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Subject[PATCH v4 10/12] arm64: BTI: Reset BTYPE when skipping emulated instructions
Date
From: Dave Martin <Dave.Martin@arm.com>

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>
Signed-off-by: Mark Brown <broonie@kernel.org>
---
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 bf79d8024fbe..9fc05ae500e6 100644
--- a/arch/arm64/kernel/traps.c
+++ b/arch/arm64/kernel/traps.c
@@ -332,6 +332,8 @@ 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);
--
2.20.1
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