From patchwork Sat Nov 13 15:44:10 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Bui Quang Minh X-Patchwork-Id: 12617711 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 mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id F15DAC433FE for ; Sat, 13 Nov 2021 15:44:46 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 72E7761156 for ; Sat, 13 Nov 2021 15:44:46 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.4.1 mail.kernel.org 72E7761156 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=kvack.org Received: by kanga.kvack.org (Postfix) id C3F396B0075; Sat, 13 Nov 2021 10:44:45 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id BEEC86B0078; Sat, 13 Nov 2021 10:44:45 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id ADCDA6B007B; Sat, 13 Nov 2021 10:44:45 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0165.hostedemail.com [216.40.44.165]) by kanga.kvack.org (Postfix) with ESMTP id 9B3EF6B0075 for ; Sat, 13 Nov 2021 10:44:45 -0500 (EST) Received: from smtpin09.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with ESMTP id 42B99811E7 for ; Sat, 13 Nov 2021 15:44:45 +0000 (UTC) X-FDA: 78804329730.09.1F00F03 Received: from mail-pf1-f170.google.com (mail-pf1-f170.google.com [209.85.210.170]) by imf09.hostedemail.com (Postfix) with ESMTP id DF2EC300011E for ; Sat, 13 Nov 2021 15:44:44 +0000 (UTC) Received: by mail-pf1-f170.google.com with SMTP id c4so11080765pfj.2 for ; Sat, 13 Nov 2021 07:44:44 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=CiFvkxkml/E3hXlk6viC87ZsHB//A7EeJApdZ7JR+24=; b=AhBqsrkR6Fp1PCg8xJzMWdHyQh6BMpzd1VQXjD7eq24JgAEh/aQLmilgvbgj9Lvtl7 1a4y44tdB/zCNR9YJU0t+Y6UiTsUqrn/lZGt+Jl5Xa5JtsB+ExkAPaYJxaPPpz2V35yG uZwtUM7QRU7apJtAZIRfNBpAWt7Oj2kjBnFjLMTRP2IDipBUh7IAQsWZz447GOckgsxp ybzBFRKIRXvJS5FC87J8VL1kCiLk4l8q78MS0GDqFDaJDfK7cVPG3INWdmG+8uXwt/fd mBVcB2mOfhgYKoY+RnlQGPA7MqcfgLypx6gdjK+L5wnHmVJbvvVgPLwtHTfdbUssqi3L oo7g== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:mime-version :content-transfer-encoding; bh=CiFvkxkml/E3hXlk6viC87ZsHB//A7EeJApdZ7JR+24=; b=J54Lpe+hzQZ6SoAsZxjVQO2XwL3cxp5X/07RVBbbC4wBHV1nrV6BsJR21vgfiELU57 1CVAtOKMxjZTI2yjXeuRp5EdPLWKI57ReTSvQglcekCCfGu2IFRd0IVoJCKZYJi7Q3/L pRt0/NsTd0Zn/RaYyE9v6Iz1m2ocxB84U9a/VKjtd5itlUfgniI0la3A9EW/m+mzKfxR ojzgdthMocXXdrsuLZutJTIy3cwUe/lwHRFZWotp6Lo5AZhDYkopYVxJ0A8kFVPeQwgi snBBD+cnP6szWGvtZPRJuYvxw20rJcdnkPmwKURaPjAuYLHmpWlNxIQKkQgi8ytqnvFy oVSQ== X-Gm-Message-State: AOAM530kxHwZjGQnmNqHRAT1+ZPUPgRnHjRJlt0WU+hWsVkI+zWmifys Ak6jQMK/zQh37yJomp9nkcQ= X-Google-Smtp-Source: ABdhPJx1VOktTq/wTyazaQKuTgGuBrVRN5rl7mqgaWSQ9s7vhuM2ASOEpckNlz+ko7kRKquhceum/w== X-Received: by 2002:a62:6184:0:b0:4a2:a063:fe8e with SMTP id v126-20020a626184000000b004a2a063fe8emr2105905pfb.69.1636818283847; Sat, 13 Nov 2021 07:44:43 -0800 (PST) Received: from localhost.localdomain ([113.172.190.100]) by smtp.googlemail.com with ESMTPSA id q13sm10847651pfk.22.2021.11.13.07.44.41 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 13 Nov 2021 07:44:43 -0800 (PST) From: Bui Quang Minh To: Cc: Bui Quang Minh , Mike Kravetz , Andrew Morton , Miaohe Lin , Michal Hocko , Muchun Song , Mina Almasry , linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: [PATCH] hugetlb: fix hugetlb cgroup refcounting during mremap Date: Sat, 13 Nov 2021 22:44:10 +0700 Message-Id: <20211113154412.91134-1-minhquangbui99@gmail.com> X-Mailer: git-send-email 2.25.1 MIME-Version: 1.0 X-Rspamd-Server: rspam03 X-Rspamd-Queue-Id: DF2EC300011E X-Stat-Signature: ec8cyqyw1n96tr7zrhzthmeodaito7uz Authentication-Results: imf09.hostedemail.com; dkim=pass header.d=gmail.com header.s=20210112 header.b=AhBqsrkR; dmarc=pass (policy=none) header.from=gmail.com; spf=pass (imf09.hostedemail.com: domain of minhquangbui99@gmail.com designates 209.85.210.170 as permitted sender) smtp.mailfrom=minhquangbui99@gmail.com X-HE-Tag: 1636818284-72072 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: When hugetlb_vm_op_open() is called during copy_vma(), we may take the reference to resv_map->css. Later, when clearing the reservation pointer of old_vma after transferring it to new_vma, we forget to drop the reference to resv_map->css. This leads to a reference leak of css. Fixes this by adding a check to drop reservation css reference in clear_vma_resv_huge_pages() Fixes: 550a7d6 (mm, hugepages: add mremap() support for hugepage backed vma) Signed-off-by: Bui Quang Minh Reviewed-by: Mina Almasry Reviewed-by: Mike Kravetz css); } +static inline void resv_map_put_hugetlb_cgroup_uncharge_info( + struct resv_map *resv_map) +{ + if (resv_map->css) + css_put(resv_map->css); +} + extern int hugetlb_cgroup_charge_cgroup(int idx, unsigned long nr_pages, struct hugetlb_cgroup **ptr); extern int hugetlb_cgroup_charge_cgroup_rsvd(int idx, unsigned long nr_pages, @@ -211,6 +218,11 @@ static inline void resv_map_dup_hugetlb_cgroup_uncharge_info( { } +static inline void resv_map_put_hugetlb_cgroup_uncharge_info( + struct resv_map *resv_map) +{ +} + static inline int hugetlb_cgroup_charge_cgroup(int idx, unsigned long nr_pages, struct hugetlb_cgroup **ptr) { diff --git a/mm/hugetlb.c b/mm/hugetlb.c index e09159c957e3..3a2479003ddf 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -1037,8 +1037,10 @@ void clear_vma_resv_huge_pages(struct vm_area_struct *vma) */ struct resv_map *reservations = vma_resv_map(vma); - if (reservations && is_vma_resv_set(vma, HPAGE_RESV_OWNER)) + if (reservations && is_vma_resv_set(vma, HPAGE_RESV_OWNER)) { + resv_map_put_hugetlb_cgroup_uncharge_info(reservations); kref_put(&reservations->refs, resv_map_release); + } reset_vma_resv_huge_pages(vma); }