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authorChristian Borntraeger <borntraeger@de.ibm.com>2018-06-21 14:49:38 +0200
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2018-07-11 16:31:25 +0200
commit3d590170fb5c71cb29db38ac03eeb9ef03c4e362 (patch)
parent04dbce2f5d77eba47369ccd349dae55f9be7f598 (diff)
s390: Correct register corruption in critical section cleanup
commit 891f6a726cacbb87e5b06076693ffab53bd378d7 upstream. In the critical section cleanup we must not mess with r1. For march=z9 or older, larl + ex (instead of exrl) are used with r1 as a temporary register. This can clobber r1 in several interrupt handlers. Fix this by using r11 as a temp register. r11 is being saved by all callers of cleanup_critical. Fixes: 6dd85fbb87 ("s390: move expoline assembler macros to a header") Cc: stable@vger.kernel.org #v4.16 Reported-by: Oliver Kurz <okurz@suse.com> Reported-by: Petr Tesařík <ptesarik@suse.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Reviewed-by: Hendrik Brueckner <brueckner@linux.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
1 files changed, 2 insertions, 2 deletions
diff --git a/arch/s390/kernel/entry.S b/arch/s390/kernel/entry.S
index f03402efab4b..3891805bfcdd 100644
--- a/arch/s390/kernel/entry.S
+++ b/arch/s390/kernel/entry.S
@@ -1265,7 +1265,7 @@ cleanup_critical:
jl 0f
clg %r9,BASED(.Lcleanup_table+104) # .Lload_fpu_regs_end
jl .Lcleanup_load_fpu_regs
-0: BR_EX %r14
+0: BR_EX %r14,%r11
.align 8
@@ -1301,7 +1301,7 @@ cleanup_critical:
ni __SIE_PROG0C+3(%r9),0xfe # no longer in SIE
lctlg %c1,%c1,__LC_USER_ASCE # load primary asce
larl %r9,sie_exit # skip forward to sie_exit
- BR_EX %r14
+ BR_EX %r14,%r11