[PATCH] Cherry-pick upstream r299036 from libsanitizer (PR sanitizer/80166).

[Martin Liška]

Hello.

Cherry-picking the commit to fix PR reported originally to the GCC.
Ready to install after it finishes regression tests?

Thanks,
Martin

>From 36cc9827dd47f213bb17dd7e37b3b19b740a0928 Mon Sep 17 00:00:00 2001
From: marxin <mli...@suse.cz>
Date: Fri, 31 Mar 2017 10:28:25 +0200
Subject: [PATCH] Cherry-pick upstream r299036 from libsanitizer (PR
 sanitizer/80166).

libsanitizer/ChangeLog:

2017-03-31  Martin Liska  <mli...@suse.cz>

	* sanitizer_common/sanitizer_common_interceptors.inc (INTERCEPTOR):
	Cherry-pick upstream r299036.

gcc/testsuite/ChangeLog:

2017-03-31  Martin Liska  <mli...@suse.cz>

	* gcc.dg/asan/pr80166.c: New test.
---
 gcc/testsuite/gcc.dg/asan/pr80166.c                | 24 ++++++++++++++++++++++
 .../sanitizer_common_interceptors.inc              |  3 ++-
 2 files changed, 26 insertions(+), 1 deletion(-)
 create mode 100644 gcc/testsuite/gcc.dg/asan/pr80166.c

diff --git a/gcc/testsuite/gcc.dg/asan/pr80166.c b/gcc/testsuite/gcc.dg/asan/pr80166.c
new file mode 100644
index 00000000000..629dd23a31c
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/asan/pr80166.c
@@ -0,0 +1,24 @@
+/* PR sanitizer/80166 */
+/* { dg-do run } */
+
+#include <sys/types.h>
+#include <unistd.h>
+
+int
+main (int argc, char **argv)
+{
+  gid_t groups;
+  int r = getgroups (0, &groups);
+  if (r < 0)
+    __builtin_abort ();
+
+  r = getgroups (-1, &groups);
+  if (r != -1)
+    __builtin_abort ();
+
+  r = getgroups (-1, NULL);
+  if (r != -1)
+    __builtin_abort ();
+
+  return 0;
+}
diff --git a/libsanitizer/sanitizer_common/sanitizer_common_interceptors.inc b/libsanitizer/sanitizer_common/sanitizer_common_interceptors.inc
index 0970eda5ee6..195014022a0 100644
--- a/libsanitizer/sanitizer_common/sanitizer_common_interceptors.inc
+++ b/libsanitizer/sanitizer_common/sanitizer_common_interceptors.inc
@@ -3350,7 +3350,8 @@ INTERCEPTOR(int, getgroups, int size, u32 *lst) {
   // its metadata. See
   // https://github.com/google/sanitizers/issues/321.
   int res = REAL(getgroups)(size, lst);
-  if (res && lst) COMMON_INTERCEPTOR_WRITE_RANGE(ctx, lst, res * sizeof(*lst));
+  if (res >= 0 && lst && size > 0)
+    COMMON_INTERCEPTOR_WRITE_RANGE(ctx, lst, res * sizeof(*lst));
   return res;
 }
 #define INIT_GETGROUPS COMMON_INTERCEPT_FUNCTION(getgroups);
-- 
2.12.0