From patchwork Mon Oct 17 03:06:09 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hou Wenlong X-Patchwork-Id: 13008133 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7DEBFC4332F for ; Mon, 17 Oct 2022 03:07:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231853AbiJQDHY (ORCPT ); Sun, 16 Oct 2022 23:07:24 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:54308 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231852AbiJQDG5 (ORCPT ); Sun, 16 Oct 2022 23:06:57 -0400 Received: from out0-150.mail.aliyun.com (out0-150.mail.aliyun.com [140.205.0.150]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1D4F54B4BA; Sun, 16 Oct 2022 20:06:44 -0700 (PDT) X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R121e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=ay29a033018047202;MF=houwenlong.hwl@antgroup.com;NM=1;PH=DS;RN=11;SR=0;TI=SMTPD_---.PeP-vlI_1665975970; Received: from localhost(mailfrom:houwenlong.hwl@antgroup.com fp:SMTPD_---.PeP-vlI_1665975970) by smtp.aliyun-inc.com; Mon, 17 Oct 2022 11:06:11 +0800 From: "Hou Wenlong" To: kvm@vger.kernel.org Cc: Sean Christopherson , Paolo Bonzini , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , x86@kernel.org, "H. Peter Anvin" , Peter Xu , linux-kernel@vger.kernel.org Subject: [PATCH v2 1/2] KVM: x86: Reduce refcount if single_open() fails in kvm_mmu_rmaps_stat_open() Date: Mon, 17 Oct 2022 11:06:09 +0800 Message-Id: <5ddb7c97d2f1edbd000020aa842b0619374e6951.1665975828.git.houwenlong.hwl@antgroup.com> X-Mailer: git-send-email 2.31.1 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Refcount is increased before calling single_open() in kvm_mmu_rmaps_stat_open(), If single_open() fails, refcount should be restored, otherwise the vm couldn't be destroyed. Fixes: 3bcd0662d66fd ("KVM: X86: Introduce mmu_rmaps_stat per-vm debugfs file") Signed-off-by: Hou Wenlong Reviewed-by: Peter Xu --- arch/x86/kvm/debugfs.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/arch/x86/kvm/debugfs.c b/arch/x86/kvm/debugfs.c index cfed36aba2f7..e6efd0821c59 100644 --- a/arch/x86/kvm/debugfs.c +++ b/arch/x86/kvm/debugfs.c @@ -157,12 +157,17 @@ static int kvm_mmu_rmaps_stat_show(struct seq_file *m, void *v) static int kvm_mmu_rmaps_stat_open(struct inode *inode, struct file *file) { + int ret; struct kvm *kvm = inode->i_private; if (!kvm_get_kvm_safe(kvm)) return -ENOENT; - return single_open(file, kvm_mmu_rmaps_stat_show, kvm); + ret = single_open(file, kvm_mmu_rmaps_stat_show, kvm); + if (ret) + kvm_put_kvm(kvm); + + return ret; } static int kvm_mmu_rmaps_stat_release(struct inode *inode, struct file *file) From patchwork Mon Oct 17 03:06:10 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Hou Wenlong X-Patchwork-Id: 13008130 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id B8BF1C433FE for ; Mon, 17 Oct 2022 03:06:30 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231411AbiJQDG1 (ORCPT ); Sun, 16 Oct 2022 23:06:27 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53926 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231784AbiJQDGY (ORCPT ); Sun, 16 Oct 2022 23:06:24 -0400 Received: from out0-149.mail.aliyun.com (out0-149.mail.aliyun.com [140.205.0.149]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 02FDA4B0E2; Sun, 16 Oct 2022 20:06:14 -0700 (PDT) X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R191e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=ay29a033018047204;MF=houwenlong.hwl@antgroup.com;NM=1;PH=DS;RN=3;SR=0;TI=SMTPD_---.PeQJoS4_1665975971; Received: from localhost(mailfrom:houwenlong.hwl@antgroup.com fp:SMTPD_---.PeQJoS4_1665975971) by smtp.aliyun-inc.com; Mon, 17 Oct 2022 11:06:12 +0800 From: "Hou Wenlong" To: kvm@vger.kernel.org Cc: Paolo Bonzini , linux-kernel@vger.kernel.org Subject: [PATCH v2 2/2] KVM: debugfs: Return retval of simple_attr_open() if it fails Date: Mon, 17 Oct 2022 11:06:10 +0800 Message-Id: <69d64d93accd1f33691b8a383ae555baee80f943.1665975828.git.houwenlong.hwl@antgroup.com> X-Mailer: git-send-email 2.31.1 In-Reply-To: <5ddb7c97d2f1edbd000020aa842b0619374e6951.1665975828.git.houwenlong.hwl@antgroup.com> References: <5ddb7c97d2f1edbd000020aa842b0619374e6951.1665975828.git.houwenlong.hwl@antgroup.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org Although simple_attr_open() fails only with -ENOMEM with current code base, it would be nicer to return retval of simple_attr_open() directly in kvm_debugfs_open(). No functional change intended. Signed-off-by: Hou Wenlong --- virt/kvm/kvm_main.c | 13 ++++++------- 1 file changed, 6 insertions(+), 7 deletions(-) diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index e30f1b4ecfa5..f7b06c1e8827 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -5398,6 +5398,7 @@ static int kvm_debugfs_open(struct inode *inode, struct file *file, int (*get)(void *, u64 *), int (*set)(void *, u64), const char *fmt) { + int ret; struct kvm_stat_data *stat_data = (struct kvm_stat_data *) inode->i_private; @@ -5409,15 +5410,13 @@ static int kvm_debugfs_open(struct inode *inode, struct file *file, if (!kvm_get_kvm_safe(stat_data->kvm)) return -ENOENT; - if (simple_attr_open(inode, file, get, - kvm_stats_debugfs_mode(stat_data->desc) & 0222 - ? set : NULL, - fmt)) { + ret = simple_attr_open(inode, file, get, + kvm_stats_debugfs_mode(stat_data->desc) & 0222 + ? set : NULL, fmt); + if (ret) kvm_put_kvm(stat_data->kvm); - return -ENOMEM; - } - return 0; + return ret; } static int kvm_debugfs_release(struct inode *inode, struct file *file)