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s390/nmi: fix order of register validation

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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: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
This commit is contained in:
Heiko Carstens 2017-02-21 10:51:55 +01:00 committed by Martin Schwidefsky
parent 776067080c
commit 70e28aa0bb
1 changed files with 12 additions and 12 deletions
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24
arch/s390/kernel/nmi.c
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@ -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.