Silences the following warnings:
drivers/usb/gadget/function/f_fs.c:1253:37: warning: incorrect type in argument 1 (different address spaces)
drivers/usb/gadget/function/f_fs.c:1253:37:    expected void [noderef] <asn:1>*to
drivers/usb/gadget/function/f_fs.c:1253:37:    got void *<noident>
drivers/usb/gadget/function/f_fs.c:2322:23: warning: cast to restricted __le32
drivers/usb/gadget/function/f_fs.c:2876:38: warning: cast to restricted __le32
drivers/usb/gadget/function/f_fs.c:272:12: warning: context imbalance in '__ffs_ep0_queue_wait' - unexpected unlock
drivers/usb/gadget/function/f_fs.c:450:17: warning: context imbalance in 'ffs_ep0_write' - different lock contexts for basic block
drivers/usb/gadget/function/f_fs.c:490:24: warning: context imbalance in '__ffs_ep0_read_events' - unexpected unlock
drivers/usb/gadget/function/f_fs.c:496:16: warning: context imbalance in 'ffs_ep0_read' - different lock contexts for basic block

Also, add an "unlocks spinlock" comment for consistency with existing ones.
No behaviour change is intended.
Signed-off-by: NVincent Pelletier <plr.vincent@gmail.com>
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

The specification says that the Reserved1 field in OS_DESC_EXT_COMPAT
must have the value "1", but when this feature was first implemented we
rejected any non-zero values.

This was adjusted to accept all non-zero values (while now rejecting
zero) in commit 53642399 ("usb: gadget: f_fs: Fix wrong check on
reserved1 of OS_DESC_EXT_COMPAT"), but that breaks any userspace
programs that worked previously by returning EINVAL when Reserved1 == 0
which was previously the only value that succeeded!

If we just set the field to "1" ourselves, both old and new userspace
programs continue to work correctly and, as a bonus, old programs are
now compliant with the specification without having to fix anything
themselves.

Fixes: 53642399 ("usb: gadget: f_fs: Fix wrong check on reserved1 of OS_DESC_EXT_COMPAT")
Cc: <stable@vger.kernel.org>
Signed-off-by: NJohn Keeping <john@metanate.com>
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

Found using DEBUG_ATOMIC_SLEEP while submitting an AIO read operation:

[  100.853642] BUG: sleeping function called from invalid context at mm/slab.h:421
[  100.861148] in_atomic(): 1, irqs_disabled(): 1, pid: 1880, name: python
[  100.867954] 2 locks held by python/1880:
[  100.867961]  #0:  (&epfile->mutex){....}, at: [<f8188627>] ffs_mutex_lock+0x27/0x30 [usb_f_fs]
[  100.868020]  #1:  (&(&ffs->eps_lock)->rlock){....}, at: [<f818ad4b>] ffs_epfile_io.isra.17+0x24b/0x590 [usb_f_fs]
[  100.868076] CPU: 1 PID: 1880 Comm: python Not tainted 4.14.0-edison+ #118
[  100.868085] Hardware name: Intel Corporation Merrifield/BODEGA BAY, BIOS 542 2015.01.21:18.19.48
[  100.868093] Call Trace:
[  100.868122]  dump_stack+0x47/0x62
[  100.868156]  ___might_sleep+0xfd/0x110
[  100.868182]  __might_sleep+0x68/0x70
[  100.868217]  kmem_cache_alloc_trace+0x4b/0x200
[  100.868248]  ? dwc3_gadget_ep_alloc_request+0x24/0xe0 [dwc3]
[  100.868302]  dwc3_gadget_ep_alloc_request+0x24/0xe0 [dwc3]
[  100.868343]  usb_ep_alloc_request+0x16/0xc0 [udc_core]
[  100.868386]  ffs_epfile_io.isra.17+0x444/0x590 [usb_f_fs]
[  100.868424]  ? _raw_spin_unlock_irqrestore+0x27/0x40
[  100.868457]  ? kiocb_set_cancel_fn+0x57/0x60
[  100.868477]  ? ffs_ep0_poll+0xc0/0xc0 [usb_f_fs]
[  100.868512]  ffs_epfile_read_iter+0xfe/0x157 [usb_f_fs]
[  100.868551]  ? security_file_permission+0x9c/0xd0
[  100.868587]  ? rw_verify_area+0xac/0x120
[  100.868633]  aio_read+0x9d/0x100
[  100.868692]  ? __fget+0xa2/0xd0
[  100.868727]  ? __might_sleep+0x68/0x70
[  100.868763]  SyS_io_submit+0x471/0x680
[  100.868878]  do_int80_syscall_32+0x4e/0xd0
[  100.868921]  entry_INT80_32+0x2a/0x2a
[  100.868932] EIP: 0xb7fbb676
[  100.868941] EFLAGS: 00000292 CPU: 1
[  100.868951] EAX: ffffffda EBX: b7aa2000 ECX: 00000002 EDX: b7af8368
[  100.868961] ESI: b7fbb660 EDI: b7aab000 EBP: bfb6c658 ESP: bfb6c638
[  100.868973]  DS: 007b ES: 007b FS: 0000 GS: 0033 SS: 007b
Signed-off-by: NVincent Pelletier <plr.vincent@gmail.com>
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

KASAN enabled configuration reports an error

BUG: KASAN: use-after-free in ffs_free_inst+... [usb_f_fs] at addr ...
Write of size 8 by task ...

This is observed after "ffs-test" is run and interrupted. If after that
functionfs is unmounted and g_ffs module is unloaded, that use-after-free
occurs during g_ffs module removal.

Although the report indicates ffs_free_inst() function, the actual
use-after-free condition occurs in _ffs_free_dev() function, which
is probably inlined into ffs_free_inst().

This happens due to keeping the ffs_data reference in device structure
during functionfs unmounting, while ffs_data itself is freed as no longer
needed. The fix is to clear that reference in ffs_closed() function,
which is a counterpart of ffs_ready(), where the reference is stored.

Fixes: 3262ad82 ("usb: gadget: f_fs: Stop ffs_closed NULL pointer dereference")
Cc: stable@vger.kernel.org
Signed-off-by: NAndrew Gabbasov <andrew_gabbasov@mentor.com>
Acked-by: NFelipe Balbi <felipe.balbi@linux.intel.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Now that the SPDX tag is in all USB files, that identifies the license
in a specific and legally-defined manner.  So the extra GPL text wording
can be removed as it is no longer needed at all.

This is done on a quest to remove the 700+ different ways that files in
the kernel describe the GPL license text.  And there's unneeded stuff
like the address (sometimes incorrect) for the FSF which is never
needed.

No copyright headers or other non-license-description text was removed.

Cc: Oliver Neukum <oneukum@suse.com>
Cc: Johan Hovold <johan@kernel.org>
Cc: Jerry Zhang <zhangjerry@google.com>
Cc: John Keeping <john@metanate.com>
Cc: Krzysztof Opasiak <k.opasiak@samsung.com>
Cc: Abdulhadi Mohamed <abdulahhadi2@gmail.com>
Cc: Matthew Wilcox <willy@linux.intel.com>
Cc: Janusz Dziedzic <januszx.dziedzic@linux.intel.com>
Acked-by: NFelipe Balbi <felipe.balbi@linux.intel.com>
Acked-by: NMichal Nazarewicz <mina86@mina86.com>
Acked-by: NLaurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: NVincent Pelletier <plr.vincent@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

It's good to have SPDX identifiers in all files to make it easier to
audit the kernel tree for correct licenses.

Update the drivers/usb/ and include/linux/usb* files with the correct
SPDX license identifier based on the license text in the file itself.
The SPDX identifier is a legally binding shorthand, which can be used
instead of the full boiler plate text.

This work is based on a script and data from Thomas Gleixner, Philippe
Ombredanne, and Kate Stewart.

Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Kate Stewart <kstewart@linuxfoundation.org>
Cc: Philippe Ombredanne <pombredanne@nexb.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: NFelipe Balbi <felipe.balbi@linux.intel.com>
Acked-by: NJohan Hovold <johan@kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Make these structures const as they are only passed to the const
argument of the functions config_{group/item}_init_type_name.
Signed-off-by: NBhumika Goyal <bhumirks@gmail.com>
Acked-by: NFelipe Balbi <felipe.balbi@linux.intel.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>

By submitting completed transfers to the system workqueue there is no
guarantee that completion events will be queued up in the correct order,
as in multi-processor systems there is a thread running for each
processor and the work items are not bound to a particular core.

This means that several completions are in the queue at the same time,
they may be processed in parallel and complete out of order, resulting
in data appearing corrupt when read by userspace.

Create a single-threaded workqueue for FunctionFS so that data completed
requests is passed to userspace in the order in which they complete.
Acked-by: NMichal Nazarewicz <mina86@mina86.com>
Signed-off-by: NJohn Keeping <john@metanate.com>
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

Users can apply i/o in the wrong direction on an
endpoint to stall it. In case there is an error
that does not allow the endpoint to be stalled,
we want the user to know.

An operation to stall the endpoint will return
EBADMSG if successful, EAGAIN if there are still
queued requests, and other errors depending on
the underlying implementation.

Also remove the conditional since it is always true.
Acked-by: NMichal Nazarewicz <mina86@mina86.com>
Signed-off-by: NJerry Zhang <zhangjerry@google.com>
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

There were individual waitqueues for each epfile but eps_enable
would iterate through all of them, resulting in essentially the
same wakeup time.

The waitqueue represents the function being enabled, so a central
waitqueue in ffs_data makes more sense and is less redundant.

Also use wake_up_interruptible to reflect use of
wait_event_interruptible.
Acked-by: NMichal Nazarewicz <mina86@mina86.com>
Signed-off-by: NJerry Zhang <zhangjerry@google.com>
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

This allows users to make an ioctl call as the first action on a
connection. Ex, some functions might want to get endpoint size
before making any i/os.

Previously, calling ioctls before read/write would depending on the
timing of endpoints being enabled.

ESHUTDOWN is now a possible return value and ENODEV is not, so change
docs accordingly.
Acked-by: NMichal Nazarewicz <mina86@mina86.com>
Signed-off-by: NJerry Zhang <zhangjerry@google.com>
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

Companion descriptor is only used for SuperSpeed endpoints,
if the endpoints are HighSpeed or FullSpeed, the Companion
descriptor will not allocated, so we can only access it if
gadget is SuperSpeed.

I can reproduce this issue on Rockchip platform rk3368 SoC
which supports USB 2.0, and use functionfs for ADB. Kernel
build with CONFIG_KASAN=y and CONFIG_SLUB_DEBUG=y report
the following BUG:

==================================================================
BUG: KASAN: slab-out-of-bounds in ffs_func_set_alt+0x224/0x3a0 at addr ffffffc0601f6509
Read of size 1 by task swapper/0/0
============================================================================
BUG kmalloc-256 (Not tainted): kasan: bad access detected
----------------------------------------------------------------------------

Disabling lock debugging due to kernel taint
INFO: Allocated in ffs_func_bind+0x52c/0x99c age=1275 cpu=0 pid=1
alloc_debug_processing+0x128/0x17c
___slab_alloc.constprop.58+0x50c/0x610
__slab_alloc.isra.55.constprop.57+0x24/0x34
__kmalloc+0xe0/0x250
ffs_func_bind+0x52c/0x99c
usb_add_function+0xd8/0x1d4
configfs_composite_bind+0x48c/0x570
udc_bind_to_driver+0x6c/0x170
usb_udc_attach_driver+0xa4/0xd0
gadget_dev_desc_UDC_store+0xcc/0x118
configfs_write_file+0x1a0/0x1f8
__vfs_write+0x64/0x174
vfs_write+0xe4/0x200
SyS_write+0x68/0xc8
el0_svc_naked+0x24/0x28
INFO: Freed in inode_doinit_with_dentry+0x3f0/0x7c4 age=1275 cpu=7 pid=247
...
Call trace:
[<ffffff900808aab4>] dump_backtrace+0x0/0x230
[<ffffff900808acf8>] show_stack+0x14/0x1c
[<ffffff90084ad420>] dump_stack+0xa0/0xc8
[<ffffff90082157cc>] print_trailer+0x188/0x198
[<ffffff9008215948>] object_err+0x3c/0x4c
[<ffffff900821b5ac>] kasan_report+0x324/0x4dc
[<ffffff900821aa38>] __asan_load1+0x24/0x50
[<ffffff90089eb750>] ffs_func_set_alt+0x224/0x3a0
[<ffffff90089d3760>] composite_setup+0xdcc/0x1ac8
[<ffffff90089d7394>] android_setup+0x124/0x1a0
[<ffffff90089acd18>] _setup+0x54/0x74
[<ffffff90089b6b98>] handle_ep0+0x3288/0x4390
[<ffffff90089b9b44>] dwc_otg_pcd_handle_out_ep_intr+0x14dc/0x2ae4
[<ffffff90089be85c>] dwc_otg_pcd_handle_intr+0x1ec/0x298
[<ffffff90089ad680>] dwc_otg_pcd_irq+0x10/0x20
[<ffffff9008116328>] handle_irq_event_percpu+0x124/0x3ac
[<ffffff9008116610>] handle_irq_event+0x60/0xa0
[<ffffff900811af30>] handle_fasteoi_irq+0x10c/0x1d4
[<ffffff9008115568>] generic_handle_irq+0x30/0x40
[<ffffff90081159b4>] __handle_domain_irq+0xac/0xdc
[<ffffff9008080e9c>] gic_handle_irq+0x64/0xa4
...
Memory state around the buggy address:
  ffffffc0601f6400: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  ffffffc0601f6480: 00 00 00 00 00 00 00 00 00 00 06 fc fc fc fc fc
 >ffffffc0601f6500: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                       ^
  ffffffc0601f6580: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
  ffffffc0601f6600: fc fc fc fc fc fc fc fc 00 00 00 00 00 00 00 00
==================================================================
Signed-off-by: NWilliam Wu <william.wu@rock-chips.com>
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

Currently ffs_dev::name can be either allocated by the client of
the ffs_dev structure or by the f_fs.c core itself.  The former
is used by g_ffs while the latter happens with configfs.

Historically, g_ffs did not need to allocate separate buffer for
the name so what is now f_fs.c core never cared about freeing
that space.  With configfs the name needs to be copied since the
memory is not guaranteed to be availeble after ffs_set_inst_name
finishes.

The complication is therefore here to avoid allocations in the
g_ffs case but it complicates the code inproportinally to
benefits it provides.  In particular, g_ffs is considered
‘legacy’ so optimising for its sake is unlikely to be worth the
effort.

With that observation in mind, simplify the code by unifying the
code paths in g_ffs and configfs paths.  Furthermore, instead of
allocating a new buffer for the name, simply embed it in the
ffs_dev structure.  This further makes the memory management
less convoluted and error-prone.

The configfs interface for functionfs imposed a limit of 40
characters for the name so this results in a 41-byte buffer
added to the structure.  (For short names this may lead to
wasted memory but the actual amount is not immediately obvious
and depends on pointer size and which slab buckets the structure
and name would fall into).
Signed-off-by: NMichal Nazarewicz <mina86@mina86.com>
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

refcount_t type and corresponding API should be
used instead of atomic_t when the variable is used as
a reference counter. This allows to avoid accidental
refcounter overflows that might lead to use-after-free
situations.
Signed-off-by: NElena Reshetova <elena.reshetova@intel.com>
Signed-off-by: NHans Liljestrand <ishkamiel@gmail.com>
Signed-off-by: NKees Cook <keescook@chromium.org>
Signed-off-by: NDavid Windsor <dwindsor@gmail.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

This reverts commit ac670a3a650b899fc020b81f63e810d06015b865.

This introduce bug we already fixed in
commit 53642399 ("usb: gadget: f_fs: Fix wrong check on reserved1 wof OS_DESC_EXT_COMPAT")

Next FFS (adb) SS enumeration fail with Windows OS.
Signed-off-by: NJanusz Dziedzic <januszx.dziedzic@linux.intel.com>
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

If we're dealing with SuperSpeed endpoints, we need
to make sure to pass along the companion descriptor
and initialize fields needed by the Gadget
API. Eventually, f_fs.c should be converted to use
config_ep_by_speed() like all other functions,
though.

Cc: <stable@vger.kernel.org>
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

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: NLinus 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: NIngo Molnar <mingo@kernel.org>

OS descriptor head, when flagged as provided, is accessed without
checking if it fits in provided buffer. Verify length before access.
Also, there are other places where buffer length it checked
after accessing offsets which are potentially past the end. Check
buffer length before as well to fail cleanly.
Signed-off-by: NVincent Pelletier <plr.vincent@gmail.com>
Acked-by: NFelipe Balbi <felipe.balbi@linux.intel.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

It is allowed by the USB specification to enabled same-address, opposite-
direction endpoints simultaneously, which means 30 non-zero endpoints
are allowed. So double eps_addrmap length to 30.
The original code only accepted 14 descriptors out of a likely intended 15
(as there are 15 endpoint addresses, ignoring direction), because the first
eps_addrmap entry is unused (it is a placeholder for endpoint zero). So
increase eps_addrmap length by one to 31.
Signed-off-by: NVincent Pelletier <plr.vincent@gmail.com>
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

Endpoint descriptors come in 2 sizes, struct usb_endpoint_descriptor being
the largest. Use bLength to stop on endpoint descriptor boundary, and not
2 bytes too far.
Signed-off-by: NVincent Pelletier <plr.vincent@gmail.com>
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

Since we need to change the implementation, stop exposing internals.

Provide kref_read() to read the current reference count; typically
used for debug messages.

Kills two anti-patterns:

	atomic_read(&kref->refcount)
	kref->refcount.counter
Signed-off-by: NPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: NIngo Molnar <mingo@kernel.org>

When zero endpoints are declared for a function, there is no endpoint
to disable, enable or free, so replace do...while loops with while loops.
Change pre-decrement to post-decrement to iterate the same number of times
when there are endpoints to process.
Signed-off-by: NVincent Pelletier <plr.vincent@gmail.com>
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

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
Acked-by: NMichal Nazarewicz <mina86@mina86.com>
Signed-off-by: NBaolin Wang <baolin.wang@linaro.org>
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

Reserved1 is documented as expected to be set to 0, but this test fails
when it it set to 0. Reverse the condition.
Signed-off-by: NVincent Pelletier <plr.vincent@gmail.com>
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

When FUNCTIONFS_EVENTFD flag is set, __ffs_data_got_descs reads a 32bits,
little-endian value right after the fixed structure header, and passes it
to eventfd_ctx_fdget. Document this.

Also, rephrase a comment to be affirmative about the role of string
descriptor at index 0. Ref: USB 2.0 spec paragraph "9.6.7 String", and
also checked to still be current in USB 3.0 spec paragraph "9.6.9 String".
Signed-off-by: NVincent Pelletier <plr.vincent@gmail.com>
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

copy_from_iter_full(), copy_from_iter_full_nocache() and
csum_and_copy_from_iter_full() - counterparts of copy_from_iter()
et.al., advancing iterator only in case of successful full copy
and returning whether it had been successful or not.

Convert some obvious users.  *NOTE* - do not blindly assume that
something is a good candidate for those unless you are sure that
not advancing iov_iter in failure case is the right thing in
this case.  Anything that does short read/short write kind of
stuff (or is in a loop, etc.) is unlikely to be a good one.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Properly check the return code of ffs_func_revmap_intf() and
ffs_func_revmap_ep() for a non-negative value.

Instead of checking the return code, the comparison was performed for the last
parameter of the function calls, because of wrong parenthesis.

This also fixes the following static checker warning:
drivers/usb/gadget/function/f_fs.c:3152 ffs_func_req_match()
warn: always true condition '(((creq->wIndex)) >= 0) => (0-u16max >= 0)'
Reported-by: NDan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: NFelix Hädicke <felixhaedicke@web.de>
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

There is only one waiter for the completion, therefore there
is no need to use complete_all(). Let's make that clear by
using complete() instead of complete_all().

The usage pattern of the completion is:

waiter context                          waker context
  reinit_completion()
  usb_esp_queue()
  wait_for_completion_interruptible()

					ffs_ep0_complete()
					  complete()
Acked-by: NMichal Nazarewicz <mina86@mina86.com>
Signed-off-by: NDaniel Wagner <daniel.wagner@bmw-carit.de>
Cc: Felipe Balbi <balbi@kernel.org>
Cc: Michal Nazarewicz <mina86@mina86.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: linux-usb@vger.kernel.org
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

ffs_func_eps_disable is called from atomic context so it cannot sleep
thus cannot grab a mutex.  Change the handling of epfile->read_buffer
to use non-sleeping synchronisation method.
Reported-by: NChen Yu <chenyu56@huawei.com>
Signed-off-by: NMichał Nazarewicz <mina86@mina86.com>
Fixes: 9353afbb ("buffer data from ‘oversized’ OUT requests")
Tested-by: NJohn Stultz <john.stultz@linaro.org>
Tested-by: NChen Yu <chenyu56@huawei.com>
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

epfile->ep is protected by ffs->eps_lock (not epfile->mutex) so clear it
while holding the spin lock.
Tested-by: NJohn Stultz <john.stultz@linaro.org>
Tested-by: NChen Yu <chenyu56@huawei.com>
Signed-off-by: NMichal Nazarewicz <mina86@mina86.com>
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

CURRENT_TIME macro is not appropriate for filesystems as it
doesn't use the right granularity for filesystem timestamps.
Use current_time() instead.

CURRENT_TIME is also not y2038 safe.

This is also in preparation for the patch that transitions
vfs timestamps to use 64 bit time and hence make them
y2038 safe. As part of the effort current_time() will be
extended to do range checks. Hence, it is necessary for all
file system timestamps to use current_time(). Also,
current_time() will be transitioned along with vfs to be
y2038 safe.

Note that whenever a single call to current_time() is used
to change timestamps in different inodes, it is because they
share the same time granularity.
Signed-off-by: NDeepa Dinamani <deepa.kernel@gmail.com>
Reviewed-by: NArnd Bergmann <arnd@arndb.de>
Acked-by: NFelipe Balbi <balbi@kernel.org>
Acked-by: NSteven Whitehouse <swhiteho@redhat.com>
Acked-by: NRyusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Acked-by: NDavid Sterba <dsterba@suse.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

The struct ffs_data::private_data has a pointer to
ffs_dev stored in it during the ffs_fs_mount() function
however it is not cleared when the ffs_dev is freed
later which causes the ffs_closed function to crash
with "Unable to handle kernel NULL pointer dereference"
error when using the data in ffs_data::private_data.

This clears this pointer during the ffs_free_dev clean
up function.
Signed-off-by: NJim Baxter <jim_baxter@mentor.com>
Signed-off-by: NJiada Wang <jiada_wang@mentor.com>
Signed-off-by: NHarish Jenny K N <harish_kandiga@mentor.com>
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

Introduces a new FunctionFS descriptor flag named
FUNCTIONFS_CONFIG0_SETUP.

When this flag is enabled, FunctionFS userspace drivers can process
non-standard control requests in configuration 0.
Signed-off-by: NFelix Hädicke <felixhaedicke@web.de>
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

It can sometimes be necessary for gadget drivers to process non-standard
control requests, which host devices can send without having sent
USB_REQ_SET_CONFIGURATION.

Therefore, the req_match() usb_function method is enhanced with the new
parameter "config0". When a USB configuration is active, this parameter
is false. When a non-core control request is processed in
composite_setup(), without an active configuration, req_match() of the
USB functions of all available configurations which implement this
function, is called with config0=true. Then the control request gets
processed by the first usb_function instance whose req_match() returns
true.
Signed-off-by: NFelix Hädicke <felixhaedicke@web.de>
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

Introduces a new FunctionFS descriptor flag named
FUNCTIONFS_ALL_CTRL_RECIP. When this flag is enabled, control requests,
which are not explicitly directed to an interface or endpoint, can be
handled.

This allows FunctionFS userspace drivers to process non-standard
control requests.
Signed-off-by: NFelix Hädicke <felixhaedicke@web.de>
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

Return -ENOMEM if kmalloc() fails.

Fixes: 9353afbb ('usb: gadget: f_fs: buffer data from ‘oversized’ OUT requests')
Signed-off-by: NDan Carpenter <dan.carpenter@oracle.com>
Acked-by: NMichal Nazarewicz <mina86@mina86.com>
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

f_fs rounds up read(2) requests to a multiple of a max packet size
which means that host may provide more data than user has space for.
So far, the excess data has been silently ignored.

This introduces a buffer for a tail of such requests so that they are
returned on next read instead of being ignored.
Signed-off-by: NMichal Nazarewicz <mina86@mina86.com>
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

Add a pr_err when host sent more data then the size of the buffer user
space gave us.  This may happen on UDCs which require OUT requests to
be aligned to max packet size.  The patch includes a description of the
situation.
Signed-off-by: NMichal Nazarewicz <mina86@mina86.com>
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

Those are enabled with W=1 make option.

The patch leaves of some type-limits warnings which are caused by
generic macros used in a way where they produce always-false
conditions.
Signed-off-by: NMichal Nazarewicz <mina86@mina86.com>
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>

If c->cdev->use_os_string flag is not set,
don't need to invoke ffs_do_os_descs() in _ffs_func_bind.
So uninitialized ext_compat_id pointer won't be accessed by
__ffs_func_bind_do_os_desc to cause kernel panic.
Signed-off-by: NJim Lin <jilin@nvidia.com>
Signed-off-by: NFelipe Balbi <felipe.balbi@linux.intel.com>