usb: gadget: function: move u_f.h to include/linux/usb/func_utils.h

We move the func_utils.h header to include/linux/usb to be
able to compile function drivers outside of the
drivers/usb/gadget/func

usb: gadget: function: move u_f.h to include/linux/usb/func_utils.h

We move the func_utils.h header to include/linux/usb to be
able to compile function drivers outside of the
drivers/usb/gadget/function directory.

Signed-off-by: Michael Grzeschik <m.grzeschik@pengutronix.de>
Link: https://lore.kernel.org/r/20240116-ml-topic-u9p-v12-1-9a27de5160e0@pengutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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usb: gadget: configfs: Constify struct config_item_type

'struct config_item_type' is not modified in this file.

Apparently, these structures are only used with
config_group_init_type_name() which t

usb: gadget: configfs: Constify struct config_item_type

'struct config_item_type' is not modified in this file.

Apparently, these structures are only used with
config_group_init_type_name() which takes a const struct config_item_type*
as a 3rd argument.

Constifying this structure moves some data to a read-only section, so
increase overall security, especially when the structure holds some
function pointers.

On a x86_64, with allmodconfig:
Before:
======
text data bss dec hex filename
40834 5112 64 46010 b3ba drivers/usb/gadget/configfs.o

After:
=====
text data bss dec hex filename
41218 4728 64 46010 b3ba drivers/usb/gadget/configfs.o

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Link: https://lore.kernel.org/r/513223e97082e1bb758e36d55c175ec9ea34a71c.1723323896.git.christophe.jaillet@wanadoo.fr
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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usb: gadget: configfs: Make check_user_usb_string() static

"linux/usb/gadget_configfs.h" is only included in
"drivers/usb/gadget/configfs.c", so there is no need to declare a function
in the header

usb: gadget: configfs: Make check_user_usb_string() static

"linux/usb/gadget_configfs.h" is only included in
"drivers/usb/gadget/configfs.c", so there is no need to declare a function
in the header file. it is only used in this .c file.

It's better to have it static.

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Link: https://lore.kernel.org/r/958cb49dca1bff4254a3492c018efbf3b01918b4.1723323107.git.christophe.jaillet@wanadoo.fr
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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usb: gadget: configfs: Prevent OOB read/write in usb_string_copy()

Userspace provided string 's' could trivially have the length zero. Left
unchecked this will firstly result in an OOB read in the f

usb: gadget: configfs: Prevent OOB read/write in usb_string_copy()

Userspace provided string 's' could trivially have the length zero. Left
unchecked this will firstly result in an OOB read in the form
`if (str[0 - 1] == '\n') followed closely by an OOB write in the form
`str[0 - 1] = '\0'`.

There is already a validating check to catch strings that are too long.
Let's supply an additional check for invalid strings that are too short.

Signed-off-by: Lee Jones <lee@kernel.org>
Cc: stable <stable@kernel.org>
Link: https://lore.kernel.org/r/20240705074339.633717-1-lee@kernel.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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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* encode

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>

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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

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>

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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 t

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>

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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

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>

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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

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>

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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 rath

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>

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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.s

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>

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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 f

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>

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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

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>

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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 Shevche

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>

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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 Keepin

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>

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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 Co

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>

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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
prin

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>

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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 simplif

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>

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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 accur

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>

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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 enable

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>

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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 st

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>

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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>

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>

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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: Li

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>

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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 'dumm

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>

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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,
with

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>

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