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=-6.9 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH, MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS 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 1B09BC33CB2 for ; Thu, 30 Jan 2020 02:24:56 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id C71102070E for ; Thu, 30 Jan 2020 02:24:55 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="SbzWTHzD" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C71102070E Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 4D3736B02CB; Wed, 29 Jan 2020 21:24:55 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 484706B02CC; Wed, 29 Jan 2020 21:24:55 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 399B66B02CD; Wed, 29 Jan 2020 21:24:55 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0196.hostedemail.com [216.40.44.196]) by kanga.kvack.org (Postfix) with ESMTP id 23F126B02CB for ; Wed, 29 Jan 2020 21:24:55 -0500 (EST) Received: from smtpin18.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay05.hostedemail.com (Postfix) with ESMTP id B72A3181AEF0B for ; Thu, 30 Jan 2020 02:24:54 +0000 (UTC) X-FDA: 76432707708.18.name24_dbcf7e26e40d X-HE-Tag: name24_dbcf7e26e40d X-Filterd-Recvd-Size: 9238 Received: from us-smtp-delivery-1.mimecast.com (us-smtp-2.mimecast.com [207.211.31.81]) by imf02.hostedemail.com (Postfix) with ESMTP for ; Thu, 30 Jan 2020 02:24:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1580351093; 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: content-transfer-encoding:content-transfer-encoding; bh=hlume1Bkov9GcHxw+RCAA4JqBi7KM0TW+o4ETBlwdwc=; b=SbzWTHzDXNUc3+1JllY2LduwaHw2pYQjqm5Lrj0jCUb8oaCTTa+ZVlzgDWDWzNs/nEXmzw HPEtJ1qYERgaysK4mh1/CvSW8GAvHkLH46DV0HhOeb/OSzOM4l6a8s4pfL9yltq1ETPcE3 IiC7wMD4ELRp9IeQ/rKSxgq6p/LlPHk= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-161-Fk-tHHypO32GHQFQy55GBw-1; Wed, 29 Jan 2020 21:24:52 -0500 Received: from smtp.corp.redhat.com (int-mx07.intmail.prod.int.phx2.redhat.com [10.5.11.22]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 6252D13E2; Thu, 30 Jan 2020 02:24:51 +0000 (UTC) Received: from localhost.localdomain.com (vpn2-54-25.bne.redhat.com [10.64.54.25]) by smtp.corp.redhat.com (Postfix) with ESMTP id 29B7710027BA; Thu, 30 Jan 2020 02:24:48 +0000 (UTC) From: Gavin Shan To: linux-mm@kvack.org Cc: aarcange@redhat.com, akpm@linux-foundation.org, mhocko@suse.com Subject: [PATCH 1/3] mm: Rework {enabled,defrag}_store() Date: Thu, 30 Jan 2020 13:24:39 +1100 Message-Id: <20200130022441.95488-2-gshan@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.84 on 10.5.11.22 X-MC-Unique: Fk-tHHypO32GHQFQy55GBw-1 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: quoted-printable 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: The suffix of the input buffer is truncated in {enabled,defrag}_store(). With that, the illegal settings can be accepted, as the following example shows. # cat /sys/kernel/mm/transparent_hugepage/enabled always [madvise] never # echo neveroff > /sys/kernel/mm/transparent_hugepage/enabled # cat /sys/kernel/mm/transparent_hugepage/enabled always madvise [never] This reworks {enabled,defrag}_store() to fix the issue and make the code a bit more extendible. With this applied, the illegal settings will be rejected: # echo neveroff > /sys/kernel/mm/transparent_hugepage/enabled sh: write error: Invalid argument Signed-off-by: Gavin Shan --- mm/huge_memory.c | 114 ++++++++++++++++++++++++++--------------------- 1 file changed, 62 insertions(+), 52 deletions(-) diff --git a/mm/huge_memory.c b/mm/huge_memory.c index a88093213674..7bd573f1631d 100644 --- a/mm/huge_memory.c +++ b/mm/huge_memory.c @@ -160,6 +160,15 @@ static struct shrinker huge_zero_page_shrinker =3D { }; =20 #ifdef CONFIG_SYSFS +static const char * const enabled_strings[] =3D { +=09"always", "madvise", "never" +}; +static unsigned int enabled_bits[] =3D { +=09TRANSPARENT_HUGEPAGE_FLAG, +=09TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG, +=09UINT_MAX +}; + static ssize_t enabled_show(struct kobject *kobj, =09=09=09 struct kobj_attribute *attr, char *buf) { @@ -175,29 +184,29 @@ static ssize_t enabled_store(struct kobject *kobj, =09=09=09 struct kobj_attribute *attr, =09=09=09 const char *buf, size_t count) { -=09ssize_t ret =3D count; - -=09if (!memcmp("always", buf, -=09=09 min(sizeof("always")-1, count))) { -=09=09clear_bit(TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG, &transparent_hugepage_= flags); -=09=09set_bit(TRANSPARENT_HUGEPAGE_FLAG, &transparent_hugepage_flags); -=09} else if (!memcmp("madvise", buf, -=09=09=09 min(sizeof("madvise")-1, count))) { -=09=09clear_bit(TRANSPARENT_HUGEPAGE_FLAG, &transparent_hugepage_flags); -=09=09set_bit(TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG, &transparent_hugepage_fl= ags); -=09} else if (!memcmp("never", buf, -=09=09=09 min(sizeof("never")-1, count))) { -=09=09clear_bit(TRANSPARENT_HUGEPAGE_FLAG, &transparent_hugepage_flags); -=09=09clear_bit(TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG, &transparent_hugepage_= flags); -=09} else -=09=09ret =3D -EINVAL; +=09int i, ret; =20 -=09if (ret > 0) { -=09=09int err =3D start_stop_khugepaged(); -=09=09if (err) -=09=09=09ret =3D err; +=09for (i =3D 0; i < ARRAY_SIZE(enabled_strings); i++) { +=09=09if ((count - 1) =3D=3D strlen(enabled_strings[i]) && +=09=09 !memcmp(buf, enabled_strings[i], count - 1)) +=09=09=09break; =09} -=09return ret; + +=09if (i >=3D ARRAY_SIZE(enabled_strings)) +=09=09return -EINVAL; + +=09clear_bit(TRANSPARENT_HUGEPAGE_FLAG, +=09=09 &transparent_hugepage_flags); +=09clear_bit(TRANSPARENT_HUGEPAGE_REQ_MADV_FLAG, +=09=09 &transparent_hugepage_flags); +=09if (enabled_bits[i] !=3D UINT_MAX) +=09=09set_bit(enabled_bits[i], &transparent_hugepage_flags); + +=09ret =3D start_stop_khugepaged(); +=09if (ret) +=09=09return ret; + +=09return count; } static struct kobj_attribute enabled_attr =3D =09__ATTR(enabled, 0644, enabled_show, enabled_store); @@ -232,6 +241,17 @@ ssize_t single_hugepage_flag_store(struct kobject *kob= j, =09return count; } =20 +static const char * const defrag_strings[] =3D { +=09"always", "defer+madvise", "defer", "madvise", "never" +}; +static unsigned int defrag_bits[] =3D { +=09TRANSPARENT_HUGEPAGE_DEFRAG_DIRECT_FLAG, +=09TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_OR_MADV_FLAG, +=09TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_FLAG, +=09TRANSPARENT_HUGEPAGE_DEFRAG_REQ_MADV_FLAG, +=09UINT_MAX +}; + static ssize_t defrag_show(struct kobject *kobj, =09=09=09 struct kobj_attribute *attr, char *buf) { @@ -250,39 +270,29 @@ static ssize_t defrag_store(struct kobject *kobj, =09=09=09 struct kobj_attribute *attr, =09=09=09 const char *buf, size_t count) { -=09if (!memcmp("always", buf, -=09=09 min(sizeof("always")-1, count))) { -=09=09clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_FLAG, &transparent_huge= page_flags); -=09=09clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_OR_MADV_FLAG, &transpar= ent_hugepage_flags); -=09=09clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_REQ_MADV_FLAG, &transparent_hu= gepage_flags); -=09=09set_bit(TRANSPARENT_HUGEPAGE_DEFRAG_DIRECT_FLAG, &transparent_hugepa= ge_flags); -=09} else if (!memcmp("defer+madvise", buf, -=09=09 min(sizeof("defer+madvise")-1, count))) { -=09=09clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_DIRECT_FLAG, &transparent_huge= page_flags); -=09=09clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_FLAG, &transparent_huge= page_flags); -=09=09clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_REQ_MADV_FLAG, &transparent_hu= gepage_flags); -=09=09set_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_OR_MADV_FLAG, &transparen= t_hugepage_flags); -=09} else if (!memcmp("defer", buf, -=09=09 min(sizeof("defer")-1, count))) { -=09=09clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_DIRECT_FLAG, &transparent_huge= page_flags); -=09=09clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_OR_MADV_FLAG, &transpar= ent_hugepage_flags); -=09=09clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_REQ_MADV_FLAG, &transparent_hu= gepage_flags); -=09=09set_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_FLAG, &transparent_hugepa= ge_flags); -=09} else if (!memcmp("madvise", buf, -=09=09=09 min(sizeof("madvise")-1, count))) { -=09=09clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_DIRECT_FLAG, &transparent_huge= page_flags); -=09=09clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_FLAG, &transparent_huge= page_flags); -=09=09clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_OR_MADV_FLAG, &transpar= ent_hugepage_flags); -=09=09set_bit(TRANSPARENT_HUGEPAGE_DEFRAG_REQ_MADV_FLAG, &transparent_huge= page_flags); -=09} else if (!memcmp("never", buf, -=09=09=09 min(sizeof("never")-1, count))) { -=09=09clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_DIRECT_FLAG, &transparent_huge= page_flags); -=09=09clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_FLAG, &transparent_huge= page_flags); -=09=09clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_OR_MADV_FLAG, &transpar= ent_hugepage_flags); -=09=09clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_REQ_MADV_FLAG, &transparent_hu= gepage_flags); -=09} else +=09int i; + +=09for (i =3D 0; i < ARRAY_SIZE(defrag_strings); i++) { +=09=09if ((count - 1) =3D=3D strlen(defrag_strings[i]) && +=09=09 !memcmp(buf, defrag_strings[i], count - 1)) +=09=09=09break; +=09} + +=09if (i >=3D ARRAY_SIZE(defrag_strings)) =09=09return -EINVAL; =20 +=09clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_DIRECT_FLAG, +=09=09 &transparent_hugepage_flags); +=09clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_FLAG, +=09=09 &transparent_hugepage_flags); +=09clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_KSWAPD_OR_MADV_FLAG, +=09=09 &transparent_hugepage_flags); +=09clear_bit(TRANSPARENT_HUGEPAGE_DEFRAG_REQ_MADV_FLAG, +=09=09 &transparent_hugepage_flags); + +=09if (defrag_bits[i] !=3D UINT_MAX) +=09=09set_bit(defrag_bits[i], &transparent_hugepage_flags); + =09return count; } static struct kobj_attribute defrag_attr =3D --=20 2.23.0