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| author | Nicholas Piggin <npiggin@gmail.com> | 2016-12-20 04:30:06 +1000 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2017-04-28 21:02:25 +1000 |
| commit | b1ee8a3de5790777f325416ad97340428d8ae25f (patch) | |
| tree | 7fb570821268ff0eab738759eb345b85bc7df179 /arch/powerpc/include | |
| parent | c4f3b52ce7b16824befb16ab3d045c891b08b7db (diff) | |
| download | linux-stable-b1ee8a3de5790777f325416ad97340428d8ae25f.tar.gz linux-stable-b1ee8a3de5790777f325416ad97340428d8ae25f.tar.bz2 linux-stable-b1ee8a3de5790777f325416ad97340428d8ae25f.zip | |
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/include')
| -rw-r--r-- | arch/powerpc/include/asm/exception-64s.h | 13 | ||||
| -rw-r--r-- | arch/powerpc/include/asm/paca.h | 3 |
2 files changed, 15 insertions, 1 deletions
diff --git a/arch/powerpc/include/asm/exception-64s.h b/arch/powerpc/include/asm/exception-64s.h index 59134ebd7d49..38c5c0b33af9 100644 --- a/arch/powerpc/include/asm/exception-64s.h +++ b/arch/powerpc/include/asm/exception-64s.h @@ -563,6 +563,19 @@ END_FTR_SECTION_IFSET(CPU_FTR_CTRL) bl hdlr; \ b ret +/* + * Exception where stack is already set in r1, r1 is saved in r10, and it + * continues rather than returns. + */ +#define EXCEPTION_COMMON_NORET_STACK(area, trap, label, hdlr, additions) \ + EXCEPTION_PROLOG_COMMON_1(); \ + EXCEPTION_PROLOG_COMMON_2(area); \ + EXCEPTION_PROLOG_COMMON_3(trap); \ + /* Volatile regs are potentially clobbered here */ \ + additions; \ + addi r3,r1,STACK_FRAME_OVERHEAD; \ + bl hdlr + #define STD_EXCEPTION_COMMON(trap, label, hdlr) \ EXCEPTION_COMMON(PACA_EXGEN, trap, label, hdlr, \ ret_from_except, ADD_NVGPRS;ADD_RECONCILE) diff --git a/arch/powerpc/include/asm/paca.h b/arch/powerpc/include/asm/paca.h index b1197c1affac..1c09f8fe2ee8 100644 --- a/arch/powerpc/include/asm/paca.h +++ b/arch/powerpc/include/asm/paca.h @@ -185,7 +185,8 @@ struct paca_struct { u64 exmc[13]; /* used for machine checks */ #endif #ifdef CONFIG_PPC_BOOK3S_64 - /* Exclusive emergency stack pointer for machine check exception. */ + /* Exclusive stacks for system reset and machine check exception. */ + void *nmi_emergency_sp; void *mc_emergency_sp; u16 in_nmi; /* In nmi handler */ |