[compiler-rt][rtsan] Reland posix part of #121616 setbuf, setvbuf.

compiler-rt/lib/rtsan/rtsan_interceptors_posix.cpp

@@ -325,6 +325,23 @@ INTERCEPTOR(FILE *, fmemopen, void *buf, size_t size, const char *mode) {
 #define RTSAN_MAYBE_INTERCEPT_FMEMOPEN
 #endif
 
+#if SANITIZER_INTERCEPT_SETVBUF
+INTERCEPTOR(void, setbuf, FILE *stream, char *buf) {
+  __rtsan_notify_intercepted_call("setbuf");
+  return REAL(setbuf)(stream, buf);
+}
+
+INTERCEPTOR(int, setvbuf, FILE *stream, char *buf, int mode, size_t size) {
+  __rtsan_notify_intercepted_call("setvbuf");
+  return REAL(setvbuf)(stream, buf, mode, size);
+}
+#define RTSAN_MAYBE_INTERCEPT_SETBUF INTERCEPT_FUNCTION(setbuf)
+#define RTSAN_MAYBE_INTERCEPT_SETVBUF INTERCEPT_FUNCTION(setvbuf)
+#else
+#define RTSAN_MAYBE_INTERCEPT_SETBUF
+#define RTSAN_MAYBE_INTERCEPT_SETVBUF
+#endif
+
 INTERCEPTOR(int, puts, const char *s) {
   __rtsan_notify_intercepted_call("puts");
   return REAL(puts)(s);
@@ -986,6 +1003,8 @@ void __rtsan::InitializeInterceptors() {
   RTSAN_MAYBE_INTERCEPT_FOPENCOOKIE;
   RTSAN_MAYBE_INTERCEPT_OPEN_MEMSTREAM;
   RTSAN_MAYBE_INTERCEPT_FMEMOPEN;
+  RTSAN_MAYBE_INTERCEPT_SETBUF;
+  RTSAN_MAYBE_INTERCEPT_SETVBUF;
   INTERCEPT_FUNCTION(lseek);
   RTSAN_MAYBE_INTERCEPT_LSEEK64;
   INTERCEPT_FUNCTION(dup);

compiler-rt/lib/rtsan/tests/rtsan_test_interceptors_posix.cpp

@@ -403,6 +403,34 @@ TEST_F(RtsanFileTest, FmemOpenDiesWhenRealtime) {
 }
 #endif
 
+#if SANITIZER_INTERCEPT_SETVBUF
+TEST_F(RtsanFileTest, SetbufDieWhenRealtime) {
+  char buffer[BUFSIZ];
+  FILE *f = fopen(GetTemporaryFilePath(), "w");
+  EXPECT_THAT(f, Ne(nullptr));
+
+  auto Func = [&f, &buffer]() { setbuf(f, buffer); };
+
+  ExpectRealtimeDeath(Func, "setbuf");
+  ExpectNonRealtimeSurvival(Func);
+}
+
+TEST_F(RtsanFileTest, SetvbufDieWhenRealtime) {
+  char buffer[1024];
+  size_t size = sizeof(buffer);
+  FILE *f = fopen(GetTemporaryFilePath(), "w");
+  EXPECT_THAT(f, Ne(nullptr));
+
+  auto Func = [&f, &buffer, &size]() {
+    int r = setvbuf(f, buffer, _IOFBF, size);
+    EXPECT_THAT(r, Eq(0));
+  };
+
+  ExpectRealtimeDeath(Func, "setvbuf");
+  ExpectNonRealtimeSurvival(Func);
+}
+#endif
+
 class RtsanOpenedFileTest : public RtsanFileTest {
 protected:
   void SetUp() override {