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

[Chris Apple via llvm-commits]

https://github.com/cjappl created https://github.com/llvm/llvm-project/pull/107014

As we solidify our external facing bits, I wanted to clean up the call stack. This is also necessary when we de-duplicate the "continue mode", which will come later down the road - we need to record the program counter as high up as feasible.

Functionally, this change affects only our printed stack traces. New version:
```
Real-time violation: intercepted call to real-time unsafe function `malloc` in real-time context! Stack trace:
    #0 0xaaaaab737be0 in malloc rtsan_interceptors.cpp:310:3
    #1 0xffffbe804b48 in operator new(unsigned long) 
   ...                                             
```

Previous call stack had internal bits:

```
Real-time violation: intercepted call to real-time unsafe function 
`malloc` in real-time context! Stack trace:
    #0 0x103184630 in __rtsan::printStackTrace() rtsan_stack.cpp:36
    #1 0x1031842f4 in __rtsan::Context::ExpectNotRealtime(char const*)
    #2 0x103184cfc in malloc rtsan_interceptors.cpp:225
```

>From f6d769e6ad8110a5e787ed0e78eb32aff9d3e707 Mon Sep 17 00:00:00 2001
From: Chris Apple <cja-private at pm.me>
Date: Sat, 31 Aug 2024 11:51:29 -0700
Subject: [PATCH] [compiler-rt][rtsan] Record pc and bp higher up in the stack

---
 compiler-rt/lib/rtsan/rtsan_context.cpp | 11 ++++++++---
 compiler-rt/lib/rtsan/rtsan_context.h   |  5 ++++-
 compiler-rt/lib/rtsan/rtsan_stack.cpp   |  3 +--
 compiler-rt/lib/rtsan/rtsan_stack.h     |  4 +++-
 compiler-rt/test/rtsan/basic.cpp        |  4 ++--
 5 files changed, 18 insertions(+), 9 deletions(-)

diff --git a/compiler-rt/lib/rtsan/rtsan_context.cpp b/compiler-rt/lib/rtsan/rtsan_context.cpp
index 81ee44670ff3e8..abeaa1e8483493 100644
--- a/compiler-rt/lib/rtsan/rtsan_context.cpp
+++ b/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() {
diff --git a/compiler-rt/lib/rtsan/rtsan_context.h b/compiler-rt/lib/rtsan/rtsan_context.h
index c8f0bf20e75a78..4196137e70b265 100644
--- a/compiler-rt/lib/rtsan/rtsan_context.h
+++ b/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
diff --git a/compiler-rt/lib/rtsan/rtsan_stack.cpp b/compiler-rt/lib/rtsan/rtsan_stack.cpp
index 43fd5fbf05509d..0598af2337ed18 100644
--- a/compiler-rt/lib/rtsan/rtsan_stack.cpp
+++ b/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();
diff --git a/compiler-rt/lib/rtsan/rtsan_stack.h b/compiler-rt/lib/rtsan/rtsan_stack.h
index cecdd43045db50..38f811fa8643df 100644
--- a/compiler-rt/lib/rtsan/rtsan_stack.h
+++ b/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
diff --git a/compiler-rt/test/rtsan/basic.cpp b/compiler-rt/test/rtsan/basic.cpp
index ec7382cb0ecaff..c7cbfcda31562e 100644
--- a/compiler-rt/test/rtsan/basic.cpp
+++ b/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*}}
 }