From: Mark Rutland <mark.rutland@arm.com>
To: Khaja Hussain Shaik Khaji <khaja.khaji@oss.qualcomm.com>
Cc: catalin.marinas@arm.com, dev.jain@arm.com,
linux-kernel@vger.kernel.org, yang@os.amperecomputing.com,
linux-arm-msm@vger.kernel.org, will@kernel.org,
linux-arm-kernel@lists.infradead.org, mhiramat@kernel.org
Subject: Re: [PATCH v2 2/2] arm64: insn: drop NOP from steppable hint list
Date: Tue, 17 Feb 2026 16:57:08 +0000 [thread overview]
Message-ID: <aZSd5O0gdGM9dUkR@J2N7QTR9R3.cambridge.arm.com> (raw)
In-Reply-To: <20260217133855.3142192-3-khaja.khaji@oss.qualcomm.com>
On Tue, Feb 17, 2026 at 07:08:55PM +0530, Khaja Hussain Shaik Khaji wrote:
> NOP is already handled via instruction emulation and does not require
> single-stepping. Drop it from aarch64_insn_is_steppable_hint().
>
> Signed-off-by: Khaja Hussain Shaik Khaji <khaja.khaji@oss.qualcomm.com>
> ---
> arch/arm64/include/asm/insn.h | 1 -
> 1 file changed, 1 deletion(-)
>
> diff --git a/arch/arm64/include/asm/insn.h b/arch/arm64/include/asm/insn.h
> index e1d30ba99d01..9429f76906e0 100644
> --- a/arch/arm64/include/asm/insn.h
> +++ b/arch/arm64/include/asm/insn.h
> @@ -456,7 +456,6 @@ static __always_inline bool aarch64_insn_is_steppable_hint(u32 insn)
> case AARCH64_INSN_HINT_BTIC:
> case AARCH64_INSN_HINT_BTIJ:
> case AARCH64_INSN_HINT_BTIJC:
> - case AARCH64_INSN_HINT_NOP:
> return true;
> default:
> return false;
The intent is that aarch64_insn_is_steppable_hint() says whether an
instruction is safe to step, not whether it *must* be stepped. I think
we can leave NOP here unless this is causing some functional problem?
Mark.
next prev parent reply other threads:[~2026-02-17 16:57 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-11-06 10:49 [PATCH] arm64: insn: Route BTI to simulate_nop to avoid XOL/SS at function entry Khaja Hussain Shaik Khaji
2025-11-11 10:26 ` Mark Rutland
2025-11-12 12:17 ` Mark Rutland
2026-02-17 13:38 ` [PATCH v2 0/2] arm64: kprobes: fix XOL preemption window Khaja Hussain Shaik Khaji
2026-02-17 13:38 ` [PATCH v2 1/2] arm64: kprobes: disable preemption across XOL single-step Khaja Hussain Shaik Khaji
2026-02-17 16:55 ` Mark Rutland
2026-02-23 16:07 ` Masami Hiramatsu
2026-03-02 10:19 ` Khaja Hussain Shaik Khaji
2026-03-02 10:23 ` Mark Rutland
2026-03-02 10:53 ` [PATCH v3 0/1] kernel: kprobes: fix cur_kprobe corruption during Khaja Hussain Shaik Khaji
2026-03-02 10:53 ` [PATCH v3 1/1] kernel: kprobes: fix cur_kprobe corruption during re-entrant kprobe_busy_begin() calls Khaja Hussain Shaik Khaji
2026-03-02 13:38 ` Mark Rutland
2026-03-02 11:23 ` [PATCH v3 0/1] kernel: kprobes: fix cur_kprobe corruption during Mark Rutland
2026-03-02 12:23 ` [PATCH v3 0/1] kernel: kprobes: fix cur_kprobe corruption during re-entrant kprobe_busy_begin() calls Khaja Hussain Shaik Khaji
2026-03-02 13:43 ` Mark Rutland
2026-02-17 13:38 ` [PATCH v2 2/2] arm64: insn: drop NOP from steppable hint list Khaja Hussain Shaik Khaji
2026-02-17 16:57 ` Mark Rutland [this message]
2026-02-24 8:23 ` Masami Hiramatsu
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