From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1163205AbbKTQmj (ORCPT ); Fri, 20 Nov 2015 11:42:39 -0500 Received: from mail-lf0-f68.google.com ([209.85.215.68]:35365 "EHLO mail-lf0-f68.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1163120AbbKTQmf (ORCPT ); Fri, 20 Nov 2015 11:42:35 -0500 From: Piotr Kwapulinski To: akpm@linux-foundation.org Cc: mhocko@suse.com, oleg@redhat.com, cmetcalf@ezchip.com, mszeredi@suse.cz, viro@zeniv.linux.org.uk, dave@stgolabs.net, kirill.shutemov@linux.intel.com, n-horiguchi@ah.jp.nec.com, aarcange@redhat.com, iamjoonsoo.kim@lge.com, jack@suse.cz, xiexiuqi@huawei.com, vbabka@suse.cz, Vineet.Gupta1@synopsys.com, riel@redhat.com, gang.chen.5i5j@gmail.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, Piotr Kwapulinski Subject: [PATCH v2 2/2] mm/mmap.c: remove incorrect MAP_FIXED flag comparison from mmap_region Date: Fri, 20 Nov 2015 17:42:14 +0100 Message-Id: <1448037734-4734-1-git-send-email-kwapulinski.piotr@gmail.com> X-Mailer: git-send-email 2.6.2 In-Reply-To: <20151118162939.GA1842@home.local> References: <20151118162939.GA1842@home.local> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org The following flag comparison in mmap_region makes no sense: if (!(vm_flags & MAP_FIXED)) return -ENOMEM; The condition is always false and thus the above "return -ENOMEM" is never executed. The vm_flags must not be compared with MAP_FIXED flag. The vm_flags may only be compared with VM_* flags. MAP_FIXED has the same value as VM_MAYREAD. It has no user visible effect. Remove the code that makes no sense. Signed-off-by: Piotr Kwapulinski --- I made a mistake in a changelog in a previous version of this patch. I'm Sorry for the confusion. This patch may be considered to be applied only in case the patch "[PATCH v2 1/2] mm: fix incorrect behavior when process virtual address space limit is exceeded" is not going to be accepted. mm/mmap.c | 3 --- 1 file changed, 3 deletions(-) diff --git a/mm/mmap.c b/mm/mmap.c index 2ce04a6..42a8259 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -1551,9 +1551,6 @@ unsigned long mmap_region(struct file *file, unsigned long addr, * MAP_FIXED may remove pages of mappings that intersects with * requested mapping. Account for the pages it would unmap. */ - if (!(vm_flags & MAP_FIXED)) - return -ENOMEM; - nr_pages = count_vma_pages_range(mm, addr, addr + len); if (!may_expand_vm(mm, (len >> PAGE_SHIFT) - nr_pages)) -- 2.6.2 From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-lf0-f46.google.com (mail-lf0-f46.google.com [209.85.215.46]) by kanga.kvack.org (Postfix) with ESMTP id 27ED76B0253 for ; Fri, 20 Nov 2015 11:42:35 -0500 (EST) Received: by lfs39 with SMTP id 39so72700257lfs.3 for ; Fri, 20 Nov 2015 08:42:34 -0800 (PST) Received: from mail-lf0-x244.google.com (mail-lf0-x244.google.com. [2a00:1450:4010:c07::244]) by mx.google.com with ESMTPS id q21si224143lfq.128.2015.11.20.08.42.33 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Fri, 20 Nov 2015 08:42:33 -0800 (PST) Received: by lfu94 with SMTP id 94so6670625lfu.1 for ; Fri, 20 Nov 2015 08:42:33 -0800 (PST) From: Piotr Kwapulinski Subject: [PATCH v2 2/2] mm/mmap.c: remove incorrect MAP_FIXED flag comparison from mmap_region Date: Fri, 20 Nov 2015 17:42:14 +0100 Message-Id: <1448037734-4734-1-git-send-email-kwapulinski.piotr@gmail.com> In-Reply-To: <20151118162939.GA1842@home.local> References: <20151118162939.GA1842@home.local> Sender: owner-linux-mm@kvack.org List-ID: To: akpm@linux-foundation.org Cc: mhocko@suse.com, oleg@redhat.com, cmetcalf@ezchip.com, mszeredi@suse.cz, viro@zeniv.linux.org.uk, dave@stgolabs.net, kirill.shutemov@linux.intel.com, n-horiguchi@ah.jp.nec.com, aarcange@redhat.com, iamjoonsoo.kim@lge.com, jack@suse.cz, xiexiuqi@huawei.com, vbabka@suse.cz, Vineet.Gupta1@synopsys.com, riel@redhat.com, gang.chen.5i5j@gmail.com, linux-kernel@vger.kernel.org, linux-mm@kvack.org, Piotr Kwapulinski The following flag comparison in mmap_region makes no sense: if (!(vm_flags & MAP_FIXED)) return -ENOMEM; The condition is always false and thus the above "return -ENOMEM" is never executed. The vm_flags must not be compared with MAP_FIXED flag. The vm_flags may only be compared with VM_* flags. MAP_FIXED has the same value as VM_MAYREAD. It has no user visible effect. Remove the code that makes no sense. Signed-off-by: Piotr Kwapulinski --- I made a mistake in a changelog in a previous version of this patch. I'm Sorry for the confusion. This patch may be considered to be applied only in case the patch "[PATCH v2 1/2] mm: fix incorrect behavior when process virtual address space limit is exceeded" is not going to be accepted. mm/mmap.c | 3 --- 1 file changed, 3 deletions(-) diff --git a/mm/mmap.c b/mm/mmap.c index 2ce04a6..42a8259 100644 --- a/mm/mmap.c +++ b/mm/mmap.c @@ -1551,9 +1551,6 @@ unsigned long mmap_region(struct file *file, unsigned long addr, * MAP_FIXED may remove pages of mappings that intersects with * requested mapping. Account for the pages it would unmap. */ - if (!(vm_flags & MAP_FIXED)) - return -ENOMEM; - nr_pages = count_vma_pages_range(mm, addr, addr + len); if (!may_expand_vm(mm, (len >> PAGE_SHIFT) - nr_pages)) -- 2.6.2 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org