mirror of
https://github.com/torvalds/linux.git
synced 2024-12-28 05:41:55 +00:00
fd537c041b
The inline documentation of _gadget_stop_activity() states that the function should be called holding the udc->lock. This however will result in a deadlock, because _gadget_stop_activity() takes the udc->lock. During normal operation _gadget_stop_activity() is always called unlocked, but in ci13xxx_stop() it's called locked, this results in the following deadlock during rmmod of a gadget driver. This patch fixes the deadlock by calling _gadget_stop_activity() always unlocked, the inline documentation is adjusted accordingly. ============================================= [ INFO: possible recursive locking detected ] 3.1.0-rc6+ #159 --------------------------------------------- rmmod/121 is trying to acquire lock: (udc_lock){-.-...}, at: [<c0229048>] _gadget_stop_activity+0x18/0x154 but task is already holding lock: (udc_lock){-.-...}, at: [<c02291e0>] ci13xxx_stop+0x5c/0x164 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(udc_lock); lock(udc_lock); *** DEADLOCK *** May be due to missing lock nesting notation 2 locks held by rmmod/121: #0: (udc_lock#2){+.+.+.}, at: [<c02286c0>] usb_gadget_unregister_driver+0x34/0x88 #1: (udc_lock){-.-...}, at: [<c02291e0>] ci13xxx_stop+0x5c/0x164 stack backtrace: [<c000d41c>] (unwind_backtrace+0x0/0xf0) from [<c0056f94>] (check_deadlock.clone.24+0x284/0x2c4) [<c0056f94>] (check_deadlock.clone.24+0x284/0x2c4) from [<c00589ac>] (validate_chain.clone.25+0x430/0x6fc) [<c00589ac>] (validate_chain.clone.25+0x430/0x6fc) from [<c0059bac>] (__lock_acquire+0x494/0x8f0) [<c0059bac>] (__lock_acquire+0x494/0x8f0) from [<c005a698>] (lock_acquire+0x98/0x1a8) [<c005a698>] (lock_acquire+0x98/0x1a8) from [<c02f12a4>] (_raw_spin_lock_irqsave+0x64/0xa0) [<c02f12a4>] (_raw_spin_lock_irqsave+0x64/0xa0) from [<c0229048>] (_gadget_stop_activity+0x18/0x154) [<c0229048>] (_gadget_stop_activity+0x18/0x154) from [<c0229234>] (ci13xxx_stop+0xb0/0x164) [<c0229234>] (ci13xxx_stop+0xb0/0x164) from [<c022867c>] (usb_gadget_remove_driver+0x88/0x98) [<c022867c>] (usb_gadget_remove_driver+0x88/0x98) from [<c02286f4>] (usb_gadget_unregister_driver+0x68/0x88) [<c02286f4>] (usb_gadget_unregister_driver+0x68/0x88) from [<c0065f2c>] (sys_delete_module+0x1fc/0x26c) [<c0065f2c>] (sys_delete_module+0x1fc/0x26c) from [<c00092a0>] (ret_fast_syscall+0x0/0x38) BUG: spinlock lockup on CPU#0, rmmod/121, c05b1644 [<c000d41c>] (unwind_backtrace+0x0/0xf0) from [<c01da000>] (do_raw_spin_lock+0x128/0x144) [<c01da000>] (do_raw_spin_lock+0x128/0x144) from [<c02f12c8>] (_raw_spin_lock_irqsave+0x88/0xa0) [<c02f12c8>] (_raw_spin_lock_irqsave+0x88/0xa0) from [<c0229048>] (_gadget_stop_activity+0x18/0x154) [<c0229048>] (_gadget_stop_activity+0x18/0x154) from [<c0229234>] (ci13xxx_stop+0xb0/0x164) [<c0229234>] (ci13xxx_stop+0xb0/0x164) from [<c022867c>] (usb_gadget_remove_driver+0x88/0x98) [<c022867c>] (usb_gadget_remove_driver+0x88/0x98) from [<c02286f4>] (usb_gadget_unregister_driver+0x68/0x88) [<c02286f4>] (usb_gadget_unregister_driver+0x68/0x88) from [<c0065f2c>] (sys_delete_module+0x1fc/0x26c) [<c0065f2c>] (sys_delete_module+0x1fc/0x26c) from [<c00092a0>] (ret_fast_syscall+0x0/0x38) Tested-by: Pavankumar Kondeti <pkondeti@codeaurora.org> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de> Signed-off-by: Felipe Balbi <balbi@ti.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> |
||
|---|---|---|
| .. | ||
| acm_ms.c | ||
| amd5536udc.c | ||
| amd5536udc.h | ||
| at91_udc.c | ||
| at91_udc.h | ||
| atmel_usba_udc.c | ||
| atmel_usba_udc.h | ||
| audio.c | ||
| cdc2.c | ||
| ci13xxx_msm.c | ||
| ci13xxx_pci.c | ||
| ci13xxx_udc.c | ||
| ci13xxx_udc.h | ||
| composite.c | ||
| config.c | ||
| dbgp.c | ||
| dummy_hcd.c | ||
| epautoconf.c | ||
| ether.c | ||
| f_acm.c | ||
| f_audio.c | ||
| f_ecm.c | ||
| f_eem.c | ||
| f_fs.c | ||
| f_hid.c | ||
| f_loopback.c | ||
| f_mass_storage.c | ||
| f_midi.c | ||
| f_ncm.c | ||
| f_obex.c | ||
| f_phonet.c | ||
| f_rndis.c | ||
| f_serial.c | ||
| f_sourcesink.c | ||
| f_subset.c | ||
| f_uvc.c | ||
| f_uvc.h | ||
| file_storage.c | ||
| fsl_mxc_udc.c | ||
| fsl_qe_udc.c | ||
| fsl_qe_udc.h | ||
| fsl_udc_core.c | ||
| fsl_usb2_udc.h | ||
| fusb300_udc.c | ||
| fusb300_udc.h | ||
| g_ffs.c | ||
| g_zero.h | ||
| gadget_chips.h | ||
| gmidi.c | ||
| goku_udc.c | ||
| goku_udc.h | ||
| hid.c | ||
| imx_udc.c | ||
| imx_udc.h | ||
| inode.c | ||
| Kconfig | ||
| langwell_udc.c | ||
| langwell_udc.h | ||
| m66592-udc.c | ||
| m66592-udc.h | ||
| Makefile | ||
| mass_storage.c | ||
| multi.c | ||
| mv_udc_core.c | ||
| mv_udc.h | ||
| ncm.c | ||
| ndis.h | ||
| net2272.c | ||
| net2272.h | ||
| net2280.c | ||
| net2280.h | ||
| nokia.c | ||
| omap_udc.c | ||
| omap_udc.h | ||
| pch_udc.c | ||
| printer.c | ||
| pxa25x_udc.c | ||
| pxa25x_udc.h | ||
| pxa27x_udc.c | ||
| pxa27x_udc.h | ||
| r8a66597-udc.c | ||
| r8a66597-udc.h | ||
| rndis.c | ||
| rndis.h | ||
| s3c2410_udc.c | ||
| s3c2410_udc.h | ||
| s3c-hsotg.c | ||
| s3c-hsudc.c | ||
| serial.c | ||
| storage_common.c | ||
| u_audio.c | ||
| u_audio.h | ||
| u_ether.c | ||
| u_ether.h | ||
| u_phonet.h | ||
| u_serial.c | ||
| u_serial.h | ||
| udc-core.c | ||
| usbstring.c | ||
| uvc_queue.c | ||
| uvc_queue.h | ||
| uvc_v4l2.c | ||
| uvc_video.c | ||
| uvc.h | ||
| webcam.c | ||
| zero.c | ||