[sanitizer] Add syscall handlers for sigaction and rt_sigaction.

llvm-svn: 273746

3 files changed, 92 insertions, 5 deletions

diff --git a/compiler-rt/include/sanitizer/linux_syscall_hooks.h b/compiler-rt/include/sanitizer/linux_syscall_hooks.h
index 89867c15190..09f261dd672 100644
--- a/compiler-rt/include/sanitizer/linux_syscall_hooks.h
+++ b/compiler-rt/include/sanitizer/linux_syscall_hooks.h
@@ -1835,6 +1835,17 @@
   __sanitizer_syscall_pre_impl_vfork()
 #define __sanitizer_syscall_post_vfork(res) \
   __sanitizer_syscall_post_impl_vfork(res)
+#define __sanitizer_syscall_pre_sigaction(signum, act, oldact)                 \
+  __sanitizer_syscall_pre_impl_sigaction((long)signum, (long)act, (long)oldact)
+#define __sanitizer_syscall_post_sigaction(res, signum, act, oldact)           \
+  __sanitizer_syscall_post_impl_sigaction(res, (long)signum, (long)act,        \
+                                          (long)oldact)
+#define __sanitizer_syscall_pre_rt_sigaction(signum, act, oldact, sz)          \
+  __sanitizer_syscall_pre_impl_rt_sigaction((long)signum, (long)act,           \
+                                            (long)oldact, (long)sz)
+#define __sanitizer_syscall_post_rt_sigaction(res, signum, act, oldact, sz)    \
+  __sanitizer_syscall_post_impl_rt_sigaction(res, (long)signum, (long)act,     \
+                                             (long)oldact, (long)sz)
 
 // And now a few syscalls we don't handle yet.
 #define __sanitizer_syscall_pre_afs_syscall(...)
@@ -1889,7 +1900,6 @@
 #define __sanitizer_syscall_pre_query_module(...)
 #define __sanitizer_syscall_pre_readahead(...)
 #define __sanitizer_syscall_pre_readdir(...)
-#define __sanitizer_syscall_pre_rt_sigaction(...)
 #define __sanitizer_syscall_pre_rt_sigreturn(...)
 #define __sanitizer_syscall_pre_rt_sigsuspend(...)
 #define __sanitizer_syscall_pre_security(...)
@@ -1903,7 +1913,6 @@
 #define __sanitizer_syscall_pre_setreuid32(...)
 #define __sanitizer_syscall_pre_set_thread_area(...)
 #define __sanitizer_syscall_pre_setuid32(...)
-#define __sanitizer_syscall_pre_sigaction(...)
 #define __sanitizer_syscall_pre_sigaltstack(...)
 #define __sanitizer_syscall_pre_sigreturn(...)
 #define __sanitizer_syscall_pre_sigsuspend(...)
@@ -1971,7 +1980,6 @@
 #define __sanitizer_syscall_post_query_module(res, ...)
 #define __sanitizer_syscall_post_readahead(res, ...)
 #define __sanitizer_syscall_post_readdir(res, ...)
-#define __sanitizer_syscall_post_rt_sigaction(res, ...)
 #define __sanitizer_syscall_post_rt_sigreturn(res, ...)
 #define __sanitizer_syscall_post_rt_sigsuspend(res, ...)
 #define __sanitizer_syscall_post_security(res, ...)
@@ -1985,7 +1993,6 @@
 #define __sanitizer_syscall_post_setreuid32(res, ...)
 #define __sanitizer_syscall_post_set_thread_area(res, ...)
 #define __sanitizer_syscall_post_setuid32(res, ...)
-#define __sanitizer_syscall_post_sigaction(res, ...)
 #define __sanitizer_syscall_post_sigaltstack(res, ...)
 #define __sanitizer_syscall_post_sigreturn(res, ...)
 #define __sanitizer_syscall_post_sigsuspend(res, ...)
@@ -3062,7 +3069,13 @@ void __sanitizer_syscall_pre_impl_fork();
 void __sanitizer_syscall_post_impl_fork(long res);
 void __sanitizer_syscall_pre_impl_vfork();
 void __sanitizer_syscall_post_impl_vfork(long res);
-
+void __sanitizer_syscall_pre_impl_sigaction(long signum, long act, long oldact);
+void __sanitizer_syscall_post_impl_sigaction(long res, long signum, long act,
+                                             long oldact);
+void __sanitizer_syscall_pre_impl_rt_sigaction(long signum, long act,
+                                               long oldact, long sz);
+void __sanitizer_syscall_post_impl_rt_sigaction(long res, long signum, long act,
+                                                long oldact, long sz);
 #ifdef __cplusplus
 }  // extern "C"
 #endif
diff --git a/compiler-rt/lib/sanitizer_common/sanitizer_common_syscalls.inc b/compiler-rt/lib/sanitizer_common/sanitizer_common_syscalls.inc
index 48016f218f3..469c8eb7e14 100644
--- a/compiler-rt/lib/sanitizer_common/sanitizer_common_syscalls.inc
+++ b/compiler-rt/lib/sanitizer_common/sanitizer_common_syscalls.inc
@@ -2840,6 +2840,40 @@ PRE_SYSCALL(vfork)() {
 POST_SYSCALL(vfork)(long res) {
   COMMON_SYSCALL_POST_FORK(res);
 }
+
+PRE_SYSCALL(sigaction)(long signum, const __sanitizer_kernel_sigaction_t *act,
+                       __sanitizer_kernel_sigaction_t *oldact) {
+  if (act) {
+    PRE_READ(&act->sigaction, sizeof(act->sigaction));
+    PRE_READ(&act->sa_flags, sizeof(act->sa_flags));
+    PRE_READ(&act->sa_mask, sizeof(act->sa_mask));
+  }
+}
+
+POST_SYSCALL(sigaction)(long res, long signum,
+                        const __sanitizer_kernel_sigaction_t *act,
+                        __sanitizer_kernel_sigaction_t *oldact) {
+  if (res >= 0 && oldact) POST_WRITE(oldact, sizeof(*oldact));
+}
+
+PRE_SYSCALL(rt_sigaction)(long signum,
+                          const __sanitizer_kernel_sigaction_t *act,
+                          __sanitizer_kernel_sigaction_t *oldact, SIZE_T sz) {
+  if (act) {
+    PRE_READ(&act->sigaction, sizeof(act->sigaction));
+    PRE_READ(&act->sa_flags, sizeof(act->sa_flags));
+    PRE_READ(&act->sa_mask, sz);
+  }
+}
+
+POST_SYSCALL(rt_sigaction)(long res, long signum,
+                           const __sanitizer_kernel_sigaction_t *act,
+                           __sanitizer_kernel_sigaction_t *oldact, SIZE_T sz) {
+  if (res >= 0 && oldact) {
+    SIZE_T oldact_sz = ((char *)&oldact->sa_mask) - ((char *)oldact) + sz;
+    POST_WRITE(oldact, oldact_sz);
+  }
+}
 }  // extern "C"
 
 #undef PRE_SYSCALL
diff --git a/compiler-rt/test/msan/Linux/syscalls_sigaction.cc b/compiler-rt/test/msan/Linux/syscalls_sigaction.cc
new file mode 100644
index 00000000000..1297fae13d1
--- /dev/null
+++ b/compiler-rt/test/msan/Linux/syscalls_sigaction.cc
@@ -0,0 +1,40 @@
+// RUN: %clangxx_msan -DPRE1 -O0 %s -o %t && not %run %t 2>&1
+// RUN: %clangxx_msan -DPRE2 -O0 %s -o %t && not %run %t 2>&1
+// RUN: %clangxx_msan -DPRE3 -O0 %s -o %t && not %run %t 2>&1
+// RUN: %clangxx_msan -O0 %s -o %t && %run %t 2>&1
+
+#include <assert.h>
+#include <signal.h>
+#include <string.h>
+
+#include <sanitizer/linux_syscall_hooks.h>
+#include <sanitizer/msan_interface.h>
+
+struct my_kernel_sigaction {
+  long handler, flags, restorer;
+  uint64_t mask[20]; // larger than any known platform
+};
+
+int main() {
+  my_kernel_sigaction act = {}, oldact = {};
+
+#if defined(PRE1)
+  __msan_poison(&act.handler, sizeof(act.handler));
+  __sanitizer_syscall_pre_rt_sigaction(SIGUSR1, &act, &oldact, 20 * 8);
+#elif defined(PRE2)
+  __msan_poison(&act.flags, sizeof(act.flags));
+  __sanitizer_syscall_pre_rt_sigaction(SIGUSR1, &act, &oldact, 20 * 8);
+#elif defined(PRE3)
+  __msan_poison(&act.mask, 1);
+  __sanitizer_syscall_pre_rt_sigaction(SIGUSR1, &act, &oldact, 20 * 8);
+#else
+  // Uninit past the end of the mask is ignored.
+  __msan_poison(((char *)&act.mask) + 5, 1);
+  __sanitizer_syscall_pre_rt_sigaction(SIGUSR1, &act, &oldact, 5);
+
+  memset(&act, 0, sizeof(act));
+  __msan_poison(&oldact, sizeof(oldact));
+  __sanitizer_syscall_post_rt_sigaction(0, SIGUSR1, &act, &oldact, 5);
+  assert(__msan_test_shadow(&oldact, sizeof(oldact)) == sizeof(long)*3 + 5);
+#endif
+}