[DFSan] Add custom wrapper for sigaltstack.

The wrapper clears shadow for old_ss.

Reviewed By: stephan.yichao.zhao

Differential Revision: https://reviews.llvm.org/D93041

diff --git a/compiler-rt/lib/dfsan/dfsan_custom.cpp b/compiler-rt/lib/dfsan/dfsan_custom.cpp
index 576f7f6..b43f978 100644 (file)
--- a/compiler-rt/lib/dfsan/dfsan_custom.cpp
+++ b/compiler-rt/lib/dfsan/dfsan_custom.cpp
@@ -800,6 +800,16 @@ int __dfsw_sigaction(int signum, const struct sigaction *act,
 }
 
 SANITIZER_INTERFACE_ATTRIBUTE
+int __dfsw_sigaltstack(const stack_t *ss, stack_t *old_ss, dfsan_label ss_label,
+                       dfsan_label old_ss_label, dfsan_label *ret_label) {
+  int ret = sigaltstack(ss, old_ss);
+  if (ret != -1 && old_ss)
+    dfsan_set_label(0, old_ss, sizeof(*old_ss));
+  *ret_label = 0;
+  return ret;
+}
+
+SANITIZER_INTERFACE_ATTRIBUTE
 int __dfsw_gettimeofday(struct timeval *tv, struct timezone *tz,
                         dfsan_label tv_label, dfsan_label tz_label,
                         dfsan_label *ret_label) {

diff --git a/compiler-rt/lib/dfsan/done_abilist.txt b/compiler-rt/lib/dfsan/done_abilist.txt
index 9a92098..b8cfa3b 100644 (file)
--- a/compiler-rt/lib/dfsan/done_abilist.txt
+++ b/compiler-rt/lib/dfsan/done_abilist.txt
@@ -200,6 +200,7 @@ fun:nanosleep=custom
 fun:pread=custom
 fun:read=custom
 fun:recvmsg=custom
+fun:sigaltstack=custom
 fun:socketpair=custom
 fun:stat=custom
 fun:time=custom

diff --git a/compiler-rt/test/dfsan/custom.cpp b/compiler-rt/test/dfsan/custom.cpp
index 8305941..a03f33f 100644 (file)
--- a/compiler-rt/test/dfsan/custom.cpp
+++ b/compiler-rt/test/dfsan/custom.cpp
@@ -762,6 +762,15 @@ void test_sigaction() {
   ASSERT_READ_ZERO_LABEL(&oldact, sizeof(oldact));
 }
 
+void test_sigaltstack() {
+  stack_t old_altstack = {};
+  dfsan_set_label(j_label, &old_altstack, sizeof(old_altstack));
+  int ret = sigaltstack(NULL, &old_altstack);
+  assert(ret == 0);
+  ASSERT_ZERO_LABEL(ret);
+  ASSERT_READ_ZERO_LABEL(&old_altstack, sizeof(old_altstack));
+}
+
 void test_gettimeofday() {
   struct timeval tv;
   struct timezone tz;
@@ -1172,6 +1181,7 @@ int main(void) {
   test_sched_getaffinity();
   test_select();
   test_sigaction();
+  test_sigaltstack();
   test_sigemptyset();
   test_snprintf();
   test_socketpair();