diff options
| author | Nicholas Piggin <npiggin@gmail.com> | 2016-12-20 04:30:04 +1000 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2017-04-28 21:02:25 +1000 |
| commit | a3d96f70c14773d0928c6a54fd278138f0868572 (patch) | |
| tree | 740c198af62ef423ee257f601616031eee84981b /arch/powerpc/kernel | |
| parent | a4087a4d38981bef3de7dd814493df202919cd2e (diff) | |
powerpc/64s: Fix system reset vs general interrupt reentrancy
The system reset interrupt can occur when MSR_EE=0, and it currently
uses the PACA_EXGEN save area.
Some PACA_EXGEN interrupts have a window where MSR_RI=1 and MSR_EE=0
when the save area is still in use. A system reset interrupt in this
window can lead to undetected corruption when the save area gets
overwritten.
This patch introduces PACA_EXNMI save area for system reset exceptions,
which closes this corruption window. It's also helpful to retain the
EXGEN state for debugging situations, even if not considering the
recoverability aspect.
This patch also moves the PACA_EXMC area down to a less frequently used
part of the paca with the new save area.
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Diffstat (limited to 'arch/powerpc/kernel')
| -rw-r--r-- | arch/powerpc/kernel/asm-offsets.c | 1 | ||||
| -rw-r--r-- | arch/powerpc/kernel/exceptions-64s.S | 9 |
2 files changed, 7 insertions, 3 deletions
diff --git a/arch/powerpc/kernel/asm-offsets.c b/arch/powerpc/kernel/asm-offsets.c index 8e1163426ccb..46732ee70b43 100644 --- a/arch/powerpc/kernel/asm-offsets.c +++ b/arch/powerpc/kernel/asm-offsets.c @@ -220,6 +220,7 @@ int main(void) OFFSET(PACA_EXGEN, paca_struct, exgen); OFFSET(PACA_EXMC, paca_struct, exmc); OFFSET(PACA_EXSLB, paca_struct, exslb); + OFFSET(PACA_EXNMI, paca_struct, exnmi); OFFSET(PACALPPACAPTR, paca_struct, lppaca_ptr); OFFSET(PACA_SLBSHADOWPTR, paca_struct, slb_shadow_ptr); OFFSET(SLBSHADOW_STACKVSID, slb_shadow, save_area[SLB_NUM_BOLTED - 1].vsid); diff --git a/arch/powerpc/kernel/exceptions-64s.S b/arch/powerpc/kernel/exceptions-64s.S index f765531c67b1..3a654b1f24e9 100644 --- a/arch/powerpc/kernel/exceptions-64s.S +++ b/arch/powerpc/kernel/exceptions-64s.S @@ -116,7 +116,7 @@ EXC_VIRT_NONE(0x4000, 0x100) EXC_REAL_BEGIN(system_reset, 0x100, 0x100) SET_SCRATCH0(r13) - EXCEPTION_PROLOG_PSERIES(PACA_EXGEN, system_reset_common, EXC_STD, + EXCEPTION_PROLOG_PSERIES(PACA_EXNMI, system_reset_common, EXC_STD, IDLETEST, 0x100) EXC_REAL_END(system_reset, 0x100, 0x100) @@ -127,7 +127,10 @@ EXC_COMMON_BEGIN(system_reset_idle_common) b pnv_powersave_wakeup #endif -EXC_COMMON(system_reset_common, 0x100, system_reset_exception) +EXC_COMMON_BEGIN(system_reset_common) + EXCEPTION_COMMON(PACA_EXNMI, 0x100, + system_reset, system_reset_exception, + ret_from_except, ADD_NVGPRS;ADD_RECONCILE) #ifdef CONFIG_PPC_PSERIES /* @@ -135,7 +138,7 @@ EXC_COMMON(system_reset_common, 0x100, system_reset_exception) */ TRAMP_REAL_BEGIN(system_reset_fwnmi) SET_SCRATCH0(r13) /* save r13 */ - EXCEPTION_PROLOG_PSERIES(PACA_EXGEN, system_reset_common, EXC_STD, + EXCEPTION_PROLOG_PSERIES(PACA_EXNMI, system_reset_common, EXC_STD, NOTEST, 0x100) #endif /* CONFIG_PPC_PSERIES */ |