| Message ID | 1229211183-5350-1-git-send-email-galak@kernel.crashing.org (mailing list archive) |
|---|---|
| State | Accepted, archived |
| Commit | e5e774d8833de1a0037be2384efccadf16935675 |
| Headers | show |
On Sat, 2008-12-13 at 17:33 -0600, Kumar Gala wrote: > An example calling sequence which we did see: > > copy_user_highpage -> kmap_atomic -> flush_tlb_page -> _tlbil_va > > We got interrupted after setting up the MAS registers before the > tlbwe and the interrupt handler that caused the interrupt also did > a kmap_atomic (ide code) and thus on returning from the interrupt > the MAS registers no longer contained the proper values. > > Since we dont save/restore MAS registers for normal interrupts we > need to disable interrupts in _tlbil_va to ensure atomicity. > > Signed-off-by: Kumar Gala <galak@kernel.crashing.org> Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> --- Paul, this is a 2.6.28 regression, it should probably go to Linus in case he hasn't released yet :-) Cheers, Ben.
diff --git a/arch/powerpc/kernel/misc_32.S b/arch/powerpc/kernel/misc_32.S index bdc8b0e..d108715 100644 --- a/arch/powerpc/kernel/misc_32.S +++ b/arch/powerpc/kernel/misc_32.S @@ -479,6 +479,8 @@ _GLOBAL(_tlbil_pid) * (no broadcast) */ _GLOBAL(_tlbil_va) + mfmsr r10 + wrteei 0 slwi r4,r4,16 mtspr SPRN_MAS6,r4 /* assume AS=0 for now */ tlbsx 0,r3 @@ -490,6 +492,7 @@ _GLOBAL(_tlbil_va) tlbwe msync isync + wrtee r10 blr #endif /* CONFIG_FSL_BOOKE */
An example calling sequence which we did see: copy_user_highpage -> kmap_atomic -> flush_tlb_page -> _tlbil_va We got interrupted after setting up the MAS registers before the tlbwe and the interrupt handler that caused the interrupt also did a kmap_atomic (ide code) and thus on returning from the interrupt the MAS registers no longer contained the proper values. Since we dont save/restore MAS registers for normal interrupts we need to disable interrupts in _tlbil_va to ensure atomicity. Signed-off-by: Kumar Gala <galak@kernel.crashing.org> --- arch/powerpc/kernel/misc_32.S | 3 +++ 1 files changed, 3 insertions(+), 0 deletions(-)