tsan: add a comment to CallUserSignalHandler
Reviewed By: melver
Differential Revision: https://reviews.llvm.org/D108907
diff --git a/compiler-rt/lib/tsan/rtl/tsan_interceptors_posix.cpp b/compiler-rt/lib/tsan/rtl/tsan_interceptors_posix.cpp
index 788f227..570ad89 100644
--- a/compiler-rt/lib/tsan/rtl/tsan_interceptors_posix.cpp
+++ b/compiler-rt/lib/tsan/rtl/tsan_interceptors_posix.cpp
@@ -1989,8 +1989,12 @@
volatile uptr pc = (sigactions[sig].sa_flags & SA_SIGINFO)
? (uptr)sigactions[sig].sigaction
: (uptr)sigactions[sig].handler;
- if (pc != sig_dfl && pc != sig_ign)
+ if (pc != sig_dfl && pc != sig_ign) {
+ // The callback can be either sa_handler or sa_sigaction.
+ // They have different signatures, but we assume that passing
+ // additional arguments to sa_handler works and is harmless.
((__sanitizer_sigactionhandler_ptr)pc)(sig, info, uctx);
+ }
if (!ctx->after_multithreaded_fork) {
thr->ignore_reads_and_writes = ignore_reads_and_writes;
if (ignore_reads_and_writes)
