usb: gadget: f_midi: Replace strlcpy() with strscpy()

strlcpy() reads the entire source buffer first. This read may exceed
the destination size limit. This is both inefficient and can lead
to linear read overflows if a source string is not NUL-terminated[1].
Additionally, it returns the size of the source string, not the
resulting size of the destination string. In an effort to remove strlcpy()
completely[2], replace strlcpy() here with strscpy().

In the unlikely (impossible?) case where opts->id was larger than
PAGE_SIZE, this will now correctly report truncation errors.

Link: https://www.kernel.org/doc/html/latest/process/deprecated.html#strlcpy [1]
Link: https://github.com/KSPP/linux/issues/89 [2]
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Will McVicker <willmcvicker@google.com>
Cc: "Gustavo A. R. Silva" <gustavoars@kernel.org>
Cc: Peter Chen <peter.chen@nxp.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Zhang Qilong <zhangqilong3@huawei.com>
Cc: Linyu Yuan <quic_linyyuan@quicinc.com>
Cc: John Keeping <john@keeping.me.uk>
Cc: Azeem Shaikh <azeemshaikh38@gmail.com>
Cc: linux-usb@vger.kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20231116191452.work.902-kees@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: gadget: f_midi: Annotate struct f_midi with __counted_by

Prepare for the coming implementation by GCC and Clang of the __counted_by
attribute. Flexible array members annotated with __counted_by can have
their accesses bounds-checked at run-time checking via CONFIG_UBSAN_BOUNDS
(for array indexing) and CONFIG_FORTIFY_SOURCE (for strcpy/memcpy-family
functions).

As found with Coccinelle[1], add __counted_by for struct f_midi.
Additionally, since the element count member must be set before accessing
the annotated flexible array member, move its initialization earlier.

[1] https://github.com/kees/kernel-tools/blob/trunk/coccinelle/examples/counted_by.cocci

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: John Keeping <john@keeping.me.uk>
Cc: Peter Chen <peter.chen@nxp.com>
Cc: Hulk Robot <hulkci@huawei.com>
Cc: Allen Pais <allen.lkml@gmail.com>
Cc: Will McVicker <willmcvicker@google.com>
Cc: Davidlohr Bueso <dave@stgolabs.net>
Cc: Zhang Qilong <zhangqilong3@huawei.com>
Cc: linux-usb@vger.kernel.org
Reviewed-by: "Gustavo A. R. Silva" <gustavoars@kernel.org>
Link: https://lore.kernel.org/r/20230915195938.never.611-kees@kernel.org
Signed-off-by: Kees Cook <keescook@chromium.org>

usb: gadget: unconditionally allocate hs/ss descriptor in bind operation

Take f_midi_bind() for example, when composite layer call it, it will
allocate hs descriptor by calling gadget_is_dualspeed() API to check
gadget max support speed capability, but most other gadget function didn't
do like this.

To follow other function drivers, it is safe to remove the check which
mean support all possible link speed by default in function driver.

Similar change apply to midi2 and uvc.

Also in midi and midi2, as there is no descriptor difference between
super speed and super speed plus, follow other gadget function drivers,
do not allocate descriptor for super speed plus, composite layer will
handle it properly.

Signed-off-by: Linyu Yuan <quic_linyyuan@quicinc.com>
Link: https://lore.kernel.org/r/20230803091053.9714-5-quic_linyyuan@quicinc.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: gadget: f_midi: allow resetting index option

Unlike the other integral options supported by the MIDI gadget, index is
a signed integer and defaults to -1, which means "choose any sound card
index". The generic store routine parses input into a u32 which fails
to properly read -1 if an attempt is made to set the value to the
default.

Add a new macro block for signed values to fix this, and use the correct
format string for unsigned values.

Signed-off-by: John Keeping <john@metanate.com>
Link: https://lore.kernel.org/r/20211029134115.351008-1-john@metanate.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb/gadget: f_midi: Replace tasklet with work

Currently a tasklet is used to transmit input substream buffer
data. However, tasklets have long been deprecated as being too
heavy on the system by running in irq context - and this is not
a performance critical path. If a higher priority process wants
to run, it must wait for the tasklet to finish before doing so.

Deferring work to a workqueue and executing in process context
should be fine considering the callback already does
f_midi_do_transmit() under the transmit_lock and thus changes in
semantics are ok regarding concurrency - tasklets being serialized
against itself.

Cc: Takashi Iwai <tiwai@suse.de>
Reviewed-by: Takashi Iwai <tiwai@suse.de>
Acked-by: Felipe Balbi <balbi@kernel.org>
Signed-off-by: Davidlohr Bueso <dbueso@suse.de>
Link: https://lore.kernel.org/r/20210111042855.73289-1-dave@stgolabs.net
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

USB: gadget: f_midi: setup SuperSpeed Plus descriptors

Needed for SuperSpeed Plus support for f_midi. This allows the
gadget to work properly without crashing at SuperSpeed rates.

Cc: Felipe Balbi <balbi@kernel.org>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Will McVicker <willmcvicker@google.com>
Reviewed-by: Peter Chen <peter.chen@nxp.com>
Link: https://lore.kernel.org/r/20201127140559.381351-4-gregkh@linuxfoundation.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: gadget: f_midi: Fix memleak in f_midi_alloc

In the error path, if midi is not null, we should
free the midi->id if necessary to prevent memleak.

Fixes: b85e9de9e818d ("usb: gadget: f_midi: convert to new function interface with backward compatibility")
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Zhang Qilong <zhangqilong3@huawei.com>
Link: https://lore.kernel.org/r/20201117021629.1470544-2-zhangqilong3@huawei.com
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb/gadget: f_midi: convert tasklets to use new tasklet_setup() API

In preparation for unconditionally passing the
struct tasklet_struct pointer to all tasklet
callbacks, switch to using the new tasklet_setup()
and from_tasklet() to pass the tasklet pointer explicitly.

Signed-off-by: Romain Perier <romain.perier@gmail.com>
Signed-off-by: Allen Pais <allen.lkml@gmail.com>
Link: https://lore.kernel.org/r/20200817090209.26351-5-allen.cryptic@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

treewide: Use struct_size() for kmalloc()-family

One of the more common cases of allocation size calculations is finding
the size of a structure that has a zero-sized array at the end, along
with memory for some number of elements for that array. For example:

struct foo {
int stuff;
void *entry[];
};

instance = kmalloc(sizeof(struct foo) + sizeof(void *) * count, GFP_KERNEL);

Instead of leaving these open-coded and prone to type mistakes, we can
now use the new struct_size() helper:

instance = kmalloc(struct_size(instance, entry, count), GFP_KERNEL);

This patch makes the changes for kmalloc()-family (and kvmalloc()-family)
uses. It was done via automatic conversion with manual review for the
"CHECKME" non-standard cases noted below, using the following Coccinelle
script:

// pkey_cache = kmalloc(sizeof *pkey_cache + tprops->pkey_tbl_len *
// sizeof *pkey_cache->table, GFP_KERNEL);
@@
identifier alloc =~ "kmalloc|kzalloc|kvmalloc|kvzalloc";
expression GFP;
identifier VAR, ELEMENT;
expression COUNT;
@@

- alloc(sizeof(*VAR) + COUNT * sizeof(*VAR->ELEMENT), GFP)
+ alloc(struct_size(VAR, ELEMENT, COUNT), GFP)

// mr = kzalloc(sizeof(*mr) + m * sizeof(mr->map[0]), GFP_KERNEL);
@@
identifier alloc =~ "kmalloc|kzalloc|kvmalloc|kvzalloc";
expression GFP;
identifier VAR, ELEMENT;
expression COUNT;
@@

- alloc(sizeof(*VAR) + COUNT * sizeof(VAR->ELEMENT[0]), GFP)
+ alloc(struct_size(VAR, ELEMENT, COUNT), GFP)

// Same pattern, but can't trivially locate the trailing element name,
// or variable name.
@@
identifier alloc =~ "kmalloc|kzalloc|kvmalloc|kvzalloc";
expression GFP;
expression SOMETHING, COUNT, ELEMENT;
@@

- alloc(sizeof(SOMETHING) + COUNT * sizeof(ELEMENT), GFP)
+ alloc(CHECKME_struct_size(&SOMETHING, ELEMENT, COUNT), GFP)

Signed-off-by: Kees Cook <keescook@chromium.org>

usb: gadget: f_midi: Use refcount when freeing f_midi_opts

Currently, the midi function is not freed until it is
both removed from the config and released by the user.
Since the user could take a long time to release the
card, it's possible that the function could be unlinked
and thus f_midi_opts would be null when freeing f_midi.

Thus, refcount f_midi_opts and only free it when it is
unlinked and all f_midis have been freed.

Signed-off-by: Jerry Zhang <zhangjerry@google.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

USB: gadget: f_midi: fixing a possible double-free in f_midi

It looks like there is a possibility of a double-free vulnerability on an
error path of the f_midi_set_alt function in the f_midi driver. If the
path is feasible then free_ep_req gets called twice:

req->complete = f_midi_complete;
err = usb_ep_queue(midi->out_ep, req, GFP_ATOMIC);
=> ...
usb_gadget_giveback_request
=>
f_midi_complete (CALLBACK)
(inside f_midi_complete, for various cases of status)
free_ep_req(ep, req); // first kfree
if (err) {
ERROR(midi, "%s: couldn't enqueue request: %d\n",
midi->out_ep->name, err);
free_ep_req(midi->out_ep, req); // second kfree
return err;
}

The double-free possibility was introduced with commit ad0d1a058eac
("usb: gadget: f_midi: fix leak on failed to enqueue out requests").

Found by MOXCAFE tool.

Signed-off-by: Tuba Yavuz <tuba@ece.ufl.edu>
Fixes: ad0d1a058eac ("usb: gadget: f_midi: fix leak on failed to enqueue out requests")
Acked-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

USB: gadget: function: Remove redundant license text

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: Felipe Balbi <felipe.balbi@linux.intel.com>
Acked-by: Michal Nazarewicz <mina86@mina86.com>
Acked-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Vincent Pelletier <plr.vincent@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

USB: add SPDX identifiers to all remaining files in drivers/usb/

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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Acked-by: Johan Hovold <johan@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: gadget: make config_item_type structures const

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: Bhumika Goyal <bhumirks@gmail.com>
Acked-by: Felipe Balbi <felipe.balbi@linux.intel.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

usb: gadget: f_midi: Use snd_card_free_when_closed with refcount

Currenly, f_midi_free uses snd_card_free, which will wait
until the user has released the sound card before
returning. However, if the user doesn't release the sound
card, then f_midi_free can block for an arbitrary amount
of time, which also blocks any gadget operations on that
thread.

Instead, we can use snd_card_free_when_closed which returns
before all handles are released. Since f_midi can be
accessed through rmidi if usb_put_function is called before
release_card_device, add refcounting to f_midi_free and
have rawmidi's private free call it. The f_midi memory
is only kfreed when usb_put_function and release_card_device
have both been called.

Signed-off-by: Jerry Zhang <zhangjerry@google.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

usb: gadget: f_midi: add super speed support

Add super speed descriptors for f_midi.

Signed-off-by: Badhri Jagan Sridharan <Badhri@google.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

usb: gadget: f_midi: constify snd_rawmidi_ops structures

These snd_rawmidi_ops structures are only passed as the third
argument of snd_rawmidi_set_ops. This argument is const, so the
snd_rawmidi_ops structures can be const too.

Done with the help of Coccinelle.

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

usb: gadget: remove useless parameter in alloc_ep_req()

The default_length parameter of alloc_ep_req was not really necessary
and gadget drivers would almost always create an inline function to pass
the same value to len and default_len.

This patch removes that parameter and updates all calls to alloc_ep_req() to
use the new API.

Signed-off-by: Felipe F. Tonello <eu@felipetonello.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

usb: gadget: f_midi: drop substreams when disabling endpoint

This change makes sure that the ALSA buffers are cleaned if an endpoint
becomes disabled.

Before this change, if the internal ALSA buffer did overflow, the MIDI
function would stop sending MIDI to the host.

Signed-off-by: Felipe F. Tonello <eu@felipetonello.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

usb: gadget: f_midi: refactor state machine

This refactor results in a cleaner state machine code and promotes
consistency, readability, and maintanability of this driver.

This refactor state machine was well tested and it is currently running in
production code and devices.

Signed-off-by: Felipe F. Tonello <eu@felipetonello.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

usb: gadget: f_midi: defaults buflen sizes to 512

512 is the value used by wMaxPacketSize, as specified by the USB Spec. This
makes sure this driver uses, by default, the most optimal value for IN and OUT
endpoint requests.

Signed-off-by: Felipe F. Tonello <eu@felipetonello.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

usb: gadget: f_midi: remove alignment code for OUT endpoint

The new version of alloc_ep_req() already aligns the buffer size to
wMaxPacketSize on OUT endpoints.

Signed-off-by: Felipe F. Tonello <eu@felipetonello.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

usb: gadget: f_midi: unlock on error

We added some new locking here, but missed an error path where we need
to unlock.

Fixes: 9acdf4df2fc4 ('usb: gadget: f_midi: added spinlock on transmit function')
Acked-by: Michal Nazarewicz <mina86@mina86.com>
Acked-by: Felipe F. Tonello <eu@felipetonello.com>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

usb: gadget: f_midi: Fixed a bug when buflen was smaller than wMaxPacketSize

buflen by default (256) is smaller than wMaxPacketSize (512) in high-speed
devices.

That caused the OUT endpoint to freeze if the host send any data packet of
length greater than 256 bytes.

This is an example dump of what happended on that enpoint:
HOST: [DATA][Length=260][...]
DEVICE: [NAK]
HOST: [PING]
DEVICE: [NAK]
HOST: [PING]
DEVICE: [NAK]
...
HOST: [PING]
DEVICE: [NAK]

This patch fixes this problem by setting the minimum usb_request's buffer size
for the OUT endpoint as its wMaxPacketSize.

Acked-by: Michal Nazarewicz <mina86@mina86.com>
Signed-off-by: Felipe F. Tonello <eu@felipetonello.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

usb: gadget: f_midi: added spinlock on transmit function

Since f_midi_transmit is called by both ALSA and USB sub-systems, it can
potentially cause a race condition between both calls because f_midi_transmit
is not reentrant nor thread-safe. This is due to an implementation detail that
the transmit function looks for the next available usb request from the fifo
and only enqueues it if there is data to send, otherwise just re-uses it. So,
if both ALSA and USB frameworks calls this function at the same time,
kfifo_seek() will return the same usb_request, which will cause a race
condition.

To solve this problem a syncronization mechanism is necessary. In this case it
is used a spinlock since f_midi_transmit is also called by usb_request->complete
callback in interrupt context.

Cc: <stable@vger.kernel.org> # v4.5+
Fixes: e1e3d7ec5da3 ("usb: gadget: f_midi: pre-allocate IN requests")
Signed-off-by: Felipe F. Tonello <eu@felipetonello.com>
Signed-off-by: Felipe Balbi <balbi@kernel.org>

usb: gadget: f_midi: stash substream in gmidi_in_port structure

For every in_substream, there must be a corresponding gmidi_in_port
structure so it is perfectly viable and some might argue sensible to
stash pointer to the input substream in the gmidi_in_port structure.

This has an added benefit that if in_ports < MAX_PORTS, the whole
f_midi structure takes up less space because only in_ports number of
pointers for in_substream are allocated instead of MAX_PORTS lots of
them.

Signed-off-by: Michal Nazarewicz <mina86@mina86.com>
Signed-off-by: Felipe Balbi <balbi@kernel.org>

usb: gadget: f_midi: missing unlock on error path

We added a new error path to this function and we forgot to drop the
lock.

Fixes: e1e3d7ec5da3 ('usb: gadget: f_midi: pre-allocate IN requests')
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
[mina86@mina86.com: rebased on top of refactoring commit]
Signed-off-by: Michal Nazarewicz <mina86@mina86.com>

Signed-off-by: Felipe Balbi <balbi@kernel.org>

usb: gadget: f_midi: use flexible array member for gmidi_in_port elements

Reduce number of allocations, simplify memory management and reduce
memory usage by stacking the gmidi_in_port elements at the end of the
f_midi structure using a flexible array.

Signed-off-by: Michal Nazarewicz <mina86@mina86.com>
Signed-off-by: Felipe Balbi <balbi@kernel.org>

usb: gadget: f_midi: fix in_last_port looping logic

In general case, all of midi->in_port pointers may be non-NULL which
implies that the ‘if (\!port)’ condition will never execute thus never
zeroing midi->in_last_port. Fix by rewriting the loop such that the
field is set to zero if \!port or end of loop has been reached.

Signed-off-by: Michal Nazarewicz <mina86@mina86.com>
Signed-off-by: Felipe Balbi <balbi@kernel.org>

usb: gadget: f_midi: move some of f_midi_transmit to separate func

Move some of the f_midi_transmit to a separate f_midi_do_transmit
function so the massive indention levels are not so jarring. This
introduces no changes in behaviour.

Signed-off-by: Michal Nazarewicz <mina86@mina86.com>
Signed-off-by: Felipe Balbi <balbi@kernel.org>

usb: gadget: f_midi: remove useless midi reference from port struct

remove a field which is unnecessary. No functional changes.

Signed-off-by: Felipe F. Tonello <eu@felipetonello.com>
Signed-off-by: Michal Nazarewicz <mina86@mina86.com>
Signed-off-by: Felipe Balbi <balbi@kernel.org>

usb: gadget: f_midi: pre-allocate IN requests

This patch introduces pre-allocation of IN endpoint USB requests. This
improves on latency (requires no usb request allocation on transmit) and avoid
several potential probles on allocating too many usb requests (which involves
DMA pool allocation problems).

This implementation also handles better multiple MIDI Gadget ports, always
processing the last processed MIDI substream if the last USB request wasn't
enought to handle the whole stream.

Signed-off-by: Felipe F. Tonello <eu@felipetonello.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

usb: gadget: f_midi: fail if set_alt fails to allocate requests

This ensures that the midi function will only work if the proper number of
IN and OUT requrests are allocated. Otherwise the function will work with less
requests then what the user wants.

Signed-off-by: Felipe F. Tonello <eu@felipetonello.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

usb: gadget: f_midi: set altsettings only for MIDIStreaming interface

This avoids duplication of USB requests for OUT endpoint and
re-enabling endpoints.

Signed-off-by: Felipe F. Tonello <eu@felipetonello.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

usb: gadget: define free_ep_req as universal function

This function is shared between gadget functions, so this avoid unnecessary
duplicated code and potentially avoid memory leaks.

Reviewed-by: Robert Baldyga <r.baldyga@samsung.com>
Signed-off-by: Felipe F. Tonello <eu@felipetonello.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

usb: gadget: f_midi: remove duplicated code

This code is duplicated from f_midi_start_ep(midi, f, midi->out_ep).

Reviewed-by: Robert Baldyga <r.baldyga@samsung.com>
Signed-off-by: Felipe F. Tonello <eu@felipetonello.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

usb: gadget: f_midi: fix leak on failed to enqueue out requests

This patch fixes a memory leak that occurs when an endpoint fails to enqueue
the request. If that happens the complete function will never be called, thus
never freeing the request.

Signed-off-by: Felipe F. Tonello <eu@felipetonello.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

usb: gadget: f_midi: Transmit data only when IN ep is enabled

This makes sure f_midi doesn't try to enqueue data when the IN endpoint is
disabled, ie, USB cable is disconnected.

Reviewed-by: Robert Baldyga <r.baldyga@samsung.com>
Signed-off-by: Felipe F. Tonello <eu@felipetonello.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

usb-gadget/f_midi: use per-attribute show and store methods

To simplify the configfs interface and remove boilerplate code that also
causes binary bloat.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Andrzej Pietrasiewicz <andrzej.p@samsung.com>
Acked-by: Felipe Balbi <balbi@ti.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>

usb: gadget: f_midi: eliminate abuse of ep->driver data

Since ep->driver_data is not used for endpoint claiming, neither for
enabled/disabled state storing, we can reduce number of places where
we read or modify it's value, as now it has no particular meaning for
function or framework logic.

In case of f_midi we only need to store in ep->driver_data pointer to
struct f_midi, as it's used in f_midi_complete() callback and related
functions. All other uses of ep->driver_data are now meaningless and
can be safely removed.

Signed-off-by: Robert Baldyga <r.baldyga@samsung.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

usb: gadget: f_midi: check for error on usb_ep_queue

f_midi is not checking whether there is an error on usb_ep_queue
request, ignoring potential problems, such as memory leaks.

Signed-off-by: Felipe F. Tonello <eu@felipetonello.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

usb: gadget: midi: avoid redundant f_midi_set_alt() call

Function midi registers two interfaces with single set_alt() function
which means that f_midi_set_alt() is called twice when configuration
is set. That means that endpoint initialization and ep request allocation
is done two times. To avoid this problem we do such things only once,
for interface number 1 (MIDI Streaming interface).

Signed-off-by: Robert Baldyga <r.baldyga@samsung.com>
Acked-by: Michal Nazarewicz <mina86@mina86.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

usb: gadget: f_midi: fix error recovery path

In case kstrdup() fails the resources to release are
midi->in_port[] and midi. No cards have been registered,
so no need to unregister any.

Signed-off-by: Andrzej Pietrasiewicz <andrzej.p@samsung.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

usb: gadget: f_midi: fix segfault when reading empty id

When midi function is created, 'id' attribute is initialized with
SNDRV_DEFAULT_STR1, which is NULL pointer. Trying to read this attribute
before filling it ends up with segmentation fault.

This commit fix this issue by preventing null pointer dereference. Now
f_midi_opts_id_show() returns empty string when id is a null pointer.

Reproduction path:

$ mkdir functions/midi.0
$ cat functions/midi.0/id

[ 53.130132] Unable to handle kernel NULL pointer dereference at
virtual address 00000000
[ 53.132630] pgd = ec6cc000
[ 53.135308] [00000000] *pgd=6b759831, *pte=00000000, *ppte=00000000
[ 53.141530] Internal error: Oops: 17 [#1] PREEMPT SMP ARM
[ 53.146904] Modules linked in: usb_f_midi snd_rawmidi libcomposite
[ 53.153071] CPU: 1 PID: 2936 Comm: cat Not tainted
3.19.0-00041-gcf4b216 #7
[ 53.160010] Hardware name: SAMSUNG EXYNOS (Flattened Device Tree)
[ 53.166088] task: ee234c80 ti: ec764000 task.ti: ec764000
[ 53.171482] PC is at strlcpy+0x8/0x60
[ 53.175128] LR is at f_midi_opts_id_show+0x28/0x3c [usb_f_midi]
[ 53.181019] pc : [<c0222a9c>] lr : [<bf01bed0>] psr: 60000053
[ 53.181019] sp : ec765ef8 ip : 00000141 fp : 00000000
[ 53.192474] r10: 00019000 r9 : ed7546c0 r8 : 00010000
[ 53.197682] r7 : ec765f80 r6 : eb46a000 r5 : eb46a000 r4 :
ed754734
[ 53.204192] r3 : ee234c80 r2 : 00001000 r1 : 00000000 r0 :
eb46a000
[ 53.210704] Flags: nZCv IRQs on FIQs off Mode SVC_32 ISA ARM
Segment user
[ 53.217907] Control: 10c5387d Table: 6c6cc04a DAC: 00000015
[ 53.223636] Process cat (pid: 2936, stack limit = 0xec764238)
[ 53.229364] Stack: (0xec765ef8 to 0xec766000)
[ 53.233706] 5ee0:
ed754734 ed7546c0
[ 53.241866] 5f00: eb46a000 bf01bed0 eb753b80 bf01cc44 eb753b98
bf01b0a4 bf01b08c c0125dd0
[ 53.250025] 5f20: 00002f19 00000000 ec432e00 bf01cce8 c0530c00
00019000 00010000 ec765f80
[ 53.258184] 5f40: 00010000 ec764000 00019000 c00cc4ac ec432e00
c00cc55c 00000017 000081a4
[ 53.266343] 5f60: 00000001 00000000 00000000 ec432e00 ec432e00
00010000 00019000 c00cc620
[ 53.274502] 5f80: 00000000 00000000 00000000 00010000 ffff1000
00019000 00000003 c000e9a8
[ 53.282662] 5fa0: 00000000 c000e7e0 00010000 ffff1000 00000003
00019000 00010000 00019000
[ 53.290821] 5fc0: 00010000 ffff1000 00019000 00000003 7fffe000
00000001 00000000 00000000
[ 53.298980] 5fe0: 00000000 be8c68d4 0000b995 b6f0e3e6 40000070
00000003 00000000 00000000
[ 53.307157] [<c0222a9c>] (strlcpy) from [<bf01bed0>]
(f_midi_opts_id_show+0x28/0x3c [usb_f_midi])
[ 53.316006] [<bf01bed0>] (f_midi_opts_id_show [usb_f_midi]) from
[<bf01b0a4>] (f_midi_opts_attr_show+0x18/0x24 )
[ 53.327209] [<bf01b0a4>] (f_midi_opts_attr_show [usb_f_midi]) from
[<c0125dd0>] (configfs_read_file+0x9c/0xec)
[ 53.337180] [<c0125dd0>] (configfs_read_file) from [<c00cc4ac>]
(__vfs_read+0x18/0x4c)
[ 53.345073] [<c00cc4ac>] (__vfs_read) from [<c00cc55c>]
(vfs_read+0x7c/0x100)
[ 53.352190] [<c00cc55c>] (vfs_read) from [<c00cc620>]
(SyS_read+0x40/0x8c)
[ 53.359056] [<c00cc620>] (SyS_read) from [<c000e7e0>]
(ret_fast_syscall+0x0/0x34)
[ 53.366513] Code: ebffe3d3 e8bd8008 e92d4070 e1a05000 (e5d14000)
[ 53.372641] ---[ end trace e4f53a4e233d98d0 ]---

Signed-off-by: Pawel Szewczyk <p.szewczyk@samsung.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

usb: gadget: fix misspelling of current function in string

Replace a misspelled function name by %s and then __func__.

This was done using Coccinelle, including the use of Levenshtein distance,
as proposed by Rasmus Villemoes.

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Signed-off-by: Felipe Balbi <balbi@ti.com>

usb: gadget: midi: f_midi_alloc() can be static

drivers/usb/gadget/function/f_midi.c:1072:21: sparse: symbol 'f_midi_alloc' was not declared. Should it be static?
drivers/usb/gadget/legacy/gmidi.c:118:30: sparse: symbol 'fi_midi' was not declared. Should it be static?
drivers/usb/gadget/legacy/gmidi.c:119:21: sparse: symbol 'f_midi' was not declared. Should it be static?

Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

usb: gadget: f_midi: add configfs support

Make the midi function available for gadgets composed with configfs.

Signed-off-by: Andrzej Pietrasiewicz <andrzej.p@samsung.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

usb: gadget: f_midi: use usb_gstrings_attach

In order to add configfs support the usb_gstrings_attach must be used.

Signed-off-by: Andrzej Pietrasiewicz <andrzej.p@samsung.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

usb: gadget: f_midi: remove compatibility layer

There are no old f_midi interface users left, so remove it.

Signed-off-by: Andrzej Pietrasiewicz <andrzej.p@samsung.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

usb: gadget: f_midi: convert to new function interface with backward compatibility

Converting midi to the new function interface requires converting
the USB midi's function code and its users.

This patch converts the f_midi.c to the new function interface.
The file can now be compiled into a separate usb_f_midi.ko module.

The old function interface is provided by means of a preprocessor
conditional directives. After all users are converted, the old interface
can be removed.

Signed-off-by: Andrzej Pietrasiewicz <andrzej.p@samsung.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

usb: gadget: f_midi: check kstrdup() return value

kstrdup() might fail, so check its return value and react appropriately.

Signed-off-by: Andrzej Pietrasiewicz <andrzej.p@samsung.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

usb: gadget: f_midi: enable use of the index parameter

The soundcard index to use for the ALSA device creation is passed as a
parameter to f_midi_bind_config(), but is assigned to midi->index only
after the call to f_midi_register_card(midi). So no matter what is passed
to f_midi_bind_config(), the actual index for snd_card_new() is always 0.
This probably works ok if at the moment of f_midi's bind there are no
other snd_cards, but if there are, it is not possible to bind f_midi.

This patch moves the assignment to a place before the call to
f_midi_register_card(midi).

Signed-off-by: Andrzej Pietrasiewicz <andrzej.p@samsung.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

usb: gadget: Gadget directory cleanup - group usb functions

The drivers/usb/gadget directory contains many files.
Files which are related can be distributed into separate directories.
This patch moves the USB functions implementations into a separate directory.

Signed-off-by: Andrzej Pietrasiewicz <andrzej.p@samsung.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>