Avoid backtrace from __stack_chk_fail [BZ #12189]

__stack_chk_fail is called on corrupted stack.  Stack backtrace is very
unreliable against corrupted stack.  __libc_message is changed to accept
enum __libc_message_action and call BEFORE_ABORT only if action includes
do_backtrace.  __fortify_fail_abort is added to avoid backtrace from
__stack_chk_fail.

	[BZ #12189]
	* debug/Makefile (CFLAGS-tst-ssp-1.c): New.
	(tests): Add tst-ssp-1 if -fstack-protector works.
	* debug/fortify_fail.c: Include <stdbool.h>.
	(_fortify_fail_abort): New function.
	(__fortify_fail): Call _fortify_fail_abort.
	(__fortify_fail_abort): Add a hidden definition.
	* debug/stack_chk_fail.c: Include <stdbool.h>.
	(__stack_chk_fail): Call __fortify_fail_abort, instead of
	__fortify_fail.
	* debug/tst-ssp-1.c: New file.
	* include/stdio.h (__libc_message_action): New enum.
	(__libc_message): Replace int with enum __libc_message_action.
	(__fortify_fail_abort): New hidden prototype.
	* malloc/malloc.c (malloc_printerr): Update __libc_message calls.
	* sysdeps/posix/libc_fatal.c (__libc_message): Replace int
	with enum __libc_message_action.  Call BEFORE_ABORT only if
	action includes do_backtrace.
	(__libc_fatal): Update __libc_message call.

1 files changed, 6 insertions, 5 deletions

diff --git a/sysdeps/posix/libc_fatal.c b/sysdeps/posix/libc_fatal.c
index b261963679..25af8bd413 100644
--- a/sysdeps/posix/libc_fatal.c
+++ b/sysdeps/posix/libc_fatal.c
@@ -64,7 +64,7 @@ struct str_list
 
 /* Abort with an error message.  */
 void
-__libc_message (int do_abort, const char *fmt, ...)
+__libc_message (enum __libc_message_action action, const char *fmt, ...)
 {
   va_list ap;
   int fd = -1;
@@ -140,7 +140,7 @@ __libc_message (int do_abort, const char *fmt, ...)
 
       written = WRITEV_FOR_FATAL (fd, iov, nlist, total);
 
-      if (do_abort)
+      if ((action & do_abort))
 	{
 	  total = ((total + 1 + GLRO(dl_pagesize) - 1)
 		   & ~(GLRO(dl_pagesize) - 1));
@@ -167,9 +167,10 @@ __libc_message (int do_abort, const char *fmt, ...)
 
   va_end (ap);
 
-  if (do_abort)
+  if ((action & do_abort))
     {
-      BEFORE_ABORT (do_abort, written, fd);
+      if ((action & do_backtrace))
+	BEFORE_ABORT (do_abort, written, fd);
 
       /* Kill the application.  */
       abort ();
@@ -182,6 +183,6 @@ __libc_fatal (const char *message)
 {
   /* The loop is added only to keep gcc happy.  */
   while (1)
-    __libc_message (1, "%s", message);
+    __libc_message (do_abort | do_backtrace, "%s", message);
 }
 libc_hidden_def (__libc_fatal)