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[2620:137:e000::1:20]) by mx.google.com with ESMTP id m16-20020a056402511000b00426499ad159si1281007edd.162.2022.05.05.01.23.05; Thu, 05 May 2022 01:23:28 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20; Authentication-Results: mx.google.com; dkim=pass header.i=@linutronix.de header.s=2020 header.b=1MWan81q; dkim=neutral (no key) header.i=@linutronix.de header.b=odQlOZT0; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=QUARANTINE dis=NONE) header.from=linutronix.de Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1378510AbiEDVOv (ORCPT + 99 others); Wed, 4 May 2022 17:14:51 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59036 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1358477AbiEDVOt (ORCPT ); Wed, 4 May 2022 17:14:49 -0400 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 81AED49FB4 for ; Wed, 4 May 2022 14:11:12 -0700 (PDT) From: John Ogness DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1651698671; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=CKPWYgbYXcfIsG95x1ua8STRPsIFuKN1LA1dfgcwhhA=; b=1MWan81qhvKGVvbdBCrUwXV2WiAmiNVsoUUJGH95QqQOMCpw0T4wgYf4A+g2olyc52bhX5 iPkjnQLkzaMTi6VwTaowiIS8cbMF7deB2YVuXC6CUU1VPuQ0YyXE1YyRKgqSVh1BMx6NGY PH7E3XlFBlJH0+YsLdSpZOxcxPkVBmlBZUuac+FRKCc1CbnblGRLezF+pnd2zkQkPYobde NaJitdWbNoqLmjxim0r4NRHMYq9KhbymOq1JeraQhNiJCk1xWoFypAIhsCW0HAdWfFsUFL 3/ne/DduUXaQcaFFNpanLge4E7y8ZnNcJfzhpa8/MiaFMZpTtRXJftD4L7GM8w== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1651698671; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=CKPWYgbYXcfIsG95x1ua8STRPsIFuKN1LA1dfgcwhhA=; b=odQlOZT03eWDUW4JUq55Nq9AyO8/0Gcb6em6qQlxjX+3nYEkdyYhLk80Lhp1/T42KeqlyS GYGy6dmQmHzE4bBQ== To: Marek Szyprowski , Petr Mladek Cc: Sergey Senozhatsky , Steven Rostedt , Thomas Gleixner , linux-kernel@vger.kernel.org, Greg Kroah-Hartman , linux-amlogic@lists.infradead.org Subject: Re: [PATCH printk v5 1/1] printk: extend console_lock for per-console locking In-Reply-To: <45849b63-d7a8-5cc3-26ad-256a28d09991@samsung.com> References: <2a82eae7-a256-f70c-fd82-4e510750906e@samsung.com> <87fslyv6y3.fsf@jogness.linutronix.de> <51dfc4a0-f6cf-092f-109f-a04eeb240655@samsung.com> <87k0b6blz2.fsf@jogness.linutronix.de> <32bba8f8-dec7-78aa-f2e5-f62928412eda@samsung.com> <45849b63-d7a8-5cc3-26ad-256a28d09991@samsung.com> Date: Wed, 04 May 2022 23:17:10 +0206 Message-ID: <87pmktm2a9.fsf@jogness.linutronix.de> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable X-Spam-Status: No, score=-3.9 required=5.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,INVALID_DATE_TZ_ABSURD, RCVD_IN_DNSWL_MED,SPF_HELO_NONE,SPF_PASS,T_SCC_BODY_TEXT_LINE autolearn=ham autolearn_force=no version=3.4.6 X-Spam-Checker-Version: SpamAssassin 3.4.6 (2021-04-09) on lindbergh.monkeyblade.net Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2022-05-03, Marek Szyprowski wrote: > QEMU virt/arm64: > > [=C2=A0 174.155760] task:pr/ttyAMA0=C2=A0=C2=A0=C2=A0=C2=A0=C2=A0 state:S= stack:=C2=A0=C2=A0=C2=A0 0 pid:=C2=A0=C2=A0 26=20 > ppid:=C2=A0=C2=A0=C2=A0=C2=A0 2 flags:0x00000008 > [=C2=A0 174.156305] Call trace: > [=C2=A0 174.156529]=C2=A0 __switch_to+0xe8/0x160 > [=C2=A0 174.157131]=C2=A0 0xffff5ebbbfdd62d8 I can reproduce the apparent stack corruption with qemu: [ 5.545268] task:pr/ttyAMA0 state:S stack: 0 pid: 26 ppid: = 2 flags:0x00000008 [ 5.545520] Call trace: [ 5.545620] __switch_to+0x104/0x160 [ 5.545796] __schedule+0x2f4/0x9f0 [ 5.546122] schedule+0x54/0xd0 [ 5.546206] 0x0 When it happens, the printk-kthread is the only one with the corrupted stack. It seems I am doing something wrong when creating the kthread? I will investigate this. Thanks Marek for helping us to narrow this down. John