[compiler-rt] msan: Support free_sized and free_aligned_sized from C23 (PR #144529)

[Justin King via llvm-commits]

https://github.com/jcking updated https://github.com/llvm/llvm-project/pull/144529

>From 961ac5813ea019e6e9b7b24608a06bf3192c6851 Mon Sep 17 00:00:00 2001
From: Justin King <jcking at google.com>
Date: Wed, 18 Jun 2025 17:44:32 -0700
Subject: [PATCH] msan: Support free_sized and free_aligned_sized from C23

Signed-off-by: Justin King <jcking at google.com>
---
 compiler-rt/lib/msan/msan_interceptors.cpp    | 32 +++++++++++++++++++
 .../TestCases/Linux/free_aligned_sized.c      |  2 +-
 .../TestCases/Linux/free_sized.c              |  2 +-
 3 files changed, 34 insertions(+), 2 deletions(-)

diff --git a/compiler-rt/lib/msan/msan_interceptors.cpp b/compiler-rt/lib/msan/msan_interceptors.cpp
index f94d3cb79aa00..bc28434d1d494 100644
--- a/compiler-rt/lib/msan/msan_interceptors.cpp
+++ b/compiler-rt/lib/msan/msan_interceptors.cpp
@@ -34,6 +34,7 @@
 #include "sanitizer_common/sanitizer_glibc_version.h"
 #include "sanitizer_common/sanitizer_libc.h"
 #include "sanitizer_common/sanitizer_linux.h"
+#include "sanitizer_common/sanitizer_platform_interceptors.h"
 #include "sanitizer_common/sanitizer_platform_limits_netbsd.h"
 #include "sanitizer_common/sanitizer_platform_limits_posix.h"
 #include "sanitizer_common/sanitizer_stackdepot.h"
@@ -215,6 +216,35 @@ INTERCEPTOR(void, free, void *ptr) {
   MsanDeallocate(&stack, ptr);
 }
 
+#if SANITIZER_INTERCEPT_FREE_SIZED
+INTERCEPTOR(void, free_sized, void *ptr, uptr size) {
+  if (UNLIKELY(!ptr))
+    return;
+  if (DlsymAlloc::PointerIsMine(ptr))
+    return DlsymAlloc::Free(ptr);
+  GET_MALLOC_STACK_TRACE;
+  MsanDeallocate(&stack, ptr);
+}
+#  define MSAN_MAYBE_INTERCEPT_FREE_SIZED INTERCEPT_FUNCTION(free_sized)
+#else
+#  define MSAN_MAYBE_INTERCEPT_FREE_SIZED
+#endif
+
+#if SANITIZER_INTERCEPT_FREE_ALIGNED_SIZED
+INTERCEPTOR(void, free_aligned_sized, void *ptr, uptr alignment, uptr size) {
+  if (UNLIKELY(!ptr))
+    return;
+  if (DlsymAlloc::PointerIsMine(ptr))
+    return DlsymAlloc::Free(ptr);
+  GET_MALLOC_STACK_TRACE;
+  MsanDeallocate(&stack, ptr);
+}
+#  define MSAN_MAYBE_INTERCEPT_FREE_ALIGNED_SIZED \
+    INTERCEPT_FUNCTION(free_aligned_sized)
+#else
+#  define MSAN_MAYBE_INTERCEPT_FREE_ALIGNED_SIZED
+#endif
+
 #if !SANITIZER_FREEBSD && !SANITIZER_NETBSD
 INTERCEPTOR(void, cfree, void *ptr) {
   if (UNLIKELY(!ptr))
@@ -1775,6 +1805,8 @@ void InitializeInterceptors() {
   INTERCEPT_FUNCTION(realloc);
   INTERCEPT_FUNCTION(reallocarray);
   INTERCEPT_FUNCTION(free);
+  MSAN_MAYBE_INTERCEPT_FREE_SIZED;
+  MSAN_MAYBE_INTERCEPT_FREE_ALIGNED_SIZED;
   MSAN_MAYBE_INTERCEPT_CFREE;
   MSAN_MAYBE_INTERCEPT_MALLOC_USABLE_SIZE;
   MSAN_MAYBE_INTERCEPT_MALLINFO;
diff --git a/compiler-rt/test/sanitizer_common/TestCases/Linux/free_aligned_sized.c b/compiler-rt/test/sanitizer_common/TestCases/Linux/free_aligned_sized.c
index e9cb6f20c5ead..7710c62368191 100644
--- a/compiler-rt/test/sanitizer_common/TestCases/Linux/free_aligned_sized.c
+++ b/compiler-rt/test/sanitizer_common/TestCases/Linux/free_aligned_sized.c
@@ -1,5 +1,5 @@
 // RUN: %clang -std=c23 -O0 %s -o %t && %run %t
-// UNSUPPORTED: asan, hwasan, rtsan, tsan, msan, ubsan
+// UNSUPPORTED: asan, hwasan, rtsan, tsan, ubsan
 
 #include <stddef.h>
 #include <stdlib.h>
diff --git a/compiler-rt/test/sanitizer_common/TestCases/Linux/free_sized.c b/compiler-rt/test/sanitizer_common/TestCases/Linux/free_sized.c
index 8cdf3216e528a..9eac562fecb03 100644
--- a/compiler-rt/test/sanitizer_common/TestCases/Linux/free_sized.c
+++ b/compiler-rt/test/sanitizer_common/TestCases/Linux/free_sized.c
@@ -1,5 +1,5 @@
 // RUN: %clang -std=c23 -O0 %s -o %t && %run %t
-// UNSUPPORTED: asan, hwasan, rtsan, tsan, msan, ubsan
+// UNSUPPORTED: asan, hwasan, rtsan, tsan, ubsan
 
 #include <stddef.h>
 #include <stdlib.h>