[PATCH 0/7] get_user_pages() cleanup

[PATCH 0/7] get_user_pages() cleanup

[Jan Kara]

From: Jan Kara <jack@suse.cz>

  Hello,

Now when the usage of get_user_pages() in media drivers got cleaned up, here
comes a series which removes knowledge about mmap_sem from a couple of other
drivers. Patches are trivial and standalone but please check, they are only
compile tested. If you are OK with them, either take them through your
respective trees or ack them and I can take care of pushing them to Linus
(probably through mm tree). Thanks.

After these patches there are some 12 call sites of get_user_pages() outside of
core code (mostly infiniband and RDMA). So we are slowly getting to the goal of
removing knowledge about page fault locking from drivers which will
consequently allow us to change the locking rules with reasonable effort.

								Honza

CC: Jesper Nilsson <jesper.nilsson@axis.com>
CC: linux-cris-kernel@axis.com
CC: Mikael Starvik <starvik@axis.com>
CC: linux-ia64@vger.kernel.org
CC: Tony Luck <tony.luck@intel.com>
CC: David Airlie <airlied@linux.ie>
CC: dri-devel@lists.freedesktop.org
CC: Timur Tabi <timur@freescale.com>
CC: linux-rdma@vger.kernel.org
CC: Roland Dreier <roland@kernel.org>
CC: Daniel Vetter <daniel.vetter@intel.com>
CC: David Airlie <airlied@linux.ie>
CC: dri-devel@lists.freedesktop.org
CC: Andy Walls <awalls@md.metrocast.net>
CC: linux-media@vger.kernel.org
CC: Mauro Carvalho Chehab <mchehab@osg.samsung.com>

[PATCH 2/7] ia64: Use get_user_pages_fast() in err_inject.c

[Jan Kara]

From: Jan Kara <jack@suse.cz>

Convert get_user_pages() call to get_user_pages_fast(). This actually
fixes an apparent bug where get_user_pages() has been called without
mmap_sem for an arbitrary user-provided address.

CC: Tony Luck <tony.luck@intel.com>
CC: linux-ia64@vger.kernel.org
Signed-off-by: Jan Kara <jack@suse.cz>
---
 arch/ia64/kernel/err_inject.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/arch/ia64/kernel/err_inject.c b/arch/ia64/kernel/err_inject.c
index 0c161ed6d18e..1fc8995bd8b8 100644
--- a/arch/ia64/kernel/err_inject.c
+++ b/arch/ia64/kernel/err_inject.c
@@ -142,8 +142,7 @@ store_virtual_to_phys(struct device *dev, struct device_attribute *attr,
 	u64 virt_addr=simple_strtoull(buf, NULL, 16);
 	int ret;
 
-        ret = get_user_pages(current, current->mm, virt_addr,
-                        1, VM_READ, 0, NULL, NULL);
+	ret = get_user_pages_fast(virt_addr, 1, VM_READ, NULL);
 	if (ret<=0) {
 #ifdef ERR_INJ_DEBUG
 		printk("Virtual address %lx is not existing.\n",virt_addr);
-- 
2.1.4