[compiler-rt] [compiler-rt][rtsan] signalfd interception for Linux. (PR #135491)

[via llvm-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-compiler-rt-sanitizer

Author: David CARLIER (devnexen)

<details>
<summary>Changes</summary>



---
Full diff: https://github.com/llvm/llvm-project/pull/135491.diff


2 Files Affected:

- (modified) compiler-rt/lib/rtsan/rtsan_interceptors_posix.cpp (+16) 
- (modified) compiler-rt/lib/rtsan/tests/rtsan_test_interceptors_posix.cpp (+11) 


``````````diff
diff --git a/compiler-rt/lib/rtsan/rtsan_interceptors_posix.cpp b/compiler-rt/lib/rtsan/rtsan_interceptors_posix.cpp
index e8cea21ddf9aa..fa194c1132502 100644
--- a/compiler-rt/lib/rtsan/rtsan_interceptors_posix.cpp
+++ b/compiler-rt/lib/rtsan/rtsan_interceptors_posix.cpp
@@ -1456,6 +1456,20 @@ INTERCEPTOR(ssize_t, process_vm_writev, pid_t pid,
 #define RTSAN_MAYBE_INTERCEPT_PROCESS_VM_WRITEV
 #endif
 
+// Signals
+
+#if SANITIZER_LINUX
+/* same as eventfd, signalfd calls SYS_signalfd4 to support the flags argument
+ */
+INTERCEPTOR(int, signalfd, const sigset_t *mask, int flags) {
+  __rtsan_notify_intercepted_call("signalfd");
+  return REAL(signalfd)(mask, flags);
+}
+#define RTSAN_MAYBE_INTERCEPT_SIGNALFD INTERCEPT_FUNCTION(signalfd)
+#else
+#define RTSAN_MAYBE_INTERCEPT_SIGNALFD
+#endif
+
 // TODO: the `wait` family of functions is an oddity. In testing, if you
 // intercept them, Darwin seemingly ignores them, and linux never returns from
 // the test. Revisit this in the future, but hopefully intercepting fork/exec is
@@ -1676,6 +1690,8 @@ void __rtsan::InitializeInterceptors() {
   RTSAN_MAYBE_INTERCEPT_PROCESS_VM_READV;
   RTSAN_MAYBE_INTERCEPT_PROCESS_VM_WRITEV;
 
+  RTSAN_MAYBE_INTERCEPT_SIGNALFD;
+
   INTERCEPT_FUNCTION(syscall);
 }
 
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 048da5858d665..31f0e58de7538 100644
--- a/compiler-rt/lib/rtsan/tests/rtsan_test_interceptors_posix.cpp
+++ b/compiler-rt/lib/rtsan/tests/rtsan_test_interceptors_posix.cpp
@@ -46,6 +46,7 @@
 #if SANITIZER_LINUX
 #include <sys/eventfd.h>
 #include <sys/inotify.h>
+#include <sys/signalfd.h>
 #include <sys/timerfd.h>
 #endif
 #include <sys/ioctl.h>
@@ -821,6 +822,16 @@ TEST(TestRtsanInterceptors, ProcessVmWritevDiesWhenRealtime) {
 }
 #endif
 
+#if SANITIZER_LINUX
+TEST(TestRtsanInterceptors, SignalfdDiesWhenRealtime) {
+  sigset_t set;
+  sigemptyset(&set);
+  auto Func = [&set]() { signalfd(-1, &set, 0); };
+  ExpectRealtimeDeath(Func, "signalfd");
+  ExpectNonRealtimeSurvival(Func);
+}
+#endif
+
 class RtsanDirectoryTest : public ::testing::Test {
 protected:
   void SetUp() override {

``````````

</details>


https://github.com/llvm/llvm-project/pull/135491