From: H.J. Lu <hjl.tools@gmail.com>
Date: Tue, 19 Dec 2023 17:55:25 +0000 (-0800)
Subject: tst-setcontext10.c: Undef _FORTIFY_SOURCE
X-Git-Tag: glibc-2.39~179
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=46432be2f1d4de962b51ca6b9f80fc37744be9f7;p=thirdparty%2Fglibc.git

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 2926753cb13..d714563742b 100644
--- 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>