[rtsan] Add statistics for suppression count

[cjappl]

I thought this could be a good debugging tool, if someone passed a suppression file and wondered why their binary wasn't dying.

[llvmbot]

@llvm/pr-subscribers-compiler-rt-sanitizer

Author: Chris Apple (cjappl)

Changes

---

Full diff: https://github.com/llvm/llvm-project/pull/112718.diff

8 Files Affected:

• (modified) compiler-rt/lib/rtsan/rtsan_assertions.h (+7-2)
• (modified) compiler-rt/lib/rtsan/rtsan_flags.h (+2)
• (modified) compiler-rt/lib/rtsan/rtsan_stats.cpp (+13)
• (modified) compiler-rt/lib/rtsan/rtsan_stats.h (+1)
• (modified) compiler-rt/lib/rtsan/rtsan_suppressions.cpp (+1-1)
• (modified) compiler-rt/test/rtsan/exit_stats.cpp (+11)
• (added) compiler-rt/test/rtsan/exit_stats.cpp.supp (+1)
• (modified) compiler-rt/test/rtsan/stack_suppressions.cpp (+4-1)

diff --git a/compiler-rt/lib/rtsan/rtsan_assertions.h b/compiler-rt/lib/rtsan/rtsan_assertions.h
index 927b32e03cf026..28a272b6462372 100644
--- a/compiler-rt/lib/rtsan/rtsan_assertions.h
+++ b/compiler-rt/lib/rtsan/rtsan_assertions.h
@@ -15,6 +15,7 @@
 #include "rtsan/rtsan.h"
 #include "rtsan/rtsan_context.h"
 #include "rtsan/rtsan_diagnostics.h"
+#include "rtsan/rtsan_stats.h"
 #include "rtsan/rtsan_suppressions.h"
 
 #include "sanitizer_common/sanitizer_stacktrace.h"
@@ -28,8 +29,10 @@ void ExpectNotRealtime(Context &context, const DiagnosticsInfo &info,
   if (context.InRealtimeContext() && !context.IsBypassed()) {
     ScopedBypass sb{context};
 
-    if (IsFunctionSuppressed(info.func_name))
+    if (IsFunctionSuppressed(info.func_name)) {
+      IncrementSuppressedCount();
       return;
+    }
 
     __sanitizer::BufferedStackTrace stack;
 
@@ -38,8 +41,10 @@ void ExpectNotRealtime(Context &context, const DiagnosticsInfo &info,
     stack.Unwind(info.pc, info.bp, nullptr,
                  __sanitizer::common_flags()->fast_unwind_on_fatal);
 
-    if (IsStackTraceSuppressed(stack))
+    if (IsStackTraceSuppressed(stack)) {
+      IncrementSuppressedCount();
       return;
+    }
 
     OnViolation(stack, info);
   }
diff --git a/compiler-rt/lib/rtsan/rtsan_flags.h b/compiler-rt/lib/rtsan/rtsan_flags.h
index 29025c29b6fc2a..f46e04933fa528 100644
--- a/compiler-rt/lib/rtsan/rtsan_flags.h
+++ b/compiler-rt/lib/rtsan/rtsan_flags.h
@@ -18,6 +18,8 @@ struct Flags {
   Type Name{DefaultValue};
 #include "rtsan_flags.inc"
 #undef RTSAN_FLAG
+
+  bool ContainsSuppresionFile() { return suppressions[0] != '\0'; }
 };
 
 extern Flags flags_data;
diff --git a/compiler-rt/lib/rtsan/rtsan_stats.cpp b/compiler-rt/lib/rtsan/rtsan_stats.cpp
index dac7b23c3ef520..1562b73cf94cd8 100644
--- a/compiler-rt/lib/rtsan/rtsan_stats.cpp
+++ b/compiler-rt/lib/rtsan/rtsan_stats.cpp
@@ -11,6 +11,7 @@
 //===----------------------------------------------------------------------===//
 
 #include "rtsan/rtsan_stats.h"
+#include "rtsan/rtsan_flags.h"
 
 #include "sanitizer_common/sanitizer_atomic.h"
 #include "sanitizer_common/sanitizer_common.h"
@@ -20,6 +21,7 @@ using namespace __rtsan;
 
 static atomic_uint32_t rtsan_total_error_count{0};
 static atomic_uint32_t rtsan_unique_error_count{0};
+static atomic_uint32_t rtsan_suppressed_count{0};
 
 void __rtsan::IncrementTotalErrorCount() {
   atomic_fetch_add(&rtsan_total_error_count, 1, memory_order_relaxed);
@@ -37,9 +39,20 @@ static u32 GetUniqueErrorCount() {
   return atomic_load(&rtsan_unique_error_count, memory_order_relaxed);
 }
 
+void __rtsan::IncrementSuppressedCount() {
+  atomic_fetch_add(&rtsan_suppressed_count, 1, memory_order_relaxed);
+}
+
+static u32 GetSuppressedCount() {
+  return atomic_load(&rtsan_suppressed_count, memory_order_relaxed);
+}
+
 void __rtsan::PrintStatisticsSummary() {
   ScopedErrorReportLock l;
   Printf("RealtimeSanitizer exit stats:\n");
   Printf("    Total error count: %u\n", GetTotalErrorCount());
   Printf("    Unique error count: %u\n", GetUniqueErrorCount());
+
+  if (flags().ContainsSuppresionFile())
+    Printf("    Suppression count: %u\n", GetSuppressedCount());
 }
diff --git a/compiler-rt/lib/rtsan/rtsan_stats.h b/compiler-rt/lib/rtsan/rtsan_stats.h
index a72098792c89c9..a8a67ea2a44b6d 100644
--- a/compiler-rt/lib/rtsan/rtsan_stats.h
+++ b/compiler-rt/lib/rtsan/rtsan_stats.h
@@ -16,6 +16,7 @@ namespace __rtsan {
 
 void IncrementTotalErrorCount();
 void IncrementUniqueErrorCount();
+void IncrementSuppressedCount();
 
 void PrintStatisticsSummary();
 
diff --git a/compiler-rt/lib/rtsan/rtsan_suppressions.cpp b/compiler-rt/lib/rtsan/rtsan_suppressions.cpp
index a7c3d42ac68af9..2bcfbeed4195bc 100644
--- a/compiler-rt/lib/rtsan/rtsan_suppressions.cpp
+++ b/compiler-rt/lib/rtsan/rtsan_suppressions.cpp
@@ -56,7 +56,7 @@ void __rtsan::InitializeSuppressions() {
   CHECK_EQ(nullptr, suppression_ctx);
 
   // We will use suppression_ctx == nullptr as an early out
-  if (flags().suppressions[0] == '\0')
+  if (!flags().ContainsSuppresionFile())
     return;
 
   suppression_ctx = new (suppression_placeholder)
diff --git a/compiler-rt/test/rtsan/exit_stats.cpp b/compiler-rt/test/rtsan/exit_stats.cpp
index d4d19ace778ba5..92ca58f1edde86 100644
--- a/compiler-rt/test/rtsan/exit_stats.cpp
+++ b/compiler-rt/test/rtsan/exit_stats.cpp
@@ -1,6 +1,7 @@
 // RUN: %clangxx -fsanitize=realtime %s -o %t
 // RUN: %env_rtsan_opts="halt_on_error=false,print_stats_on_exit=true" %run %t 2>&1 | FileCheck %s
 // RUN: %env_rtsan_opts="halt_on_error=true,print_stats_on_exit=true" not %run %t 2>&1 | FileCheck %s --check-prefix=CHECK-HALT
+// RUN: %env_rtsan_opts="suppressions=%s.supp,print_stats_on_exit=true" not %run %t 2>&1 | FileCheck %s --check-prefix=CHECK-SUPPRESSIONS
 
 // UNSUPPORTED: ios
 
@@ -23,7 +24,17 @@ int main() {
 // CHECK: RealtimeSanitizer exit stats:
 // CHECK-NEXT: Total error count: 10
 // CHECK-NEXT: Unique error count: 1
+// CHECK-NOT: Suppression count
 
 // CHECK-HALT: RealtimeSanitizer exit stats:
 // CHECK-HALT-NEXT: Total error count: 1
 // CHECK-HALT-NEXT: Unique error count: 1
+// CHECK-HALT-NOT: Suppression count
+
+// We pass in intentionally_non_existant_function in the suppressions file
+// This is just to ensure we only get the "Suppression count" metric if this
+// file is passed at runtime, otherwise that statistic is omitted
+// CHECK-SUPPRESSIONS: RealtimeSanitizer exit stats:
+// CHECK-SUPPRESSIONS-NEXT: Total error count: 1
+// CHECK-SUPPRESSIONS-NEXT: Unique error count: 1
+// CHECK-SUPPRESSIONS-NEXT: Suppression count: 0
diff --git a/compiler-rt/test/rtsan/exit_stats.cpp.supp b/compiler-rt/test/rtsan/exit_stats.cpp.supp
new file mode 100644
index 00000000000000..b720bdb770808b
--- /dev/null
+++ b/compiler-rt/test/rtsan/exit_stats.cpp.supp
@@ -0,0 +1 @@
+function-name-matches:intentionally_non_existant_function
diff --git a/compiler-rt/test/rtsan/stack_suppressions.cpp b/compiler-rt/test/rtsan/stack_suppressions.cpp
index b9b2d0957636d9..be1cf4963c7f80 100644
--- a/compiler-rt/test/rtsan/stack_suppressions.cpp
+++ b/compiler-rt/test/rtsan/stack_suppressions.cpp
@@ -1,6 +1,6 @@
 // RUN: %clangxx -fsanitize=realtime %s -o %t
 // RUN: %env_rtsan_opts=halt_on_error=false %run %t 2>&1 | FileCheck %s --check-prefix=CHECK-NOSUPPRESSIONS
-// RUN: %env_rtsan_opts=suppressions='%s.supp' not %run %t 2>&1 | FileCheck %s
+// RUN: %env_rtsan_opts=suppressions='%s.supp':print_stats_on_exit=true not %run %t 2>&1 | FileCheck %s
 // UNSUPPORTED: ios
 
 // Intent: Ensure that suppressions work as intended
@@ -61,6 +61,9 @@ int main() {
 // CHECK-NOT: free
 // CHECK-NOT: BlockFunc
 
+// CHECK: RealtimeSanitizer exit stats:
+// CHECK: Suppression count: 7
+
 // CHECK-NOSUPPRESSIONS: malloc
 // CHECK-NOSUPPRESSIONS: vector
 // CHECK-NOSUPPRESSIONS: free