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]) by smtp.lore.kernel.org (Postfix) with ESMTP id EAE34D18159 for ; Tue, 15 Oct 2024 00:00:18 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 783926B0082; Mon, 14 Oct 2024 20:00:18 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 733926B0083; Mon, 14 Oct 2024 20:00:18 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 621D26B0085; Mon, 14 Oct 2024 20:00:18 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0015.hostedemail.com [216.40.44.15]) by kanga.kvack.org (Postfix) with ESMTP id 42D006B0082 for ; Mon, 14 Oct 2024 20:00:18 -0400 (EDT) Received: from smtpin01.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay06.hostedemail.com (Postfix) with ESMTP id 9B98EAC0BC for ; Tue, 15 Oct 2024 00:00:01 +0000 (UTC) X-FDA: 82673879022.01.C50D2E3 Received: from out-181.mta1.migadu.com (out-181.mta1.migadu.com [95.215.58.181]) by imf16.hostedemail.com (Postfix) with ESMTP id 01725180015 for ; Tue, 15 Oct 2024 00:00:07 +0000 (UTC) Authentication-Results: imf16.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=TslArgC7; spf=pass (imf16.hostedemail.com: domain of shakeel.butt@linux.dev designates 95.215.58.181 as permitted sender) smtp.mailfrom=shakeel.butt@linux.dev; dmarc=pass (policy=none) header.from=linux.dev ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1728950341; a=rsa-sha256; cv=none; b=I5T9L8Qg7CiUiWlNRCcIYeBCa5IpUSjRqcQPDDRsgEV1MPXAtHTrqCnoeLaezU2ua8qKSU XkQ/X7ArBoRGJnQ3p78pxCnIwdmsEZnHaWkJuBe2+RFhzTalbjMzBVFpa3cy3Cmf2cRe2U ZqxKc5Vrc9rSG5eD1Jo8PH4YvYdpPLc= ARC-Authentication-Results: i=1; imf16.hostedemail.com; dkim=pass header.d=linux.dev header.s=key1 header.b=TslArgC7; spf=pass (imf16.hostedemail.com: domain of shakeel.butt@linux.dev designates 95.215.58.181 as permitted sender) smtp.mailfrom=shakeel.butt@linux.dev; dmarc=pass (policy=none) header.from=linux.dev ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1728950341; 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=vh3jiunjWIwsOuFiNu4hKpvARjvNFqPFZ+Dwxoe0LFg=; b=XcSRMt8HLHhmyDbieuoEd6hyhrw14KzkGETHVZpGWjGAI4bQnho3ywxfUC4ufptjD74WRN K5//HcVhAvUEUcgwBxIL1kxcFViMbGgNafnKpExuTPWH3MMCkr+BKcduOzsfUztmM7hodR McIp2cgZLnN9UNsuR6Rmhnva2ZKDBGA= Date: Mon, 14 Oct 2024 17:00:08 -0700 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1728950412; 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: in-reply-to:in-reply-to:references:references; bh=vh3jiunjWIwsOuFiNu4hKpvARjvNFqPFZ+Dwxoe0LFg=; b=TslArgC7lZohDr+TNPyhLdypH0ePq5iw1b4E7wfSig4Vl37bf5nG7rABIy9+6srd8pj65f 0kklSPI/wFWx+MRVNVlcqBnajG57g0ninSKqeUSb6OXpZtoqdCDaIQ2bVwOXO6MHKXNJpo fp9u3PUw4JZMTMGJOOFEb0nfNnk6JME= X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Shakeel Butt To: Andrii Nakryiko Cc: bpf@vger.kernel.org, ast@kernel.org, daniel@iogearbox.net, martin.lau@kernel.org, linux-mm@kvack.org, linux-perf-users@vger.kernel.org, linux-fsdevel@vger.kernel.org, Yi Lai Subject: Re: [PATCH bpf] lib/buildid: handle memfd_secret() files in build_id_parse() Message-ID: References: <20241014235631.1229438-1-andrii@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20241014235631.1229438-1-andrii@kernel.org> X-Migadu-Flow: FLOW_OUT X-Stat-Signature: u3b4jit6rshod1i9dx9h9czkhjixruge X-Rspamd-Queue-Id: 01725180015 X-Rspam-User: X-Rspamd-Server: rspam10 X-HE-Tag: 1728950407-649916 X-HE-Meta: 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 b/KBrqka lp2TU/iWPd/55P8b7tMwYFJ7ea4W/YxfECFXpZdiotKVP+U0OKjH9322AF+8YKtdVxz0wHWPnEqS2zQFlDd4iABMyuZ/59LGTlArT4RZs4CKA0+sJTfzU3SjZEn/rtxAQr2UKiH4jFpH2KyPwV4G5Qg1C91tl+9UWpZt3Uu1jgTzCX0nVFQy5o9hDUl6crxvFZljX0W5BIAe7ixuf6az+/SpzERWKIKoORY8d/8YLwHLTvHc= 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, Oct 14, 2024 at 04:56:31PM GMT, Andrii Nakryiko wrote: > From memfd_secret(2) manpage: > > The memory areas backing the file created with memfd_secret(2) are > visible only to the processes that have access to the file descriptor. > The memory region is removed from the kernel page tables and only the > page tables of the processes holding the file descriptor map the > corresponding physical memory. (Thus, the pages in the region can't be > accessed by the kernel itself, so that, for example, pointers to the > region can't be passed to system calls.) > > We need to handle this special case gracefully in build ID fetching > code. Return -EACCESS whenever secretmem file is passed to build_id_parse() > family of APIs. Original report and repro can be found in [0]. > > [0] https://lore.kernel.org/bpf/ZwyG8Uro%2FSyTXAni@ly-workstation/ > > Reported-by: Yi Lai > Suggested-by: Shakeel Butt > Fixes: de3ec364c3c3 ("lib/buildid: add single folio-based file reader abstraction") > Signed-off-by: Andrii Nakryiko Acked-by: Shakeel Butt