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 EA7131F6694; Mon, 21 Oct 2024 10:48:25 +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=1729507706; cv=none; b=YoZebWUuN4iA889NEKfidEWyIW+PoCRI96EVsvbrwgriceZqL2dQIrl57aLIwSTwONstmOHyN1ojoVIrAJJqqZjh1K/CvmHnRNPNqSt+qFmRRLJNZciB8jfDsjFBSfxEh6c/9EdKpp5Wp4MtQA5UiIn0F/dpy5paZg+KDEC9bw8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729507706; c=relaxed/simple; bh=mLu2dS60X7wBk6Q3UwpXpmatTfbv6suugc6vQ8uFK9o=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=eLvnfELleCsFlKLv4mKbC1TLsEablTXQp4ZLyHZVefZ8rANnL8KbgMB/PPBRZHQG94v6pNmcHD0SmBMkkoRYYXcUBHwsTGplstOMBBl0k3X3fVzvSQ6QRGpex7UWKSWcddy1LUvN3uusBFhqWNMgn5NJuhucfZz4G3KJXGSrYYA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=rFcAwwy/; 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="rFcAwwy/" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 688E7C4CEF0; Mon, 21 Oct 2024 10:48:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1729507705; bh=mLu2dS60X7wBk6Q3UwpXpmatTfbv6suugc6vQ8uFK9o=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=rFcAwwy/A2MtQdlNDKHWJY7LKbHIn0mx3dnIF9zC3/QiARlVZMaQHkW/gbhMlYDUE VbSaGjTSFeKmOGkBoABrkKjTN9y06+DVUj+9lkdllv/2GP4eLt6+ORwbsHGO9Vmelh 55ggVZ4rSmOxlDdCQFxEn3A4a9PDpTVLkH3GDG0I= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Kunkun Jiang , Marc Zyngier , Thomas Gleixner Subject: [PATCH 5.15 73/82] irqchip/gic-v4: Dont allow a VMOVP on a dying VPE Date: Mon, 21 Oct 2024 12:25:54 +0200 Message-ID: <20241021102250.099718376@linuxfoundation.org> X-Mailer: git-send-email 2.47.0 In-Reply-To: <20241021102247.209765070@linuxfoundation.org> References: <20241021102247.209765070@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 5.15-stable review patch. If anyone has any objections, please let me know. ------------------ From: Marc Zyngier commit 1442ee0011983f0c5c4b92380e6853afb513841a upstream. Kunkun Jiang reported that there is a small window of opportunity for userspace to force a change of affinity for a VPE while the VPE has already been unmapped, but the corresponding doorbell interrupt still visible in /proc/irq/. Plug the race by checking the value of vmapp_count, which tracks whether the VPE is mapped ot not, and returning an error in this case. This involves making vmapp_count common to both GICv4.1 and its v4.0 ancestor. Fixes: 64edfaa9a234 ("irqchip/gic-v4.1: Implement the v4.1 flavour of VMAPP") Reported-by: Kunkun Jiang Signed-off-by: Marc Zyngier Signed-off-by: Thomas Gleixner Cc: stable@vger.kernel.org Link: https://lore.kernel.org/r/c182ece6-2ba0-ce4f-3404-dba7a3ab6c52@huawei.com Link: https://lore.kernel.org/all/20241002204959.2051709-1-maz@kernel.org Signed-off-by: Greg Kroah-Hartman --- drivers/irqchip/irq-gic-v3-its.c | 18 ++++++++++++------ include/linux/irqchip/arm-gic-v4.h | 4 +++- 2 files changed, 15 insertions(+), 7 deletions(-) --- a/drivers/irqchip/irq-gic-v3-its.c +++ b/drivers/irqchip/irq-gic-v3-its.c @@ -789,8 +789,8 @@ static struct its_vpe *its_build_vmapp_c its_encode_valid(cmd, desc->its_vmapp_cmd.valid); if (!desc->its_vmapp_cmd.valid) { + alloc = !atomic_dec_return(&desc->its_vmapp_cmd.vpe->vmapp_count); if (is_v4_1(its)) { - alloc = !atomic_dec_return(&desc->its_vmapp_cmd.vpe->vmapp_count); its_encode_alloc(cmd, alloc); /* * Unmapping a VPE is self-synchronizing on GICv4.1, @@ -809,13 +809,13 @@ static struct its_vpe *its_build_vmapp_c its_encode_vpt_addr(cmd, vpt_addr); its_encode_vpt_size(cmd, LPI_NRBITS - 1); + alloc = !atomic_fetch_inc(&desc->its_vmapp_cmd.vpe->vmapp_count); + if (!is_v4_1(its)) goto out; vconf_addr = virt_to_phys(page_address(desc->its_vmapp_cmd.vpe->its_vm->vprop_page)); - alloc = !atomic_fetch_inc(&desc->its_vmapp_cmd.vpe->vmapp_count); - its_encode_alloc(cmd, alloc); /* @@ -3811,6 +3811,13 @@ static int its_vpe_set_affinity(struct i int from, cpu; /* + * Check if we're racing against a VPE being destroyed, for + * which we don't want to allow a VMOVP. + */ + if (!atomic_read(&vpe->vmapp_count)) + return -EINVAL; + + /* * Changing affinity is mega expensive, so let's be as lazy as * we can and only do it if we really have to. Also, if mapped * into the proxy device, we need to move the doorbell @@ -4446,9 +4453,8 @@ static int its_vpe_init(struct its_vpe * raw_spin_lock_init(&vpe->vpe_lock); vpe->vpe_id = vpe_id; vpe->vpt_page = vpt_page; - if (gic_rdists->has_rvpeid) - atomic_set(&vpe->vmapp_count, 0); - else + atomic_set(&vpe->vmapp_count, 0); + if (!gic_rdists->has_rvpeid) vpe->vpe_proxy_event = -1; return 0; --- a/include/linux/irqchip/arm-gic-v4.h +++ b/include/linux/irqchip/arm-gic-v4.h @@ -58,10 +58,12 @@ struct its_vpe { bool enabled; bool group; } sgi_config[16]; - atomic_t vmapp_count; }; }; + /* Track the VPE being mapped */ + atomic_t vmapp_count; + /* * Ensures mutual exclusion between affinity setting of the * vPE and vLPI operations using vpe->col_idx.