[compiler-rt] [compiler-rt][rtsan] Linux's eventfd interception. (PR #132836)

[David CARLIER via llvm-commits]

https://github.com/devnexen created https://github.com/llvm/llvm-project/pull/132836

None

>From afe9a2efeaaa444755f2da000b3fa188ae988d87 Mon Sep 17 00:00:00 2001
From: David Carlier <devnexen at gmail.com>
Date: Mon, 24 Mar 2025 22:02:51 +0000
Subject: [PATCH] [compiler-rt][rtsan] Linux's eventfd interception.

---
 compiler-rt/lib/rtsan/rtsan_interceptors_posix.cpp       | 9 +++++++++
 .../lib/rtsan/tests/rtsan_test_interceptors_posix.cpp    | 7 +++++++
 2 files changed, 16 insertions(+)

diff --git a/compiler-rt/lib/rtsan/rtsan_interceptors_posix.cpp b/compiler-rt/lib/rtsan/rtsan_interceptors_posix.cpp
index 9d1a689a5a070..aed43fcd92249 100644
--- a/compiler-rt/lib/rtsan/rtsan_interceptors_posix.cpp
+++ b/compiler-rt/lib/rtsan/rtsan_interceptors_posix.cpp
@@ -1359,6 +1359,12 @@ INTERCEPTOR(int, timerfd_gettime, int fd, struct itimerspec *val) {
   __rtsan_notify_intercepted_call("timerfd_gettime");
   return REAL(timerfd_gettime)(fd, val);
 }
+
+/* eventfd wrappers calls SYS_eventfd2 down the line */
+INTERCEPTOR(int, eventfd, unsigned int count, int flags) {
+  __rtsan_notify_intercepted_call("eventfd");
+  return REAL(eventfd)(count, flags);
+}
 #define RTSAN_MAYBE_INTERCEPT_INOTIFY_INIT INTERCEPT_FUNCTION(inotify_init)
 #define RTSAN_MAYBE_INTERCEPT_INOTIFY_INIT1 INTERCEPT_FUNCTION(inotify_init1)
 #define RTSAN_MAYBE_INTERCEPT_INOTIFY_ADD_WATCH                                \
@@ -1370,6 +1376,7 @@ INTERCEPTOR(int, timerfd_gettime, int fd, struct itimerspec *val) {
   INTERCEPT_FUNCTION(timerfd_settime)
 #define RTSAN_MAYBE_INTERCEPT_TIMERFD_GETTIME                                  \
   INTERCEPT_FUNCTION(timerfd_gettime)
+#define RTSAN_MAYBE_INTERCEPT_EVENTFD INTERCEPT_FUNCTION(eventfd)
 #else
 #define RTSAN_MAYBE_INTERCEPT_INOTIFY_INIT
 #define RTSAN_MAYBE_INTERCEPT_INOTIFY_INIT1
@@ -1378,6 +1385,7 @@ INTERCEPTOR(int, timerfd_gettime, int fd, struct itimerspec *val) {
 #define RTSAN_MAYBE_INTERCEPT_TIMERFD_CREATE
 #define RTSAN_MAYBE_INTERCEPT_TIMERFD_SETTIME
 #define RTSAN_MAYBE_INTERCEPT_TIMERFD_GETTIME
+#define RTSAN_MAYBE_INTERCEPT_EVENTFD
 #endif
 
 INTERCEPTOR(int, pipe, int pipefd[2]) {
@@ -1644,6 +1652,7 @@ void __rtsan::InitializeInterceptors() {
   RTSAN_MAYBE_INTERCEPT_TIMERFD_CREATE;
   RTSAN_MAYBE_INTERCEPT_TIMERFD_SETTIME;
   RTSAN_MAYBE_INTERCEPT_TIMERFD_GETTIME;
+  RTSAN_MAYBE_INTERCEPT_EVENTFD;
 
   INTERCEPT_FUNCTION(pipe);
   INTERCEPT_FUNCTION(mkfifo);
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..3a43f4f9c434c 100644
--- a/compiler-rt/lib/rtsan/tests/rtsan_test_interceptors_posix.cpp
+++ b/compiler-rt/lib/rtsan/tests/rtsan_test_interceptors_posix.cpp
@@ -44,6 +44,7 @@
 #include <pthread.h>
 #include <stdio.h>
 #if SANITIZER_LINUX
+#include <sys/eventfd.h>
 #include <sys/inotify.h>
 #include <sys/timerfd.h>
 #endif
@@ -1677,6 +1678,12 @@ TEST(TestRtsanInterceptors, TimerfdGettimeDiesWhenRealtime) {
   ExpectRealtimeDeath(Func, "timerfd_gettime");
   ExpectNonRealtimeSurvival(Func);
 }
+
+TEST(TestRtsanInterceptors, EventfdDiesWhenRealtime) {
+  auto Func = []() { eventfd(EFD_CLOEXEC, 0); };
+  ExpectRealtimeDeath(Func, "eventfd");
+  ExpectNonRealtimeSurvival(Func);
+}
 #endif
 
 TEST(TestRtsanInterceptors, MkfifoDiesWhenRealtime) {