From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 5F763C2BD09 for ; Wed, 3 Jul 2024 10:10:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:MIME-Version: Content-Transfer-Encoding:Content-Type:References:In-Reply-To:Date:To:From: Subject:Message-ID:Reply-To:Cc:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=6VVaJjUHolqbPfOosQJDJvLSCQCfRIiDsfa2LqOaVG0=; b=M9v+Vdaa0J3T3dSj56LTcxu8Qz L9T+hmzKWeqCBfvnzXG+3DUU0+SbQ9NmdKAisvtSKtx9hCqaCcRdX/BwDm6MLDg9DqnwD5RJpx0k1 JnvBOWFEF8+JH+y/Z+HL78Dfn7LWpfkLtsZakazMRuxYQVjGkrmQT45SZFVJa/Xyz0Qvu+QlgQz/o MxQxLbzSFt3XVuVHkabtVySciK+nvksKlosPpTlyh+pzjor114DuAr4VgWg8wU33evdMWLCnqq6Po vje5xBPkN9c6cRuGc/wCJ0OnBG6MKww6LGvvpjwqvwPjS8pPifyI+ElK7JYy7YFgEK/ACR8/sB8V7 sICvqEdQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1sOwwM-00000009go9-2u3D; Wed, 03 Jul 2024 10:10:18 +0000 Received: from s3.sipsolutions.net ([2a01:4f8:242:246e::2] helo=sipsolutions.net) by bombadil.infradead.org with esmtps (Exim 4.97.1 #2 (Red Hat Linux)) id 1sOwwK-00000009gnH-0eYo for linux-um@lists.infradead.org; Wed, 03 Jul 2024 10:10:17 +0000 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=sipsolutions.net; s=mail; h=MIME-Version:Content-Transfer-Encoding: Content-Type:References:In-Reply-To:Date:To:From:Subject:Message-ID:Sender: Reply-To:Cc:Content-ID:Content-Description:Resent-Date:Resent-From:Resent-To: Resent-Cc:Resent-Message-ID; bh=6VVaJjUHolqbPfOosQJDJvLSCQCfRIiDsfa2LqOaVG0=; t=1720001415; x=1721211015; b=FdlgBMf4ViW0EW7wp7h+x9PyztLsziVE+9dGOoSVMKUrttr uHPlAi2X4L2w2tCdW037kW9yMaOIK/2FujW8NbTrejRAzPqX9rkr19RykcqOGk+GxpU50fwFnC0yz I7/HbkucawDDP3VvSboL5yd2pddS12Zj9+h2phZ/zK7PWWSxJ/tl5fcUJQOO9A0MwlniQVcuNUw+M 6rvBRcJWufdRSlhwnXqsiAtR0w9SKUJmMIreM37obwbkQaFSO2XQH8CP3xAx4LmBGE4whvQMu8R2l UPz0ZBfxG2ORtvKNZCGQiWE5bu6rXbHVLsEmCJxYMWv5ycAXZLZzDamVbvOYw+/g==; Received: by sipsolutions.net with esmtpsa (TLS1.3:ECDHE_X25519__RSA_PSS_RSAE_SHA256__AES_256_GCM:256) (Exim 4.97) (envelope-from ) id 1sOwwG-00000008Zy4-32uU; Wed, 03 Jul 2024 12:10:12 +0200 Message-ID: Subject: Re: [PATCH v3 10/12] um: remove force_flush_all from fork_handler From: Johannes Berg To: Benjamin Berg , linux-um@lists.infradead.org Date: Wed, 03 Jul 2024 12:10:11 +0200 In-Reply-To: References: <20240524213718.1757703-1-benjamin@sipsolutions.net> <20240524213718.1757703-11-benjamin@sipsolutions.net> <2784bb3e9de2ad88a48d8fa70b01c46e1b2399fc.camel@sipsolutions.net> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable User-Agent: Evolution 3.52.3 (3.52.3-1.fc40) MIME-Version: 1.0 X-malware-bazaar: not-scanned X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240703_031016_214791_C278B052 X-CRM114-Status: GOOD ( 14.26 ) X-BeenThere: linux-um@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-um" Errors-To: linux-um-bounces+linux-um=archiver.kernel.org@lists.infradead.org On Wed, 2024-07-03 at 12:08 +0200, Benjamin Berg wrote: > On Wed, 2024-07-03 at 11:45 +0200, Johannes Berg wrote: > > On Fri, 2024-05-24 at 23:37 +0200, benjamin@sipsolutions.net=C2=A0wrote= : > > > From: Benjamin Berg > > >=20 > > > There should be no need for this. > >=20 > > "should" ;-) >=20 > Hmm, I would have expected the previous patch is what breaks it. Ouch, you're right, I replied to the wrong patch - bisected to the previous one indeed. > > This breaks things if glibc enables rseq. That might even be already > > broken in the sense that it might corrupt memory that's put at the same > > place the rseq was installed? But it at least it appears to still work > > without this patch... >=20 > Then it would make sense to me as the previous force_flush_all would > have only unmapped up to TASK_SIZE. While this now uses STUB_START > which clears more memory as TASK_SIZE has some alignment. Right. johannes