From mboxrd@z Thu Jan 1 00:00:00 1970 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 E9A7AC00140 for ; Wed, 10 Aug 2022 15:19:06 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233089AbiHJPTF (ORCPT ); Wed, 10 Aug 2022 11:19:05 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33506 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233058AbiHJPSz (ORCPT ); Wed, 10 Aug 2022 11:18:55 -0400 Received: from mail-pj1-x102b.google.com (mail-pj1-x102b.google.com [IPv6:2607:f8b0:4864:20::102b]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 79B93785AA; Wed, 10 Aug 2022 08:18:54 -0700 (PDT) Received: by mail-pj1-x102b.google.com with SMTP id h21-20020a17090aa89500b001f31a61b91dso2489711pjq.4; Wed, 10 Aug 2022 08:18:54 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc; bh=bZ/Wn/pmwYaPcD9cZLDVbMlygpn2TOkNAIPIYOEl18Y=; b=UZqCbeSc22sRQWZd+RhChsE4dWDPqNKHL76pEEfMY+wqnZlJvi6cRD7ua3Gaa60Hx2 CAe+jsbYkYFPiO2urZ+gNwzPkswhX8P0vMpj8kKJGHPQ+3whiPae54/J0ZRSQ/HUIw4B GITX56ZlyJ5jtzQDQa12XN0EVx46NDz6G7X3il4CfvEWFw0pzGMhzGX0FQfo2O4I5fl0 6vwdFXlgkQtZdunmCOOYvrWeJucbUnlSiHYu5+Qqa+6oExySt+Nbsc0oR8SefojbHSD9 iIEse4WYr2CbqGdES+DpvJs+NgjMIojCwVyx/xCV9KBNBYjgwRrPd6c0jRxVHhGKeHt+ M59Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc; bh=bZ/Wn/pmwYaPcD9cZLDVbMlygpn2TOkNAIPIYOEl18Y=; b=xgmB8hCCjUwrjZ2xUt9QYROpZ5I7w2AufTIU7Va1zYTAnbvqUPItn6vGqupiRUQkWY uJDCKR9YEbLSq3cnYUNwoq2KqkeurkdQ7gJ0Ne4UxygEac+zAfrAizKo0ptPusyqHZMc Zc1ox3nWOZmXZCAtvTzHP1xi2e4Wm5POir9nWQgHktUFxLUz6zkGr/VnOJpKNr3nTOvn bOVHqVhchctJB5Ex6F9E0+2ofw1TjJd4DJYeJcxfrLBwov/iQojizQadfoy1V5jPO1ig 3DOX5NOzojoZd2pvVxGwX4RmGLZBJfZls2ommYnaQ68LupZ0dR/Gi7aS2nLR0drfpFJF tnNg== X-Gm-Message-State: ACgBeo1UhccFjfPuK2V+O9d6cZjFZ2ROXiZRawIkP+yOVAFoZ5B8iT03 dlp0Jx+y5ZSqPl8LukVFCdU= X-Google-Smtp-Source: AA6agR7zMPKqwoHrBCMJ/QFxg4BZHomKAMIsFVdSEpWqsvP46BAFZwZnz8InOPJ0E3RrAROE/EQdgA== X-Received: by 2002:a17:902:ccd0:b0:16c:5d4f:99f3 with SMTP id z16-20020a170902ccd000b0016c5d4f99f3mr27988073ple.139.1660144733978; Wed, 10 Aug 2022 08:18:53 -0700 (PDT) Received: from vultr.guest ([2001:19f0:6001:5c3e:5400:4ff:fe19:c3bc]) by smtp.gmail.com with ESMTPSA id 85-20020a621558000000b0052b6ed5ca40sm2071935pfv.192.2022.08.10.08.18.52 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 10 Aug 2022 08:18:53 -0700 (PDT) From: Yafang Shao To: ast@kernel.org, daniel@iogearbox.net, andrii@kernel.org, kafai@fb.com, songliubraving@fb.com, yhs@fb.com, john.fastabend@gmail.com, kpsingh@kernel.org, sdf@google.com, haoluo@google.com, jolsa@kernel.org, hannes@cmpxchg.org, mhocko@kernel.org, roman.gushchin@linux.dev, shakeelb@google.com, songmuchun@bytedance.com, akpm@linux-foundation.org Cc: netdev@vger.kernel.org, bpf@vger.kernel.org, linux-mm@kvack.org, Yafang Shao Subject: [PATCH bpf-next 05/15] bpf: Fix incorrect mem_cgroup_put Date: Wed, 10 Aug 2022 15:18:30 +0000 Message-Id: <20220810151840.16394-6-laoar.shao@gmail.com> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20220810151840.16394-1-laoar.shao@gmail.com> References: <20220810151840.16394-1-laoar.shao@gmail.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: bpf@vger.kernel.org The memcg may be the root_mem_cgroup, in which case we shouldn't put it. So a new helper bpf_map_put_memcg() is introduced to pair with bpf_map_get_memcg(). Fixes: 4201d9ab3e42 ("bpf: reparent bpf maps on memcg offlining") Cc: Roman Gushchin Cc: Shakeel Butt Signed-off-by: Yafang Shao --- kernel/bpf/syscall.c | 14 +++++++++++--- 1 file changed, 11 insertions(+), 3 deletions(-) diff --git a/kernel/bpf/syscall.c b/kernel/bpf/syscall.c index 83c7136..51ab8b1 100644 --- a/kernel/bpf/syscall.c +++ b/kernel/bpf/syscall.c @@ -441,6 +441,14 @@ static struct mem_cgroup *bpf_map_get_memcg(const struct bpf_map *map) return root_mem_cgroup; } +static void bpf_map_put_memcg(struct mem_cgroup *memcg) +{ + if (mem_cgroup_is_root(memcg)) + return; + + mem_cgroup_put(memcg); +} + void *bpf_map_kmalloc_node(const struct bpf_map *map, size_t size, gfp_t flags, int node) { @@ -451,7 +459,7 @@ void *bpf_map_kmalloc_node(const struct bpf_map *map, size_t size, gfp_t flags, old_memcg = set_active_memcg(memcg); ptr = kmalloc_node(size, flags | __GFP_ACCOUNT, node); set_active_memcg(old_memcg); - mem_cgroup_put(memcg); + bpf_map_put_memcg(memcg); return ptr; } @@ -465,7 +473,7 @@ void *bpf_map_kzalloc(const struct bpf_map *map, size_t size, gfp_t flags) old_memcg = set_active_memcg(memcg); ptr = kzalloc(size, flags | __GFP_ACCOUNT); set_active_memcg(old_memcg); - mem_cgroup_put(memcg); + bpf_map_put_memcg(memcg); return ptr; } @@ -480,7 +488,7 @@ void __percpu *bpf_map_alloc_percpu(const struct bpf_map *map, size_t size, old_memcg = set_active_memcg(memcg); ptr = __alloc_percpu_gfp(size, align, flags | __GFP_ACCOUNT); set_active_memcg(old_memcg); - mem_cgroup_put(memcg); + bpf_map_put_memcg(memcg); return ptr; } -- 1.8.3.1