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[209.132.180.67]) by mx.google.com with ESMTP id i9si2942879plb.35.2018.12.20.21.55.50; Thu, 20 Dec 2018 21:56:05 -0800 (PST) Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67; Authentication-Results: mx.google.com; dkim=pass header.i=@synopsys.com header.s=mail header.b=OEZjdgq4; spf=pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org; dmarc=pass (p=NONE sp=NONE dis=NONE) header.from=synopsys.com Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2389395AbeLTSnK (ORCPT + 99 others); Thu, 20 Dec 2018 13:43:10 -0500 Received: from smtprelay2.synopsys.com ([198.182.60.111]:38350 "EHLO smtprelay.synopsys.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2389371AbeLTSnK (ORCPT ); Thu, 20 Dec 2018 13:43:10 -0500 Received: from mailhost.synopsys.com (mailhost1.synopsys.com [10.12.238.239]) by smtprelay.synopsys.com (Postfix) with ESMTP id B8C2510C0E00; Thu, 20 Dec 2018 10:43:09 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=synopsys.com; s=mail; t=1545331389; bh=jpwKVNQoclFo4m+mrr0h3pd+OLd0bO1Ut7VNurR2fgo=; h=From:To:CC:Subject:Date:References:From; b=OEZjdgq47MPtTO8OuNCoFfEnaEtaOqaPVXtZDW9tt1PDDug9X8W+as+qFfdseTOHq uzoU5F1sonPNuxkUil6DaAHvha9h2tcNd6YbqdobdTXaxb6URElibyafOTfg/e8yFI jwWHdAposeJXOs1owZFWLBaXTP2wRZIClHe4o+eKlMipdx+QRtT0TL2G9+HZ2AIR2w TonZZfD0JZYy+NMgvIbpLl1kRD/Hhu3VP4xS9mw6DJ369YVy9mkohBZYhUKy9Az+Uz TS0pG2FeHTmzroXIsoofvtAn/s4rt5sxHJidn/23YMrTa7zPLzSbNw/ORAlEJjtdn1 9my9XpbfL8qIA== Received: from US01WEHTC3.internal.synopsys.com (us01wehtc3.internal.synopsys.com [10.15.84.232]) by mailhost.synopsys.com (Postfix) with ESMTP id A5E9C5B81; Thu, 20 Dec 2018 10:43:09 -0800 (PST) Received: from US01WEMBX2.internal.synopsys.com ([fe80::e4b6:5520:9c0d:250b]) by US01WEHTC3.internal.synopsys.com ([::1]) with mapi id 14.03.0415.000; Thu, 20 Dec 2018 10:43:09 -0800 From: Vineet Gupta To: Tetsuo Handa , Eugeniy Paltsev , "linux-snps-arc@lists.infradead.org" CC: "linux-arch@vger.kernel.org" , "linux-mm@kvack.org" , "peterz@infradead.org" , "linux-kernel@vger.kernel.org" , Michal Hocko Subject: Re: [PATCH 1/2] ARC: show_regs: avoid page allocator Thread-Topic: [PATCH 1/2] ARC: show_regs: avoid page allocator Thread-Index: AQHUlwMR8PfsxZ55lUuwqgC40oqmmA== Date: Thu, 20 Dec 2018 18:43:08 +0000 Message-ID: References: <1545159239-30628-1-git-send-email-vgupta@synopsys.com> <1545159239-30628-2-git-send-email-vgupta@synopsys.com> <1545239047.14089.13.camel@synopsys.com> <49f9edc9-87ee-1efc-58f8-b0d9a52c8a49@synopsys.com> Accept-Language: en-US Content-Language: en-US X-MS-Has-Attach: X-MS-TNEF-Correlator: x-originating-ip: [10.144.199.106] Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 12/20/18 5:30 AM, Tetsuo Handa wrote:=0A= >> | Stack Trace:=0A= >> | arc_unwind_core+0xcc/0x100=0A= >> | ___might_sleep+0x17a/0x190=0A= >> | mmput+0x16/0xb8=0A= > Then, does mmput_async() help?=0A= >=0A= =0A= It helps, but then we get the next one (w/o my patch 2/2)=0A= =0A= BUG: sleeping function called from invalid context at kernel/locking/rwsem.= c:23=0A= in_atomic(): 1, irqs_disabled(): 0, pid: 69, name: segv-null-ptr=0A= no locks held by segv-null-ptr/69.=0A= CPU: 0 PID: 69 Comm: segv-null-ptr Not tainted 4.18.0+ #72=0A= =0A= Stack Trace:=0A= arc_unwind_core+0xcc/0x100=0A= ___might_sleep+0x17a/0x190=0A= down_read+0x18/0x38=0A= show_regs+0x102/0x310=0A= get_signal+0x5ee/0x610=0A= do_signal+0x2c/0x218=0A= resume_user_mode_begin+0x90/0xd8=0A= @off 0x103d4 in [/segv-null-pt=0A=