Linux kernel mirror (for testing)
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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 directly the bindings, 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/spinlock.h>
32#include <linux/wait.h>
33#include <linux/workqueue.h>
34
35__noreturn void rust_helper_BUG(void)
36{
37 BUG();
38}
39EXPORT_SYMBOL_GPL(rust_helper_BUG);
40
41void rust_helper_mutex_lock(struct mutex *lock)
42{
43 mutex_lock(lock);
44}
45EXPORT_SYMBOL_GPL(rust_helper_mutex_lock);
46
47void rust_helper___spin_lock_init(spinlock_t *lock, const char *name,
48 struct lock_class_key *key)
49{
50#ifdef CONFIG_DEBUG_SPINLOCK
51 __raw_spin_lock_init(spinlock_check(lock), name, key, LD_WAIT_CONFIG);
52#else
53 spin_lock_init(lock);
54#endif
55}
56EXPORT_SYMBOL_GPL(rust_helper___spin_lock_init);
57
58void rust_helper_spin_lock(spinlock_t *lock)
59{
60 spin_lock(lock);
61}
62EXPORT_SYMBOL_GPL(rust_helper_spin_lock);
63
64void rust_helper_spin_unlock(spinlock_t *lock)
65{
66 spin_unlock(lock);
67}
68EXPORT_SYMBOL_GPL(rust_helper_spin_unlock);
69
70void rust_helper_init_wait(struct wait_queue_entry *wq_entry)
71{
72 init_wait(wq_entry);
73}
74EXPORT_SYMBOL_GPL(rust_helper_init_wait);
75
76int rust_helper_signal_pending(struct task_struct *t)
77{
78 return signal_pending(t);
79}
80EXPORT_SYMBOL_GPL(rust_helper_signal_pending);
81
82refcount_t rust_helper_REFCOUNT_INIT(int n)
83{
84 return (refcount_t)REFCOUNT_INIT(n);
85}
86EXPORT_SYMBOL_GPL(rust_helper_REFCOUNT_INIT);
87
88void rust_helper_refcount_inc(refcount_t *r)
89{
90 refcount_inc(r);
91}
92EXPORT_SYMBOL_GPL(rust_helper_refcount_inc);
93
94bool rust_helper_refcount_dec_and_test(refcount_t *r)
95{
96 return refcount_dec_and_test(r);
97}
98EXPORT_SYMBOL_GPL(rust_helper_refcount_dec_and_test);
99
100__force void *rust_helper_ERR_PTR(long err)
101{
102 return ERR_PTR(err);
103}
104EXPORT_SYMBOL_GPL(rust_helper_ERR_PTR);
105
106bool rust_helper_IS_ERR(__force const void *ptr)
107{
108 return IS_ERR(ptr);
109}
110EXPORT_SYMBOL_GPL(rust_helper_IS_ERR);
111
112long rust_helper_PTR_ERR(__force const void *ptr)
113{
114 return PTR_ERR(ptr);
115}
116EXPORT_SYMBOL_GPL(rust_helper_PTR_ERR);
117
118const char *rust_helper_errname(int err)
119{
120 return errname(err);
121}
122EXPORT_SYMBOL_GPL(rust_helper_errname);
123
124struct task_struct *rust_helper_get_current(void)
125{
126 return current;
127}
128EXPORT_SYMBOL_GPL(rust_helper_get_current);
129
130void rust_helper_get_task_struct(struct task_struct *t)
131{
132 get_task_struct(t);
133}
134EXPORT_SYMBOL_GPL(rust_helper_get_task_struct);
135
136void rust_helper_put_task_struct(struct task_struct *t)
137{
138 put_task_struct(t);
139}
140EXPORT_SYMBOL_GPL(rust_helper_put_task_struct);
141
142struct kunit *rust_helper_kunit_get_current_test(void)
143{
144 return kunit_get_current_test();
145}
146EXPORT_SYMBOL_GPL(rust_helper_kunit_get_current_test);
147
148void rust_helper_init_work_with_key(struct work_struct *work, work_func_t func,
149 bool onstack, const char *name,
150 struct lock_class_key *key)
151{
152 __init_work(work, onstack);
153 work->data = (atomic_long_t)WORK_DATA_INIT();
154 lockdep_init_map(&work->lockdep_map, name, key, 0);
155 INIT_LIST_HEAD(&work->entry);
156 work->func = func;
157}
158EXPORT_SYMBOL_GPL(rust_helper_init_work_with_key);
159
160/*
161 * `bindgen` binds the C `size_t` type as the Rust `usize` type, so we can
162 * use it in contexts where Rust expects a `usize` like slice (array) indices.
163 * `usize` is defined to be the same as C's `uintptr_t` type (can hold any
164 * pointer) but not necessarily the same as `size_t` (can hold the size of any
165 * single object). Most modern platforms use the same concrete integer type for
166 * both of them, but in case we find ourselves on a platform where
167 * that's not true, fail early instead of risking ABI or
168 * integer-overflow issues.
169 *
170 * If your platform fails this assertion, it means that you are in
171 * danger of integer-overflow bugs (even if you attempt to add
172 * `--no-size_t-is-usize`). It may be easiest to change the kernel ABI on
173 * your platform such that `size_t` matches `uintptr_t` (i.e., to increase
174 * `size_t`, because `uintptr_t` has to be at least as big as `size_t`).
175 */
176static_assert(
177 sizeof(size_t) == sizeof(uintptr_t) &&
178 __alignof__(size_t) == __alignof__(uintptr_t),
179 "Rust code expects C `size_t` to match Rust `usize`"
180);