[asan] Add strndup/__strndup interceptors.

Recommit of r302781 with Vitaly Buka's fix for non zero terminated strings.

Differential Revision: https://reviews.llvm.org/D31457


git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@304399 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 7 insertions, 29 deletions

diff --git a/lib/msan/msan_interceptors.cc b/lib/msan/msan_interceptors.cc
index ab08744a7..fbc2ea4fe 100644
--- a/lib/msan/msan_interceptors.cc
+++ b/lib/msan/msan_interceptors.cc
@@ -341,33 +341,6 @@ INTERCEPTOR(char *, __strdup, char *src) {
 #define MSAN_MAYBE_INTERCEPT___STRDUP
 #endif
 
-INTERCEPTOR(char *, strndup, char *src, SIZE_T n) {
-  ENSURE_MSAN_INITED();
-  GET_STORE_STACK_TRACE;
-  // On FreeBSD strndup() leverages strnlen().
-  InterceptorScope interceptor_scope;
-  SIZE_T copy_size = REAL(strnlen)(src, n);
-  char *res = REAL(strndup)(src, n);
-  CopyShadowAndOrigin(res, src, copy_size, &stack);
-  __msan_unpoison(res + copy_size, 1); // \0
-  return res;
-}
-
-#if !SANITIZER_FREEBSD
-INTERCEPTOR(char *, __strndup, char *src, SIZE_T n) {
-  ENSURE_MSAN_INITED();
-  GET_STORE_STACK_TRACE;
-  SIZE_T copy_size = REAL(strnlen)(src, n);
-  char *res = REAL(__strndup)(src, n);
-  CopyShadowAndOrigin(res, src, copy_size, &stack);
-  __msan_unpoison(res + copy_size, 1); // \0
-  return res;
-}
-#define MSAN_MAYBE_INTERCEPT___STRNDUP INTERCEPT_FUNCTION(__strndup)
-#else
-#define MSAN_MAYBE_INTERCEPT___STRNDUP
-#endif
-
 INTERCEPTOR(char *, gcvt, double number, SIZE_T ndigit, char *buf) {
   ENSURE_MSAN_INITED();
   char *res = REAL(gcvt)(number, ndigit, buf);
@@ -1373,6 +1346,13 @@ int OnExit() {
     return __msan_memcpy(to, from, size);                   \
   }
 
+#define COMMON_INTERCEPTOR_COPY_STRING(ctx, to, from, size)                    \
+  do {                                                                         \
+    GET_STORE_STACK_TRACE;                                                     \
+    CopyShadowAndOrigin(to, from, size, &stack);                               \
+    __msan_unpoison(to + size, 1);                                             \
+  } while (false)
+
 #include "sanitizer_common/sanitizer_platform_interceptors.h"
 #include "sanitizer_common/sanitizer_common_interceptors.inc"
 
@@ -1540,8 +1520,6 @@ void InitializeInterceptors() {
   INTERCEPT_FUNCTION(stpcpy);  // NOLINT
   INTERCEPT_FUNCTION(strdup);
   MSAN_MAYBE_INTERCEPT___STRDUP;
-  INTERCEPT_FUNCTION(strndup);
-  MSAN_MAYBE_INTERCEPT___STRNDUP;
   INTERCEPT_FUNCTION(strncpy);  // NOLINT
   INTERCEPT_FUNCTION(gcvt);
   INTERCEPT_FUNCTION(strcat);  // NOLINT