From 891f6a726cacbb87e5b06076693ffab53bd378d7 Mon Sep 17 00:00:00 2001 From: Christian Borntraeger Date: Thu, 21 Jun 2018 14:49:38 +0200 Subject: [PATCH] s390: Correct register corruption in critical section cleanup MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit 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 Reported-by: Petr Tesařík Signed-off-by: Christian Borntraeger Reviewed-by: Hendrik Brueckner Signed-off-by: Martin Schwidefsky --- arch/s390/kernel/entry.S | 4 ++-- 1 file 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 .Lcleanup_table: @@ -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 #endif .Lcleanup_system_call: -- 2.11.0