powerpc: Fix denormalized exception handler

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The denormalized exception handler (denorm_exception_hv) has a couple
of bugs.  If the CONFIG_PPC_DENORMALISATION option is not selected,
or the HSRR1_DENORM bit is not set in HSRR1, we don't test whether the
interrupt occurred within a KVM guest.  On the other hand, if the
HSRR1_DENORM bit is set and CONFIG_PPC_DENORMALISATION is enabled,
we corrupt the CFAR and PPR.

To correct these problems, this replaces the open-coded version of
EXCEPTION_PROLOG_1 that is there currently, and that is missing the
saving of PPR and CFAR values to the PACA, with an instance of
EXCEPTION_PROLOG_1.  This adds an explicit KVMTEST after testing
whether the exception is one we can handle, and adds code to restore
the CFAR on exit.

Signed-off-by: Paul Mackerras <paulus@samba.org>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

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Paul Mackerras 2013-08-12 16:12:06 +10:00 • committed by Benjamin Herrenschmidt

parent d82fbf305c

commit 630573c1da

1 changed files with 6 additions and 5 deletions

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arch/powerpc/kernel/exceptions-64s.S

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