Bjørn Mork b086b6b10d USB: cdc-wdm: fix lockup on error in wdm_read ... Clear the WDM_READ flag on empty reads to avoid running forever in an infinite tight loop, causing lockups: Jul 1 21:58:11 nemi kernel: [ 3658.898647] qmi_wwan 2-1:1.2: Unexpected error -71 Jul 1 21:58:36 nemi kernel: [ 3684.072021] BUG: soft lockup - CPU#0 stuck for 23s! [qmi.pl:12235] Jul 1 21:58:36 nemi kernel: [ 3684.072212] CPU 0 Jul 1 21:58:36 nemi kernel: [ 3684.072355] Jul 1 21:58:36 nemi kernel: [ 3684.072367] Pid: 12235, comm: qmi.pl Tainted: P O 3.5.0-rc2+ #13 LENOVO 2776LEG/2776LEG Jul 1 21:58:36 nemi kernel: [ 3684.072383] RIP: 0010:[<ffffffffa0635008>] [<ffffffffa0635008>] spin_unlock_irq+0x8/0xc [cdc_wdm] Jul 1 21:58:36 nemi kernel: [ 3684.072388] RSP: 0018:ffff88022dca1e70 EFLAGS: 00000282 Jul 1 21:58:36 nemi kernel: [ 3684.072393] RAX: ffff88022fc3f650 RBX: ffffffff811c56f7 RCX: 00000001000ce8c1 Jul 1 21:58:36 nemi kernel: [ 3684.072398] RDX: 0000000000000010 RSI: 000000000267d810 RDI: ffff88022fc3f650 Jul 1 21:58:36 nemi kernel: [ 3684.072403] RBP: ffff88022dca1eb0 R08: ffffffffa063578e R09: 0000000000000000 Jul 1 21:58:36 nemi kernel: [ 3684.072407] R10: 0000000000000008 R11: 0000000000000246 R12: 0000000000000002 Jul 1 21:58:36 nemi kernel: [ 3684.072412] R13: 0000000000000246 R14: ffffffff00000002 R15: ffff8802281d8c88 Jul 1 21:58:36 nemi kernel: [ 3684.072418] FS: 00007f666a260700(0000) GS:ffff88023bc00000(0000) knlGS:0000000000000000 Jul 1 21:58:36 nemi kernel: [ 3684.072423] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 Jul 1 21:58:36 nemi kernel: [ 3684.072428] CR2: 000000000270d9d8 CR3: 000000022e865000 CR4: 00000000000007f0 Jul 1 21:58:36 nemi kernel: [ 3684.072433] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 Jul 1 21:58:36 nemi kernel: [ 3684.072438] DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Jul 1 21:58:36 nemi kernel: [ 3684.072444] Process qmi.pl (pid: 12235, threadinfo ffff88022dca0000, task ffff88022ff76380) Jul 1 21:58:36 nemi kernel: [ 3684.072448] Stack: Jul 1 21:58:36 nemi kernel: [ 3684.072458] ffffffffa063592e 0000000100020000 ffff88022fc3f650 ffff88022fc3f6a8 Jul 1 21:58:36 nemi kernel: [ 3684.072466] 0000000000000200 0000000100000000 000000000267d810 0000000000000000 Jul 1 21:58:36 nemi kernel: [ 3684.072475] 0000000000000000 ffff880212cfb6d0 0000000000000200 ffff880212cfb6c0 Jul 1 21:58:36 nemi kernel: [ 3684.072479] Call Trace: Jul 1 21:58:36 nemi kernel: [ 3684.072489] [<ffffffffa063592e>] ? wdm_read+0x1a0/0x263 [cdc_wdm] Jul 1 21:58:36 nemi kernel: [ 3684.072500] [<ffffffff8110adb7>] ? vfs_read+0xa1/0xfb Jul 1 21:58:36 nemi kernel: [ 3684.072509] [<ffffffff81040589>] ? alarm_setitimer+0x35/0x64 Jul 1 21:58:36 nemi kernel: [ 3684.072517] [<ffffffff8110aec7>] ? sys_read+0x45/0x6e Jul 1 21:58:36 nemi kernel: [ 3684.072525] [<ffffffff813725f9>] ? system_call_fastpath+0x16/0x1b Jul 1 21:58:36 nemi kernel: [ 3684.072557] Code: <66> 66 90 c3 83 ff ed 89 f8 74 16 7f 06 83 ff a1 75 0a c3 83 ff f4 The WDM_READ flag is normally cleared by wdm_int_callback before resubmitting the read urb, and set by wdm_in_callback when this urb returns with data or an error. But a crashing device may cause both a read error and cancelling all urbs. Make sure that the flag is cleared by wdm_read if the buffer is empty. We don't clear the flag on errors, as there may be pending data in the buffer which should be processed. The flag will instead be cleared on the next wdm_read call. Cc: stable <stable@vger.kernel.org> Signed-off-by: Bjørn Mork <bjorn@mork.no> Acked-by: Oliver Neukum <oneukum@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>		2012-07-05 16:04:58 -07:00
..
cdc-acm.c
cdc-acm.h
cdc-wdm.c
Kconfig
Makefile
usblp.c
usbtmc.c