_xmit+0x30f/0x34c0 net/core/dev.c:3517
 #1:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #1:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #2:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #2:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #3:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #3:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #4:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #4:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #5:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #5:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #6:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #6:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #7:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #7:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #8:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #8:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #9:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #9:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 torvalds#10:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 torvalds#10:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 torvalds#11:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 torvalds#11:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 torvalds#12:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 torvalds#12:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 torvalds#13:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 torvalds#13:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 torvalds#14:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 torvalds#14:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 torvalds#15:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 torvalds#15:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 torvalds#16:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 torvalds#16:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 torvalds#17:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 torvalds#17:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 torvalds#18:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 torvalds#18:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 torvalds#19:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 torvalds#19:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 torvalds#20:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 torvalds#20:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 torvalds#21:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 torvalds#21:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 torvalds#22:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 torvalds#22:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 torvalds#23:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 torvalds#23:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 torvalds#24:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 torvalds#24:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 torvalds#25:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 torvalds#25:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 torvalds#26:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 torvalds#26:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 torvalds#27:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 torvalds#27:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 torvalds#28:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 torvalds#28:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 torvalds#29:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 torvalds#29:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 torvalds#30:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 torvalds#30:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 torvalds#31:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 torvalds#31:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
dccp_close: ABORT with 65423 bytes unread
 torvalds#32:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 torvalds#32:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 torvalds#33:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 torvalds#33:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 torvalds#34:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 torvalds#34:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 torvalds#35:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 torvalds#35:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 torvalds#36:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 torvalds#36:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 torvalds#37:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 torvalds#37:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 torvalds#38:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 torvalds#38:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 torvalds#39:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 torvalds#39:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 torvalds#40:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 torvalds#40:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 torvalds#41:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 torvalds#41:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 torvalds#42:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 torvalds#42:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 torvalds#43:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 torvalds#43:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 torvalds#44:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 torvalds#44:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 torvalds#45:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 torvalds#45:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 torvalds#46:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 torvalds#46:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 torvalds#47:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 torvalds#47:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
INFO: lockdep is turned off.
CPU: 1 PID: 10189 Comm: syz-executor0 Not tainted 4.17.0-rc2+ torvalds#26
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1b9/0x294 lib/dump_stack.c:113
 __lock_acquire+0x1788/0x5140 kernel/locking/lockdep.c:3449
 lock_acquire+0x1dc/0x520 kernel/locking/lockdep.c:3920
 rcu_lock_acquire include/linux/rcupdate.h:246 [inline]
 rcu_read_lock include/linux/rcupdate.h:632 [inline]
 skb_mac_gso_segment+0x25b/0x720 net/core/dev.c:2789
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 __skb_gso_segment+0x3bb/0x870 net/core/dev.c:2865
 skb_gso_segment include/linux/netdevice.h:4025 [inline]
 validate_xmit_skb+0x54d/0xd90 net/core/dev.c:3118
 validate_xmit_skb_list+0xbf/0x120 net/core/dev.c:3168
 sch_direct_xmit+0x354/0x11e0 net/sched/sch_generic.c:312
 qdisc_restart net/sched/sch_generic.c:399 [inline]
 __qdisc_run+0x741/0x1af0 net/sched/sch_generic.c:410
 __dev_xmit_skb net/core/dev.c:3243 [inline]
 __dev_queue_xmit+0x28ea/0x34c0 net/core/dev.c:3551
 dev_queue_xmit+0x17/0x20 net/core/dev.c:3616
 packet_snd net/packet/af_packet.c:2951 [inline]
 packet_sendmsg+0x40f8/0x6070 net/packet/af_packet.c:2976
 sock_sendmsg_nosec net/socket.c:629 [inline]
 sock_sendmsg+0xd5/0x120 net/socket.c:639
 __sys_sendto+0x3d7/0x670 net/socket.c:1789
 __do_sys_sendto net/socket.c:1801 [inline]
 __se_sys_sendto net/socket.c:1797 [inline]
 __x64_sys_sendto+0xe1/0x1a0 net/socket.c:1797
 do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Fixes: c411ed8 ("nsh: add GSO support")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Jiri Benc <jbenc@redhat.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Acked-by: Jiri Benc <jbenc@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
koenkooi pushed a commit that referenced this pull request May 29, 2018
stub_probe() calls put_busid_priv() in an error path when device isn't
found in the busid_table. Fix it by making put_busid_priv() safe to be
called with null struct bus_id_priv pointer.

This problem happens when "usbip bind" is run without loading usbip_host
driver and then running modprobe. The first failed bind attempt unbinds
the device from the original driver and when usbip_host is modprobed,
stub_probe() runs and doesn't find the device in its busid table and calls
put_busid_priv(0 with null bus_id_priv pointer.

usbip-host 3-10.2: 3-10.2 is not in match_busid table...  skip!

[  367.359679] =====================================
[  367.359681] WARNING: bad unlock balance detected!
[  367.359683] 4.17.0-rc4+ #5 Not tainted
[  367.359685] -------------------------------------
[  367.359688] modprobe/2768 is trying to release lock (
[  367.359689]
==================================================================
[  367.359696] BUG: KASAN: null-ptr-deref in print_unlock_imbalance_bug+0x99/0x110
[  367.359699] Read of size 8 at addr 0000000000000058 by task modprobe/2768

[  367.359705] CPU: 4 PID: 2768 Comm: modprobe Not tainted 4.17.0-rc4+ #5

Fixes: 2207655 ("usbip: usbip_host: fix NULL-ptr deref and use-after-free errors") in usb-linus
Signed-off-by: Shuah Khan (Samsung OSG) <shuah@kernel.org>
Cc: stable <stable@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
koenkooi pushed a commit that referenced this pull request Jun 6, 2018
[ Upstream commit af50e4b ]

syzbot caught an infinite recursion in nsh_gso_segment().

Problem here is that we need to make sure the NSH header is of
reasonable length.

BUG: MAX_LOCK_DEPTH too low!
turning off the locking correctness validator.
depth: 48  max: 48!
48 locks held by syz-executor0/10189:
 #0:         (ptrval) (rcu_read_lock_bh){....}, at: __dev_queue_xmit+0x30f/0x34c0 net/core/dev.c:3517
 #1:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #1:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #2:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #2:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #3:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #3:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #4:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #4:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #5:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #5:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #6:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #6:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #7:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #7:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #8:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #8:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 #9:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 #9:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 torvalds#10:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 torvalds#10:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 torvalds#11:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 torvalds#11:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 torvalds#12:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 torvalds#12:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 torvalds#13:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 torvalds#13:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 torvalds#14:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 torvalds#14:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 torvalds#15:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 torvalds#15:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 torvalds#16:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 torvalds#16:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 torvalds#17:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 torvalds#17:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 torvalds#18:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 torvalds#18:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 torvalds#19:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 torvalds#19:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 torvalds#20:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 torvalds#20:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 torvalds#21:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 torvalds#21:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 torvalds#22:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 torvalds#22:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 torvalds#23:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 torvalds#23:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 torvalds#24:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 torvalds#24:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 torvalds#25:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 torvalds#25:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 torvalds#26:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 torvalds#26:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 torvalds#27:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 torvalds#27:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 torvalds#28:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 torvalds#28:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 torvalds#29:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 torvalds#29:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 torvalds#30:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 torvalds#30:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 torvalds#31:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 torvalds#31:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
dccp_close: ABORT with 65423 bytes unread
 torvalds#32:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 torvalds#32:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 torvalds#33:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 torvalds#33:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 torvalds#34:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 torvalds#34:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 torvalds#35:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 torvalds#35:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 torvalds#36:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 torvalds#36:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 torvalds#37:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 torvalds#37:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 torvalds#38:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 torvalds#38:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 torvalds#39:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 torvalds#39:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 torvalds#40:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 torvalds#40:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 torvalds#41:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 torvalds#41:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 torvalds#42:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 torvalds#42:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 torvalds#43:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 torvalds#43:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 torvalds#44:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 torvalds#44:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 torvalds#45:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 torvalds#45:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 torvalds#46:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 torvalds#46:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
 torvalds#47:         (ptrval) (rcu_read_lock){....}, at: __skb_pull include/linux/skbuff.h:2080 [inline]
 torvalds#47:         (ptrval) (rcu_read_lock){....}, at: skb_mac_gso_segment+0x221/0x720 net/core/dev.c:2787
INFO: lockdep is turned off.
CPU: 1 PID: 10189 Comm: syz-executor0 Not tainted 4.17.0-rc2+ torvalds#26
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1b9/0x294 lib/dump_stack.c:113
 __lock_acquire+0x1788/0x5140 kernel/locking/lockdep.c:3449
 lock_acquire+0x1dc/0x520 kernel/locking/lockdep.c:3920
 rcu_lock_acquire include/linux/rcupdate.h:246 [inline]
 rcu_read_lock include/linux/rcupdate.h:632 [inline]
 skb_mac_gso_segment+0x25b/0x720 net/core/dev.c:2789
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 nsh_gso_segment+0x405/0xb60 net/nsh/nsh.c:107
 skb_mac_gso_segment+0x3ad/0x720 net/core/dev.c:2792
 __skb_gso_segment+0x3bb/0x870 net/core/dev.c:2865
 skb_gso_segment include/linux/netdevice.h:4025 [inline]
 validate_xmit_skb+0x54d/0xd90 net/core/dev.c:3118
 validate_xmit_skb_list+0xbf/0x120 net/core/dev.c:3168
 sch_direct_xmit+0x354/0x11e0 net/sched/sch_generic.c:312
 qdisc_restart net/sched/sch_generic.c:399 [inline]
 __qdisc_run+0x741/0x1af0 net/sched/sch_generic.c:410
 __dev_xmit_skb net/core/dev.c:3243 [inline]
 __dev_queue_xmit+0x28ea/0x34c0 net/core/dev.c:3551
 dev_queue_xmit+0x17/0x20 net/core/dev.c:3616
 packet_snd net/packet/af_packet.c:2951 [inline]
 packet_sendmsg+0x40f8/0x6070 net/packet/af_packet.c:2976
 sock_sendmsg_nosec net/socket.c:629 [inline]
 sock_sendmsg+0xd5/0x120 net/socket.c:639
 __sys_sendto+0x3d7/0x670 net/socket.c:1789
 __do_sys_sendto net/socket.c:1801 [inline]
 __se_sys_sendto net/socket.c:1797 [inline]
 __x64_sys_sendto+0xe1/0x1a0 net/socket.c:1797
 do_syscall_64+0x1b1/0x800 arch/x86/entry/common.c:287
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Fixes: c411ed8 ("nsh: add GSO support")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Jiri Benc <jbenc@redhat.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Acked-by: Jiri Benc <jbenc@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
koenkooi pushed a commit that referenced this pull request Jun 6, 2018
commit c171654 upstream.

stub_probe() calls put_busid_priv() in an error path when device isn't
found in the busid_table. Fix it by making put_busid_priv() safe to be
called with null struct bus_id_priv pointer.

This problem happens when "usbip bind" is run without loading usbip_host
driver and then running modprobe. The first failed bind attempt unbinds
the device from the original driver and when usbip_host is modprobed,
stub_probe() runs and doesn't find the device in its busid table and calls
put_busid_priv(0 with null bus_id_priv pointer.

usbip-host 3-10.2: 3-10.2 is not in match_busid table...  skip!

[  367.359679] =====================================
[  367.359681] WARNING: bad unlock balance detected!
[  367.359683] 4.17.0-rc4+ #5 Not tainted
[  367.359685] -------------------------------------
[  367.359688] modprobe/2768 is trying to release lock (
[  367.359689]
==================================================================
[  367.359696] BUG: KASAN: null-ptr-deref in print_unlock_imbalance_bug+0x99/0x110
[  367.359699] Read of size 8 at addr 0000000000000058 by task modprobe/2768

[  367.359705] CPU: 4 PID: 2768 Comm: modprobe Not tainted 4.17.0-rc4+ #5

Fixes: 2207655 ("usbip: usbip_host: fix NULL-ptr deref and use-after-free errors") in usb-linus
Signed-off-by: Shuah Khan (Samsung OSG) <shuah@kernel.org>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
koenkooi pushed a commit that referenced this pull request Jun 6, 2018
[ Upstream commit fca3234 ]

Executing command 'perf stat -T -- ls' dumps core on x86 and s390.

Here is the call back chain (done on x86):

 # gdb ./perf
 ....
 (gdb) r stat -T -- ls
...
Program received signal SIGSEGV, Segmentation fault.
0x00007ffff56d1963 in vasprintf () from /lib64/libc.so.6
(gdb) where
 #0  0x00007ffff56d1963 in vasprintf () from /lib64/libc.so.6
 #1  0x00007ffff56ae484 in asprintf () from /lib64/libc.so.6
 #2  0x00000000004f1982 in __parse_events_add_pmu (parse_state=0x7fffffffd580,
    list=0xbfb970, name=0xbf3ef0 "cpu",
    head_config=0xbfb930, auto_merge_stats=false) at util/parse-events.c:1233
 #3  0x00000000004f1c8e in parse_events_add_pmu (parse_state=0x7fffffffd580,
    list=0xbfb970, name=0xbf3ef0 "cpu",
    head_config=0xbfb930) at util/parse-events.c:1288
 #4  0x0000000000537ce3 in parse_events_parse (_parse_state=0x7fffffffd580,
    scanner=0xbf4210) at util/parse-events.y:234
 #5  0x00000000004f2c7a in parse_events__scanner (str=0x6b66c0
    "task-clock,{instructions,cycles,cpu/cycles-t/,cpu/tx-start/}",
    parse_state=0x7fffffffd580, start_token=258) at util/parse-events.c:1673
 #6  0x00000000004f2e23 in parse_events (evlist=0xbe9990, str=0x6b66c0
    "task-clock,{instructions,cycles,cpu/cycles-t/,cpu/tx-start/}", err=0x0)
    at util/parse-events.c:1713
 #7  0x000000000044e137 in add_default_attributes () at builtin-stat.c:2281
 #8  0x000000000044f7b5 in cmd_stat (argc=1, argv=0x7fffffffe3b0) at
    builtin-stat.c:2828
 #9  0x00000000004c8b0f in run_builtin (p=0xab01a0 <commands+288>, argc=4,
    argv=0x7fffffffe3b0) at perf.c:297
 torvalds#10 0x00000000004c8d7c in handle_internal_command (argc=4,
    argv=0x7fffffffe3b0) at perf.c:349
 torvalds#11 0x00000000004c8ece in run_argv (argcp=0x7fffffffe20c,
   argv=0x7fffffffe200) at perf.c:393
 torvalds#12 0x00000000004c929c in main (argc=4, argv=0x7fffffffe3b0) at perf.c:537
(gdb)

It turns out that a NULL pointer is referenced. Here are the
function calls:

  ...
  cmd_stat()
  +---> add_default_attributes()
	+---> parse_events(evsel_list, transaction_attrs, NULL);
	             3rd parameter set to NULL

Function parse_events(xx, xx, struct parse_events_error *err) dives
into a bison generated scanner and creates
parser state information for it first:

   struct parse_events_state parse_state = {
                .list   = LIST_HEAD_INIT(parse_state.list),
                .idx    = evlist->nr_entries,
                .error  = err,   <--- NULL POINTER !!!
                .evlist = evlist,
        };

Now various functions inside the bison scanner are called to end up in
__parse_events_add_pmu(struct parse_events_state *parse_state, ..) with
first parameter being a pointer to above structure definition.

Now the PMU event name is not found (because being executed in a VM) and
this function tries to create an error message with

   asprintf(&parse_state->error.str, ....)

which references a NULL pointer and dumps core.

Fix this by providing a pointer to the necessary error information
instead of NULL. Technically only the else part is needed to avoid the
core dump, just lets be safe...

Signed-off-by: Thomas Richter <tmricht@linux.vnet.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Hendrik Brueckner <brueckner@linux.vnet.ibm.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Link: http://lkml.kernel.org/r/20180308145735.64717-1-tmricht@linux.vnet.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
koenkooi pushed a commit that referenced this pull request Jun 6, 2018
[ Upstream commit 2bbea6e ]

when mounting an ISO filesystem sometimes (very rarely)
the system hangs because of a race condition between two tasks.

PID: 6766   TASK: ffff88007b2a6dd0  CPU: 0   COMMAND: "mount"
 #0 [ffff880078447ae0] __schedule at ffffffff8168d605
 #1 [ffff880078447b48] schedule_preempt_disabled at ffffffff8168ed49
 #2 [ffff880078447b58] __mutex_lock_slowpath at ffffffff8168c995
 #3 [ffff880078447bb8] mutex_lock at ffffffff8168bdef
 #4 [ffff880078447bd0] sr_block_ioctl at ffffffffa00b6818 [sr_mod]
 #5 [ffff880078447c10] blkdev_ioctl at ffffffff812fea50
 #6 [ffff880078447c70] ioctl_by_bdev at ffffffff8123a8b3
 #7 [ffff880078447c90] isofs_fill_super at ffffffffa04fb1e1 [isofs]
 #8 [ffff880078447da8] mount_bdev at ffffffff81202570
 #9 [ffff880078447e18] isofs_mount at ffffffffa04f9828 [isofs]
torvalds#10 [ffff880078447e28] mount_fs at ffffffff81202d09
torvalds#11 [ffff880078447e70] vfs_kern_mount at ffffffff8121ea8f
torvalds#12 [ffff880078447ea8] do_mount at ffffffff81220fee
torvalds#13 [ffff880078447f28] sys_mount at ffffffff812218d6
torvalds#14 [ffff880078447f80] system_call_fastpath at ffffffff81698c49
    RIP: 00007fd9ea914e9a  RSP: 00007ffd5d9bf648  RFLAGS: 00010246
    RAX: 00000000000000a5  RBX: ffffffff81698c49  RCX: 0000000000000010
    RDX: 00007fd9ec2bc210  RSI: 00007fd9ec2bc290  RDI: 00007fd9ec2bcf30
    RBP: 0000000000000000   R8: 0000000000000000   R9: 0000000000000010
    R10: 00000000c0ed0001  R11: 0000000000000206  R12: 00007fd9ec2bc040
    R13: 00007fd9eb6b2380  R14: 00007fd9ec2bc210  R15: 00007fd9ec2bcf30
    ORIG_RAX: 00000000000000a5  CS: 0033  SS: 002b

This task was trying to mount the cdrom.  It allocated and configured a
super_block struct and owned the write-lock for the super_block->s_umount
rwsem. While exclusively owning the s_umount lock, it called
sr_block_ioctl and waited to acquire the global sr_mutex lock.

PID: 6785   TASK: ffff880078720fb0  CPU: 0   COMMAND: "systemd-udevd"
 #0 [ffff880078417898] __schedule at ffffffff8168d605
 #1 [ffff880078417900] schedule at ffffffff8168dc59
 #2 [ffff880078417910] rwsem_down_read_failed at ffffffff8168f605
 #3 [ffff880078417980] call_rwsem_down_read_failed at ffffffff81328838
 #4 [ffff8800784179d0] down_read at ffffffff8168cde0
 #5 [ffff8800784179e8] get_super at ffffffff81201cc7
 #6 [ffff880078417a10] __invalidate_device at ffffffff8123a8de
 #7 [ffff880078417a40] flush_disk at ffffffff8123a94b
 #8 [ffff880078417a88] check_disk_change at ffffffff8123ab50
 #9 [ffff880078417ab0] cdrom_open at ffffffffa00a29e1 [cdrom]
torvalds#10 [ffff880078417b68] sr_block_open at ffffffffa00b6f9b [sr_mod]
torvalds#11 [ffff880078417b98] __blkdev_get at ffffffff8123ba86
torvalds#12 [ffff880078417bf0] blkdev_get at ffffffff8123bd65
torvalds#13 [ffff880078417c78] blkdev_open at ffffffff8123bf9b
torvalds#14 [ffff880078417c90] do_dentry_open at ffffffff811fc7f7
torvalds#15 [ffff880078417cd8] vfs_open at ffffffff811fc9cf
torvalds#16 [ffff880078417d00] do_last at ffffffff8120d53d
torvalds#17 [ffff880078417db0] path_openat at ffffffff8120e6b2
torvalds#18 [ffff880078417e48] do_filp_open at ffffffff8121082b
torvalds#19 [ffff880078417f18] do_sys_open at ffffffff811fdd33
torvalds#20 [ffff880078417f70] sys_open at ffffffff811fde4e
torvalds#21 [ffff880078417f80] system_call_fastpath at ffffffff81698c49
    RIP: 00007f29438b0c20  RSP: 00007ffc76624b78  RFLAGS: 00010246
    RAX: 0000000000000002  RBX: ffffffff81698c49  RCX: 0000000000000000
    RDX: 00007f2944a5fa70  RSI: 00000000000a0800  RDI: 00007f2944a5fa70
    RBP: 00007f2944a5f540   R8: 0000000000000000   R9: 0000000000000020
    R10: 00007f2943614c40  R11: 0000000000000246  R12: ffffffff811fde4e
    R13: ffff880078417f78  R14: 000000000000000c  R15: 00007f2944a4b010
    ORIG_RAX: 0000000000000002  CS: 0033  SS: 002b

This task tried to open the cdrom device, the sr_block_open function
acquired the global sr_mutex lock. The call to check_disk_change()
then saw an event flag indicating a possible media change and tried
to flush any cached data for the device.
As part of the flush, it tried to acquire the super_block->s_umount
lock associated with the cdrom device.
This was the same super_block as created and locked by the previous task.

The first task acquires the s_umount lock and then the sr_mutex_lock;
the second task acquires the sr_mutex_lock and then the s_umount lock.

This patch fixes the issue by moving check_disk_change() out of
cdrom_open() and let the caller take care of it.

Signed-off-by: Maurizio Lombardi <mlombard@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
koenkooi pushed a commit that referenced this pull request Jul 8, 2018
commit b23220f upstream.

The balloon.page field is used for two different purposes if batching is
on or off. If batching is on, the field point to the page which is used
to communicate with with the hypervisor. If it is off, balloon.page
points to the page that is about to be (un)locked.

Unfortunately, this dual-purpose of the field introduced a bug: when the
balloon is popped (e.g., when the machine is reset or the balloon driver
is explicitly removed), the balloon driver frees, unconditionally, the
page that is held in balloon.page.  As a result, if batching is
disabled, this leads to double freeing the last page that is sent to the
hypervisor.

The following error occurs during rmmod when kernel checkers are on, and
the balloon is not empty:

[   42.307653] ------------[ cut here ]------------
[   42.307657] Kernel BUG at ffffffffba1e4b28 [verbose debug info unavailable]
[   42.307720] invalid opcode: 0000 [#1] SMP DEBUG_PAGEALLOC
[   42.312512] Modules linked in: vmw_vsock_vmci_transport vsock ppdev joydev vmw_balloon(-) input_leds serio_raw vmw_vmci parport_pc shpchp parport i2c_piix4 nfit mac_hid autofs4 vmwgfx drm_kms_helper hid_generic syscopyarea sysfillrect usbhid sysimgblt fb_sys_fops hid ttm mptspi scsi_transport_spi ahci mptscsih drm psmouse vmxnet3 libahci mptbase pata_acpi
[   42.312766] CPU: 10 PID: 1527 Comm: rmmod Not tainted 4.12.0+ #5
[   42.312803] Hardware name: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 09/30/2016
[   42.313042] task: ffff9bf9680f8000 task.stack: ffffbfefc1638000
[   42.313290] RIP: 0010:__free_pages+0x38/0x40
[   42.313510] RSP: 0018:ffffbfefc163be98 EFLAGS: 00010246
[   42.313731] RAX: 000000000000003e RBX: ffffffffc02b9720 RCX: 0000000000000006
[   42.313972] RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff9bf97e08e0a0
[   42.314201] RBP: ffffbfefc163be98 R08: 0000000000000000 R09: 0000000000000000
[   42.314435] R10: 0000000000000000 R11: 0000000000000000 R12: ffffffffc02b97e4
[   42.314505] R13: ffffffffc02b9748 R14: ffffffffc02b9728 R15: 0000000000000200
[   42.314550] FS:  00007f3af5fec700(0000) GS:ffff9bf97e080000(0000) knlGS:0000000000000000
[   42.314599] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   42.314635] CR2: 00007f44f6f4ab24 CR3: 00000003a7d12000 CR4: 00000000000006e0
[   42.314864] Call Trace:
[   42.315774]  vmballoon_pop+0x102/0x130 [vmw_balloon]
[   42.315816]  vmballoon_exit+0x42/0xd64 [vmw_balloon]
[   42.315853]  SyS_delete_module+0x1e2/0x250
[   42.315891]  entry_SYSCALL_64_fastpath+0x23/0xc2
[   42.315924] RIP: 0033:0x7f3af5b0e8e7
[   42.315949] RSP: 002b:00007fffe6ce0148 EFLAGS: 00000206 ORIG_RAX: 00000000000000b0
[   42.315996] RAX: ffffffffffffffda RBX: 000055be676401e0 RCX: 00007f3af5b0e8e7
[   42.316951] RDX: 000000000000000a RSI: 0000000000000800 RDI: 000055be67640248
[   42.317887] RBP: 0000000000000003 R08: 0000000000000000 R09: 1999999999999999
[   42.318845] R10: 0000000000000883 R11: 0000000000000206 R12: 00007fffe6cdf130
[   42.319755] R13: 0000000000000000 R14: 0000000000000000 R15: 000055be676401e0
[   42.320606] Code: c0 74 1c f0 ff 4f 1c 74 02 5d c3 85 f6 74 07 e8 0f d8 ff ff 5d c3 31 f6 e8 c6 fb ff ff 5d c3 48 c7 c6 c8 0f c5 ba e8 58 be 02 00 <0f> 0b 66 0f 1f 44 00 00 66 66 66 66 90 48 85 ff 75 01 c3 55 48
[   42.323462] RIP: __free_pages+0x38/0x40 RSP: ffffbfefc163be98
[   42.325735] ---[ end trace 872e008e33f81508 ]---

To solve the bug, we eliminate the dual purpose of balloon.page.

Fixes: f220a80 ("VMware balloon: add batching to the vmw_balloon.")
Cc: stable@vger.kernel.org
Reported-by: Oleksandr Natalenko <onatalen@redhat.com>
Signed-off-by: Gil Kupfer <gilkup@gmail.com>
Signed-off-by: Nadav Amit <namit@vmware.com>
Reviewed-by: Xavier Deguillard <xdeguillard@vmware.com>
Tested-by: Oleksandr Natalenko <oleksandr@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
koenkooi pushed a commit that referenced this pull request Feb 7, 2020
commit 0216234 upstream.

We release wrong pointer on error path in cpu_cache_level__read
function, leading to segfault:

  (gdb) r record ls
  Starting program: /root/perf/tools/perf/perf record ls
  ...
  [ perf record: Woken up 1 times to write data ]
  double free or corruption (out)

  Thread 1 "perf" received signal SIGABRT, Aborted.
  0x00007ffff7463798 in raise () from /lib64/power9/libc.so.6
  (gdb) bt
  #0  0x00007ffff7463798 in raise () from /lib64/power9/libc.so.6
  #1  0x00007ffff7443bac in abort () from /lib64/power9/libc.so.6
  #2  0x00007ffff74af8bc in __libc_message () from /lib64/power9/libc.so.6
  #3  0x00007ffff74b92b8 in malloc_printerr () from /lib64/power9/libc.so.6
  #4  0x00007ffff74bb874 in _int_free () from /lib64/power9/libc.so.6
  #5  0x0000000010271260 in __zfree (ptr=0x7fffffffa0b0) at ../../lib/zalloc..
  #6  0x0000000010139340 in cpu_cache_level__read (cache=0x7fffffffa090, cac..
  #7  0x0000000010143c90 in build_caches (cntp=0x7fffffffa118, size=<optimiz..
  ...

Releasing the proper pointer.

Fixes: 720e98b ("perf tools: Add perf data cache feature")
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: stable@vger.kernel.org: # v4.6+
Link: http://lore.kernel.org/lkml/20190912105235.10689-1-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
koenkooi pushed a commit that referenced this pull request Feb 7, 2020
commit 443f2d5 upstream.

Observe a segmentation fault when 'perf stat' is asked to repeat forever
with the interval option.

Without fix:

  # perf stat -r 0 -I 5000 -e cycles -a sleep 10
  #           time             counts unit events
       5.000211692  3,13,89,82,34,157      cycles
      10.000380119  1,53,98,52,22,294      cycles
      10.040467280       17,16,79,265      cycles
  Segmentation fault

This problem was only observed when we use forever option aka -r 0 and
works with limited repeats. Calling print_counter with ts being set to
NULL, is not a correct option when interval is set. Hence avoid
print_counter(NULL,..)  if interval is set.

With fix:

  # perf stat -r 0 -I 5000 -e cycles -a sleep 10
   #           time             counts unit events
       5.019866622  3,15,14,43,08,697      cycles
      10.039865756  3,15,16,31,95,261      cycles
      10.059950628     1,26,05,47,158      cycles
       5.009902655  3,14,52,62,33,932      cycles
      10.019880228  3,14,52,22,89,154      cycles
      10.030543876       66,90,18,333      cycles
       5.009848281  3,14,51,98,25,437      cycles
      10.029854402  3,15,14,93,04,918      cycles
       5.009834177  3,14,51,95,92,316      cycles

Committer notes:

Did the 'git bisect' to find the cset introducing the problem to add the
Fixes tag below, and at that time the problem reproduced as:

  (gdb) run stat -r0 -I500 sleep 1
  <SNIP>
  Program received signal SIGSEGV, Segmentation fault.
  print_interval (prefix=prefix@entry=0x7fffffffc8d0 "", ts=ts@entry=0x0) at builtin-stat.c:866
  866		sprintf(prefix, "%6lu.%09lu%s", ts->tv_sec, ts->tv_nsec, csv_sep);
  (gdb) bt
  #0  print_interval (prefix=prefix@entry=0x7fffffffc8d0 "", ts=ts@entry=0x0) at builtin-stat.c:866
  #1  0x000000000041860a in print_counters (ts=ts@entry=0x0, argc=argc@entry=2, argv=argv@entry=0x7fffffffd640) at builtin-stat.c:938
  #2  0x0000000000419a7f in cmd_stat (argc=2, argv=0x7fffffffd640, prefix=<optimized out>) at builtin-stat.c:1411
  #3  0x000000000045c65a in run_builtin (p=p@entry=0x6291b8 <commands+216>, argc=argc@entry=5, argv=argv@entry=0x7fffffffd640) at perf.c:370
  #4  0x000000000045c893 in handle_internal_command (argc=5, argv=0x7fffffffd640) at perf.c:429
  #5  0x000000000045c8f1 in run_argv (argcp=argcp@entry=0x7fffffffd4ac, argv=argv@entry=0x7fffffffd4a0) at perf.c:473
  #6  0x000000000045cac9 in main (argc=<optimized out>, argv=<optimized out>) at perf.c:588
  (gdb)

Mostly the same as just before this patch:

  Program received signal SIGSEGV, Segmentation fault.
  0x00000000005874a7 in print_interval (config=0xa1f2a0 <stat_config>, evlist=0xbc9b90, prefix=0x7fffffffd1c0 "`", ts=0x0) at util/stat-display.c:964
  964		sprintf(prefix, "%6lu.%09lu%s", ts->tv_sec, ts->tv_nsec, config->csv_sep);
  (gdb) bt
  #0  0x00000000005874a7 in print_interval (config=0xa1f2a0 <stat_config>, evlist=0xbc9b90, prefix=0x7fffffffd1c0 "`", ts=0x0) at util/stat-display.c:964
  #1  0x0000000000588047 in perf_evlist__print_counters (evlist=0xbc9b90, config=0xa1f2a0 <stat_config>, _target=0xa1f0c0 <target>, ts=0x0, argc=2, argv=0x7fffffffd670)
      at util/stat-display.c:1172
  #2  0x000000000045390f in print_counters (ts=0x0, argc=2, argv=0x7fffffffd670) at builtin-stat.c:656
  #3  0x0000000000456bb5 in cmd_stat (argc=2, argv=0x7fffffffd670) at builtin-stat.c:1960
  #4  0x00000000004dd2e0 in run_builtin (p=0xa30e00 <commands+288>, argc=5, argv=0x7fffffffd670) at perf.c:310
  #5  0x00000000004dd54d in handle_internal_command (argc=5, argv=0x7fffffffd670) at perf.c:362
  #6  0x00000000004dd694 in run_argv (argcp=0x7fffffffd4cc, argv=0x7fffffffd4c0) at perf.c:406
  #7  0x00000000004dda11 in main (argc=5, argv=0x7fffffffd670) at perf.c:531
  (gdb)

Fixes: d4f63a4 ("perf stat: Introduce print_counters function")
Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Tested-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Cc: stable@vger.kernel.org # v4.2+
Link: http://lore.kernel.org/lkml/20190904094738.9558-3-srikar@linux.vnet.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
koenkooi pushed a commit that referenced this pull request Feb 7, 2020
commit a8fabb3 upstream.

In case a user process using xenbus has open transactions and is killed
e.g. via ctrl-C the following cleanup of the allocated resources might
result in a deadlock due to trying to end a transaction in the xenbus
worker thread:

[ 2551.474706] INFO: task xenbus:37 blocked for more than 120 seconds.
[ 2551.492215]       Tainted: P           OE     5.0.0-29-generic #5
[ 2551.510263] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
[ 2551.528585] xenbus          D    0    37      2 0x80000080
[ 2551.528590] Call Trace:
[ 2551.528603]  __schedule+0x2c0/0x870
[ 2551.528606]  ? _cond_resched+0x19/0x40
[ 2551.528632]  schedule+0x2c/0x70
[ 2551.528637]  xs_talkv+0x1ec/0x2b0
[ 2551.528642]  ? wait_woken+0x80/0x80
[ 2551.528645]  xs_single+0x53/0x80
[ 2551.528648]  xenbus_transaction_end+0x3b/0x70
[ 2551.528651]  xenbus_file_free+0x5a/0x160
[ 2551.528654]  xenbus_dev_queue_reply+0xc4/0x220
[ 2551.528657]  xenbus_thread+0x7de/0x880
[ 2551.528660]  ? wait_woken+0x80/0x80
[ 2551.528665]  kthread+0x121/0x140
[ 2551.528667]  ? xb_read+0x1d0/0x1d0
[ 2551.528670]  ? kthread_park+0x90/0x90
[ 2551.528673]  ret_from_fork+0x35/0x40

Fix this by doing the cleanup via a workqueue instead.

Reported-by: James Dingwall <james@dingwall.me.uk>
Fixes: fd8aa90 ("xen: optimize xenbus driver for multiple concurrent xenstore accesses")
Cc: <stable@vger.kernel.org> # 4.11
Signed-off-by: Juergen Gross <jgross@suse.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
koenkooi pushed a commit that referenced this pull request Feb 7, 2020
commit cabe5f8 upstream.

The baseboard of the Logic PD i.MX6 development kit has a power
button routed which can both power down and power up the board.
It can also wake the board from sleep.  This functionality was
marked as disabled by default in imx6qdl.dtsi, so it needs to
be explicitly enabled for each board.

This patch enables the snvs power key again.

Signed-off-by: Adam Ford <aford173@gmail.com>
Fixes: 770856f ("ARM: dts: imx6qdl: Enable SNVS power key according to board design")
Cc: stable <stable@vger.kernel.org> #5.3+
Signed-off-by: Shawn Guo <shawnguo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
koenkooi pushed a commit that referenced this pull request Nov 4, 2020
[ Upstream commit ab0db04 ]

When running with -o enospc_debug you can get the following splat if one
of the dump_space_info's trip

  ======================================================
  WARNING: possible circular locking dependency detected
  5.8.0-rc5+ torvalds#20 Tainted: G           OE
  ------------------------------------------------------
  dd/563090 is trying to acquire lock:
  ffff9e7dbf4f1e18 (&ctl->tree_lock){+.+.}-{2:2}, at: btrfs_dump_free_space+0x2b/0xa0 [btrfs]

  but task is already holding lock:
  ffff9e7e2284d428 (&cache->lock){+.+.}-{2:2}, at: btrfs_dump_space_info+0xaa/0x120 [btrfs]

  which lock already depends on the new lock.

  the existing dependency chain (in reverse order) is:

  -> #3 (&cache->lock){+.+.}-{2:2}:
	 _raw_spin_lock+0x25/0x30
	 btrfs_add_reserved_bytes+0x3c/0x3c0 [btrfs]
	 find_free_extent+0x7ef/0x13b0 [btrfs]
	 btrfs_reserve_extent+0x9b/0x180 [btrfs]
	 btrfs_alloc_tree_block+0xc1/0x340 [btrfs]
	 alloc_tree_block_no_bg_flush+0x4a/0x60 [btrfs]
	 __btrfs_cow_block+0x122/0x530 [btrfs]
	 btrfs_cow_block+0x106/0x210 [btrfs]
	 commit_cowonly_roots+0x55/0x300 [btrfs]
	 btrfs_commit_transaction+0x4ed/0xac0 [btrfs]
	 sync_filesystem+0x74/0x90
	 generic_shutdown_super+0x22/0x100
	 kill_anon_super+0x14/0x30
	 btrfs_kill_super+0x12/0x20 [btrfs]
	 deactivate_locked_super+0x36/0x70
	 cleanup_mnt+0x104/0x160
	 task_work_run+0x5f/0x90
	 __prepare_exit_to_usermode+0x1bd/0x1c0
	 do_syscall_64+0x5e/0xb0
	 entry_SYSCALL_64_after_hwframe+0x44/0xa9

  -> #2 (&space_info->lock){+.+.}-{2:2}:
	 _raw_spin_lock+0x25/0x30
	 btrfs_block_rsv_release+0x1a6/0x3f0 [btrfs]
	 btrfs_inode_rsv_release+0x4f/0x170 [btrfs]
	 btrfs_clear_delalloc_extent+0x155/0x480 [btrfs]
	 clear_state_bit+0x81/0x1a0 [btrfs]
	 __clear_extent_bit+0x25c/0x5d0 [btrfs]
	 clear_extent_bit+0x15/0x20 [btrfs]
	 btrfs_invalidatepage+0x2b7/0x3c0 [btrfs]
	 truncate_cleanup_page+0x47/0xe0
	 truncate_inode_pages_range+0x238/0x840
	 truncate_pagecache+0x44/0x60
	 btrfs_setattr+0x202/0x5e0 [btrfs]
	 notify_change+0x33b/0x490
	 do_truncate+0x76/0xd0
	 path_openat+0x687/0xa10
	 do_filp_open+0x91/0x100
	 do_sys_openat2+0x215/0x2d0
	 do_sys_open+0x44/0x80
	 do_syscall_64+0x52/0xb0
	 entry_SYSCALL_64_after_hwframe+0x44/0xa9

  -> #1 (&tree->lock#2){+.+.}-{2:2}:
	 _raw_spin_lock+0x25/0x30
	 find_first_extent_bit+0x32/0x150 [btrfs]
	 write_pinned_extent_entries.isra.0+0xc5/0x100 [btrfs]
	 __btrfs_write_out_cache+0x172/0x480 [btrfs]
	 btrfs_write_out_cache+0x7a/0xf0 [btrfs]
	 btrfs_write_dirty_block_groups+0x286/0x3b0 [btrfs]
	 commit_cowonly_roots+0x245/0x300 [btrfs]
	 btrfs_commit_transaction+0x4ed/0xac0 [btrfs]
	 close_ctree+0xf9/0x2f5 [btrfs]
	 generic_shutdown_super+0x6c/0x100
	 kill_anon_super+0x14/0x30
	 btrfs_kill_super+0x12/0x20 [btrfs]
	 deactivate_locked_super+0x36/0x70
	 cleanup_mnt+0x104/0x160
	 task_work_run+0x5f/0x90
	 __prepare_exit_to_usermode+0x1bd/0x1c0
	 do_syscall_64+0x5e/0xb0
	 entry_SYSCALL_64_after_hwframe+0x44/0xa9

  -> #0 (&ctl->tree_lock){+.+.}-{2:2}:
	 __lock_acquire+0x1240/0x2460
	 lock_acquire+0xab/0x360
	 _raw_spin_lock+0x25/0x30
	 btrfs_dump_free_space+0x2b/0xa0 [btrfs]
	 btrfs_dump_space_info+0xf4/0x120 [btrfs]
	 btrfs_reserve_extent+0x176/0x180 [btrfs]
	 __btrfs_prealloc_file_range+0x145/0x550 [btrfs]
	 cache_save_setup+0x28d/0x3b0 [btrfs]
	 btrfs_start_dirty_block_groups+0x1fc/0x4f0 [btrfs]
	 btrfs_commit_transaction+0xcc/0xac0 [btrfs]
	 btrfs_alloc_data_chunk_ondemand+0x162/0x4c0 [btrfs]
	 btrfs_check_data_free_space+0x4c/0xa0 [btrfs]
	 btrfs_buffered_write.isra.0+0x19b/0x740 [btrfs]
	 btrfs_file_write_iter+0x3cf/0x610 [btrfs]
	 new_sync_write+0x11e/0x1b0
	 vfs_write+0x1c9/0x200
	 ksys_write+0x68/0xe0
	 do_syscall_64+0x52/0xb0
	 entry_SYSCALL_64_after_hwframe+0x44/0xa9

  other info that might help us debug this:

  Chain exists of:
    &ctl->tree_lock --> &space_info->lock --> &cache->lock

   Possible unsafe locking scenario:

	 CPU0                    CPU1
	 ----                    ----
    lock(&cache->lock);
				 lock(&space_info->lock);
				 lock(&cache->lock);
    lock(&ctl->tree_lock);

   *** DEADLOCK ***

  6 locks held by dd/563090:
   #0: ffff9e7e21d18448 (sb_writers#14){.+.+}-{0:0}, at: vfs_write+0x195/0x200
   #1: ffff9e7dd0410ed8 (&sb->s_type->i_mutex_key#19){++++}-{3:3}, at: btrfs_file_write_iter+0x86/0x610 [btrfs]
   #2: ffff9e7e21d18638 (sb_internal#2){.+.+}-{0:0}, at: start_transaction+0x40b/0x5b0 [btrfs]
   #3: ffff9e7e1f05d688 (&cur_trans->cache_write_mutex){+.+.}-{3:3}, at: btrfs_start_dirty_block_groups+0x158/0x4f0 [btrfs]
   #4: ffff9e7e2284ddb8 (&space_info->groups_sem){++++}-{3:3}, at: btrfs_dump_space_info+0x69/0x120 [btrfs]
   #5: ffff9e7e2284d428 (&cache->lock){+.+.}-{2:2}, at: btrfs_dump_space_info+0xaa/0x120 [btrfs]

  stack backtrace:
  CPU: 3 PID: 563090 Comm: dd Tainted: G           OE     5.8.0-rc5+ torvalds#20
  Hardware name: To Be Filled By O.E.M. To Be Filled By O.E.M./890FX Deluxe5, BIOS P1.40 05/03/2011
  Call Trace:
   dump_stack+0x96/0xd0
   check_noncircular+0x162/0x180
   __lock_acquire+0x1240/0x2460
   ? wake_up_klogd.part.0+0x30/0x40
   lock_acquire+0xab/0x360
   ? btrfs_dump_free_space+0x2b/0xa0 [btrfs]
   _raw_spin_lock+0x25/0x30
   ? btrfs_dump_free_space+0x2b/0xa0 [btrfs]
   btrfs_dump_free_space+0x2b/0xa0 [btrfs]
   btrfs_dump_space_info+0xf4/0x120 [btrfs]
   btrfs_reserve_extent+0x176/0x180 [btrfs]
   __btrfs_prealloc_file_range+0x145/0x550 [btrfs]
   ? btrfs_qgroup_reserve_data+0x1d/0x60 [btrfs]
   cache_save_setup+0x28d/0x3b0 [btrfs]
   btrfs_start_dirty_block_groups+0x1fc/0x4f0 [btrfs]
   btrfs_commit_transaction+0xcc/0xac0 [btrfs]
   ? start_transaction+0xe0/0x5b0 [btrfs]
   btrfs_alloc_data_chunk_ondemand+0x162/0x4c0 [btrfs]
   btrfs_check_data_free_space+0x4c/0xa0 [btrfs]
   btrfs_buffered_write.isra.0+0x19b/0x740 [btrfs]
   ? ktime_get_coarse_real_ts64+0xa8/0xd0
   ? trace_hardirqs_on+0x1c/0xe0
   btrfs_file_write_iter+0x3cf/0x610 [btrfs]
   new_sync_write+0x11e/0x1b0
   vfs_write+0x1c9/0x200
   ksys_write+0x68/0xe0
   do_syscall_64+0x52/0xb0
   entry_SYSCALL_64_after_hwframe+0x44/0xa9

This is because we're holding the block_group->lock while trying to dump
the free space cache.  However we don't need this lock, we just need it
to read the values for the printk, so move the free space cache dumping
outside of the block group lock.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
koenkooi pushed a commit that referenced this pull request Nov 4, 2020
commit 18c850f upstream.

There's long existed a lockdep splat because we open our bdev's under
the ->device_list_mutex at mount time, which acquires the bd_mutex.
Usually this goes unnoticed, but if you do loopback devices at all
suddenly the bd_mutex comes with a whole host of other dependencies,
which results in the splat when you mount a btrfs file system.

======================================================
WARNING: possible circular locking dependency detected
5.8.0-0.rc3.1.fc33.x86_64+debug #1 Not tainted
------------------------------------------------------
systemd-journal/509 is trying to acquire lock:
ffff970831f84db0 (&fs_info->reloc_mutex){+.+.}-{3:3}, at: btrfs_record_root_in_trans+0x44/0x70 [btrfs]

but task is already holding lock:
ffff97083144d598 (sb_pagefaults){.+.+}-{0:0}, at: btrfs_page_mkwrite+0x59/0x560 [btrfs]

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

 -> #6 (sb_pagefaults){.+.+}-{0:0}:
       __sb_start_write+0x13e/0x220
       btrfs_page_mkwrite+0x59/0x560 [btrfs]
       do_page_mkwrite+0x4f/0x130
       do_wp_page+0x3b0/0x4f0
       handle_mm_fault+0xf47/0x1850
       do_user_addr_fault+0x1fc/0x4b0
       exc_page_fault+0x88/0x300
       asm_exc_page_fault+0x1e/0x30

 -> #5 (&mm->mmap_lock#2){++++}-{3:3}:
       __might_fault+0x60/0x80
       _copy_from_user+0x20/0xb0
       get_sg_io_hdr+0x9a/0xb0
       scsi_cmd_ioctl+0x1ea/0x2f0
       cdrom_ioctl+0x3c/0x12b4
       sr_block_ioctl+0xa4/0xd0
       block_ioctl+0x3f/0x50
       ksys_ioctl+0x82/0xc0
       __x64_sys_ioctl+0x16/0x20
       do_syscall_64+0x52/0xb0
       entry_SYSCALL_64_after_hwframe+0x44/0xa9

 -> #4 (&cd->lock){+.+.}-{3:3}:
       __mutex_lock+0x7b/0x820
       sr_block_open+0xa2/0x180
       __blkdev_get+0xdd/0x550
       blkdev_get+0x38/0x150
       do_dentry_open+0x16b/0x3e0
       path_openat+0x3c9/0xa00
       do_filp_open+0x75/0x100
       do_sys_openat2+0x8a/0x140
       __x64_sys_openat+0x46/0x70
       do_syscall_64+0x52/0xb0
       entry_SYSCALL_64_after_hwframe+0x44/0xa9

 -> #3 (&bdev->bd_mutex){+.+.}-{3:3}:
       __mutex_lock+0x7b/0x820
       __blkdev_get+0x6a/0x550
       blkdev_get+0x85/0x150
       blkdev_get_by_path+0x2c/0x70
       btrfs_get_bdev_and_sb+0x1b/0xb0 [btrfs]
       open_fs_devices+0x88/0x240 [btrfs]
       btrfs_open_devices+0x92/0xa0 [btrfs]
       btrfs_mount_root+0x250/0x490 [btrfs]
       legacy_get_tree+0x30/0x50
       vfs_get_tree+0x28/0xc0
       vfs_kern_mount.part.0+0x71/0xb0
       btrfs_mount+0x119/0x380 [btrfs]
       legacy_get_tree+0x30/0x50
       vfs_get_tree+0x28/0xc0
       do_mount+0x8c6/0xca0
       __x64_sys_mount+0x8e/0xd0
       do_syscall_64+0x52/0xb0
       entry_SYSCALL_64_after_hwframe+0x44/0xa9

 -> #2 (&fs_devs->device_list_mutex){+.+.}-{3:3}:
       __mutex_lock+0x7b/0x820
       btrfs_run_dev_stats+0x36/0x420 [btrfs]
       commit_cowonly_roots+0x91/0x2d0 [btrfs]
       btrfs_commit_transaction+0x4e6/0x9f0 [btrfs]
       btrfs_sync_file+0x38a/0x480 [btrfs]
       __x64_sys_fdatasync+0x47/0x80
       do_syscall_64+0x52/0xb0
       entry_SYSCALL_64_after_hwframe+0x44/0xa9

 -> #1 (&fs_info->tree_log_mutex){+.+.}-{3:3}:
       __mutex_lock+0x7b/0x820
       btrfs_commit_transaction+0x48e/0x9f0 [btrfs]
       btrfs_sync_file+0x38a/0x480 [btrfs]
       __x64_sys_fdatasync+0x47/0x80
       do_syscall_64+0x52/0xb0
       entry_SYSCALL_64_after_hwframe+0x44/0xa9

 -> #0 (&fs_info->reloc_mutex){+.+.}-{3:3}:
       __lock_acquire+0x1241/0x20c0
       lock_acquire+0xb0/0x400
       __mutex_lock+0x7b/0x820
       btrfs_record_root_in_trans+0x44/0x70 [btrfs]
       start_transaction+0xd2/0x500 [btrfs]
       btrfs_dirty_inode+0x44/0xd0 [btrfs]
       file_update_time+0xc6/0x120
       btrfs_page_mkwrite+0xda/0x560 [btrfs]
       do_page_mkwrite+0x4f/0x130
       do_wp_page+0x3b0/0x4f0
       handle_mm_fault+0xf47/0x1850
       do_user_addr_fault+0x1fc/0x4b0
       exc_page_fault+0x88/0x300
       asm_exc_page_fault+0x1e/0x30

other info that might help us debug this:

Chain exists of:
  &fs_info->reloc_mutex --> &mm->mmap_lock#2 --> sb_pagefaults

Possible unsafe locking scenario:

     CPU0                    CPU1
     ----                    ----
 lock(sb_pagefaults);
                             lock(&mm->mmap_lock#2);
                             lock(sb_pagefaults);
 lock(&fs_info->reloc_mutex);

 *** DEADLOCK ***

3 locks held by systemd-journal/509:
 #0: ffff97083bdec8b8 (&mm->mmap_lock#2){++++}-{3:3}, at: do_user_addr_fault+0x12e/0x4b0
 #1: ffff97083144d598 (sb_pagefaults){.+.+}-{0:0}, at: btrfs_page_mkwrite+0x59/0x560 [btrfs]
 #2: ffff97083144d6a8 (sb_internal){.+.+}-{0:0}, at: start_transaction+0x3f8/0x500 [btrfs]

stack backtrace:
CPU: 0 PID: 509 Comm: systemd-journal Not tainted 5.8.0-0.rc3.1.fc33.x86_64+debug #1
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015
Call Trace:
 dump_stack+0x92/0xc8
 check_noncircular+0x134/0x150
 __lock_acquire+0x1241/0x20c0
 lock_acquire+0xb0/0x400
 ? btrfs_record_root_in_trans+0x44/0x70 [btrfs]
 ? lock_acquire+0xb0/0x400
 ? btrfs_record_root_in_trans+0x44/0x70 [btrfs]
 __mutex_lock+0x7b/0x820
 ? btrfs_record_root_in_trans+0x44/0x70 [btrfs]
 ? kvm_sched_clock_read+0x14/0x30
 ? sched_clock+0x5/0x10
 ? sched_clock_cpu+0xc/0xb0
 btrfs_record_root_in_trans+0x44/0x70 [btrfs]
 start_transaction+0xd2/0x500 [btrfs]
 btrfs_dirty_inode+0x44/0xd0 [btrfs]
 file_update_time+0xc6/0x120
 btrfs_page_mkwrite+0xda/0x560 [btrfs]
 ? sched_clock+0x5/0x10
 do_page_mkwrite+0x4f/0x130
 do_wp_page+0x3b0/0x4f0
 handle_mm_fault+0xf47/0x1850
 do_user_addr_fault+0x1fc/0x4b0
 exc_page_fault+0x88/0x300
 ? asm_exc_page_fault+0x8/0x30
 asm_exc_page_fault+0x1e/0x30
RIP: 0033:0x7fa3972fdbfe
Code: Bad RIP value.

Fix this by not holding the ->device_list_mutex at this point.  The
device_list_mutex exists to protect us from modifying the device list
while the file system is running.

However it can also be modified by doing a scan on a device.  But this
action is specifically protected by the uuid_mutex, which we are holding
here.  We cannot race with opening at this point because we have the
->s_mount lock held during the mount.  Not having the
->device_list_mutex here is perfectly safe as we're not going to change
the devices at this point.

CC: stable@vger.kernel.org # 4.19+
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ add some comments ]
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
koenkooi pushed a commit that referenced this pull request Nov 4, 2020
… set

[ Upstream commit 1101c87 ]

We received an error report that perf-record caused 'Segmentation fault'
on a newly system (e.g. on the new installed ubuntu).

  (gdb) backtrace
  #0  __read_once_size (size=4, res=<synthetic pointer>, p=0x14) at /root/0-jinyao/acme/tools/include/linux/compiler.h:139
  #1  atomic_read (v=0x14) at /root/0-jinyao/acme/tools/include/asm/../../arch/x86/include/asm/atomic.h:28
  #2  refcount_read (r=0x14) at /root/0-jinyao/acme/tools/include/linux/refcount.h:65
  #3  perf_mmap__read_init (map=map@entry=0x0) at mmap.c:177
  #4  0x0000561ce5c0de39 in perf_evlist__poll_thread (arg=0x561ce68584d0) at util/sideband_evlist.c:62
  #5  0x00007fad78491609 in start_thread (arg=<optimized out>) at pthread_create.c:477
  #6  0x00007fad7823c103 in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:95

The root cause is, evlist__add_bpf_sb_event() just returns 0 if
HAVE_LIBBPF_SUPPORT is not defined (inline function path). So it will
not create a valid evsel for side-band event.

But perf-record still creates BPF side band thread to process the
side-band event, then the error happpens.

We can reproduce this issue by removing the libelf-dev. e.g.
1. apt-get remove libelf-dev
2. perf record -a -- sleep 1

  root@test:~# ./perf record -a -- sleep 1
  perf: Segmentation fault
  Obtained 6 stack frames.
  ./perf(+0x28eee8) [0x5562d6ef6ee8]
  /lib/x86_64-linux-gnu/libc.so.6(+0x46210) [0x7fbfdc65f210]
  ./perf(+0x342e74) [0x5562d6faae74]
  ./perf(+0x257e39) [0x5562d6ebfe39]
  /lib/x86_64-linux-gnu/libpthread.so.0(+0x9609) [0x7fbfdc990609]
  /lib/x86_64-linux-gnu/libc.so.6(clone+0x43) [0x7fbfdc73b103]
  Segmentation fault (core dumped)

To fix this issue,

1. We either install the missing libraries to let HAVE_LIBBPF_SUPPORT
   be defined.
   e.g. apt-get install libelf-dev and install other related libraries.

2. Use this patch to skip the side-band event setup if HAVE_LIBBPF_SUPPORT
   is not set.

Committer notes:

The side band thread is not used just with BPF, it is also used with
--switch-output-event, so narrow the ifdef to the BPF specific part.

Fixes: 23cbb41 ("perf record: Move side band evlist setup to separate routine")
Signed-off-by: Jin Yao <yao.jin@linux.intel.com>
Acked-by: Jiri Olsa <jolsa@kernel.org>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Jin Yao <yao.jin@intel.com>
Cc: Kan Liang <kan.liang@linux.intel.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lore.kernel.org/lkml/20200805022937.29184-1-yao.jin@linux.intel.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
koenkooi pushed a commit that referenced this pull request Nov 4, 2020
[ Upstream commit b0f3b87 ]

https://bugzilla.kernel.org/show_bug.cgi?id=208565

PID: 257    TASK: ecdd0000  CPU: 0   COMMAND: "init"
  #0 [<c0b420ec>] (__schedule) from [<c0b423c8>]
  #1 [<c0b423c8>] (schedule) from [<c0b459d4>]
  #2 [<c0b459d4>] (rwsem_down_read_failed) from [<c0b44fa0>]
  #3 [<c0b44fa0>] (down_read) from [<c044233c>]
  #4 [<c044233c>] (f2fs_truncate_blocks) from [<c0442890>]
  #5 [<c0442890>] (f2fs_truncate) from [<c044d408>]
  #6 [<c044d408>] (f2fs_evict_inode) from [<c030be18>]
  #7 [<c030be18>] (evict) from [<c030a558>]
  #8 [<c030a558>] (iput) from [<c047c600>]
  #9 [<c047c600>] (f2fs_sync_node_pages) from [<c0465414>]
 torvalds#10 [<c0465414>] (f2fs_write_checkpoint) from [<c04575f4>]
 torvalds#11 [<c04575f4>] (f2fs_sync_fs) from [<c0441918>]
 torvalds#12 [<c0441918>] (f2fs_do_sync_file) from [<c0441098>]
 torvalds#13 [<c0441098>] (f2fs_sync_file) from [<c0323fa0>]
 torvalds#14 [<c0323fa0>] (vfs_fsync_range) from [<c0324294>]
 torvalds#15 [<c0324294>] (do_fsync) from [<c0324014>]
 torvalds#16 [<c0324014>] (sys_fsync) from [<c0108bc0>]

This can be caused by flush_dirty_inode() in f2fs_sync_node_pages() where
iput() requires f2fs_lock_op() again resulting in livelock.

Reported-by: Zhiguo Niu <Zhiguo.Niu@unisoc.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
koenkooi pushed a commit that referenced this pull request Nov 4, 2020
commit e89c4a9 upstream.

I got the following lockdep splat while testing:

  ======================================================
  WARNING: possible circular locking dependency detected
  5.8.0-rc7-00172-g021118712e59 torvalds#932 Not tainted
  ------------------------------------------------------
  btrfs/229626 is trying to acquire lock:
  ffffffff828513f0 (cpu_hotplug_lock){++++}-{0:0}, at: alloc_workqueue+0x378/0x450

  but task is already holding lock:
  ffff889dd3889518 (&fs_info->scrub_lock){+.+.}-{3:3}, at: btrfs_scrub_dev+0x11c/0x630

  which lock already depends on the new lock.

  the existing dependency chain (in reverse order) is:

  -> #7 (&fs_info->scrub_lock){+.+.}-{3:3}:
	 __mutex_lock+0x9f/0x930
	 btrfs_scrub_dev+0x11c/0x630
	 btrfs_dev_replace_by_ioctl.cold.21+0x10a/0x1d4
	 btrfs_ioctl+0x2799/0x30a0
	 ksys_ioctl+0x83/0xc0
	 __x64_sys_ioctl+0x16/0x20
	 do_syscall_64+0x50/0x90
	 entry_SYSCALL_64_after_hwframe+0x44/0xa9

  -> #6 (&fs_devs->device_list_mutex){+.+.}-{3:3}:
	 __mutex_lock+0x9f/0x930
	 btrfs_run_dev_stats+0x49/0x480
	 commit_cowonly_roots+0xb5/0x2a0
	 btrfs_commit_transaction+0x516/0xa60
	 sync_filesystem+0x6b/0x90
	 generic_shutdown_super+0x22/0x100
	 kill_anon_super+0xe/0x30
	 btrfs_kill_super+0x12/0x20
	 deactivate_locked_super+0x29/0x60
	 cleanup_mnt+0xb8/0x140
	 task_work_run+0x6d/0xb0
	 __prepare_exit_to_usermode+0x1cc/0x1e0
	 do_syscall_64+0x5c/0x90
	 entry_SYSCALL_64_after_hwframe+0x44/0xa9

  -> #5 (&fs_info->tree_log_mutex){+.+.}-{3:3}:
	 __mutex_lock+0x9f/0x930
	 btrfs_commit_transaction+0x4bb/0xa60
	 sync_filesystem+0x6b/0x90
	 generic_shutdown_super+0x22/0x100
	 kill_anon_super+0xe/0x30
	 btrfs_kill_super+0x12/0x20
	 deactivate_locked_super+0x29/0x60
	 cleanup_mnt+0xb8/0x140
	 task_work_run+0x6d/0xb0
	 __prepare_exit_to_usermode+0x1cc/0x1e0
	 do_syscall_64+0x5c/0x90
	 entry_SYSCALL_64_after_hwframe+0x44/0xa9

  -> #4 (&fs_info->reloc_mutex){+.+.}-{3:3}:
	 __mutex_lock+0x9f/0x930
	 btrfs_record_root_in_trans+0x43/0x70
	 start_transaction+0xd1/0x5d0
	 btrfs_dirty_inode+0x42/0xd0
	 touch_atime+0xa1/0xd0
	 btrfs_file_mmap+0x3f/0x60
	 mmap_region+0x3a4/0x640
	 do_mmap+0x376/0x580
	 vm_mmap_pgoff+0xd5/0x120
	 ksys_mmap_pgoff+0x193/0x230
	 do_syscall_64+0x50/0x90
	 entry_SYSCALL_64_after_hwframe+0x44/0xa9

  -> #3 (&mm->mmap_lock#2){++++}-{3:3}:
	 __might_fault+0x68/0x90
	 _copy_to_user+0x1e/0x80
	 perf_read+0x141/0x2c0
	 vfs_read+0xad/0x1b0
	 ksys_read+0x5f/0xe0
	 do_syscall_64+0x50/0x90
	 entry_SYSCALL_64_after_hwframe+0x44/0xa9

  -> #2 (&cpuctx_mutex){+.+.}-{3:3}:
	 __mutex_lock+0x9f/0x930
	 perf_event_init_cpu+0x88/0x150
	 perf_event_init+0x1db/0x20b
	 start_kernel+0x3ae/0x53c
	 secondary_startup_64+0xa4/0xb0

  -> #1 (pmus_lock){+.+.}-{3:3}:
	 __mutex_lock+0x9f/0x930
	 perf_event_init_cpu+0x4f/0x150
	 cpuhp_invoke_callback+0xb1/0x900
	 _cpu_up.constprop.26+0x9f/0x130
	 cpu_up+0x7b/0xc0
	 bringup_nonboot_cpus+0x4f/0x60
	 smp_init+0x26/0x71
	 kernel_init_freeable+0x110/0x258
	 kernel_init+0xa/0x103
	 ret_from_fork+0x1f/0x30

  -> #0 (cpu_hotplug_lock){++++}-{0:0}:
	 __lock_acquire+0x1272/0x2310
	 lock_acquire+0x9e/0x360
	 cpus_read_lock+0x39/0xb0
	 alloc_workqueue+0x378/0x450
	 __btrfs_alloc_workqueue+0x15d/0x200
	 btrfs_alloc_workqueue+0x51/0x160
	 scrub_workers_get+0x5a/0x170
	 btrfs_scrub_dev+0x18c/0x630
	 btrfs_dev_replace_by_ioctl.cold.21+0x10a/0x1d4
	 btrfs_ioctl+0x2799/0x30a0
	 ksys_ioctl+0x83/0xc0
	 __x64_sys_ioctl+0x16/0x20
	 do_syscall_64+0x50/0x90
	 entry_SYSCALL_64_after_hwframe+0x44/0xa9

  other info that might help us debug this:

  Chain exists of:
    cpu_hotplug_lock --> &fs_devs->device_list_mutex --> &fs_info->scrub_lock

   Possible unsafe locking scenario:

	 CPU0                    CPU1
	 ----                    ----
    lock(&fs_info->scrub_lock);
				 lock(&fs_devs->device_list_mutex);
				 lock(&fs_info->scrub_lock);
    lock(cpu_hotplug_lock);

   *** DEADLOCK ***

  2 locks held by btrfs/229626:
   #0: ffff88bfe8bb86e0 (&fs_devs->device_list_mutex){+.+.}-{3:3}, at: btrfs_scrub_dev+0xbd/0x630
   #1: ffff889dd3889518 (&fs_info->scrub_lock){+.+.}-{3:3}, at: btrfs_scrub_dev+0x11c/0x630

  stack backtrace:
  CPU: 15 PID: 229626 Comm: btrfs Kdump: loaded Not tainted 5.8.0-rc7-00172-g021118712e59 torvalds#932
  Hardware name: Quanta Tioga Pass Single Side 01-0030993006/Tioga Pass Single Side, BIOS F08_3A18 12/20/2018
  Call Trace:
   dump_stack+0x78/0xa0
   check_noncircular+0x165/0x180
   __lock_acquire+0x1272/0x2310
   lock_acquire+0x9e/0x360
   ? alloc_workqueue+0x378/0x450
   cpus_read_lock+0x39/0xb0
   ? alloc_workqueue+0x378/0x450
   alloc_workqueue+0x378/0x450
   ? rcu_read_lock_sched_held+0x52/0x80
   __btrfs_alloc_workqueue+0x15d/0x200
   btrfs_alloc_workqueue+0x51/0x160
   scrub_workers_get+0x5a/0x170
   btrfs_scrub_dev+0x18c/0x630
   ? start_transaction+0xd1/0x5d0
   btrfs_dev_replace_by_ioctl.cold.21+0x10a/0x1d4
   btrfs_ioctl+0x2799/0x30a0
   ? do_sigaction+0x102/0x250
   ? lockdep_hardirqs_on_prepare+0xca/0x160
   ? _raw_spin_unlock_irq+0x24/0x30
   ? trace_hardirqs_on+0x1c/0xe0
   ? _raw_spin_unlock_irq+0x24/0x30
   ? do_sigaction+0x102/0x250
   ? ksys_ioctl+0x83/0xc0
   ksys_ioctl+0x83/0xc0
   __x64_sys_ioctl+0x16/0x20
   do_syscall_64+0x50/0x90
   entry_SYSCALL_64_after_hwframe+0x44/0xa9

This happens because we're allocating the scrub workqueues under the
scrub and device list mutex, which brings in a whole host of other
dependencies.

Because the work queue allocation is done with GFP_KERNEL, it can
trigger reclaim, which can lead to a transaction commit, which in turns
needs the device_list_mutex, it can lead to a deadlock. A different
problem for which this fix is a solution.

Fix this by moving the actual allocation outside of the
scrub lock, and then only take the lock once we're ready to actually
assign them to the fs_info.  We'll now have to cleanup the workqueues in
a few more places, so I've added a helper to do the refcount dance to
safely free the workqueues.

CC: stable@vger.kernel.org # 5.4+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
koenkooi pushed a commit that referenced this pull request Nov 4, 2020
[ Upstream commit 8a39e8c ]

When compiling with DEBUG=1 on Fedora 32 I'm getting crash for 'perf
test signal':

  Program received signal SIGSEGV, Segmentation fault.
  0x0000000000c68548 in __test_function ()
  (gdb) bt
  #0  0x0000000000c68548 in __test_function ()
  #1  0x00000000004d62e9 in test_function () at tests/bp_signal.c:61
  #2  0x00000000004d689a in test__bp_signal (test=0xa8e280 <generic_ ...
  #3  0x00000000004b7d49 in run_test (test=0xa8e280 <generic_tests+1 ...
  #4  0x00000000004b7e7f in test_and_print (t=0xa8e280 <generic_test ...
  #5  0x00000000004b8927 in __cmd_test (argc=1, argv=0x7fffffffdce0, ...
  ...

It's caused by the symbol __test_function being in the ".bss" section:

  $ readelf -a ./perf | less
    [Nr] Name              Type             Address           Offset
         Size              EntSize          Flags  Link  Info  Align
    ...
    [28] .bss              NOBITS           0000000000c356a0  008346a0
         00000000000511f8  0000000000000000  WA       0     0     32

  $ nm perf | grep __test_function
  0000000000c68548 B __test_function

I guess most of the time we're just lucky the inline asm ended up in the
".text" section, so making it specific explicit with push and pop
section clauses.

  $ readelf -a ./perf | less
    [Nr] Name              Type             Address           Offset
         Size              EntSize          Flags  Link  Info  Align
    ...
    [13] .text             PROGBITS         0000000000431240  00031240
         0000000000306faa  0000000000000000  AX       0     0     16

  $ nm perf | grep __test_function
  00000000004d62c8 T __test_function

Committer testing:

  $ readelf -wi ~/bin/perf | grep producer -m1
    <c>   DW_AT_producer    : (indirect string, offset: 0x254a): GNU C99 10.2.1 20200723 (Red Hat 10.2.1-1) -mtune=generic -march=x86-64 -ggdb3 -std=gnu99 -fno-omit-frame-pointer -funwind-tables -fstack-protector-all
                                                                                                                                         ^^^^^
                                                                                                                                         ^^^^^
                                                                                                                                         ^^^^^
  $

Before:

  $ perf test signal
  20: Breakpoint overflow signal handler                    : FAILED!
  $

After:

  $ perf test signal
  20: Breakpoint overflow signal handler                    : Ok
  $

Fixes: 8fd34e1 ("perf test: Improve bp_signal")
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Wang Nan <wangnan0@huawei.com>
Link: http://lore.kernel.org/lkml/20200911130005.1842138-1-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
koenkooi pushed a commit that referenced this pull request Nov 4, 2020
[ Upstream commit 22fe5a2 ]

The aliases were never released causing the following leaks:

  Indirect leak of 1224 byte(s) in 9 object(s) allocated from:
    #0 0x7feefb830628 in malloc (/lib/x86_64-linux-gnu/libasan.so.5+0x107628)
    #1 0x56332c8f1b62 in __perf_pmu__new_alias util/pmu.c:322
    #2 0x56332c8f401f in pmu_add_cpu_aliases_map util/pmu.c:778
    #3 0x56332c792ce9 in __test__pmu_event_aliases tests/pmu-events.c:295
    #4 0x56332c792ce9 in test_aliases tests/pmu-events.c:367
    #5 0x56332c76a09b in run_test tests/builtin-test.c:410
    #6 0x56332c76a09b in test_and_print tests/builtin-test.c:440
    #7 0x56332c76ce69 in __cmd_test tests/builtin-test.c:695
    #8 0x56332c76ce69 in cmd_test tests/builtin-test.c:807
    #9 0x56332c7d2214 in run_builtin /home/namhyung/project/linux/tools/perf/perf.c:312
    torvalds#10 0x56332c6701a8 in handle_internal_command /home/namhyung/project/linux/tools/perf/perf.c:364
    torvalds#11 0x56332c6701a8 in run_argv /home/namhyung/project/linux/tools/perf/perf.c:408
    torvalds#12 0x56332c6701a8 in main /home/namhyung/project/linux/tools/perf/perf.c:538
    torvalds#13 0x7feefb359cc9 in __libc_start_main ../csu/libc-start.c:308

Fixes: 956a783 ("perf test: Test pmu-events aliases")
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Reviewed-by: John Garry <john.garry@huawei.com>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lore.kernel.org/lkml/20200915031819.386559-11-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
koenkooi pushed a commit that referenced this pull request Nov 4, 2020
[ Upstream commit b12eea5 ]

The evsel->unit borrows a pointer of pmu event or alias instead of
owns a string.  But tool event (duration_time) passes a result of
strdup() caused a leak.

It was found by ASAN during metric test:

  Direct leak of 210 byte(s) in 70 object(s) allocated from:
    #0 0x7fe366fca0b5 in strdup (/lib/x86_64-linux-gnu/libasan.so.5+0x920b5)
    #1 0x559fbbcc6ea3 in add_event_tool util/parse-events.c:414
    #2 0x559fbbcc6ea3 in parse_events_add_tool util/parse-events.c:1414
    #3 0x559fbbd8474d in parse_events_parse util/parse-events.y:439
    #4 0x559fbbcc95da in parse_events__scanner util/parse-events.c:2096
    #5 0x559fbbcc95da in __parse_events util/parse-events.c:2141
    #6 0x559fbbc28555 in check_parse_id tests/pmu-events.c:406
    #7 0x559fbbc28555 in check_parse_id tests/pmu-events.c:393
    #8 0x559fbbc28555 in check_parse_cpu tests/pmu-events.c:415
    #9 0x559fbbc28555 in test_parsing tests/pmu-events.c:498
    torvalds#10 0x559fbbc0109b in run_test tests/builtin-test.c:410
    torvalds#11 0x559fbbc0109b in test_and_print tests/builtin-test.c:440
    torvalds#12 0x559fbbc03e69 in __cmd_test tests/builtin-test.c:695
    torvalds#13 0x559fbbc03e69 in cmd_test tests/builtin-test.c:807
    torvalds#14 0x559fbbc691f4 in run_builtin /home/namhyung/project/linux/tools/perf/perf.c:312
    torvalds#15 0x559fbbb071a8 in handle_internal_command /home/namhyung/project/linux/tools/perf/perf.c:364
    torvalds#16 0x559fbbb071a8 in run_argv /home/namhyung/project/linux/tools/perf/perf.c:408
    torvalds#17 0x559fbbb071a8 in main /home/namhyung/project/linux/tools/perf/perf.c:538
    torvalds#18 0x7fe366b68cc9 in __libc_start_main ../csu/libc-start.c:308

Fixes: f0fbb11 ("perf stat: Implement duration_time as a proper event")
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lore.kernel.org/lkml/20200915031819.386559-6-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
koenkooi pushed a commit that referenced this pull request Nov 4, 2020
[ Upstream commit d26383d ]

The following leaks were detected by ASAN:

  Indirect leak of 360 byte(s) in 9 object(s) allocated from:
    #0 0x7fecc305180e in calloc (/lib/x86_64-linux-gnu/libasan.so.5+0x10780e)
    #1 0x560578f6dce5 in perf_pmu__new_format util/pmu.c:1333
    #2 0x560578f752fc in perf_pmu_parse util/pmu.y:59
    #3 0x560578f6a8b7 in perf_pmu__format_parse util/pmu.c:73
    #4 0x560578e07045 in test__pmu tests/pmu.c:155
    #5 0x560578de109b in run_test tests/builtin-test.c:410
    #6 0x560578de109b in test_and_print tests/builtin-test.c:440
    #7 0x560578de401a in __cmd_test tests/builtin-test.c:661
    #8 0x560578de401a in cmd_test tests/builtin-test.c:807
    #9 0x560578e49354 in run_builtin /home/namhyung/project/linux/tools/perf/perf.c:312
    torvalds#10 0x560578ce71a8 in handle_internal_command /home/namhyung/project/linux/tools/perf/perf.c:364
    torvalds#11 0x560578ce71a8 in run_argv /home/namhyung/project/linux/tools/perf/perf.c:408
    torvalds#12 0x560578ce71a8 in main /home/namhyung/project/linux/tools/perf/perf.c:538
    torvalds#13 0x7fecc2b7acc9 in __libc_start_main ../csu/libc-start.c:308

Fixes: cff7f95 ("perf tests: Move pmu tests into separate object")
Signed-off-by: Namhyung Kim <namhyung@kernel.org>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Andi Kleen <ak@linux.intel.com>
Cc: Ian Rogers <irogers@google.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Link: http://lore.kernel.org/lkml/20200915031819.386559-12-namhyung@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
koenkooi pushed a commit that referenced this pull request Dec 17, 2020
commit 66d204a upstream.

Very sporadically I had test case btrfs/069 from fstests hanging (for
years, it is not a recent regression), with the following traces in
dmesg/syslog:

  [162301.160628] BTRFS info (device sdc): dev_replace from /dev/sdd (devid 2) to /dev/sdg started
  [162301.181196] BTRFS info (device sdc): scrub: finished on devid 4 with status: 0
  [162301.287162] BTRFS info (device sdc): dev_replace from /dev/sdd (devid 2) to /dev/sdg finished
  [162513.513792] INFO: task btrfs-transacti:1356167 blocked for more than 120 seconds.
  [162513.514318]       Not tainted 5.9.0-rc6-btrfs-next-69 #1
  [162513.514522] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
  [162513.514747] task:btrfs-transacti state:D stack:    0 pid:1356167 ppid:     2 flags:0x00004000
  [162513.514751] Call Trace:
  [162513.514761]  __schedule+0x5ce/0xd00
  [162513.514765]  ? _raw_spin_unlock_irqrestore+0x3c/0x60
  [162513.514771]  schedule+0x46/0xf0
  [162513.514844]  wait_current_trans+0xde/0x140 [btrfs]
  [162513.514850]  ? finish_wait+0x90/0x90
  [162513.514864]  start_transaction+0x37c/0x5f0 [btrfs]
  [162513.514879]  transaction_kthread+0xa4/0x170 [btrfs]
  [162513.514891]  ? btrfs_cleanup_transaction+0x660/0x660 [btrfs]
  [162513.514894]  kthread+0x153/0x170
  [162513.514897]  ? kthread_stop+0x2c0/0x2c0
  [162513.514902]  ret_from_fork+0x22/0x30
  [162513.514916] INFO: task fsstress:1356184 blocked for more than 120 seconds.
  [162513.515192]       Not tainted 5.9.0-rc6-btrfs-next-69 #1
  [162513.515431] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
  [162513.515680] task:fsstress        state:D stack:    0 pid:1356184 ppid:1356177 flags:0x00004000
  [162513.515682] Call Trace:
  [162513.515688]  __schedule+0x5ce/0xd00
  [162513.515691]  ? _raw_spin_unlock_irqrestore+0x3c/0x60
  [162513.515697]  schedule+0x46/0xf0
  [162513.515712]  wait_current_trans+0xde/0x140 [btrfs]
  [162513.515716]  ? finish_wait+0x90/0x90
  [162513.515729]  start_transaction+0x37c/0x5f0 [btrfs]
  [162513.515743]  btrfs_attach_transaction_barrier+0x1f/0x50 [btrfs]
  [162513.515753]  btrfs_sync_fs+0x61/0x1c0 [btrfs]
  [162513.515758]  ? __ia32_sys_fdatasync+0x20/0x20
  [162513.515761]  iterate_supers+0x87/0xf0
  [162513.515765]  ksys_sync+0x60/0xb0
  [162513.515768]  __do_sys_sync+0xa/0x10
  [162513.515771]  do_syscall_64+0x33/0x80
  [162513.515774]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
  [162513.515781] RIP: 0033:0x7f5238f50bd7
  [162513.515782] Code: Bad RIP value.
  [162513.515784] RSP: 002b:00007fff67b978e8 EFLAGS: 00000206 ORIG_RAX: 00000000000000a2
  [162513.515786] RAX: ffffffffffffffda RBX: 000055b1fad2c560 RCX: 00007f5238f50bd7
  [162513.515788] RDX: 00000000ffffffff RSI: 000000000daf0e74 RDI: 000000000000003a
  [162513.515789] RBP: 0000000000000032 R08: 000000000000000a R09: 00007f5239019be0
  [162513.515791] R10: fffffffffffff24f R11: 0000000000000206 R12: 000000000000003a
  [162513.515792] R13: 00007fff67b97950 R14: 00007fff67b97906 R15: 000055b1fad1a340
  [162513.515804] INFO: task fsstress:1356185 blocked for more than 120 seconds.
  [162513.516064]       Not tainted 5.9.0-rc6-btrfs-next-69 #1
  [162513.516329] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
  [162513.516617] task:fsstress        state:D stack:    0 pid:1356185 ppid:1356177 flags:0x00000000
  [162513.516620] Call Trace:
  [162513.516625]  __schedule+0x5ce/0xd00
  [162513.516628]  ? _raw_spin_unlock_irqrestore+0x3c/0x60
  [162513.516634]  schedule+0x46/0xf0
  [162513.516647]  wait_current_trans+0xde/0x140 [btrfs]
  [162513.516650]  ? finish_wait+0x90/0x90
  [162513.516662]  start_transaction+0x4d7/0x5f0 [btrfs]
  [162513.516679]  btrfs_setxattr_trans+0x3c/0x100 [btrfs]
  [162513.516686]  __vfs_setxattr+0x66/0x80
  [162513.516691]  __vfs_setxattr_noperm+0x70/0x200
  [162513.516697]  vfs_setxattr+0x6b/0x120
  [162513.516703]  setxattr+0x125/0x240
  [162513.516709]  ? lock_acquire+0xb1/0x480
  [162513.516712]  ? mnt_want_write+0x20/0x50
  [162513.516721]  ? rcu_read_lock_any_held+0x8e/0xb0
  [162513.516723]  ? preempt_count_add+0x49/0xa0
  [162513.516725]  ? __sb_start_write+0x19b/0x290
  [162513.516727]  ? preempt_count_add+0x49/0xa0
  [162513.516732]  path_setxattr+0xba/0xd0
  [162513.516739]  __x64_sys_setxattr+0x27/0x30
  [162513.516741]  do_syscall_64+0x33/0x80
  [162513.516743]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
  [162513.516745] RIP: 0033:0x7f5238f56d5a
  [162513.516746] Code: Bad RIP value.
  [162513.516748] RSP: 002b:00007fff67b97868 EFLAGS: 00000202 ORIG_RAX: 00000000000000bc
  [162513.516750] RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 00007f5238f56d5a
  [162513.516751] RDX: 000055b1fbb0d5a0 RSI: 00007fff67b978a0 RDI: 000055b1fbb0d470
  [162513.516753] RBP: 000055b1fbb0d5a0 R08: 0000000000000001 R09: 00007fff67b97700
  [162513.516754] R10: 0000000000000004 R11: 0000000000000202 R12: 0000000000000004
  [162513.516756] R13: 0000000000000024 R14: 0000000000000001 R15: 00007fff67b978a0
  [162513.516767] INFO: task fsstress:1356196 blocked for more than 120 seconds.
  [162513.517064]       Not tainted 5.9.0-rc6-btrfs-next-69 #1
  [162513.517365] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
  [162513.517763] task:fsstress        state:D stack:    0 pid:1356196 ppid:1356177 flags:0x00004000
  [162513.517780] Call Trace:
  [162513.517786]  __schedule+0x5ce/0xd00
  [162513.517789]  ? _raw_spin_unlock_irqrestore+0x3c/0x60
  [162513.517796]  schedule+0x46/0xf0
  [162513.517810]  wait_current_trans+0xde/0x140 [btrfs]
  [162513.517814]  ? finish_wait+0x90/0x90
  [162513.517829]  start_transaction+0x37c/0x5f0 [btrfs]
  [162513.517845]  btrfs_attach_transaction_barrier+0x1f/0x50 [btrfs]
  [162513.517857]  btrfs_sync_fs+0x61/0x1c0 [btrfs]
  [162513.517862]  ? __ia32_sys_fdatasync+0x20/0x20
  [162513.517865]  iterate_supers+0x87/0xf0
  [162513.517869]  ksys_sync+0x60/0xb0
  [162513.517872]  __do_sys_sync+0xa/0x10
  [162513.517875]  do_syscall_64+0x33/0x80
  [162513.517878]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
  [162513.517881] RIP: 0033:0x7f5238f50bd7
  [162513.517883] Code: Bad RIP value.
  [162513.517885] RSP: 002b:00007fff67b978e8 EFLAGS: 00000206 ORIG_RAX: 00000000000000a2
  [162513.517887] RAX: ffffffffffffffda RBX: 000055b1fad2c560 RCX: 00007f5238f50bd7
  [162513.517889] RDX: 0000000000000000 RSI: 000000007660add2 RDI: 0000000000000053
  [162513.517891] RBP: 0000000000000032 R08: 0000000000000067 R09: 00007f5239019be0
  [162513.517893] R10: fffffffffffff24f R11: 0000000000000206 R12: 0000000000000053
  [162513.517895] R13: 00007fff67b97950 R14: 00007fff67b97906 R15: 000055b1fad1a340
  [162513.517908] INFO: task fsstress:1356197 blocked for more than 120 seconds.
  [162513.518298]       Not tainted 5.9.0-rc6-btrfs-next-69 #1
  [162513.518672] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
  [162513.519157] task:fsstress        state:D stack:    0 pid:1356197 ppid:1356177 flags:0x00000000
  [162513.519160] Call Trace:
  [162513.519165]  __schedule+0x5ce/0xd00
  [162513.519168]  ? _raw_spin_unlock_irqrestore+0x3c/0x60
  [162513.519174]  schedule+0x46/0xf0
  [162513.519190]  wait_current_trans+0xde/0x140 [btrfs]
  [162513.519193]  ? finish_wait+0x90/0x90
  [162513.519206]  start_transaction+0x4d7/0x5f0 [btrfs]
  [162513.519222]  btrfs_create+0x57/0x200 [btrfs]
  [162513.519230]  lookup_open+0x522/0x650
  [162513.519246]  path_openat+0x2b8/0xa50
  [162513.519270]  do_filp_open+0x91/0x100
  [162513.519275]  ? find_held_lock+0x32/0x90
  [162513.519280]  ? lock_acquired+0x33b/0x470
  [162513.519285]  ? do_raw_spin_unlock+0x4b/0xc0
  [162513.519287]  ? _raw_spin_unlock+0x29/0x40
  [162513.519295]  do_sys_openat2+0x20d/0x2d0
  [162513.519300]  do_sys_open+0x44/0x80
  [162513.519304]  do_syscall_64+0x33/0x80
  [162513.519307]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
  [162513.519309] RIP: 0033:0x7f5238f4a903
  [162513.519310] Code: Bad RIP value.
  [162513.519312] RSP: 002b:00007fff67b97758 EFLAGS: 00000246 ORIG_RAX: 0000000000000055
  [162513.519314] RAX: ffffffffffffffda RBX: 00000000ffffffff RCX: 00007f5238f4a903
  [162513.519316] RDX: 0000000000000000 RSI: 00000000000001b6 RDI: 000055b1fbb0d470
  [162513.519317] RBP: 00007fff67b978c0 R08: 0000000000000001 R09: 0000000000000002
  [162513.519319] R10: 00007fff67b974f7 R11: 0000000000000246 R12: 0000000000000013
  [162513.519320] R13: 00000000000001b6 R14: 00007fff67b97906 R15: 000055b1fad1c620
  [162513.519332] INFO: task btrfs:1356211 blocked for more than 120 seconds.
  [162513.519727]       Not tainted 5.9.0-rc6-btrfs-next-69 #1
  [162513.520115] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
  [162513.520508] task:btrfs           state:D stack:    0 pid:1356211 ppid:1356178 flags:0x00004002
  [162513.520511] Call Trace:
  [162513.520516]  __schedule+0x5ce/0xd00
  [162513.520519]  ? _raw_spin_unlock_irqrestore+0x3c/0x60
  [162513.520525]  schedule+0x46/0xf0
  [162513.520544]  btrfs_scrub_pause+0x11f/0x180 [btrfs]
  [162513.520548]  ? finish_wait+0x90/0x90
  [162513.520562]  btrfs_commit_transaction+0x45a/0xc30 [btrfs]
  [162513.520574]  ? start_transaction+0xe0/0x5f0 [btrfs]
  [162513.520596]  btrfs_dev_replace_finishing+0x6d8/0x711 [btrfs]
  [162513.520619]  btrfs_dev_replace_by_ioctl.cold+0x1cc/0x1fd [btrfs]
  [162513.520639]  btrfs_ioctl+0x2a25/0x36f0 [btrfs]
  [162513.520643]  ? do_sigaction+0xf3/0x240
  [162513.520645]  ? find_held_lock+0x32/0x90
  [162513.520648]  ? do_sigaction+0xf3/0x240
  [162513.520651]  ? lock_acquired+0x33b/0x470
  [162513.520655]  ? _raw_spin_unlock_irq+0x24/0x50
  [162513.520657]  ? lockdep_hardirqs_on+0x7d/0x100
  [162513.520660]  ? _raw_spin_unlock_irq+0x35/0x50
  [162513.520662]  ? do_sigaction+0xf3/0x240
  [162513.520671]  ? __x64_sys_ioctl+0x83/0xb0
  [162513.520672]  __x64_sys_ioctl+0x83/0xb0
  [162513.520677]  do_syscall_64+0x33/0x80
  [162513.520679]  entry_SYSCALL_64_after_hwframe+0x44/0xa9
  [162513.520681] RIP: 0033:0x7fc3cd307d87
  [162513.520682] Code: Bad RIP value.
  [162513.520684] RSP: 002b:00007ffe30a56bb8 EFLAGS: 00000202 ORIG_RAX: 0000000000000010
  [162513.520686] RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 00007fc3cd307d87
  [162513.520687] RDX: 00007ffe30a57a30 RSI: 00000000ca289435 RDI: 0000000000000003
  [162513.520689] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
  [162513.520690] R10: 0000000000000008 R11: 0000000000000202 R12: 0000000000000003
  [162513.520692] R13: 0000557323a212e0 R14: 00007ffe30a5a520 R15: 0000000000000001
  [162513.520703]
		  Showing all locks held in the system:
  [162513.520712] 1 lock held by khungtaskd/54:
  [162513.520713]  #0: ffffffffb40a91a0 (rcu_read_lock){....}-{1:2}, at: debug_show_all_locks+0x15/0x197
  [162513.520728] 1 lock held by in:imklog/596:
  [162513.520729]  #0: ffff8f3f0d781400 (&f->f_pos_lock){+.+.}-{3:3}, at: __fdget_pos+0x4d/0x60
  [162513.520782] 1 lock held by btrfs-transacti/1356167:
  [162513.520784]  #0: ffff8f3d810cc848 (&fs_info->transaction_kthread_mutex){+.+.}-{3:3}, at: transaction_kthread+0x4a/0x170 [btrfs]
  [162513.520798] 1 lock held by btrfs/1356190:
  [162513.520800]  #0: ffff8f3d57644470 (sb_writers#15){.+.+}-{0:0}, at: mnt_want_write_file+0x22/0x60
  [162513.520805] 1 lock held by fsstress/1356184:
  [162513.520806]  #0: ffff8f3d576440e8 (&type->s_umount_key#62){++++}-{3:3}, at: iterate_supers+0x6f/0xf0
  [162513.520811] 3 locks held by fsstress/1356185:
  [162513.520812]  #0: ffff8f3d57644470 (sb_writers#15){.+.+}-{0:0}, at: mnt_want_write+0x20/0x50
  [162513.520815]  #1: ffff8f3d80a650b8 (&type->i_mutex_dir_key#10){++++}-{3:3}, at: vfs_setxattr+0x50/0x120
  [162513.520820]  #2: ffff8f3d57644690 (sb_internal#2){.+.+}-{0:0}, at: start_transaction+0x40e/0x5f0 [btrfs]
  [162513.520833] 1 lock held by fsstress/1356196:
  [162513.520834]  #0: ffff8f3d576440e8 (&type->s_umount_key#62){++++}-{3:3}, at: iterate_supers+0x6f/0xf0
  [162513.520838] 3 locks held by fsstress/1356197:
  [162513.520839]  #0: ffff8f3d57644470 (sb_writers#15){.+.+}-{0:0}, at: mnt_want_write+0x20/0x50
  [162513.520843]  #1: ffff8f3d506465e8 (&type->i_mutex_dir_key#10){++++}-{3:3}, at: path_openat+0x2a7/0xa50
  [162513.520846]  #2: ffff8f3d57644690 (sb_internal#2){.+.+}-{0:0}, at: start_transaction+0x40e/0x5f0 [btrfs]
  [162513.520858] 2 locks held by btrfs/1356211:
  [162513.520859]  #0: ffff8f3d810cde30 (&fs_info->dev_replace.lock_finishing_cancel_unmount){+.+.}-{3:3}, at: btrfs_dev_replace_finishing+0x52/0x711 [btrfs]
  [162513.520877]  #1: ffff8f3d57644690 (sb_internal#2){.+.+}-{0:0}, at: start_transaction+0x40e/0x5f0 [btrfs]

This was weird because the stack traces show that a transaction commit,
triggered by a device replace operation, is blocking trying to pause any
running scrubs but there are no stack traces of blocked tasks doing a
scrub.

After poking around with drgn, I noticed there was a scrub task that was
constantly running and blocking for shorts periods of time:

  >>> t = find_task(prog, 1356190)
  >>> prog.stack_trace(t)
  #0  __schedule+0x5ce/0xcfc
  #1  schedule+0x46/0xe4
  #2  schedule_timeout+0x1df/0x475
  #3  btrfs_reada_wait+0xda/0x132
  #4  scrub_stripe+0x2a8/0x112f
  #5  scrub_chunk+0xcd/0x134
  #6  scrub_enumerate_chunks+0x29e/0x5ee
  #7  btrfs_scrub_dev+0x2d5/0x91b
  #8  btrfs_ioctl+0x7f5/0x36e7
  #9  __x64_sys_ioctl+0x83/0xb0
  torvalds#10 do_syscall_64+0x33/0x77
  torvalds#11 entry_SYSCALL_64+0x7c/0x156

Which corresponds to:

int btrfs_reada_wait(void *handle)
{
    struct reada_control *rc = handle;
    struct btrfs_fs_info *fs_info = rc->fs_info;

    while (atomic_read(&rc->elems)) {
        if (!atomic_read(&fs_info->reada_works_cnt))
            reada_start_machine(fs_info);
        wait_event_timeout(rc->wait, atomic_read(&rc->elems) == 0,
                          (HZ + 9) / 10);
    }
(...)

So the counter "rc->elems" was set to 1 and never decreased to 0, causing
the scrub task to loop forever in that function. Then I used the following
script for drgn to check the readahead requests:

  $ cat dump_reada.py
  import sys
  import drgn
  from drgn import NULL, Object, cast, container_of, execscript, \
      reinterpret, sizeof
  from drgn.helpers.linux import *

  mnt_path = b"/home/fdmanana/btrfs-tests/scratch_1"

  mnt = None
  for mnt in for_each_mount(prog, dst = mnt_path):
      pass

  if mnt is None:
      sys.stderr.write(f'Error: mount point {mnt_path} not found\n')
      sys.exit(1)

  fs_info = cast('struct btrfs_fs_info *', mnt.mnt.mnt_sb.s_fs_info)

  def dump_re(re):
      nzones = re.nzones.value_()
      print(f're at {hex(re.value_())}')
      print(f'\t logical {re.logical.value_()}')
      print(f'\t refcnt {re.refcnt.value_()}')
      print(f'\t nzones {nzones}')
      for i in range(nzones):
          dev = re.zones[i].device
          name = dev.name.str.string_()
          print(f'\t\t dev id {dev.devid.value_()} name {name}')
      print()

  for _, e in radix_tree_for_each(fs_info.reada_tree):
      re = cast('struct reada_extent *', e)
      dump_re(re)

  $ drgn dump_reada.py
  re at 0xffff8f3da9d25ad8
          logical 38928384
          refcnt 1
          nzones 1
                 dev id 0 name b'/dev/sdd'
  $

So there was one readahead extent with a single zone corresponding to the
source device of that last device replace operation logged in dmesg/syslog.
Also the ID of that zone's device was 0 which is a special value set in
the source device of a device replace operation when the operation finishes
(constant BTRFS_DEV_REPLACE_DEVID set at btrfs_dev_replace_finishing()),
confirming again that device /dev/sdd was the source of a device replace
operation.

Normally there should be as many zones in the readahead extent as there are
devices, and I wasn't expecting the extent to be in a block group with a
'single' profile, so I went and confirmed with the following drgn script
that there weren't any single profile block groups:

  $ cat dump_block_groups.py
  import sys
  import drgn
  from drgn import NULL, Object, cast, container_of, execscript, \
      reinterpret, sizeof
  from drgn.helpers.linux import *

  mnt_path = b"/home/fdmanana/btrfs-tests/scratch_1"

  mnt = None
  for mnt in for_each_mount(prog, dst = mnt_path):
      pass

  if mnt is None:
      sys.stderr.write(f'Error: mount point {mnt_path} not found\n')
      sys.exit(1)

  fs_info = cast('struct btrfs_fs_info *', mnt.mnt.mnt_sb.s_fs_info)

  BTRFS_BLOCK_GROUP_DATA = (1 << 0)
  BTRFS_BLOCK_GROUP_SYSTEM = (1 << 1)
  BTRFS_BLOCK_GROUP_METADATA = (1 << 2)
  BTRFS_BLOCK_GROUP_RAID0 = (1 << 3)
  BTRFS_BLOCK_GROUP_RAID1 = (1 << 4)
  BTRFS_BLOCK_GROUP_DUP = (1 << 5)
  BTRFS_BLOCK_GROUP_RAID10 = (1 << 6)
  BTRFS_BLOCK_GROUP_RAID5 = (1 << 7)
  BTRFS_BLOCK_GROUP_RAID6 = (1 << 8)
  BTRFS_BLOCK_GROUP_RAID1C3 = (1 << 9)
  BTRFS_BLOCK_GROUP_RAID1C4 = (1 << 10)

  def bg_flags_string(bg):
      flags = bg.flags.value_()
      ret = ''
      if flags & BTRFS_BLOCK_GROUP_DATA:
          ret = 'data'
      if flags & BTRFS_BLOCK_GROUP_METADATA:
          if len(ret) > 0:
              ret += '|'
          ret += 'meta'
      if flags & BTRFS_BLOCK_GROUP_SYSTEM:
          if len(ret) > 0:
              ret += '|'
          ret += 'system'
      if flags & BTRFS_BLOCK_GROUP_RAID0:
          ret += ' raid0'
      elif flags & BTRFS_BLOCK_GROUP_RAID1:
          ret += ' raid1'
      elif flags & BTRFS_BLOCK_GROUP_DUP:
          ret += ' dup'
      elif flags & BTRFS_BLOCK_GROUP_RAID10:
          ret += ' raid10'
      elif flags & BTRFS_BLOCK_GROUP_RAID5:
          ret += ' raid5'
      elif flags & BTRFS_BLOCK_GROUP_RAID6:
          ret += ' raid6'
      elif flags & BTRFS_BLOCK_GROUP_RAID1C3:
          ret += ' raid1c3'
      elif flags & BTRFS_BLOCK_GROUP_RAID1C4:
          ret += ' raid1c4'
      else:
          ret += ' single'

      return ret

  def dump_bg(bg):
      print()
      print(f'block group at {hex(bg.value_())}')
      print(f'\t start {bg.start.value_()} length {bg.length.value_()}')
      print(f'\t flags {bg.flags.value_()} - {bg_flags_string(bg)}')

  bg_root = fs_info.block_group_cache_tree.address_of_()
  for bg in rbtree_inorder_for_each_entry('struct btrfs_block_group', bg_root, 'cache_node'):
      dump_bg(bg)

  $ drgn dump_block_groups.py

  block group at 0xffff8f3d673b0400
         start 22020096 length 16777216
         flags 258 - system raid6

  block group at 0xffff8f3d53ddb400
         start 38797312 length 536870912
         flags 260 - meta raid6

  block group at 0xffff8f3d5f4d9c00
         start 575668224 length 2147483648
         flags 257 - data raid6

  block group at 0xffff8f3d08189000
         start 2723151872 length 67108864
         flags 258 - system raid6

  block group at 0xffff8f3db70ff000
         start 2790260736 length 1073741824
         flags 260 - meta raid6

  block group at 0xffff8f3d5f4dd800
         start 3864002560 length 67108864
         flags 258 - system raid6

  block group at 0xffff8f3d67037000
         start 3931111424 length 2147483648
         flags 257 - data raid6
  $

So there were only 2 reasons left for having a readahead extent with a
single zone: reada_find_zone(), called when creating a readahead extent,
returned NULL either because we failed to find the corresponding block
group or because a memory allocation failed. With some additional and
custom tracing I figured out that on every further ocurrence of the
problem the block group had just been deleted when we were looping to
create the zones for the readahead extent (at reada_find_extent()), so we
ended up with only one zone in the readahead extent, corresponding to a
device that ends up getting replaced.

So after figuring that out it became obvious why the hang happens:

1) Task A starts a scrub on any device of the filesystem, except for
   device /dev/sdd;

2) Task B starts a device replace with /dev/sdd as the source device;

3) Task A calls btrfs_reada_add() from scrub_stripe() and it is currently
   starting to scrub a stripe from block group X. This call to
   btrfs_reada_add() is the one for the extent tree. When btrfs_reada_add()
   calls reada_add_block(), it passes the logical address of the extent
   tree's root node as its 'logical' argument - a value of 38928384;

4) Task A then enters reada_find_extent(), called from reada_add_block().
   It finds there isn't any existing readahead extent for the logical
   address 38928384, so it proceeds to the path of creating a new one.

   It calls btrfs_map_block() to find out which stripes exist for the block
   group X. On the first iteration of the for loop that iterates over the
   stripes, it finds the stripe for device /dev/sdd, so it creates one
   zone for that device and adds it to the readahead extent. Before getting
   into the second iteration of the loop, the cleanup kthread deletes block
   group X because it was empty. So in the iterations for the remaining
   stripes it does not add more zones to the readahead extent, because the
   calls to reada_find_zone() returned NULL because they couldn't find
   block group X anymore.

   As a result the new readahead extent has a single zone, corresponding to
   the device /dev/sdd;

4) Before task A returns to btrfs_reada_add() and queues the readahead job
   for the readahead work queue, task B finishes the device replace and at
   btrfs_dev_replace_finishing() swaps the device /dev/sdd with the new
   device /dev/sdg;

5) Task A returns to reada_add_block(), which increments the counter
   "->elems" of the reada_control structure allocated at btrfs_reada_add().

   Then it returns back to btrfs_reada_add() and calls
   reada_start_machine(). This queues a job in the readahead work queue to
   run the function reada_start_machine_worker(), which calls
   __reada_start_machine().

   At __reada_start_machine() we take the device list mutex and for each
   device found in the current device list, we call
   reada_start_machine_dev() to start the readahead work. However at this
   point the device /dev/sdd was already freed and is not in the device
   list anymore.

   This means the corresponding readahead for the extent at 38928384 is
   never started, and therefore the "->elems" counter of the reada_control
   structure allocated at btrfs_reada_add() never goes down to 0, causing
   the call to btrfs_reada_wait(), done by the scrub task, to wait forever.

Note that the readahead request can be made either after the device replace
started or before it started, however in pratice it is very unlikely that a
device replace is able to start after a readahead request is made and is
able to complete before the readahead request completes - maybe only on a
very small and nearly empty filesystem.

This hang however is not the only problem we can have with readahead and
device removals. When the readahead extent has other zones other than the
one corresponding to the device that is being removed (either by a device
replace or a device remove operation), we risk having a use-after-free on
the device when dropping the last reference of the readahead extent.

For example if we create a readahead extent with two zones, one for the
device /dev/sdd and one for the device /dev/sde:

1) Before the readahead worker starts, the device /dev/sdd is removed,
   and the corresponding btrfs_device structure is freed. However the
   readahead extent still has the zone pointing to the device structure;

2) When the readahead worker starts, it only finds device /dev/sde in the
   current device list of the filesystem;

3) It starts the readahead work, at reada_start_machine_dev(), using the
   device /dev/sde;

4) Then when it finishes reading the extent from device /dev/sde, it calls
   __readahead_hook() which ends up dropping the last reference on the
   readahead extent through the last call to reada_extent_put();

5) At reada_extent_put() it iterates over each zone of the readahead extent
   and attempts to delete an element from the device's 'reada_extents'
   radix tree, resulting in a use-after-free, as the device pointer of the
   zone for /dev/sdd is now stale. We can also access the device after
   dropping the last reference of a zone, through reada_zone_release(),
   also called by reada_extent_put().

And a device remove suffers the same problem, however since it shrinks the
device size down to zero before removing the device, it is very unlikely to
still have readahead requests not completed by the time we free the device,
the only possibility is if the device has a very little space allocated.

While the hang problem is exclusive to scrub, since it is currently the
only user of btrfs_reada_add() and btrfs_reada_wait(), the use-after-free
problem affects any path that triggers readhead, which includes
btree_readahead_hook() and __readahead_hook() (a readahead worker can
trigger readahed for the children of a node) for example - any path that
ends up calling reada_add_block() can trigger the use-after-free after a
device is removed.

So fix this by waiting for any readahead requests for a device to complete
before removing a device, ensuring that while waiting for existing ones no
new ones can be made.

This problem has been around for a very long time - the readahead code was
added in 2011, device remove exists since 2008 and device replace was
introduced in 2013, hard to pick a specific commit for a git Fixes tag.

CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
koenkooi pushed a commit that referenced this pull request Dec 17, 2020
commit e2b2e43 upstream.

After upgrading kernel to version 5.9.x the driver was not
working anymore showing the following kernel trace:

...
mt7621-pci 1e140000.pcie: resource collision:
[mem 0x60000000-0x6fffffff] conflicts with pcie@1e140000 [mem 0x60000000-0x6fffffff]
------------[ cut here ]------------
WARNING: CPU: 2 PID: 73 at kernel/resource.c:1400
devm_request_resource+0xfc/0x10c
Modules linked in:
CPU: 2 PID: 73 Comm: kworker/2:1 Not tainted 5.9.2 #0
Workqueue: events deferred_probe_work_func
Stack : 00000000 81590000 807d0a1c 808a0000 8fd49080
        807d0000 00000009 808ac820
        00000001 808338d0 7fff0001 800839dc 00000049
        00000001 8fe51b00 367204ab
        00000000 00000000 807d0a1c 807c0000 00000001
        80082358 8fe50000 00559000
        00000000 8fe519f1 ffffffff 00000005 00000000
        00000001 00000000 807d0000
        00000009 808ac820 00000001 808338d0 00000001
        803bf1b0 00000008 81390008

Call Trace:
[<8000d018>] show_stack+0x30/0x100
[<8032e66c>] dump_stack+0xa4/0xd4
[<8002db1c>] __warn+0xc0/0x134
[<8002dbec>] warn_slowpath_fmt+0x5c/0xac
[<80033b34>] devm_request_resource+0xfc/0x10c
[<80365ff8>] devm_request_pci_bus_resources+0x58/0xdc
[<8048e13c>] mt7621_pci_probe+0x8dc/0xe48
[<803d2140>] platform_drv_probe+0x40/0x94
[<803cfd94>] really_probe+0x108/0x4ec
[<803cd958>] bus_for_each_drv+0x70/0xb0
[<803d0388>] __device_attach+0xec/0x164
[<803cec8c>] bus_probe_device+0xa4/0xc0
[<803cf1c4>] deferred_probe_work_func+0x80/0xc4
[<80048444>] process_one_work+0x260/0x510
[<80048a4c>] worker_thread+0x358/0x5cc
[<8004f7d0>] kthread+0x134/0x13c
[<80007478>] ret_from_kernel_thread+0x14/0x1c
---[ end trace a9dd2e37537510d3 ]---
mt7621-pci 1e140000.pcie: Error requesting resources
mt7621-pci: probe of 1e140000.pcie failed with error -16
...

With commit 669cbc7 ("PCI: Move DT resource setup into
devm_pci_alloc_host_bridge()"), the DT 'ranges' is parsed and populated
into resources when the host bridge is allocated. The resources are
requested as well, but that happens a 2nd time for this driver in
mt7621_pcie_request_resources(). Hence we should avoid this second
request.

Also, the bus ranges was also populated by default, so we can remove
it from mt7621_pcie_request_resources() to avoid the following trace
if we don't avoid it:

pci_bus 0000:00: busn_res: can not insert [bus 00-ff]
under domain [bus 00-ff] (conflicts with (null) [bus 00-ff])

Function 'mt7621_pcie_request_resources' has been renamed into
'mt7621_pcie_add_resources' which now is a more accurate name
for this function.

Cc: stable@vger.kernel.org #5.9.x-
Signed-off-by: Sergio Paracuellos <sergio.paracuellos@gmail.com>
Link: https://lore.kernel.org/r/20201102202515.19073-1-sergio.paracuellos@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
koenkooi pushed a commit that referenced this pull request Dec 17, 2020
commit de9ac0a upstream.

cifs_reconnect needs to be called only from demultiplex thread.
skip cifs_reconnect in offload thread. So, cifs_reconnect will be
called by demultiplex thread in subsequent request.

These patches address a problem found during decryption offload:
     CIFS: VFS: trying to dequeue a deleted mid
that can cause a refcount use after free:

[ 1271.389453] Workqueue: smb3decryptd smb2_decrypt_offload [cifs]
[ 1271.389456] RIP: 0010:refcount_warn_saturate+0xae/0xf0
[ 1271.389457] Code: fa 1d 6a 01 01 e8 c7 44 b1 ff 0f 0b 5d c3 80 3d e7 1d 6a 01 00 75 91 48 c7 c7 d8 be 1d a2 c6 05 d7 1d 6a 01 01 e8 a7 44 b1 ff <0f> 0b 5d c3 80 3d c5 1d 6a 01 00 0f 85 6d ff ff ff 48 c7 c7 30 bf
[ 1271.389458] RSP: 0018:ffffa4cdc1f87e30 EFLAGS: 00010286
[ 1271.389458] RAX: 0000000000000000 RBX: ffff9974d2809f00 RCX: ffff9974df898cc8
[ 1271.389459] RDX: 00000000ffffffd8 RSI: 0000000000000027 RDI: ffff9974df898cc0
[ 1271.389460] RBP: ffffa4cdc1f87e30 R08: 0000000000000004 R09: 00000000000002c0
[ 1271.389460] R10: 0000000000000000 R11: 0000000000000001 R12: ffff9974b7fdb5c0
[ 1271.389461] R13: ffff9974d2809f00 R14: ffff9974ccea0a80 R15: ffff99748e60db80
[ 1271.389462] FS:  0000000000000000(0000) GS:ffff9974df880000(0000) knlGS:0000000000000000
[ 1271.389462] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 1271.389463] CR2: 000055c60f344fe4 CR3: 0000001031a3c002 CR4: 00000000003706e0
[ 1271.389465] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 1271.389465] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 1271.389466] Call Trace:
[ 1271.389483]  cifs_mid_q_entry_release+0xce/0x110 [cifs]
[ 1271.389499]  smb2_decrypt_offload+0xa9/0x1c0 [cifs]
[ 1271.389501]  process_one_work+0x1e8/0x3b0
[ 1271.389503]  worker_thread+0x50/0x370
[ 1271.389504]  kthread+0x12f/0x150
[ 1271.389506]  ? process_one_work+0x3b0/0x3b0
[ 1271.389507]  ? __kthread_bind_mask+0x70/0x70
[ 1271.389509]  ret_from_fork+0x22/0x30

Signed-off-by: Rohith Surabattula <rohiths@microsoft.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
CC: Stable <stable@vger.kernel.org> #5.4+
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
koenkooi pushed a commit that referenced this pull request Dec 17, 2020
commit ac873aa upstream.

When reconnect happens Mid queue can be corrupted when both
demultiplex and offload thread try to dequeue the MID from the
pending list.

These patches address a problem found during decryption offload:
         CIFS: VFS: trying to dequeue a deleted mid
that could cause a refcount use after free:
         Workqueue: smb3decryptd smb2_decrypt_offload [cifs]

Signed-off-by: Rohith Surabattula <rohiths@microsoft.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
CC: Stable <stable@vger.kernel.org> #5.4+
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
koenkooi pushed a commit that referenced this pull request Dec 17, 2020
commit 1254100 upstream.

Mid callback needs to be called only when valid data is
read into pages.

These patches address a problem found during decryption offload:
      CIFS: VFS: trying to dequeue a deleted mid
that could cause a refcount use after free:
      Workqueue: smb3decryptd smb2_decrypt_offload [cifs]

Signed-off-by: Rohith Surabattula <rohiths@microsoft.com>
Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com>
CC: Stable <stable@vger.kernel.org> #5.4+
Signed-off-by: Steve French <stfrench@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
koenkooi pushed a commit that referenced this pull request Dec 17, 2020
[ Upstream commit e773ca7 ]

Actually, burst size is equal to '1 << desc->rqcfg.brst_size'.
we should use burst size, not desc->rqcfg.brst_size.

dma memcpy performance on Rockchip RV1126
@ 1512MHz A7, 1056MHz LPDDR3, 200MHz DMA:

dmatest:

/# echo dma0chan0 > /sys/module/dmatest/parameters/channel
/# echo 4194304 > /sys/module/dmatest/parameters/test_buf_size
/# echo 8 > /sys/module/dmatest/parameters/iterations
/# echo y > /sys/module/dmatest/parameters/norandom
/# echo y > /sys/module/dmatest/parameters/verbose
/# echo 1 > /sys/module/dmatest/parameters/run

dmatest: dma0chan0-copy0: result #1: 'test passed' with src_off=0x0 dst_off=0x0 len=0x400000
dmatest: dma0chan0-copy0: result #2: 'test passed' with src_off=0x0 dst_off=0x0 len=0x400000
dmatest: dma0chan0-copy0: result #3: 'test passed' with src_off=0x0 dst_off=0x0 len=0x400000
dmatest: dma0chan0-copy0: result #4: 'test passed' with src_off=0x0 dst_off=0x0 len=0x400000
dmatest: dma0chan0-copy0: result #5: 'test passed' with src_off=0x0 dst_off=0x0 len=0x400000
dmatest: dma0chan0-copy0: result #6: 'test passed' with src_off=0x0 dst_off=0x0 len=0x400000
dmatest: dma0chan0-copy0: result #7: 'test passed' with src_off=0x0 dst_off=0x0 len=0x400000
dmatest: dma0chan0-copy0: result #8: 'test passed' with src_off=0x0 dst_off=0x0 len=0x400000

Before:

  dmatest: dma0chan0-copy0: summary 8 tests, 0 failures 48 iops 200338 KB/s (0)

After this patch:

  dmatest: dma0chan0-copy0: summary 8 tests, 0 failures 179 iops 734873 KB/s (0)

After this patch and increase dma clk to 400MHz:

  dmatest: dma0chan0-copy0: summary 8 tests, 0 failures 259 iops 1062929 KB/s (0)

Signed-off-by: Sugar Zhang <sugar.zhang@rock-chips.com>
Link: https://lore.kernel.org/r/1605326106-55681-1-git-send-email-sugar.zhang@rock-chips.com
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
This pull request was closed.
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