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. --- lib/uuid.c | 134 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 134 insertions(+) create mode 100644 lib/uuid.c (limited to 'lib/uuid.c') diff --git a/lib/uuid.c b/lib/uuid.c new file mode 100644 index 000000000..128a51f18 --- /dev/null +++ b/lib/uuid.c @@ -0,0 +1,134 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Unified UUID/GUID definition + * + * Copyright (C) 2009, 2016 Intel Corp. + * Huang Ying + */ + +#include +#include +#include +#include +#include +#include +#include + +const guid_t guid_null; +EXPORT_SYMBOL(guid_null); +const uuid_t uuid_null; +EXPORT_SYMBOL(uuid_null); + +const u8 guid_index[16] = {3,2,1,0,5,4,7,6,8,9,10,11,12,13,14,15}; +const u8 uuid_index[16] = {0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15}; + +/** + * generate_random_uuid - generate a random UUID + * @uuid: where to put the generated UUID + * + * Random UUID interface + * + * Used to create a Boot ID or a filesystem UUID/GUID, but can be + * useful for other kernel drivers. + */ +void generate_random_uuid(unsigned char uuid[16]) +{ + get_random_bytes(uuid, 16); + /* Set UUID version to 4 --- truly random generation */ + uuid[6] = (uuid[6] & 0x0F) | 0x40; + /* Set the UUID variant to DCE */ + uuid[8] = (uuid[8] & 0x3F) | 0x80; +} +EXPORT_SYMBOL(generate_random_uuid); + +void generate_random_guid(unsigned char guid[16]) +{ + get_random_bytes(guid, 16); + /* Set GUID version to 4 --- truly random generation */ + guid[7] = (guid[7] & 0x0F) | 0x40; + /* Set the GUID variant to DCE */ + guid[8] = (guid[8] & 0x3F) | 0x80; +} +EXPORT_SYMBOL(generate_random_guid); + +static void __uuid_gen_common(__u8 b[16]) +{ + get_random_bytes(b, 16); + /* revision 0b10 */ + b[8] = (b[8] & 0x3F) | 0x80; +} + +void guid_gen(guid_t *lu) +{ + __uuid_gen_common(lu->b); + /* version 4 : random generation */ + lu->b[7] = (lu->b[7] & 0x0F) | 0x40; +} +EXPORT_SYMBOL_GPL(guid_gen); + +void uuid_gen(uuid_t *bu) +{ + __uuid_gen_common(bu->b); + /* version 4 : random generation */ + bu->b[6] = (bu->b[6] & 0x0F) | 0x40; +} +EXPORT_SYMBOL_GPL(uuid_gen); + +/** + * uuid_is_valid - checks if a UUID string is valid + * @uuid: UUID string to check + * + * Description: + * It checks if the UUID string is following the format: + * xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx + * + * where x is a hex digit. + * + * Return: true if input is valid UUID string. + */ +bool uuid_is_valid(const char *uuid) +{ + unsigned int i; + + for (i = 0; i < UUID_STRING_LEN; i++) { + if (i == 8 || i == 13 || i == 18 || i == 23) { + if (uuid[i] != '-') + return false; + } else if (!isxdigit(uuid[i])) { + return false; + } + } + + return true; +} +EXPORT_SYMBOL(uuid_is_valid); + +static int __uuid_parse(const char *uuid, __u8 b[16], const u8 ei[16]) +{ + static const u8 si[16] = {0,2,4,6,9,11,14,16,19,21,24,26,28,30,32,34}; + unsigned int i; + + if (!uuid_is_valid(uuid)) + return -EINVAL; + + for (i = 0; i < 16; i++) { + int hi = hex_to_bin(uuid[si[i] + 0]); + int lo = hex_to_bin(uuid[si[i] + 1]); + + b[ei[i]] = (hi << 4) | lo; + } + + return 0; +} + +int guid_parse(const char *uuid, guid_t *u) +{ + return __uuid_parse(uuid, u->b, guid_index); +} +EXPORT_SYMBOL(guid_parse); + +int uuid_parse(const char *uuid, uuid_t *u) +{ + return __uuid_parse(uuid, u->b, uuid_index); +} +EXPORT_SYMBOL(uuid_parse); -- cgit v1.3.1