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authorJens Freimann <jfrei@linux.vnet.ibm.com>2012-06-26 00:59:58 +0000
committerDavid S. Miller <davem@davemloft.net>2012-06-26 21:10:56 -0700
commitd7ffde35e31a81100d2d0d2c4013cbf527bb32ea (patch)
tree0939e0cabb626b4258e53a08f7a7713d534dfab5 /drivers/vhost/vhost.c
parent57efd44c8cad440fb00ef8078cb018ab2f221373 (diff)
downloadop-kernel-dev-d7ffde35e31a81100d2d0d2c4013cbf527bb32ea.zip
op-kernel-dev-d7ffde35e31a81100d2d0d2c4013cbf527bb32ea.tar.gz
vhost: use USER_DS in vhost_worker thread
On some architectures address spaces are set up in a way that this is not necessary to work properly but on some others (like s390) it is. Make sure we operate on the user address space to allow copy_xxx_user() from the vhost_worker() thread by setting it explicitly before calling use_mm() and revert it after unuse_mm(). Signed-off-by: Jens Freimann <jfrei@linux.vnet.ibm.com> Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/vhost/vhost.c')
-rw-r--r--drivers/vhost/vhost.c3
1 files changed, 3 insertions, 0 deletions
diff --git a/drivers/vhost/vhost.c b/drivers/vhost/vhost.c
index 94dbd25..112156f 100644
--- a/drivers/vhost/vhost.c
+++ b/drivers/vhost/vhost.c
@@ -191,7 +191,9 @@ static int vhost_worker(void *data)
struct vhost_dev *dev = data;
struct vhost_work *work = NULL;
unsigned uninitialized_var(seq);
+ mm_segment_t oldfs = get_fs();
+ set_fs(USER_DS);
use_mm(dev->mm);
for (;;) {
@@ -229,6 +231,7 @@ static int vhost_worker(void *data)
}
unuse_mm(dev->mm);
+ set_fs(oldfs);
return 0;
}
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