[compiler-rt][rtsan] Record pc and bp higher up in the stack (#107014)

Functionally, this change affects only our printed stack traces. New
version does not expose any internal rtsan interworking

Author: cjappl

compiler-rt/lib/rtsan/rtsan_context.cpp

@@ -20,6 +20,8 @@
 #include <stdio.h>
 #include <stdlib.h>
 
+using namespace __sanitizer;
+
 static pthread_key_t context_key;
 static pthread_once_t key_once = PTHREAD_ONCE_INIT;
 
@@ -75,7 +77,9 @@ void __rtsan::ExpectNotRealtime(Context &context,
                                 const char *intercepted_function_name) {
   if (context.InRealtimeContext() && !context.IsBypassed()) {
     context.BypassPush();
-    PrintDiagnostics(intercepted_function_name);
+
+    GET_CALLER_PC_BP;
+    PrintDiagnostics(intercepted_function_name, pc, bp);
     InvokeViolationDetectedAction();
     context.BypassPop();
   }
@@ -85,12 +89,13 @@ bool __rtsan::Context::InRealtimeContext() const { return realtime_depth_ > 0; }
 
 bool __rtsan::Context::IsBypassed() const { return bypass_depth_ > 0; }
 
-void __rtsan::PrintDiagnostics(const char *intercepted_function_name) {
+void __rtsan::PrintDiagnostics(const char *intercepted_function_name, uptr pc,
+                               uptr bp) {
   fprintf(stderr,
           "Real-time violation: intercepted call to real-time unsafe function "
           "`%s` in real-time context! Stack trace:\n",
           intercepted_function_name);
-  __rtsan::PrintStackTrace();
+  __rtsan::PrintStackTrace(pc, bp);
 }
 
 __rtsan::Context &__rtsan::GetContextForThisThread() {

compiler-rt/lib/rtsan/rtsan_context.h

@@ -10,6 +10,8 @@
 
 #pragma once
 
+#include <sanitizer_common/sanitizer_internal_defs.h>
+
 namespace __rtsan {
 
 class Context {
@@ -38,6 +40,7 @@ class Context {
 Context &GetContextForThisThread();
 
 void ExpectNotRealtime(Context &context, const char *intercepted_function_name);
-void PrintDiagnostics(const char *intercepted_function_name);
+void PrintDiagnostics(const char *intercepted_function_name,
+                      __sanitizer::uptr pc, __sanitizer::uptr bp);
 
 } // namespace __rtsan

compiler-rt/lib/rtsan/rtsan_stack.cpp

@@ -38,11 +38,10 @@ static void SetGlobalStackTraceFormat() {
   OverrideCommonFlags(cf);
 }
 
-void __rtsan::PrintStackTrace() {
+void __rtsan::PrintStackTrace(uptr pc, uptr bp) {
 
   BufferedStackTrace stack{};
 
-  GET_CURRENT_PC_BP;
   stack.Unwind(pc, bp, nullptr, common_flags()->fast_unwind_on_fatal);
 
   SetGlobalStackTraceFormat();

compiler-rt/lib/rtsan/rtsan_stack.h

@@ -10,6 +10,8 @@
 
 #pragma once
 
+#include <sanitizer_common/sanitizer_internal_defs.h>
+
 namespace __rtsan {
-void PrintStackTrace();
+void PrintStackTrace(__sanitizer::uptr pc, __sanitizer::uptr bp);
 } // namespace __rtsan

compiler-rt/test/rtsan/basic.cpp

@@ -16,6 +16,6 @@ void violation() [[clang::nonblocking]] {
 int main() {
   violation();
   return 0;
-  // CHECK: {{.*Real-time violation.*}}
-  // CHECK: {{.*malloc*}}
+  // CHECK: Real-time violation: intercepted call to real-time unsafe function `malloc` in real-time context! Stack trace:
+  // CHECK-NEXT: {{.*malloc*}}
 }