File 0001-s390x-Align-child-stack-while-clone.-BZ-27968.patch of Package glibc.22553
From dbdc57dc81437c350c8c8e00a2d40d1749da004e Mon Sep 17 00:00:00 2001
From: Stefan Liebler <stli@linux.ibm.com>
Date: Tue, 8 Jun 2021 15:37:32 +0200
Subject: [PATCH] s390x: Align child stack while clone. [BZ #27968]
Starting with recent commit 92a7d1343991897f77afe01041f3b77712445e47
"x86-64: Align child stack to 16 bytes [BZ #27902]"
the new test misc/tst-misalign-clone has failed on s390x/s390.
This patch is now aligning the stack to a double
word boundary as also done in start.S files.
---
sysdeps/unix/sysv/linux/s390/s390-32/clone.S | 8 +++++---
sysdeps/unix/sysv/linux/s390/s390-64/clone.S | 8 +++++---
2 files changed, 10 insertions(+), 6 deletions(-)
diff --git a/sysdeps/unix/sysv/linux/s390/s390-32/clone.S b/sysdeps/unix/sysv/linux/s390/s390-32/clone.S
index bb968db40b..08145e4156 100644
--- a/sysdeps/unix/sysv/linux/s390/s390-32/clone.S
+++ b/sysdeps/unix/sysv/linux/s390/s390-32/clone.S
@@ -33,11 +33,13 @@
ENTRY(__clone)
st %r6,24(%r15) /* store %r6 to save area */
cfi_offset (%r6, -72)
- lr %r0,%r5 /* move *arg out of the way */
ltr %r1,%r2 /* check fn and move to %r1 */
jz error /* no NULL function pointers */
- ltr %r2,%r3 /* check child_stack and move to %r2 */
- jz error /* no NULL stack pointers */
+ lhi %r0,-8 /* Align the child_stack to a ... */
+ nr %r3,%r0 /* double word boundary and ... */
+ jz error /* avoid NULL stack pointers. */
+ lr %r0,%r5 /* move *arg out of the way */
+ lr %r2,%r3 /* move child_stack to %r2 */
lr %r3,%r4 /* move flags to %r3 */
lr %r4,%r6 /* move parent_tid to %r4 */
l %r5,100(%r15) /* load child_tid from stack */
diff --git a/sysdeps/unix/sysv/linux/s390/s390-64/clone.S b/sysdeps/unix/sysv/linux/s390/s390-64/clone.S
index 9eafff7561..21d485e9e9 100644
--- a/sysdeps/unix/sysv/linux/s390/s390-64/clone.S
+++ b/sysdeps/unix/sysv/linux/s390/s390-64/clone.S
@@ -34,11 +34,13 @@
ENTRY(__clone)
stg %r6,48(%r15) /* store %r6 to save area */
cfi_offset (%r6,-112)
- lgr %r0,%r5 /* move *arg out of the way */
ltgr %r1,%r2 /* check fn and move to %r1 */
jz error /* no NULL function pointers */
- ltgr %r2,%r3 /* check child_stack and move to %r2 */
- jz error /* no NULL stack pointers */
+ lghi %r0,-16 /* Align the child_stack to a ... */
+ ngr %r3,%r0 /* double word boundary and ... */
+ jz error /* avoid NULL stack pointers. */
+ lgr %r0,%r5 /* move *arg out of the way */
+ lgr %r2,%r3 /* move child_stack to %r2 */
lgr %r3,%r4 /* move flags to %r3 */
lgr %r4,%r6 /* move parent_tid to %r4 */
lg %r5,168(%r15) /* load child_tid from stack */
--
2.33.1