From 9cc63f8bcd560c760d0b12e15bba8f81c86237cf Mon Sep 17 00:00:00 2001 From: "Paul E. McKenney" Date: Fri, 14 Aug 2026 15:43:51 -0700 Subject: Merge branches 'expcb.2026.07.24a', 'misc.2026.07.30a', 'rcu-tasks.2026.07.30a', 'srcu.2026.08.11a' and 'torture.2026.08.14a' into HEAD Changes: Make expedited grace periods expedite normal RCU callbacks Miscellaneous fixes: * Improve diagnostic output with character task states. * Mark accesses to inform KCSAN of concurrency design. * Move from kmalloc() to kmalloc_obj(). * Documentation updates. * Improve handling of RCU deferred quiescent states. * Clean up unused function arguments and structure fields. * Reduce show_rcu_gp_kthreads() stack space. Tasks RCU updates: * Clean up after SRCU re-implementation of Tasks Trace RCU. * Mark accesses to inform KCSAN of concurrency design. * Add ->lazy_timer status to diagnostic output. * Remove an unnecessary memory barrier. * Fix a data race, courtesy of KCSAN. * Documentation updates. * Convert cond_resched_tasks_rcu_qs() from macro to static inline function. SRCU updates: * Add Rust helpers for SRCU. * Avoid losing queued work at cleanup_srcu_struct() time. Torture-test updates: * Preparation work for immediate RCU priority deboosting. * Test RCU readers from real interrupt handlers (as opposed to softirq). * Simplify code through use of cpumask_next_wrap(). * Improve diagnostic output with character task states. * Add rcutorture.nwriters parameter to allow lightweight stall testing, and rcutorture.stall_only to make doing so easier. * Test an RCU Tasks Trace grace period implying an RCU grace period. * Make RCU Tasks Trace torturing track reader batches. * Fix a data race, courtesy of KCSAN. * Plug a shuffle_tmp_mask memory leak on kthread spawn failure. --- drivers/usb/gadget/usbstring.c | 91 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 91 insertions(+) create mode 100644 drivers/usb/gadget/usbstring.c (limited to 'drivers/usb/gadget/usbstring.c') diff --git a/drivers/usb/gadget/usbstring.c b/drivers/usb/gadget/usbstring.c new file mode 100644 index 000000000..37a2f1b61 --- /dev/null +++ b/drivers/usb/gadget/usbstring.c @@ -0,0 +1,91 @@ +// SPDX-License-Identifier: LGPL-2.1+ +/* + * Copyright (C) 2003 David Brownell + */ + +#include +#include +#include +#include +#include +#include +#include + +#include +#include + + +/** + * usb_gadget_get_string - fill out a string descriptor + * @table: of c strings encoded using UTF-8 + * @id: string id, from low byte of wValue in get string descriptor + * @buf: at least 256 bytes, must be 16-bit aligned + * + * Finds the UTF-8 string matching the ID, and converts it into a + * string descriptor in utf16-le. + * Returns length of descriptor (always even) or negative errno + * + * If your driver needs stings in multiple languages, you'll probably + * "switch (wIndex) { ... }" in your ep0 string descriptor logic, + * using this routine after choosing which set of UTF-8 strings to use. + * Note that US-ASCII is a strict subset of UTF-8; any string bytes with + * the eighth bit set will be multibyte UTF-8 characters, not ISO-8859/1 + * characters (which are also widely used in C strings). + */ +int +usb_gadget_get_string (const struct usb_gadget_strings *table, int id, u8 *buf) +{ + struct usb_string *s; + int len; + + /* descriptor 0 has the language id */ + if (id == 0) { + buf [0] = 4; + buf [1] = USB_DT_STRING; + buf [2] = (u8) table->language; + buf [3] = (u8) (table->language >> 8); + return 4; + } + for (s = table->strings; s && s->s; s++) + if (s->id == id) + break; + + /* unrecognized: stall. */ + if (!s || !s->s) + return -EINVAL; + + /* string descriptors have length, tag, then UTF16-LE text */ + len = min_t(size_t, USB_MAX_STRING_LEN, strlen(s->s)); + len = utf8s_to_utf16s(s->s, len, UTF16_LITTLE_ENDIAN, + (wchar_t *) &buf[2], USB_MAX_STRING_LEN); + if (len < 0) + return -EINVAL; + buf [0] = (len + 1) * 2; + buf [1] = USB_DT_STRING; + return buf [0]; +} +EXPORT_SYMBOL_GPL(usb_gadget_get_string); + +/** + * usb_validate_langid - validate usb language identifiers + * @langid: usb language identifier + * + * Returns true for valid language identifier, otherwise false. + */ +bool usb_validate_langid(u16 langid) +{ + u16 primary_lang = langid & 0x3ff; /* bit [9:0] */ + u16 sub_lang = langid >> 10; /* bit [15:10] */ + + switch (primary_lang) { + case 0: + case 0x62 ... 0xfe: + case 0x100 ... 0x3ff: + return false; + } + if (!sub_lang) + return false; + + return true; +} +EXPORT_SYMBOL_GPL(usb_validate_langid); -- cgit v1.3.1