6pack,mkiss: fix lock inconsistency
Lockdep found a locking inconsistency in the mkiss_close function: > kernel: [ INFO: inconsistent lock state ] > kernel: 2.6.39.1 #3 > kernel: --------------------------------- > kernel: inconsistent {IN-SOFTIRQ-R} -> {SOFTIRQ-ON-W} usage. > kernel: ax25ipd/2813 [HC0[0]:SC0[0]:HE1:SE1] takes: > kernel: (disc_data_lock){+++?.-}, at: [<ffffffffa018552b>] mkiss_close+0x1b/0x90 [mkiss] > kernel: {IN-SOFTIRQ-R} state was registered at: The message hints that disc_data_lock is aquired with softirqs disabled, but does not itself disable softirqs, which can in rare circumstances lead to a deadlock. The same problem is present in the 6pack driver, this patch fixes both by using write_lock_bh instead of write_lock. Reported-by: NBernard F6BVP <f6bvp@free.fr> Tested-by: NBernard F6BVP <f6bvp@free.fr> Signed-off-by: NArnd Bergmann <arnd@arndb.de> Acked-by: Ralf Baechle<ralf@linux-mips.org> Cc: stable@kernel.org Signed-off-by: NDavid S. Miller <davem@davemloft.net>
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