From 817cf5821deb34c232366f4063a9a6fe02f9ca5a Mon Sep 17 00:00:00 2001 From: Jeff Hostetler Date: Wed, 18 Sep 2019 10:35:45 -0400 Subject: [PATCH] sub-process: do not borrow cmd pointer from caller Teach subprocess_start() to use a copy of the passed `cmd` string rather than borrowing the buffer from the caller. Some callers of subprocess_start() pass the value returned from find_hook() which points to a static buffer and therefore is only good until the next call to find_hook(). This could cause problems for the long-running background processes managed by sub-process.c where later calls to subprocess_find_entry() to get an existing process will fail. This could cause more than 1 long-running process to be created. TODO Need to confirm, but if only read_object_hook() uses TODO subprocess_start() in this manner, we could drop this TODO commit when we drop support for read_object_hook(). Signed-off-by: Jeff Hostetler --- sub-process.c | 9 ++++++++- 1 file changed, 8 insertions(+), 1 deletion(-) diff --git a/sub-process.c b/sub-process.c index 1daf5a975254b9..3327b1e4396c0a 100644 --- a/sub-process.c +++ b/sub-process.c @@ -81,7 +81,12 @@ int subprocess_start(struct hashmap *hashmap, struct subprocess_entry *entry, co int err; struct child_process *process; - entry->cmd = cmd; + // BUGBUG most callers to subprocess_start() pass in "cmd" the value + // BUGBUG of find_hook() which returns a static buffer (that's only + // BUGBUG good until the next call to find_hook()). + // BUGFIX Defer assignment until we copy the string in our argv. + // entry->cmd = cmd; + process = &entry->process; child_process_init(process); @@ -93,6 +98,8 @@ int subprocess_start(struct hashmap *hashmap, struct subprocess_entry *entry, co process->clean_on_exit_handler = subprocess_exit_handler; process->trace2_child_class = "subprocess"; + entry->cmd = process->args.v[0]; + err = start_command(process); if (err) { error("cannot fork to run subprocess '%s'", cmd);