From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 5DB0C36EA82; Tue, 17 Feb 2026 16:57:13 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771347434; cv=none; b=AvWo6sTKLzNmme6P4nUOwCK4srwr40Wh1RM03tVbTkhV1ygoq9Y8TqNoRhkGLVHWdPtJSz6fCw0DEaQat0GhrByD2rrPBbmsB/+wcNQA/v6gYDQDqYwYDpGmdwnJhChyp24eGlqyPo6ddSPw75TDayCefPulucFeq/TXihpKuXs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1771347434; c=relaxed/simple; bh=MkrfJhrfMnF73crGr4J6gThPr+9VbYlUypDShbpRoxg=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=SPjUEpEWnXjUfAjU5knIdVAG1NHS56zQN1Tp0jdJCbblwEArzPFng0Yf7DDrqbqJWLrhqjpn/5R5p7wlK8KG4NlplLbOragBZZ5iVJwHFcy71oGfW1ivkyo8FRZY/2jrDXPQQo+8KBbEM8uMm5h2WE1YzoqvrN+LHJOl4R/qfsY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 8B9C91477; Tue, 17 Feb 2026 08:57:06 -0800 (PST) Received: from J2N7QTR9R3.cambridge.arm.com (usa-sjc-imap-foss1.foss.arm.com [10.121.207.14]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 3E3853F62B; Tue, 17 Feb 2026 08:57:11 -0800 (PST) Date: Tue, 17 Feb 2026 16:57:08 +0000 From: Mark Rutland To: Khaja Hussain Shaik Khaji Cc: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, catalin.marinas@arm.com, will@kernel.org, mhiramat@kernel.org, yang@os.amperecomputing.com, dev.jain@arm.com, ada.coupriediaz@arm.com, linux-arm-msm@vger.kernel.org Subject: Re: [PATCH v2 2/2] arm64: insn: drop NOP from steppable hint list Message-ID: References: <20251106104955.2089268-1-khaja.khaji@oss.qualcomm.com> <20260217133855.3142192-1-khaja.khaji@oss.qualcomm.com> <20260217133855.3142192-3-khaja.khaji@oss.qualcomm.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline 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 > --- > 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.