From 2e43d6db2bb2ca841857725d94aa33a16ee681b0 Mon Sep 17 00:00:00 2001 From: Heiko Carstens Date: Tue, 25 Feb 2025 10:53:10 +0100 Subject: [PATCH] s390/traps: Fix test_monitor_call() inline assembly commit 5623bc23a1cb9f9a9470fa73b3a20321dc4c4870 upstream. The test_monitor_call() inline assembly uses the xgr instruction, which also modifies the condition code, to clear a register. However the clobber list of the inline assembly does not specify that the condition code is modified, which may lead to incorrect code generation. Use the lhi instruction instead to clear the register without that the condition code is modified. Furthermore this limits clearing to the lower 32 bits of val, since its type is int. Fixes: 17248ea03674 ("s390: fix __EMIT_BUG() macro") Cc: stable@vger.kernel.org Reviewed-by: Juergen Christ Signed-off-by: Heiko Carstens Signed-off-by: Vasily Gorbik Signed-off-by: Greg Kroah-Hartman --- arch/s390/kernel/traps.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/arch/s390/kernel/traps.c b/arch/s390/kernel/traps.c index 16934fa19069b..c9dcd47cf7427 100644 --- a/arch/s390/kernel/traps.c +++ b/arch/s390/kernel/traps.c @@ -276,10 +276,10 @@ static void __init test_monitor_call(void) return; asm volatile( " mc 0,0\n" - "0: xgr %0,%0\n" + "0: lhi %[val],0\n" "1:\n" - EX_TABLE(0b,1b) - : "+d" (val)); + EX_TABLE(0b, 1b) + : [val] "+d" (val)); if (!val) panic("Monitor call doesn't work!\n"); } -- 2.47.3