Commit 03c9c8fa authored Sep 14, 2020 by Amit Daniel Kachhap Committed by Will Deacon Sep 14, 2020

arm64: kprobe: clarify the comment of steppable hint instructions



The existing comment about steppable hint instruction is not complete
and only describes NOP instructions as steppable. As the function
aarch64_insn_is_steppable_hint allows all white-listed instruction
to be probed so the comment is updated to reflect this.

Signed-off-by: Amit Daniel Kachhap <amit.kachhap@arm.com>
Reviewed-by: Dave Martin <dave.martin@arm.com>
Link: https://lore.kernel.org/r/20200914083656.21428-7-amit.kachhap@arm.com


Signed-off-by: Will Deacon <will@kernel.org>

parent 6560edca

arch/arm64/kernel/probes/decode-insn.c

+4 −2

Original line number	Diff line number	Diff line
		@@ -43,8 +43,10 @@ static bool __kprobes aarch64_insn_is_steppable(u32 insn)
		!= AARCH64_INSN_SPCLREG_DAIF;

		/*
		* The HINT instruction is is problematic when single-stepping,
		* except for the NOP case.
		* The HINT instruction is steppable only if it is in whitelist
		* and the rest of other such instructions are blocked for
		* single stepping as they may cause exception or other
		* unintended behaviour.
		*/
		if (aarch64_insn_is_hint(insn))
		return aarch64_insn_is_steppable_hint(insn);

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