From patchwork Tue Apr 5 07:17:08 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Greg Kroah-Hartman X-Patchwork-Id: 557598 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id E5BEAC4332F for ; Tue, 5 Apr 2022 09:27:41 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1347523AbiDEJ1O (ORCPT ); Tue, 5 Apr 2022 05:27:14 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46800 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S243181AbiDEIuN (ORCPT ); Tue, 5 Apr 2022 04:50:13 -0400 Received: from dfw.source.kernel.org (dfw.source.kernel.org [139.178.84.217]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 7E807B6D25; Tue, 5 Apr 2022 01:38:23 -0700 (PDT) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by dfw.source.kernel.org (Postfix) with ESMTPS id D62D361538; Tue, 5 Apr 2022 08:37:52 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id E2951C385A0; Tue, 5 Apr 2022 08:37:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1649147872; bh=6s8M9Id1hc1E3XlOJxnCdy+HOfCUPObYt1vklKduNtc=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=XiLDTHlLmBlXDyOlnr5B8otE4DyIj2Baq9haEmabLKFaw/KSm+FaAvDWWj5lQ1zKn /RBoFFeFVNydRgpSiMogiNthXdBHhO0neMZyor4sS6kK6UMVf9zx+nZDoZrgE/F4cn CG1AJJNvmK2hW1xKfpHJxoQheRab/Y6Acv6Byg2k= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Charan Teja Kalla , Michal Hocko , Suren Baghdasaryan , Vlastimil Babka , David Rientjes , Nadav Amit , Andrew Morton , Linus Torvalds Subject: [PATCH 5.16 0115/1017] Revert "mm: madvise: skip unmapped vma holes passed to process_madvise" Date: Tue, 5 Apr 2022 09:17:08 +0200 Message-Id: <20220405070357.610639306@linuxfoundation.org> X-Mailer: git-send-email 2.35.1 In-Reply-To: <20220405070354.155796697@linuxfoundation.org> References: <20220405070354.155796697@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Charan Teja Kalla commit e6b0a7b357659c332231621e4315658d062c23ee upstream. This reverts commit 08095d6310a7 ("mm: madvise: skip unmapped vma holes passed to process_madvise") as process_madvise() fails to return the exact processed bytes in other cases too. As an example: if process_madvise() hits mlocked pages after processing some initial bytes passed in [start, end), it just returns EINVAL although some bytes are processed. Thus making an exception only for ENOMEM is partially fixing the problem of returning the proper advised bytes. Thus revert this patch and return proper bytes advised. Link: https://lkml.kernel.org/r/e73da1304a88b6a8a11907045117cccf4c2b8374.1648046642.git.quic_charante@quicinc.com Fixes: 08095d6310a7ce ("mm: madvise: skip unmapped vma holes passed to process_madvise") Signed-off-by: Charan Teja Kalla Acked-by: Michal Hocko Cc: Suren Baghdasaryan Cc: Vlastimil Babka Cc: David Rientjes Cc: Nadav Amit Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- mm/madvise.c | 9 +-------- 1 file changed, 1 insertion(+), 8 deletions(-) --- a/mm/madvise.c +++ b/mm/madvise.c @@ -1280,16 +1280,9 @@ SYSCALL_DEFINE5(process_madvise, int, pi while (iov_iter_count(&iter)) { iovec = iov_iter_iovec(&iter); - /* - * do_madvise returns ENOMEM if unmapped holes are present - * in the passed VMA. process_madvise() is expected to skip - * unmapped holes passed to it in the 'struct iovec' list - * and not fail because of them. Thus treat -ENOMEM return - * from do_madvise as valid and continue processing. - */ ret = do_madvise(mm, (unsigned long)iovec.iov_base, iovec.iov_len, behavior); - if (ret < 0 && ret != -ENOMEM) + if (ret < 0) break; iov_iter_advance(&iter, iovec.iov_len); }