From patchwork Fri Mar 29 10:56:09 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Dawei Li X-Patchwork-Id: 13610548 X-Patchwork-Delegate: kuba@kernel.org Received: from smtpbguseast3.qq.com (smtpbguseast3.qq.com [54.243.244.52]) (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 5E4356A8AD; Fri, 29 Mar 2024 10:59:38 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=54.243.244.52 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711709983; cv=none; b=QjapkStGAf2FAtJnjoh7G41TJlUX9x4uIjKhYuLXbVMcGVCqXA2E3ftIH5McHgk5n7wMLUQfGZnKAlG8kh/PsvkY3ED46buUF0euIjs0YKn9zJ2uIeUn+CXVXbKUOfRWnZojDiOYRIwmoPO6rCGAV7PIZjnYehEn1YSQjhwe1y4= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711709983; c=relaxed/simple; bh=BGdVHyXu2nvr+uV8Gq6vq1qthRDesSy50eK+N7uOi2c=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=jGbDGl5Hj0peVRLcdC0ZXvFd9kEW57ttwXvpDB8BkGj5zFdzciD7zL9NIGPN84nEZS7M/bLOLH4Lo/5cBZxICsnB5c5ct50w9GL9LrSSVTCFP0BHyDmIhB9PUyLqnj8HUX+d3urCzM4IKw5tOAfgeb4T6v0Ruzk8y99h/pl4T64= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=shingroup.cn; spf=pass smtp.mailfrom=shingroup.cn; arc=none smtp.client-ip=54.243.244.52 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=shingroup.cn Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=shingroup.cn X-QQ-mid: bizesmtp82t1711709843tv80s7ov X-QQ-Originating-IP: 71LQnl3NJNsvgOKyfpSvsNrOkPFMxIaohKLax+fnpYk= Received: from localhost ( [112.0.147.175]) by bizesmtp.qq.com (ESMTP) with id ; Fri, 29 Mar 2024 18:57:21 +0800 (CST) X-QQ-SSF: 01400000000000704000000A0000000 X-QQ-FEAT: 3M0okmaRx3i4lw8jCv5pReqk8XBDZo4W2Lqox8v053W7I2EUN6+uz7amykeXY UGZSGgJiwCVnbILlJeIBx1IXvUentjK22EK6gxsv37dyLssoRUBFH2RJWuDFQY9XyKeux0x UFxv+MynwpUjZ6Aw/i78cnflRKmEh2TnySUC9C0m6y69i5LVTSZ3UF40Rk10mpqdsB2qdwH 3rVww06rDMc5xTqH+llDnXZ2yYgHlBUY3zw6PCNuVQHHIot+AbntyodfvCHjMOvxrnvkQfE bz+WS+INwVRfOTOONWmPMQWkqCbMtaPGXTn4GTd2K4W9y64FtzyAzbB1Ii6rOKbXHDmpIXK c2+2sdCJORS2jNEAs1llYOElRKG3J1SfYVgAdadpbkNwJ91qwMBY0gV70ZhPSoQFwWHkOdr bD7DvGsT4JI= X-QQ-GoodBg: 2 X-BIZMAIL-ID: 8489316982251753822 From: Dawei Li To: davem@davemloft.net, edumazet@google.com, kuba@kernel.org, pabeni@redhat.com, ioana.ciornei@nxp.com, wintera@linux.ibm.com, twinkler@linux.ibm.com Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, linux-s390@vger.kernel.org, Dawei Li Subject: [PATCH net-next 1/2] net/iucv: Avoid explicit cpumask var allocation on stack Date: Fri, 29 Mar 2024 18:56:09 +0800 Message-Id: <20240329105610.922675-2-dawei.li@shingroup.cn> X-Mailer: git-send-email 2.27.0 In-Reply-To: <20240329105610.922675-1-dawei.li@shingroup.cn> References: <20240329105610.922675-1-dawei.li@shingroup.cn> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-QQ-SENDSIZE: 520 Feedback-ID: bizesmtp:shingroup.cn:qybglogicsvrgz:qybglogicsvrgz5a-1 X-Patchwork-Delegate: kuba@kernel.org For CONFIG_CPUMASK_OFFSTACK=y kernel, explicit allocation of cpumask variable on stack is not recommended since it can cause potential stack overflow. Instead, kernel code should always use *cpumask_var API(s) to allocate cpumask var in config-neutral way, leaving allocation strategy to CONFIG_CPUMASK_OFFSTACK. Use *cpumask_var API(s) to address it. Signed-off-by: Dawei Li --- net/iucv/iucv.c | 37 ++++++++++++++++++++++++++----------- 1 file changed, 26 insertions(+), 11 deletions(-) diff --git a/net/iucv/iucv.c b/net/iucv/iucv.c index a4ab615ca3e3..b51f46ec32f9 100644 --- a/net/iucv/iucv.c +++ b/net/iucv/iucv.c @@ -520,14 +520,19 @@ static void iucv_setmask_mp(void) */ static void iucv_setmask_up(void) { - cpumask_t cpumask; + cpumask_var_t cpumask; int cpu; + if (!alloc_cpumask_var(&cpumask, GFP_KERNEL)) + return; + /* Disable all cpu but the first in cpu_irq_cpumask. */ - cpumask_copy(&cpumask, &iucv_irq_cpumask); - cpumask_clear_cpu(cpumask_first(&iucv_irq_cpumask), &cpumask); - for_each_cpu(cpu, &cpumask) + cpumask_copy(cpumask, &iucv_irq_cpumask); + cpumask_clear_cpu(cpumask_first(&iucv_irq_cpumask), cpumask); + for_each_cpu(cpu, cpumask) smp_call_function_single(cpu, iucv_block_cpu, NULL, 1); + + free_cpumask_var(cpumask); } /* @@ -628,23 +633,33 @@ static int iucv_cpu_online(unsigned int cpu) static int iucv_cpu_down_prep(unsigned int cpu) { - cpumask_t cpumask; + cpumask_var_t cpumask; + int ret = 0; if (!iucv_path_table) return 0; - cpumask_copy(&cpumask, &iucv_buffer_cpumask); - cpumask_clear_cpu(cpu, &cpumask); - if (cpumask_empty(&cpumask)) + if (!alloc_cpumask_var(&cpumask, GFP_KERNEL)) + return -ENOMEM; + + cpumask_copy(cpumask, &iucv_buffer_cpumask); + cpumask_clear_cpu(cpu, cpumask); + if (cpumask_empty(cpumask)) { /* Can't offline last IUCV enabled cpu. */ - return -EINVAL; + ret = -EINVAL; + goto __free_cpumask; + } iucv_retrieve_cpu(NULL); if (!cpumask_empty(&iucv_irq_cpumask)) - return 0; + goto __free_cpumask; + smp_call_function_single(cpumask_first(&iucv_buffer_cpumask), iucv_allow_cpu, NULL, 1); - return 0; + +__free_cpumask: + free_cpumask_var(cpumask); + return ret; } /**