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[157.230.128.187]) by smtp.gmail.com with ESMTPSA id ml17sm6443717pjb.13.2020.04.03.12.49.30 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 03 Apr 2020 12:49:30 -0700 (PDT) Received: by 42.do-not-panic.com (Postfix, from userid 1000) id 7938E40297; Fri, 3 Apr 2020 19:49:29 +0000 (UTC) Date: Fri, 3 Apr 2020 19:49:29 +0000 From: Luis Chamberlain To: Bart Van Assche Cc: Ming Lei , axboe@kernel.dk, viro@zeniv.linux.org.uk, gregkh@linuxfoundation.org, rostedt@goodmis.org, mingo@redhat.com, jack@suse.cz, nstange@suse.de, mhocko@suse.com, linux-block@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, yukuai3@huawei.com Subject: Re: [RFC 0/3] block: address blktrace use-after-free Message-ID: <20200403194929.GZ11244@42.do-not-panic.com> References: <20200402000002.7442-1-mcgrof@kernel.org> <20200403081929.GC6887@ming.t460p> <15236c59-6b48-2fcf-1a84-f98cb8b339ab@acm.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <15236c59-6b48-2fcf-1a84-f98cb8b339ab@acm.org> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Apr 03, 2020 at 07:13:47AM -0700, Bart Van Assche wrote: > On 2020-04-03 01:19, Ming Lei wrote: > > BTW, Yu Kuai posted one patch for this issue, looks that approach > > is simpler: > > > > https://lore.kernel.org/linux-block/20200324132315.22133-1-yukuai3@huawei.com/ > > That approach is indeed simpler but at the expense of performing dynamic > memory allocation in a cleanup path, something I'm not enthusiast about. I also think that its important to annotate that there are actually two issues here. Not one. One is the misuse of debugfs, the other is how the deferral exposed the misuse and complications of its misuse. Luis