param: simple locking for sysfs-writable charp parameters

Since the writing to sysfs can free the old one, we need to block that
when we access the charp variables.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Reviewed-by: Takashi Iwai <tiwai@suse.de>
Tested-by: Phil Carmody <ext-phil.2.carmody@nokia.com>
Cc: Jeff Dike <jdike@addtoit.com>
Cc: Dan Williams <dcbw@redhat.com>
Cc: John W. Linville <linville@tuxdriver.com>
Cc: Jing Huang <huangj@brocade.com>
Cc: James E.J. Bottomley <James.Bottomley@suse.de>
Cc: Greg Kroah-Hartman <gregkh@suse.de>
Cc: Johannes Berg <johannes@sipsolutions.net>
Cc: David S. Miller <davem@davemloft.net>
Cc: user-mode-linux-devel@lists.sourceforge.net
Cc: libertas-dev@lists.infradead.org
Cc: linux-wireless@vger.kernel.org
Cc: netdev@vger.kernel.org
Cc: linux-scsi@vger.kernel.org
Cc: linux-usb@vger.kernel.org

1 files changed, 2 insertions, 0 deletions

diff --git a/drivers/scsi/bfa/bfad.c b/drivers/scsi/bfa/bfad.c
index 915a29d6c7a..ca04cc9d332 100644
--- a/drivers/scsi/bfa/bfad.c
+++ b/drivers/scsi/bfa/bfad.c
@@ -788,6 +788,7 @@ bfad_drv_init(struct bfad_s *bfad)
         memset(&driver_info, 0, sizeof(driver_info));
         strncpy(driver_info.version, BFAD_DRIVER_VERSION,
                 sizeof(driver_info.version) - 1);
+        __kernel_param_lock();
         if (host_name)
                 strncpy(driver_info.host_machine_name, host_name,
                         sizeof(driver_info.host_machine_name) - 1);
@@ -797,6 +798,7 @@ bfad_drv_init(struct bfad_s *bfad)
         if (os_patch)
                 strncpy(driver_info.host_os_patch, os_patch,
                         sizeof(driver_info.host_os_patch) - 1);
+        __kernel_param_unlock();
 
         strncpy(driver_info.os_device_name, bfad->pci_name,
                 sizeof(driver_info.os_device_name - 1));