[ASan] Add sleep_before_init flag

[yln]

Summary

Also do a little bit of refactoring instead of just copy&paste.

compiler-rt/lib/asan/asan_flags.inc

ASAN_FLAG(
     int, sleep_before_dying, 0,
     "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(
+    int, sleep_before_init, 0,
+    "Number of seconds to sleep before AddressSanitizer starts initializing. "
+    "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.*.")
 ASAN_FLAG(bool, unmap_shadow_on_exit, false,
           "If set, explicitly unmaps the (huge) shadow at exit.")
 ASAN_FLAG(bool, protect_shadow_gap, true, "If set, mprotect the shadow gap")
 ASAN_FLAG(bool, print_stats, false,
           "Print various statistics after printing an error message or if "

compiler-rt/lib/asan/asan_rtl.cpp

static void AsanDie() {
   if (atomic_fetch_add(&num_calls, 1, memory_order_relaxed) != 0) {
     // Don't die twice - run a busy loop.
     while (1) {
       internal_sched_yield();
     }
   }
   if (common_flags()->print_module_map >= 1)
     DumpProcessMap();
-  if (flags()->sleep_before_dying) {
-    Report("Sleeping for %d second(s)\n", flags()->sleep_before_dying);
-    SleepForSeconds(flags()->sleep_before_dying);
-  }
+
+  WaitForDebugger(flags()->sleep_before_dying, "before dying");
+
   if (flags()->unmap_shadow_on_exit) {
     if (kMidMemBeg) {
       UnmapOrDie((void*)kLowShadowBeg, kMidMemBeg - kLowShadowBeg);
       UnmapOrDie((void*)kMidMemEnd, kHighShadowEnd - kMidMemEnd);
     } else {
       if (kHighShadowEnd)
         UnmapOrDie((void*)kLowShadowBeg, kHighShadowEnd - kLowShadowBeg);
     }
static void AsanInitInternal() {
   asan_init_is_running = true;
 
   CacheBinaryName();
 
   // Initialize flags. This must be done early, because most of the
   // initialization steps look at flags().
   InitializeFlags();
 
+  WaitForDebugger(flags()->sleep_before_init, "before init");
+
   // Stop performing init at this point if we are being loaded via
   // dlopen() and the platform supports it.
   if (SANITIZER_SUPPORTS_INIT_FOR_DLOPEN && UNLIKELY(HandleDlopenInit())) {
     asan_init_is_running = false;
     VReport(1, "AddressSanitizer init is being performed for dlopen().\n");
     return;
   }
 
if (CAN_SANITIZE_LEAKS) {
     __lsan::ScopedInterceptorDisabler disabler;
     Symbolizer::LateInitialize();
   } else {
     Symbolizer::LateInitialize();
   }
 
   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);
-  }
+  WaitForDebugger(flags()->sleep_after_init, "after init");
 }
 
 // Initialize as requested from some part of ASan runtime library (interceptors,
 // allocator, etc).
 void AsanInitFromRtl() {
   AsanInitInternal();
 }
 

compiler-rt/lib/sanitizer_common/sanitizer_common.h

 void SetSandboxingCallback(void (*f)());
 
 void InitializeCoverage(bool enabled, const char *coverage_dir);
 
 void InitTlsSize();
 uptr GetTlsSize();
 
 // Other
+void WaitForDebugger(unsigned seconds, const char *label);
 void SleepForSeconds(unsigned seconds);
 void SleepForMillis(unsigned millis);
 u64 NanoTime();
 u64 MonotonicNanoTime();
 int Atexit(void (*function)(void));
 bool TemplateMatch(const char *templ, const char *str);
 
 // Exit

compiler-rt/lib/sanitizer_common/sanitizer_common.cpp

 void internal_sleep(unsigned seconds) {
   internal_usleep((u64)seconds * 1000 * 1000);
 }
 void SleepForSeconds(unsigned seconds) {
   internal_usleep((u64)seconds * 1000 * 1000);
 }
 void SleepForMillis(unsigned millis) { internal_usleep((u64)millis * 1000); }
 
+void WaitForDebugger(unsigned seconds, const char *label) {
+  if (seconds) {
+    Report("Sleeping for %u second(s) %s\n", seconds, label);
+    SleepForSeconds(seconds);
+  }
+}
+
 } // namespace __sanitizer
 
 using namespace __sanitizer;
 
 extern "C" {
 SANITIZER_INTERFACE_WEAK_DEF(void, __sanitizer_report_error_summary,
                              const char *error_summary) {
   Printf("%s\n", error_summary);

compiler-rt/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];
-}

compiler-rt/test/asan/TestCases/sleep_before_dying.c

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

compiler-rt/test/asan/TestCases/sleep_for_debugger.c

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