[PATCH] D20047: [sanitizer] Break infinite recursion in case of recursive failed CHECKs

[Kuba Brecka via llvm-commits]

kubabrecka created this revision.
kubabrecka added reviewers: dvyukov, samsonov, glider, kcc, aizatsky.
kubabrecka added subscribers: llvm-commits, zaks.anna, dcoughlin.
kubabrecka added a project: Sanitizers.
Herald added a subscriber: kubabrecka.

While debugging ASan and TSan, I sometimes get a recursion during a failed CHECK processing.  `CheckFailed` can call a lot of code (printing, unwinding a stack trace, symbolicating, ...) and this can fail another CHECK.  This means I sometimes see a crash due to a infinite recursion stack overflow.  Let's stop after 10 failed CHECKs and just kill the process immediately.  I also added a `Sleep(2)` call before the trap, so that other threads still get a chance to print their failed CHECKs.

http://reviews.llvm.org/D20047

Files:
  lib/sanitizer_common/sanitizer_common.cc

Index: lib/sanitizer_common/sanitizer_common.cc
===================================================================
--- lib/sanitizer_common/sanitizer_common.cc
+++ lib/sanitizer_common/sanitizer_common.cc
@@ -153,8 +153,16 @@
   CheckFailedCallback = callback;
 }
 
+const int kSecondsToSleepWhenRecursiveCheckFailed = 2;
+
 void NORETURN CheckFailed(const char *file, int line, const char *cond,
                           u64 v1, u64 v2) {
+  static atomic_uint32_t num_calls;
+  if (atomic_fetch_add(&num_calls, 1, memory_order_relaxed) > 10) {
+    SleepForSeconds(kSecondsToSleepWhenRecursiveCheckFailed);
+    Trap();
+  }
+
   if (CheckFailedCallback) {
     CheckFailedCallback(file, line, cond, v1, v2);
   }


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