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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id ED122C433EF for ; Mon, 28 Mar 2022 15:54:50 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 51BAF8D0002; Mon, 28 Mar 2022 11:54:50 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 4870B8D0001; Mon, 28 Mar 2022 11:54:50 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 2CF1A8D0002; Mon, 28 Mar 2022 11:54:50 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0061.hostedemail.com [216.40.44.61]) by kanga.kvack.org (Postfix) with ESMTP id 1840B8D0001 for ; Mon, 28 Mar 2022 11:54:50 -0400 (EDT) Received: from smtpin23.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with ESMTP id C9EE2181D5524 for ; Mon, 28 Mar 2022 15:54:49 +0000 (UTC) X-FDA: 79294243098.23.E790999 Received: from mail-yb1-f174.google.com (mail-yb1-f174.google.com [209.85.219.174]) by imf08.hostedemail.com (Postfix) with ESMTP id F3F8E160013 for ; Mon, 28 Mar 2022 15:54:48 +0000 (UTC) Received: by mail-yb1-f174.google.com with SMTP id o5so26810752ybe.2 for ; Mon, 28 Mar 2022 08:54:48 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bytedance-com.20210112.gappssmtp.com; s=20210112; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=31O2LB6AcOml2RvdEO4cG6BOTLKDOLVfeCmGtEajMX8=; b=S98nLmUUrDhBhHegmQ5svh/O0gzKAdC3PNpDyhpSw32nh071Ot7mN3sU4DnO2NbkGT jCUnY1si56ypC/v3LdAd5DDzfonYfJNRsJJ7ewOzYNOMA95Nkx994w+O4JPfBIgD0A4i Xia5QSO1bXP1+O1OMGgPD8DY/8GLSmc1axTuYAh/qFy1eQ29TKEM2UT6xZPQU/0NaZrz rdT3B+SCmeBv1bzWbyyfPS629Vm+Q0cklx2lR9kpsMEgZh65GUpqEV0ih08QEaqnSPln tG8ZsPJ5RC4DjeEmnRPgSjWsg5a1eQwc7g1Q16uhkzMmepJxMgpg9drYPFqvUEB1GUiw MViw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=31O2LB6AcOml2RvdEO4cG6BOTLKDOLVfeCmGtEajMX8=; b=xBhoErNvNLK7de1k6j0lTee9hL/J4niNdSjeizwDoR6HQYas8RPGLIADcbYtFuMefy bSiSwP/iPA4Et0VXyIflZHMQkTVU5+xoAFcI9whGoHt0hIvAC+4aNzauRp8eJLwaTLta uPCjfUFXTcO9wSZYcB+nAOjOWQIJ5rIOUgb7QmrWg2UbbVEwrIQuUkQGIEHg4/qzrG/K VbuEDMGW9sNlUA8ugDe6Le87Gn+9R9ynZ5+4wveeaFkzhHcn1I1KJaHlOj7KMj/iaGwM uyTV4zetAc0qhzZol0S19CH8FH3jO9UlL1QWhuFZFdW629YQB+673xj8kJ0pAYNgbOyF eEBw== X-Gm-Message-State: AOAM53275kq0+9XkGsYUXxK4Ktqb6nqQDSLbGLYHZTkJtN6rjyNttDOX QnJuud6xPJa5iz8q4xqFNKvmcVbHw+3WzxZST/UNBA== X-Google-Smtp-Source: ABdhPJzXbFEqKHmcIxRIlfeH0PTYtoH4ZUZ9rq3o2b2Qr7LYC3v04DKb1Lgb4m2+iRheFiZfoS8MtkQkEqQ61wPtDVo= X-Received: by 2002:a05:6902:70c:b0:634:73ef:e663 with SMTP id k12-20020a056902070c00b0063473efe663mr24680640ybt.246.1648482888370; Mon, 28 Mar 2022 08:54:48 -0700 (PDT) MIME-Version: 1.0 References: <20220328132843.16624-1-songmuchun@bytedance.com> In-Reply-To: From: Muchun Song Date: Mon, 28 Mar 2022 23:54:12 +0800 Message-ID: Subject: Re: [PATCH v2] mm: kfence: fix objcgs vector allocation To: Marco Elver Cc: Alexander Potapenko , Dmitry Vyukov , Andrew Morton , kasan-dev , Linux Memory Management List , LKML , Xiongchun duan Content-Type: text/plain; charset="UTF-8" X-Rspamd-Server: rspam04 X-Rspamd-Queue-Id: F3F8E160013 X-Stat-Signature: w3e3qj6c7cfcbqpfdnzu5n3kqzqeo6z8 Authentication-Results: imf08.hostedemail.com; dkim=pass header.d=bytedance-com.20210112.gappssmtp.com header.s=20210112 header.b=S98nLmUU; dmarc=pass (policy=none) header.from=bytedance.com; spf=pass (imf08.hostedemail.com: domain of songmuchun@bytedance.com designates 209.85.219.174 as permitted sender) smtp.mailfrom=songmuchun@bytedance.com X-Rspam-User: X-HE-Tag: 1648482888-901999 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: On Mon, Mar 28, 2022 at 11:51 PM Muchun Song wrote: > > On Mon, Mar 28, 2022 at 11:43 PM Marco Elver wrote: > > > > On Mon, 28 Mar 2022 at 15:28, Muchun Song wrote: > > > > > > If the kfence object is allocated to be used for objects vector, then > > > this slot of the pool eventually being occupied permanently since > > > the vector is never freed. The solutions could be 1) freeing vector > > > when the kfence object is freed or 2) allocating all vectors statically. > > > Since the memory consumption of object vectors is low, it is better to > > > chose 2) to fix the issue and it is also can reduce overhead of vectors > > > allocating in the future. > > > > > > Fixes: d3fb45f370d9 ("mm, kfence: insert KFENCE hooks for SLAB") > > > Signed-off-by: Muchun Song > > > > Reviewed-by: Marco Elver > > Thanks. > > > > > Btw, how did you test this? > > I have tested it with syzkaller with the following configs. And I didn't find any issues. CONFIG_KFENCE=y CONFIG_KFENCE_SAMPLE_INTERVAL=10 CONFIG_KFENCE_NUM_OBJECTS=2550 CONFIG_KFENCE_DEFERRABLE=n CONFIG_KFENCE_STATIC_KEYS=y CONFIG_KFENCE_STRESS_TEST_FAULTS=0