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70 Commits

Author SHA1 Message Date
Thomas Gleixner 1a59d1b8e0 treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 156
Based on 1 normalized pattern(s):

  this program is free software you can redistribute it and or modify
  it under the terms of the gnu general public license as published by
  the free software foundation either version 2 of the license or at
  your option any later version this program is distributed in the
  hope that it will be useful but without any warranty without even
  the implied warranty of merchantability or fitness for a particular
  purpose see the gnu general public license for more details you
  should have received a copy of the gnu general public license along
  with this program if not write to the free software foundation inc
  59 temple place suite 330 boston ma 02111 1307 usa

extracted by the scancode license scanner the SPDX license identifier

  GPL-2.0-or-later

has been chosen to replace the boilerplate/reference in 1334 file(s).

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Richard Fontana <rfontana@redhat.com>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190527070033.113240726@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-30 11:26:35 -07:00
Breno Leitao f11274396a HID: hiddev: fix potential Spectre v1
uref->usage_index can be indirectly controlled by userspace, hence leading
to a potential exploitation of the Spectre variant 1 vulnerability.

This field is used as an array index by the hiddev_ioctl_usage() function,
when 'cmd' is either HIDIOCGCOLLECTIONINDEX, HIDIOCGUSAGES or
HIDIOCSUSAGES.

For cmd == HIDIOCGCOLLECTIONINDEX case, uref->usage_index is compared to
field->maxusage and then used as an index to dereference field->usage
array. The same thing happens to the cmd == HIDIOC{G,S}USAGES cases, where
uref->usage_index is checked against an array maximum value and then it is
used as an index in an array.

This is a summary of the HIDIOCGCOLLECTIONINDEX case, which matches the
traditional Spectre V1 first load:

	copy_from_user(uref, user_arg, sizeof(*uref))
	if (uref->usage_index >= field->maxusage)
		goto inval;
	i = field->usage[uref->usage_index].collection_index;
	return i;

This patch fixes this by sanitizing field uref->usage_index before using it
to index field->usage (HIDIOCGCOLLECTIONINDEX) or field->value in
HIDIOC{G,S}USAGES arrays, thus, avoiding speculation in the first load.

Cc: <stable@vger.kernel.org>
Signed-off-by: Breno Leitao <leitao@debian.org>
--

v2: Contemplate cmd == HIDIOC{G,S}USAGES case
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2018-10-26 17:06:24 +02:00
Gustavo A. R. Silva 4f65245f2d HID: hiddev: fix potential Spectre v1
uref->field_index, uref->usage_index, finfo.field_index and cinfo.index can be
indirectly controlled by user-space, hence leading to a potential exploitation
of the Spectre variant 1 vulnerability.

This issue was detected with the help of Smatch:

drivers/hid/usbhid/hiddev.c:473 hiddev_ioctl_usage() warn: potential spectre issue 'report->field' (local cap)
drivers/hid/usbhid/hiddev.c:477 hiddev_ioctl_usage() warn: potential spectre issue 'field->usage' (local cap)
drivers/hid/usbhid/hiddev.c:757 hiddev_ioctl() warn: potential spectre issue 'report->field' (local cap)
drivers/hid/usbhid/hiddev.c:801 hiddev_ioctl() warn: potential spectre issue 'hid->collection' (local cap)

Fix this by sanitizing such structure fields before using them to index
report->field, field->usage and hid->collection

Notice that given that speculation windows are large, the policy is
to kill the speculation on the first load and not worry if it can be
completed with a dependent load/store [1].

[1] https://marc.info/?l=linux-kernel&m=152449131114778&w=2

Cc: stable@vger.kernel.org
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2018-07-09 14:31:14 +02:00
Linus Torvalds a9a08845e9 vfs: do bulk POLL* -> EPOLL* replacement
This is the mindless scripted replacement of kernel use of POLL*
variables as described by Al, done by this script:

    for V in IN OUT PRI ERR RDNORM RDBAND WRNORM WRBAND HUP RDHUP NVAL MSG; do
        L=`git grep -l -w POLL$V | grep -v '^t' | grep -v /um/ | grep -v '^sa' | grep -v '/poll.h$'|grep -v '^D'`
        for f in $L; do sed -i "-es/^\([^\"]*\)\(\<POLL$V\>\)/\\1E\\2/" $f; done
    done

with de-mangling cleanups yet to come.

NOTE! On almost all architectures, the EPOLL* constants have the same
values as the POLL* constants do.  But they keyword here is "almost".
For various bad reasons they aren't the same, and epoll() doesn't
actually work quite correctly in some cases due to this on Sparc et al.

The next patch from Al will sort out the final differences, and we
should be all done.

Scripted-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-02-11 14:34:03 -08:00
Al Viro afc9a42b74 the rest of drivers/*: annotate ->poll() instances
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-11-28 11:06:58 -05:00
Dmitry Torokhov 9a83563fb3 HID: hiddev: use hid_hw_power instead of usbhid_get/put_power
Instead of calling into usbhid code directly, let's use the standard
accessors for the transport HID drivers, and stop clobbering their error
codes with -EIO.

This also allows us to remove usbhid_get/put_power(), leaving only
usbhid_power().

Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2017-06-08 13:56:09 +02:00
Dmitry Torokhov d36b7d4c27 HID: hiddev: use hid_hw_open/close instead of usbhid_open/close
Instead of calling into usbhid code directly, let's use the standard
accessors for the transport HID drivers, and stop clobbering their errors
with -EIO.

This also allows us make usbhid_open and close static.

Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Reviewed-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2017-06-08 13:56:08 +02:00
Jiri Kosina 4d6ca227c7 Merge branch 'for-4.12/asus' into for-linus 2017-05-02 11:02:41 +02:00
Jaejoong Kim 733aca9030 HID: hiddev: reallocate hiddev's minor number
We need to store the minor number each drivers. In case of hidraw, the
minor number is stored stores in struct hidraw. But hiddev's minor is
located in struct hid_device.

The hid-core driver announces a kernel message which driver is loaded when
HID device connected, but hiddev's minor number is always zero. To proper
display hiddev's minor number, we need to store the minor number asked from
usb core and do some refactoring work (move from hiddev.c to hiddev.h) to
access hiddev in hid-core.

[jkosina@suse.cz: rebase on top of newer codebase]
Reviewed-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Jaejoong Kim <climbbb.kim@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2017-03-21 15:24:01 +01:00
Benjamin Tissoires 9143059faf HID: remove initial reading of reports at connect
It looks like a bunch of devices do not like to be polled
for their reports at init time. When you look into the details,
it seems that for those that are requiring the quirk
HID_QUIRK_NO_INIT_REPORTS, the driver fails to retrieve part
of the features/inputs while others (more generic) work.

IMO, it should be acceptable to remove the need for the quirk
in the general case. On the small amount of cases where
we actually need to read the current values, the driver
in charge (hid-mt or wacom) already retrieves the features
manually.

There are 2 cases where we might need to retrieve the reports at
init:
1. hiddev devices with specific use-space tool
2. a device that would require the driver to fetch a specific
   feature/input at plug

For case 2, I have seen this a few time on hid-multitouch. It
is solved in hid-multitouch directly by fetching the feature.
I hope it won't be too common and this can be solved on a per-case
basis (crossing fingers).

For case 1, we moved the implementation of HID_QUIRK_NO_INIT_REPORTS
in hiddev. When somebody starts calling ioctls that needs an initial
update, the hiddev device will fetch the initial state of the reports
to mimic the current behavior. This adds a small amount of time during
the first HIDIOCGUSAGE(S), but it should be acceptable in
most cases. To keep the currently known broken devices, we have to
keep around HID_QUIRK_NO_INIT_REPORTS, but the scope will only be
for hiddev.

Note that I don't think hidraw would be affected and I checked that
the FF drivers that need to interact with the report fields are all
using output reports, which are not initialized by
usbhid_init_reports().

NO_INIT_INPUT_REPORTS is then replaced by HID_QUIRK_NO_INIT_REPORTS:
there is no point keeping it for just one device.

Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2017-03-21 14:59:56 +01:00
Ingo Molnar 174cd4b1e5 sched/headers: Prepare to move signal wakeup & sigpending methods from <linux/sched.h> into <linux/sched/signal.h>
Fix up affected files that include this signal functionality via sched.h.

Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-03-02 08:42:32 +01:00
Scott Bauer 93a2001bdf HID: hiddev: validate num_values for HIDIOCGUSAGES, HIDIOCSUSAGES commands
This patch validates the num_values parameter from userland during the
HIDIOCGUSAGES and HIDIOCSUSAGES commands. Previously, if the report id was set
to HID_REPORT_ID_UNKNOWN, we would fail to validate the num_values parameter
leading to a heap overflow.

Cc: stable@vger.kernel.org
Signed-off-by: Scott Bauer <sbauer@plzdonthack.me>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2016-06-24 10:21:39 +02:00
Benjamin Tissoires b7966a4d7b HID: use hid_hw_wait() instead of direct call to usbhid
This removes most of the dependencies between hid drivers and usbhid.

The patch was constructed by replacing all occurences of
usbhid_wait_io() by its hid_hw_wait() counterpart.
Then, drivers not requiring USB_HID anymore have their USB_HID
dependency cleaned in the Kconfig file.

As of today, few drivers are still requiring an explicit USB layer
dependency:
* ntrig (a patch is on its way)
* multitouch (one patch following and another on its way)
* lenovo tpkbd
* roccat
* sony

The last three are two deeply using direct calls to the usb subsystem
to be able to be cleaned right now.

Signed-off-by: Benjamin Tissoires <benjamin.tissoires@gmail.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2013-02-25 13:26:41 +01:00
Benjamin Tissoires d881427253 HID: use hid_hw_request() instead of direct call to usbhid
This allows the hid drivers to be independent from the transport layer.

The patch was constructed by replacing all occurences of
usbhid_submit_report() by its hid_hw_request() counterpart.
Then, drivers not requiring USB_HID anymore have their USB_HID
dependency cleaned in the Kconfig file.

Finally, few drivers still depends on USB_HID. Many of them
are requiring the io wait callback. They are found in the next patch.

Signed-off-by: Benjamin Tissoires <benjamin.tissoires@gmail.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>

For the sensor-hub part:
Tested-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2013-02-25 13:26:41 +01:00
Jiri Kosina 13f1962402 HID: hiddev: fix nonblocking read semantics wrt EIO/ERESTARTSYS
When the file has been open in non-blocking mode, EIO or ERESTARTSYS
would never be returned even if they should (for example when device
has been unplugged, you want EIO and not EAGAIN to be returned).

Move the O_NONBLOCK check after other checks have been performed.

Base on similar patch done to hidraw by
Founder Fang <founder.fang@gmail.com>

Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2012-11-28 00:10:44 +01:00
Tushar Behera d339f61d14 HID: hiddev: Remove redundant check on unsigned variable
No need to check whether unsigned variable is less than 0.

CC: Jiri Kosina <jkosina@suse.cz>
CC: linux-usb@vger.kernel.org
CC: linux-input@vger.kernel.org
Signed-off-by: Tushar Behera <tushar.behera@linaro.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2012-11-16 10:26:23 +01:00
Havard Skinnemoen d4f0e4daf0 HID: hiddev: Use vzalloc to allocate hiddev_list
Everytime a HID device is opened, a new hiddev_list is allocated with
kzalloc. This requires 64KB of physically contiguous memory, which could
easily push a heavily loaded system over the edge.

Allocating the same amount of memory with vmalloc shouldn't be nearly as
demanding, so let's do that instead. The memory isn't used for DMA and
doesn't look particularly performance sensitive, so this should be safe.

Signed-off-by: Havard Skinnemoen <hskinnemoen@google.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2012-04-27 16:03:40 +02:00
Ming Lei ba18311dff HID: usbhid: fix dead lock between open and disconect
There is no reason to hold hiddev->existancelock before
calling usb_deregister_dev, so move it out of the lock.

The patch fixes the lockdep warning below.

[ 5733.386271] ======================================================
[ 5733.386274] [ INFO: possible circular locking dependency detected ]
[ 5733.386278] 3.2.0-custom-next-20120111+ #1 Not tainted
[ 5733.386281] -------------------------------------------------------
[ 5733.386284] khubd/186 is trying to acquire lock:
[ 5733.386288]  (minor_rwsem){++++.+}, at: [<ffffffffa0011a04>] usb_deregister_dev+0x37/0x9e [usbcore]
[ 5733.386311]
[ 5733.386312] but task is already holding lock:
[ 5733.386315]  (&hiddev->existancelock){+.+...}, at: [<ffffffffa0094d17>] hiddev_disconnect+0x26/0x87 [usbhid]
[ 5733.386328]
[ 5733.386329] which lock already depends on the new lock.
[ 5733.386330]
[ 5733.386333]
[ 5733.386334] the existing dependency chain (in reverse order) is:
[ 5733.386336]
[ 5733.386337] -> #1 (&hiddev->existancelock){+.+...}:
[ 5733.386346]        [<ffffffff81082d26>] lock_acquire+0xcb/0x10e
[ 5733.386357]        [<ffffffff813df961>] __mutex_lock_common+0x60/0x465
[ 5733.386366]        [<ffffffff813dfe4d>] mutex_lock_nested+0x36/0x3b
[ 5733.386371]        [<ffffffffa0094ad6>] hiddev_open+0x113/0x193 [usbhid]
[ 5733.386378]        [<ffffffffa0011971>] usb_open+0x66/0xc2 [usbcore]
[ 5733.386390]        [<ffffffff8111a8b5>] chrdev_open+0x12b/0x154
[ 5733.386402]        [<ffffffff811159a8>] __dentry_open.isra.16+0x20b/0x355
[ 5733.386408]        [<ffffffff811165dc>] nameidata_to_filp+0x43/0x4a
[ 5733.386413]        [<ffffffff81122ed5>] do_last+0x536/0x570
[ 5733.386419]        [<ffffffff8112300b>] path_openat+0xce/0x301
[ 5733.386423]        [<ffffffff81123327>] do_filp_open+0x33/0x81
[ 5733.386427]        [<ffffffff8111664d>] do_sys_open+0x6a/0xfc
[ 5733.386431]        [<ffffffff811166fb>] sys_open+0x1c/0x1e
[ 5733.386434]        [<ffffffff813e7c79>] system_call_fastpath+0x16/0x1b
[ 5733.386441]
[ 5733.386441] -> #0 (minor_rwsem){++++.+}:
[ 5733.386448]        [<ffffffff8108255d>] __lock_acquire+0xa80/0xd74
[ 5733.386454]        [<ffffffff81082d26>] lock_acquire+0xcb/0x10e
[ 5733.386458]        [<ffffffff813e01f5>] down_write+0x44/0x77
[ 5733.386464]        [<ffffffffa0011a04>] usb_deregister_dev+0x37/0x9e [usbcore]
[ 5733.386475]        [<ffffffffa0094d2d>] hiddev_disconnect+0x3c/0x87 [usbhid]
[ 5733.386483]        [<ffffffff8132df51>] hid_disconnect+0x3f/0x54
[ 5733.386491]        [<ffffffff8132dfb4>] hid_device_remove+0x4e/0x7a
[ 5733.386496]        [<ffffffff812c0957>] __device_release_driver+0x81/0xcd
[ 5733.386502]        [<ffffffff812c09c3>] device_release_driver+0x20/0x2d
[ 5733.386507]        [<ffffffff812c0564>] bus_remove_device+0x114/0x128
[ 5733.386512]        [<ffffffff812bdd6f>] device_del+0x131/0x183
[ 5733.386519]        [<ffffffff8132def3>] hid_destroy_device+0x1e/0x3d
[ 5733.386525]        [<ffffffffa00916b0>] usbhid_disconnect+0x36/0x42 [usbhid]
[ 5733.386530]        [<ffffffffa000fb60>] usb_unbind_interface+0x57/0x11f [usbcore]
[ 5733.386542]        [<ffffffff812c0957>] __device_release_driver+0x81/0xcd
[ 5733.386547]        [<ffffffff812c09c3>] device_release_driver+0x20/0x2d
[ 5733.386552]        [<ffffffff812c0564>] bus_remove_device+0x114/0x128
[ 5733.386557]        [<ffffffff812bdd6f>] device_del+0x131/0x183
[ 5733.386562]        [<ffffffffa000de61>] usb_disable_device+0xa8/0x1d8 [usbcore]
[ 5733.386573]        [<ffffffffa0006bd2>] usb_disconnect+0xab/0x11f [usbcore]
[ 5733.386583]        [<ffffffffa0008aa0>] hub_thread+0x73b/0x1157 [usbcore]
[ 5733.386593]        [<ffffffff8105dc0f>] kthread+0x95/0x9d
[ 5733.386601]        [<ffffffff813e90b4>] kernel_thread_helper+0x4/0x10
[ 5733.386607]
[ 5733.386608] other info that might help us debug this:
[ 5733.386609]
[ 5733.386612]  Possible unsafe locking scenario:
[ 5733.386613]
[ 5733.386615]        CPU0                    CPU1
[ 5733.386618]        ----                    ----
[ 5733.386620]   lock(&hiddev->existancelock);
[ 5733.386625]                                lock(minor_rwsem);
[ 5733.386630]                                lock(&hiddev->existancelock);
[ 5733.386635]   lock(minor_rwsem);
[ 5733.386639]
[ 5733.386640]  *** DEADLOCK ***
[ 5733.386641]
[ 5733.386644] 6 locks held by khubd/186:
[ 5733.386646]  #0:  (&__lockdep_no_validate__){......}, at: [<ffffffffa00084af>] hub_thread+0x14a/0x1157 [usbcore]
[ 5733.386661]  #1:  (&__lockdep_no_validate__){......}, at: [<ffffffffa0006b77>] usb_disconnect+0x50/0x11f [usbcore]
[ 5733.386677]  #2:  (hcd->bandwidth_mutex){+.+.+.}, at: [<ffffffffa0006bc8>] usb_disconnect+0xa1/0x11f [usbcore]
[ 5733.386693]  #3:  (&__lockdep_no_validate__){......}, at: [<ffffffff812c09bb>] device_release_driver+0x18/0x2d
[ 5733.386704]  #4:  (&__lockdep_no_validate__){......}, at: [<ffffffff812c09bb>] device_release_driver+0x18/0x2d
[ 5733.386714]  #5:  (&hiddev->existancelock){+.+...}, at: [<ffffffffa0094d17>] hiddev_disconnect+0x26/0x87 [usbhid]
[ 5733.386727]
[ 5733.386727] stack backtrace:
[ 5733.386731] Pid: 186, comm: khubd Not tainted 3.2.0-custom-next-20120111+ #1
[ 5733.386734] Call Trace:
[ 5733.386741]  [<ffffffff81062881>] ? up+0x34/0x3b
[ 5733.386747]  [<ffffffff813d9ef3>] print_circular_bug+0x1f8/0x209
[ 5733.386752]  [<ffffffff8108255d>] __lock_acquire+0xa80/0xd74
[ 5733.386756]  [<ffffffff810808b4>] ? trace_hardirqs_on_caller+0x15d/0x1a3
[ 5733.386763]  [<ffffffff81043a3f>] ? vprintk+0x3f4/0x419
[ 5733.386774]  [<ffffffffa0011a04>] ? usb_deregister_dev+0x37/0x9e [usbcore]
[ 5733.386779]  [<ffffffff81082d26>] lock_acquire+0xcb/0x10e
[ 5733.386789]  [<ffffffffa0011a04>] ? usb_deregister_dev+0x37/0x9e [usbcore]
[ 5733.386797]  [<ffffffff813e01f5>] down_write+0x44/0x77
[ 5733.386807]  [<ffffffffa0011a04>] ? usb_deregister_dev+0x37/0x9e [usbcore]
[ 5733.386818]  [<ffffffffa0011a04>] usb_deregister_dev+0x37/0x9e [usbcore]
[ 5733.386825]  [<ffffffffa0094d2d>] hiddev_disconnect+0x3c/0x87 [usbhid]
[ 5733.386830]  [<ffffffff8132df51>] hid_disconnect+0x3f/0x54
[ 5733.386834]  [<ffffffff8132dfb4>] hid_device_remove+0x4e/0x7a
[ 5733.386839]  [<ffffffff812c0957>] __device_release_driver+0x81/0xcd
[ 5733.386844]  [<ffffffff812c09c3>] device_release_driver+0x20/0x2d
[ 5733.386848]  [<ffffffff812c0564>] bus_remove_device+0x114/0x128
[ 5733.386854]  [<ffffffff812bdd6f>] device_del+0x131/0x183
[ 5733.386859]  [<ffffffff8132def3>] hid_destroy_device+0x1e/0x3d
[ 5733.386865]  [<ffffffffa00916b0>] usbhid_disconnect+0x36/0x42 [usbhid]
[ 5733.386876]  [<ffffffffa000fb60>] usb_unbind_interface+0x57/0x11f [usbcore]
[ 5733.386882]  [<ffffffff812c0957>] __device_release_driver+0x81/0xcd
[ 5733.386886]  [<ffffffff812c09c3>] device_release_driver+0x20/0x2d
[ 5733.386890]  [<ffffffff812c0564>] bus_remove_device+0x114/0x128
[ 5733.386895]  [<ffffffff812bdd6f>] device_del+0x131/0x183
[ 5733.386905]  [<ffffffffa000de61>] usb_disable_device+0xa8/0x1d8 [usbcore]
[ 5733.386916]  [<ffffffffa0006bd2>] usb_disconnect+0xab/0x11f [usbcore]
[ 5733.386921]  [<ffffffff813dff82>] ? __mutex_unlock_slowpath+0x130/0x141
[ 5733.386929]  [<ffffffffa0008aa0>] hub_thread+0x73b/0x1157 [usbcore]
[ 5733.386935]  [<ffffffff8106a51d>] ? finish_task_switch+0x78/0x150
[ 5733.386941]  [<ffffffff8105e396>] ? __init_waitqueue_head+0x4c/0x4c
[ 5733.386950]  [<ffffffffa0008365>] ? usb_remote_wakeup+0x56/0x56 [usbcore]
[ 5733.386955]  [<ffffffff8105dc0f>] kthread+0x95/0x9d
[ 5733.386961]  [<ffffffff813e90b4>] kernel_thread_helper+0x4/0x10
[ 5733.386966]  [<ffffffff813e24b8>] ? retint_restore_args+0x13/0x13
[ 5733.386970]  [<ffffffff8105db7a>] ? __init_kthread_worker+0x55/0x55
[ 5733.386974]  [<ffffffff813e90b0>] ? gs_change+0x13/0x13

Signed-off-by: Ming Lei <ming.lei@canonical.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2012-02-02 09:48:00 +01:00
Al Viro 2c9ede55ec switch device_get_devnode() and ->devnode() to umode_t *
both callers of device_get_devnode() are only interested in lower 16bits
and nobody tries to return anything wider than 16bit anyway.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-01-03 22:54:55 -05:00
Dan Carpenter 9561f7faa4 HID: hiddev: potential info leak in hiddev_ioctl()
Smatch has a new check for Rosenberg type information leaks where
structs are copied to the user with uninitialized stack data in them.

In this case, the hiddev_devinfo struct has a two byte hole.

struct hiddev_devinfo {
        __u32                      bustype;              /*     0     4 */
        __u32                      busnum;               /*     4     4 */
        __u32                      devnum;               /*     8     4 */
        __u32                      ifnum;                /*    12     4 */
        __s16                      vendor;               /*    16     2 */
        __s16                      product;              /*    18     2 */
        __s16                      version;              /*    20     2 */

        /* XXX 2 bytes hole, try to pack */

        __u32                      num_applications;     /*    24     4 */

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2011-09-27 01:33:10 +02:00
Dan Carpenter 5c699d7d3f HID: hiddev: fix use after free in hiddev_release
There are a couple use after free bugs here.

Signed-off-by: Dan Carpenter <error27@gmail.com>
[jkosina@suse.cz: removed already fixed hunk]
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2011-05-26 14:04:40 +02:00
Jiri Kosina 7f77897ef2 HID: hiddev: fix potential use-after-free
Commit 6cb4b04079 ("HID: hiddev: fix race between hiddev_disconnect
and hiddev_release") made it possible to access hiddev (for unlocking
the existance mutex) once hiddev has been kfreed.

Change the order so that this can not happen (always unlock the mutex first,
it is needed only to protect access to ->exist and ->open).

Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2011-05-24 11:43:18 +02:00
Jiri Kosina 366a2382c6 Merge branches 'doc', 'multitouch', 'upstream' and 'upstream-fixes' into for-linus 2011-05-23 12:49:25 +02:00
Jiri Kosina 6cb4b04079 HID: hiddev: fix race between hiddev_disconnect and hiddev_release
When hiddev_disconnect() runs with chardev open, it will proceed with
usbhid_close(). When userspace in parallel runs the hiddev_release(),
it sees !hiddev->exists (as it has been already set so by
hiddev_disconnect()) and kfrees hiddev while hiddev_disconnect() hasn't
finished yet.

Serialize the access to hiddev->exists and hiddev->open by existancelock.

Reported-by: mike-@cinci.rr.com
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2011-05-20 10:50:13 +02:00
Daniel Mack dd2ed487fd HID: 'name' and 'phys' in 'struct hid_device' can never be NULL
As they are static members of fix size, there is no need to NULL-check them.

Signed-off-by: Daniel Mack <zonque@gmail.com>
Cc: Dmitry Torokhov <dtor@mail.ru>
Cc: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2011-05-18 13:23:31 +02:00
Peter Waechtler 06268b2a38 HID: hiddev: fix error path in hiddev_read when interrupted
hiddev_read: in case mutex_lock_interruptible will be interrupted
remove the task from the wait queue.

Signed-off-by: Peter Waechtler <pwaechtler@mac.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2011-04-29 13:53:53 +02:00
Dan Carpenter ac065bf214 HID: hiddev: fix brace indent
There was an extra tab so the close curly brace didn't match up with
the right if statement.

Signed-off-by: Dan Carpenter <error27@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2011-03-27 11:14:40 +02:00
Jiri Kosina 2ade0c1d9d Merge branch 'master' into upstream 2010-12-10 15:19:18 +01:00
Joe Perches 4291ee305e HID: Add and use hid_<level>: dev_<level> equivalents
Neaten current uses of dev_<level> by adding and using
hid specific hid_<level> macros.

Convert existing uses of dev_<level> uses to hid_<level>.
Convert hid-pidff printk uses to hid_<level>.

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_<level> 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 <joe@perches.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2010-12-10 15:10:38 +01:00
Valentine Barshak 33d6eb570b HID: Consolidate device existence checks in hiddev_ioctl
Currently, if the device has been removed before hiddev_ioctl(),
the -EIO is returned. If it's removed while hiddev_ioctl() is in
progress, some commands are still processed fine, others
return -ENODEV. This change takes the "existancelock" before
processing ioctl commands and releases it at the end.
If the device has been removed, always returns -ENODEV.

Signed-off-by: Valentine Barshak <vbarshak@mvista.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2010-12-07 15:45:50 +01:00
Valentine Barshak 1a8e8fab79 HID: Fix race between disconnect and hiddev_ioctl
A USB HID device can be disconnected at any time.
If this happens right before or while hiddev_ioctl is in progress,
the hiddev_ioctl tries to access invalid hiddev->hid pointer.
When the hid device is disconnected, the hiddev_disconnect()
ends up with a call to hid_device_release() which frees
hid_device, but doesn't set the hiddev->hid pointer to NULL.
If the deallocated memory region has been re-used by the kernel,
this can cause a crash or memory corruption.

Since disconnect can happen at any time, we can't initialize
struct hid_device *hid = hiddev->hid at the beginning of ioctl
and then use it.

This change checks hiddev->exist flag while holding
the existancelock and uses hid_device only if it exists.

Signed-off-by: Valentine Barshak <vbarshak@mvista.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2010-12-07 15:45:49 +01:00
Arnd Bergmann 451a3c24b0 BKL: remove extraneous #include <smp_lock.h>
The big kernel lock has been removed from all these files at some point,
leaving only the #include.

Remove this too as a cleanup.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-11-17 08:59:32 -08:00
Jiri Kosina c3d9d74336 Merge branches 'upstream' and 'upstream-fixes' into for-linus 2010-10-23 22:44:36 +02:00
Linus Torvalds 092e0e7e52 Merge branch 'llseek' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bkl
* 'llseek' of git://git.kernel.org/pub/scm/linux/kernel/git/arnd/bkl:
  vfs: make no_llseek the default
  vfs: don't use BKL in default_llseek
  llseek: automatically add .llseek fop
  libfs: use generic_file_llseek for simple_attr
  mac80211: disallow seeks in minstrel debug code
  lirc: make chardev nonseekable
  viotape: use noop_llseek
  raw: use explicit llseek file operations
  ibmasmfs: use generic_file_llseek
  spufs: use llseek in all file operations
  arm/omap: use generic_file_llseek in iommu_debug
  lkdtm: use generic_file_llseek in debugfs
  net/wireless: use generic_file_llseek in debugfs
  drm: use noop_llseek
2010-10-22 10:52:56 -07:00
Arnd Bergmann 6038f373a3 llseek: automatically add .llseek fop
All file_operations should get a .llseek operation so we can make
nonseekable_open the default for future file operations without a
.llseek pointer.

The three cases that we can automatically detect are no_llseek, seq_lseek
and default_llseek. For cases where we can we can automatically prove that
the file offset is always ignored, we use noop_llseek, which maintains
the current behavior of not returning an error from a seek.

New drivers should normally not use noop_llseek but instead use no_llseek
and call nonseekable_open at open time.  Existing drivers can be converted
to do the same when the maintainer knows for certain that no user code
relies on calling seek on the device file.

The generated code is often incorrectly indented and right now contains
comments that clarify for each added line why a specific variant was
chosen. In the version that gets submitted upstream, the comments will
be gone and I will manually fix the indentation, because there does not
seem to be a way to do that using coccinelle.

Some amount of new code is currently sitting in linux-next that should get
the same modifications, which I will do at the end of the merge window.

Many thanks to Julia Lawall for helping me learn to write a semantic
patch that does all this.

===== begin semantic patch =====
// This adds an llseek= method to all file operations,
// as a preparation for making no_llseek the default.
//
// The rules are
// - use no_llseek explicitly if we do nonseekable_open
// - use seq_lseek for sequential files
// - use default_llseek if we know we access f_pos
// - use noop_llseek if we know we don't access f_pos,
//   but we still want to allow users to call lseek
//
@ open1 exists @
identifier nested_open;
@@
nested_open(...)
{
<+...
nonseekable_open(...)
...+>
}

@ open exists@
identifier open_f;
identifier i, f;
identifier open1.nested_open;
@@
int open_f(struct inode *i, struct file *f)
{
<+...
(
nonseekable_open(...)
|
nested_open(...)
)
...+>
}

@ read disable optional_qualifier exists @
identifier read_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
expression E;
identifier func;
@@
ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off)
{
<+...
(
   *off = E
|
   *off += E
|
   func(..., off, ...)
|
   E = *off
)
...+>
}

@ read_no_fpos disable optional_qualifier exists @
identifier read_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
@@
ssize_t read_f(struct file *f, char *p, size_t s, loff_t *off)
{
... when != off
}

@ write @
identifier write_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
expression E;
identifier func;
@@
ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off)
{
<+...
(
  *off = E
|
  *off += E
|
  func(..., off, ...)
|
  E = *off
)
...+>
}

@ write_no_fpos @
identifier write_f;
identifier f, p, s, off;
type ssize_t, size_t, loff_t;
@@
ssize_t write_f(struct file *f, const char *p, size_t s, loff_t *off)
{
... when != off
}

@ fops0 @
identifier fops;
@@
struct file_operations fops = {
 ...
};

@ has_llseek depends on fops0 @
identifier fops0.fops;
identifier llseek_f;
@@
struct file_operations fops = {
...
 .llseek = llseek_f,
...
};

@ has_read depends on fops0 @
identifier fops0.fops;
identifier read_f;
@@
struct file_operations fops = {
...
 .read = read_f,
...
};

@ has_write depends on fops0 @
identifier fops0.fops;
identifier write_f;
@@
struct file_operations fops = {
...
 .write = write_f,
...
};

@ has_open depends on fops0 @
identifier fops0.fops;
identifier open_f;
@@
struct file_operations fops = {
...
 .open = open_f,
...
};

// use no_llseek if we call nonseekable_open
////////////////////////////////////////////
@ nonseekable1 depends on !has_llseek && has_open @
identifier fops0.fops;
identifier nso ~= "nonseekable_open";
@@
struct file_operations fops = {
...  .open = nso, ...
+.llseek = no_llseek, /* nonseekable */
};

@ nonseekable2 depends on !has_llseek @
identifier fops0.fops;
identifier open.open_f;
@@
struct file_operations fops = {
...  .open = open_f, ...
+.llseek = no_llseek, /* open uses nonseekable */
};

// use seq_lseek for sequential files
/////////////////////////////////////
@ seq depends on !has_llseek @
identifier fops0.fops;
identifier sr ~= "seq_read";
@@
struct file_operations fops = {
...  .read = sr, ...
+.llseek = seq_lseek, /* we have seq_read */
};

// use default_llseek if there is a readdir
///////////////////////////////////////////
@ fops1 depends on !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier readdir_e;
@@
// any other fop is used that changes pos
struct file_operations fops = {
... .readdir = readdir_e, ...
+.llseek = default_llseek, /* readdir is present */
};

// use default_llseek if at least one of read/write touches f_pos
/////////////////////////////////////////////////////////////////
@ fops2 depends on !fops1 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier read.read_f;
@@
// read fops use offset
struct file_operations fops = {
... .read = read_f, ...
+.llseek = default_llseek, /* read accesses f_pos */
};

@ fops3 depends on !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier write.write_f;
@@
// write fops use offset
struct file_operations fops = {
... .write = write_f, ...
+	.llseek = default_llseek, /* write accesses f_pos */
};

// Use noop_llseek if neither read nor write accesses f_pos
///////////////////////////////////////////////////////////

@ fops4 depends on !fops1 && !fops2 && !fops3 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier read_no_fpos.read_f;
identifier write_no_fpos.write_f;
@@
// write fops use offset
struct file_operations fops = {
...
 .write = write_f,
 .read = read_f,
...
+.llseek = noop_llseek, /* read and write both use no f_pos */
};

@ depends on has_write && !has_read && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier write_no_fpos.write_f;
@@
struct file_operations fops = {
... .write = write_f, ...
+.llseek = noop_llseek, /* write uses no f_pos */
};

@ depends on has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
identifier read_no_fpos.read_f;
@@
struct file_operations fops = {
... .read = read_f, ...
+.llseek = noop_llseek, /* read uses no f_pos */
};

@ depends on !has_read && !has_write && !fops1 && !fops2 && !has_llseek && !nonseekable1 && !nonseekable2 && !seq @
identifier fops0.fops;
@@
struct file_operations fops = {
...
+.llseek = noop_llseek, /* no read or write fn */
};
===== End semantic patch =====

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Julia Lawall <julia@diku.dk>
Cc: Christoph Hellwig <hch@infradead.org>
2010-10-15 15:53:27 +02:00
Alan Stern 50bb6d8492 HID: usbhid: remove unused hiddev_driver
Now that hiddev_driver isn't being used for anything, there's no
reason to keep it around.  This patch (as1419) gets rid of it
entirely.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2010-09-24 14:03:44 +02:00
Guillaume Chazarain 8fe294caf8 HID: fix hiddev's use of usb_find_interface
My macbook infrared remote control was broken by commit
bd25f4dd69 ("HID: hiddev: use
usb_find_interface, get rid of BKL").

This device appears in dmesg as:
apple 0003:05AC:8242.0001: hiddev0,hidraw0: USB HID v1.11 Device
[Apple Computer, Inc. IR Receiver] on usb-0000:00:1d.2-1/input0

It stopped working as lircd was getting ENODEV when opening /dev/usb/hiddev0.

AFAICS hiddev_driver is a dummy driver so usb_find_interface(&hiddev_driver)
does not find anything.

The device is associated with the usbhid driver, so let's do
usb_find_interface(&hid_driver) instead.

$ ls -l /sys/devices/pci0000:00/0000:00:1d.2/usb7/7-1/7-1:1.0/usb/hiddev0/device/driver
lrwxrwxrwx 1 root root 0 2010-09-12 16:28 /sys/devices/pci0000:00/0000:00:1d.2/usb7/7-1/7-1:1.0/usb/hiddev0/device/driver -> ../../../../../../bus/usb/drivers/usbhid

Signed-off-by: Guillaume Chazarain <guichaz@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2010-09-14 10:58:42 +02:00
Jiri Kosina 9c9e54a8df HID: hiddev: fix memory corruption due to invalid intfdata
Commit bd25f4dd69 ("HID: hiddev: use usb_find_interface,
get rid of BKL") introduced using of private intfdata in hiddev for
purpose of storing hiddev pointer.

This is a problem, because intf pointer is already being set to struct
hid_device pointer by HID core. This obviously lead to memory corruptions
at device disconnect time, such as

WARNING: at lib/kobject.c:595 kobject_put+0x37/0x4b()
kobject: '(null)' (ffff88011e9cd898): is not initialized, yet kobject_put() is being called.

Convert hiddev into accessing hiddev through struct hid_device which is
in intfdata already.

Reported-and-tested-by: Markus Trippelsdorf <markus@trippelsdorf.de>
Reported-and-tested-by: Heinz Diehl <htd@fritha.org>
Reported-and-tested-by: Alan Ott <alan@signal11.us>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2010-08-13 12:19:45 +02:00
Chris Ball 7032269e87 HID: hiddev: protect against disconnect/NULL-dereference race
One of our users reports consistently hitting a NULL dereference that
resolves to the "hid_to_usb_dev(hid);" call in hiddev_ioctl(), when
disconnecting a Lego WeDo USB HID device from an OLPC XO running
Scratch software.  There's a FIXME comment and a guard against the
dereference, but that happens farther down the function than the
initial dereference does.

This patch moves the call to be below the guard, and the user reports
that it fixes the problem for him.  OLPC bug report:
http://dev.laptop.org/ticket/10174

Signed-off-by: Chris Ball <cjb@laptop.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2010-08-13 11:19:24 +02:00
Arnd Bergmann bd25f4dd69 HID: hiddev: use usb_find_interface, get rid of BKL
This removes the private hiddev_table in the usbhid
driver and changes it to use usb_find_interface
instead.

The advantage is that we can avoid the race between
usb_register_dev and usb_open and no longer need the
big kernel lock.

This doesn't introduce race condition -- the intf pointer could be
invalidated only in hiddev_disconnect() through usb_deregister_dev(),
but that will block on minor_rwsem and not actually remove the device
until usb_open().

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Cc: Jiri Kosina <jkosina@suse.cz>
Cc: "Greg Kroah-Hartman" <gregkh@suse.de>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2010-07-13 23:56:30 +02:00
Jiri Kosina da54a0ced4 HID: update BKL comment in hiddev
Update comment explaining BKL usage in legacy hiddev driver.

Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2010-03-30 10:16:33 +02:00
Oliver Neukum 86266452f8 USB: Push BKL on open down into the drivers
Straightforward push into the drivers to allow
auditing individual drivers separately

Signed-off-by: Oliver Neukum <oliver@neukum.org>
Acked-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Cc: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2010-03-02 14:54:23 -08:00
Jiri Kosina 6c85773043 HID: remove BKL from hiddev_ioctl_usage()
The race between ioctl and disconnect is guarded by low level
hiddev device mutex (existancelock) since the commit
07903407 ("HID: hiddev cleanup -- handle all error conditions
properly"), therefore we can remove the lock_kernel() from
hiddev_ioctl_usage().

Acked-by: Oliver Neukum <oliver@neukum.org>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2009-11-05 18:59:03 +01:00
Kay Sievers e454cea20b Driver-Core: extend devnode callbacks to provide permissions
This allows subsytems to provide devtmpfs with non-default permissions
for the device node. Instead of the default mode of 0600, null, zero,
random, urandom, full, tty, ptmx now have a mode of 0666, which allows
non-privileged processes to access standard device nodes in case no
other userspace process applies the expected permissions.

This also fixes a wrong assignment in pktcdvd and a checkpatch.pl complain.

Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-09-19 12:50:38 -07:00
Jiri Kosina affbb8c6e6 HID: support larger reports than 64 bytes in hiddev
hiddev userspace driver uses a rignbuffer to store the parsed usages
that should be returned through read(). This buffer is 64 bytes long,
which is sufficient for queueing single USB 1.0 low-speed report, which
is of maximum size 48 bytes.

There are however USB HID devices which are full-speed USB devices, and
therefore they are free to produce reports 64 bytes long. This is correctly
handled by HID core, but read() on hiddev node gets stuck forever, because
the ring buffer loops infinitely (as it is exactly 64 bytes long as well),
never advancing the buffer pointer.

Plus, the core driver is ready to handle highspeed devices, so we should be
able to handle reports from such devices in the hiddev driver as well, which
means we need larger ringbuffer.

Reported-by: Michael Zeisel <michael.zeisel@philips.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2009-08-20 12:04:14 +02:00
Linus Torvalds 1fd1f28536 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/hid
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/hid:
  HID: Move dereferences below a NULL test
  HID: hiddev, fix lock imbalance
2009-07-22 09:30:07 -07:00
Jiri Slaby 4859484b09 HID: hiddev, fix lock imbalance
Add omitted BKL to one switch/case.

Cc: Stable <stable@kernel.org>
Signed-off-by: Jiri Slaby <jirislaby@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2009-06-22 11:01:06 +02:00
Kay Sievers f7a386c5b8 Driver Core: usb: add nodename support for usb drivers.
This adds support for USB drivers to report their requested nodename to
userspace.  It also updates a number of USB drivers to provide the
needed subdirectory and device name to be used for them.

Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Jan Blunck <jblunck@suse.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
2009-06-15 21:30:25 -07:00
Jiri Kosina 621de59308 Merge branch 'autosuspend' into for-next
Conflicts:

	drivers/hid/hid-core.c
2009-03-30 15:14:53 +02:00
Oliver Neukum e43bd67d72 HID: fix race between usb_register_dev() and hiddev_open()
upon further thought this code is still racy.

	retval = usb_register_dev(usbhid->intf, &hiddev_class);

here you open a window during which open can happen

	if (retval) {
		err_hid("Not able to get a minor for this device.");
		hid->hiddev = NULL;
		kfree(hiddev);
		return -1;
	} else {
		hid->minor = usbhid->intf->minor;
		hiddev_table[usbhid->intf->minor - HIDDEV_MINOR_BASE] = hiddev;

and will fail because hiddev_table hasn't been updated

The obvious fix of using a mutex to guard hiddev_table doesn't work because
usb_open() and usb_register_dev() take minor_rwsem and we'd have an AB-BA
deadlock. We need a lock usb_open() also takes in the right order and that leaves
only one option, BKL. I don't like it but I see no alternative.

Once the usb_open() implements something better than lock_kernel(), we could also
do so.

Signed-off-by: Oliver Neukum <oneukum@suse.de>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2009-03-30 15:12:52 +02:00