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(const struct mm_struct *mm)
64 { 64 {
65 rwsem_assert_held(&mm->mmap_lock); 65 rwsem_assert_held(&mm->mmap_lock);
66 } 66 }
67 67
68 static inline void mmap_assert_write_locked(co 68 static inline void mmap_assert_write_locked(const struct mm_struct *mm)
69 { 69 {
70 rwsem_assert_held_write(&mm->mmap_lock 70 rwsem_assert_held_write(&mm->mmap_lock);
71 } 71 }
72 72
73 #ifdef CONFIG_PER_VMA_LOCK 73 #ifdef CONFIG_PER_VMA_LOCK
74 /* 74 /*
75 * Drop all currently-held per-VMA locks. 75 * Drop all currently-held per-VMA locks.
76 * This is called from the mmap_lock implement 76 * This is called from the mmap_lock implementation directly before releasing
77 * a write-locked mmap_lock (or downgrading it 77 * a write-locked mmap_lock (or downgrading it to read-locked).
78 * This should normally NOT be called manually 78 * This should normally NOT be called manually from other places.
79 * If you want to call this manually anyway, k 79 * If you want to call this manually anyway, keep in mind that this will release
80 * *all* VMA write locks, including ones from 80 * *all* VMA write locks, including ones from further up the stack.
81 */ 81 */
82 static inline void vma_end_write_all(struct mm 82 static inline void vma_end_write_all(struct mm_struct *mm)
83 { 83 {
84 mmap_assert_write_locked(mm); 84 mmap_assert_write_locked(mm);
85 /* 85 /*
86 * Nobody can concurrently modify mm-> 86 * Nobody can concurrently modify mm->mm_lock_seq due to exclusive
87 * mmap_lock being held. 87 * mmap_lock being held.
88 * We need RELEASE semantics here to e 88 * We need RELEASE semantics here to ensure that preceding stores into
89 * the VMA take effect before we unloc 89 * the VMA take effect before we unlock it with this store.
90 * Pairs with ACQUIRE semantics in vma 90 * Pairs with ACQUIRE semantics in vma_start_read().
91 */ 91 */
92 smp_store_release(&mm->mm_lock_seq, mm 92 smp_store_release(&mm->mm_lock_seq, mm->mm_lock_seq + 1);
93 } 93 }
94 #else 94 #else
95 static inline void vma_end_write_all(struct mm 95 static inline void vma_end_write_all(struct mm_struct *mm) {}
96 #endif 96 #endif
97 97
98 static inline void mmap_init_lock(struct mm_st 98 static inline void mmap_init_lock(struct mm_struct *mm)
99 { 99 {
100 init_rwsem(&mm->mmap_lock); 100 init_rwsem(&mm->mmap_lock);
101 } 101 }
102 102
103 static inline void mmap_write_lock(struct mm_s 103 static inline void mmap_write_lock(struct mm_struct *mm)
104 { 104 {
105 __mmap_lock_trace_start_locking(mm, tr 105 __mmap_lock_trace_start_locking(mm, true);
106 down_write(&mm->mmap_lock); 106 down_write(&mm->mmap_lock);
107 __mmap_lock_trace_acquire_returned(mm, 107 __mmap_lock_trace_acquire_returned(mm, true, true);
108 } 108 }
109 109
110 static inline void mmap_write_lock_nested(stru 110 static inline void mmap_write_lock_nested(struct mm_struct *mm, int subclass)
111 { 111 {
112 __mmap_lock_trace_start_locking(mm, tr 112 __mmap_lock_trace_start_locking(mm, true);
113 down_write_nested(&mm->mmap_lock, subc 113 down_write_nested(&mm->mmap_lock, subclass);
114 __mmap_lock_trace_acquire_returned(mm, 114 __mmap_lock_trace_acquire_returned(mm, true, true);
115 } 115 }
116 116
117 static inline int mmap_write_lock_killable(str 117 static inline int mmap_write_lock_killable(struct mm_struct *mm)
118 { 118 {
119 int ret; 119 int ret;
120 120
121 __mmap_lock_trace_start_locking(mm, tr 121 __mmap_lock_trace_start_locking(mm, true);
122 ret = down_write_killable(&mm->mmap_lo 122 ret = down_write_killable(&mm->mmap_lock);
123 __mmap_lock_trace_acquire_returned(mm, 123 __mmap_lock_trace_acquire_returned(mm, true, ret == 0);
124 return ret; 124 return ret;
125 } 125 }
126 126
127 static inline void mmap_write_unlock(struct mm 127 static inline void mmap_write_unlock(struct mm_struct *mm)
128 { 128 {
129 __mmap_lock_trace_released(mm, true); 129 __mmap_lock_trace_released(mm, true);
130 vma_end_write_all(mm); 130 vma_end_write_all(mm);
131 up_write(&mm->mmap_lock); 131 up_write(&mm->mmap_lock);
132 } 132 }
133 133
134 static inline void mmap_write_downgrade(struct 134 static inline void mmap_write_downgrade(struct mm_struct *mm)
135 { 135 {
136 __mmap_lock_trace_acquire_returned(mm, 136 __mmap_lock_trace_acquire_returned(mm, false, true);
137 vma_end_write_all(mm); 137 vma_end_write_all(mm);
138 downgrade_write(&mm->mmap_lock); 138 downgrade_write(&mm->mmap_lock);
139 } 139 }
140 140
141 static inline void mmap_read_lock(struct mm_st 141 static inline void mmap_read_lock(struct mm_struct *mm)
142 { 142 {
143 __mmap_lock_trace_start_locking(mm, fa 143 __mmap_lock_trace_start_locking(mm, false);
144 down_read(&mm->mmap_lock); 144 down_read(&mm->mmap_lock);
145 __mmap_lock_trace_acquire_returned(mm, 145 __mmap_lock_trace_acquire_returned(mm, false, true);
146 } 146 }
147 147
148 static inline int mmap_read_lock_killable(stru 148 static inline int mmap_read_lock_killable(struct mm_struct *mm)
149 { 149 {
150 int ret; 150 int ret;
151 151
152 __mmap_lock_trace_start_locking(mm, fa 152 __mmap_lock_trace_start_locking(mm, false);
153 ret = down_read_killable(&mm->mmap_loc 153 ret = down_read_killable(&mm->mmap_lock);
154 __mmap_lock_trace_acquire_returned(mm, 154 __mmap_lock_trace_acquire_returned(mm, false, ret == 0);
155 return ret; 155 return ret;
156 } 156 }
157 157
158 static inline bool mmap_read_trylock(struct mm 158 static inline bool mmap_read_trylock(struct mm_struct *mm)
159 { 159 {
160 bool ret; 160 bool ret;
161 161
162 __mmap_lock_trace_start_locking(mm, fa 162 __mmap_lock_trace_start_locking(mm, false);
163 ret = down_read_trylock(&mm->mmap_lock 163 ret = down_read_trylock(&mm->mmap_lock) != 0;
164 __mmap_lock_trace_acquire_returned(mm, 164 __mmap_lock_trace_acquire_returned(mm, false, ret);
165 return ret; 165 return ret;
166 } 166 }
167 167
168 static inline void mmap_read_unlock(struct mm_ 168 static inline void mmap_read_unlock(struct mm_struct *mm)
169 { 169 {
170 __mmap_lock_trace_released(mm, false); 170 __mmap_lock_trace_released(mm, false);
171 up_read(&mm->mmap_lock); 171 up_read(&mm->mmap_lock);
172 } 172 }
173 173
174 static inline void mmap_read_unlock_non_owner( 174 static inline void mmap_read_unlock_non_owner(struct mm_struct *mm)
175 { 175 {
176 __mmap_lock_trace_released(mm, false); 176 __mmap_lock_trace_released(mm, false);
177 up_read_non_owner(&mm->mmap_lock); 177 up_read_non_owner(&mm->mmap_lock);
178 } 178 }
179 179
180 static inline int mmap_lock_is_contended(struc 180 static inline int mmap_lock_is_contended(struct mm_struct *mm)
181 { 181 {
182 return rwsem_is_contended(&mm->mmap_lo 182 return rwsem_is_contended(&mm->mmap_lock);
183 } 183 }
184 184
185 #endif /* _LINUX_MMAP_LOCK_H */ 185 #endif /* _LINUX_MMAP_LOCK_H */
186 186
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