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[209.85.167.53]) by smtp.gmail.com with ESMTPSA id y8sm383945lfj.192.2021.06.10.12.51.04 for (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 10 Jun 2021 12:51:06 -0700 (PDT) Received: by mail-lf1-f53.google.com with SMTP id f30so5064497lfj.1 for ; Thu, 10 Jun 2021 12:51:04 -0700 (PDT) X-Received: by 2002:a05:6512:3f82:: with SMTP id x2mr266721lfa.421.1623354664442; Thu, 10 Jun 2021 12:51:04 -0700 (PDT) MIME-Version: 1.0 References: <192c9697e379bf084636a8213108be6c3b948d0b.camel@trillion01.com> <9692dbb420eef43a9775f425cb8f6f33c9ba2db9.camel@trillion01.com> <87h7i694ij.fsf_-_@disp2133> <198e912402486f66214146d4eabad8cb3f010a8e.camel@trillion01.com> <87eeda7nqe.fsf@disp2133> <87pmwt6biw.fsf@disp2133> <87czst5yxh.fsf_-_@disp2133> <87y2bh4jg5.fsf@disp2133> In-Reply-To: <87y2bh4jg5.fsf@disp2133> From: Linus Torvalds Date: Thu, 10 Jun 2021 12:50:48 -0700 X-Gmail-Original-Message-ID: Message-ID: Subject: Re: [CFT}[PATCH] coredump: Limit what can interrupt coredumps To: "Eric W. Biederman" Cc: Olivier Langlois , Linux Kernel Mailing List , linux-fsdevel , io-uring , Alexander Viro , Jens Axboe , "Pavel Begunkov>" , Oleg Nesterov Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jun 10, 2021 at 12:18 PM Eric W. Biederman wrote: > > I just didn't want those two lines hiding any other issues we might > have in the coredumps. > > That is probably better development thinking than minimal fix thinking. Well, I think we should first do the minimal targeted fix (the part in fs/coredump.c). Then we should look at whether we could do cleanups as a result of that fix. And I suspect the cleanups might bigger than the two-liner removal. The whole SIGNAL_GROUP_COREDUMP flag was introduced for this issue, See commit 403bad72b67d ("coredump: only SIGKILL should interrupt the coredumping task") which introduced this all. Now, we have since grown other users of SIGNAL_GROUP_COREDUMP - OOM hanmdling and the clear_child_tid thing in mm_release(). So maybe we should keep SIGNAL_GROUP_COREDUMP around. So maybe only those two lines end up being the ones to remove, but I'd really like to think of it as a separate thing from the fix itself. Linus