linux/drivers/hid/hid-debug.c, branch v3.12.10

HID: debug: fix RCU preemption issue

2013-05-06T11:07:33Z

Commit 2353f2bea ("HID: protect hid_debug_list") introduced mutex locking around debug_list access to prevent SMP races when debugfs nodes are being operated upon by multiple userspace processess. mutex is not a proper synchronization primitive though, as the hid-debug callbacks are being called from atomic contexts. We also have to be careful about disabling IRQs when taking the lock to prevent deadlock against IRQ handlers. Benjamin reports this has also been reported in RH bugzilla as bug #958935. =============================== [ INFO: suspicious RCU usage. ] 3.9.0+ #94 Not tainted ------------------------------- include/linux/rcupdate.h:476 Illegal context switch in RCU read-side critical section! other info that might help us debug this: rcu_scheduler_active = 1, debug_locks = 0 4 locks held by Xorg/5502: #0: (&evdev->mutex){+.+...}, at: [] evdev_write+0x6d/0x160 #1: (&(&dev->event_lock)->rlock#2){-.-...}, at: [] input_inject_event+0x5b/0x230 #2: (rcu_read_lock){.+.+..}, at: [] input_inject_event+0x42/0x230 #3: (&(&usbhid->lock)->rlock){-.....}, at: [] usb_hidinput_input_event+0x89/0x120 stack backtrace: CPU: 0 PID: 5502 Comm: Xorg Not tainted 3.9.0+ #94 Hardware name: Dell Inc. OptiPlex 390/0M5DCD, BIOS A09 07/24/2012 0000000000000001 ffff8800689c7c38 ffffffff816f249f ffff8800689c7c68 ffffffff810acb1d 0000000000000000 ffffffff81a03ac7 000000000000019d 0000000000000000 ffff8800689c7c90 ffffffff8107cda7 0000000000000000 Call Trace: [] dump_stack+0x19/0x1b [] lockdep_rcu_suspicious+0xfd/0x130 [] __might_sleep+0xc7/0x230 [] mutex_lock_nested+0x40/0x3a0 [] ? vsnprintf+0x354/0x640 [] hid_debug_event+0x34/0x100 [] hid_dump_input+0x67/0xa0 [] hid_set_field+0x50/0x120 [] usb_hidinput_input_event+0x9a/0x120 [] input_handle_event+0x8e/0x530 [] input_inject_event+0x1d0/0x230 [] ? input_inject_event+0x42/0x230 [] evdev_write+0xde/0x160 [] vfs_write+0xc8/0x1f0 [] SyS_write+0x55/0xa0 [] system_call_fastpath+0x16/0x1b BUG: sleeping function called from invalid context at kernel/mutex.c:413 in_atomic(): 1, irqs_disabled(): 1, pid: 5502, name: Xorg INFO: lockdep is turned off. irq event stamp: 1098574 hardirqs last enabled at (1098573): [] _raw_spin_unlock_irqrestore+0x3f/0x70 hardirqs last disabled at (1098574): [] _raw_spin_lock_irqsave+0x25/0xa0 softirqs last enabled at (1098306): [] __do_softirq+0x18f/0x3c0 softirqs last disabled at (1097867): [] irq_exit+0xa5/0xb0 CPU: 0 PID: 5502 Comm: Xorg Not tainted 3.9.0+ #94 Hardware name: Dell Inc. OptiPlex 390/0M5DCD, BIOS A09 07/24/2012 ffffffff81a03ac7 ffff8800689c7c68 ffffffff816f249f ffff8800689c7c90 ffffffff8107ce60 0000000000000000 ffff8800689c7fd8 ffff88006a62c800 ffff8800689c7d10 ffffffff816f7770 ffff8800689c7d00 ffffffff81312ac4 Call Trace: [] dump_stack+0x19/0x1b [] __might_sleep+0x180/0x230 [] mutex_lock_nested+0x40/0x3a0 [] ? vsnprintf+0x354/0x640 [] hid_debug_event+0x34/0x100 [] hid_dump_input+0x67/0xa0 [] hid_set_field+0x50/0x120 [] usb_hidinput_input_event+0x9a/0x120 [] input_handle_event+0x8e/0x530 [] input_inject_event+0x1d0/0x230 [] ? input_inject_event+0x42/0x230 [] evdev_write+0xde/0x160 [] vfs_write+0xc8/0x1f0 [] SyS_write+0x55/0xa0 [] system_call_fastpath+0x16/0x1b Reported-by: majianpeng Reported-by: Benjamin Tissoires Reviewed-by: Dmitry Torokhov Signed-off-by: Jiri Kosina

HID: protect hid_debug_list

2013-04-30T08:09:31Z

Accesses to hid_device->hid_debug_list are not serialized properly, which could result in SMP concurrency issues when HID debugfs events are accessesed by multiple userspace processess. Serialize all the list operations by a mutex. Spotted by Al Viro. Signed-off-by: Jiri Kosina

HID: debug: break out hid_dump_report() into hid-debug

2013-04-30T08:09:06Z

No semantic changes, but hid_dump_report should be in hid-debug.c, not in hid-core.c Signed-off-by: Benjamin Tissoires Signed-off-by: Jiri Kosina

HID: hid-debug: Show rdesc for unclaimed devices

2012-08-27T15:01:21Z

Since commit a7197c2e, the raw report descriptor is available also for unclaimed devices. This patchs make it show in the rdesc debugfs node. Signed-off-by: Henrik Rydberg Signed-off-by: Jiri Kosina

Merge branches 'hyperv', 'multitouch', 'roccat', 'upstream', 'upstream-fixes', 'wacom' and 'wiimote' into for-linus

2012-01-05T14:51:02Z

HID: debugfs: decode Generic Device Controls Usage Page

2011-11-19T11:19:00Z

The USB HID Usage Tables spec defines page 6 for Generic Device Controls, the most useful of which (to me) is Battery Strength. Signed-off-by: Jeremy Fitzhardinge Signed-off-by: Jiri Kosina

hid: Fix up files needing export.h for EXPORT_SYMBOL

2011-10-31T23:31:18Z

With module.h being implicitly everywhere via device.h, the absence of explicitly including something for EXPORT_SYMBOL went unnoticed. Since we are heading to fix things up and clean module.h from the device.h file, we need to explicitly include these files now. Signed-off-by: Paul Gortmaker

HID: hid-debug: Show application usage for each collection.

2011-08-16T09:37:29Z

Signed-off-by: jeffbrown@android.com Reviewed-by: Benjamin Tissoires Signed-off-by: Jiri Kosina

Fix common misspellings

2011-03-31T14:26:23Z

Fixes generated by 'codespell' and manually reviewed. Signed-off-by: Lucas De Marchi

HID: Add and use hid_: dev_ equivalents

2010-12-10T14:10:38Z

Neaten current uses of dev_ by adding and using hid specific hid_ macros. Convert existing uses of dev_ uses to hid_. Convert hid-pidff printk uses to hid_. Remove err_hid and use hid_err instead. Add missing newlines to logging messages where necessary. Coalesce format strings. Add and use pr_fmt(fmt) KBUILD_MODNAME ": " fmt Other miscellaneous changes: Add const struct hid_device * argument to hid-core functions extract() and implement() so hid_ can be used by them. Fix bad indentation in hid-core hid_input_field function that calls extract() function above. Signed-off-by: Joe Perches Signed-off-by: Jiri Kosina