summaryrefslogtreecommitdiff
path: root/rust/helpers.c
blob: 70e59efd92bc43784c2f0711e671f6463d0031e1 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
// SPDX-License-Identifier: GPL-2.0
/*
 * Non-trivial C macros cannot be used in Rust. Similarly, inlined C functions
 * cannot be called either. This file explicitly creates functions ("helpers")
 * that wrap those so that they can be called from Rust.
 *
 * Even though Rust kernel modules should never use directly the bindings, some
 * of these helpers need to be exported because Rust generics and inlined
 * functions may not get their code generated in the crate where they are
 * defined. Other helpers, called from non-inline functions, may not be
 * exported, in principle. However, in general, the Rust compiler does not
 * guarantee codegen will be performed for a non-inline function either.
 * Therefore, this file exports all the helpers. In the future, this may be
 * revisited to reduce the number of exports after the compiler is informed
 * about the places codegen is required.
 *
 * All symbols are exported as GPL-only to guarantee no GPL-only feature is
 * accidentally exposed.
 *
 * Sorted alphabetically.
 */

#include <kunit/test-bug.h>
#include <linux/bug.h>
#include <linux/build_bug.h>
#include <linux/err.h>
#include <linux/errname.h>
#include <linux/mutex.h>
#include <linux/refcount.h>
#include <linux/sched/signal.h>
#include <linux/spinlock.h>
#include <linux/wait.h>
#include <linux/workqueue.h>

__noreturn void rust_helper_BUG(void)
{
	BUG();
}
EXPORT_SYMBOL_GPL(rust_helper_BUG);

void rust_helper_mutex_lock(struct mutex *lock)
{
	mutex_lock(lock);
}
EXPORT_SYMBOL_GPL(rust_helper_mutex_lock);

void rust_helper___spin_lock_init(spinlock_t *lock, const char *name,
				  struct lock_class_key *key)
{
#ifdef CONFIG_DEBUG_SPINLOCK
	__raw_spin_lock_init(spinlock_check(lock), name, key, LD_WAIT_CONFIG);
#else
	spin_lock_init(lock);
#endif
}
EXPORT_SYMBOL_GPL(rust_helper___spin_lock_init);

void rust_helper_spin_lock(spinlock_t *lock)
{
	spin_lock(lock);
}
EXPORT_SYMBOL_GPL(rust_helper_spin_lock);

void rust_helper_spin_unlock(spinlock_t *lock)
{
	spin_unlock(lock);
}
EXPORT_SYMBOL_GPL(rust_helper_spin_unlock);

void rust_helper_init_wait(struct wait_queue_entry *wq_entry)
{
	init_wait(wq_entry);
}
EXPORT_SYMBOL_GPL(rust_helper_init_wait);

int rust_helper_signal_pending(struct task_struct *t)
{
	return signal_pending(t);
}
EXPORT_SYMBOL_GPL(rust_helper_signal_pending);

refcount_t rust_helper_REFCOUNT_INIT(int n)
{
	return (refcount_t)REFCOUNT_INIT(n);
}
EXPORT_SYMBOL_GPL(rust_helper_REFCOUNT_INIT);

void rust_helper_refcount_inc(refcount_t *r)
{
	refcount_inc(r);
}
EXPORT_SYMBOL_GPL(rust_helper_refcount_inc);

bool rust_helper_refcount_dec_and_test(refcount_t *r)
{
	return refcount_dec_and_test(r);
}
EXPORT_SYMBOL_GPL(rust_helper_refcount_dec_and_test);

__force void *rust_helper_ERR_PTR(long err)
{
	return ERR_PTR(err);
}
EXPORT_SYMBOL_GPL(rust_helper_ERR_PTR);

bool rust_helper_IS_ERR(__force const void *ptr)
{
	return IS_ERR(ptr);
}
EXPORT_SYMBOL_GPL(rust_helper_IS_ERR);

long rust_helper_PTR_ERR(__force const void *ptr)
{
	return PTR_ERR(ptr);
}
EXPORT_SYMBOL_GPL(rust_helper_PTR_ERR);

const char *rust_helper_errname(int err)
{
	return errname(err);
}
EXPORT_SYMBOL_GPL(rust_helper_errname);

struct task_struct *rust_helper_get_current(void)
{
	return current;
}
EXPORT_SYMBOL_GPL(rust_helper_get_current);

void rust_helper_get_task_struct(struct task_struct *t)
{
	get_task_struct(t);
}
EXPORT_SYMBOL_GPL(rust_helper_get_task_struct);

void rust_helper_put_task_struct(struct task_struct *t)
{
	put_task_struct(t);
}
EXPORT_SYMBOL_GPL(rust_helper_put_task_struct);

struct kunit *rust_helper_kunit_get_current_test(void)
{
	return kunit_get_current_test();
}
EXPORT_SYMBOL_GPL(rust_helper_kunit_get_current_test);

void rust_helper_init_work_with_key(struct work_struct *work, work_func_t func,
				    bool onstack, const char *name,
				    struct lock_class_key *key)
{
	__init_work(work, onstack);
	work->data = (atomic_long_t)WORK_DATA_INIT();
	lockdep_init_map(&work->lockdep_map, name, key, 0);
	INIT_LIST_HEAD(&work->entry);
	work->func = func;
}
EXPORT_SYMBOL_GPL(rust_helper_init_work_with_key);

/*
 * `bindgen` binds the C `size_t` type as the Rust `usize` type, so we can
 * use it in contexts where Rust expects a `usize` like slice (array) indices.
 * `usize` is defined to be the same as C's `uintptr_t` type (can hold any
 * pointer) but not necessarily the same as `size_t` (can hold the size of any
 * single object). Most modern platforms use the same concrete integer type for
 * both of them, but in case we find ourselves on a platform where
 * that's not true, fail early instead of risking ABI or
 * integer-overflow issues.
 *
 * If your platform fails this assertion, it means that you are in
 * danger of integer-overflow bugs (even if you attempt to add
 * `--no-size_t-is-usize`). It may be easiest to change the kernel ABI on
 * your platform such that `size_t` matches `uintptr_t` (i.e., to increase
 * `size_t`, because `uintptr_t` has to be at least as big as `size_t`).
 */
static_assert(
	sizeof(size_t) == sizeof(uintptr_t) &&
	__alignof__(size_t) == __alignof__(uintptr_t),
	"Rust code expects C `size_t` to match Rust `usize`"
);