From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from fhigh-a8-smtp.messagingengine.com (fhigh-a8-smtp.messagingengine.com [103.168.172.159]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 244D980603; Mon, 23 Sep 2024 21:50:36 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=103.168.172.159 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727128240; cv=none; b=cxw6JvF+b4INFSlMNrY9rQ0e7QEJKLjGzyXJ1R2p+3yLAfH98lcynTHXb2Oj44cSIGrR5dVdM7E1DVENjHQ3I/VJNMsGjmtCZf9if/kHqmExcGj4XiZcnDucj8TSG1G6Z485U/eoAPmTuyC/H1d+hKz+xQNG1WgRFcf+0P3bXHY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727128240; c=relaxed/simple; bh=jGoUda1eMDnVP6rY2rx+0rdFBSl5UCMK+VNb5V/HWbQ=; h=MIME-Version:Date:From:To:Cc:Message-Id:In-Reply-To:References: Subject:Content-Type; b=mg3mbaWk2vSb8qhUznUSCbva/6j4k0JIpBciwbvn5mKifzhUAfhH9qcrMZvThHeoU34MA+IywaIO95DX3HX+KSC7XFw1Wic/Olzlnr5gHGFx3rdv4GOEenQKQf8KX+f6/M5f75zF8+Cd5PFK2LTd7M6/XEbxp+W9J+XyzREP/dU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arndb.de; spf=pass smtp.mailfrom=arndb.de; dkim=pass (2048-bit key) header.d=arndb.de header.i=@arndb.de header.b=HZvEt5IP; dkim=pass (2048-bit key) header.d=messagingengine.com header.i=@messagingengine.com header.b=LTdAPKi9; arc=none smtp.client-ip=103.168.172.159 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arndb.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arndb.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=arndb.de header.i=@arndb.de header.b="HZvEt5IP"; dkim=pass (2048-bit key) header.d=messagingengine.com header.i=@messagingengine.com header.b="LTdAPKi9" Received: from phl-compute-10.internal (phl-compute-10.phl.internal [10.202.2.50]) by mailfhigh.phl.internal (Postfix) with ESMTP id 312FD11401A8; Mon, 23 Sep 2024 17:50:36 -0400 (EDT) Received: from phl-imap-11 ([10.202.2.101]) by phl-compute-10.internal (MEProxy); Mon, 23 Sep 2024 17:50:36 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=arndb.de; h=cc :cc:content-transfer-encoding:content-type:content-type:date :date:from:from:in-reply-to:in-reply-to:message-id:mime-version :references:reply-to:subject:subject:to:to; s=fm1; t=1727128236; x=1727214636; bh=O9Q/eImCaEWCrXoZrzE5xrq6F5YUMncTztU3Tb7lqN8=; b= HZvEt5IPNg2ONCbdFOIUYj1y5TP7QfFXn6dSsbLLHlKnIbcFf+utUjHwJqjuHuXO 18HORSZinuDOb7QKRQsauCYDcsl7M/lO7pviDzkucfJzLxF1lukaHkqTbxMIQ5hO G3iXDwn0c3zjdyXNooZ5cPABBvZvga8wN1TajU4LLB1X+QAiejGirdGa9+XCZ84K 3plNKso1qqrITtT25EFc/3NHewLVOYKMMqrAFaGB1iIHSd4l+le/KBlhu2MNmM3S InTcVAIxIyuwcGopqToG8zH4D4kzpAY79xlz2BxfLN8GDRNfuipSLUbrGG7V0vS1 SKVfXOpJ6ouZB7cIzgA0UQ== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:cc:content-transfer-encoding :content-type:content-type:date:date:feedback-id:feedback-id :from:from:in-reply-to:in-reply-to:message-id:mime-version :references:reply-to:subject:subject:to:to:x-me-proxy:x-me-proxy :x-me-sender:x-me-sender:x-sasl-enc; s=fm2; t=1727128236; x= 1727214636; bh=O9Q/eImCaEWCrXoZrzE5xrq6F5YUMncTztU3Tb7lqN8=; b=L TdAPKi9+eBrZKoZTjMK31/zAtWm9vVP0VWE3G6++eab6VAuHyYw2ylMea7CfrZqo cr5IubP4/pbRtrfrFukOnyHP3FCLKLaPW4d2DFu/M7424hj2YfpGoaceNLxuB0GM 5ci5L//lGHGBUA7D75pILD49fUoD0U43SalKQOLr8HgPCT7SyTEeaIo4OQaZzNDo mQOjvwrJ3mb2sRfnFNhLh7HluYxfeSLQLV9ArILvUXGatLQ7eXSJpt5tQzASJ8zn aoLbqEyQaO8rvCQuA8jkzLq+udRLapqjzEAAzPQRMPhBIAMhwhsdZ9VYc0TGx7f3 DHVbmt3xpHxIPJA5+SexQ== X-ME-Sender: X-ME-Proxy-Cause: gggruggvucftvghtrhhoucdtuddrgeeftddrvddttddgtdegucetufdoteggodetrfdotf fvucfrrhhofhhilhgvmecuhfgrshhtofgrihhlpdggtfgfnhhsuhgsshgtrhhisggvpdfu rfetoffkrfgpnffqhgenuceurghilhhouhhtmecufedttdenucesvcftvggtihhpihgvnh htshculddquddttddmnecujfgurhepofggfffhvfevkfgjfhfutgfgsehtjeertdertddt necuhfhrohhmpedftehrnhguuceuvghrghhmrghnnhdfuceorghrnhgusegrrhhnuggsrd guvgeqnecuggftrfgrthhtvghrnhephfdthfdvtdefhedukeetgefggffhjeeggeetfefg gfevudegudevledvkefhvdeinecuvehluhhsthgvrhfuihiivgeptdenucfrrghrrghmpe hmrghilhhfrhhomheprghrnhgusegrrhhnuggsrdguvgdpnhgspghrtghpthhtohepuddt pdhmohguvgepshhmthhpohhuthdprhgtphhtthhopehsuhhrvghnsgesghhoohhglhgvrd gtohhmpdhrtghpthhtohepmhhinhgthhgrnheskhgvrhhnvghlrdhorhhgpdhrtghpthht oheplhhinhhugidqmhhmsehkvhgrtghkrdhorhhgpdhrtghpthhtoheprghkphhmsehlih hnuhigqdhfohhunhgurghtihhonhdrohhrghdprhgtphhtthhopehshhgrkhgvvghlrdgs uhhttheslhhinhhugidruggvvhdprhgtphhtthhopehlihgrmhdrhhhofihlvghtthesoh hrrggtlhgvrdgtohhmpdhrtghpthhtoheplhhorhgvnhiiohdrshhtohgrkhgvshesohhr rggtlhgvrdgtohhmpdhrtghpthhtohepvhgsrggskhgrsehsuhhsvgdrtgiipdhrtghpth htoheplhhinhhugidqrghpihesvhhgvghrrdhkvghrnhgvlhdrohhrgh X-ME-Proxy: Feedback-ID: i56a14606:Fastmail Received: by mailuser.phl.internal (Postfix, from userid 501) id 928C12220071; Mon, 23 Sep 2024 17:50:35 -0400 (EDT) X-Mailer: MessagingEngine.com Webmail Interface Precedence: bulk X-Mailing-List: linux-api@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Date: Mon, 23 Sep 2024 21:49:43 +0000 From: "Arnd Bergmann" To: "Lorenzo Stoakes" , "Shakeel Butt" Cc: "Andrew Morton" , "Vlastimil Babka" , "Liam R. Howlett" , "Suren Baghdasaryan" , linux-api@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, "Minchan Kim" Message-Id: <337e4359-37e0-4ed7-894d-6c88b3498a42@app.fastmail.com> In-Reply-To: References: <077be0d59cb1047870a84c87c62e7b027af1c75d.1727106751.git.lorenzo.stoakes@oracle.com> Subject: Re: [PATCH 1/2] mm/madvise: introduce PR_MADV_SELF flag to process_madvise() Content-Type: text/plain Content-Transfer-Encoding: 7bit On Mon, Sep 23, 2024, at 19:34, Lorenzo Stoakes wrote: > On Mon, Sep 23, 2024 at 11:56:06AM GMT, Shakeel Butt wrote: > > + /* Require PTRACE_MODE_READ to avoid leaking ASLR metadata. */ > + mm = mm_access(task, PTRACE_MODE_READ_FSCREDS); > + if (IS_ERR_OR_NULL(mm)) { > + ret = IS_ERR(mm) ? PTR_ERR(mm) : -ESRCH; > + goto release_task; > + } Any chance we can fix mm_access() to not be able to return a NULL pointer and an error pointer? IS_ERR_OR_NULL() is usually an indication of a confusing API, and this is clearly one of them, given that only one of the callers actually wants the NULL value instead of -ESRCH. Arnd