usb: gadget: configfs: Replace snprintf() with the safer scnprintf() variant

There is a general misunderstanding amongst engineers that {v}snprintf()
returns the length of the data *actually* encoded into the destination
array. However, as per the C99 standard {v}snprintf() really returns
the length of the data that *would have been* written if there were
enough space for it. This misunderstanding has led to buffer-overruns
in the past. It's generally considered safer to use the {v}scnprintf()
variants in their place (or even sprintf() in simple cases). So let's
do that.

Link: https://lwn.net/Articles/69419/
Link: https://github.com/KSPP/linux/issues/105
Signed-off-by: Lee Jones <lee@kernel.org>
Link: https://lore.kernel.org/r/20231213164246.1021885-2-lee@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: gadget: Remove snprintf() from sysfs call-backs and replace with sysfs_emit()

Since snprintf() has the documented, but still rather strange trait of
returning the length of the data that *would have been* written to the
array if space were available, rather than the arguably more useful
length of data *actually* written, it is usually considered wise to use
something else instead in order to avoid confusion.

In the case of sysfs call-backs, new wrappers exist that do just that.

This patch replaces just one use of snprintf() found in the sysfs
.show() call-back with the new sysfs_emit() helper.

Link: https://lwn.net/Articles/69419/
Link: https://github.com/KSPP/linux/issues/105
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: linux-usb@vger.kernel.org
Signed-off-by: Lee Jones <lee@kernel.org>
Link: https://lore.kernel.org/r/20231130105459.3208986-5-lee@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: gadget: Properly configure the device for remote wakeup

The wakeup bit in the bmAttributes field indicates whether the device
is configured for remote wakeup. But this field should be allowed to
set only if the UDC supports such wakeup mechanism. So configure this
field based on UDC capability. Also inform the UDC whether the device
is configured for remote wakeup by implementing a gadget op.

Reviewed-by: Thinh Nguyen <Thinh.Nguyen@synopsys.com>
Signed-off-by: Elson Roy Serrao <quic_eserrao@quicinc.com>
Link: https://lore.kernel.org/r/1679694482-16430-2-git-send-email-quic_eserrao@quicinc.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: gadget: configfs: Fix set but not used variable warning

Fix a -Wunused-but-set-variable warning in gadget_string_s_store()

Fixes: 15a7cf8caabe ("usb: gadget: configfs: Support arbitrary string descriptors")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Daniel Scally <dan.scally@ideasonboard.com>
Link: https://lore.kernel.org/r/20230209094359.1549629-1-dan.scally@ideasonboard.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: gadget: configfs: Attach arbitrary strings to cdev

Attach any arbitrary strings that are defined to the composite dev.
We handle the old-style manufacturer, product and serialnumbers
strings in the same function for simplicity.

Signed-off-by: Daniel Scally <dan.scally@ideasonboard.com>
Link: https://lore.kernel.org/r/20230206161802.892954-8-dan.scally@ideasonboard.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: gadget: configfs: Support arbitrary string descriptors

Add a framework to allow users to define arbitrary string descriptors
for a USB Gadget. This is modelled as a new type of config item rather
than as hardcoded attributes so as to be as flexible as possible.

Signed-off-by: Daniel Scally <dan.scally@ideasonboard.com>
Link: https://lore.kernel.org/r/20230206161802.892954-7-dan.scally@ideasonboard.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: gadget: configfs: Rename struct gadget_strings

The struct gadget_strings really represents a single language in
configfs. Rename it to make that more clear.

Signed-off-by: Daniel Scally <dan.scally@ideasonboard.com>
Link: https://lore.kernel.org/r/20230206161802.892954-6-dan.scally@ideasonboard.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: gadget: configfs: Use memcpy_and_pad()

Instead of zeroing some memory and then copying data in part or all of it,
use memcpy_and_pad().
This avoids writing some memory twice and should save a few cycles.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20230202151736.64552-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: gadget: configfs: Restrict symlink creation is UDC already binded

During enumeration or composition switch,a userspace process
agnostic of the conventions of configs can try to create function
symlinks even after the UDC is bound to current config which is
not correct. Potentially it can create duplicates within the
current config.

Prevent this by adding a check if udc_name already exists, then bail
out of cfg_link.

Following is an example:

Step1:
ln -s X1 ffs.a
-->cfg_link
--> usb_get_function(ffs.a)
->ffs_alloc

CFG->FUNC_LIST: <ffs.a>
C->FUNCTION: <empty>

Step2:
echo udc.name > /config/usb_gadget/g1/UDC
--> UDC_store
->composite_bind
->usb_add_function

CFG->FUNC_LIST: <empty>
C->FUNCTION: <ffs.a>

Step3:
ln -s Y1 ffs.a
-->cfg_link
-->usb_get_function(ffs.a)
->ffs_alloc

CFG->FUNC_LIST: <ffs.a>
C->FUNCTION: <ffs.a>

both the lists corresponds to the same function instance ffs.a
but the usb_function* pointer is different because in step 3
ffs_alloc has created a new reference to usb_function* for
ffs.a and added it to cfg_list.

Step4:
Now a composition switch involving <ffs.b,ffs.a> is executed.

the composition switch will involve 3 things:
1. unlinking the previous functions existing
2. creating new symlinks
3. writing UDC

However, the composition switch is generally taken care by
userspace process which creates the symlinks in its own
nomenclature(X*) and removes only those.
So it won't be able to remove Y1 which user had created
by own.

Due to this the new symlinks cannot be created for ffs.a
since the entry already exists in CFG->FUNC_LIST.

The state of the CFG->FUNC_LIST is as follows:
CFG->FUNC_LIST: <ffs.a>

Fixes: 88af8bbe4ef7 ("usb: gadget: the start of the configfs interface")
Signed-off-by: Krishna Kurapati PSSNV <quic_kriskura@quicinc.com>
Signed-off-by: Udipto Goswami <quic_ugoswami@quicinc.com>
Link: https://lore.kernel.org/r/20230201132308.31523-1-quic_ugoswami@quicinc.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usg: gadget: Move validation out of lock in webusb_bcdVersion_store()

Validation has nothing to do with any protected data,
move it out of the lock and make code neater.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20230127112638.84806-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: gadget: Move kstrtox() out of lock

The kstrtox() calls operate on local (to the function) variables and do
not need to be serialized. We may call them out of the lock.

Reviewed-by: John Keeping <john@metanate.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20230120182434.24245-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: gadget: add WebUSB landing page support

There is a custom (non-USB IF) extension to the USB standard:

https://wicg.github.io/webusb/

This specification is published under the W3C Community Contributor
Agreement, which in particular allows to implement the specification
without any royalties.

The specification allows USB gadgets to announce an URL to landing
page and describes a Javascript interface for websites to interact
with the USB gadget, if the user allows it. It is currently
supported by Chromium-based browsers, such as Chrome, Edge and
Opera on all major operating systems including Linux.

This patch adds optional support for Linux-based USB gadgets
wishing to expose such a landing page.

During device enumeration, a host recognizes that the announced
USB version is at least 2.01, which means, that there are BOS
descriptors available. The device than announces WebUSB support
using a platform device capability. This includes a vendor code
under which the landing page URL can be retrieved using a
vendor-specific request.

Previously, the BOS descriptors would unconditionally include an
LPM related descriptor, as BOS descriptors were only ever sent
when the device was LPM capable. As this is no longer the case,
this patch puts this descriptor behind a lpm_capable condition.

Usage is modeled after os_desc descriptors:
echo 1 > webusb/use
echo "https://www.kernel.org" > webusb/landingPage

lsusb will report the device with the following lines:
Platform Device Capability:
bLength 24
bDescriptorType 16
bDevCapabilityType 5
bReserved 0
PlatformCapabilityUUID {3408b638-09a9-47a0-8bfd-a0768815b665}
WebUSB:
bcdVersion 1.00
bVendorCode 0
iLandingPage 1 https://www.kernel.org

Signed-off-by: Jó Ágila Bitsch <jgilab@gmail.com>
Link: https://lore.kernel.org/r/Y8Crf8P2qAWuuk/F@jo-einhundert
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

USB: gadget: Add ID numbers to configfs-gadget driver names

It is unable to use configfs to attach more than one gadget. When
attaching the second gadget, it always fails and the kernel message
prints out:

Error: Driver 'configfs-gadget' is already registered, aborting...
UDC core: g1: driver registration failed: -16

This commit fixes the problem by using the gadget name as a suffix
to each configfs_gadget's driver name, thus making the names
distinct.

Fixes: fc274c1e9973 ("USB: gadget: Add a new bus for gadgets")
Cc: stable <stable@kernel.org>
Signed-off-by: Chanh Nguyen <chanh@os.amperecomputing.com>
Reviewed-by: Andrzej Pietrasiewicz <andrzej.p@collabora.com>
Tested-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Reviewed-by: Frank Li <frank.li@nxp.com>
Link: https://lore.kernel.org/r/20230111065105.29205-1-chanh@os.amperecomputing.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: gadget: Use kstrtobool() instead of strtobool()

strtobool() is the same as kstrtobool().
However, the latter is more used within the kernel.

In order to remove strtobool() and slightly simplify kstrtox.h, switch to
the other function name.

While at it, include the corresponding header file (<linux/kstrtox.h>)

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Link: https://lore.kernel.org/r/09bc980d8432a4b5f7d88388ec0df5b085583139.1667336095.git.christophe.jaillet@wanadoo.fr
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

USB: gadget: Rename usb_gadget_probe_driver()

In preparation for adding a "gadget" bus, this patch renames
usb_gadget_probe_driver() to usb_gadget_register_driver(). The new
name will be more accurate, since gadget drivers will be registered on
the gadget bus and the probing will be done by the driver core, not
the UDC core.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Link: https://lore.kernel.org/r/YmSc29YZvxgT5fEJ@rowland.harvard.edu
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: gadget: configfs: clear deactivation flag in configfs_composite_unbind()

If any function like UVC is deactivating gadget as part of composition
switch which results in not calling pullup enablement, it is not getting
enabled after switch to new composition due to this deactivation flag
not cleared. This results in USB enumeration not happening after switch
to new USB composition. Hence clear deactivation flag inside gadget
structure in configfs_composite_unbind() before switch to new USB
composition.

Signed-off-by: Vijayavardhan Vennapusa <vvreddy@codeaurora.org>
Signed-off-by: Dan Vacura <w36195@motorola.com>
Cc: stable <stable@kernel.org>
Link: https://lore.kernel.org/r/20220413211038.72797-1-w36195@motorola.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: gadget: configfs: remove using list iterator after loop body as a ptr

If the list does not contain the expected element, the value of
list_for_each_entry() iterator will not point to a valid structure.
To avoid type confusion in such case, the list iterator
scope will be limited to list_for_each_entry() loop.

In preparation to limiting scope of a list iterator to the list traversal
loop, use a dedicated pointer to point to the found element [1].
Determining if an element was found is then simply checking if
the pointer is != NULL instead of using the potentially bogus pointer.

Link: https://lore.kernel.org/all/YhdfEIwI4EdtHdym@kroah.com/
Signed-off-by: Jakob Koschel <jakobkoschel@gmail.com>
Link: https://lore.kernel.org/r/20220308171818.384491-18-jakobkoschel@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: gadget: configfs: use to_usb_function_instance() in cfg (un)link func

replace open-coded container_of() with to_usb_function_instance() helper.

Reviewed-by: Jack Pham <quic_jackp@quicinc.com>
Signed-off-by: Linyu Yuan <quic_linyyuan@quicinc.com>
Link: https://lore.kernel.org/r/1637211213-16400-5-git-send-email-quic_linyyuan@quicinc.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: gadget: configfs: use to_config_usb_cfg() in os_desc_link()

replace open-coded container_of() with to_config_usb_cfg() helper.

Reviewed-by: Jack Pham <quic_jackp@quicinc.com>
Signed-off-by: Linyu Yuan <quic_linyyuan@quicinc.com>
Link: https://lore.kernel.org/r/1637211213-16400-4-git-send-email-quic_linyyuan@quicinc.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: gadget: configfs: remove os_desc_attr_release()

it is not allow to create sub group under os_desc,

/sys/kernel/config/usb_gadget/dummy/os_desc # mkdir dummy
mkdir: can't create directory 'dummy': Operation not permitted

no one will kmalloc() os_desc entry and kfree(os_desc) will never be called.
static void os_desc_attr_release(struct config_item *item)
{
struct os_desc *os_desc = to_os_desc(item);
kfree(os_desc);
}

remove struct os_desc definition, to_os_desc() and os_desc_attr_release().

Reviewed-by: Jack Pham <quic_jackp@quicinc.com>
Signed-off-by: Linyu Yuan <quic_linyyuan@quicinc.com>
Link: https://lore.kernel.org/r/1637211213-16400-3-git-send-email-quic_linyyuan@quicinc.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: gadget: configfs: simplify os_desc_item_to_gadget_info() helper

since os_desc_group is already a member of struct gadget_info,
we can simply just use container_of() to retrieve the latter,
without needing to dereference the cg_item's parent pointer.

use os_desc_item_to_gadget_info() helper in os_desc (un)link function.

Reviewed-by: Jack Pham <quic_jackp@quicinc.com>
Signed-off-by: Linyu Yuan <quic_linyyuan@quicinc.com>
Link: https://lore.kernel.org/r/1637211213-16400-2-git-send-email-quic_linyyuan@quicinc.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: gadget: configfs: change config attributes file operation

in order to add trace event in configfs function with same
struct gadget_info *gi parameter,
add struct config_usb_cfg *cfg variable in below functions,
gadget_config_desc_MaxPower_show(),
gadget_config_desc_MaxPower_store(),
gadget_config_desc_bmAttributes_show(),
gadget_config_desc_bmAttributes_store(),
this allow following patch easy change cfg to gi with helper function
cfg_to_gadget_info().

Signed-off-by: Linyu Yuan <quic_linyyuan@quicinc.com>
Link: https://lore.kernel.org/r/1634649997-28745-3-git-send-email-quic_linyyuan@quicinc.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: gadget: configfs: add cfg_to_gadget_info() helper

add this helper function can simplify code of
config_usb_cfg_link() and config_usb_cfg_unlink().

Signed-off-by: Linyu Yuan <quic_linyyuan@quicinc.com>
Link: https://lore.kernel.org/r/1634649997-28745-2-git-send-email-quic_linyyuan@quicinc.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: gadget: Fix inconsistent indent

Remove whitespace and use tab as indent

Acked-by: Felipe Balbi <balbi@kernel.org>
Signed-off-by: Wei Ming Chen <jj251510319013@gmail.com>
Link: https://lore.kernel.org/r/20210801055454.53015-1-jj251510319013@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: gadget: configfs: Check USB configuration before adding

Ensure that the USB gadget is able to support the configuration being
added based on the number of endpoints required from all interfaces. This
is for accounting for any bandwidth or space limitations.

Signed-off-by: Wesley Cheng <wcheng@codeaurora.org>
Link: https://lore.kernel.org/r/1625908395-5498-3-git-send-email-wcheng@codeaurora.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: gadget: configfs: Fix KASAN use-after-free

When gadget is disconnected, running sequence is like this.
. composite_disconnect
. Call trace:
usb_string_copy+0xd0/0x128
gadget_config_name_configuration_store+0x4
gadget_config_name_attr_store+0x40/0x50
configfs_write_file+0x198/0x1f4
vfs_write+0x100/0x220
SyS_write+0x58/0xa8
. configfs_composite_unbind
. configfs_composite_bind

In configfs_composite_bind, it has
"cn->strings.s = cn->configuration;"

When usb_string_copy is invoked. it would
allocate memory, copy input string, release previous pointed memory space,
and use new allocated memory.

When gadget is connected, host sends down request to get information.
Call trace:
usb_gadget_get_string+0xec/0x168
lookup_string+0x64/0x98
composite_setup+0xa34/0x1ee8

If gadget is disconnected and connected quickly, in the failed case,
cn->configuration memory has been released by usb_string_copy kfree but
configfs_composite_bind hasn't been run in time to assign new allocated
"cn->configuration" pointer to "cn->strings.s".

When "strlen(s->s) of usb_gadget_get_string is being executed, the dangling
memory is accessed, "BUG: KASAN: use-after-free" error occurs.

Cc: stable@vger.kernel.org
Signed-off-by: Jim Lin <jilin@nvidia.com>
Signed-off-by: Macpaul Lin <macpaul.lin@mediatek.com>
Link: https://lore.kernel.org/r/1615444961-13376-1-git-send-email-macpaul.lin@mediatek.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: gadget: configfs: Add a specific configFS reset callback

In order for configFS based USB gadgets to set the proper charge current
for bus reset scenarios, expose a separate reset callback to set the
current to 100mA based on the USB battery charging specification.

Reviewed-by: Peter Chen <peter.chen@nxp.com>
Signed-off-by: Wesley Cheng <wcheng@codeaurora.org>
Link: https://lore.kernel.org/r/1609283011-21997-4-git-send-email-wcheng@codeaurora.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: gadget: enable super speed plus

Enable Super speed plus in configfs to support USB3.1 Gen2.
This ensures that when a USB gadget is plugged in, it is
enumerated as Gen 2 and connected at 10 Gbps if the host and
cable are capable of it.

Many in-tree gadget functions (fs, midi, acm, ncm, mass_storage,
etc.) already have SuperSpeed Plus support.

Tested: plugged gadget into Linux host and saw:
[284907.385986] usb 8-2: new SuperSpeedPlus Gen 2 USB device number 3 using xhci_hcd

Tested-by: Lorenzo Colitti <lorenzo@google.com>
Acked-by: Felipe Balbi <balbi@kernel.org>
Signed-off-by: taehyun.cho <taehyun.cho@samsung.com>
Signed-off-by: Lorenzo Colitti <lorenzo@google.com>
Link: https://lore.kernel.org/r/20210106154625.2801030-1-lorenzo@google.com
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: gadget: configfs: Preserve function ordering after bind failure

When binding the ConfigFS gadget to a UDC, the functions in each
configuration are added in list order. However, if usb_add_function()
fails, the failed function is put back on its configuration's
func_list and purge_configs_funcs() is called to further clean up.

purge_configs_funcs() iterates over the configurations and functions
in forward order, calling unbind() on each of the previously added
functions. But after doing so, each function gets moved to the
tail of the configuration's func_list. This results in reshuffling
the original order of the functions within a configuration such
that the failed function now appears first even though it may have
originally appeared in the middle or even end of the list. At this
point if the ConfigFS gadget is attempted to re-bind to the UDC,
the functions will be added in a different order than intended,
with the only recourse being to remove and relink the functions all
over again.

An example of this as follows:

ln -s functions/mass_storage.0 configs/c.1
ln -s functions/ncm.0 configs/c.1
ln -s functions/ffs.adb configs/c.1 # oops, forgot to start adbd
echo "<udc device>" > UDC # fails
start adbd
echo "<udc device>" > UDC # now succeeds, but...
# bind order is
# "ADB", mass_storage, ncm

[30133.118289] configfs-gadget gadget: adding 'Mass Storage Function'/ffffff810af87200 to config 'c'/ffffff817d6a2520
[30133.119875] configfs-gadget gadget: adding 'cdc_network'/ffffff80f48d1a00 to config 'c'/ffffff817d6a2520
[30133.119974] using random self ethernet address
[30133.120002] using random host ethernet address
[30133.139604] usb0: HOST MAC 3e:27:46:ba:3e:26
[30133.140015] usb0: MAC 6e:28:7e:42:66:6a
[30133.140062] configfs-gadget gadget: adding 'Function FS Gadget'/ffffff80f3868438 to config 'c'/ffffff817d6a2520
[30133.140081] configfs-gadget gadget: adding 'Function FS Gadget'/ffffff80f3868438 --> -19
[30133.140098] configfs-gadget gadget: unbind function 'Mass Storage Function'/ffffff810af87200
[30133.140119] configfs-gadget gadget: unbind function 'cdc_network'/ffffff80f48d1a00
[30133.173201] configfs-gadget a600000.dwc3: failed to start g1: -19
[30136.661933] init: starting service 'adbd'...
[30136.700126] read descriptors
[30136.700413] read strings
[30138.574484] configfs-gadget gadget: adding 'Function FS Gadget'/ffffff80f3868438 to config 'c'/ffffff817d6a2520
[30138.575497] configfs-gadget gadget: adding 'Mass Storage Function'/ffffff810af87200 to config 'c'/ffffff817d6a2520
[30138.575554] configfs-gadget gadget: adding 'cdc_network'/ffffff80f48d1a00 to config 'c'/ffffff817d6a2520
[30138.575631] using random self ethernet address
[30138.575660] using random host ethernet address
[30138.595338] usb0: HOST MAC 2e:cf:43:cd:ca:c8
[30138.597160] usb0: MAC 6a:f0:9f:ee:82:a0
[30138.791490] configfs-gadget gadget: super-speed config #1: c

Fix this by reversing the iteration order of the functions in
purge_config_funcs() when unbinding them, and adding them back to
the config's func_list at the head instead of the tail. This
ensures that we unbind and unwind back to the original list order.

Fixes: 88af8bbe4ef7 ("usb: gadget: the start of the configfs interface")
Signed-off-by: Chandana Kishori Chiluveru <cchiluve@codeaurora.org>
Signed-off-by: Jack Pham <jackp@codeaurora.org>
Reviewed-by: Peter Chen <peter.chen@nxp.com>
Link: https://lore.kernel.org/r/20201229224443.31623-1-jackp@codeaurora.org
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: gadget: configfs: Fix use-after-free issue with udc_name

There is a use-after-free issue, if access udc_name
in function gadget_dev_desc_UDC_store after another context
free udc_name in function unregister_gadget.

Context 1:
gadget_dev_desc_UDC_store()->unregister_gadget()->
free udc_name->set udc_name to NULL

Context 2:
gadget_dev_desc_UDC_show()-> access udc_name

Call trace:
dump_backtrace+0x0/0x340
show_stack+0x14/0x1c
dump_stack+0xe4/0x134
print_address_description+0x78/0x478
__kasan_report+0x270/0x2ec
kasan_report+0x10/0x18
__asan_report_load1_noabort+0x18/0x20
string+0xf4/0x138
vsnprintf+0x428/0x14d0
sprintf+0xe4/0x12c
gadget_dev_desc_UDC_show+0x54/0x64
configfs_read_file+0x210/0x3a0
__vfs_read+0xf0/0x49c
vfs_read+0x130/0x2b4
SyS_read+0x114/0x208
el0_svc_naked+0x34/0x38

Add mutex_lock to protect this kind of scenario.

Signed-off-by: Eddie Hung <eddie.hung@mediatek.com>
Signed-off-by: Macpaul Lin <macpaul.lin@mediatek.com>
Reviewed-by: Peter Chen <peter.chen@nxp.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/1609239215-21819-1-git-send-email-macpaul.lin@mediatek.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

USB: replace hardcode maximum usb string length by definition

Replace hardcoded maximum USB string length (126 bytes) by definition
"USB_MAX_STRING_LEN".

Signed-off-by: Macpaul Lin <macpaul.lin@mediatek.com>
Acked-by: Alan Stern <stern@rowland.harvard.edu>
Link: https://lore.kernel.org/r/1592471618-29428-1-git-send-email-macpaul.lin@mediatek.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

USB: gadget: fix illegal array access in binding with UDC

FuzzUSB (a variant of syzkaller) found an illegal array access
using an incorrect index while binding a gadget with UDC.

Reference: https://www.spinics.net/lists/linux-usb/msg194331.html

This bug occurs when a size variable used for a buffer
is misused to access its strcpy-ed buffer.
Given a buffer along with its size variable (taken from user input),
from which, a new buffer is created using kstrdup().
Due to the original buffer containing 0 value in the middle,
the size of the kstrdup-ed buffer becomes smaller than that of the original.
So accessing the kstrdup-ed buffer with the same size variable
triggers memory access violation.

The fix makes sure no zero value in the buffer,
by comparing the strlen() of the orignal buffer with the size variable,
so that the access to the kstrdup-ed buffer is safe.

BUG: KASAN: slab-out-of-bounds in gadget_dev_desc_UDC_store+0x1ba/0x200
drivers/usb/gadget/configfs.c:266
Read of size 1 at addr ffff88806a55dd7e by task syz-executor.0/17208

CPU: 2 PID: 17208 Comm: syz-executor.0 Not tainted 5.6.8 #1
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:77 [inline]
dump_stack+0xce/0x128 lib/dump_stack.c:118
print_address_description.constprop.4+0x21/0x3c0 mm/kasan/report.c:374
__kasan_report+0x131/0x1b0 mm/kasan/report.c:506
kasan_report+0x12/0x20 mm/kasan/common.c:641
__asan_report_load1_noabort+0x14/0x20 mm/kasan/generic_report.c:132
gadget_dev_desc_UDC_store+0x1ba/0x200 drivers/usb/gadget/configfs.c:266
flush_write_buffer fs/configfs/file.c:251 [inline]
configfs_write_file+0x2f1/0x4c0 fs/configfs/file.c:283
__vfs_write+0x85/0x110 fs/read_write.c:494
vfs_write+0x1cd/0x510 fs/read_write.c:558
ksys_write+0x18a/0x220 fs/read_write.c:611
__do_sys_write fs/read_write.c:623 [inline]
__se_sys_write fs/read_write.c:620 [inline]
__x64_sys_write+0x73/0xb0 fs/read_write.c:620
do_syscall_64+0x9e/0x510 arch/x86/entry/common.c:294
entry_SYSCALL_64_after_hwframe+0x49/0xbe

Signed-off-by: Kyungtae Kim <kt0755@gmail.com>
Reported-and-tested-by: Kyungtae Kim <kt0755@gmail.com>
Cc: Felipe Balbi <balbi@kernel.org>
Cc: stable <stable@vger.kernel.org>
Link: https://lore.kernel.org/r/20200510054326.GA19198@pizza01
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: gadget: add "usb_validate_langid" function

The USB LANGID validation code in "check_user_usb_string" function is
moved to "usb_validate_langid" function which can be used by other usb
gadget drivers.

Signed-off-by: Tao Ren <rentao.bupt@gmail.com>
Signed-off-by: Felipe Balbi <balbi@kernel.org>

usb: gadget: configfs: Add max_speed setting

Some functions support speeds other than SuperSpeed. Add max_speed
attribute to configfs gadget allowing user to specify the maximum speed
the composite driver supports. The valid input speed names are
super-speed-plus, super-speed, high-speed, full-speed, and low-speed.

Signed-off-by: Thinh Nguyen <thinhn@synopsys.com>
Signed-off-by: Felipe Balbi <balbi@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: gadget: configfs: Fix missing spin_lock_init()

The driver allocates the spinlock but not initialize it.
Use spin_lock_init() on it to initialize it correctly.

This is detected by Coccinelle semantic patch.

Fixes: 1a1c851bbd70 ("usb: gadget: configfs: fix concurrent issue between composite APIs")
Signed-off-by: Wei Yongjun <weiyongjun1@huawei.com>
Cc: stable <stable@vger.kernel.org>
Reviewed-by: Peter Chen <peter.chen@nxp.com>
Link: https://lore.kernel.org/r/20191030034046.188808-1-weiyongjun1@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: gadget: configfs: fix concurrent issue between composite APIs

We meet several NULL pointer issues if configfs_composite_unbind
and composite_setup (or composite_disconnect) are running together.
These issues occur when do the function switch stress test, the
configfs_compsoite_unbind is called from user mode by
echo "" to /sys/../UDC entry, and meanwhile, the setup interrupt
or disconnect interrupt occurs by hardware. The composite_setup
will get the cdev from get_gadget_data, but configfs_composite_unbind
will set gadget data as NULL, so the NULL pointer issue occurs.
This concurrent is hard to reproduce by native kernel, but can be
reproduced by android kernel.

In this commit, we introduce one spinlock belongs to structure
gadget_info since we can't use the same spinlock in usb_composite_dev
due to exclusive running together between composite_setup and
configfs_composite_unbind. And one bit flag 'unbind' to indicate the
code is at unbind routine, this bit is needed due to we release the
lock at during configfs_composite_unbind sometimes, and composite_setup
may be run at that time.

Several oops:

oops 1:
android_work: sent uevent USB_STATE=CONNECTED
configfs-gadget gadget: super-speed config #1: b
android_work: sent uevent USB_STATE=CONFIGURED
init: Received control message 'start' for 'adbd' from pid: 3515 (system_server)
Unable to handle kernel NULL pointer dereference at virtual address 0000002a
init: Received control message 'stop' for 'adbd' from pid: 3375 (/vendor/bin/hw/android.hardware.usb@1.1-servic)
Mem abort info:
Exception class = DABT (current EL), IL = 32 bits
SET = 0, FnV = 0
EA = 0, S1PTW = 0
Data abort info:
ISV = 0, ISS = 0x00000004
CM = 0, WnR = 0
user pgtable: 4k pages, 48-bit VAs, pgd = ffff8008f1b7f000
[000000000000002a] *pgd=0000000000000000
Internal error: Oops: 96000004 [#1] PREEMPT SMP
Modules linked in:
CPU: 4 PID: 2457 Comm: irq/125-5b11000 Not tainted 4.14.98-07846-g0b40a9b-dirty #16
Hardware name: Freescale i.MX8QM MEK (DT)
task: ffff8008f2a98000 task.stack: ffff00000b7b8000
PC is at composite_setup+0x44/0x1508
LR is at android_setup+0xb8/0x13c
pc : [<ffff0000089ffb3c>] lr : [<ffff000008a032fc>] pstate: 800001c5
sp : ffff00000b7bbb80
x29: ffff00000b7bbb80 x28: ffff8008f2a3c010
x27: 0000000000000001 x26: 0000000000000000 [1232/1897]
audit: audit_lost=25791 audit_rate_limit=5 audit_backlog_limit=64
x25: 00000000ffffffa1 x24: ffff8008f2a3c010
audit: rate limit exceeded
x23: 0000000000000409 x22: ffff000009c8e000
x21: ffff8008f7a8b428 x20: ffff00000afae000
x19: ffff0000089ff000 x18: 0000000000000000
x17: 0000000000000000 x16: ffff0000082b7c9c
x15: 0000000000000000 x14: f1866f5b952aca46
x13: e35502e30d44349c x12: 0000000000000008
x11: 0000000000000008 x10: 0000000000000a30
x9 : ffff00000b7bbd00 x8 : ffff8008f2a98a90
x7 : ffff8008f27a9c90 x6 : 0000000000000001
x5 : 0000000000000000 x4 : 0000000000000001
x3 : 0000000000000000 x2 : 0000000000000006
x1 : ffff0000089ff8d0 x0 : 732a010310b9ed00

X7: 0xffff8008f27a9c10:
9c10 00000002 00000000 00000001 00000000 13110000 ffff0000 00000002 00208040
9c30 00000000 00000000 00000000 00000000 00000000 00000005 00000029 00000000
9c50 00051778 00000001 f27a8e00 ffff8008 00000005 00000000 00000078 00000078
9c70 00000078 00000000 09031d48 ffff0000 00100000 00000000 00400000 00000000
9c90 00000001 00000000 00000000 00000000 00000000 00000000 ffefb1a0 ffff8008
9cb0 f27a9ca8 ffff8008 00000000 00000000 b9d88037 00000173 1618a3eb 00000001
9cd0 870a792a 0000002e 16188fe6 00000001 0000242b 00000000 00000000 00000000
using random self ethernet address
9cf0 019a4646 00000000 000547f3 00000000 ecfd6c33 00000002 00000000
using random host ethernet address
00000000

X8: 0xffff8008f2a98a10:
8a10 00000000 00000000 f7788d00 ffff8008 00000001 00000000 00000000 00000000
8a30 eb218000 ffff8008 f2a98000 ffff8008 f2a98000 ffff8008 09885000 ffff0000
8a50 f34df480 ffff8008 00000000 00000000 f2a98648 ffff8008 09c8e000 ffff0000
8a70 fff2c800 ffff8008 09031d48 ffff0000 0b7bbd00 ffff0000 0b7bbd00 ffff0000
8a90 080861bc ffff0000 00000000 00000000 00000000 00000000 00000000 00000000
8ab0 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
8ad0 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
8af0 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000

X21: 0xffff8008f7a8b3a8:
b3a8 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
b3c8 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
b3e8 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
b408 00000000 00000000 00000000 00000000 00000000 00000000 00000001 00000000
b428 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
b448 0053004d 00540046 00300031 00010030 eb07b520 ffff8008 20011201 00000003
b468 e418d109 0104404e 00010302 00000000 eb07b558 ffff8008 eb07b558 ffff8008
b488 f7a8b488 ffff8008 f7a8b488 ffff8008 f7a8b300 ffff8008 00000000 00000000

X24: 0xffff8008f2a3bf90:
bf90 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
bfb0 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
bfd0 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
bff0 00000000 00000000 00000000 00000000 f76c8010 ffff8008 f76c8010 ffff8008
c010 00000000 00000000 f2a3c018 ffff8008 f2a3c018 ffff8008 08a067dc ffff0000
c030 f2a5a000 ffff8008 091c3650 ffff0000 f716fd18 ffff8008 f716fe30 ffff8008
c050 f2ce4a30 ffff8008 00000000 00000005 00000000 00000000 095d1568 ffff0000
c070 f76c8010 ffff8008 f2ce4b00 ffff8008 095cac68 ffff0000 f2a5a028 ffff8008

X28: 0xffff8008f2a3bf90:
bf90 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
bfb0 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
bfd0 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
bff0 00000000 00000000 00000000 00000000 f76c8010 ffff8008 f76c8010 ffff8008
c010 00000000 00000000 f2a3c018 ffff8008 f2a3c018 ffff8008 08a067dc ffff0000
c030 f2a5a000 ffff8008 091c3650 ffff0000 f716fd18 ffff8008 f716fe30 ffff8008
c050 f2ce4a30 ffff8008 00000000 00000005 00000000 00000000 095d1568 ffff0000
c070 f76c8010 ffff8008 f2ce4b00 ffff8008 095cac68 ffff0000 f2a5a028 ffff8008

Process irq/125-5b11000 (pid: 2457, stack limit = 0xffff00000b7b8000)
Call trace:
Exception stack(0xffff00000b7bba40 to 0xffff00000b7bbb80)
ba40: 732a010310b9ed00 ffff0000089ff8d0 0000000000000006 0000000000000000
ba60: 0000000000000001 0000000000000000 0000000000000001 ffff8008f27a9c90
ba80: ffff8008f2a98a90 ffff00000b7bbd00 0000000000000a30 0000000000000008
baa0: 0000000000000008 e35502e30d44349c f1866f5b952aca46 0000000000000000
bac0: ffff0000082b7c9c 0000000000000000 0000000000000000 ffff0000089ff000
bae0: ffff00000afae000 ffff8008f7a8b428 ffff000009c8e000 0000000000000409
bb00: ffff8008f2a3c010 00000000ffffffa1 0000000000000000 0000000000000001
bb20: ffff8008f2a3c010 ffff00000b7bbb80 ffff000008a032fc ffff00000b7bbb80
bb40: ffff0000089ffb3c 00000000800001c5 ffff00000b7bbb80 732a010310b9ed00
bb60: ffffffffffffffff ffff0000080f777c ffff00000b7bbb80 ffff0000089ffb3c
[<ffff0000089ffb3c>] composite_setup+0x44/0x1508
[<ffff000008a032fc>] android_setup+0xb8/0x13c
[<ffff0000089bd9a8>] cdns3_ep0_delegate_req+0x44/0x70
[<ffff0000089bdff4>] cdns3_check_ep0_interrupt_proceed+0x33c/0x654
[<ffff0000089bca44>] cdns3_device_thread_irq_handler+0x4b0/0x4bc
[<ffff0000089b77b4>] cdns3_thread_irq+0x48/0x68
[<ffff000008145bf0>] irq_thread_fn+0x28/0x88
[<ffff000008145e38>] irq_thread+0x13c/0x228
[<ffff0000080fed70>] kthread+0x104/0x130
[<ffff000008085064>] ret_from_fork+0x10/0x18

oops2:
composite_disconnect: Calling disconnect on a Gadget that is not connected
android_work: did not send uevent (0 0 (null))
init: Received control message 'stop' for 'adbd' from pid: 3359 (/vendor/bin/hw/android.hardware.usb@1.1-service.imx)
init: Sending signal 9 to service 'adbd' (pid 22343) process group...
------------[ cut here ]------------
audit: audit_lost=180038 audit_rate_limit=5 audit_backlog_limit=64
audit: rate limit exceeded
WARNING: CPU: 0 PID: 3468 at kernel_imx/drivers/usb/gadget/composite.c:2009 composite_disconnect+0x80/0x88
Modules linked in:
CPU: 0 PID: 3468 Comm: HWC-UEvent-Thre Not tainted 4.14.98-07846-g0b40a9b-dirty #16
Hardware name: Freescale i.MX8QM MEK (DT)
task: ffff8008f2349c00 task.stack: ffff00000b0a8000
PC is at composite_disconnect+0x80/0x88
LR is at composite_disconnect+0x80/0x88
pc : [<ffff0000089ff9b0>] lr : [<ffff0000089ff9b0>] pstate: 600001c5
sp : ffff000008003dd0
x29: ffff000008003dd0 x28: ffff8008f2349c00
x27: ffff000009885018 x26: ffff000008004000
Timeout for IPC response!
x25: ffff000009885018 x24: ffff000009c8e280
x23: ffff8008f2d98010 x22: 00000000000001c0
x21: ffff8008f2d98394 x20: ffff8008f2d98010
x19: 0000000000000000 x18: 0000e3956f4f075a
fxos8700 4-001e: i2c block read acc failed
x17: 0000e395735727e8 x16: ffff00000829f4d4
x15: ffffffffffffffff x14: 7463656e6e6f6320
x13: 746f6e2009090920 x12: 7369207461687420
x11: 7465676461472061 x10: 206e6f207463656e
x9 : 6e6f637369642067 x8 : ffff000009c8e280
x7 : ffff0000086ca6cc x6 : ffff000009f15e78
x5 : 0000000000000000 x4 : 0000000000000000
x3 : ffffffffffffffff x2 : c3f28b86000c3900
x1 : c3f28b86000c3900 x0 : 000000000000004e

X20: 0xffff8008f2d97f90:
7f90 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
7fb0 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
libprocessgroup: Failed to kill process cgroup uid 0 pid 22343 in 215ms, 1 processes remain
7fd0
Timeout for IPC response!
00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
using random self ethernet address
7ff0 00000000 00000000 00000000 00000000 f76c8010 ffff8008 f76c8010 ffff8008
8010 00000100 00000000 f2d98018 ffff8008 f2d98018 ffff8008 08a067dc
using random host ethernet address
ffff0000
8030 f206d800 ffff8008 091c3650 ffff0000 f7957b18 ffff8008 f7957730 ffff8008
8050 f716a630 ffff8008 00000000 00000005 00000000 00000000 095d1568 ffff0000
8070 f76c8010 ffff8008 f716a800 ffff8008 095cac68 ffff0000 f206d828 ffff8008

X21: 0xffff8008f2d98314:
8314 ffff8008 00000000 00000000 00000000 00000000 00000000 00000000 00000000
8334 00000000 00000000 00000000 00000000 00000000 08a04cf4 ffff0000 00000000
8354 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
8374 00000000 00000000 00000000 00001001 00000000 00000000 00000000 00000000
8394 e4bbe4bb 0f230000 ffff0000 0afae000 ffff0000 ae001000 00000000 f206d400
Timeout for IPC response!
83b4 ffff8008 00000000 00000000 f7957b18 ffff8008 f7957718 ffff8008 f7957018
83d4 ffff8008 f7957118 ffff8008 f7957618 ffff8008 f7957818 ffff8008 f7957918
83f4 ffff8008 f7957d18 ffff8008 00000000 00000000 00000000 00000000 00000000

X23: 0xffff8008f2d97f90:
7f90 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
7fb0 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
7fd0 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
7ff0 00000000 00000000 00000000 00000000 f76c8010 ffff8008 f76c8010 ffff8008
8010 00000100 00000000 f2d98018 ffff8008 f2d98018 ffff8008 08a067dc ffff0000
8030 f206d800 ffff8008 091c3650 ffff0000 f7957b18 ffff8008 f7957730 ffff8008
8050 f716a630 ffff8008 00000000 00000005 00000000 00000000 095d1568 ffff0000
8070 f76c8010 ffff8008 f716a800 ffff8008 095cac68 ffff0000 f206d828 ffff8008

X28: 0xffff8008f2349b80:
9b80 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
9ba0 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
9bc0 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
9be0 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
9c00 00000022 00000000 ffffffff ffffffff 00010001 00000000 00000000 00000000
9c20 0b0a8000 ffff0000 00000002 00404040 00000000 00000000 00000000 00000000
9c40 00000001 00000000 00000001 00000000 001ebd44 00000001 f390b800 ffff8008
9c60 00000000 00000001 00000070 00000070 00000070 00000000 09031d48 ffff0000

Call trace:
Exception stack(0xffff000008003c90 to 0xffff000008003dd0)
3c80: 000000000000004e c3f28b86000c3900
3ca0: c3f28b86000c3900 ffffffffffffffff 0000000000000000 0000000000000000
3cc0: ffff000009f15e78 ffff0000086ca6cc ffff000009c8e280 6e6f637369642067
3ce0: 206e6f207463656e 7465676461472061 7369207461687420 746f6e2009090920
3d00: 7463656e6e6f6320 ffffffffffffffff ffff00000829f4d4 0000e395735727e8
3d20: 0000e3956f4f075a 0000000000000000 ffff8008f2d98010 ffff8008f2d98394
3d40: 00000000000001c0 ffff8008f2d98010 ffff000009c8e280 ffff000009885018
3d60: ffff000008004000 ffff000009885018 ffff8008f2349c00 ffff000008003dd0
3d80: ffff0000089ff9b0 ffff000008003dd0 ffff0000089ff9b0 00000000600001c5
3da0: ffff8008f33f2cd8 0000000000000000 0000ffffffffffff 0000000000000000
init: Received control message 'start' for 'adbd' from pid: 3359 (/vendor/bin/hw/android.hardware.usb@1.1-service.imx)
3dc0: ffff000008003dd0 ffff0000089ff9b0
[<ffff0000089ff9b0>] composite_disconnect+0x80/0x88
[<ffff000008a044d4>] android_disconnect+0x3c/0x68
[<ffff0000089ba9f8>] cdns3_device_irq_handler+0xfc/0x2c8
[<ffff0000089b84c0>] cdns3_irq+0x44/0x94
[<ffff00000814494c>] __handle_irq_event_percpu+0x60/0x24c
[<ffff000008144c0c>] handle_irq_event+0x58/0xc0
[<ffff00000814873c>] handle_fasteoi_irq+0x98/0x180
[<ffff000008143a10>] generic_handle_irq+0x24/0x38
[<ffff000008144170>] __handle_domain_irq+0x60/0xac
[<ffff0000080819c4>] gic_handle_irq+0xd4/0x17c

Signed-off-by: Peter Chen <peter.chen@nxp.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

usb: gadget: configfs: fix concurrent issue between composite APIs

We meet several NULL pointer issues if configfs_composite_unbind
and composite_setup (or composite_disconnect) are running together.
These issues occur when do the function switch stress test, the
configfs_compsoite_unbind is called from user mode by
echo "" to /sys/../UDC entry, and meanwhile, the setup interrupt
or disconnect interrupt occurs by hardware. The composite_setup
will get the cdev from get_gadget_data, but configfs_composite_unbind
will set gadget data as NULL, so the NULL pointer issue occurs.
This concurrent is hard to reproduce by native kernel, but can be
reproduced by android kernel.

In this commit, we introduce one spinlock belongs to structure
gadget_info since we can't use the same spinlock in usb_composite_dev
due to exclusive running together between composite_setup and
configfs_composite_unbind. And one bit flag 'unbind' to indicate the
code is at unbind routine, this bit is needed due to we release the
lock at during configfs_composite_unbind sometimes, and composite_setup
may be run at that time.

Several oops:

oops 1:
android_work: sent uevent USB_STATE=CONNECTED
configfs-gadget gadget: super-speed config #1: b
android_work: sent uevent USB_STATE=CONFIGURED
init: Received control message 'start' for 'adbd' from pid: 3515 (system_server)
Unable to handle kernel NULL pointer dereference at virtual address 0000002a
init: Received control message 'stop' for 'adbd' from pid: 3375 (/vendor/bin/hw/android.hardware.usb@1.1-servic)
Mem abort info:
Exception class = DABT (current EL), IL = 32 bits
SET = 0, FnV = 0
EA = 0, S1PTW = 0
Data abort info:
ISV = 0, ISS = 0x00000004
CM = 0, WnR = 0
user pgtable: 4k pages, 48-bit VAs, pgd = ffff8008f1b7f000
[000000000000002a] *pgd=0000000000000000
Internal error: Oops: 96000004 [#1] PREEMPT SMP
Modules linked in:
CPU: 4 PID: 2457 Comm: irq/125-5b11000 Not tainted 4.14.98-07846-g0b40a9b-dirty #16
Hardware name: Freescale i.MX8QM MEK (DT)
task: ffff8008f2a98000 task.stack: ffff00000b7b8000
PC is at composite_setup+0x44/0x1508
LR is at android_setup+0xb8/0x13c
pc : [<ffff0000089ffb3c>] lr : [<ffff000008a032fc>] pstate: 800001c5
sp : ffff00000b7bbb80
x29: ffff00000b7bbb80 x28: ffff8008f2a3c010
x27: 0000000000000001 x26: 0000000000000000 [1232/1897]
audit: audit_lost=25791 audit_rate_limit=5 audit_backlog_limit=64
x25: 00000000ffffffa1 x24: ffff8008f2a3c010
audit: rate limit exceeded
x23: 0000000000000409 x22: ffff000009c8e000
x21: ffff8008f7a8b428 x20: ffff00000afae000
x19: ffff0000089ff000 x18: 0000000000000000
x17: 0000000000000000 x16: ffff0000082b7c9c
x15: 0000000000000000 x14: f1866f5b952aca46
x13: e35502e30d44349c x12: 0000000000000008
x11: 0000000000000008 x10: 0000000000000a30
x9 : ffff00000b7bbd00 x8 : ffff8008f2a98a90
x7 : ffff8008f27a9c90 x6 : 0000000000000001
x5 : 0000000000000000 x4 : 0000000000000001
x3 : 0000000000000000 x2 : 0000000000000006
x1 : ffff0000089ff8d0 x0 : 732a010310b9ed00

X7: 0xffff8008f27a9c10:
9c10 00000002 00000000 00000001 00000000 13110000 ffff0000 00000002 00208040
9c30 00000000 00000000 00000000 00000000 00000000 00000005 00000029 00000000
9c50 00051778 00000001 f27a8e00 ffff8008 00000005 00000000 00000078 00000078
9c70 00000078 00000000 09031d48 ffff0000 00100000 00000000 00400000 00000000
9c90 00000001 00000000 00000000 00000000 00000000 00000000 ffefb1a0 ffff8008
9cb0 f27a9ca8 ffff8008 00000000 00000000 b9d88037 00000173 1618a3eb 00000001
9cd0 870a792a 0000002e 16188fe6 00000001 0000242b 00000000 00000000 00000000
using random self ethernet address
9cf0 019a4646 00000000 000547f3 00000000 ecfd6c33 00000002 00000000
using random host ethernet address
00000000

X8: 0xffff8008f2a98a10:
8a10 00000000 00000000 f7788d00 ffff8008 00000001 00000000 00000000 00000000
8a30 eb218000 ffff8008 f2a98000 ffff8008 f2a98000 ffff8008 09885000 ffff0000
8a50 f34df480 ffff8008 00000000 00000000 f2a98648 ffff8008 09c8e000 ffff0000
8a70 fff2c800 ffff8008 09031d48 ffff0000 0b7bbd00 ffff0000 0b7bbd00 ffff0000
8a90 080861bc ffff0000 00000000 00000000 00000000 00000000 00000000 00000000
8ab0 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
8ad0 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
8af0 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000

X21: 0xffff8008f7a8b3a8:
b3a8 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
b3c8 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
b3e8 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
b408 00000000 00000000 00000000 00000000 00000000 00000000 00000001 00000000
b428 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
b448 0053004d 00540046 00300031 00010030 eb07b520 ffff8008 20011201 00000003
b468 e418d109 0104404e 00010302 00000000 eb07b558 ffff8008 eb07b558 ffff8008
b488 f7a8b488 ffff8008 f7a8b488 ffff8008 f7a8b300 ffff8008 00000000 00000000

X24: 0xffff8008f2a3bf90:
bf90 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
bfb0 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
bfd0 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
bff0 00000000 00000000 00000000 00000000 f76c8010 ffff8008 f76c8010 ffff8008
c010 00000000 00000000 f2a3c018 ffff8008 f2a3c018 ffff8008 08a067dc ffff0000
c030 f2a5a000 ffff8008 091c3650 ffff0000 f716fd18 ffff8008 f716fe30 ffff8008
c050 f2ce4a30 ffff8008 00000000 00000005 00000000 00000000 095d1568 ffff0000
c070 f76c8010 ffff8008 f2ce4b00 ffff8008 095cac68 ffff0000 f2a5a028 ffff8008

X28: 0xffff8008f2a3bf90:
bf90 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
bfb0 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
bfd0 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
bff0 00000000 00000000 00000000 00000000 f76c8010 ffff8008 f76c8010 ffff8008
c010 00000000 00000000 f2a3c018 ffff8008 f2a3c018 ffff8008 08a067dc ffff0000
c030 f2a5a000 ffff8008 091c3650 ffff0000 f716fd18 ffff8008 f716fe30 ffff8008
c050 f2ce4a30 ffff8008 00000000 00000005 00000000 00000000 095d1568 ffff0000
c070 f76c8010 ffff8008 f2ce4b00 ffff8008 095cac68 ffff0000 f2a5a028 ffff8008

Process irq/125-5b11000 (pid: 2457, stack limit = 0xffff00000b7b8000)
Call trace:
Exception stack(0xffff00000b7bba40 to 0xffff00000b7bbb80)
ba40: 732a010310b9ed00 ffff0000089ff8d0 0000000000000006 0000000000000000
ba60: 0000000000000001 0000000000000000 0000000000000001 ffff8008f27a9c90
ba80: ffff8008f2a98a90 ffff00000b7bbd00 0000000000000a30 0000000000000008
baa0: 0000000000000008 e35502e30d44349c f1866f5b952aca46 0000000000000000
bac0: ffff0000082b7c9c 0000000000000000 0000000000000000 ffff0000089ff000
bae0: ffff00000afae000 ffff8008f7a8b428 ffff000009c8e000 0000000000000409
bb00: ffff8008f2a3c010 00000000ffffffa1 0000000000000000 0000000000000001
bb20: ffff8008f2a3c010 ffff00000b7bbb80 ffff000008a032fc ffff00000b7bbb80
bb40: ffff0000089ffb3c 00000000800001c5 ffff00000b7bbb80 732a010310b9ed00
bb60: ffffffffffffffff ffff0000080f777c ffff00000b7bbb80 ffff0000089ffb3c
[<ffff0000089ffb3c>] composite_setup+0x44/0x1508
[<ffff000008a032fc>] android_setup+0xb8/0x13c
[<ffff0000089bd9a8>] cdns3_ep0_delegate_req+0x44/0x70
[<ffff0000089bdff4>] cdns3_check_ep0_interrupt_proceed+0x33c/0x654
[<ffff0000089bca44>] cdns3_device_thread_irq_handler+0x4b0/0x4bc
[<ffff0000089b77b4>] cdns3_thread_irq+0x48/0x68
[<ffff000008145bf0>] irq_thread_fn+0x28/0x88
[<ffff000008145e38>] irq_thread+0x13c/0x228
[<ffff0000080fed70>] kthread+0x104/0x130
[<ffff000008085064>] ret_from_fork+0x10/0x18

oops2:
composite_disconnect: Calling disconnect on a Gadget that is not connected
android_work: did not send uevent (0 0 (null))
init: Received control message 'stop' for 'adbd' from pid: 3359 (/vendor/bin/hw/android.hardware.usb@1.1-service.imx)
init: Sending signal 9 to service 'adbd' (pid 22343) process group...
------------[ cut here ]------------
audit: audit_lost=180038 audit_rate_limit=5 audit_backlog_limit=64
audit: rate limit exceeded
WARNING: CPU: 0 PID: 3468 at kernel_imx/drivers/usb/gadget/composite.c:2009 composite_disconnect+0x80/0x88
Modules linked in:
CPU: 0 PID: 3468 Comm: HWC-UEvent-Thre Not tainted 4.14.98-07846-g0b40a9b-dirty #16
Hardware name: Freescale i.MX8QM MEK (DT)
task: ffff8008f2349c00 task.stack: ffff00000b0a8000
PC is at composite_disconnect+0x80/0x88
LR is at composite_disconnect+0x80/0x88
pc : [<ffff0000089ff9b0>] lr : [<ffff0000089ff9b0>] pstate: 600001c5
sp : ffff000008003dd0
x29: ffff000008003dd0 x28: ffff8008f2349c00
x27: ffff000009885018 x26: ffff000008004000
Timeout for IPC response!
x25: ffff000009885018 x24: ffff000009c8e280
x23: ffff8008f2d98010 x22: 00000000000001c0
x21: ffff8008f2d98394 x20: ffff8008f2d98010
x19: 0000000000000000 x18: 0000e3956f4f075a
fxos8700 4-001e: i2c block read acc failed
x17: 0000e395735727e8 x16: ffff00000829f4d4
x15: ffffffffffffffff x14: 7463656e6e6f6320
x13: 746f6e2009090920 x12: 7369207461687420
x11: 7465676461472061 x10: 206e6f207463656e
x9 : 6e6f637369642067 x8 : ffff000009c8e280
x7 : ffff0000086ca6cc x6 : ffff000009f15e78
x5 : 0000000000000000 x4 : 0000000000000000
x3 : ffffffffffffffff x2 : c3f28b86000c3900
x1 : c3f28b86000c3900 x0 : 000000000000004e

X20: 0xffff8008f2d97f90:
7f90 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
7fb0 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
libprocessgroup: Failed to kill process cgroup uid 0 pid 22343 in 215ms, 1 processes remain
7fd0
Timeout for IPC response!
00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
using random self ethernet address
7ff0 00000000 00000000 00000000 00000000 f76c8010 ffff8008 f76c8010 ffff8008
8010 00000100 00000000 f2d98018 ffff8008 f2d98018 ffff8008 08a067dc
using random host ethernet address
ffff0000
8030 f206d800 ffff8008 091c3650 ffff0000 f7957b18 ffff8008 f7957730 ffff8008
8050 f716a630 ffff8008 00000000 00000005 00000000 00000000 095d1568 ffff0000
8070 f76c8010 ffff8008 f716a800 ffff8008 095cac68 ffff0000 f206d828 ffff8008

X21: 0xffff8008f2d98314:
8314 ffff8008 00000000 00000000 00000000 00000000 00000000 00000000 00000000
8334 00000000 00000000 00000000 00000000 00000000 08a04cf4 ffff0000 00000000
8354 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
8374 00000000 00000000 00000000 00001001 00000000 00000000 00000000 00000000
8394 e4bbe4bb 0f230000 ffff0000 0afae000 ffff0000 ae001000 00000000 f206d400
Timeout for IPC response!
83b4 ffff8008 00000000 00000000 f7957b18 ffff8008 f7957718 ffff8008 f7957018
83d4 ffff8008 f7957118 ffff8008 f7957618 ffff8008 f7957818 ffff8008 f7957918
83f4 ffff8008 f7957d18 ffff8008 00000000 00000000 00000000 00000000 00000000

X23: 0xffff8008f2d97f90:
7f90 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
7fb0 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
7fd0 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
7ff0 00000000 00000000 00000000 00000000 f76c8010 ffff8008 f76c8010 ffff8008
8010 00000100 00000000 f2d98018 ffff8008 f2d98018 ffff8008 08a067dc ffff0000
8030 f206d800 ffff8008 091c3650 ffff0000 f7957b18 ffff8008 f7957730 ffff8008
8050 f716a630 ffff8008 00000000 00000005 00000000 00000000 095d1568 ffff0000
8070 f76c8010 ffff8008 f716a800 ffff8008 095cac68 ffff0000 f206d828 ffff8008

X28: 0xffff8008f2349b80:
9b80 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
9ba0 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
9bc0 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
9be0 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
9c00 00000022 00000000 ffffffff ffffffff 00010001 00000000 00000000 00000000
9c20 0b0a8000 ffff0000 00000002 00404040 00000000 00000000 00000000 00000000
9c40 00000001 00000000 00000001 00000000 001ebd44 00000001 f390b800 ffff8008
9c60 00000000 00000001 00000070 00000070 00000070 00000000 09031d48 ffff0000

Call trace:
Exception stack(0xffff000008003c90 to 0xffff000008003dd0)
3c80: 000000000000004e c3f28b86000c3900
3ca0: c3f28b86000c3900 ffffffffffffffff 0000000000000000 0000000000000000
3cc0: ffff000009f15e78 ffff0000086ca6cc ffff000009c8e280 6e6f637369642067
3ce0: 206e6f207463656e 7465676461472061 7369207461687420 746f6e2009090920
3d00: 7463656e6e6f6320 ffffffffffffffff ffff00000829f4d4 0000e395735727e8
3d20: 0000e3956f4f075a 0000000000000000 ffff8008f2d98010 ffff8008f2d98394
3d40: 00000000000001c0 ffff8008f2d98010 ffff000009c8e280 ffff000009885018
3d60: ffff000008004000 ffff000009885018 ffff8008f2349c00 ffff000008003dd0
3d80: ffff0000089ff9b0 ffff000008003dd0 ffff0000089ff9b0 00000000600001c5
3da0: ffff8008f33f2cd8 0000000000000000 0000ffffffffffff 0000000000000000
init: Received control message 'start' for 'adbd' from pid: 3359 (/vendor/bin/hw/android.hardware.usb@1.1-service.imx)
3dc0: ffff000008003dd0 ffff0000089ff9b0
[<ffff0000089ff9b0>] composite_disconnect+0x80/0x88
[<ffff000008a044d4>] android_disconnect+0x3c/0x68
[<ffff0000089ba9f8>] cdns3_device_irq_handler+0xfc/0x2c8
[<ffff0000089b84c0>] cdns3_irq+0x44/0x94
[<ffff00000814494c>] __handle_irq_event_percpu+0x60/0x24c
[<ffff000008144c0c>] handle_irq_event+0x58/0xc0
[<ffff00000814873c>] handle_fasteoi_irq+0x98/0x180
[<ffff000008143a10>] generic_handle_irq+0x24/0x38
[<ffff000008144170>] __handle_domain_irq+0x60/0xac
[<ffff0000080819c4>] gic_handle_irq+0xd4/0x17c

Cc: Andrzej Pietrasiewicz <andrzejtp2010@gmail.com>
Signed-off-by: Peter Chen <peter.chen@nxp.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

usb: gadget: configfs: avoid spaces for indentation

This fixes the following checkpatch error:

ERROR: code indent should use tabs where possible

Here, spaces are replaced by a tab in 2 lines.

Signed-off-by: Parth Y Shah <sparth1292@gmail.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

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: configfs: make config_item_type const

Make config_item_type structures const as they are either passed to a
function having the argument as const or stored in the const "ci_type"
field of a config_item structure.

Done using Coccinelle.

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: configfs: Fix memory leak of interface directory data

Kmemleak checking configuration reports a memory leak in
usb_os_desc_prepare_interf_dir function when rndis function
instance is freed and then allocated again. For example, this
happens with FunctionFS driver with RNDIS function enabled
when "ffs-test" test application is run several times in a row.

The data for intermediate "os_desc" group for interface directories
is allocated as a single VLA chunk and (after a change of default
groups handling) is not ever freed and actually not stored anywhere
besides inside a list of default groups of a parent group.

The fix is to make usb_os_desc_prepare_interf_dir function return
a pointer to allocated data (as a pointer to the first VLA item)
instead of (an unused) integer and to make the caller component
(currently the only one is RNDIS function) responsible for storing
the pointer and freeing the memory when appropriate.

Fixes: 1ae1602de028 ("configfs: switch ->default groups to a linked list")
Cc: stable@vger.kernel.org
Signed-off-by: Andrew Gabbasov <andrew_gabbasov@mentor.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

usb: gadget: configfs: use hexadecimal values and new line

Other unsigned properties return hexadecimal values, follow this
convention when printing b_vendor_code too. Also add newlines to
the OS Descriptor support related properties, like other sysfs
files use.

Reviewed-by: Krzysztof Opasiak <k.opasiak@samsung.com>
Signed-off-by: Stefan Agner <stefan@agner.ch>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

usb: gadget: configfs: make qw_sign attribute symmetric

Currently qw_sign requires UTF-8 character to set, but returns UTF-16
when read. This isn't obvious when simply using cat since the null
characters are not visible, but hexdump unveils the true string:

# echo MSFT100 > os_desc/qw_sign
# hexdump -C os_desc/qw_sign
00000000 4d 00 53 00 46 00 54 00 31 00 30 00 30 00 |M.S.F.T.1.0.0.|

Make qw_sign symmetric by returning an UTF-8 string too. Also follow
common convention and add a new line at the end.

Reviewed-by: Krzysztof Opasiak <k.opasiak@samsung.com>
Signed-off-by: Stefan Agner <stefan@agner.ch>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

usb: gadget: configs: plug memory leak

When binding a gadget to a device, "name" is stored in gi->udc_name, but
this does not happen when unregistering and the string is leaked.

Signed-off-by: John Keeping <john@metanate.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

fs: configfs: don't return anything from drop_link

Documentation/filesystems/configfs/configfs.txt says:

"When unlink(2) is called on the symbolic link, the source item is
notified via the ->drop_link() method. Like the ->drop_item() method,
this is a void function and cannot return failure."

The ->drop_item() is indeed a void function, the ->drop_link() is
actually not. This, together with the fact that the value of ->drop_link()
is silently ignored suggests, that it is the ->drop_link() return
type that should be corrected and changed to void.

This patch changes drop_link() signature and all its users.

Signed-off-by: Andrzej Pietrasiewicz <andrzej.p@samsung.com>
[hch: reverted reformatting of some code]
Signed-off-by: Christoph Hellwig <hch@lst.de>

usb: gadget: configfs: log function unbinding as debug

Disabling USB gadget functions configured through configfs is something
that can happen in normal use cases. Keep the existing log for this type
of event, but only as debug, not as an error.

Signed-off-by: Romain Izard <romain.izard.pro@gmail.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

usb: gadget: configfs: log function unbinding as information

Disabling USB gadget functions configured through configfs is something
that can happen in normal use cases. Keep the existing log for this type
of event, but only as information, not as an error.

Signed-off-by: Romain Izard <romain.izard.pro@gmail.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

usb: gadget: configfs: add mutex lock before unregister gadget

There may be a race condition if f_fs calls unregister_gadget_item in
ffs_closed() when unregister_gadget is called by UDC store at the same time.
this leads to a kernel NULL pointer dereference:

[ 310.644928] Unable to handle kernel NULL pointer dereference at virtual address 00000004
[ 310.645053] init: Service 'adbd' is being killed...
[ 310.658938] pgd = c9528000
[ 310.662515] [00000004] *pgd=19451831, *pte=00000000, *ppte=00000000
[ 310.669702] Internal error: Oops: 817 [#1] PREEMPT SMP ARM
[ 310.675211] Modules linked in:
[ 310.678294] CPU: 0 PID: 1537 Comm: ->transport Not tainted 4.1.15-03725-g793404c #2
[ 310.685958] Hardware name: Freescale i.MX6 Quad/DualLite (Device Tree)
[ 310.692493] task: c8e24200 ti: c945e000 task.ti: c945e000
[ 310.697911] PC is at usb_gadget_unregister_driver+0xb4/0xd0
[ 310.703502] LR is at __mutex_lock_slowpath+0x10c/0x16c
[ 310.708648] pc : [<c075efc0>] lr : [<c0bfb0bc>] psr: 600f0113
<snip..>
[ 311.565585] [<c075efc0>] (usb_gadget_unregister_driver) from [<c075e2b8>] (unregister_gadget_item+0x1c/0x34)
[ 311.575426] [<c075e2b8>] (unregister_gadget_item) from [<c076fcc8>] (ffs_closed+0x8c/0x9c)
[ 311.583702] [<c076fcc8>] (ffs_closed) from [<c07736b8>] (ffs_data_reset+0xc/0xa0)
[ 311.591194] [<c07736b8>] (ffs_data_reset) from [<c07738ac>] (ffs_data_closed+0x90/0xd0)
[ 311.599208] [<c07738ac>] (ffs_data_closed) from [<c07738f8>] (ffs_ep0_release+0xc/0x14)
[ 311.607224] [<c07738f8>] (ffs_ep0_release) from [<c023e030>] (__fput+0x80/0x1d0)
[ 311.614635] [<c023e030>] (__fput) from [<c014e688>] (task_work_run+0xb0/0xe8)
[ 311.621788] [<c014e688>] (task_work_run) from [<c010afdc>] (do_work_pending+0x7c/0xa4)
[ 311.629718] [<c010afdc>] (do_work_pending) from [<c010770c>] (work_pending+0xc/0x20)

for functions using functionFS, i.e. android adbd will close /dev/usb-ffs/adb/ep0
when usb IO thread fails, but switch adb from on to off also triggers write
"none" > UDC. These 2 operations both call unregister_gadget, which will lead
to the panic above.

add a mutex before calling unregister_gadget for api used in f_fs.

Signed-off-by: Winter Wang <wente.wang@nxp.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

usb: gadget: Fix binding to UDC via configfs interface

By default user could store only valid UDC name in configfs UDC
attr by doing:

echo $UDC_NAME > UDC

Commit (855ed04 "usb: gadget: udc-core: independent registration of
gadgets and gadget drivers") broke this behavior and allowed to store
any arbitrary string in UDC file and udc core was waiting for such
controller to appear.

echo "any arbitrary string here" > UDC

This commit fix this by adding a flag which prevents configfs
gadget from being added to list of pending drivers if UDC with
given name has not been found.

Signed-off-by: Krzysztof Opasiak <k.opasiak@samsung.com>
Signed-off-by: Felipe Balbi <felipe.balbi@linux.intel.com>

configfs: switch ->default groups to a linked list

Replace the current NULL-terminated array of default groups with a linked
list. This gets rid of lots of nasty code to size and/or dynamically
allocate the array.

While we're at it also provide a conveniant helper to remove the default
groups.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Felipe Balbi <balbi@kernel.org> [drivers/usb/gadget]
Acked-by: Joel Becker <jlbec@evilplan.org>
Acked-by: Nicholas Bellinger <nab@linux-iscsi.org>
Reviewed-by: Sagi Grimberg <sagig@mellanox.com>

usb: gadget: Update config for SuperSpeedPlus

When a function is added to a configuration with usb_add_function(), the
configuration speed flags are updated. These flags indicate for which
speeds the configuration is valid for.

This patch adds a flag in the configuration for SuperSpeedPlus and
also updates this based on the existence of ssp_descriptors.

Signed-off-by: John Youn <johnyoun@synopsys.com>
Signed-off-by: Felipe Balbi <balbi@kernel.org>

usb: gadget: configfs: pass UDC name via usb_gadget_driver struct

Now when udc-core supports binding to specific UDC by passing
its name via 'udc_name' member of usb_gadget_driver struct,
switch to this generic approach.

Tested-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Ruslan Bilovol <ruslan.bilovol@gmail.com>
[rebased and fixed checkpatch issues]
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Tested-by: Peter Chen <peter.chen@freescale.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

usb-gadget: 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: configfs: allocate and init otg descriptor by otg capabilities

Allocate and initialize usb otg descriptor according to gadget otg
capabilities, add it for each usb configurations, free it while
composite unbind. If otg capability is not defined, keep its otg
descriptor unchanged.

Signed-off-by: Li Jun <jun.li@freescale.com>
Reviewed-by: Roger Quadros <rogerq@ti.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

configfs: fix kernel infoleak through user-controlled format string

Some modules call config_item_init_type_name() and config_group_init_type_name()
with parameter "name" directly controlled by userspace. These two
functions call config_item_set_name() with this name used as a format
string, which can be used to leak information such as content of the
stack to userspace.

For example, make_netconsole_target() in netconsole module calls
config_item_init_type_name() with the name of a newly-created directory.
This means that the following commands give some unexpected output, with
configfs mounted in /sys/kernel/config/ and on a system with a
configured eth0 ethernet interface:

# modprobe netconsole
# mkdir /sys/kernel/config/netconsole/target_%lx
# echo eth0 > /sys/kernel/config/netconsole/target_%lx/dev_name
# echo 1 > /sys/kernel/config/netconsole/target_%lx/enabled
# echo eth0 > /sys/kernel/config/netconsole/target_%lx/dev_name
# dmesg |tail -n1
[ 142.697668] netconsole: target (target_ffffffffc0ae8080) is
enabled, disable to update parameters

The directory name is correct but %lx has been interpreted in the
internal item name, displayed here in the error message used by
store_dev_name() in drivers/net/netconsole.c.

To fix this, update every caller of config_item_set_name to use "%s"
when operating on untrusted input.

This issue was found using -Wformat-security gcc flag, once a __printf
attribute has been added to config_item_set_name().

Signed-off-by: Nicolas Iooss <nicolas.iooss_linux@m4x.org>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Felipe Balbi <balbi@ti.com>
Acked-by: Joel Becker <jlbec@evilplan.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

usb: gadget: configfs: Fix interfaces array NULL-termination

memset() to 0 interfaces array before reusing
usb_configuration structure.

This commit fix bug:

ln -s functions/acm.1 configs/c.1
ln -s functions/acm.2 configs/c.1
ln -s functions/acm.3 configs/c.1
echo "UDC name" > UDC
echo "" > UDC
rm configs/c.1/acm.*
rmdir functions/*
mkdir functions/ecm.usb0
ln -s functions/ecm.usb0 configs/c.1
echo "UDC name" > UDC

[ 82.220969] Unable to handle kernel NULL pointer dereference at virtual address 00000000
[ 82.229009] pgd = c0004000
[ 82.231698] [00000000] *pgd=00000000
[ 82.235260] Internal error: Oops: 17 [#1] PREEMPT SMP ARM
[ 82.240638] Modules linked in:
[ 82.243681] CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.0.0-rc2 #39
[ 82.249926] Hardware name: SAMSUNG EXYNOS (Flattened Device Tree)
[ 82.256003] task: c07cd2f0 ti: c07c8000 task.ti: c07c8000
[ 82.261393] PC is at composite_setup+0xe3c/0x1674
[ 82.266073] LR is at composite_setup+0xf20/0x1674
[ 82.270760] pc : [<c03510d4>] lr : [<c03511b8>] psr: 600001d3
[ 82.270760] sp : c07c9df0 ip : c0806448 fp : ed8c9c9c
[ 82.282216] r10: 00000001 r9 : 00000000 r8 : edaae918
[ 82.287425] r7 : ed551cc0 r6 : 00007fff r5 : 00000000 r4 : ed799634
[ 82.293934] r3 : 00000003 r2 : 00010002 r1 : edaae918 r0 : 0000002e
[ 82.300446] Flags: nZCv IRQs off FIQs off Mode SVC_32 ISA ARM Segment kernel
[ 82.307910] Control: 10c5387d Table: 6bc1804a DAC: 00000015
[ 82.313638] Process swapper/0 (pid: 0, stack limit = 0xc07c8210)
[ 82.319627] Stack: (0xc07c9df0 to 0xc07ca000)
[ 82.323969] 9de0: 00000000 c06e65f4 00000000 c07c9f68
[ 82.332130] 9e00: 00000067 c07c59ac 000003f7 edaae918 ed8c9c98 ed799690 eca2f140 200001d3
[ 82.340289] 9e20: ee79a2d8 c07c9e88 c07c5304 ffff55db 00010002 edaae810 edaae860 eda96d50
[ 82.348448] 9e40: 00000009 ee264510 00000007 c07ca444 edaae860 c0340890 c0827a40 ffff55e0
[ 82.356607] 9e60: c0827a40 eda96e40 ee264510 edaae810 00000000 edaae860 00000007 c07ca444
[ 82.364766] 9e80: edaae860 c0354170 c03407dc c033db4c edaae810 00000000 00000000 00000010
[ 82.372925] 9ea0: 00000032 c0341670 00000000 00000000 00000001 eda96e00 00000000 00000000
[ 82.381084] 9ec0: 00000000 00000032 c0803a23 ee1aa840 00000001 c005d54c 249e2450 00000000
[ 82.389244] 9ee0: 200001d3 ee1aa840 ee1aa8a0 ed84f4c0 00000000 c07c9f68 00000067 c07c59ac
[ 82.397403] 9f00: 00000000 c005d688 ee1aa840 ee1aa8a0 c07db4b4 c006009c 00000032 00000000
[ 82.405562] 9f20: 00000001 c005ce20 c07c59ac c005cf34 f002000c c07ca780 c07c9f68 00000057
[ 82.413722] 9f40: f0020000 413fc090 00000001 c00086b4 c000f804 60000053 ffffffff c07c9f9c
[ 82.421880] 9f60: c0803a20 c0011fc0 00000000 00000000 c07c9fb8 c001bee0 c07ca4f0 c057004c
[ 82.430040] 9f80: c07ca4fc c0803a20 c0803a20 413fc090 00000001 00000000 01000000 c07c9fb0
[ 82.438199] 9fa0: c000f800 c000f804 60000053 ffffffff 00000000 c0050e70 c0803bc0 c0783bd8
[ 82.446358] 9fc0: ffffffff ffffffff c0783664 00000000 00000000 c07b13e8 00000000 c0803e54
[ 82.454517] 9fe0: c07ca480 c07b13e4 c07ce40c 4000406a 00000000 40008074 00000000 00000000
[ 82.462689] [<c03510d4>] (composite_setup) from [<c0340890>] (s3c_hsotg_complete_setup+0xb4/0x418)
[ 82.471626] [<c0340890>] (s3c_hsotg_complete_setup) from [<c0354170>] (usb_gadget_giveback_request+0xc/0x10)
[ 82.481429] [<c0354170>] (usb_gadget_giveback_request) from [<c033db4c>] (s3c_hsotg_complete_request+0xcc/0x12c)
[ 82.491583] [<c033db4c>] (s3c_hsotg_complete_request) from [<c0341670>] (s3c_hsotg_irq+0x4fc/0x558)
[ 82.500614] [<c0341670>] (s3c_hsotg_irq) from [<c005d54c>] (handle_irq_event_percpu+0x50/0x150)
[ 82.509291] [<c005d54c>] (handle_irq_event_percpu) from [<c005d688>] (handle_irq_event+0x3c/0x5c)
[ 82.518145] [<c005d688>] (handle_irq_event) from [<c006009c>] (handle_fasteoi_irq+0xd4/0x18c)
[ 82.526650] [<c006009c>] (handle_fasteoi_irq) from [<c005ce20>] (generic_handle_irq+0x20/0x30)
[ 82.535242] [<c005ce20>] (generic_handle_irq) from [<c005cf34>] (__handle_domain_irq+0x6c/0xdc)
[ 82.543923] [<c005cf34>] (__handle_domain_irq) from [<c00086b4>] (gic_handle_irq+0x2c/0x6c)
[ 82.552256] [<c00086b4>] (gic_handle_irq) from [<c0011fc0>] (__irq_svc+0x40/0x74)
[ 82.559716] Exception stack(0xc07c9f68 to 0xc07c9fb0)
[ 82.564753] 9f60: 00000000 00000000 c07c9fb8 c001bee0 c07ca4f0 c057004c
[ 82.572913] 9f80: c07ca4fc c0803a20 c0803a20 413fc090 00000001 00000000 01000000 c07c9fb0
[ 82.581069] 9fa0: c000f800 c000f804 60000053 ffffffff
[ 82.586113] [<c0011fc0>] (__irq_svc) from [<c000f804>] (arch_cpu_idle+0x30/0x3c)
[ 82.593491] [<c000f804>] (arch_cpu_idle) from [<c0050e70>] (cpu_startup_entry+0x128/0x1a4)
[ 82.601740] [<c0050e70>] (cpu_startup_entry) from [<c0783bd8>] (start_kernel+0x350/0x3bc)
[ 82.609890] Code: 0a000002 e3530005 05975010 15975008 (e5953000)
[ 82.615965] ---[ end trace f57d5f599a5f1bfa ]---

Most of kernel code assume that interface array in
struct usb_configuration is NULL terminated.

When gadget is composed with configfs configuration
structure may be reused for different functions set.

This bug happens because purge_configs_funcs() sets
only next_interface_id to 0. Interface array still
contains pointers to already freed interfaces. If in
second try we add less interfaces than earlier we
may access unallocated memory when trying to get
interface descriptors.

Signed-off-by: Krzysztof Opasiak <k.opasiak@samsung.com>
Cc: <stable@vger.kernel.org> # 3.10+
Signed-off-by: Felipe Balbi <balbi@ti.com>

usb: gadget: configfs: don't NUL-terminate (sub)compatible ids

The "Extended Compat ID OS Feature Descriptor Specification" does not
require the (sub)compatible ids to be NUL-terminated, because they
are placed in a fixed-size buffer and only unused parts of it should
contain NULs. If the buffer is fully utilized, there is no place for NULs.

Consequently, the code which uses desc->ext_compat_id never expects the
data contained to be NUL terminated.

If the compatible id is stored after sub-compatible id, and the compatible
id is full length (8 bytes), the (useless) NUL terminator overwrites the
first byte of the sub-compatible id.

If the sub-compatible id is full length (8 bytes), the (useless) NUL
terminator ends up out of the buffer. The situation can happen in the RNDIS
function, where the buffer is a part of struct f_rndis_opts. The next
member of struct f_rndis_opts is a mutex, so its first byte gets
overwritten. The said byte is a part of a mutex'es member which contains
the information on whether the muext is locked or not. This can lead to a
deadlock, because, in a configfs-composed gadget when a function is linked
into a configuration with config_usb_cfg_link(), usb_get_function()
is called, which then calls rndis_alloc(), which tries locking the same
mutex and (wrongly) finds it already locked.

This patch eliminates NUL terminating of the (sub)compatible id.

Cc: <stable@vger.kernel.org> # v3.16+
Fixes: da4243145fb1: "usb: gadget: configfs: OS Extended Compatibility descriptors support"
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Andrzej Pietrasiewicz <andrzej.p@samsung.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

usb: gadget: udc: core: prepend udc_attach_driver with usb_

No functional changes, just adding a prefix
which should have been there from the start.

Signed-off-by: Felipe Balbi <balbi@ti.com>

usb: gadget: configfs: add suspend/resume

USB gadgets composed with configfs lack suspend and resume
methods. This patch uses composite_suspend()/composite_resume()
the same way e.g. composite_setup() or composite_disconnect()
are used in a configfs-based gadget.

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

usb: gadget: configfs: add reset API at usb_gadget_driver

Add reset API at usb_gadget_driver, it calls disconnect handler currently,
but may do different things in future.

Acked-by: Alan Stern <stern@rowland.harvard.edu>
Signed-off-by: Peter Chen <peter.chen@freescale.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

usb: gadget: Use kmemdup instead of kmalloc + memcpy

This issue was reported by coccicheck using the semantic patch
at scripts/coccinelle/api/memdup.cocci

Signed-off-by: Benoit Taine <benoit.taine@lip6.fr>
Signed-off-by: Felipe Balbi <balbi@ti.com>

usb: gadget: OS descriptors: provide interface directory names

Function's interface directories need to be created when the function
directory is created, but interface numbers are not known until
the gadget is ready and bound to udc, so we cannot use numbers
as part of interface directory names.
Let the client decide what names to use.

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

usb: gadget: OS descriptors configfs cleanup

A number of variables serve a generic purpose of handling
"compatible id" and "subcompatible id", but the names suggest they
are for rndis only. Rename to reflect variables' purpose.

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

usb: gadget: configfs: OS Extended Properties descriptors support

Add handling of OS Extended Properties descriptors from configfs interface.
One kind of "OS Descriptors" are "Extended Properties" descriptors, which
need to be specified per interface or per group of interfaces described
by an IAD. This patch adds support for creating subdirectories
in interface.<n> directory located in the function's directory.
Names of subdirectories created become names of properties.
Each property contains two attributes: "type" and "data".
The type can be a numeric value 1..7 while data is a blob interpreted
depending on the type specified.
The types are:
1 - unicode string
2 - unicode string with environment variables
3 - binary
4 - little-endian 32-bit
5 - big-endian 32-bit
6 - unicode string with a symbolic link
7 - multiple unicode strings

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

usb: gadget: configfs: OS Extended Compatibility descriptors support

Add handling of OS Extended Compatibility descriptors from configfs interface.
Hosts which expect the "OS Descriptors" ask only for configurations @ index 0,
but linux-based USB devices can provide more than one configuration.
This patch adds marking one of gadget's configurations the configuration
to be reported at index 0, regardless of the actual sequence of usb_add_config
invocations used for adding the configurations. The configuration is selected
by creating a symbolic link pointing to it from the "os_desc" directory
located at the top of a gadget's directory hierarchy.

One kind of "OS Descriptors" are "Extended Compatibility Descriptors",
which need to be specified per interface. This patch adds interface.<n>
directory in function's configfs directory to represent each interface
defined by the function. Each interface's directory contains two attributes:
"compatible_id" and "sub_compatible_id", which represent 8-byte
strings to be reported to the host as the "Compatible ID" and "Sub Compatible
ID".

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

usb: gadget: configfs: OS String support

Add handling of OS String extension from the configfs interface.
A directory "os_desc" is added at the top level of a gadget's
directories hierarchy. In the "os_desc" directory there are
three attributes: "use", "b_vendor_code" and "qw_sign".
If "use" contains "0" the OS string is not reported to the host.
"b_vendor_code" contains a one-byte value which is used
for custom per-device and per-interface requests.
"qw_sign" contains an identifier to be reported as the "OS String"
proper.

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

usb: gadget: configfs: fix typo

%s/atleast/at least

Signed-off-by: Peter Chen <peter.chen@freescale.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

usb: gadget: only GPL drivers in the gadget and phy framework

We only support GPL drivers in the USB Gadget Framework,
it sounds correct to make all exported symbols GPL too.

Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Felipe Balbi <balbi@ti.com>

usb: gadget: configfs: include appropriate header file in configfs.c

Include appropriate header file drivers/usb/gadget/configfs.h in
gadget/configfs.c because function unregister_gadget_item() has its
prototype declaration in gadget/configfs.h.

This eliminates the following warning in gadget/configfs.c:
drivers/usb/gadget/configfs.c:994:6: warning: no previous prototype for ‘unregister_gadget_item’ [-Wmissing-prototypes]

Signed-off-by: Rashika Kheria <rashika.kheria@gmail.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Signed-off-by: Felipe Balbi <balbi@ti.com>

usb: gadget: configfs: allow setting function instance's name

USB function's configfs config group is created in a generic way in
usb/gadget/configfs.c:function_make(), which in turn delegates actual
allocation and setup of the USB function instance to a particular
implementation, e.g. in f_acm.c. The said implementation does its job
in a parameter-less function e.g. acm_alloc_instance(), which results
in creating an unnamed config group, whose name is set later in
function_make(). function_make() creates the name by parsing a string
of the form:

<function name>.<instance name>

which comes from userspace as a parameter to mkdir invocation.

Up to now only <function name> has been used, while <instance name>
has been ignored. This patch adds a set_inst_name() operation to
struct usb_function_instance which allows passing the <instance name>
from function_make() so that it is not ignored. It is entirely up to the
implementor of set_inst_name() what to do with the <instance name>.

In a typical case, the struct usb_function_instance is embedded in a
larger struct which is retrieved in set_inst_name() with container_of(),
and the larger struct contains a field to store the <instance name>.

Signed-off-by: Andrzej Pietrasiewicz <andrzej.p@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Acked-by: Michal Nazarewicz <mina86@mina86.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

usb: gadget: configfs: add a method to unregister the gadget

Add a method to unregister the gadget using its config_item.

There can be functions (e.g. mass storage), which in some circumstances
need the gadget stopped. Add a method of stopping the gadget.

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

usb: gadget: Use ERR_CAST inlined function instead of ERR_PTR(PTR_ERR(...))

trivial patch converting ERR_PTR(PTR_ERR()) into ERR_CAST().
No functional changes.

Signed-off-by: Duan Jiong <duanj.fnst@cn.fujitsu.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>

usb: gadget: configfs: keep a function if it is not successfully added

If usb_add_function() fails then the currently processed function
is already not in the list in struct config_usb_cfg, and neither is it
in the list in struct usb_configuration. At the err_purge_funcs label the
purge_config_funcs() is called, which iterates over all configurations,
and in each configuration it iterates over all _successfully_ added
functions, and moves them back from the list in struct usb_configuration
to the list in struct config_usb_cfg. BUT the function which has just
failed adding and caused the unwind process is not taken care of and
is effectively lost.

This patch modifies the configfs_composite_bind() function so that if
the usb_add_function() fails, then the currently processed function
is returned to the list in struct config_usb_cfg.

It would be tempting to delay the list_del() in question after
usb_add_function() invocation, but a struct list_head (&f->list) cannot be
stored in more than one list at the same time, so the list_del() must
be called before usb_add_function(). Hence, the solution is to list_add()
after usb_add_function() in case of error.

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

usb: gadget: fix error return code in configfs_composite_bind()

Fix to return a negative error code in the go through all configs error
handling case instead of 0(usb_add_function() will overwrite ret to 0).
Also use error code from usb_gstrings_attach() in all strings init error
case instead of -EINVAL.

Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: Felipe Balbi <balbi@ti.com>

usb, gadget: use appropriate warning accessors

Use the appropriate WARN() and WARN_ON() accessors to avoid a build error
when CONFIG_BUG=n:

drivers/usb/gadget/configfs.c: In function 'config_usb_cfg_unlink':
drivers/usb/gadget/configfs.c:442:2: error: implicit declaration of function '__WARN_printf'
drivers/usb/gadget/configfs.c: In function 'configfs_do_nothing':
drivers/usb/gadget/configfs.c:733:2: error: implicit declaration of function '__WARN'

Reported-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: David Rientjes <rientjes@google.com>
Cc: Felipe Balbi <balbi@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

usb: gadget: the start of the configfs interface

|# modprobe dummy_hcd num=2
|# modprobe libcomposite

|# lsmod
|Module Size Used by
|libcomposite 31648 0
|dummy_hcd 19871 0

|# mkdir /sys/kernel/config/usb_gadget/oha
|# cd /sys/kernel/config/usb_gadget/oha
|# mkdir configs/def.1
|# mkdir configs/def.2
|# mkdir functions/acm.ttyS1
|# mkdir strings/0x1
|mkdir: cannot create directory `strings/0x1': Invalid argument
|# mkdir strings/0x409
|# mkdir strings/1033
|mkdir: cannot create directory `strings/1033': File exists
|# mkdir strings/1032
|# mkdir configs/def.1/strings/0x409
|# mkdir configs/def.2/strings/0x409

|#find . -ls
| 975 0 drwxr-xr-x 5 root root 0 Dec 23 17:40 .
| 978 0 drwxr-xr-x 4 root root 0 Dec 23 17:43 ./strings
| 4100 0 drwxr-xr-x 2 root root 0 Dec 23 17:43 ./strings/1032
| 995 0 -rw-r--r-- 1 root root 4096 Dec 23 17:43 ./strings/1032/serialnumber
| 996 0 -rw-r--r-- 1 root root 4096 Dec 23 17:43 ./strings/1032/product
| 997 0 -rw-r--r-- 1 root root 4096 Dec 23 17:43 ./strings/1032/manufacturer
| 2002 0 drwxr-xr-x 2 root root 0 Dec 23 17:41 ./strings/0x409
| 998 0 -rw-r--r-- 1 root root 4096 Dec 23 17:43 ./strings/0x409/serialnumber
| 999 0 -rw-r--r-- 1 root root 4096 Dec 23 17:43 ./strings/0x409/product
| 1000 0 -rw-r--r-- 1 root root 4096 Dec 23 17:43 ./strings/0x409/manufacturer
| 977 0 drwxr-xr-x 4 root root 0 Dec 23 17:41 ./configs
| 4081 0 drwxr-xr-x 3 root root 0 Dec 23 17:41 ./configs/def.2
| 4082 0 drwxr-xr-x 3 root root 0 Dec 23 17:42 ./configs/def.2/strings
| 2016 0 drwxr-xr-x 2 root root 0 Dec 23 17:42 ./configs/def.2/strings/0x409
| 1001 0 -rw-r--r-- 1 root root 4096 Dec 23 17:43 ./configs/def.2/strings/0x409/configuration
| 1002 0 -rw-r--r-- 1 root root 4096 Dec 23 17:43 ./configs/def.2/bmAttributes
| 1003 0 -rw-r--r-- 1 root root 4096 Dec 23 17:43 ./configs/def.2/MaxPower
| 979 0 drwxr-xr-x 3 root root 0 Dec 23 17:42 ./configs/def.1
| 980 0 drwxr-xr-x 3 root root 0 Dec 23 17:42 ./configs/def.1/strings
| 5122 0 drwxr-xr-x 2 root root 0 Dec 23 17:42 ./configs/def.1/strings/0x409
| 1004 0 -rw-r--r-- 1 root root 4096 Dec 23 17:43 ./configs/def.1/strings/0x409/configuration
| 1005 0 -rw-r--r-- 1 root root 4096 Dec 23 17:43 ./configs/def.1/bmAttributes
| 1006 0 -rw-r--r-- 1 root root 4096 Dec 23 17:43 ./configs/def.1/MaxPower
| 976 0 drwxr-xr-x 3 root root 0 Dec 23 17:41 ./functions
| 981 0 drwxr-xr-x 2 root root 0 Dec 23 17:41 ./functions/acm.ttyS1
| 1007 0 -r--r--r-- 1 root root 4096 Dec 23 17:43 ./functions/acm.ttyS1/port_num
| 1008 0 -rw-r--r-- 1 root root 4096 Dec 23 17:43 ./UDC
| 1009 0 -rw-r--r-- 1 root root 4096 Dec 23 17:43 ./bcdUSB
| 1010 0 -rw-r--r-- 1 root root 4096 Dec 23 17:43 ./bcdDevice
| 1011 0 -rw-r--r-- 1 root root 4096 Dec 23 17:43 ./idProduct
| 1012 0 -rw-r--r-- 1 root root 4096 Dec 23 17:43 ./idVendor
| 1013 0 -rw-r--r-- 1 root root 4096 Dec 23 17:43 ./bMaxPacketSize0
| 1014 0 -rw-r--r-- 1 root root 4096 Dec 23 17:43 ./bDeviceProtocol
| 1015 0 -rw-r--r-- 1 root root 4096 Dec 23 17:43 ./bDeviceSubClass
| 1016 0 -rw-r--r-- 1 root root 4096 Dec 23 17:43 ./bDeviceClass

|# cat functions/acm.ttyS1/port_num
|0
|# ls -lah /dev/ttyGS*
|crw-rw---T 1 root dialout 252, 0 Dec 23 17:41 /dev/ttyGS0
|
|# echo 0x1234 > idProduct
|# echo 0xabcd > idVendor
|# echo 1122 > strings/0x409/serialnumber
|# echo "The manufacturer" > strings/0x409/manufacturer
|# echo 1 > strings/1032/manufacturer
|# echo 1sa > strings/1032/product
|# echo tada > strings/1032/serialnumber
|echo "Primary configuration" > configs/def.1/strings/0x409/configuration
|# echo "Secondary configuration" > configs/def.2/strings/0x409/configuration
|# ln -s functions/acm.ttyS1 configs/def.1/
|# ln -s functions/acm.ttyS1 configs/def.2/
|find configs/def.1/ -ls
| 979 0 drwxr-xr-x 3 root root 0 Dec 23 17:49 configs/def.1/
| 6264 0 lrwxrwxrwx 1 root root 0 Dec 23 17:48 configs/def.1/acm.ttyS1 -> ../../../../usb_gadget/oha/functions/acm.ttyS1
| 980 0 drwxr-xr-x 3 root root 0 Dec 23 17:42 configs/def.1/strings
| 5122 0 drwxr-xr-x 2 root root 0 Dec 23 17:49 configs/def.1/strings/0x409
| 6284 0 -rw-r--r-- 1 root root 4096 Dec 23 17:47 configs/def.1/strings/0x409/configuration
| 6285 0 -rw-r--r-- 1 root root 4096 Dec 23 17:49 configs/def.1/bmAttributes
| 6286 0 -rw-r--r-- 1 root root 4096 Dec 23 17:49 configs/def.1/MaxPower
|
|echo 120 > configs/def.1/MaxPower
|
|# ls -lh /sys/class/udc/
|total 0
|lrwxrwxrwx 1 root root 0 Dec 23 17:50 dummy_udc.0 -> ../../devices/platform/dummy_udc.0/udc/dummy_udc.0
|lrwxrwxrwx 1 root root 0 Dec 23 17:50 dummy_udc.1 -> ../../devices/platform/dummy_udc.1/udc/dummy_udc.1
|# echo dummy_udc.0 > UDC
|# lsusb
|Bus 001 Device 002: ID abcd:1234 Unknown
|
|lsusb -d abcd:1234 -v
|Device Descriptor:
…
| idVendor 0xabcd Unknown
| idProduct 0x1234
| bcdDevice 3.06
| iManufacturer 1 The manufacturer
| iProduct 2
| iSerial 3 1122
| bNumConfigurations 2
…
|echo "" > UDC

v5…v6
- wired up strings with usb_gstrings_attach()
- add UDC attribe. Write "udc-name" will bind the gadget. Write an empty
string (it should contain \n since 0 bytes write get optimzed away)
will unbind the UDC from the gadget. The name of available UDCs can be
obtained from /sys/class/udc/

v4…v5
- string rework. This will add a strings folder incl. language code like
strings/409/manufacturer
as suggested by Alan.
- rebased ontop reworked functions.c which has usb_function_instance
which is used prior after "mkdir acm.instance" and can be directly
used for configuration via configfs.

v3…v4
- moved functions from the root folde down to the gadget as suggested
by Michał
- configs have now their own configs folder as suggested by Michał.
The folder is still name.bConfigurationValue where name becomes the
sConfiguration. Is this usefull should we just stilc
configs/bConfigurationValue/ ?
- added configfs support to the ACM function. The port_num attribute is
exported by f_acm. An argument has been added to the USB alloc
function to distinguish between "old" (use facm_configure() to
configure and configfs interface (expose a config_node).
The port_num is currently a dumb counter. It will
require some function re-work to make it work.

scheduled for v5:
- sym linking function into config.

v2…v3
- replaced one ifndef by ifdef as suggested by Micahał
- strstr()/strchr() function_make as suggested by Micahł
- replace [iSerialNumber|iProduct|iManufacturer] with
[sSerialNumber|sProduct|sManufacturer] as suggested by Alan
- added creation of config descriptors

v1…v2
- moved gadgets from configfs' root directory into /udcs/ within our
"usb_gadget" folder. Requested by Andrzej & Michał
- use a dot as a delimiter between function's name and its instance's name
as suggested by Michał
- renamed all config_item_type, configfs_group_operations, make_group,
drop_item as suggested by suggested by Andrzej to remain consisten
within this file and within other configfs users
- Since configfs.c and functions.c are now part of the udc-core module,
the module itself is now called udc. Also added a tiny ifdef around
init code becuase udc-core is subsys init and this is too early for
configfs in the built-in case. In the module case, we can only have
one init function.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Felipe Balbi <balbi@ti.com>