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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 57579E75448 for ; Wed, 24 Dec 2025 12:02:09 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 96F416B0005; Wed, 24 Dec 2025 07:02:08 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 91C476B0088; Wed, 24 Dec 2025 07:02:08 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 828B96B008A; Wed, 24 Dec 2025 07:02:08 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0013.hostedemail.com [216.40.44.13]) by kanga.kvack.org (Postfix) with ESMTP id 6EA046B0005 for ; Wed, 24 Dec 2025 07:02:08 -0500 (EST) Received: from smtpin14.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay06.hostedemail.com (Postfix) with ESMTP id D7DB6135111 for ; Wed, 24 Dec 2025 12:02:07 +0000 (UTC) X-FDA: 84254226294.14.0ABFCC7 Received: from sea.source.kernel.org (sea.source.kernel.org [172.234.252.31]) by imf24.hostedemail.com (Postfix) with ESMTP id 2D14418001E for ; Wed, 24 Dec 2025 12:02:05 +0000 (UTC) Authentication-Results: imf24.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=FY1b1b2u; dmarc=pass (policy=quarantine) header.from=kernel.org; spf=pass (imf24.hostedemail.com: domain of brauner@kernel.org designates 172.234.252.31 as permitted sender) smtp.mailfrom=brauner@kernel.org ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1766577726; a=rsa-sha256; cv=none; b=2jvIpdh1Ljoq3pcg6yXiMorBYd4cJLl6DXGMZoBKIzwBXqViKcELjz3ZWMogVTeK9r3Mnn 17ac5uYmQRK6sGpFmMSAXholeKFDv7aeJ4sjiAols7WZsUTvhQuaSUOf1LUsy3KuSy6LWd datC8ybrkBS1JD0Sm1JMW8XNaQeeOW8= ARC-Authentication-Results: i=1; imf24.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=FY1b1b2u; dmarc=pass (policy=quarantine) header.from=kernel.org; spf=pass (imf24.hostedemail.com: domain of brauner@kernel.org designates 172.234.252.31 as permitted sender) smtp.mailfrom=brauner@kernel.org ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1766577726; h=from:from:sender: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: in-reply-to:in-reply-to:references:references:dkim-signature; bh=BRazb//YpBUuXuQsI7NHiELei7PSTpncdZMv9ssRZN0=; b=D6mgaSEMDe+vGTY9waD4yjTpP3WfCxbmiiO9Dk+vwSuW6I3PTS4OvEZcOITN/vgDsLkZXk hgquiJ6VmMegtIQaiirmZZ9s8oKwjX6rx/cHdcDx7GzRxqOw5R4IF3NocK/eSQ9oQ27+ME /SAbUM8fqtTJHOIBH7dYY0R+gQQj8O4= Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by sea.source.kernel.org (Postfix) with ESMTP id 248CE42DBB; Wed, 24 Dec 2025 12:02:05 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 64201C4CEFB; Wed, 24 Dec 2025 12:02:01 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1766577725; bh=uBPqXxyHezu6KXMQBRpWZz+nm9zp7C2D106puhEjv7o=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=FY1b1b2utCFXPMdOoq8ndCNnjTuXNaW7HmED9XfyIybn9/6t4O9TBn6CrzTWmRCBf DzV0uk8sNGWBHT0e0hIJUUGnFPYUjyDW438hnokF+br63eXJfp1opNni5v2uh3xMHn EPuLx/iua/0vEldXwaiE1aTVrKqT+IgrWn5jCTM9EKb6e0Rb20IllUtj34SGr5zowJ 1AhUcBmkCZziavlIh6PfLNzEly5DYHo0poNTxs+al9f1yoz9Q4NyW58X7WsFXoqdjX gof0rFbzXjx98ncanny1FHY1o5Vr/pKtrsxnQITJXnPcY6CRmzOnLvG8tGwfW8pkYV gdXFNgVCx1agA== Date: Wed, 24 Dec 2025 13:01:58 +0100 From: Christian Brauner To: Shakeel Butt Cc: Andrew Morton , Matthew Wilcox , Andrii Nakryiko , Shaurya Rane , "Darrick J . Wong" , Christoph Hellwig , Alexei Starovoitov , Daniel Borkmann , bpf@vger.kernel.org, linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, Meta kernel team , syzbot+09b7d050e4806540153d@syzkaller.appspotmail.com, Christoph Hellwig Subject: Re: [PATCH bpf v3] lib/buildid: use __kernel_read() for sleepable context Message-ID: <20251224-partner-eiszapfen-92104956caed@brauner> References: <20251222205859.3968077-1-shakeel.butt@linux.dev> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20251222205859.3968077-1-shakeel.butt@linux.dev> X-Rspamd-Queue-Id: 2D14418001E X-Stat-Signature: khsz5szfa5zgz5fo5nd3jww3yrwzdqhb X-Rspam-User: X-Rspamd-Server: rspam06 X-HE-Tag: 1766577725-91628 X-HE-Meta: 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 O/OQfU2l 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 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On Mon, Dec 22, 2025 at 12:58:59PM -0800, Shakeel Butt wrote: > For the sleepable context, convert freader to use __kernel_read() > instead of direct page cache access via read_cache_folio(). This > simplifies the faultable code path by using the standard kernel file > reading interface which handles all the complexity of reading file data. > > At the moment we are not changing the code for non-sleepable context > which uses filemap_get_folio() and only succeeds if the target folios > are already in memory and up-to-date. The reason is to keep the patch > simple and easier to backport to stable kernels. > > Syzbot repro does not crash the kernel anymore and the selftests run > successfully. > > In the follow up we will make __kernel_read() with IOCB_NOWAIT work for > non-sleepable contexts. In addition, I would like to replace the > secretmem check with a more generic approach and will add fstest for the > buildid code. > > Reported-by: syzbot+09b7d050e4806540153d@syzkaller.appspotmail.com > Closes: https://syzkaller.appspot.com/bug?extid=09b7d050e4806540153d > Fixes: ad41251c290d ("lib/buildid: implement sleepable build_id_parse() API") > Reviewed-by: Christoph Hellwig > Signed-off-by: Shakeel Butt > --- Reviewed-by: Christian Brauner