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-rw-r--r--drivers/infiniband/core/user_mad.c20
1 files changed, 14 insertions, 6 deletions
diff --git a/drivers/infiniband/core/user_mad.c b/drivers/infiniband/core/user_mad.c
index 1fc17940a765..ef6dd825fee9 100644
--- a/drivers/infiniband/core/user_mad.c
+++ b/drivers/infiniband/core/user_mad.c
@@ -47,7 +47,6 @@
47#include <linux/kref.h> 47#include <linux/kref.h>
48#include <linux/compat.h> 48#include <linux/compat.h>
49#include <linux/semaphore.h> 49#include <linux/semaphore.h>
50#include <linux/smp_lock.h>
51 50
52#include <asm/uaccess.h> 51#include <asm/uaccess.h>
53 52
@@ -778,23 +777,33 @@ static long ib_umad_compat_ioctl(struct file *filp, unsigned int cmd,
778} 777}
779#endif 778#endif
780 779
780/*
781 * ib_umad_open() does not need the BKL:
782 *
783 * - umad_port[] accesses are protected by port_lock, the
784 * ib_umad_port structures are properly reference counted, and
785 * everything else is purely local to the file being created, so
786 * races against other open calls are not a problem;
787 * - the ioctl method does not affect any global state outside of the
788 * file structure being operated on;
789 * - the port is added to umad_port[] as the last part of module
790 * initialization so the open method will either immediately run
791 * -ENXIO, or all required initialization will be done.
792 */
781static int ib_umad_open(struct inode *inode, struct file *filp) 793static int ib_umad_open(struct inode *inode, struct file *filp)
782{ 794{
783 struct ib_umad_port *port; 795 struct ib_umad_port *port;
784 struct ib_umad_file *file; 796 struct ib_umad_file *file;
785 int ret = 0; 797 int ret = 0;
786 798
787 lock_kernel();
788 spin_lock(&port_lock); 799 spin_lock(&port_lock);
789 port = umad_port[iminor(inode) - IB_UMAD_MINOR_BASE]; 800 port = umad_port[iminor(inode) - IB_UMAD_MINOR_BASE];
790 if (port) 801 if (port)
791 kref_get(&port->umad_dev->ref); 802 kref_get(&port->umad_dev->ref);
792 spin_unlock(&port_lock); 803 spin_unlock(&port_lock);
793 804
794 if (!port) { 805 if (!port)
795 unlock_kernel();
796 return -ENXIO; 806 return -ENXIO;
797 }
798 807
799 mutex_lock(&port->file_mutex); 808 mutex_lock(&port->file_mutex);
800 809
@@ -823,7 +832,6 @@ static int ib_umad_open(struct inode *inode, struct file *filp)
823 832
824out: 833out:
825 mutex_unlock(&port->file_mutex); 834 mutex_unlock(&port->file_mutex);
826 unlock_kernel();
827 return ret; 835 return ret;
828} 836}
829 837