1// SPDX-License-Identifier: GPL-2.0 2/* 3 * Non-trivial C macros cannot be used in Rust. Similarly, inlined C functions 4 * cannot be called either. This file explicitly creates functions ("helpers") 5 * that wrap those so that they can be called from Rust. 6 * 7 * Even though Rust kernel modules should never use the bindings directly, some 8 * of these helpers need to be exported because Rust generics and inlined 9 * functions may not get their code generated in the crate where they are 10 * defined. Other helpers, called from non-inline functions, may not be 11 * exported, in principle. However, in general, the Rust compiler does not 12 * guarantee codegen will be performed for a non-inline function either. 13 * Therefore, this file exports all the helpers. In the future, this may be 14 * revisited to reduce the number of exports after the compiler is informed 15 * about the places codegen is required. 16 * 17 * All symbols are exported as GPL-only to guarantee no GPL-only feature is 18 * accidentally exposed. 19 * 20 * Sorted alphabetically. 21 */ 22 23#include <kunit/test-bug.h> 24#include <linux/bug.h> 25#include <linux/build_bug.h> 26#include <linux/err.h> 27#include <linux/errname.h> 28#include <linux/mutex.h> 29#include <linux/refcount.h> 30#include <linux/sched/signal.h> 31#include <linux/slab.h> 32#include <linux/spinlock.h> 33#include <linux/wait.h> 34#include <linux/workqueue.h> 35 36__noreturn void rust_helper_BUG(void) 37{ 38 BUG(); 39} 40EXPORT_SYMBOL_GPL(rust_helper_BUG); 41 42void rust_helper_mutex_lock(struct mutex *lock) 43{ 44 mutex_lock(lock); 45} 46EXPORT_SYMBOL_GPL(rust_helper_mutex_lock); 47 48void rust_helper___spin_lock_init(spinlock_t *lock, const char *name, 49 struct lock_class_key *key) 50{ 51#ifdef CONFIG_DEBUG_SPINLOCK 52 __raw_spin_lock_init(spinlock_check(lock), name, key, LD_WAIT_CONFIG); 53#else 54 spin_lock_init(lock); 55#endif 56} 57EXPORT_SYMBOL_GPL(rust_helper___spin_lock_init); 58 59void rust_helper_spin_lock(spinlock_t *lock) 60{ 61 spin_lock(lock); 62} 63EXPORT_SYMBOL_GPL(rust_helper_spin_lock); 64 65void rust_helper_spin_unlock(spinlock_t *lock) 66{ 67 spin_unlock(lock); 68} 69EXPORT_SYMBOL_GPL(rust_helper_spin_unlock); 70 71void rust_helper_init_wait(struct wait_queue_entry *wq_entry) 72{ 73 init_wait(wq_entry); 74} 75EXPORT_SYMBOL_GPL(rust_helper_init_wait); 76 77int rust_helper_signal_pending(struct task_struct *t) 78{ 79 return signal_pending(t); 80} 81EXPORT_SYMBOL_GPL(rust_helper_signal_pending); 82 83refcount_t rust_helper_REFCOUNT_INIT(int n) 84{ 85 return (refcount_t)REFCOUNT_INIT(n); 86} 87EXPORT_SYMBOL_GPL(rust_helper_REFCOUNT_INIT); 88 89void rust_helper_refcount_inc(refcount_t *r) 90{ 91 refcount_inc(r); 92} 93EXPORT_SYMBOL_GPL(rust_helper_refcount_inc); 94 95bool rust_helper_refcount_dec_and_test(refcount_t *r) 96{ 97 return refcount_dec_and_test(r); 98} 99EXPORT_SYMBOL_GPL(rust_helper_refcount_dec_and_test); 100 101__force void *rust_helper_ERR_PTR(long err) 102{ 103 return ERR_PTR(err); 104} 105EXPORT_SYMBOL_GPL(rust_helper_ERR_PTR); 106 107bool rust_helper_IS_ERR(__force const void *ptr) 108{ 109 return IS_ERR(ptr); 110} 111EXPORT_SYMBOL_GPL(rust_helper_IS_ERR); 112 113long rust_helper_PTR_ERR(__force const void *ptr) 114{ 115 return PTR_ERR(ptr); 116} 117EXPORT_SYMBOL_GPL(rust_helper_PTR_ERR); 118 119const char *rust_helper_errname(int err) 120{ 121 return errname(err); 122} 123EXPORT_SYMBOL_GPL(rust_helper_errname); 124 125struct task_struct *rust_helper_get_current(void) 126{ 127 return current; 128} 129EXPORT_SYMBOL_GPL(rust_helper_get_current); 130 131void rust_helper_get_task_struct(struct task_struct *t) 132{ 133 get_task_struct(t); 134} 135EXPORT_SYMBOL_GPL(rust_helper_get_task_struct); 136 137void rust_helper_put_task_struct(struct task_struct *t) 138{ 139 put_task_struct(t); 140} 141EXPORT_SYMBOL_GPL(rust_helper_put_task_struct); 142 143struct kunit *rust_helper_kunit_get_current_test(void) 144{ 145 return kunit_get_current_test(); 146} 147EXPORT_SYMBOL_GPL(rust_helper_kunit_get_current_test); 148 149void rust_helper_init_work_with_key(struct work_struct *work, work_func_t func, 150 bool onstack, const char *name, 151 struct lock_class_key *key) 152{ 153 __init_work(work, onstack); 154 work->data = (atomic_long_t)WORK_DATA_INIT(); 155 lockdep_init_map(&work->lockdep_map, name, key, 0); 156 INIT_LIST_HEAD(&work->entry); 157 work->func = func; 158} 159EXPORT_SYMBOL_GPL(rust_helper_init_work_with_key); 160 161void * __must_check __realloc_size(2) 162rust_helper_krealloc(const void *objp, size_t new_size, gfp_t flags) 163{ 164 return krealloc(objp, new_size, flags); 165} 166EXPORT_SYMBOL_GPL(rust_helper_krealloc); 167 168/* 169 * `bindgen` binds the C `size_t` type as the Rust `usize` type, so we can 170 * use it in contexts where Rust expects a `usize` like slice (array) indices. 171 * `usize` is defined to be the same as C's `uintptr_t` type (can hold any 172 * pointer) but not necessarily the same as `size_t` (can hold the size of any 173 * single object). Most modern platforms use the same concrete integer type for 174 * both of them, but in case we find ourselves on a platform where 175 * that's not true, fail early instead of risking ABI or 176 * integer-overflow issues. 177 * 178 * If your platform fails this assertion, it means that you are in 179 * danger of integer-overflow bugs (even if you attempt to add 180 * `--no-size_t-is-usize`). It may be easiest to change the kernel ABI on 181 * your platform such that `size_t` matches `uintptr_t` (i.e., to increase 182 * `size_t`, because `uintptr_t` has to be at least as big as `size_t`). 183 */ 184static_assert( 185 sizeof(size_t) == sizeof(uintptr_t) && 186 __alignof__(size_t) == __alignof__(uintptr_t), 187 "Rust code expects C `size_t` to match Rust `usize`" 188); 189