Linux kernel mirror (for testing)
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linux
1#ifndef _LINUX_MMAP_LOCK_H
2#define _LINUX_MMAP_LOCK_H
3
4#include <linux/lockdep.h>
5#include <linux/mm_types.h>
6#include <linux/mmdebug.h>
7#include <linux/rwsem.h>
8#include <linux/tracepoint-defs.h>
9#include <linux/types.h>
10
11#define MMAP_LOCK_INITIALIZER(name) \
12 .mmap_lock = __RWSEM_INITIALIZER((name).mmap_lock),
13
14DECLARE_TRACEPOINT(mmap_lock_start_locking);
15DECLARE_TRACEPOINT(mmap_lock_acquire_returned);
16DECLARE_TRACEPOINT(mmap_lock_released);
17
18#ifdef CONFIG_TRACING
19
20void __mmap_lock_do_trace_start_locking(struct mm_struct *mm, bool write);
21void __mmap_lock_do_trace_acquire_returned(struct mm_struct *mm, bool write,
22 bool success);
23void __mmap_lock_do_trace_released(struct mm_struct *mm, bool write);
24
25static inline void __mmap_lock_trace_start_locking(struct mm_struct *mm,
26 bool write)
27{
28 if (tracepoint_enabled(mmap_lock_start_locking))
29 __mmap_lock_do_trace_start_locking(mm, write);
30}
31
32static inline void __mmap_lock_trace_acquire_returned(struct mm_struct *mm,
33 bool write, bool success)
34{
35 if (tracepoint_enabled(mmap_lock_acquire_returned))
36 __mmap_lock_do_trace_acquire_returned(mm, write, success);
37}
38
39static inline void __mmap_lock_trace_released(struct mm_struct *mm, bool write)
40{
41 if (tracepoint_enabled(mmap_lock_released))
42 __mmap_lock_do_trace_released(mm, write);
43}
44
45#else /* !CONFIG_TRACING */
46
47static inline void __mmap_lock_trace_start_locking(struct mm_struct *mm,
48 bool write)
49{
50}
51
52static inline void __mmap_lock_trace_acquire_returned(struct mm_struct *mm,
53 bool write, bool success)
54{
55}
56
57static inline void __mmap_lock_trace_released(struct mm_struct *mm, bool write)
58{
59}
60
61#endif /* CONFIG_TRACING */
62
63static inline void mmap_assert_locked(struct mm_struct *mm)
64{
65 lockdep_assert_held(&mm->mmap_lock);
66 VM_BUG_ON_MM(!rwsem_is_locked(&mm->mmap_lock), mm);
67}
68
69static inline void mmap_assert_write_locked(struct mm_struct *mm)
70{
71 lockdep_assert_held_write(&mm->mmap_lock);
72 VM_BUG_ON_MM(!rwsem_is_locked(&mm->mmap_lock), mm);
73}
74
75#ifdef CONFIG_PER_VMA_LOCK
76static inline void vma_end_write_all(struct mm_struct *mm)
77{
78 mmap_assert_write_locked(mm);
79 /* No races during update due to exclusive mmap_lock being held */
80 WRITE_ONCE(mm->mm_lock_seq, mm->mm_lock_seq + 1);
81}
82#else
83static inline void vma_end_write_all(struct mm_struct *mm) {}
84#endif
85
86static inline void mmap_init_lock(struct mm_struct *mm)
87{
88 init_rwsem(&mm->mmap_lock);
89}
90
91static inline void mmap_write_lock(struct mm_struct *mm)
92{
93 __mmap_lock_trace_start_locking(mm, true);
94 down_write(&mm->mmap_lock);
95 __mmap_lock_trace_acquire_returned(mm, true, true);
96}
97
98static inline void mmap_write_lock_nested(struct mm_struct *mm, int subclass)
99{
100 __mmap_lock_trace_start_locking(mm, true);
101 down_write_nested(&mm->mmap_lock, subclass);
102 __mmap_lock_trace_acquire_returned(mm, true, true);
103}
104
105static inline int mmap_write_lock_killable(struct mm_struct *mm)
106{
107 int ret;
108
109 __mmap_lock_trace_start_locking(mm, true);
110 ret = down_write_killable(&mm->mmap_lock);
111 __mmap_lock_trace_acquire_returned(mm, true, ret == 0);
112 return ret;
113}
114
115static inline bool mmap_write_trylock(struct mm_struct *mm)
116{
117 bool ret;
118
119 __mmap_lock_trace_start_locking(mm, true);
120 ret = down_write_trylock(&mm->mmap_lock) != 0;
121 __mmap_lock_trace_acquire_returned(mm, true, ret);
122 return ret;
123}
124
125static inline void mmap_write_unlock(struct mm_struct *mm)
126{
127 __mmap_lock_trace_released(mm, true);
128 vma_end_write_all(mm);
129 up_write(&mm->mmap_lock);
130}
131
132static inline void mmap_write_downgrade(struct mm_struct *mm)
133{
134 __mmap_lock_trace_acquire_returned(mm, false, true);
135 vma_end_write_all(mm);
136 downgrade_write(&mm->mmap_lock);
137}
138
139static inline void mmap_read_lock(struct mm_struct *mm)
140{
141 __mmap_lock_trace_start_locking(mm, false);
142 down_read(&mm->mmap_lock);
143 __mmap_lock_trace_acquire_returned(mm, false, true);
144}
145
146static inline int mmap_read_lock_killable(struct mm_struct *mm)
147{
148 int ret;
149
150 __mmap_lock_trace_start_locking(mm, false);
151 ret = down_read_killable(&mm->mmap_lock);
152 __mmap_lock_trace_acquire_returned(mm, false, ret == 0);
153 return ret;
154}
155
156static inline bool mmap_read_trylock(struct mm_struct *mm)
157{
158 bool ret;
159
160 __mmap_lock_trace_start_locking(mm, false);
161 ret = down_read_trylock(&mm->mmap_lock) != 0;
162 __mmap_lock_trace_acquire_returned(mm, false, ret);
163 return ret;
164}
165
166static inline void mmap_read_unlock(struct mm_struct *mm)
167{
168 __mmap_lock_trace_released(mm, false);
169 up_read(&mm->mmap_lock);
170}
171
172static inline void mmap_read_unlock_non_owner(struct mm_struct *mm)
173{
174 __mmap_lock_trace_released(mm, false);
175 up_read_non_owner(&mm->mmap_lock);
176}
177
178static inline int mmap_lock_is_contended(struct mm_struct *mm)
179{
180 return rwsem_is_contended(&mm->mmap_lock);
181}
182
183#endif /* _LINUX_MMAP_LOCK_H */