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 970FB1DE4FC; Wed, 6 Nov 2024 11:29:20 +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=1730892562; cv=none; b=KTezThOfn80IJ27Yfr9xsf2EVK9KG5NFmmK4IeyRjkeNPv+26NyIpVEes0qkMx5qn4YUY++yX0zeyGDyvupUVSnxvnttNSQHg8zc/PLk++5JIfO0yFuSWrKbAtMiVl0eWKecLKvMPKkX7IbHofmq4oUYKqoVBIA8bQA3NEbONvU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1730892562; c=relaxed/simple; bh=BCyrLfZAV1dY3c0w3IQl/h7cMA0B8eAPK6Y+udoyLhI=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=InZGlcPtkvn0zuKOiNIUby3+bQDxDj9aIOECm6HB27B8WomO7ldElVCoGX8yQwvjOQgze2jHeP71PCauGKWF4BQi5nk/FBGRCyrt7stIUM3jClnJnNmvBULUrPZZfmSeC1TNypcLpnb7loO2tU4FgDPuCJfWVLaf6pVNbSrtDXM= 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 E256B1063; Wed, 6 Nov 2024 03:29:49 -0800 (PST) Received: from J2N7QTR9R3 (usa-sjc-imap-foss1.foss.arm.com [10.121.207.14]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id B5E933F6A8; Wed, 6 Nov 2024 03:29:18 -0800 (PST) Date: Wed, 6 Nov 2024 11:29:16 +0000 From: Mark Rutland To: Mark Brown Cc: Catalin Marinas , Will Deacon , Shuah Khan , linux-arm-kernel@lists.infradead.org, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 1/6] kselftest/arm64: Correct misleading comments on fp-stress irritators Message-ID: References: <20241023-arm64-fp-stress-irritator-v1-0-a51af298d449@kernel.org> <20241023-arm64-fp-stress-irritator-v1-1-a51af298d449@kernel.org> 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: <20241023-arm64-fp-stress-irritator-v1-1-a51af298d449@kernel.org> On Wed, Oct 23, 2024 at 09:38:29PM +0100, Mark Brown wrote: > The comments in the handlers for the irritator signal in the test threads > for fp-stress suggest that the irritator will corrupt the register state > observed by the main thread but this is not the case, instead the FPSIMD > and SVE irritators (which are the only ones that are implemented) modify > the current register state which is expected to be overwritten on return > from the handler by the saved register state. Update the comment to reflect > what the handler is actually doing. > > Signed-off-by: Mark Brown Acked-by: Mark Rutland Mark. > --- > tools/testing/selftests/arm64/fp/fpsimd-test.S | 3 +-- > tools/testing/selftests/arm64/fp/sve-test.S | 3 +-- > 2 files changed, 2 insertions(+), 4 deletions(-) > > diff --git a/tools/testing/selftests/arm64/fp/fpsimd-test.S b/tools/testing/selftests/arm64/fp/fpsimd-test.S > index 8b960d01ed2e0ef516893b68794078ddf8c01e1f..bdfb7cf2e4ec175fda62c1c2f38c6ebb1a1c48bf 100644 > --- a/tools/testing/selftests/arm64/fp/fpsimd-test.S > +++ b/tools/testing/selftests/arm64/fp/fpsimd-test.S > @@ -134,8 +134,7 @@ function check_vreg > b memcmp > endfunction > > -// Any SVE register modified here can cause corruption in the main > -// thread -- but *only* the registers modified here. > +// Modify live register state, the signal return will undo our changes > function irritator_handler > // Increment the irritation signal count (x23): > ldr x0, [x2, #ucontext_regs + 8 * 23] > diff --git a/tools/testing/selftests/arm64/fp/sve-test.S b/tools/testing/selftests/arm64/fp/sve-test.S > index fff60e2a25addfd4850ef71aa3cf6535ac880ffd..e3c0d585684df29723a49265f3df6d23817498c7 100644 > --- a/tools/testing/selftests/arm64/fp/sve-test.S > +++ b/tools/testing/selftests/arm64/fp/sve-test.S > @@ -291,8 +291,7 @@ function check_ffr > #endif > endfunction > > -// Any SVE register modified here can cause corruption in the main > -// thread -- but *only* the registers modified here. > +// Modify live register state, the signal return will undo our changes > function irritator_handler > // Increment the irritation signal count (x23): > ldr x0, [x2, #ucontext_regs + 8 * 23] > > -- > 2.39.2 >