Commit 7a04d491 authored by Alexander Gordeev's avatar Alexander Gordeev Committed by Vasily Gorbik
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s390/kexec: turn DAT mode off immediately before purgatory 



The kernel code is not guaranteed DAT-off mode safe.
Turn the DAT mode off immediately before entering the
purgatory.

Further, to avoid subtle side effects reset the system
immediately before turning DAT mode off while making
all necessary preparations in advance.

Signed-off-by: default avatarAlexander Gordeev <agordeev@linux.ibm.com>
Reviewed-by: default avatarHeiko Carstens <hca@linux.ibm.com>
Signed-off-by: default avatarHeiko Carstens <hca@linux.ibm.com>
Signed-off-by: default avatarVasily Gorbik <gor@linux.ibm.com>
parent 1a33aee1

arch/s390/kernel/machine_kexec.c

+3 −4
Original line number Diff line number Diff line
@@ -254,14 +254,13 @@ static void __do_machine_kexec(void *data) 
	relocate_kernel_t data_mover;

	struct kimage *image = data;



	s390_reset_system();

	data_mover = (relocate_kernel_t) page_to_phys(image->control_code_page);



	__arch_local_irq_stnsm(0xfb); /* disable DAT - avoid no-execute */

	/* Call the moving routine */

	diag308_subcode = DIAG308_CLEAR_RESET;

	if (sclp.has_iplcc)

		diag308_subcode |= DIAG308_FLAG_EI;

	s390_reset_system();



	__arch_local_irq_stnsm(0xfb); /* disable DAT - avoid no-execute */

	(*data_mover)(&image->head, image->start, diag308_subcode);



	/* Die if kexec returns */