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| author | Christian Borntraeger <borntraeger@de.ibm.com> | 2018-04-27 07:36:51 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-04-29 11:31:59 +0200 |
| commit | 7634817fc5fad945d67c578f04c731ce25dc86bc (patch) | |
| tree | bd52f90b04559dcf831caf171820f1ed016fbb77 /ipc/mq_sysctl.c | |
| parent | 7ae60d00c31e5db697a1518ce94749a0852c1d0c (diff) | |
s390/entry.S: fix spurious zeroing of r0
[ Upstream commit d3f468963cd6fd6d2aa5e26aed8b24232096d0e1 ]
when a system call is interrupted we might call the critical section
cleanup handler that re-does some of the operations. When we are between
.Lsysc_vtime and .Lsysc_do_svc we might also redo the saving of the
problem state registers r0-r7:
.Lcleanup_system_call:
[...]
0: # update accounting time stamp
mvc __LC_LAST_UPDATE_TIMER(8),__LC_SYNC_ENTER_TIMER
# set up saved register r11
lg %r15,__LC_KERNEL_STACK
la %r9,STACK_FRAME_OVERHEAD(%r15)
stg %r9,24(%r11) # r11 pt_regs pointer
# fill pt_regs
mvc __PT_R8(64,%r9),__LC_SAVE_AREA_SYNC
---> stmg %r0,%r7,__PT_R0(%r9)
The problem is now, that we might have already zeroed out r0.
The fix is to move the zeroing of r0 after sysc_do_svc.
Reported-by: Farhan Ali <alifm@linux.vnet.ibm.com>
Fixes: 7041d28115e91 ("s390: scrub registers on kernel entry and KVM exit")
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'ipc/mq_sysctl.c')
0 files changed, 0 insertions, 0 deletions