[compiler-rt] compiler-rt: ubsan: Fix suppressions for inlined functions (PR #206735)

[via llvm-commits]

https://github.com/maflcko updated https://github.com/llvm/llvm-project/pull/206735

>From 36f97626f82604a9de89018c43c69270cbacd8f2 Mon Sep 17 00:00:00 2001
From: MarcoFalke <*~=`'#}+{/-|&$^_ at 721217.xyz>
Date: Mon, 13 Jul 2026 14:00:54 +0200
Subject: [PATCH] compiler-rt: ubsan: Fix suppressions for inlined functions

Align suppression PC handling with getCallerLocation(), so function
suppressions identify the inlined function that caused a report.

Intentionally match only the innermost inline frame.

Extend suppressions-nested-calls.c coverage to -O1.
---
 compiler-rt/lib/ubsan/ubsan_diag.cpp                       | 6 ++++++
 .../ubsan/TestCases/Integer/suppressions-nested-calls.c    | 7 +++++++
 2 files changed, 13 insertions(+)

diff --git a/compiler-rt/lib/ubsan/ubsan_diag.cpp b/compiler-rt/lib/ubsan/ubsan_diag.cpp
index 6efd082a89934..d06af776b54e1 100644
--- a/compiler-rt/lib/ubsan/ubsan_diag.cpp
+++ b/compiler-rt/lib/ubsan/ubsan_diag.cpp
@@ -438,6 +438,9 @@ bool __ubsan::IsVptrCheckSuppressed(const char *TypeName) {
 bool __ubsan::IsPCSuppressed(ErrorType ET, uptr PC, const char *Filename) {
   InitAsStandaloneIfNecessary();
   CHECK(suppression_ctx);
+  // PC is the return address from the UBSan handler call. Symbolize the
+  // instruction that caused the call.
+  PC = StackTrace::GetPreviousInstructionPc(PC);
   const char *SuppType = ConvertTypeToFlagName(ET);
   // Fast path: don't symbolize PC if there is no suppressions for given UB
   // type.
@@ -453,6 +456,9 @@ bool __ubsan::IsPCSuppressed(ErrorType ET, uptr PC, const char *Filename) {
       return true;
   }
   // Suppress by function or source file name from debug info.
+  // The first frame is the innermost logical inline frame, if inline debug
+  // information is available. Do not search the rest of the chain: a
+  // suppression for an inline wrapper must not suppress an inlined callee.
   SymbolizedStackHolder Stack(Symbolizer::GetOrInit()->SymbolizePC(PC));
   const AddressInfo &AI = Stack.get()->info;
   return suppression_ctx->Match(AI.function, SuppType, &s) ||
diff --git a/compiler-rt/test/ubsan/TestCases/Integer/suppressions-nested-calls.c b/compiler-rt/test/ubsan/TestCases/Integer/suppressions-nested-calls.c
index 487d35eaa83f4..65b363bb5f9ae 100644
--- a/compiler-rt/test/ubsan/TestCases/Integer/suppressions-nested-calls.c
+++ b/compiler-rt/test/ubsan/TestCases/Integer/suppressions-nested-calls.c
@@ -4,6 +4,7 @@
 // # Test for UBSan suppressions with nested function calls
 //
 // RUN: %clang -fsanitize=integer -O0 -g %s -o %t.o0
+// RUN: %clang -fsanitize=integer -O1 -g %s -o %t.o1
 //
 // # Only the directly suppressed my_make_signed hit should disappear.
 // RUN: echo "implicit-integer-sign-change:my_make_signed" > %t.make_signed.name.supp
@@ -11,6 +12,8 @@
 //
 // RUN: %env_ubsan_opts=suppressions='"%t.make_signed.name.supp"' %run %t.o0 2>&1 | FileCheck %s --check-prefix=CHECK-MAKE-SIGNED
 // RUN: %env_ubsan_opts=suppressions='"%t.make_signed.file.supp"' %run %t.o0 2>&1 | FileCheck %s --check-prefix=CHECK-MAKE-SIGNED
+// RUN: %env_ubsan_opts=suppressions='"%t.make_signed.name.supp"' %run %t.o1 2>&1 | FileCheck %s --check-prefix=CHECK-MAKE-SIGNED
+// RUN: %env_ubsan_opts=suppressions='"%t.make_signed.file.supp"' %run %t.o1 2>&1 | FileCheck %s --check-prefix=CHECK-MAKE-SIGNED
 //
 // # Only the suppressed wrapper-originated hit should disappear.
 // RUN: echo "implicit-integer-sign-change:my_wrapper_2" > %t.my_wrapper_2.name.supp
@@ -18,6 +21,8 @@
 //
 // RUN: %env_ubsan_opts=suppressions='"%t.my_wrapper_2.name.supp"' %run %t.o0 2>&1 | FileCheck %s --check-prefix=CHECK-WRAPPERS
 // RUN: %env_ubsan_opts=suppressions='"%t.wrappers.file.supp"'     %run %t.o0 2>&1 | FileCheck %s --check-prefix=CHECK-WRAPPERS
+// RUN: %env_ubsan_opts=suppressions='"%t.my_wrapper_2.name.supp"' %run %t.o1 2>&1 | FileCheck %s --check-prefix=CHECK-WRAPPERS
+// RUN: %env_ubsan_opts=suppressions='"%t.wrappers.file.supp"'     %run %t.o1 2>&1 | FileCheck %s --check-prefix=CHECK-WRAPPERS
 //
 // # Suppress both.
 // RUN: cat %t.make_signed.name.supp %t.my_wrapper_2.name.supp > %t.both.name.supp
@@ -25,6 +30,8 @@
 //
 // RUN: %env_ubsan_opts=suppressions='"%t.both.name.supp"' %run %t.o0 2>&1 | FileCheck %s --allow-empty --check-prefix=CHECK-BOTH
 // RUN: %env_ubsan_opts=suppressions='"%t.both.file.supp"' %run %t.o0 2>&1 | FileCheck %s --allow-empty --check-prefix=CHECK-BOTH
+// RUN: %env_ubsan_opts=suppressions='"%t.both.name.supp"' %run %t.o1 2>&1 | FileCheck %s --allow-empty --check-prefix=CHECK-BOTH
+// RUN: %env_ubsan_opts=suppressions='"%t.both.file.supp"' %run %t.o1 2>&1 | FileCheck %s --allow-empty --check-prefix=CHECK-BOTH
 
 #include "Inputs/make_signed.h"
 #include "Inputs/wrappers.h"