diff options
Diffstat (limited to 'arch/powerpc/kernel/exceptions-64s.S')
| -rw-r--r-- | arch/powerpc/kernel/exceptions-64s.S | 14 |
1 files changed, 11 insertions, 3 deletions
diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S index 0fc8bad878b2..446e54c3f71e 100644 --- a/arch/powerpc/kernel/exceptions-64s.S +++ b/arch/powerpc/kernel/exceptions-64s.S @@ -3072,10 +3072,18 @@ do_hash_page: ori r0,r0,DSISR_BAD_FAULT_64S@l and. r0,r5,r0 /* weird error? */ bne- handle_page_fault /* if not, try to insert a HPTE */ + + /* + * If we are in an "NMI" (e.g., an interrupt when soft-disabled), then + * don't call hash_page, just fail the fault. This is required to + * prevent re-entrancy problems in the hash code, namely perf + * interrupts hitting while something holds H_PAGE_BUSY, and taking a + * hash fault. See the comment in hash_preload(). + */ ld r11, PACA_THREAD_INFO(r13) - lwz r0,TI_PREEMPT(r11) /* If we're in an "NMI" */ - andis. r0,r0,NMI_MASK@h /* (i.e. an irq when soft-disabled) */ - bne 77f /* then don't call hash_page now */ + lwz r0,TI_PREEMPT(r11) + andis. r0,r0,NMI_MASK@h + bne 77f /* * r3 contains the trap number |