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Commit 70e28aa0 authored by Heiko Carstens's avatar Heiko Carstens Committed by Martin Schwidefsky
Browse files

s390/nmi: fix order of register validation 



When validating register contents first validate control registers
since these control the availability of features later being
validated.
For example the control register 0 should be validated first, before
the additional floating point (AFP) registers are validated, since
control register 0 contains the AFP-register control bit.

Signed-off-by: default avatarHeiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: default avatarMartin Schwidefsky <schwidefsky@de.ibm.com>
parent 77606708

arch/s390/kernel/nmi.c

+12 −12
Original line number Diff line number Diff line
@@ -116,6 +116,18 @@ static int notrace s390_validate_registers(union mci mci, int umode) 
			s390_handle_damage();

		kill_task = 1;

	}

	/* Validate control registers */

	if (!mci.cr) {

		/*

		 * Control registers have unknown contents.

		 * Can't recover and therefore stopping machine.

		 */

		s390_handle_damage();

	} else {

		asm volatile(

			"	lctlg	0,15,0(%0)"

			: : "a" (&S390_lowcore.cregs_save_area) : "memory");

	}

	if (!mci.fp) {

		/*

		 * Floating point registers can't be restored. If the
@@ -208,18 +220,6 @@ static int notrace s390_validate_registers(union mci mci, int umode) 
		 */

		kill_task = 1;

	}

	/* Validate control registers */

	if (!mci.cr) {

		/*

		 * Control registers have unknown contents.

		 * Can't recover and therefore stopping machine.

		 */

		s390_handle_damage();

	} else {

		asm volatile(

			"	lctlg	0,15,0(%0)"

			: : "a" (&S390_lowcore.cregs_save_area) : "memory");

	}

	/*

	 * We don't even try to validate the TOD register, since we simply

	 * can't write something sensible into that register.