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authorNicholas Piggin <npiggin@gmail.com>2016-12-20 04:30:06 +1000
committerMichael Ellerman <mpe@ellerman.id.au>2017-04-28 21:02:25 +1000
commitb1ee8a3de5790777f325416ad97340428d8ae25f (patch)
tree7fb570821268ff0eab738759eb345b85bc7df179 /arch/powerpc/kernel/exceptions-64s.S
parentc4f3b52ce7b16824befb16ab3d045c891b08b7db (diff)
powerpc/64s: Dedicated system reset interrupt stack
The system reset interrupt is used for crash/debug situations, so it is desirable to have as little impact on the normal state of the system as possible. Currently it uses the current kernel stack to process the exception. This stores into the stack which may be involved with the crash. The stack pointer may be corrupted, or it may have overflowed. Avoid or minimise these problems by creating a dedicated NMI stack for the system reset interrupt to use. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'arch/powerpc/kernel/exceptions-64s.S')
-rw-r--r--arch/powerpc/kernel/exceptions-64s.S8
1 files changed, 5 insertions, 3 deletions
diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S
index 4be62568fbc2..3840a7700285 100644
--- a/arch/powerpc/kernel/exceptions-64s.S
+++ b/arch/powerpc/kernel/exceptions-64s.S
@@ -144,10 +144,12 @@ EXC_COMMON_BEGIN(system_reset_common)
li r10,MSR_RI
mtmsrd r10,1
- EXCEPTION_COMMON(PACA_EXNMI, 0x100,
- system_reset, system_reset_exception, 1f,
+ mr r10,r1
+ ld r1,PACA_NMI_EMERG_SP(r13)
+ subi r1,r1,INT_FRAME_SIZE
+ EXCEPTION_COMMON_NORET_STACK(PACA_EXNMI, 0x100,
+ system_reset, system_reset_exception,
ADD_NVGPRS;ADD_RECONCILE)
-1: /* EXCEPTION_COMMON continues here */
/*
* The stack is no longer in use, decrement in_nmi.