From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id AD9CE1F4265; Tue, 3 Dec 2024 12:48:13 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1733230094; cv=none; b=R3qKChsEeDZlIJi8UdtBimHIwNj3IrESVhWy98SpKmIPlDFuAzw/WXAwQsiis92rGDHvK7Kiyn4pkbp8WlCo9xdjfbrOYsbGJz1NwjO5k9IqSW4m9ffTxg424tyX0a6NBnHcomlyGRCYf0fr4fAP5ykVbXwZCuCn+AEL5pxBaQo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1733230094; c=relaxed/simple; bh=A8QKBxilDmxPa7rkbda6zcbE9W7eNHPT2bdz3YleFLw=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=nwwGfcMUNxLMVvAqCE0gNJz831GzPYO84z40bXl1bSbvwoLlC75NhgRJ77YmNZgElTJkOc8WVgFxuUesZ5StL35QgrlcAFSw/JBiah2pXcKhQJRZU6cJtkDG8mGBy4dQDySaAcUcspBK798JIf0jZfXhCXMcyPfzMVQY0EcKpcw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=YB1/JhVV; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="YB1/JhVV" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 35ACEC4CEDA; Tue, 3 Dec 2024 12:48:12 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1733230093; bh=A8QKBxilDmxPa7rkbda6zcbE9W7eNHPT2bdz3YleFLw=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=YB1/JhVVfVllWqpTIrk7/axmeR9qWo1CHsDZMaaZTOWJ29KPqtjV3kLB4Pk0GoN2V AbbvlHTU1FZ+DHYwFi6AF3Yeu1TKtv9Yew9wF0o6u89WlZgOlzsLREFY46EmLl4PKE gPF3qGGGtg59PCzJPDt1gkn684JMR/mBBVmy2MShSIbi26KebRhM7L9dA3FiXS6KUs SwyBymbe+bDRIlhaoAYRn/ZBN5dHh2KzXQjr2m27ZIVUMpOTk8jlRJMmXw9f8XTI4k 58sA3Wu7c1Pc8ei4ezose9Kdwq05p9VvShFCdrxjTEdh93/RDQeITLthtHW2ol+mUm HN/ENvn45KIsg== From: Mark Brown Date: Tue, 03 Dec 2024 12:45:55 +0000 Subject: [PATCH 3/6] arm64/ptrace: Zero FPMR on streaming mode entry/exit 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="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20241203-arm64-sme-reenable-v1-3-d853479d1b77@kernel.org> References: <20241203-arm64-sme-reenable-v1-0-d853479d1b77@kernel.org> In-Reply-To: <20241203-arm64-sme-reenable-v1-0-d853479d1b77@kernel.org> To: Catalin Marinas , Will Deacon Cc: Mark Rutland , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Mark Brown , stable@vger.kernel.org X-Mailer: b4 0.15-dev-9b746 X-Developer-Signature: v=1; a=openpgp-sha256; l=2536; i=broonie@kernel.org; h=from:subject:message-id; bh=A8QKBxilDmxPa7rkbda6zcbE9W7eNHPT2bdz3YleFLw=; b=owEBbQGS/pANAwAKASTWi3JdVIfQAcsmYgBnTv4CiOSW2bhpgcdgsYNhwD/Bim4F7ucOylhTitF5 bNZ69KSJATMEAAEKAB0WIQSt5miqZ1cYtZ/in+ok1otyXVSH0AUCZ07+AgAKCRAk1otyXVSH0LOrB/ 99y5btc73beTOcl314LKxYh6c8mPHO20HigFHyqQdH86SXdpieb5FJR5m4nRfAnosSZgvstgKONgTz XZqsLN/KGPd4tQ9DKCVEydJ3/qFG/nswfG8vbzrZjvHZJ/R27QaD+TrhV3stJvQ+vb9ExTbYHxLbly a2q+yRIYr7+UZg5twhsndT1luzc4kNgcnc3yyEiqUm/6CQZzYTl3hn7duGakQiQun0A5IFN4fo3+7W /RfIDT448OmJWNI/6atAEtDOSpHazBrW8YbYL2Hn8+vGSQmltJjnGmtktoMOAjED3od8W1fkRBQB9w gfO+/3RX68xQLyTKjlR4djCYJYqWcj X-Developer-Key: i=broonie@kernel.org; a=openpgp; fpr=3F2568AAC26998F9E813A1C5C3F436CA30F5D8EB When FPMR and SME are both present then entering and exiting streaming mode clears FPMR in the same manner as it clears the V/Z and P registers. Since entering and exiting streaming mode via ptrace is expected to have the same effect as doing so via SMSTART/SMSTOP it should clear FPMR too but this was missed when FPMR support was added. Add the required reset of FPMR. Since changing the vector length resets SVCR a SME vector length change implemented via a write to ZA can trigger an exit of streaming mode and we need to check when writing to ZA as well. Fixes: 4035c22ef7d4 ("arm64/ptrace: Expose FPMR via ptrace") Signed-off-by: Mark Brown Cc: stable@vger.kernel.org --- arch/arm64/kernel/ptrace.c | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) diff --git a/arch/arm64/kernel/ptrace.c b/arch/arm64/kernel/ptrace.c index e4437f62a2cda93734052c44b48886db83d75b3e..43a9397d5903ff87b608befdcaed3f9a7e48f976 100644 --- a/arch/arm64/kernel/ptrace.c +++ b/arch/arm64/kernel/ptrace.c @@ -877,6 +877,7 @@ static int sve_set_common(struct task_struct *target, const void *kbuf, const void __user *ubuf, enum vec_type type) { + u64 old_svcr = target->thread.svcr; int ret; struct user_sve_header header; unsigned int vq; @@ -908,8 +909,6 @@ static int sve_set_common(struct task_struct *target, /* Enter/exit streaming mode */ if (system_supports_sme()) { - u64 old_svcr = target->thread.svcr; - switch (type) { case ARM64_VEC_SVE: target->thread.svcr &= ~SVCR_SM_MASK; @@ -1008,6 +1007,10 @@ static int sve_set_common(struct task_struct *target, start, end); out: + /* If we entered or exited streaming mode then reset FPMR */ + if ((target->thread.svcr & SVCR_SM) != (old_svcr & SVCR_SM)) + target->thread.uw.fpmr = 0; + fpsimd_flush_task_state(target); return ret; } @@ -1104,6 +1107,7 @@ static int za_set(struct task_struct *target, unsigned int pos, unsigned int count, const void *kbuf, const void __user *ubuf) { + u64 old_svcr = target->thread.svcr; int ret; struct user_za_header header; unsigned int vq; @@ -1184,6 +1188,10 @@ static int za_set(struct task_struct *target, target->thread.svcr |= SVCR_ZA_MASK; out: + /* If we entered or exited streaming mode then reset FPMR */ + if ((target->thread.svcr & SVCR_SM) != (old_svcr & SVCR_SM)) + target->thread.uw.fpmr = 0; + fpsimd_flush_task_state(target); return ret; } -- 2.39.5