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 1DB3AC7EE23 for ; Thu, 11 May 2023 13:19:43 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id ACE9D6B007B; Thu, 11 May 2023 09:19:42 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id A58396B007D; Thu, 11 May 2023 09:19:42 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 921216B007E; Thu, 11 May 2023 09:19:42 -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 800AE6B007B for ; Thu, 11 May 2023 09:19:42 -0400 (EDT) Received: from smtpin04.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay07.hostedemail.com (Postfix) with ESMTP id 40A4916097F for ; Thu, 11 May 2023 13:19:42 +0000 (UTC) X-FDA: 80778031404.04.1E0DF0C Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by imf01.hostedemail.com (Postfix) with ESMTP id 42BB240122 for ; Thu, 11 May 2023 13:14:38 +0000 (UTC) Authentication-Results: imf01.hostedemail.com; dkim=none; dmarc=pass (policy=none) header.from=arm.com; spf=pass (imf01.hostedemail.com: domain of ryan.roberts@arm.com designates 217.140.110.172 as permitted sender) smtp.mailfrom=ryan.roberts@arm.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1683810879; 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:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=fueJieWX8MOdPaZoFRgtP9zAyqmznbriY8mnCseFeIc=; b=e1Pet8bfE5g7Y9QRQEAgBhlIiTzZjyOovvcbxeVv5CGgcyghvtI8yD9mNwbLhfaVMoPCLZ VT+y8fJnoivVQdOJMGRKY/OSU1mGuEjv54/qzUV9dpTjEGyh1eaNOwbakShJB7Ws25jP9l Npe76M487RJg2Fx65RdwgUfVnCBtqSE= ARC-Authentication-Results: i=1; imf01.hostedemail.com; dkim=none; dmarc=pass (policy=none) header.from=arm.com; spf=pass (imf01.hostedemail.com: domain of ryan.roberts@arm.com designates 217.140.110.172 as permitted sender) smtp.mailfrom=ryan.roberts@arm.com ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1683810879; a=rsa-sha256; cv=none; b=wvAwkhJ47S1XbWNWM6faUfGqutIDxdhYit6RvDwsN0SivHM8yssw9XtK9zZwCTHtvC/Hzn eAEGK3Pyc4LbCLA26noGW9wcdUfWbDBJu91Hc0XrINJwcMgPDML8rtTZdQUxscVaE5YUre 4qqMVgCu7GNExomagK6w14iA0vOGnj8= Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id BE07C113E; Thu, 11 May 2023 06:15:22 -0700 (PDT) Received: from [10.1.34.59] (C02Z41KALVDN.cambridge.arm.com [10.1.34.59]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 24A423F5A1; Thu, 11 May 2023 06:14:37 -0700 (PDT) Message-ID: <27f2ad91-2507-a58c-2fb7-211c7f90bbdb@arm.com> Date: Thu, 11 May 2023 14:14:35 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:102.0) Gecko/20100101 Thunderbird/102.10.1 Subject: Re: [PATCH v1 3/5] mm: Fix failure to unmap pte on highmem systems To: Andrew Morton , "Matthew Wilcox (Oracle)" , "Kirill A. Shutemov" , SeongJae Park Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, damon@lists.linux.dev References: <20230511125848.78621-1-ryan.roberts@arm.com> <20230511125848.78621-4-ryan.roberts@arm.com> From: Ryan Roberts In-Reply-To: <20230511125848.78621-4-ryan.roberts@arm.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Stat-Signature: y4zrq6in3qx37a4f3thg56xr8ftat8rm X-Rspam-User: X-Rspamd-Queue-Id: 42BB240122 X-Rspamd-Server: rspam07 X-HE-Tag: 1683810878-982576 X-HE-Meta: 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 DmO+Ropl 9Oy8KElauY/A3n2/lJl4wkw5Co3elZf64U5VR4ieMY0oyGZQs5T8c82GOeqf8KPhLdfdDYmKhDBqF8FPnXDxEE5PBsrAjFL1par8axfw0fEu7r7Np+Tl1XWHdQhYd5NdM4sIkkUVgeIx9pB77Yj5t/SWOY9dUuYE5fx5q 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: My appologies for the noise: A blank line between Cc and Subject has broken the subject and grouping in lore. Please Ignore this, I will resend. On 11/05/2023 13:58, Ryan Roberts wrote: > The loser of a race to service a pte for a device private entry in the > swap path previously unlocked the ptl, but failed to unmap the pte. This > only affects highmem systems since unmapping a pte is a noop on > non-highmem systems. > > Fixes: 16ce101db85d ("mm/memory.c: fix race when faulting a device private page") > Signed-off-by: Ryan Roberts > --- > mm/memory.c | 6 ++---- > 1 file changed, 2 insertions(+), 4 deletions(-) > > diff --git a/mm/memory.c b/mm/memory.c > index f69fbc251198..ed429e20a1bb 100644 > --- a/mm/memory.c > +++ b/mm/memory.c > @@ -3728,10 +3728,8 @@ vm_fault_t do_swap_page(struct vm_fault *vmf) > vmf->page = pfn_swap_entry_to_page(entry); > vmf->pte = pte_offset_map_lock(vma->vm_mm, vmf->pmd, > vmf->address, &vmf->ptl); > - if (unlikely(!pte_same(*vmf->pte, vmf->orig_pte))) { > - spin_unlock(vmf->ptl); > - goto out; > - } > + if (unlikely(!pte_same(*vmf->pte, vmf->orig_pte))) > + goto unlock; > > /* > * Get a page reference while we know the page can't be