added strace exclude filter feature

tests/Makefile

@@ -136,6 +136,8 @@ endif
 
 DIRS += appenv
 DIRS += go
+DIRS += strace
+
 
 .PHONY: $(DIRS)
 

tests/strace/.gitignore

@@ -0,0 +1,7 @@
+1
+2
+3
+test1.txt
+test2.txt
+test3.txt
+test4.txt

tests/strace/Makefile

@@ -0,0 +1,50 @@
+TOP=$(abspath ../..)
+include $(TOP)/defs.mak
+
+APPDIR = appdir
+CFLAGS = -fPIC
+LDFLAGS = -Wl,-rpath=$(MUSL_LIB)
+
+all:
+	$(MAKE) myst
+	$(MAKE) rootfs
+
+rootfs: strace.c
+	mkdir -p $(APPDIR)/bin
+	$(CC) $(CFLAGS) -o $(APPDIR)/bin/strace strace.c $(LDFLAGS)
+	$(MYST) mkcpio $(APPDIR) rootfs
+
+OPTS =
+
+ifdef PERF
+OPTS += --perf
+endif
+
+OPTS += --thread-stack-size=1048576
+
+tests: all test1 test2 test3 test4
+	echo " === passed test strace"
+
+test1:
+	-$(MYST_EXEC) rootfs /bin/strace --strace-filter=SYS_invali $(OPTS) 2> test1.txt || $(RUNTEST) diff test1.txt test1.expected.txt
+	echo "=== test1 passed"
+
+test2:
+	-$(MYST_EXEC) rootfs /bin/strace --strace-filter=SYS_mmap --strace-exclude-filter=SYS_ioctl $(OPTS) 2> test2.txt || $(RUNTEST) diff test2.txt test2.expected.txt
+	echo "=== test2 passed"
+
+test3:
+	$(MYST_EXEC) rootfs /bin/strace --strace-filter=SYS_close $(OPTS) 2> test3.txt
+	cat test3.txt | grep "SYS_" > 1 && cat test3.txt | grep "SYS_close" > 2 && $(RUNTEST) diff 1 2
+	echo "=== test3 passed"
+
+test4:
+	$(MYST_EXEC) rootfs /bin/strace --strace-exclude-filter=SYS_open $(OPTS) 2> test4.txt
+	cat test4.txt | grep -v "SYS_open" > 3 && $(RUNTEST) diff 3 test4.txt
+	echo "=== test4 passed"
+
+myst:
+	$(MAKE) -C $(TOP)/tools/myst
+
+clean:
+	rm -rf $(APPDIR) rootfs export ramfs 1 2 3 test1.txt text2.txt test3.txt test4.txt

tests/strace/strace.c

@@ -0,0 +1,25 @@
+// Copyright (c) Microsoft Corporation.
+// Licensed under the MIT License.
+
+#include <assert.h>
+#include <limits.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+void foofoo()
+{
+}
+
+int main(int argc, const char* argv[])
+{
+    char buf[PATH_MAX];
+
+    foofoo();
+
+    getcwd(buf, sizeof(buf));
+    assert(strcmp(buf, "/") == 0);
+
+    return 0;
+}

tests/strace/test1.expected.txt

@@ -0,0 +1,2 @@
+Unknown syscall SYS_invali specified in --strace-filter or --strace-exclude-filter 
+Aborted (core dumped)

tests/strace/test2.expected.txt

@@ -0,0 +1,2 @@
+Cannot specify both --strace-filter and --strace-exclude-filter
+Aborted (core dumped)

tools/myst/host/strace.c

@@ -8,6 +8,49 @@
 #include <myst/strings.h>
 #include <myst/syscall.h>
 
+int myst_set_strace_filter(
+    int num_tokens,
+    char** tokens,
+    myst_strace_config_t* strace_config,
+    bool include)
+{
+    for (size_t i = 0; i < MYST_MAX_SYSCALLS; ++i)
+    {
+        strace_config->trace[i] = !include;
+    }
+
+    for (size_t i = 0; i < num_tokens; ++i)
+    {
+        const char* name = tokens[i];
+        long num = myst_syscall_num(name);
+        if (num >= 0)
+        {
+            if (num < MYST_MAX_SYSCALLS)
+                strace_config->trace[num] = include;
+            else
+            {
+                fprintf(
+                    stderr,
+                    "Syscall %s exceeds trace array. Fix "
+                    "myst_syscall_config_t\n",
+                    name);
+                abort();
+            }
+        }
+        else
+        {
+            fprintf(
+                stderr,
+                "Unknown syscall %s specified in --strace-filter or "
+                "--strace-exclude-filter \n",
+                name);
+            abort();
+        }
+    }
+    strace_config->filter = 1;
+    return 0;
+}
+
 int myst_parse_strace_config(
     int* argc,
     const char** argv,
@@ -17,6 +60,7 @@ int myst_parse_strace_config(
     const char* filter = NULL;
     char** tokens = NULL;
     size_t num_tokens = 0;
+    bool filter_flag = 0;
 
     if (cli_getopt(argc, argv, "--strace-failing", NULL) == 0)
     {
@@ -31,35 +75,33 @@ int myst_parse_strace_config(
             fprintf(stderr, "Invalid strace-filter '%s' specified.\n", filter);
             abort();
         }
-        for (size_t i = 0; i < num_tokens; ++i)
+
+        ret = myst_set_strace_filter(num_tokens, tokens, strace_config, 1);
+        filter_flag = true;
+    }
+
+    if (cli_getopt(argc, argv, "--strace-exclude-filter", &filter) == 0 &&
+        filter)
+    {
+        if (filter_flag)
         {
-            const char* name = tokens[i];
-            long num = myst_syscall_num(name);
-            if (num >= 0)
-            {
-                if (num < MYST_MAX_SYSCALLS)
-                    strace_config->trace[num] = 1;
-                else
-                {
-                    fprintf(
-                        stderr,
-                        "Syscall %s exceeds trace array. Fix "
-                        "myst_syscall_config_t\n",
-                        name);
-                    abort();
-                }
-            }
-            else
-            {
-                fprintf(
-                    stderr,
-                    "Unknown syscall %s specified in --strace=filter\n",
-                    name);
-                abort();
-            }
+            fprintf(
+                stderr,
+                "Cannot specify both --strace-filter and "
+                "--strace-exclude-filter\n");
+            abort();
         }
-        strace_config->filter = 1;
-        ret = 0;
+
+        if (myst_strsplit(filter, ":", &tokens, &num_tokens) != 0)
+        {
+            fprintf(
+                stderr,
+                "Invalid strace-exclude-filter '%s' specified.\n",
+                filter);
+            abort();
+        }
+
+        ret = myst_set_strace_filter(num_tokens, tokens, strace_config, 0);
     }
 
     if (tokens)