1 #ifndef _LINUX_MMAP_LOCK_H 1 #ifndef _LINUX_MMAP_LOCK_H
2 #define _LINUX_MMAP_LOCK_H 2 #define _LINUX_MMAP_LOCK_H
3 3
4 #include <linux/lockdep.h> 4 #include <linux/lockdep.h>
5 #include <linux/mm_types.h> 5 #include <linux/mm_types.h>
6 #include <linux/mmdebug.h> 6 #include <linux/mmdebug.h>
7 #include <linux/rwsem.h> 7 #include <linux/rwsem.h>
8 #include <linux/tracepoint-defs.h> 8 #include <linux/tracepoint-defs.h>
9 #include <linux/types.h> 9 #include <linux/types.h>
10 10
11 #define MMAP_LOCK_INITIALIZER(name) \ 11 #define MMAP_LOCK_INITIALIZER(name) \
12 .mmap_lock = __RWSEM_INITIALIZER((name 12 .mmap_lock = __RWSEM_INITIALIZER((name).mmap_lock),
13 13
14 DECLARE_TRACEPOINT(mmap_lock_start_locking); 14 DECLARE_TRACEPOINT(mmap_lock_start_locking);
15 DECLARE_TRACEPOINT(mmap_lock_acquire_returned) 15 DECLARE_TRACEPOINT(mmap_lock_acquire_returned);
16 DECLARE_TRACEPOINT(mmap_lock_released); 16 DECLARE_TRACEPOINT(mmap_lock_released);
17 17
18 #ifdef CONFIG_TRACING 18 #ifdef CONFIG_TRACING
19 19
20 void __mmap_lock_do_trace_start_locking(struct 20 void __mmap_lock_do_trace_start_locking(struct mm_struct *mm, bool write);
21 void __mmap_lock_do_trace_acquire_returned(str 21 void __mmap_lock_do_trace_acquire_returned(struct mm_struct *mm, bool write,
22 boo 22 bool success);
23 void __mmap_lock_do_trace_released(struct mm_s 23 void __mmap_lock_do_trace_released(struct mm_struct *mm, bool write);
24 24
25 static inline void __mmap_lock_trace_start_loc 25 static inline void __mmap_lock_trace_start_locking(struct mm_struct *mm,
26 26 bool write)
27 { 27 {
28 if (tracepoint_enabled(mmap_lock_start 28 if (tracepoint_enabled(mmap_lock_start_locking))
29 __mmap_lock_do_trace_start_loc 29 __mmap_lock_do_trace_start_locking(mm, write);
30 } 30 }
31 31
32 static inline void __mmap_lock_trace_acquire_r 32 static inline void __mmap_lock_trace_acquire_returned(struct mm_struct *mm,
33 33 bool write, bool success)
34 { 34 {
35 if (tracepoint_enabled(mmap_lock_acqui 35 if (tracepoint_enabled(mmap_lock_acquire_returned))
36 __mmap_lock_do_trace_acquire_r 36 __mmap_lock_do_trace_acquire_returned(mm, write, success);
37 } 37 }
38 38
39 static inline void __mmap_lock_trace_released( 39 static inline void __mmap_lock_trace_released(struct mm_struct *mm, bool write)
40 { 40 {
41 if (tracepoint_enabled(mmap_lock_relea 41 if (tracepoint_enabled(mmap_lock_released))
42 __mmap_lock_do_trace_released( 42 __mmap_lock_do_trace_released(mm, write);
43 } 43 }
44 44
45 #else /* !CONFIG_TRACING */ 45 #else /* !CONFIG_TRACING */
46 46
47 static inline void __mmap_lock_trace_start_loc 47 static inline void __mmap_lock_trace_start_locking(struct mm_struct *mm,
48 48 bool write)
49 { 49 {
50 } 50 }
51 51
52 static inline void __mmap_lock_trace_acquire_r 52 static inline void __mmap_lock_trace_acquire_returned(struct mm_struct *mm,
53 53 bool write, bool success)
54 { 54 {
55 } 55 }
56 56
57 static inline void __mmap_lock_trace_released( 57 static inline void __mmap_lock_trace_released(struct mm_struct *mm, bool write)
58 { 58 {
59 } 59 }
60 60
61 #endif /* CONFIG_TRACING */ 61 #endif /* CONFIG_TRACING */
62 62
63 static inline void mmap_assert_locked(const st !! 63 static inline void mmap_assert_locked(struct mm_struct *mm)
64 { 64 {
65 rwsem_assert_held(&mm->mmap_lock); !! 65 lockdep_assert_held(&mm->mmap_lock);
>> 66 VM_BUG_ON_MM(!rwsem_is_locked(&mm->mmap_lock), mm);
66 } 67 }
67 68
68 static inline void mmap_assert_write_locked(co !! 69 static inline void mmap_assert_write_locked(struct mm_struct *mm)
69 { 70 {
70 rwsem_assert_held_write(&mm->mmap_lock !! 71 lockdep_assert_held_write(&mm->mmap_lock);
>> 72 VM_BUG_ON_MM(!rwsem_is_locked(&mm->mmap_lock), mm);
71 } 73 }
72 74
73 #ifdef CONFIG_PER_VMA_LOCK 75 #ifdef CONFIG_PER_VMA_LOCK
74 /* 76 /*
75 * Drop all currently-held per-VMA locks. 77 * Drop all currently-held per-VMA locks.
76 * This is called from the mmap_lock implement 78 * This is called from the mmap_lock implementation directly before releasing
77 * a write-locked mmap_lock (or downgrading it 79 * a write-locked mmap_lock (or downgrading it to read-locked).
78 * This should normally NOT be called manually 80 * This should normally NOT be called manually from other places.
79 * If you want to call this manually anyway, k 81 * If you want to call this manually anyway, keep in mind that this will release
80 * *all* VMA write locks, including ones from 82 * *all* VMA write locks, including ones from further up the stack.
81 */ 83 */
82 static inline void vma_end_write_all(struct mm 84 static inline void vma_end_write_all(struct mm_struct *mm)
83 { 85 {
84 mmap_assert_write_locked(mm); 86 mmap_assert_write_locked(mm);
85 /* 87 /*
86 * Nobody can concurrently modify mm-> 88 * Nobody can concurrently modify mm->mm_lock_seq due to exclusive
87 * mmap_lock being held. 89 * mmap_lock being held.
88 * We need RELEASE semantics here to e 90 * We need RELEASE semantics here to ensure that preceding stores into
89 * the VMA take effect before we unloc 91 * the VMA take effect before we unlock it with this store.
90 * Pairs with ACQUIRE semantics in vma 92 * Pairs with ACQUIRE semantics in vma_start_read().
91 */ 93 */
92 smp_store_release(&mm->mm_lock_seq, mm 94 smp_store_release(&mm->mm_lock_seq, mm->mm_lock_seq + 1);
93 } 95 }
94 #else 96 #else
95 static inline void vma_end_write_all(struct mm 97 static inline void vma_end_write_all(struct mm_struct *mm) {}
96 #endif 98 #endif
97 99
98 static inline void mmap_init_lock(struct mm_st 100 static inline void mmap_init_lock(struct mm_struct *mm)
99 { 101 {
100 init_rwsem(&mm->mmap_lock); 102 init_rwsem(&mm->mmap_lock);
101 } 103 }
102 104
103 static inline void mmap_write_lock(struct mm_s 105 static inline void mmap_write_lock(struct mm_struct *mm)
104 { 106 {
105 __mmap_lock_trace_start_locking(mm, tr 107 __mmap_lock_trace_start_locking(mm, true);
106 down_write(&mm->mmap_lock); 108 down_write(&mm->mmap_lock);
107 __mmap_lock_trace_acquire_returned(mm, 109 __mmap_lock_trace_acquire_returned(mm, true, true);
108 } 110 }
109 111
110 static inline void mmap_write_lock_nested(stru 112 static inline void mmap_write_lock_nested(struct mm_struct *mm, int subclass)
111 { 113 {
112 __mmap_lock_trace_start_locking(mm, tr 114 __mmap_lock_trace_start_locking(mm, true);
113 down_write_nested(&mm->mmap_lock, subc 115 down_write_nested(&mm->mmap_lock, subclass);
114 __mmap_lock_trace_acquire_returned(mm, 116 __mmap_lock_trace_acquire_returned(mm, true, true);
115 } 117 }
116 118
117 static inline int mmap_write_lock_killable(str 119 static inline int mmap_write_lock_killable(struct mm_struct *mm)
118 { 120 {
119 int ret; 121 int ret;
120 122
121 __mmap_lock_trace_start_locking(mm, tr 123 __mmap_lock_trace_start_locking(mm, true);
122 ret = down_write_killable(&mm->mmap_lo 124 ret = down_write_killable(&mm->mmap_lock);
123 __mmap_lock_trace_acquire_returned(mm, 125 __mmap_lock_trace_acquire_returned(mm, true, ret == 0);
124 return ret; 126 return ret;
125 } 127 }
126 128
127 static inline void mmap_write_unlock(struct mm 129 static inline void mmap_write_unlock(struct mm_struct *mm)
128 { 130 {
129 __mmap_lock_trace_released(mm, true); 131 __mmap_lock_trace_released(mm, true);
130 vma_end_write_all(mm); 132 vma_end_write_all(mm);
131 up_write(&mm->mmap_lock); 133 up_write(&mm->mmap_lock);
132 } 134 }
133 135
134 static inline void mmap_write_downgrade(struct 136 static inline void mmap_write_downgrade(struct mm_struct *mm)
135 { 137 {
136 __mmap_lock_trace_acquire_returned(mm, 138 __mmap_lock_trace_acquire_returned(mm, false, true);
137 vma_end_write_all(mm); 139 vma_end_write_all(mm);
138 downgrade_write(&mm->mmap_lock); 140 downgrade_write(&mm->mmap_lock);
139 } 141 }
140 142
141 static inline void mmap_read_lock(struct mm_st 143 static inline void mmap_read_lock(struct mm_struct *mm)
142 { 144 {
143 __mmap_lock_trace_start_locking(mm, fa 145 __mmap_lock_trace_start_locking(mm, false);
144 down_read(&mm->mmap_lock); 146 down_read(&mm->mmap_lock);
145 __mmap_lock_trace_acquire_returned(mm, 147 __mmap_lock_trace_acquire_returned(mm, false, true);
146 } 148 }
147 149
148 static inline int mmap_read_lock_killable(stru 150 static inline int mmap_read_lock_killable(struct mm_struct *mm)
149 { 151 {
150 int ret; 152 int ret;
151 153
152 __mmap_lock_trace_start_locking(mm, fa 154 __mmap_lock_trace_start_locking(mm, false);
153 ret = down_read_killable(&mm->mmap_loc 155 ret = down_read_killable(&mm->mmap_lock);
154 __mmap_lock_trace_acquire_returned(mm, 156 __mmap_lock_trace_acquire_returned(mm, false, ret == 0);
155 return ret; 157 return ret;
156 } 158 }
157 159
158 static inline bool mmap_read_trylock(struct mm 160 static inline bool mmap_read_trylock(struct mm_struct *mm)
159 { 161 {
160 bool ret; 162 bool ret;
161 163
162 __mmap_lock_trace_start_locking(mm, fa 164 __mmap_lock_trace_start_locking(mm, false);
163 ret = down_read_trylock(&mm->mmap_lock 165 ret = down_read_trylock(&mm->mmap_lock) != 0;
164 __mmap_lock_trace_acquire_returned(mm, 166 __mmap_lock_trace_acquire_returned(mm, false, ret);
165 return ret; 167 return ret;
166 } 168 }
167 169
168 static inline void mmap_read_unlock(struct mm_ 170 static inline void mmap_read_unlock(struct mm_struct *mm)
169 { 171 {
170 __mmap_lock_trace_released(mm, false); 172 __mmap_lock_trace_released(mm, false);
171 up_read(&mm->mmap_lock); 173 up_read(&mm->mmap_lock);
172 } 174 }
173 175
174 static inline void mmap_read_unlock_non_owner( 176 static inline void mmap_read_unlock_non_owner(struct mm_struct *mm)
175 { 177 {
176 __mmap_lock_trace_released(mm, false); 178 __mmap_lock_trace_released(mm, false);
177 up_read_non_owner(&mm->mmap_lock); 179 up_read_non_owner(&mm->mmap_lock);
178 } 180 }
179 181
180 static inline int mmap_lock_is_contended(struc 182 static inline int mmap_lock_is_contended(struct mm_struct *mm)
181 { 183 {
182 return rwsem_is_contended(&mm->mmap_lo 184 return rwsem_is_contended(&mm->mmap_lock);
183 } 185 }
184 186
185 #endif /* _LINUX_MMAP_LOCK_H */ 187 #endif /* _LINUX_MMAP_LOCK_H */
186 188
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