diff options
| author | Baolin Wang <baolin.wang@linaro.org> | 2016-12-08 19:55:22 +0800 |
|---|---|---|
| committer | Michael Bestas <mkbestas@lineageos.org> | 2019-12-23 23:43:36 +0200 |
| commit | 96d762ec65e7339b71e0838b3e484dc6d311ca78 (patch) | |
| tree | 91f85de9b0f0068b84182d1216e21a3e9065776d /scripts | |
| parent | 3c81240cc10fdd00f3abcf7d70c9cdc74b86ca15 (diff) | |
usb: gadget: f_fs: Fix possibe deadlock
commit b3ce3ce02d146841af012d08506b4071db8ffde3 upstream.
When system try to close /dev/usb-ffs/adb/ep0 on one core, at the same
time another core try to attach new UDC, which will cause deadlock as
below scenario. Thus we should release ffs lock before issuing
unregister_gadget_item().
[ 52.642225] c1 ======================================================
[ 52.642228] c1 [ INFO: possible circular locking dependency detected ]
[ 52.642236] c1 4.4.6+ #1 Tainted: G W O
[ 52.642241] c1 -------------------------------------------------------
[ 52.642245] c1 usb ffs open/2808 is trying to acquire lock:
[ 52.642270] c0 (udc_lock){+.+.+.}, at: [<ffffffc00065aeec>]
usb_gadget_unregister_driver+0x3c/0xc8
[ 52.642272] c1 but task is already holding lock:
[ 52.642283] c0 (ffs_lock){+.+.+.}, at: [<ffffffc00066b244>]
ffs_data_clear+0x30/0x140
[ 52.642285] c1 which lock already depends on the new lock.
[ 52.642287] c1
the existing dependency chain (in reverse order) is:
[ 52.642295] c0
-> #1 (ffs_lock){+.+.+.}:
[ 52.642307] c0 [<ffffffc00012340c>] __lock_acquire+0x20f0/0x2238
[ 52.642314] c0 [<ffffffc000123b54>] lock_acquire+0xe4/0x298
[ 52.642322] c0 [<ffffffc000aaf6e8>] mutex_lock_nested+0x7c/0x3cc
[ 52.642328] c0 [<ffffffc00066f7bc>] ffs_func_bind+0x504/0x6e8
[ 52.642334] c0 [<ffffffc000654004>] usb_add_function+0x84/0x184
[ 52.642340] c0 [<ffffffc000658ca4>] configfs_composite_bind+0x264/0x39c
[ 52.642346] c0 [<ffffffc00065b348>] udc_bind_to_driver+0x58/0x11c
[ 52.642352] c0 [<ffffffc00065b49c>] usb_udc_attach_driver+0x90/0xc8
[ 52.642358] c0 [<ffffffc0006598e0>] gadget_dev_desc_UDC_store+0xd4/0x128
[ 52.642369] c0 [<ffffffc0002c14e8>] configfs_write_file+0xd0/0x13c
[ 52.642376] c0 [<ffffffc00023c054>] vfs_write+0xb8/0x214
[ 52.642381] c0 [<ffffffc00023cad4>] SyS_write+0x54/0xb0
[ 52.642388] c0 [<ffffffc000085ff0>] el0_svc_naked+0x24/0x28
[ 52.642395] c0
-> #0 (udc_lock){+.+.+.}:
[ 52.642401] c0 [<ffffffc00011e3d0>] print_circular_bug+0x84/0x2e4
[ 52.642407] c0 [<ffffffc000123454>] __lock_acquire+0x2138/0x2238
[ 52.642412] c0 [<ffffffc000123b54>] lock_acquire+0xe4/0x298
[ 52.642420] c0 [<ffffffc000aaf6e8>] mutex_lock_nested+0x7c/0x3cc
[ 52.642427] c0 [<ffffffc00065aeec>] usb_gadget_unregister_driver+0x3c/0xc8
[ 52.642432] c0 [<ffffffc00065995c>] unregister_gadget_item+0x28/0x44
[ 52.642439] c0 [<ffffffc00066b34c>] ffs_data_clear+0x138/0x140
[ 52.642444] c0 [<ffffffc00066b374>] ffs_data_reset+0x20/0x6c
[ 52.642450] c0 [<ffffffc00066efd0>] ffs_data_closed+0xac/0x12c
[ 52.642454] c0 [<ffffffc00066f070>] ffs_ep0_release+0x20/0x2c
[ 52.642460] c0 [<ffffffc00023dbe4>] __fput+0xb0/0x1f4
[ 52.642466] c0 [<ffffffc00023dd9c>] ____fput+0x20/0x2c
[ 52.642473] c0 [<ffffffc0000ee944>] task_work_run+0xb4/0xe8
[ 52.642482] c0 [<ffffffc0000cd45c>] do_exit+0x360/0xb9c
[ 52.642487] c0 [<ffffffc0000cf228>] do_group_exit+0x4c/0xb0
[ 52.642494] c0 [<ffffffc0000dd3c8>] get_signal+0x380/0x89c
[ 52.642501] c0 [<ffffffc00008a8f0>] do_signal+0x154/0x518
[ 52.642507] c0 [<ffffffc00008af00>] do_notify_resume+0x70/0x78
[ 52.642512] c0 [<ffffffc000085ee8>] work_pending+0x1c/0x20
[ 52.642514] c1
other info that might help us debug this:
[ 52.642517] c1 Possible unsafe locking scenario:
[ 52.642518] c1 CPU0 CPU1
[ 52.642520] c1 ---- ----
[ 52.642525] c0 lock(ffs_lock);
[ 52.642529] c0 lock(udc_lock);
[ 52.642533] c0 lock(ffs_lock);
[ 52.642537] c0 lock(udc_lock);
[ 52.642539] c1
*** DEADLOCK ***
[ 52.642543] c1 1 lock held by usb ffs open/2808:
[ 52.642555] c0 #0: (ffs_lock){+.+.+.}, at: [<ffffffc00066b244>]
ffs_data_clear+0x30/0x140
[ 52.642557] c1 stack backtrace:
[ 52.642563] c1 CPU: 1 PID: 2808 Comm: usb ffs open Tainted: G
[ 52.642565] c1 Hardware name: Spreadtrum SP9860g Board (DT)
[ 52.642568] c1 Call trace:
[ 52.642573] c1 [<ffffffc00008b430>] dump_backtrace+0x0/0x170
[ 52.642577] c1 [<ffffffc00008b5c0>] show_stack+0x20/0x28
[ 52.642583] c1 [<ffffffc000422694>] dump_stack+0xa8/0xe0
[ 52.642587] c1 [<ffffffc00011e548>] print_circular_bug+0x1fc/0x2e4
[ 52.642591] c1 [<ffffffc000123454>] __lock_acquire+0x2138/0x2238
[ 52.642595] c1 [<ffffffc000123b54>] lock_acquire+0xe4/0x298
[ 52.642599] c1 [<ffffffc000aaf6e8>] mutex_lock_nested+0x7c/0x3cc
[ 52.642604] c1 [<ffffffc00065aeec>] usb_gadget_unregister_driver+0x3c/0xc8
[ 52.642608] c1 [<ffffffc00065995c>] unregister_gadget_item+0x28/0x44
[ 52.642613] c1 [<ffffffc00066b34c>] ffs_data_clear+0x138/0x140
[ 52.642618] c1 [<ffffffc00066b374>] ffs_data_reset+0x20/0x6c
[ 52.642621] c1 [<ffffffc00066efd0>] ffs_data_closed+0xac/0x12c
[ 52.642625] c1 [<ffffffc00066f070>] ffs_ep0_release+0x20/0x2c
[ 52.642629] c1 [<ffffffc00023dbe4>] __fput+0xb0/0x1f4
[ 52.642633] c1 [<ffffffc00023dd9c>] ____fput+0x20/0x2c
[ 52.642636] c1 [<ffffffc0000ee944>] task_work_run+0xb4/0xe8
[ 52.642640] c1 [<ffffffc0000cd45c>] do_exit+0x360/0xb9c
[ 52.642644] c1 [<ffffffc0000cf228>] do_group_exit+0x4c/0xb0
[ 52.642647] c1 [<ffffffc0000dd3c8>] get_signal+0x380/0x89c
[ 52.642651] c1 [<ffffffc00008a8f0>] do_signal+0x154/0x518
[ 52.642656] c1 [<ffffffc00008af00>] do_notify_resume+0x70/0x78
[ 52.642659] c1 [<ffffffc000085ee8>] work_pending+0x1c/0x20
Change-Id: I4f084295389670cab0f7b7ee2d866e263f09f6da
Acked-by: Michal Nazarewicz <mina86@mina86.com>
Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Cc: Jerry Zhang <zhangjerry@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'scripts')
0 files changed, 0 insertions, 0 deletions