Messages in this thread Patch in this message | | | From | Dave Martin <> | Subject | [PATCH v3 11/12] arm64: BTI: Reset BTYPE when skipping emulated instructions | Date | Fri, 18 Oct 2019 18:25:44 +0100 |
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Since normal execution of any non-branch instruction resets the PSTATE BTYPE field to 0, so do the same thing when emulating a trapped instruction.
Branches don't trap directly, so we should never need to assign a non-zero value to BTYPE here.
Signed-off-by: Dave Martin <Dave.Martin@arm.com>
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Changes since v2:
* Drop (u64) case when masking out PSR_BTYPE_MASK in arm64_skip_faulting_instruction().
PSTATE may grow, but we should address this more generally rather than with point hacks in this series. --- arch/arm64/kernel/traps.c | 2 ++ 1 file changed, 2 insertions(+)
diff --git a/arch/arm64/kernel/traps.c b/arch/arm64/kernel/traps.c index 3af2768..5c46a7b 100644 --- a/arch/arm64/kernel/traps.c +++ b/arch/arm64/kernel/traps.c @@ -331,6 +331,8 @@ void arm64_skip_faulting_instruction(struct pt_regs *regs, unsigned long size) if (regs->pstate & PSR_MODE32_BIT) advance_itstate(regs); + else + regs->pstate &= ~PSR_BTYPE_MASK; } static LIST_HEAD(undef_hook); -- 2.1.4
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