Line data Source code
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 :
14 : DECLARE_TRACEPOINT(mmap_lock_start_locking);
15 : DECLARE_TRACEPOINT(mmap_lock_acquire_returned);
16 : DECLARE_TRACEPOINT(mmap_lock_released);
17 :
18 : #ifdef CONFIG_TRACING
19 :
20 : void __mmap_lock_do_trace_start_locking(struct mm_struct *mm, bool write);
21 : void __mmap_lock_do_trace_acquire_returned(struct mm_struct *mm, bool write,
22 : bool success);
23 : void __mmap_lock_do_trace_released(struct mm_struct *mm, bool write);
24 :
25 322547305 : static inline void __mmap_lock_trace_start_locking(struct mm_struct *mm,
26 : bool write)
27 : {
28 322547305 : if (tracepoint_enabled(mmap_lock_start_locking))
29 0 : __mmap_lock_do_trace_start_locking(mm, write);
30 322596163 : }
31 :
32 369778146 : static inline void __mmap_lock_trace_acquire_returned(struct mm_struct *mm,
33 : bool write, bool success)
34 : {
35 369778146 : if (tracepoint_enabled(mmap_lock_acquire_returned))
36 0 : __mmap_lock_do_trace_acquire_returned(mm, write, success);
37 369774776 : }
38 :
39 330743546 : static inline void __mmap_lock_trace_released(struct mm_struct *mm, bool write)
40 : {
41 330743546 : if (tracepoint_enabled(mmap_lock_released))
42 0 : __mmap_lock_do_trace_released(mm, write);
43 330738420 : }
44 :
45 : #else /* !CONFIG_TRACING */
46 :
47 : static inline void __mmap_lock_trace_start_locking(struct mm_struct *mm,
48 : bool write)
49 : {
50 : }
51 :
52 : static inline void __mmap_lock_trace_acquire_returned(struct mm_struct *mm,
53 : bool write, bool success)
54 : {
55 : }
56 :
57 : static inline void __mmap_lock_trace_released(struct mm_struct *mm, bool write)
58 : {
59 : }
60 :
61 : #endif /* CONFIG_TRACING */
62 :
63 : static 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 :
69 : static 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
76 : static inline void vma_end_write_all(struct mm_struct *mm)
77 : {
78 162637919 : mmap_assert_write_locked(mm);
79 : /*
80 : * Nobody can concurrently modify mm->mm_lock_seq due to exclusive
81 : * mmap_lock being held.
82 : * We need RELEASE semantics here to ensure that preceding stores into
83 : * the VMA take effect before we unlock it with this store.
84 : * Pairs with ACQUIRE semantics in vma_start_read().
85 : */
86 325277482 : smp_store_release(&mm->mm_lock_seq, mm->mm_lock_seq + 1);
87 : }
88 : #else
89 : static inline void vma_end_write_all(struct mm_struct *mm) {}
90 : #endif
91 :
92 : static inline void mmap_init_lock(struct mm_struct *mm)
93 : {
94 : init_rwsem(&mm->mmap_lock);
95 : }
96 :
97 47177927 : static inline void mmap_write_lock(struct mm_struct *mm)
98 : {
99 47177927 : __mmap_lock_trace_start_locking(mm, true);
100 47182786 : down_write(&mm->mmap_lock);
101 47184873 : __mmap_lock_trace_acquire_returned(mm, true, true);
102 47183250 : }
103 :
104 : static inline void mmap_write_lock_nested(struct mm_struct *mm, int subclass)
105 : {
106 : __mmap_lock_trace_start_locking(mm, true);
107 : down_write_nested(&mm->mmap_lock, subclass);
108 : __mmap_lock_trace_acquire_returned(mm, true, true);
109 : }
110 :
111 115542645 : static inline int mmap_write_lock_killable(struct mm_struct *mm)
112 : {
113 115542645 : int ret;
114 :
115 115542645 : __mmap_lock_trace_start_locking(mm, true);
116 115539268 : ret = down_write_killable(&mm->mmap_lock);
117 115553293 : __mmap_lock_trace_acquire_returned(mm, true, ret == 0);
118 115550093 : return ret;
119 : }
120 :
121 : static inline bool mmap_write_trylock(struct mm_struct *mm)
122 : {
123 : bool ret;
124 :
125 : __mmap_lock_trace_start_locking(mm, true);
126 : ret = down_write_trylock(&mm->mmap_lock) != 0;
127 : __mmap_lock_trace_acquire_returned(mm, true, ret);
128 : return ret;
129 : }
130 :
131 115524787 : static inline void mmap_write_unlock(struct mm_struct *mm)
132 : {
133 115524787 : __mmap_lock_trace_released(mm, true);
134 115474943 : vma_end_write_all(mm);
135 115476673 : up_write(&mm->mmap_lock);
136 115531729 : }
137 :
138 47165178 : static inline void mmap_write_downgrade(struct mm_struct *mm)
139 : {
140 47165178 : __mmap_lock_trace_acquire_returned(mm, false, true);
141 47162976 : vma_end_write_all(mm);
142 47162890 : downgrade_write(&mm->mmap_lock);
143 47164415 : }
144 :
145 123207272 : static inline void mmap_read_lock(struct mm_struct *mm)
146 : {
147 123207272 : __mmap_lock_trace_start_locking(mm, false);
148 123197127 : down_read(&mm->mmap_lock);
149 123209694 : __mmap_lock_trace_acquire_returned(mm, false, true);
150 123204119 : }
151 :
152 36684573 : static inline int mmap_read_lock_killable(struct mm_struct *mm)
153 : {
154 36684573 : int ret;
155 :
156 36684573 : __mmap_lock_trace_start_locking(mm, false);
157 36680861 : ret = down_read_killable(&mm->mmap_lock);
158 36681504 : __mmap_lock_trace_acquire_returned(mm, false, ret == 0);
159 36678697 : return ret;
160 : }
161 :
162 : static inline bool mmap_read_trylock(struct mm_struct *mm)
163 : {
164 : bool ret;
165 :
166 : __mmap_lock_trace_start_locking(mm, false);
167 : ret = down_read_trylock(&mm->mmap_lock) != 0;
168 : __mmap_lock_trace_acquire_returned(mm, false, ret);
169 : return ret;
170 : }
171 :
172 215264624 : static inline void mmap_read_unlock(struct mm_struct *mm)
173 : {
174 215264624 : __mmap_lock_trace_released(mm, false);
175 215243167 : up_read(&mm->mmap_lock);
176 215256603 : }
177 :
178 : static inline void mmap_read_unlock_non_owner(struct mm_struct *mm)
179 : {
180 : __mmap_lock_trace_released(mm, false);
181 : up_read_non_owner(&mm->mmap_lock);
182 : }
183 :
184 : static inline int mmap_lock_is_contended(struct mm_struct *mm)
185 : {
186 : return rwsem_is_contended(&mm->mmap_lock);
187 : }
188 :
189 : #endif /* _LINUX_MMAP_LOCK_H */
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