[sanitizer] Intercept bzero.

[eugenis]

Summary

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

[eugenis]

rebase

lib/sanitizer_common/sanitizer_common_interceptors.inc

 #define INIT_AEABI_MEM
 #endif  // SANITIZER_INTERCEPT_AEABI_MEM
 
 #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_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;
   COMMON_INTERCEPTOR_ENTER(ctx, ftime, tp);
   // FIXME: under ASan the call below may write to freed memory and corrupt
   // its metadata. See
   // https://github.com/google/sanitizers/issues/321.
   int res = REAL(ftime)(tp);
static void InitializeCommonInterceptors() {
   INIT_LISTXATTR;
   INIT_GETXATTR;
   INIT_GETRESID;
   INIT_GETIFADDRS;
   INIT_IF_INDEXTONAME;
   INIT_CAPGET;
   INIT_AEABI_MEM;
   INIT___BZERO;
+  INIT_BZERO;
   INIT_FTIME;
   INIT_XDR;
   INIT_TSEARCH;
   INIT_LIBIO_INTERNALS;
   INIT_FOPEN;
   INIT_FOPEN64;
   INIT_OPEN_MEMSTREAM;
   INIT_OBSTACK;

lib/sanitizer_common/sanitizer_platform_interceptors.h

#define SANITIZER_INTERCEPT_IF_INDEXTONAME                                    \
   (SI_FREEBSD || SI_NETBSD || SI_OPENBSD || SI_LINUX_NOT_ANDROID || SI_MAC || \
   SI_SOLARIS)
 #define SANITIZER_INTERCEPT_CAPGET SI_LINUX_NOT_ANDROID
 #if SI_LINUX && defined(__arm__)
 #define SANITIZER_INTERCEPT_AEABI_MEM 1
 #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
 #define SANITIZER_INTERCEPT_TSEARCH \
   (SI_LINUX_NOT_ANDROID || SI_MAC || SI_NETBSD || SI_OPENBSD || SI_SOLARIS)
 #define SANITIZER_INTERCEPT_LIBIO_INTERNALS SI_LINUX_NOT_ANDROID
 #define SANITIZER_INTERCEPT_FOPEN SI_POSIX
 #define SANITIZER_INTERCEPT_FOPEN64 SI_LINUX_NOT_ANDROID || SI_SOLARIS32

test/asan/TestCases/Linux/bzero.cc

+// 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;
+}

test/msan/Linux/bzero.cc

+// 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;
+}