From 93c5029fb87bace3882fc602dab1cc06a8aac6c7 Mon Sep 17 00:00:00 2001 From: Heiko Carstens Date: Tue, 2 Feb 2021 16:45:37 +0100 Subject: [PATCH] s390/vtime: fix inline assembly clobber list commit b29c5093820d333eef22f58cd04ec0d089059c39 upstream. The stck/stckf instruction used within the inline assembly within do_account_vtime() changes the condition code. This is not reflected with the clobber list, and therefore might result in incorrect code generation. It seems unlikely that the compiler could generate incorrect code considering the surrounding C code, but it must still be fixed. Cc: Reviewed-by: Christian Borntraeger Signed-off-by: Heiko Carstens Signed-off-by: Vasily Gorbik Signed-off-by: Greg Kroah-Hartman --- arch/s390/kernel/vtime.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/arch/s390/kernel/vtime.c b/arch/s390/kernel/vtime.c index 8df10d3c8f6c..7b3af2d6b9ba 100644 --- a/arch/s390/kernel/vtime.c +++ b/arch/s390/kernel/vtime.c @@ -136,7 +136,8 @@ static int do_account_vtime(struct task_struct *tsk) " stck %1" /* Store current tod clock value */ #endif : "=Q" (S390_lowcore.last_update_timer), - "=Q" (S390_lowcore.last_update_clock)); + "=Q" (S390_lowcore.last_update_clock) + : : "cc"); clock = S390_lowcore.last_update_clock - clock; timer -= S390_lowcore.last_update_timer;