[compiler-rt] [rtsan] Add more file descriptor interceptors - dup*, lseek (PR #116853)

[Chris Apple via llvm-commits]

https://github.com/cjappl created https://github.com/llvm/llvm-project/pull/116853

# Why we think these are real-time unsafe

They correspond directly to system calls in linux and OSX, they are manipulating a shared resource, which likely takes some operating-system synchronization.



>From e6a0c958aa4548b8e3a8bfc14ab9d34ac0bf8b84 Mon Sep 17 00:00:00 2001
From: Chris Apple <cja-private at pm.me>
Date: Tue, 19 Nov 2024 10:14:49 -0800
Subject: [PATCH] [rtsan] Add more file descriptor interceptors - dup*, lseek

---
 .../lib/rtsan/rtsan_interceptors_posix.cpp    | 29 +++++++++++++++++++
 .../tests/rtsan_test_interceptors_posix.cpp   | 18 ++++++++++++
 .../sanitizer_platform_interceptors.h         |  2 ++
 3 files changed, 49 insertions(+)

diff --git a/compiler-rt/lib/rtsan/rtsan_interceptors_posix.cpp b/compiler-rt/lib/rtsan/rtsan_interceptors_posix.cpp
index 497db4ecc6ef4c..d18ebb57fc2f75 100644
--- a/compiler-rt/lib/rtsan/rtsan_interceptors_posix.cpp
+++ b/compiler-rt/lib/rtsan/rtsan_interceptors_posix.cpp
@@ -316,6 +316,31 @@ INTERCEPTOR(ssize_t, writev, int fd, const struct iovec *iov, int iovcnt) {
   return REAL(writev)(fd, iov, iovcnt);
 }
 
+INTERCEPTOR(off_t, lseek, int fd, off_t offset, int whence) {
+  __rtsan_notify_intercepted_call("lseek");
+  return REAL(lseek)(fd, offset, whence);
+}
+
+#if SANITIZER_INTERCEPT_LSEEK64
+INTERCEPTOR(off64_t, lseek64, int fd, off64_t offset, int whence) {
+  __rtsan_notify_intercepted_call("lseek64");
+  return REAL(lseek64)(fd, offset, whence);
+}
+#define RTSAN_MAYBE_INTERCEPT_LSEEK64 INTERCEPT_FUNCTION(lseek64)
+#else
+#define RTSAN_MAYBE_INTERCEPT_LSEEK64
+#endif // SANITIZER_INTERCEPT_LSEEK64
+
+INTERCEPTOR(int, dup, int oldfd) {
+  __rtsan_notify_intercepted_call("dup");
+  return REAL(dup)(oldfd);
+}
+
+INTERCEPTOR(int, dup2, int oldfd, int newfd) {
+  __rtsan_notify_intercepted_call("dup2");
+  return REAL(dup2)(oldfd, newfd);
+}
+
 // Concurrency
 #if SANITIZER_APPLE
 #pragma clang diagnostic push
@@ -757,6 +782,10 @@ void __rtsan::InitializeInterceptors() {
   RTSAN_MAYBE_INTERCEPT_CREAT64;
   INTERCEPT_FUNCTION(puts);
   INTERCEPT_FUNCTION(fputs);
+  INTERCEPT_FUNCTION(lseek);
+  RTSAN_MAYBE_INTERCEPT_LSEEK64;
+  INTERCEPT_FUNCTION(dup);
+  INTERCEPT_FUNCTION(dup2);
 
 #if SANITIZER_APPLE
   INTERCEPT_FUNCTION(OSSpinLockLock);
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 5be62b97906383..ab02b44187d89e 100644
--- a/compiler-rt/lib/rtsan/tests/rtsan_test_interceptors_posix.cpp
+++ b/compiler-rt/lib/rtsan/tests/rtsan_test_interceptors_posix.cpp
@@ -367,6 +367,24 @@ class RtsanOpenedFileTest : public RtsanFileTest {
   int fd = -1;
 };
 
+TEST_F(RtsanOpenedFileTest, LseekDiesWhenRealtime) {
+  auto Func = [this]() { lseek(GetOpenFd(), 0, SEEK_SET); };
+  ExpectRealtimeDeath(Func, MAYBE_APPEND_64("lseek"));
+  ExpectNonRealtimeSurvival(Func);
+}
+
+TEST_F(RtsanOpenedFileTest, DupDiesWhenRealtime) {
+  auto Func = [this]() { dup(GetOpenFd()); };
+  ExpectRealtimeDeath(Func, "dup");
+  ExpectNonRealtimeSurvival(Func);
+}
+
+TEST_F(RtsanOpenedFileTest, Dup2DiesWhenRealtime) {
+  auto Func = [this]() { dup2(GetOpenFd(), 0); };
+  ExpectRealtimeDeath(Func, "dup2");
+  ExpectNonRealtimeSurvival(Func);
+}
+
 TEST_F(RtsanOpenedFileTest, FreadDiesWhenRealtime) {
   auto Func = [this]() {
     char c{};
diff --git a/compiler-rt/lib/sanitizer_common/sanitizer_platform_interceptors.h b/compiler-rt/lib/sanitizer_common/sanitizer_platform_interceptors.h
index 7f9d4998bf757c..9db29cd23458d9 100644
--- a/compiler-rt/lib/sanitizer_common/sanitizer_platform_interceptors.h
+++ b/compiler-rt/lib/sanitizer_common/sanitizer_platform_interceptors.h
@@ -210,6 +210,8 @@ SANITIZER_WEAK_IMPORT void *aligned_alloc(__sanitizer::usize __alignment,
 #define SANITIZER_INTERCEPT_PREAD64 (SI_GLIBC || SI_SOLARIS32)
 #define SANITIZER_INTERCEPT_PWRITE64 (SI_GLIBC || SI_SOLARIS32)
 
+#define SANITIZER_INTERCEPT_LSEEK64 (SI_GLIBC || SI_SOLARIS32)
+
 #define SANITIZER_INTERCEPT_READV SI_POSIX
 #define SANITIZER_INTERCEPT_WRITEV SI_POSIX