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 6A454185E42; Wed, 3 Jul 2024 10:47:00 +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=1720003620; cv=none; b=cbpGD8ZKTWRCrrs+ep4jPldcRwQzJTuP67Bq8mpOnu2Ay+TS2wTNypIY4ssib4DzPUuYzKh5QTzJiFeFiVfbxtNE/xuQyM/aTiIFgicLRSw610yQVoc3HeEOH4mB7f0YmlgGqGf+Gzpqh2CaajursBoTEBrzbHSHzA37LwO8DLE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1720003620; c=relaxed/simple; bh=sx61Rs6ng2K2kigNADBOQIDItXw7akqU29JC6Z+Izlc=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=Ifi1Udm6Fp08GdR0s28nFw/+52Q7HVulTpRhLZrrvwhyjuy5Kw51wWj9EaT11jHMQgkeL24Lva0vnYiQXU41TCwP2e+wtlgSULAFV+gDJx9PhjbcB3SmbVYgUwIKV57VTbqa6innZgE3A+jADU3GqYuaUPwHcVMJ9e8VoKSgSVo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=KCQlTXvi; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="KCQlTXvi" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7F221C2BD10; Wed, 3 Jul 2024 10:46:59 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1720003619; bh=sx61Rs6ng2K2kigNADBOQIDItXw7akqU29JC6Z+Izlc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=KCQlTXviePVLJ8MyXQ+U4n0irSwEbzPLtf+2lHEmSVF8pHsLD/wsAn61LzCihk+MW RDHbUgSz/2I/KaECp5WgzHzj8qcsO8WaRJTja7zgSV3601WMyXddD/iSNJfWR4u8e0 o0Q1QyzfSybINX+6TuF6DxLExJSnsDduBFyM+tyU= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Dawei Li , Alexandra Winter , Jakub Kicinski , Sasha Levin Subject: [PATCH 4.19 108/139] net/iucv: Avoid explicit cpumask var allocation on stack Date: Wed, 3 Jul 2024 12:40:05 +0200 Message-ID: <20240703102834.520286893@linuxfoundation.org> X-Mailer: git-send-email 2.45.2 In-Reply-To: <20240703102830.432293640@linuxfoundation.org> References: <20240703102830.432293640@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 4.19-stable review patch. If anyone has any objections, please let me know. ------------------ From: Dawei Li [ Upstream commit be4e1304419c99a164b4c0e101c7c2a756b635b9 ] 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 Reviewed-by: Alexandra Winter Link: https://lore.kernel.org/r/20240331053441.1276826-2-dawei.li@shingroup.cn Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin --- net/iucv/iucv.c | 26 ++++++++++++++++++-------- 1 file changed, 18 insertions(+), 8 deletions(-) diff --git a/net/iucv/iucv.c b/net/iucv/iucv.c index da4cee91fc63d..2f82a6f0992e4 100644 --- a/net/iucv/iucv.c +++ b/net/iucv/iucv.c @@ -578,7 +578,7 @@ static void iucv_setmask_mp(void) */ static void iucv_setmask_up(void) { - cpumask_t cpumask; + static cpumask_t cpumask; int cpu; /* Disable all cpu but the first in cpu_irq_cpumask. */ @@ -686,23 +686,33 @@ 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; } /** -- 2.43.0