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 X-Spam-Level: X-Spam-Status: No, score=-15.9 required=3.0 tests=DKIMWL_WL_MED,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1, USER_IN_DEF_DKIM_WL autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1C579C33C9E for ; Fri, 17 Jan 2020 22:11:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id CEB4321D56 for ; Fri, 17 Jan 2020 22:11:51 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="IY7dG2oF" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729968AbgAQWLv (ORCPT ); Fri, 17 Jan 2020 17:11:51 -0500 Received: from mail-pf1-f195.google.com ([209.85.210.195]:38738 "EHLO mail-pf1-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729246AbgAQWLu (ORCPT ); Fri, 17 Jan 2020 17:11:50 -0500 Received: by mail-pf1-f195.google.com with SMTP id x185so12559176pfc.5 for ; Fri, 17 Jan 2020 14:11:50 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=date:from:to:cc:subject:in-reply-to:message-id:references :user-agent:mime-version; bh=I07pR0oCHYZ+OosxxFEWPv5kDJlwMJ/Csumm0eUVygc=; b=IY7dG2oFgZVtqoBqrQQrRCWrDUSV1LC/NSDgr//4rHlhS6Vp+V2u9iTNfTll0hhDN0 DdXnXLiBhzLElgcNysVIBSjuv1OZHnhvzacjA3ME7q7snNAM7nhpF2/eLxykhfZW9nxZ p9bT7Qf/wSA3MOfjBFHK00dxMdnX6IDsCoC1fY5U2jLU64alEpoY1r9mUrfYgG3Utqsq xDxk6JCxmxEFka1Jf6072QxB24IglEagJ24t0HdToxnLnNCEuF6zAoMUQaNJvfDrgwaf 5AjBAIM9OAWoOBELnt7qJa4Hs15KW19nZkxmsmx4U3bj7f18zSMFOyPOyJctM0TiPkZs pkOg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:in-reply-to:message-id :references:user-agent:mime-version; bh=I07pR0oCHYZ+OosxxFEWPv5kDJlwMJ/Csumm0eUVygc=; b=CJAfkgeCAeQMsCz4f5dvE6ilVa4LSLRng5W1jahkMDiXSAeGgXpT3lkiITJZF1kifT 03jzP8mt5POxoi7j6uwxXfKIRz4HpKIuO1KzBqnfpI9jSdeaLqzbJkg2Dnepii8548CF xCN0oUtrUBdkz4L5dMRn5G9bu7EjnHrksPyWEs3PnXq9pvlbQj5S7o42uT+gO1G9bLqm h046dWbesVfZH2bOdE0llJQrem1wyTjHlBQtbqwOmkl+YTS2bLIf6kxlmlr/aPcq9lOv wrpLA3dkGrZuPJc2NfBZUXspu1gxQDoFuPSmfe8FR34F0vJfhkvwODQYGpRmT3cv5NSv zxqg== X-Gm-Message-State: APjAAAVjmhQdijiSBcBEJU/QeDB/A0K8daE8C13AGzFplbbxIB9tVbU+ RiESXHIywo5o9EeX3h6MU7OhKkCkDto= X-Google-Smtp-Source: APXvYqzl5ui39E2Jhw94MkIfpeo/6fENDkaM2NcZLxDoCcu8TbV6QLo/CC4vzcYcHtJWW6l4jIGhIA== X-Received: by 2002:a63:d62:: with SMTP id 34mr49600714pgn.268.1579299109485; Fri, 17 Jan 2020 14:11:49 -0800 (PST) Received: from [2620:15c:17:3:3a5:23a7:5e32:4598] ([2620:15c:17:3:3a5:23a7:5e32:4598]) by smtp.gmail.com with ESMTPSA id a195sm30899088pfa.120.2020.01.17.14.11.48 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 17 Jan 2020 14:11:48 -0800 (PST) Date: Fri, 17 Jan 2020 14:11:48 -0800 (PST) From: David Rientjes X-X-Sender: rientjes@chino.kir.corp.google.com To: Andrew Morton cc: Vlastimil Babka , Mel Gorman , linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: [patch v2] mm, thp: fix defrag setting if newline is not used In-Reply-To: Message-ID: References: <20200116191609.3972fd5301cf364a27381923@linux-foundation.org> <025511aa-4721-2edb-d658-78d6368a9101@suse.cz> User-Agent: Alpine 2.21 (DEB 202 2017-01-01) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org If thp defrag setting "defer" is used and a newline is *not* used when writing to the sysfs file, this is interpreted as the "defer+madvise" option. This is because we do prefix matching and if five characters are written without a newline, the current code ends up comparing to the first five bytes of the "defer+madvise" option and using that instead. Use the more appropriate sysfs_streq() that handles the trailing newline for us. Since this doubles as a nice cleanup, do it in enabled_store() as well. Fixes: 21440d7eb904 ("mm, thp: add new defer+madvise defrag option") Cc: Vlastimil Babka Cc: Mel Gorman Suggested-by: Andrew Morton Signed-off-by: David Rientjes --- Latest 5.5-rc6 doesn't boot for me, something to be debugged separately, so this was tested on 5.4. No changes in this area, however, between the two kernels. mm/huge_memory.c | 24 ++++++++---------------- 1 file changed, 8 insertions(+), 16 deletions(-) diff --git a/mm/huge_memory.c b/mm/huge_memory.c index 13cc93785006..1c61dea937bc 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -177,16 +177,13 @@ static ssize_t enabled_store(struct kobject *kobj, { ssize_t ret = count; - if (!memcmp("always", buf, - min(sizeof("always")-1, count))) { + if (sysfs_streq(buf, "always")) { clear_bit(TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG, &transparent_hugepage_flags); set_bit(TRANSPARENT_HUGEPAGE_FLAG, &transparent_hugepage_flags); - } else if (!memcmp("madvise", buf, - min(sizeof("madvise")-1, count))) { + } else if (sysfs_streq(buf, "madvise")) { clear_bit(TRANSPARENT_HUGEPAGE_FLAG, &transparent_hugepage_flags); set_bit(TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG, &transparent_hugepage_flags); - } else if (!memcmp("never", buf, - min(sizeof("never")-1, count))) { + } else if (sysfs_streq(buf, "never")) { clear_bit(TRANSPARENT_HUGEPAGE_FLAG, &transparent_hugepage_flags); clear_bit(TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG, &transparent_hugepage_flags); } else @@ -250,32 +247,27 @@ static ssize_t defrag_store(struct kobject *kobj, struct kobj_attribute *attr, const char *buf, size_t count) { - if (!memcmp("always", buf, - min(sizeof("always")-1, count))) { + if (sysfs_streq(buf, "always")) { clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_FLAG, &transparent_hugepage_flags); clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_OR_MADV_FLAG, &transparent_hugepage_flags); clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_REQ_MADV_FLAG, &transparent_hugepage_flags); set_bit(TRANSPARENT_HUGEPAGE_DEFRAG_DIRECT_FLAG, &transparent_hugepage_flags); - } else if (!memcmp("defer+madvise", buf, - min(sizeof("defer+madvise")-1, count))) { + } else if (sysfs_streq(buf, "defer+madvise")) { clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_DIRECT_FLAG, &transparent_hugepage_flags); clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_FLAG, &transparent_hugepage_flags); clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_REQ_MADV_FLAG, &transparent_hugepage_flags); set_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_OR_MADV_FLAG, &transparent_hugepage_flags); - } else if (!memcmp("defer", buf, - min(sizeof("defer")-1, count))) { + } else if (sysfs_streq(buf, "defer")) { clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_DIRECT_FLAG, &transparent_hugepage_flags); clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_OR_MADV_FLAG, &transparent_hugepage_flags); clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_REQ_MADV_FLAG, &transparent_hugepage_flags); set_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_FLAG, &transparent_hugepage_flags); - } else if (!memcmp("madvise", buf, - min(sizeof("madvise")-1, count))) { + } else if (sysfs_streq(buf, "madvise")) { clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_DIRECT_FLAG, &transparent_hugepage_flags); clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_FLAG, &transparent_hugepage_flags); clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_OR_MADV_FLAG, &transparent_hugepage_flags); set_bit(TRANSPARENT_HUGEPAGE_DEFRAG_REQ_MADV_FLAG, &transparent_hugepage_flags); - } else if (!memcmp("never", buf, - min(sizeof("never")-1, count))) { + } else if (sysfs_streq(buf, "never")) { clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_DIRECT_FLAG, &transparent_hugepage_flags); clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_FLAG, &transparent_hugepage_flags); clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_OR_MADV_FLAG, &transparent_hugepage_flags);