[Msan] Intercept stat() and fstatat() on FreeBSD

[eugenis]

LGTM with a typo

lib/msan/msan_interceptors.cc

755

MSAN_INTERCEPT_STAT

lib/msan/msan_interceptors.cc

if (!res)
     __msan_unpoison(buf, __sanitizer::struct_stat64_sz);
   return res;
 }
 #define MSAN_MAYBE_INTERCEPT___FXSTAT64 INTERCEPT_FUNCTION(__fxstat64)
 #else
 #define MSAN_MAYBE_INTERCEPT___FXSTAT64
 #endif
 
-#if !SANITIZER_FREEBSD
+#if SANITIZER_FREEBSD
+INTERCEPTOR(int, fstatat, int fd, char *pathname, void *buf, int flags) {
+  ENSURE_MSAN_INITED();
+  int res = REAL(fstatat)(fd, pathname, buf, flags);
+  if (!res) __msan_unpoison(buf, __sanitizer::struct_stat_sz);
+  return res;
+}
+# define MSAN_INTERCEPT_FSTATAT INTERCEPT_FUNCTION(fstatat)
+#else
 INTERCEPTOR(int, __fxstatat, int magic, int fd, char *pathname, void *buf,
             int flags) {
   ENSURE_MSAN_INITED();
   int res = REAL(__fxstatat)(magic, fd, pathname, buf, flags);
   if (!res) __msan_unpoison(buf, __sanitizer::struct_stat_sz);
   return res;
 }
-#define MSAN_MAYBE_INTERCEPT___FXSTATAT INTERCEPT_FUNCTION(__fxstatat)
-#else
-#define MSAN_MAYBE_INTERCEPT___FXSTATAT
+# define MSAN_INTERCEPT_FSTATAT INTERCEPT_FUNCTION(__fxstatat)
 #endif
 
 #if !SANITIZER_FREEBSD
 INTERCEPTOR(int, __fxstatat64, int magic, int fd, char *pathname, void *buf,
             int flags) {
   ENSURE_MSAN_INITED();
   int res = REAL(__fxstatat64)(magic, fd, pathname, buf, flags);
   if (!res) __msan_unpoison(buf, __sanitizer::struct_stat64_sz);
   return res;
 }
 #define MSAN_MAYBE_INTERCEPT___FXSTATAT64 INTERCEPT_FUNCTION(__fxstatat64)
 #else
 #define MSAN_MAYBE_INTERCEPT___FXSTATAT64
 #endif
 
-#if !SANITIZER_FREEBSD
+#if SANITIZER_FREEBSD
+INTERCEPTOR(int, stat, char *path, void *buf) {
+  ENSURE_MSAN_INITED();
+  int res = REAL(stat)(path, buf);
+  if (!res)
+    __msan_unpoison(buf, __sanitizer::struct_stat_sz);
+  return res;
+}
+# define MSAN_INTERCEPT_STAT INTERCEPT_FUNCTION(stat)
+#else
 INTERCEPTOR(int, __xstat, int magic, char *path, void *buf) {
   ENSURE_MSAN_INITED();
   int res = REAL(__xstat)(magic, path, buf);
   if (!res)
     __msan_unpoison(buf, __sanitizer::struct_stat_sz);
   return res;
 }
-#define MSAN_MAYBE_INTERCEPT___XSTAT INTERCEPT_FUNCTION(__xstat)
-#else
-#define MSAN_MAYBE_INTERCEPT___XSTAT
+# define MSAN_INTERCEPT_XSTAT INTERCEPT_FUNCTION(__xstat)
 #endif
 
 #if !SANITIZER_FREEBSD
 INTERCEPTOR(int, __xstat64, int magic, char *path, void *buf) {
   ENSURE_MSAN_INITED();
   int res = REAL(__xstat64)(magic, path, buf);
   if (!res)
     __msan_unpoison(buf, __sanitizer::struct_stat64_sz);
void InitializeInterceptors() {
   INTERCEPT_FUNCTION(wcscpy);
   INTERCEPT_FUNCTION(wcscmp);
   INTERCEPT_FUNCTION(getenv);
   INTERCEPT_FUNCTION(setenv);
   INTERCEPT_FUNCTION(putenv);
   INTERCEPT_FUNCTION(gettimeofday);
   INTERCEPT_FUNCTION(fcvt);
   MSAN_MAYBE_INTERCEPT___FXSTAT;
-  MSAN_MAYBE_INTERCEPT___FXSTATAT;
-  MSAN_MAYBE_INTERCEPT___XSTAT;
+  MSAN_INTERCEPT_FSTATAT;
+  MSAN_INTERCEPT_STAT;
   MSAN_MAYBE_INTERCEPT___LXSTAT;
   MSAN_MAYBE_INTERCEPT___FXSTAT64;
   MSAN_MAYBE_INTERCEPT___FXSTATAT64;
   MSAN_MAYBE_INTERCEPT___XSTAT64;
   MSAN_MAYBE_INTERCEPT___LXSTAT64;
   INTERCEPT_FUNCTION(pipe);
   INTERCEPT_FUNCTION(pipe2);
   INTERCEPT_FUNCTION(socketpair);

lib/msan/tests/msan_test.cc

 
 #ifdef __AVX2__
 # include <immintrin.h>
 #endif
 
 // On FreeBSD procfs is not enabled by default.
 #if defined(__FreeBSD__)
 # define FILE_TO_READ "/bin/cat"
+# define DIR_TO_READ "/bin"
+# define SUBFILE_TO_READ "cat"
 #else
 # define FILE_TO_READ "/proc/self/stat"
+# define DIR_TO_READ "/proc/self"
+# define SUBFILE_TO_READ "stat"
 #endif
 
 static const size_t kPageSize = 4096;
 
 typedef unsigned char      U1;
 typedef unsigned short     U2;  // NOLINT
 typedef unsigned int       U4;
 typedef unsigned long long U8;  // NOLINT
TEST(MemorySanitizer, stat) {
   ASSERT_EQ(0, res);
   EXPECT_NOT_POISONED(st->st_dev);
   EXPECT_NOT_POISONED(st->st_mode);
   EXPECT_NOT_POISONED(st->st_size);
 }
 
 TEST(MemorySanitizer, fstatat) {
   struct stat* st = new struct stat;
-  int dirfd = open("/proc/self", O_RDONLY);
+  int dirfd = open(DIR_TO_READ, O_RDONLY);
   ASSERT_GT(dirfd, 0);
-  int res = fstatat(dirfd, "stat", st, 0);
+  int res = fstatat(dirfd, SUBFILE_TO_READ, st, 0);
   ASSERT_EQ(0, res);
   EXPECT_NOT_POISONED(st->st_dev);
   EXPECT_NOT_POISONED(st->st_mode);
   EXPECT_NOT_POISONED(st->st_size);
   close(dirfd);
 }
 
 TEST(MemorySanitizer, statfs) {