[compiler-rt] fbcdf4a - tsan: intercept epoll_pwait2

[Dmitry Vyukov via llvm-commits]

Author: Dmitry Vyukov
Date: 2022-11-24T07:27:09+01:00
New Revision: fbcdf4a4fb9e51039877cc92bb18407416a158d7

URL: https://github.com/llvm/llvm-project/commit/fbcdf4a4fb9e51039877cc92bb18407416a158d7
DIFF: https://github.com/llvm/llvm-project/commit/fbcdf4a4fb9e51039877cc92bb18407416a158d7.diff

LOG: tsan: intercept epoll_pwait2

It's a new syscall similar to epoll_pwait.
Add a similar interceptor for it and add synchronization
annotations in epoll_wait* syscall wrappers.
Testing this is problematic b/c it's not present in glibc
and the syscall itself may not be supported by the kernel.

Reviewed By: melver

Differential Revision: https://reviews.llvm.org/D138574

Added: 
    

Modified: 
    compiler-rt/lib/sanitizer_common/sanitizer_common_syscalls.inc
    compiler-rt/lib/tsan/rtl/tsan_interceptors_posix.cpp

Removed: 
    


################################################################################
diff  --git a/compiler-rt/lib/sanitizer_common/sanitizer_common_syscalls.inc b/compiler-rt/lib/sanitizer_common/sanitizer_common_syscalls.inc
index 8c1ff7f65da47..e7cf7cfca1935 100644
--- a/compiler-rt/lib/sanitizer_common/sanitizer_common_syscalls.inc
+++ b/compiler-rt/lib/sanitizer_common/sanitizer_common_syscalls.inc
@@ -2106,6 +2106,7 @@ PRE_SYSCALL(epoll_wait)
 POST_SYSCALL(epoll_wait)
 (long res, long epfd, void *events, long maxevents, long timeout) {
   if (res >= 0) {
+    COMMON_SYSCALL_FD_ACQUIRE(epfd);
     if (events)
       POST_WRITE(events, res * struct_epoll_event_sz);
   }
@@ -2122,6 +2123,7 @@ POST_SYSCALL(epoll_pwait)
 (long res, long epfd, void *events, long maxevents, long timeout,
  const void *sigmask, long sigsetsize) {
   if (res >= 0) {
+    COMMON_SYSCALL_FD_ACQUIRE(epfd);
     if (events)
       POST_WRITE(events, res * struct_epoll_event_sz);
   }
@@ -2142,6 +2144,7 @@ POST_SYSCALL(epoll_pwait2)
  const sanitizer_kernel_timespec *timeout, const void *sigmask,
  long sigsetsize) {
   if (res >= 0) {
+    COMMON_SYSCALL_FD_ACQUIRE(epfd);
     if (events)
       POST_WRITE(events, res * struct_epoll_event_sz);
   }

diff  --git a/compiler-rt/lib/tsan/rtl/tsan_interceptors_posix.cpp b/compiler-rt/lib/tsan/rtl/tsan_interceptors_posix.cpp
index c557d5ddc6abc..72a771d762da6 100644
--- a/compiler-rt/lib/tsan/rtl/tsan_interceptors_posix.cpp
+++ b/compiler-rt/lib/tsan/rtl/tsan_interceptors_posix.cpp
@@ -1943,12 +1943,24 @@ TSAN_INTERCEPTOR(int, epoll_pwait, int epfd, void *ev, int cnt, int timeout,
   return res;
 }
 
-#define TSAN_MAYBE_INTERCEPT_EPOLL \
-    TSAN_INTERCEPT(epoll_create); \
-    TSAN_INTERCEPT(epoll_create1); \
-    TSAN_INTERCEPT(epoll_ctl); \
-    TSAN_INTERCEPT(epoll_wait); \
-    TSAN_INTERCEPT(epoll_pwait)
+TSAN_INTERCEPTOR(int, epoll_pwait2, int epfd, void *ev, int cnt, void *timeout,
+                 void *sigmask) {
+  SCOPED_TSAN_INTERCEPTOR(epoll_pwait2, epfd, ev, cnt, timeout, sigmask);
+  if (epfd >= 0)
+    FdAccess(thr, pc, epfd);
+  int res = BLOCK_REAL(epoll_pwait2)(epfd, ev, cnt, timeout, sigmask);
+  if (res > 0 && epfd >= 0)
+    FdAcquire(thr, pc, epfd);
+  return res;
+}
+
+#  define TSAN_MAYBE_INTERCEPT_EPOLL \
+    TSAN_INTERCEPT(epoll_create);    \
+    TSAN_INTERCEPT(epoll_create1);   \
+    TSAN_INTERCEPT(epoll_ctl);       \
+    TSAN_INTERCEPT(epoll_wait);      \
+    TSAN_INTERCEPT(epoll_pwait);     \
+    TSAN_INTERCEPT(epoll_pwait2)
 #else
 #define TSAN_MAYBE_INTERCEPT_EPOLL
 #endif