[compiler-rt] [compiler-rt][rtsan] symlink/symlinkat interception. (PR #134168)

[David CARLIER via llvm-commits]

https://github.com/devnexen created https://github.com/llvm/llvm-project/pull/134168

None

>From 85d97babdde013944cde0486be25eebf8cf85ca2 Mon Sep 17 00:00:00 2001
From: David Carlier <devnexen at gmail.com>
Date: Wed, 2 Apr 2025 23:45:58 +0100
Subject: [PATCH] [compiler-rt][rtsan] symlink/symlinkat interception.

---
 .../lib/rtsan/rtsan_interceptors_posix.cpp       | 13 +++++++++++++
 .../tests/rtsan_test_interceptors_posix.cpp      | 16 ++++++++++++++++
 2 files changed, 29 insertions(+)

diff --git a/compiler-rt/lib/rtsan/rtsan_interceptors_posix.cpp b/compiler-rt/lib/rtsan/rtsan_interceptors_posix.cpp
index 9d1a689a5a070..61d413a3f1762 100644
--- a/compiler-rt/lib/rtsan/rtsan_interceptors_posix.cpp
+++ b/compiler-rt/lib/rtsan/rtsan_interceptors_posix.cpp
@@ -322,6 +322,17 @@ INTERCEPTOR(int, ftruncate64, int fd, off64_t length) {
 #define RTSAN_MAYBE_INTERCEPT_FTRUNCATE64
 #endif
 
+INTERCEPTOR(int, symlink, const char *target, const char *linkpath) {
+  __rtsan_notify_intercepted_call("symlink");
+  return REAL(symlink)(target, linkpath);
+}
+
+INTERCEPTOR(int, symlinkat, const char *target, int newdirfd,
+            const char *linkpath) {
+  __rtsan_notify_intercepted_call("symlinkat");
+  return REAL(symlinkat)(target, newdirfd, linkpath);
+}
+
 // Streams
 
 INTERCEPTOR(FILE *, fopen, const char *path, const char *mode) {
@@ -1515,6 +1526,8 @@ void __rtsan::InitializeInterceptors() {
   RTSAN_MAYBE_INTERCEPT_READLINKAT;
   INTERCEPT_FUNCTION(unlink);
   INTERCEPT_FUNCTION(unlinkat);
+  INTERCEPT_FUNCTION(symlink);
+  INTERCEPT_FUNCTION(symlinkat);
   INTERCEPT_FUNCTION(truncate);
   INTERCEPT_FUNCTION(ftruncate);
   RTSAN_MAYBE_INTERCEPT_TRUNCATE64;
diff --git a/compiler-rt/lib/rtsan/tests/rtsan_test_interceptors_posix.cpp b/compiler-rt/lib/rtsan/tests/rtsan_test_interceptors_posix.cpp
index f12df9ea90855..3b6c38a2fba11 100644
--- a/compiler-rt/lib/rtsan/tests/rtsan_test_interceptors_posix.cpp
+++ b/compiler-rt/lib/rtsan/tests/rtsan_test_interceptors_posix.cpp
@@ -896,6 +896,22 @@ TEST_F(RtsanOpenedFileTest, FtruncateDiesWhenRealtime) {
   ExpectNonRealtimeSurvival(Func);
 }
 
+TEST_F(RtsanOpenedFileTest, SymlinkDiesWhenRealtime) {
+  auto Func = [&]() {
+    symlink("/tmp/rtsan_symlink_test", GetTemporaryFilePath());
+  };
+  ExpectRealtimeDeath(Func, "symlink");
+  ExpectNonRealtimeSurvival(Func);
+}
+
+TEST_F(RtsanOpenedFileTest, SymlinkatDiesWhenRealtime) {
+  auto Func = [&]() {
+    symlinkat("/tmp/rtsan_symlinkat_test", AT_FDCWD, GetTemporaryFilePath());
+  };
+  ExpectRealtimeDeath(Func, "symlinkat");
+  ExpectNonRealtimeSurvival(Func);
+}
+
 TEST_F(RtsanFileTest, FcloseDiesWhenRealtime) {
   FILE *f = fopen(GetTemporaryFilePath(), "w");
   EXPECT_THAT(f, Ne(nullptr));