[compiler-rt] [compiler-rt][rtsan] memffd_create for linux interception. (PR #132571)

[David CARLIER via llvm-commits]

https://github.com/devnexen created https://github.com/llvm/llvm-project/pull/132571

None

>From cd96fb100df2e845deedc2d02ee20f93853332eb Mon Sep 17 00:00:00 2001
From: David Carlier <devnexen at gmail.com>
Date: Sat, 22 Mar 2025 22:47:56 +0000
Subject: [PATCH] [compiler-rt][rtsan] memffd_create for linux interception.

---
 compiler-rt/lib/rtsan/rtsan_interceptors_posix.cpp   | 12 ++++++++++++
 .../rtsan/tests/rtsan_test_interceptors_posix.cpp    |  8 ++++++++
 2 files changed, 20 insertions(+)

diff --git a/compiler-rt/lib/rtsan/rtsan_interceptors_posix.cpp b/compiler-rt/lib/rtsan/rtsan_interceptors_posix.cpp
index f093862462796..b139f628703f9 100644
--- a/compiler-rt/lib/rtsan/rtsan_interceptors_posix.cpp
+++ b/compiler-rt/lib/rtsan/rtsan_interceptors_posix.cpp
@@ -1031,6 +1031,17 @@ INTERCEPTOR(int, shm_unlink, const char *name) {
   return REAL(shm_unlink)(name);
 }
 
+#if !SANITIZER_APPLE
+// is supported by freebsd too
+INTERCEPTOR(int, memfd_create, const char *path, unsigned int flags) {
+  __rtsan_notify_intercepted_call("memfd_create");
+  return REAL(memfd_create)(path, flags);
+}
+#define RTSAN_MAYBE_INTERCEPT_MEMFD_CREATE INTERCEPT_FUNCTION(memfd_create)
+#else
+#define RTSAN_MAYBE_INTERCEPT_MEMFD_CREATE
+#endif
+
 // Sockets
 INTERCEPTOR(int, getaddrinfo, const char *node, const char *service,
             const struct addrinfo *hints, struct addrinfo **res) {
@@ -1465,6 +1476,7 @@ void __rtsan::InitializeInterceptors() {
   INTERCEPT_FUNCTION(mincore);
   INTERCEPT_FUNCTION(shm_open);
   INTERCEPT_FUNCTION(shm_unlink);
+  RTSAN_MAYBE_INTERCEPT_MEMFD_CREATE;
   RTSAN_MAYBE_INTERCEPT_MEMALIGN;
   RTSAN_MAYBE_INTERCEPT_PVALLOC;
 
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 9ef6887a9c848..321cc4f0c78f1 100644
--- a/compiler-rt/lib/rtsan/tests/rtsan_test_interceptors_posix.cpp
+++ b/compiler-rt/lib/rtsan/tests/rtsan_test_interceptors_posix.cpp
@@ -302,6 +302,14 @@ TEST(TestRtsanInterceptors, ShmUnlinkDiesWhenRealtime) {
   ExpectNonRealtimeSurvival(Func);
 }
 
+#if !SANITIZER_APPLE
+TEST(TestRtsanInterceptors, MemfdCreateDiesWhenRealtime) {
+  auto Func = []() { memfd_create("/rtsan_test_memfd_create", MFD_CLOEXEC); };
+  ExpectRealtimeDeath(Func, "memfd_create");
+  ExpectNonRealtimeSurvival(Func);
+}
+#endif
+
 /*
     Sleeping
 */