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