kernel/linux.git/drivers/usb/gadget/function/f_uac2.c, branch linux-7.0.y

Convert 'alloc_obj' family to use the new default GFP_KERNEL argument

2026-02-22T01:09:51+00:00

This was done entirely with mindless brute force, using git grep -l '\

treewide: Replace kmalloc with kmalloc_obj for non-scalar types

2026-02-21T09:02:28+00:00

This is the result of running the Coccinelle script from scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to avoid scalar types (which need careful case-by-case checking), and instead replace kmalloc-family calls that allocate struct or union object instances: Single allocations: kmalloc(sizeof(TYPE), ...) are replaced with: kmalloc_obj(TYPE, ...) Array allocations: kmalloc_array(COUNT, sizeof(TYPE), ...) are replaced with: kmalloc_objs(TYPE, COUNT, ...) Flex array allocations: kmalloc(struct_size(PTR, FAM, COUNT), ...) are replaced with: kmalloc_flex(*PTR, FAM, COUNT, ...) (where TYPE may also be *VAR) The resulting allocations no longer return "void *", instead returning "TYPE *". Signed-off-by: Kees Cook

usb: gadget: Constify struct configfs_item_operations and configfs_group_operations

2025-12-23T14:31:01+00:00

'struct configfs_item_operations' and 'configfs_group_operations' are not modified in these drivers. Constifying these structures moves some data to a read-only section, so increases overall security, especially when the structure holds some function pointers. On a x86_64, with allmodconfig, as an example: Before: ====== text data bss dec hex filename 65061 20968 256 86285 1510d drivers/usb/gadget/configfs.o After: ===== text data bss dec hex filename 66181 19848 256 86285 1510d drivers/usb/gadget/configfs.o Signed-off-by: Christophe JAILLET Link: https://patch.msgid.link/49cec1cb84425f854de80b6d69b53a5a3cda8189.1766164523.git.christophe.jaillet@wanadoo.fr Signed-off-by: Greg Kroah-Hartman

usb: gadget: f_uac2: replace scnprintf() with sysfs_emit()

2025-07-07T09:05:30+00:00

Documentation/filesystems/sysfs.rst mentions that show() should only use sysfs_emit() or sysfs_emit_at() when formating the value to be returned to user space. So replace scnprintf() with sysfs_emit(). Signed-off-by: Sumanth Gavini Link: https://lore.kernel.org/r/20250704003425.467299-1-sumanth.gavini@yahoo.com Signed-off-by: Greg Kroah-Hartman

usb: gadget: f_uac2: Fix incorrect setting of bNumEndpoints

2024-12-23T17:50:28+00:00

Currently afunc_bind sets std_ac_if_desc.bNumEndpoints to 1 if controls (mute/volume) are enabled. During next afunc_bind call, bNumEndpoints would be unchanged and incorrectly set to 1 even if the controls aren't enabled. Fix this by resetting the value of bNumEndpoints to 0 on every afunc_bind call. Fixes: eaf6cbe09920 ("usb: gadget: f_uac2: add volume and mute support") Cc: stable Signed-off-by: Prashanth K Link: https://lore.kernel.org/r/20241211115915.159864-1-quic_prashk@quicinc.com Signed-off-by: Greg Kroah-Hartman

usb: gadget: f_uac2: fix return value for UAC2_ATTRIBUTE_STRING store

2024-10-16T08:28:28+00:00

The configfs store callback should return the number of bytes consumed not the total number of bytes we actually stored. These could differ if for example the passed in string had a newline we did not store. If the returned value does not match the number of bytes written the writer might assume a failure or keep trying to write the remaining bytes. For example the following command will hang trying to write the final newline over and over again (tested on bash 2.05b): echo foo > function_name Fixes: 993a44fa85c1 ("usb: gadget: f_uac2: allow changing interface name via configfs") Cc: stable Signed-off-by: Kevin Groeneveld Link: https://lore.kernel.org/r/20241006232637.4267-1-kgroeneveld@lenbrook.com Signed-off-by: Greg Kroah-Hartman

usb: gadget: f_uac2: Expose all string descriptors through configfs.

2024-08-13T08:37:05+00:00

This makes all string descriptors configurable for the UAC2 gadget so the user can configure names of terminals and controls. Alt mode names are not included for now and will be in future work related to adding alternate settings. discussion thread for api changes for alt mode settings: https://lore.kernel.org/linux-usb/35be4668-58d3-894a-72cf-de1afaacae45@ivitera.com/T/ Signed-off-by: Chris Wulff Link: https://lore.kernel.org/r/20240804001923.3279431-2-crwulff@gmail.com Signed-off-by: Greg Kroah-Hartman

usb: gadget: f_uac2: fix non-newline-terminated function name

2024-07-10T13:40:26+00:00

Most writes to configfs handle an optional newline, but do not require it. By using the number of bytes written as the limit for scnprintf() it is guaranteed that the final character in the buffer will be overwritten. This is expected if it is a newline but is undesirable when a string is written "as-is" (as libusbgx does, for example). Update the store function to strip an optional newline, matching the behaviour of usb_string_copy(). Signed-off-by: John Keeping Link: https://lore.kernel.org/r/20240708142553.3995022-1-jkeeping@inmusicbrands.com Signed-off-by: Greg Kroah-Hartman

usb: gadget: add missing MODULE_DESCRIPTION() macros

2024-06-20T17:18:19+00:00

make allmodconfig && make W=1 C=1 reports: WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/usb/gadget/libcomposite.o WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/usb/gadget/function/usb_f_acm.o WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/usb/gadget/function/usb_f_ss_lb.o WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/usb/gadget/function/u_serial.o WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/usb/gadget/function/usb_f_serial.o WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/usb/gadget/function/usb_f_obex.o WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/usb/gadget/function/u_ether.o WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/usb/gadget/function/usb_f_ncm.o WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/usb/gadget/function/usb_f_ecm.o WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/usb/gadget/function/usb_f_phonet.o WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/usb/gadget/function/usb_f_eem.o WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/usb/gadget/function/usb_f_ecm_subset.o WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/usb/gadget/function/usb_f_rndis.o WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/usb/gadget/function/usb_f_mass_storage.o WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/usb/gadget/function/usb_f_fs.o WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/usb/gadget/function/usb_f_uac1.o WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/usb/gadget/function/usb_f_uac1_legacy.o WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/usb/gadget/function/usb_f_uac2.o WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/usb/gadget/function/usb_f_uvc.o WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/usb/gadget/function/usb_f_midi.o WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/usb/gadget/function/usb_f_midi2.o WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/usb/gadget/function/usb_f_hid.o WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/usb/gadget/function/usb_f_printer.o WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/usb/gadget/function/usb_f_tcm.o WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/usb/gadget/legacy/g_zero.o WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/usb/gadget/legacy/g_midi.o WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/usb/gadget/legacy/g_dbgp.o Add the missing invocations of the MODULE_DESCRIPTION() macro. Signed-off-by: Jeff Johnson Link: https://lore.kernel.org/r/20240605-md-drivers-usb-gadget-v1-1-29847a46aad3@quicinc.com Signed-off-by: Greg Kroah-Hartman

usb: gadget: f_uac2: Replace snprintf() with the safer scnprintf() variant

2023-12-15T12:55:29+00:00

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 Cc: James Gruber Cc: Yadwinder Singh Cc: Jaswinder Singh Cc: Ruslan Bilovol Signed-off-by: Lee Jones Link: https://lore.kernel.org/r/20231213164246.1021885-4-lee@kernel.org Signed-off-by: Greg Kroah-Hartman