From b3dcf3de8e4d71d79235fc67b6c5def6506c27f8 Mon Sep 17 00:00:00 2001 From: Heiko Carstens Date: Thu, 29 Oct 2009 15:04:14 +0100 Subject: [PATCH] [S390] smp: fix sigp sense handling sigp sense only returns the status of a cpu if it is non zero. If the status of the sensed cpu is all zeros condition code 0 (accpeted) is set and no status bits are returned. The current code however assumes that a status was returned and tests bits in it. This means uninitalized data is accessed with random results. Worst case is that the code that checks if cpu is offline on cpu hotplug assumes that the target cpu is offline while it is still running. This leads potentially to memory corruption since resources that are still needed by the target cpu will be freed and could be resused while still in use. Signed-off-by: Heiko Carstens Signed-off-by: Martin Schwidefsky --- arch/s390/kernel/smp.c | 1 - arch/s390/kernel/swsusp_asm64.S | 1 + 2 files changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/s390/kernel/smp.c b/arch/s390/kernel/smp.c index c99c45b848e3..93e52039321b 100644 --- a/arch/s390/kernel/smp.c +++ b/arch/s390/kernel/smp.c @@ -76,7 +76,6 @@ static int cpu_stopped(int cpu) __u32 status; switch (signal_processor_ps(&status, 0, cpu, sigp_sense)) { - case sigp_order_code_accepted: case sigp_status_stored: /* Check for stopped and check stop state */ if (status & 0x50) diff --git a/arch/s390/kernel/swsusp_asm64.S b/arch/s390/kernel/swsusp_asm64.S index 0f4ef3b856d9..0c26cc1898ec 100644 --- a/arch/s390/kernel/swsusp_asm64.S +++ b/arch/s390/kernel/swsusp_asm64.S @@ -207,6 +207,7 @@ restart_suspend: llgh %r2,0(%r1) 7: sigp %r9,%r2,__SIGP_SENSE /* Wait for resume CPU */ + brc 8,7b /* accepted, status 0, still running */ brc 2,7b /* busy, try again */ tmll %r9,0x40 /* Test if resume CPU is stopped */ jz 7b -- 2.20.1