From mboxrd@z Thu Jan 1 00:00:00 1970 From: Lorenzo Stoakes Subject: [PATCH 01/10] mm: remove write/force parameters from __get_user_pages_locked() Date: Thu, 13 Oct 2016 01:20:11 +0100 Message-ID: <20161013002020.3062-2-lstoakes@gmail.com> References: <20161013002020.3062-1-lstoakes@gmail.com> Return-path: In-Reply-To: <20161013002020.3062-1-lstoakes@gmail.com> Sender: owner-linux-mm@kvack.org To: linux-mm@kvack.org Cc: Linus Torvalds , Jan Kara , Hugh Dickins , Dave Hansen , Rik van Riel , Mel Gorman , Andrew Morton , adi-buildroot-devel@lists.sourceforge.net, ceph-devel@vger.kernel.org, dri-devel@lists.freedesktop.org, intel-gfx@lists.freedesktop.org, kvm@vger.kernel.org, linux-alpha@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-cris-kernel@axis.com, linux-fbdev@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-ia64@vger.kernel.org, linux-kernel@vger.kernel.org, linux-media@vger.kernel.org, linux-mips@linux-mips.org, linux-rdma@vger.kernel.org, linux-s390@vger.kernel.org, linux-samsung-soc@vger.kernel.org, linux-scsi@vger.kernel.org, linux-security-module@vger.kernel.org, linux-sh@vger.kerne List-Id: ceph-devel.vger.kernel.org This patch removes the write and force parameters from __get_user_pages_locked() to make the use of FOLL_FORCE explicit in callers as use of this flag can result in surprising behaviour (and hence bugs) within the mm subsystem. Signed-off-by: Lorenzo Stoakes --- mm/gup.c | 47 +++++++++++++++++++++++++++++++++-------------- 1 file changed, 33 insertions(+), 14 deletions(-) diff --git a/mm/gup.c b/mm/gup.c index 96b2b2f..ba83942 100644 --- a/mm/gup.c +++ b/mm/gup.c @@ -729,7 +729,6 @@ static __always_inline long __get_user_pages_locked(struct task_struct *tsk, struct mm_struct *mm, unsigned long start, unsigned long nr_pages, - int write, int force, struct page **pages, struct vm_area_struct **vmas, int *locked, bool notify_drop, @@ -747,10 +746,6 @@ static __always_inline long __get_user_pages_locked(struct task_struct *tsk, if (pages) flags |= FOLL_GET; - if (write) - flags |= FOLL_WRITE; - if (force) - flags |= FOLL_FORCE; pages_done = 0; lock_dropped = false; @@ -846,9 +841,15 @@ long get_user_pages_locked(unsigned long start, unsigned long nr_pages, int write, int force, struct page **pages, int *locked) { + unsigned int flags = FOLL_TOUCH; + + if (write) + flags |= FOLL_WRITE; + if (force) + flags |= FOLL_FORCE; + return __get_user_pages_locked(current, current->mm, start, nr_pages, - write, force, pages, NULL, locked, true, - FOLL_TOUCH); + pages, NULL, locked, true, flags); } EXPORT_SYMBOL(get_user_pages_locked); @@ -869,9 +870,15 @@ __always_inline long __get_user_pages_unlocked(struct task_struct *tsk, struct m { long ret; int locked = 1; + + if (write) + gup_flags |= FOLL_WRITE; + if (force) + gup_flags |= FOLL_FORCE; + down_read(&mm->mmap_sem); - ret = __get_user_pages_locked(tsk, mm, start, nr_pages, write, force, - pages, NULL, &locked, false, gup_flags); + ret = __get_user_pages_locked(tsk, mm, start, nr_pages, pages, NULL, + &locked, false, gup_flags); if (locked) up_read(&mm->mmap_sem); return ret; @@ -963,9 +970,15 @@ long get_user_pages_remote(struct task_struct *tsk, struct mm_struct *mm, int write, int force, struct page **pages, struct vm_area_struct **vmas) { - return __get_user_pages_locked(tsk, mm, start, nr_pages, write, force, - pages, vmas, NULL, false, - FOLL_TOUCH | FOLL_REMOTE); + unsigned int flags = FOLL_TOUCH | FOLL_REMOTE; + + if (write) + flags |= FOLL_WRITE; + if (force) + flags |= FOLL_FORCE; + + return __get_user_pages_locked(tsk, mm, start, nr_pages, pages, vmas, + NULL, false, flags); } EXPORT_SYMBOL(get_user_pages_remote); @@ -979,9 +992,15 @@ long get_user_pages(unsigned long start, unsigned long nr_pages, int write, int force, struct page **pages, struct vm_area_struct **vmas) { + unsigned int flags = FOLL_TOUCH; + + if (write) + flags |= FOLL_WRITE; + if (force) + flags |= FOLL_FORCE; + return __get_user_pages_locked(current, current->mm, start, nr_pages, - write, force, pages, vmas, NULL, false, - FOLL_TOUCH); + pages, vmas, NULL, false, flags); } EXPORT_SYMBOL(get_user_pages); -- 2.10.0 -- 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 From mboxrd@z Thu Jan 1 00:00:00 1970 From: Lorenzo Stoakes Date: Thu, 13 Oct 2016 00:20:11 +0000 Subject: [PATCH 01/10] mm: remove write/force parameters from __get_user_pages_locked() Message-Id: <20161013002020.3062-2-lstoakes@gmail.com> List-Id: References: <20161013002020.3062-1-lstoakes@gmail.com> In-Reply-To: <20161013002020.3062-1-lstoakes@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: linux-mm@kvack.org Cc: Linus Torvalds , Jan Kara , Hugh Dickins , Dave Hansen , Rik van Riel , Mel Gorman , Andrew Morton , adi-buildroot-devel@lists.sourceforge.net, ceph-devel@vger.kernel.org, dri-devel@lists.freedesktop.org, intel-gfx@lists.freedesktop.org, kvm@vger.kernel.org, linux-alpha@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-cris-kernel@axis.com, linux-fbdev@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-ia64@vger.kernel.org, linux-kernel@vger.kernel.org, linux-media@vger.kernel.org, linux-mips@linux-mips.org, linux-rdma@vger.kernel.org, linux-s390@vger.kernel.org, linux-samsung-soc@vger.kernel.org, linux-scsi@vger.kernel.org, linux-security-module@vger.kernel.org, linux-sh@vger.kerne This patch removes the write and force parameters from __get_user_pages_locked() to make the use of FOLL_FORCE explicit in callers as use of this flag can result in surprising behaviour (and hence bugs) within the mm subsystem. Signed-off-by: Lorenzo Stoakes --- mm/gup.c | 47 +++++++++++++++++++++++++++++++++-------------- 1 file changed, 33 insertions(+), 14 deletions(-) diff --git a/mm/gup.c b/mm/gup.c index 96b2b2f..ba83942 100644 --- a/mm/gup.c +++ b/mm/gup.c @@ -729,7 +729,6 @@ static __always_inline long __get_user_pages_locked(struct task_struct *tsk, struct mm_struct *mm, unsigned long start, unsigned long nr_pages, - int write, int force, struct page **pages, struct vm_area_struct **vmas, int *locked, bool notify_drop, @@ -747,10 +746,6 @@ static __always_inline long __get_user_pages_locked(struct task_struct *tsk, if (pages) flags |= FOLL_GET; - if (write) - flags |= FOLL_WRITE; - if (force) - flags |= FOLL_FORCE; pages_done = 0; lock_dropped = false; @@ -846,9 +841,15 @@ long get_user_pages_locked(unsigned long start, unsigned long nr_pages, int write, int force, struct page **pages, int *locked) { + unsigned int flags = FOLL_TOUCH; + + if (write) + flags |= FOLL_WRITE; + if (force) + flags |= FOLL_FORCE; + return __get_user_pages_locked(current, current->mm, start, nr_pages, - write, force, pages, NULL, locked, true, - FOLL_TOUCH); + pages, NULL, locked, true, flags); } EXPORT_SYMBOL(get_user_pages_locked); @@ -869,9 +870,15 @@ __always_inline long __get_user_pages_unlocked(struct task_struct *tsk, struct m { long ret; int locked = 1; + + if (write) + gup_flags |= FOLL_WRITE; + if (force) + gup_flags |= FOLL_FORCE; + down_read(&mm->mmap_sem); - ret = __get_user_pages_locked(tsk, mm, start, nr_pages, write, force, - pages, NULL, &locked, false, gup_flags); + ret = __get_user_pages_locked(tsk, mm, start, nr_pages, pages, NULL, + &locked, false, gup_flags); if (locked) up_read(&mm->mmap_sem); return ret; @@ -963,9 +970,15 @@ long get_user_pages_remote(struct task_struct *tsk, struct mm_struct *mm, int write, int force, struct page **pages, struct vm_area_struct **vmas) { - return __get_user_pages_locked(tsk, mm, start, nr_pages, write, force, - pages, vmas, NULL, false, - FOLL_TOUCH | FOLL_REMOTE); + unsigned int flags = FOLL_TOUCH | FOLL_REMOTE; + + if (write) + flags |= FOLL_WRITE; + if (force) + flags |= FOLL_FORCE; + + return __get_user_pages_locked(tsk, mm, start, nr_pages, pages, vmas, + NULL, false, flags); } EXPORT_SYMBOL(get_user_pages_remote); @@ -979,9 +992,15 @@ long get_user_pages(unsigned long start, unsigned long nr_pages, int write, int force, struct page **pages, struct vm_area_struct **vmas) { + unsigned int flags = FOLL_TOUCH; + + if (write) + flags |= FOLL_WRITE; + if (force) + flags |= FOLL_FORCE; + return __get_user_pages_locked(current, current->mm, start, nr_pages, - write, force, pages, vmas, NULL, false, - FOLL_TOUCH); + pages, vmas, NULL, false, flags); } EXPORT_SYMBOL(get_user_pages); -- 2.10.0 From mboxrd@z Thu Jan 1 00:00:00 1970 Received: with ECARTIS (v1.0.0; list linux-mips); Thu, 13 Oct 2016 02:20:59 +0200 (CEST) Received: from mail-lf0-f66.google.com ([209.85.215.66]:36807 "EHLO mail-lf0-f66.google.com" rhost-flags-OK-OK-OK-OK) by eddie.linux-mips.org with ESMTP id S23992907AbcJMAUdHebo4 (ORCPT ); Thu, 13 Oct 2016 02:20:33 +0200 Received: by mail-lf0-f66.google.com with SMTP id b75so9576803lfg.3 for ; Wed, 12 Oct 2016 17:20:33 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=j8gEP7ZoklccM5hp1+G67ywmwdx3iOL8C/MYVHp7EmU=; b=JuT9DdHzwcRX2d57uF2Ok1/0XzI7mfCPFycwSWgLh256+HHE7svEZXWbxp4Dx344ri cPTt+igPbNrjH+BbF106P95yuUwSVX0U64iJtlY8AK71Z2AYJuoQwnx5vu3wXyW/emdk ZOvhoNRwvZZNJTTsjHBwe9pY0rqd61FyKapWpnalUl9qgWZZ1BnHxdXlMXlshZs7sL4C Z85jYGH0L+yRzDioCGc+CFh0MJsB8hGGvCZ/WM+JTRVZ6/I6YiHJn1Kr5v7tVlurOs8i mTBiUoggOdDLPjR1W5+lh0QXRxJPOHV0oqIZJlixH0Q0AusRDBgHFi1fCnFV9VYPDrHH Gk/A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=j8gEP7ZoklccM5hp1+G67ywmwdx3iOL8C/MYVHp7EmU=; b=KbywkthYYbKejZTxmmUe2F6xr8o0Bo4gkNzdhOGQVnvq6gq9DFtC6WFRoaqxC1olRi F3unVkADSINP4QTWE+GkXayqYjdSjFxNp3IyO/1H8t8SFrCZ0Lgqq6hIJkdgIfZ4j7jw zV1RLV3Gr9bzqRXsvvYfCnHvCJ4azO+mLDy3cgIks976+wGFnE9MOop7IACesGGoD2jL lfa2jbGA1oTOf+vdcQ/lhVhu+G2kRWifGwbvJ788ffp2nejYo4/+2cDzD1gR0hI1/mYz ykZm7ot8zIvspDV8zLBI/K5JfwPFlf17WjlK0lR2hu6xkXDqQ1XAWU6fYw+czjG1zw/Y Th8A== X-Gm-Message-State: AA6/9RmE5QrxjmhhnkAJvbabLtjOW7E01uH/HkExzQ3T7sDsfjxCphVEHwpUFufrNv/CJw== X-Received: by 10.28.54.142 with SMTP id y14mr18318wmh.11.1476318027693; Wed, 12 Oct 2016 17:20:27 -0700 (PDT) Received: from localhost (cpc94060-newt37-2-0-cust185.19-3.cable.virginm.net. [92.234.204.186]) by smtp.gmail.com with ESMTPSA id qa7sm17277959wjc.39.2016.10.12.17.20.26 (version=TLS1_2 cipher=ECDHE-RSA-CHACHA20-POLY1305 bits=256/256); Wed, 12 Oct 2016 17:20:26 -0700 (PDT) From: Lorenzo Stoakes To: linux-mm@kvack.org Cc: Linus Torvalds , Jan Kara , Hugh Dickins , Dave Hansen , Rik van Riel , Mel Gorman , Andrew Morton , adi-buildroot-devel@lists.sourceforge.net, ceph-devel@vger.kernel.org, dri-devel@lists.freedesktop.org, intel-gfx@lists.freedesktop.org, kvm@vger.kernel.org, linux-alpha@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-cris-kernel@axis.com, linux-fbdev@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-ia64@vger.kernel.org, linux-kernel@vger.kernel.org, linux-media@vger.kernel.org, linux-mips@linux-mips.org, linux-rdma@vger.kernel.org, linux-s390@vger.kernel.org, linux-samsung-soc@vger.kernel.org, linux-scsi@vger.kernel.org, linux-security-module@vger.kernel.org, linux-sh@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, netdev@vger.kernel.org, sparclinux@vger.kernel.org, x86@kernel.org, Lorenzo Stoakes Subject: [PATCH 01/10] mm: remove write/force parameters from __get_user_pages_locked() Date: Thu, 13 Oct 2016 01:20:11 +0100 Message-Id: <20161013002020.3062-2-lstoakes@gmail.com> X-Mailer: git-send-email 2.10.0 In-Reply-To: <20161013002020.3062-1-lstoakes@gmail.com> References: <20161013002020.3062-1-lstoakes@gmail.com> Return-Path: X-Envelope-To: <"|/home/ecartis/ecartis -s linux-mips"> (uid 0) X-Orcpt: rfc822;linux-mips@linux-mips.org Original-Recipient: rfc822;linux-mips@linux-mips.org X-archive-position: 55403 X-ecartis-version: Ecartis v1.0.0 Sender: linux-mips-bounce@linux-mips.org Errors-to: linux-mips-bounce@linux-mips.org X-original-sender: lstoakes@gmail.com Precedence: bulk List-help: List-unsubscribe: List-software: Ecartis version 1.0.0 List-Id: linux-mips X-List-ID: linux-mips List-subscribe: List-owner: List-post: List-archive: X-list: linux-mips This patch removes the write and force parameters from __get_user_pages_locked() to make the use of FOLL_FORCE explicit in callers as use of this flag can result in surprising behaviour (and hence bugs) within the mm subsystem. Signed-off-by: Lorenzo Stoakes --- mm/gup.c | 47 +++++++++++++++++++++++++++++++++-------------- 1 file changed, 33 insertions(+), 14 deletions(-) diff --git a/mm/gup.c b/mm/gup.c index 96b2b2f..ba83942 100644 --- a/mm/gup.c +++ b/mm/gup.c @@ -729,7 +729,6 @@ static __always_inline long __get_user_pages_locked(struct task_struct *tsk, struct mm_struct *mm, unsigned long start, unsigned long nr_pages, - int write, int force, struct page **pages, struct vm_area_struct **vmas, int *locked, bool notify_drop, @@ -747,10 +746,6 @@ static __always_inline long __get_user_pages_locked(struct task_struct *tsk, if (pages) flags |= FOLL_GET; - if (write) - flags |= FOLL_WRITE; - if (force) - flags |= FOLL_FORCE; pages_done = 0; lock_dropped = false; @@ -846,9 +841,15 @@ long get_user_pages_locked(unsigned long start, unsigned long nr_pages, int write, int force, struct page **pages, int *locked) { + unsigned int flags = FOLL_TOUCH; + + if (write) + flags |= FOLL_WRITE; + if (force) + flags |= FOLL_FORCE; + return __get_user_pages_locked(current, current->mm, start, nr_pages, - write, force, pages, NULL, locked, true, - FOLL_TOUCH); + pages, NULL, locked, true, flags); } EXPORT_SYMBOL(get_user_pages_locked); @@ -869,9 +870,15 @@ __always_inline long __get_user_pages_unlocked(struct task_struct *tsk, struct m { long ret; int locked = 1; + + if (write) + gup_flags |= FOLL_WRITE; + if (force) + gup_flags |= FOLL_FORCE; + down_read(&mm->mmap_sem); - ret = __get_user_pages_locked(tsk, mm, start, nr_pages, write, force, - pages, NULL, &locked, false, gup_flags); + ret = __get_user_pages_locked(tsk, mm, start, nr_pages, pages, NULL, + &locked, false, gup_flags); if (locked) up_read(&mm->mmap_sem); return ret; @@ -963,9 +970,15 @@ long get_user_pages_remote(struct task_struct *tsk, struct mm_struct *mm, int write, int force, struct page **pages, struct vm_area_struct **vmas) { - return __get_user_pages_locked(tsk, mm, start, nr_pages, write, force, - pages, vmas, NULL, false, - FOLL_TOUCH | FOLL_REMOTE); + unsigned int flags = FOLL_TOUCH | FOLL_REMOTE; + + if (write) + flags |= FOLL_WRITE; + if (force) + flags |= FOLL_FORCE; + + return __get_user_pages_locked(tsk, mm, start, nr_pages, pages, vmas, + NULL, false, flags); } EXPORT_SYMBOL(get_user_pages_remote); @@ -979,9 +992,15 @@ long get_user_pages(unsigned long start, unsigned long nr_pages, int write, int force, struct page **pages, struct vm_area_struct **vmas) { + unsigned int flags = FOLL_TOUCH; + + if (write) + flags |= FOLL_WRITE; + if (force) + flags |= FOLL_FORCE; + return __get_user_pages_locked(current, current->mm, start, nr_pages, - write, force, pages, vmas, NULL, false, - FOLL_TOUCH); + pages, vmas, NULL, false, flags); } EXPORT_SYMBOL(get_user_pages); -- 2.10.0 From mboxrd@z Thu Jan 1 00:00:00 1970 From: lstoakes@gmail.com (Lorenzo Stoakes) Date: Thu, 13 Oct 2016 01:20:11 +0100 Subject: [PATCH 01/10] mm: remove write/force parameters from __get_user_pages_locked() In-Reply-To: <20161013002020.3062-1-lstoakes@gmail.com> References: <20161013002020.3062-1-lstoakes@gmail.com> Message-ID: <20161013002020.3062-2-lstoakes@gmail.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org This patch removes the write and force parameters from __get_user_pages_locked() to make the use of FOLL_FORCE explicit in callers as use of this flag can result in surprising behaviour (and hence bugs) within the mm subsystem. Signed-off-by: Lorenzo Stoakes --- mm/gup.c | 47 +++++++++++++++++++++++++++++++++-------------- 1 file changed, 33 insertions(+), 14 deletions(-) diff --git a/mm/gup.c b/mm/gup.c index 96b2b2f..ba83942 100644 --- a/mm/gup.c +++ b/mm/gup.c @@ -729,7 +729,6 @@ static __always_inline long __get_user_pages_locked(struct task_struct *tsk, struct mm_struct *mm, unsigned long start, unsigned long nr_pages, - int write, int force, struct page **pages, struct vm_area_struct **vmas, int *locked, bool notify_drop, @@ -747,10 +746,6 @@ static __always_inline long __get_user_pages_locked(struct task_struct *tsk, if (pages) flags |= FOLL_GET; - if (write) - flags |= FOLL_WRITE; - if (force) - flags |= FOLL_FORCE; pages_done = 0; lock_dropped = false; @@ -846,9 +841,15 @@ long get_user_pages_locked(unsigned long start, unsigned long nr_pages, int write, int force, struct page **pages, int *locked) { + unsigned int flags = FOLL_TOUCH; + + if (write) + flags |= FOLL_WRITE; + if (force) + flags |= FOLL_FORCE; + return __get_user_pages_locked(current, current->mm, start, nr_pages, - write, force, pages, NULL, locked, true, - FOLL_TOUCH); + pages, NULL, locked, true, flags); } EXPORT_SYMBOL(get_user_pages_locked); @@ -869,9 +870,15 @@ __always_inline long __get_user_pages_unlocked(struct task_struct *tsk, struct m { long ret; int locked = 1; + + if (write) + gup_flags |= FOLL_WRITE; + if (force) + gup_flags |= FOLL_FORCE; + down_read(&mm->mmap_sem); - ret = __get_user_pages_locked(tsk, mm, start, nr_pages, write, force, - pages, NULL, &locked, false, gup_flags); + ret = __get_user_pages_locked(tsk, mm, start, nr_pages, pages, NULL, + &locked, false, gup_flags); if (locked) up_read(&mm->mmap_sem); return ret; @@ -963,9 +970,15 @@ long get_user_pages_remote(struct task_struct *tsk, struct mm_struct *mm, int write, int force, struct page **pages, struct vm_area_struct **vmas) { - return __get_user_pages_locked(tsk, mm, start, nr_pages, write, force, - pages, vmas, NULL, false, - FOLL_TOUCH | FOLL_REMOTE); + unsigned int flags = FOLL_TOUCH | FOLL_REMOTE; + + if (write) + flags |= FOLL_WRITE; + if (force) + flags |= FOLL_FORCE; + + return __get_user_pages_locked(tsk, mm, start, nr_pages, pages, vmas, + NULL, false, flags); } EXPORT_SYMBOL(get_user_pages_remote); @@ -979,9 +992,15 @@ long get_user_pages(unsigned long start, unsigned long nr_pages, int write, int force, struct page **pages, struct vm_area_struct **vmas) { + unsigned int flags = FOLL_TOUCH; + + if (write) + flags |= FOLL_WRITE; + if (force) + flags |= FOLL_FORCE; + return __get_user_pages_locked(current, current->mm, start, nr_pages, - write, force, pages, vmas, NULL, false, - FOLL_TOUCH); + pages, vmas, NULL, false, flags); } EXPORT_SYMBOL(get_user_pages); -- 2.10.0 From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Lorenzo Stoakes To: linux-mm@kvack.org Cc: Linus Torvalds , Jan Kara , Hugh Dickins , Dave Hansen , Rik van Riel , Mel Gorman , Andrew Morton , adi-buildroot-devel@lists.sourceforge.net, ceph-devel@vger.kernel.org, dri-devel@lists.freedesktop.org, intel-gfx@lists.freedesktop.org, kvm@vger.kernel.org, linux-alpha@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-cris-kernel@axis.com, linux-fbdev@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-ia64@vger.kernel.org, linux-kernel@vger.kernel.org, linux-media@vger.kernel.org, linux-mips@linux-mips.org, linux-rdma@vger.kernel.org, linux-s390@vger.kernel.org, linux-samsung-soc@vger.kernel.org, linux-scsi@vger.kernel.org, linux-security-module@vger.kernel.org, linux-sh@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, netdev@vger.kernel.org, sparclinux@vger.kernel.org, x86@kernel.org, Lorenzo Stoakes Subject: [PATCH 01/10] mm: remove write/force parameters from __get_user_pages_locked() Date: Thu, 13 Oct 2016 01:20:11 +0100 Message-Id: <20161013002020.3062-2-lstoakes@gmail.com> In-Reply-To: <20161013002020.3062-1-lstoakes@gmail.com> References: <20161013002020.3062-1-lstoakes@gmail.com> Sender: owner-linux-mm@kvack.org List-ID: This patch removes the write and force parameters from __get_user_pages_locked() to make the use of FOLL_FORCE explicit in callers as use of this flag can result in surprising behaviour (and hence bugs) within the mm subsystem. Signed-off-by: Lorenzo Stoakes --- mm/gup.c | 47 +++++++++++++++++++++++++++++++++-------------- 1 file changed, 33 insertions(+), 14 deletions(-) diff --git a/mm/gup.c b/mm/gup.c index 96b2b2f..ba83942 100644 --- a/mm/gup.c +++ b/mm/gup.c @@ -729,7 +729,6 @@ static __always_inline long __get_user_pages_locked(struct task_struct *tsk, struct mm_struct *mm, unsigned long start, unsigned long nr_pages, - int write, int force, struct page **pages, struct vm_area_struct **vmas, int *locked, bool notify_drop, @@ -747,10 +746,6 @@ static __always_inline long __get_user_pages_locked(struct task_struct *tsk, if (pages) flags |= FOLL_GET; - if (write) - flags |= FOLL_WRITE; - if (force) - flags |= FOLL_FORCE; pages_done = 0; lock_dropped = false; @@ -846,9 +841,15 @@ long get_user_pages_locked(unsigned long start, unsigned long nr_pages, int write, int force, struct page **pages, int *locked) { + unsigned int flags = FOLL_TOUCH; + + if (write) + flags |= FOLL_WRITE; + if (force) + flags |= FOLL_FORCE; + return __get_user_pages_locked(current, current->mm, start, nr_pages, - write, force, pages, NULL, locked, true, - FOLL_TOUCH); + pages, NULL, locked, true, flags); } EXPORT_SYMBOL(get_user_pages_locked); @@ -869,9 +870,15 @@ __always_inline long __get_user_pages_unlocked(struct task_struct *tsk, struct m { long ret; int locked = 1; + + if (write) + gup_flags |= FOLL_WRITE; + if (force) + gup_flags |= FOLL_FORCE; + down_read(&mm->mmap_sem); - ret = __get_user_pages_locked(tsk, mm, start, nr_pages, write, force, - pages, NULL, &locked, false, gup_flags); + ret = __get_user_pages_locked(tsk, mm, start, nr_pages, pages, NULL, + &locked, false, gup_flags); if (locked) up_read(&mm->mmap_sem); return ret; @@ -963,9 +970,15 @@ long get_user_pages_remote(struct task_struct *tsk, struct mm_struct *mm, int write, int force, struct page **pages, struct vm_area_struct **vmas) { - return __get_user_pages_locked(tsk, mm, start, nr_pages, write, force, - pages, vmas, NULL, false, - FOLL_TOUCH | FOLL_REMOTE); + unsigned int flags = FOLL_TOUCH | FOLL_REMOTE; + + if (write) + flags |= FOLL_WRITE; + if (force) + flags |= FOLL_FORCE; + + return __get_user_pages_locked(tsk, mm, start, nr_pages, pages, vmas, + NULL, false, flags); } EXPORT_SYMBOL(get_user_pages_remote); @@ -979,9 +992,15 @@ long get_user_pages(unsigned long start, unsigned long nr_pages, int write, int force, struct page **pages, struct vm_area_struct **vmas) { + unsigned int flags = FOLL_TOUCH; + + if (write) + flags |= FOLL_WRITE; + if (force) + flags |= FOLL_FORCE; + return __get_user_pages_locked(current, current->mm, start, nr_pages, - write, force, pages, vmas, NULL, false, - FOLL_TOUCH); + pages, vmas, NULL, false, flags); } EXPORT_SYMBOL(get_user_pages); -- 2.10.0 -- 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