Add new ASAN_OPTION: sleep_after_init.

[marxin]

Summary

As mentioned in https://github.com/google/sanitizers/issues/834, suggested option can be handy for debugging.

[kcc]

code LGTM, please add a test (sleep for 1 second, verify that "Sleeping for 1 second(s)" is printed

[marxin]

In D35409#809729, @kcc wrote:

code LGTM, please add a test (sleep for 1 second, verify that "Sleeping for 1 second(s)" is printed

Sure. May I please ask you for advise about how to run a single test?

[kcc]

Take a look at test/asan/TestCases/sleep_before_dying.c,
you will need a similar one.

Then, run 'ninja check-asan'.
It should fail w/o your change and pass with your change.

[marxin]

Running:

$ make check

I see:

[ 98%] Built target clang
/usr/lib64/gcc/x86_64-suse-linux/7/../../../../x86_64-suse-linux/bin/ld: skipping incompatible /usr/lib64/gcc/x86_64-suse-linux/7/../../../libm.so when searching for -lm
/usr/lib64/gcc/x86_64-suse-linux/7/../../../../x86_64-suse-linux/bin/ld: skipping incompatible /usr/lib64/gcc/x86_64-suse-linux/7/../../../libpthread.so when searching for -lpthread
/usr/lib64/gcc/x86_64-suse-linux/7/../../../../x86_64-suse-linux/bin/ld: skipping incompatible /usr/lib64/gcc/x86_64-suse-linux/7/../../../librt.so when searching for -lrt
/usr/lib64/gcc/x86_64-suse-linux/7/../../../../x86_64-suse-linux/bin/ld: skipping incompatible /usr/lib64/gcc/x86_64-suse-linux/7/../../../libm.so when searching for -lm
/usr/lib64/gcc/x86_64-suse-linux/7/../../../../x86_64-suse-linux/bin/ld: skipping incompatible /usr/lib64/gcc/x86_64-suse-linux/7/../../../libdl.so when searching for -ldl
/usr/lib64/gcc/x86_64-suse-linux/7/../../../../x86_64-suse-linux/bin/ld: skipping incompatible /usr/lib64/gcc/x86_64-suse-linux/7/../../../libc.so when searching for -lc
/usr/lib64/gcc/x86_64-suse-linux/7/../../../../x86_64-suse-linux/bin/ld: i386:x86-64 architecture of input file `/usr/lib64/gcc/x86_64-suse-linux/7/../../../crt1.o' is incompatible with i386 output
/usr/lib64/gcc/x86_64-suse-linux/7/../../../../x86_64-suse-linux/bin/ld: i386:x86-64 architecture of input file `/usr/lib64/gcc/x86_64-suse-linux/7/../../../crti.o' is incompatible with i386 output
/usr/lib64/gcc/x86_64-suse-linux/7/../../../../x86_64-suse-linux/bin/ld: i386:x86-64 architecture of input file `/usr/lib64/gcc/x86_64-suse-linux/7/../../../crtn.o' is incompatible with i386 output
/usr/lib64/gcc/x86_64-suse-linux/7/../../../../x86_64-suse-linux/bin/ld: /usr/lib64/gcc/x86_64-suse-linux/7/../../../crt1.o: file class ELFCLASS64 incompatible with ELFCLASS32
/usr/lib64/gcc/x86_64-suse-linux/7/../../../../x86_64-suse-linux/bin/ld: final link failed: File in wrong format
clang-6.0: error: linker command failed with exit code 1 (use -v to see invocation)
make[3]: * [projects/compiler-rt/lib/asan/tests/CMakeFiles/Asan-i386-inline-Test.dir/build.make:67: projects/compiler-rt/lib/asan/tests/CMakeFiles/Asan-i386-inline-Test] Error 1
make[2]: * [CMakeFiles/Makefile2:20864: projects/compiler-rt/lib/asan/tests/CMakeFiles/Asan-i386-inline-Test.dir/all] Error 2
make[1]: *** [CMakeFiles/Makefile2:24869: projects/compiler-rt/test/asan/CMakeFiles/check-asan.dir/rule] Error 2

[marxin]

So the problem with test-suite will be related to openSUSE, I've already create bug for that.

[marxin]

Update versioin where I added test-case. It's verified that it passes regression tests.

[kcc]

LGTM
You don't have commit access, do you?
I'll land it later today, unless someone else beats me to it.

[marxin]

Yes, thanks for review and please install the patch.

lib/asan/asan_flags.inc

     "Number of seconds to sleep between printing an error report and "
     "terminating the program. Useful for debugging purposes (e.g. when one "
     "needs to attach gdb).")
+ASAN_FLAG(
+    int, sleep_after_init, 0,
+    "Number of seconds to sleep after AddressSanitizer is initialized. "
+    "Useful for debugging purposes (e.g. when one needs to attach gdb).")
 ASAN_FLAG(bool, check_malloc_usable_size, true,
           "Allows the users to work around the bug in Nvidia drivers prior to "
           "295.*.")

lib/asan/asan_rtl.cc

   }
 
   VReport(1, "AddressSanitizer Init done\n");
+
+  if (flags()->sleep_after_init) {
+    Report("Sleeping for %d second(s)\n", flags()->sleep_after_init);
+    SleepForSeconds(flags()->sleep_after_init);
+  }
 }
 
 // Initialize as requested from some part of ASan runtime library (interceptors,

test/asan/TestCases/sleep_after_init.c

+// RUN: %clang_asan -O2 %s -o %t
+// RUN: %env_asan_opts=sleep_after_init=1 not %run %t 2>&1 | FileCheck %s
+
+#include <stdlib.h>
+int main() {
+  // CHECK: Sleeping for 1 second
+  char *x = (char*)malloc(10 * sizeof(char));
+  free(x);
+  return x[5];
+}