s390x: Align child stack while clone. [BZ #27968]
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Commit Message
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(-)
Comments
On 08/06/2021 15:37, Stefan Liebler wrote:
> 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 */
>
I've just committed the s390x specific patch and closed the bugzilla.
Bye,
Stefan
@@ -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 */
@@ -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 */