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Fri, 18 Sep 2026 09:41:50 -0400 X-MC-Unique: H0K6Lj2APcaU4-gCZgc4kA-1 X-Mimecast-MFC-AGG-ID: H0K6Lj2APcaU4-gCZgc4kA_1789738909 Received: from mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.111]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id D66E819776A8; Fri, 18 Sep 2026 13:41:47 +0000 (UTC) Received: from fedora (headnet03.pony-001.prod.iad2.dc.redhat.com [10.2.32.114]) by mx-prod-int-08.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with SMTP id 3B334180034C; Fri, 18 Sep 2026 13:41:44 +0000 (UTC) Received: by fedora (nbSMTP-1.00) for uid 1000 oleg@redhat.com; Fri, 18 Sep 2026 15:41:47 +0200 (CEST) Date: Fri, 18 Sep 2026 15:41:42 +0200 From: Oleg Nesterov To: Christian Brauner Cc: Jens Axboe , linux-fsdevel@vger.kernel.org, Alexander Viro , Jan Kara , NeilBrown , Ingo Molnar , Peter Zijlstra , linux-mm@kvack.org, io-uring@vger.kernel.org, stable@vger.kernel.org Subject: Re: [PATCH v2 1/7] fork: refuse new threads while a coredump or an exec is in progress Message-ID: References: <20260917-work-coredump-fixes-v2-0-f3787fcda051@kernel.org> <20260917-work-coredump-fixes-v2-1-f3787fcda051@kernel.org> <20260918-irrsinn-pickt-vermummen-d7167c397398@brauner> <20260918-disput-maden-parkdeck-2bc22dd90398@brauner> MIME-Version: 1.0 In-Reply-To: <20260918-disput-maden-parkdeck-2bc22dd90398@brauner> X-Scanned-By: MIMEDefang 3.4.1 on 10.30.177.111 X-Mimecast-MFC-PROC-ID: jDMIx3zF1KnTPPs2S6ToTEM4NEWYdqUEHxc36-EjZgo_1789738909 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=us-ascii Content-Disposition: inline X-Rspam-User: X-Stat-Signature: 74qehrqp4usxy6iqasg4w9qht4wdk18b X-Rspamd-Queue-Id: 1E68D4000C X-Rspamd-Server: rspam07 X-HE-Tag: 1789738919-619631 X-HE-Meta: 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 Tzt8Nq6G OYNjzDAHd2G/Ui1iuVWY4Ze/3AK8Z+/5/r5r35l6OyE0i/ondkGp/RlKmFw7cB/ZMNdngCbPdVbuynFZIs1eIy/glECf7zbo22MOws7RPAisOyqimPkYw3pfNRgFm5oJgyOQGnnrZbk3m2tfkRBVTEzLrPWpKO/qjGgSpF0dEgtKjewvyja8wrAD7glIAj6fr87zFXn42PMMSZN8M8HoSiVh/L54Hge3UzUnRiTO8VTGJEx59G6JWhX52IknWbP9tjgfEh9MrFoosm6idWdCQPx/XGpIlXpHy687BGQaEGg876p0jS5QI7ACMUqWR2mR9KG4Lv64EM9HCs6W7mw825e5+BAPW7napp5t1 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On 09/18, Christian Brauner wrote: > > I think this works but they also need to check ->in_execve as the > exec'ing thread is obviously never signaled: > > @@ -2709,6 +2707,10 @@ struct task_struct *create_io_thread(int (*fn)(void *), void *arg, int node) > .user_worker = 1, > }; > > + /* A creator past its fatal signal or in execve gets no thread. */ > + if ((current->flags & PF_SIGNALED) || current->in_execve) > + return ERR_PTR(-EINTR); Ah, I forgot to mention... Can we shift io_uring_task_cancel() up, after setting bprm->point_of_no_return but before de_thread() ? I know nothing about io_uring, not sure this would be enough... Oleg.