Commit 7f28dad3 authored by Vasily Gorbik's avatar Vasily Gorbik
Browse files

s390: disable preemption when switching to nodat stack with CALL_ON_STACK 



Make sure preemption is disabled when temporary switching to nodat
stack with CALL_ON_STACK helper, because nodat stack is per cpu.

Reviewed-by: default avatarHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: default avatarVasily Gorbik <gor@linux.ibm.com>
parent c2e06e15

arch/s390/kernel/machine_kexec.c

+2 −0
Original line number Diff line number Diff line
@@ -164,7 +164,9 @@ static bool kdump_csum_valid(struct kimage *image) 
#ifdef CONFIG_CRASH_DUMP

	int rc;



	preempt_disable();

	rc = CALL_ON_STACK(do_start_kdump, S390_lowcore.nodat_stack, 1, image);

	preempt_enable();

	return rc == 0;

#else

	return false;

arch/s390/mm/maccess.c

+9 −3
Original line number Diff line number Diff line
@@ -119,9 +119,15 @@ static unsigned long __no_sanitize_address _memcpy_real(unsigned long dest, 
 */

int memcpy_real(void *dest, void *src, size_t count)

{

	if (S390_lowcore.nodat_stack != 0)

		return CALL_ON_STACK(_memcpy_real, S390_lowcore.nodat_stack,

				     3, dest, src, count);

	int rc;



	if (S390_lowcore.nodat_stack != 0) {

		preempt_disable();

		rc = CALL_ON_STACK(_memcpy_real, S390_lowcore.nodat_stack, 3,

				   dest, src, count);

		preempt_enable();

		return rc;

	}

	/*

	 * This is a really early memcpy_real call, the stacks are

	 * not set up yet. Just call _memcpy_real on the early boot