tst-setcontext10.c: Undef _FORTIFY_SOURCE

When _FORTIFY_SOURCE is defined to 2, ____longjmp_chk is called,
instead of longjmp.  ____longjmp_chk compares the relative stack
values to decide if it is called from a stack frame which called
setjmp.  If not, ____longjmp_chk assumes that an alternate signal
stack is used.  Since comparing the relative stack values isn't
reliable with user context, when there is no signal, ____longjmp_chk
will fail.  Undefine _FORTIFY_SOURCE to avoid ____longjmp_chk in
user context test.

diff --git a/stdlib/tst-setcontext10.c b/stdlib/tst-setcontext10.c
index 2926753..d714563 100644 (file)
--- a/stdlib/tst-setcontext10.c
+++ b/stdlib/tst-setcontext10.c
@@ -16,6 +16,15 @@
    License along with the GNU C Library; if not, see
    <https://www.gnu.org/licenses/>.  */
 
+/* When _FORTIFY_SOURCE is defined to 2, ____longjmp_chk is called,
+   instead of longjmp.  ____longjmp_chk compares the relative stack
+   values to decide if it is called from a stack frame which called
+   setjmp.  If not, ____longjmp_chk assumes that an alternate signal
+   stack is used.  Since comparing the relative stack values isn't
+   reliable with user context, when there is no signal, ____longjmp_chk
+   will fail.  Undefine _FORTIFY_SOURCE to avoid ____longjmp_chk.  */
+#undef _FORTIFY_SOURCE
+
 #include <stdio.h>
 #include <stdlib.h>
 #include <setjmp.h>