Revert r302781 and subsequent attempts to disable part of it.

The Msan unit tests are still broken and by this point, I think we
should start over.

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@303339 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 31 insertions, 11 deletions

diff --git a/lib/msan/msan_interceptors.cc b/lib/msan/msan_interceptors.cc
index 0f5069344..15543bd91 100644
--- a/lib/msan/msan_interceptors.cc
+++ b/lib/msan/msan_interceptors.cc
@@ -341,6 +341,33 @@ 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);
@@ -1344,13 +1371,6 @@ 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"
 
@@ -1518,6 +1538,8 @@ 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
diff --git a/lib/msan/tests/msan_test.cc b/lib/msan/tests/msan_test.cc
index 58f695e69..c7c91324a 100644
--- a/lib/msan/tests/msan_test.cc
+++ b/lib/msan/tests/msan_test.cc
@@ -1581,8 +1581,7 @@ TEST(MemorySanitizer, strdup) {
 TEST(MemorySanitizer, strndup) {
   char buf[4] = "abc";
   __msan_poison(buf + 2, sizeof(*buf));
-  char *x;
-  EXPECT_UMR(x = strndup(buf, 3));
+  char *x = strndup(buf, 3);
   EXPECT_NOT_POISONED(x[0]);
   EXPECT_NOT_POISONED(x[1]);
   EXPECT_POISONED(x[2]);
@@ -1594,8 +1593,7 @@ TEST(MemorySanitizer, strndup_short) {
   char buf[4] = "abc";
   __msan_poison(buf + 1, sizeof(*buf));
   __msan_poison(buf + 2, sizeof(*buf));
-  char *x;
-  EXPECT_UMR(x = strndup(buf, 2));
+  char *x = strndup(buf, 2);
   EXPECT_NOT_POISONED(x[0]);
   EXPECT_POISONED(x[1]);
   EXPECT_NOT_POISONED(x[2]);