Messages in this thread Patch in this message | | | Subject | [PATCH v2 1/4] kprobes/powerpc: Do not disable External interrupts during single step | From | "Suzuki K. Poulose" <> | Date | Mon, 03 Dec 2012 20:37:42 +0530 |
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From: Suzuki K. Poulose <suzuki@in.ibm.com>
External/Decrement exceptions have lower priority than the Debug Exception. So, we don't have to disable the External interrupts before a single step. However, on BookE, Critical Input Exception(CE) has higher priority than a Debug Exception. Hence we mask them.
Signed-off-by: Suzuki K. Poulose <suzuki@in.ibm.com> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Ananth N Mavinakaynahalli <ananth@in.ibm.com> Cc: Kumar Gala <galak@kernel.crashing.org> Cc: linuxppc-dev@ozlabs.org --- arch/powerpc/kernel/kprobes.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-)
diff --git a/arch/powerpc/kernel/kprobes.c b/arch/powerpc/kernel/kprobes.c index e88c643..4901b34 100644 --- a/arch/powerpc/kernel/kprobes.c +++ b/arch/powerpc/kernel/kprobes.c @@ -104,13 +104,13 @@ void __kprobes arch_remove_kprobe(struct kprobe *p) static void __kprobes prepare_singlestep(struct kprobe *p, struct pt_regs *regs) { - /* We turn off async exceptions to ensure that the single step will - * be for the instruction we have the kprobe on, if we dont its - * possible we'd get the single step reported for an exception handler - * like Decrementer or External Interrupt */ - regs->msr &= ~MSR_EE; regs->msr |= MSR_SINGLESTEP; #ifdef CONFIG_PPC_ADV_DEBUG_REGS + /* + * We turn off Critical Input Exception(CE) to ensure that the single + * step will be for the instruction we have the probe on; if we don't, + * it is possible we'd get the single step reported for CE. + */ regs->msr &= ~MSR_CE; mtspr(SPRN_DBCR0, mfspr(SPRN_DBCR0) | DBCR0_IC | DBCR0_IDM); #ifdef CONFIG_PPC_47x
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