[compiler-rt] [HWASAN] Add bcmp interceptor (PR #69257)

[Kirill Stoimenov via llvm-commits]

https://github.com/kstoimenov created https://github.com/llvm/llvm-project/pull/69257

None

>From a19a2e3a6ebbeaa0769b3b0cbb6f2b8552cf1ad2 Mon Sep 17 00:00:00 2001
From: Kirill Stoimenov <kstoimenov at google.com>
Date: Mon, 16 Oct 2023 22:17:16 +0000
Subject: [PATCH] [HWASAN] Add bcmp interceptor

---
 .../lib/hwasan/hwasan_platform_interceptors.h |  4 +--
 compiler-rt/test/hwasan/TestCases/bcmp.cpp    | 27 +++++++++++++++++++
 2 files changed, 29 insertions(+), 2 deletions(-)
 create mode 100644 compiler-rt/test/hwasan/TestCases/bcmp.cpp

diff --git a/compiler-rt/lib/hwasan/hwasan_platform_interceptors.h b/compiler-rt/lib/hwasan/hwasan_platform_interceptors.h
index 390c9d80c38edd9..86d26b5ac12d4a7 100644
--- a/compiler-rt/lib/hwasan/hwasan_platform_interceptors.h
+++ b/compiler-rt/lib/hwasan/hwasan_platform_interceptors.h
@@ -68,8 +68,8 @@
 // #undef SANITIZER_INTERCEPT_MEMCMP
 // #define SANITIZER_INTERCEPT_MEMCMP 0
 
-#undef SANITIZER_INTERCEPT_BCMP
-#define SANITIZER_INTERCEPT_BCMP 0
+// #undef SANITIZER_INTERCEPT_BCMP
+// #define SANITIZER_INTERCEPT_BCMP 0
 
 #undef SANITIZER_INTERCEPT_STRNDUP
 #define SANITIZER_INTERCEPT_STRNDUP 0
diff --git a/compiler-rt/test/hwasan/TestCases/bcmp.cpp b/compiler-rt/test/hwasan/TestCases/bcmp.cpp
new file mode 100644
index 000000000000000..3dee4b8490efc06
--- /dev/null
+++ b/compiler-rt/test/hwasan/TestCases/bcmp.cpp
@@ -0,0 +1,27 @@
+// RUN: %clangxx_hwasan -O0 %s -o %t && not %run %t 2>&1 | FileCheck %s
+// RUN: %clangxx_hwasan -O1 %s -o %t && not %run %t 2>&1 | FileCheck %s
+// RUN: %clangxx_hwasan -O2 %s -o %t && not %run %t 2>&1 | FileCheck %s
+// RUN: %clangxx_hwasan -O3 %s -o %t && not %run %t 2>&1 | FileCheck %s
+
+#include <sanitizer/hwasan_interface.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+int main(int argc, char **argv) {
+  __hwasan_enable_allocator_tagging();
+  char a[] = {static_cast<char>(argc), 2, 3, 4};
+  int size = sizeof(a);
+  char *p = (char *)malloc(size);
+  memcpy(p, a, size);
+  free(p);
+  return bcmp(p, a, size);
+  // CHECK: HWAddressSanitizer: tag-mismatch on address
+  // CHECK: READ of size 4
+  // CHECK: #{{[[:digit:]]+}} 0x{{[[:xdigit:]]+}} in main {{.*}}bcmp.cpp:[[@LINE-3]]
+  // CHECK: Cause: use-after-free
+  // CHECK: freed by thread
+  // CHECK: #{{[[:digit:]]+}} 0x{{[[:xdigit:]]+}} in main {{.*}}bcmp.cpp:[[@LINE-7]]
+  // CHECK: previously allocated by thread
+  // CHECK: #{{[[:digit:]]+}} 0x{{[[:xdigit:]]+}} in main {{.*}}bcmp.cpp:[[@LINE-11]]
+}