From 8cee2e8539ae8dea441470401378979965a652b2 Mon Sep 17 00:00:00 2001
From: Evgeniy Stepanov <eugeni.stepanov@gmail.com>
Date: Mon, 4 Mar 2019 22:58:11 +0000
Subject: [PATCH] [sanitizer] Intercept bzero.

Summary:
Intercept bzero and enable existing __bzero interceptor in Linux.
bzero is deprecated but still used occasionally.

Reviewers: vitalybuka

Subscribers: srhines, kubamracek, #sanitizers, llvm-commits

Tags: #sanitizers, #llvm

Differential Revision: https://reviews.llvm.org/D58850

llvm-svn: 355347
---
 .../sanitizer_common_interceptors.inc            | 12 +++++++++++-
 .../sanitizer_platform_interceptors.h            |  3 ++-
 compiler-rt/test/asan/TestCases/Linux/bzero.cc   | 15 +++++++++++++++
 compiler-rt/test/msan/Linux/bzero.cc             | 16 ++++++++++++++++
 4 files changed, 44 insertions(+), 2 deletions(-)
 create mode 100644 compiler-rt/test/asan/TestCases/Linux/bzero.cc
 create mode 100644 compiler-rt/test/msan/Linux/bzero.cc

diff --git a/compiler-rt/lib/sanitizer_common/sanitizer_common_interceptors.inc b/compiler-rt/lib/sanitizer_common/sanitizer_common_interceptors.inc
index abe487e830c3..4ea274f7840c 100644
--- a/compiler-rt/lib/sanitizer_common/sanitizer_common_interceptors.inc
+++ b/compiler-rt/lib/sanitizer_common/sanitizer_common_interceptors.inc
@@ -5529,12 +5529,21 @@ INTERCEPTOR(void *, __bzero, void *block, uptr size) {
   void *ctx;
   COMMON_INTERCEPTOR_MEMSET_IMPL(ctx, block, 0, size);
 }
-
 #define INIT___BZERO COMMON_INTERCEPT_FUNCTION(__bzero);
 #else
 #define INIT___BZERO
 #endif  // SANITIZER_INTERCEPT___BZERO
 
+#if SANITIZER_INTERCEPT_BZERO
+INTERCEPTOR(void *, bzero, void *block, uptr size) {
+  void *ctx;
+  COMMON_INTERCEPTOR_MEMSET_IMPL(ctx, block, 0, size);
+}
+#define INIT_BZERO COMMON_INTERCEPT_FUNCTION(bzero);
+#else
+#define INIT_BZERO
+#endif  // SANITIZER_INTERCEPT_BZERO
+
 #if SANITIZER_INTERCEPT_FTIME
 INTERCEPTOR(int, ftime, __sanitizer_timeb *tp) {
   void *ctx;
@@ -9693,6 +9702,7 @@ static void InitializeCommonInterceptors() {
   INIT_CAPGET;
   INIT_AEABI_MEM;
   INIT___BZERO;
+  INIT_BZERO;
   INIT_FTIME;
   INIT_XDR;
   INIT_TSEARCH;
diff --git a/compiler-rt/lib/sanitizer_common/sanitizer_platform_interceptors.h b/compiler-rt/lib/sanitizer_common/sanitizer_platform_interceptors.h
index 906740c8bfc8..a4116f8a0aa7 100644
--- a/compiler-rt/lib/sanitizer_common/sanitizer_platform_interceptors.h
+++ b/compiler-rt/lib/sanitizer_common/sanitizer_platform_interceptors.h
@@ -411,7 +411,8 @@
 #else
 #define SANITIZER_INTERCEPT_AEABI_MEM 0
 #endif
-#define SANITIZER_INTERCEPT___BZERO SI_MAC
+#define SANITIZER_INTERCEPT___BZERO SI_MAC || SI_LINUX_NOT_ANDROID
+#define SANITIZER_INTERCEPT_BZERO SI_LINUX_NOT_ANDROID
 #define SANITIZER_INTERCEPT_FTIME \
   (!SI_FREEBSD && !SI_NETBSD && !SI_OPENBSD && SI_POSIX)
 #define SANITIZER_INTERCEPT_XDR SI_LINUX_NOT_ANDROID || SI_SOLARIS
diff --git a/compiler-rt/test/asan/TestCases/Linux/bzero.cc b/compiler-rt/test/asan/TestCases/Linux/bzero.cc
new file mode 100644
index 000000000000..430edb744692
--- /dev/null
+++ b/compiler-rt/test/asan/TestCases/Linux/bzero.cc
@@ -0,0 +1,15 @@
+// RUN: %clangxx_asan -O0 %s -o %t && not %run %t 2>&1 | FileCheck %s
+
+// REQUIRES: !android
+
+#include <assert.h>
+#include <strings.h>
+
+int main(int argc, char *argv[]) {
+  char buf[100];
+  // *& to suppress bzero-to-memset optimization.
+  (*&bzero)(buf, sizeof(buf) + 1);
+  // CHECK:      AddressSanitizer: stack-buffer-overflow
+  // CHECK-NEXT: WRITE of size 101 at
+  return 0;
+}
diff --git a/compiler-rt/test/msan/Linux/bzero.cc b/compiler-rt/test/msan/Linux/bzero.cc
new file mode 100644
index 000000000000..cb319a6cfa1e
--- /dev/null
+++ b/compiler-rt/test/msan/Linux/bzero.cc
@@ -0,0 +1,16 @@
+// RUN: %clangxx_msan -O0 %s -o %t && %run %t
+
+// REQUIRES: !android
+
+#include <assert.h>
+#include <strings.h>
+#include <sanitizer/msan_interface.h>
+
+int main(int argc, char *argv[]) {
+  char buf[100];
+  assert(0 == __msan_test_shadow(buf, sizeof(buf)));
+  // *& to suppress bzero-to-memset optimization.
+  (*&bzero)(buf, 50);
+  assert(50 == __msan_test_shadow(buf, sizeof(buf)));
+  return 0;
+}