From patchwork Mon Sep 16 11:11:50 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Felix Moessbauer X-Patchwork-Id: 13805302 Received: from mta-65-226.siemens.flowmailer.net (mta-65-226.siemens.flowmailer.net [185.136.65.226]) (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 A03F01547E8 for ; Mon, 16 Sep 2024 11:11:59 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.136.65.226 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1726485126; cv=none; b=FNa+g0VS7mYwKHekRKCzmgVHaWdPqjEkaIwWuKL3Ynarhx/jT3G24pep1pHHiKG0480yo7grYVDctYGn9lueXjMp+on0/zshfUidMHo3lQnqO4ySK81NoN4RL6VzfDcKTsZS7CSIpFZpmDUrIq4ZbkR5/uyGhmAqSZTtPH23J0M= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1726485126; c=relaxed/simple; bh=WJW8cWljL5SXL9NmSJQZs7RIFxzYv7xtsUltQ4PLqgw=; h=From:To:Cc:Subject:Date:Message-Id:MIME-Version; b=to/85di3KmH4MpwLqQK1hIiBEga8ou8djk6fTAuSTJKWR3SBGK3RgYRZOrDKUdCM+alIy6AJyk3mk0Q97u6v/dYara41QmeDB8Xdj/x5u002HCSAnvI01AYnK5ZJqzGujf18/wsVV45BtdYgXFVvvulxMumRNqW2ho9AUVJxtGc= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=siemens.com; spf=pass smtp.mailfrom=rts-flowmailer.siemens.com; dkim=pass (2048-bit key) header.d=siemens.com header.i=felix.moessbauer@siemens.com header.b=Rwmv12XB; arc=none smtp.client-ip=185.136.65.226 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=siemens.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=rts-flowmailer.siemens.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=siemens.com header.i=felix.moessbauer@siemens.com header.b="Rwmv12XB" Received: by mta-65-226.siemens.flowmailer.net with ESMTPSA id 202409161111566c59251840fe503267 for ; Mon, 16 Sep 2024 13:11:56 +0200 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; s=fm2; d=siemens.com; i=felix.moessbauer@siemens.com; h=Date:From:Subject:To:Message-ID:MIME-Version:Content-Type:Content-Transfer-Encoding:Cc; bh=GSkjVtv5de9VGr/iaxLd2IImKJowVOPc3pN/8Mu1drg=; b=Rwmv12XByRQYZ+3owmWNe20BPLtVH4E2xzs6zlogbdTxL8Z1X9coRBTaaOjZXSc7mfb8iI mpBLNDAE9k80WDuvrf84PsMMqKDU4WJE0h7LOMKTVaY+FmmAF7KWK6B7EFG3CxokGTdu0R1q SGLu+gjpTLJlkj+UbyVjYigGgpNFBoBvRnb/f9pTZtPzmtvKqxMn/y7if/B+KmWAt7tMpBOR CrHrvfBELrw8Ei6Nhp5mebUjWWw4m7kyDEQAI8Qs84NahRk6RhSe9bC2yiHMS8OR5cjLo/or fawZeEZaO8wcMXqOHT6oLjCC20Ze44VhrWqJTxuLoKrVkK4yaA916A4Q==; From: Felix Moessbauer To: Jens Axboe Cc: io-uring , linux-kernel@vger.kernel.org, Felix Moessbauer Subject: [PATCH v3 1/1] io_uring/sqpoll: do not put cpumask on stack Date: Mon, 16 Sep 2024 13:11:50 +0200 Message-Id: <20240916111150.1266191-1-felix.moessbauer@siemens.com> Precedence: bulk X-Mailing-List: io-uring@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Flowmailer-Platform: Siemens Feedback-ID: 519:519-1321639:519-21489:flowmailer Putting the cpumask on the stack is deprecated for a long time (since 2d3854a37e8), as these can be big. Given that, change the on-stack allocation of allowed_mask to be dynamically allocated. Fixes: f011c9cf04c0 ("io_uring/sqpoll: do not allow pinning outside of cpuset") Signed-off-by: Felix Moessbauer --- Changes since v2: - reworded commit message - make error checking consisten with pattern used in kernel @Jens: Thanks for guiding me and helping me to get this right. Much appreciated. Changes since v1: - don't leak mask in case CPU is not online or too big Best regards, Felix io_uring/sqpoll.c | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-) diff --git a/io_uring/sqpoll.c b/io_uring/sqpoll.c index 7adfcf6818ff..7c79685baeb1 100644 --- a/io_uring/sqpoll.c +++ b/io_uring/sqpoll.c @@ -461,15 +461,22 @@ __cold int io_sq_offload_create(struct io_ring_ctx *ctx, return 0; if (p->flags & IORING_SETUP_SQ_AFF) { - struct cpumask allowed_mask; + cpumask_var_t allowed_mask; int cpu = p->sq_thread_cpu; ret = -EINVAL; if (cpu >= nr_cpu_ids || !cpu_online(cpu)) goto err_sqpoll; - cpuset_cpus_allowed(current, &allowed_mask); - if (!cpumask_test_cpu(cpu, &allowed_mask)) + ret = -ENOMEM; + if (!alloc_cpumask_var(&allowed_mask, GFP_KERNEL)) goto err_sqpoll; + ret = -EINVAL; + cpuset_cpus_allowed(current, allowed_mask); + if (!cpumask_test_cpu(cpu, allowed_mask)) { + free_cpumask_var(allowed_mask); + goto err_sqpoll; + } + free_cpumask_var(allowed_mask); sqd->sq_cpu = cpu; } else { sqd->sq_cpu = -1;