[PATCH v9 09/13] arm64: BTI: Reset BTYPE when skipping emulated instructions
From: Mark Brown
Date: Wed Mar 11 2020 - 15:33:21 EST
From: Dave Martin <Dave.Martin@xxxxxxx>
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@xxxxxxx>
Signed-off-by: Mark Brown <broonie@xxxxxxxxxx>
---
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 3c07a7074145..52ed261e7739 100644
--- a/arch/arm64/kernel/traps.c
+++ b/arch/arm64/kernel/traps.c
@@ -335,6 +335,8 @@ void arm64_skip_faulting_instruction(struct pt_regs *regs, unsigned long size)
if (compat_user_mode(regs))
advance_itstate(regs);
+ else
+ regs->pstate &= ~PSR_BTYPE_MASK;
}
static LIST_HEAD(undef_hook);
--
2.20.1