4.20-stable review patch. If anyone has any objections, please let me know.
------------------
From: Martin Schwidefsky <schwidefsky@xxxxxxxxxx>
commit 634692ab7007e8e3fec758ab0b26e65abf7c79e0 upstream.
The patch that added support for the virtually mapped kernel stacks changed
swsusp_arch_suspend to switch to the nodat-stack as the vmap stack is not
available while going in and out of suspend.
Unfortunately the switch to the nodat-stack is incorrect which breaks
suspend to disk.
Cc: stable@xxxxxxxxxxxxxxx # v4.20
Fixes: ce3dc447493f ("s390: add support for virtually mapped kernel stacks")
Signed-off-by: Martin Schwidefsky <schwidefsky@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/s390/kernel/swsusp.S | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
--- a/arch/s390/kernel/swsusp.S
+++ b/arch/s390/kernel/swsusp.S
@@ -30,10 +30,10 @@
.section .text
ENTRY(swsusp_arch_suspend)
lg %r1,__LC_NODAT_STACK
- aghi %r1,-STACK_FRAME_OVERHEAD
stmg %r6,%r15,__SF_GPRS(%r1)
+ aghi %r1,-STACK_FRAME_OVERHEAD
stg %r15,__SF_BACKCHAIN(%r1)
- lgr %r1,%r15
+ lgr %r15,%r1
/* Store FPU registers */
brasl %r14,save_fpu_regs
