1 #ifndef _LINUX_MMAP_LOCK_H
2 #define _LINUX_MMAP_LOCK_H
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>
11 #define MMAP_LOCK_INITIALIZER(name) \
12 .mmap_lock = __RWSEM_INITIALIZER((name).mmap_lock),
14 DECLARE_TRACEPOINT(mmap_lock_start_locking);
15 DECLARE_TRACEPOINT(mmap_lock_acquire_returned);
16 DECLARE_TRACEPOINT(mmap_lock_released);
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,
23 void __mmap_lock_do_trace_released(struct mm_struct *mm, bool write);
25 static inline void __mmap_lock_trace_start_locking(struct mm_struct *mm,
28 if (tracepoint_enabled(mmap_lock_start_locking))
29 __mmap_lock_do_trace_start_locking(mm, write);
32 static inline void __mmap_lock_trace_acquire_returned(struct mm_struct *mm,
33 bool write, bool success)
35 if (tracepoint_enabled(mmap_lock_acquire_returned))
36 __mmap_lock_do_trace_acquire_returned(mm, write, success);
39 static inline void __mmap_lock_trace_released(struct mm_struct *mm, bool write)
41 if (tracepoint_enabled(mmap_lock_released))
42 __mmap_lock_do_trace_released(mm, write);
45 #else /* !CONFIG_TRACING */
47 static inline void __mmap_lock_trace_start_locking(struct mm_struct *mm,
52 static inline void __mmap_lock_trace_acquire_returned(struct mm_struct *mm,
53 bool write, bool success)
57 static inline void __mmap_lock_trace_released(struct mm_struct *mm, bool write)
61 #endif /* CONFIG_TRACING */
63 static inline void mmap_assert_locked(struct mm_struct *mm)
65 lockdep_assert_held(&mm->mmap_lock);
66 VM_BUG_ON_MM(!rwsem_is_locked(&mm->mmap_lock), mm);
69 static inline void mmap_assert_write_locked(struct mm_struct *mm)
71 lockdep_assert_held_write(&mm->mmap_lock);
72 VM_BUG_ON_MM(!rwsem_is_locked(&mm->mmap_lock), mm);
75 #ifdef CONFIG_PER_VMA_LOCK
76 static inline void vma_end_write_all(struct mm_struct *mm)
78 mmap_assert_write_locked(mm);
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().
86 smp_store_release(&mm->mm_lock_seq, mm->mm_lock_seq + 1);
89 static inline void vma_end_write_all(struct mm_struct *mm) {}
92 static inline void mmap_init_lock(struct mm_struct *mm)
94 init_rwsem(&mm->mmap_lock);
97 static inline void mmap_write_lock(struct mm_struct *mm)
99 __mmap_lock_trace_start_locking(mm, true);
100 down_write(&mm->mmap_lock);
101 __mmap_lock_trace_acquire_returned(mm, true, true);
104 static inline void mmap_write_lock_nested(struct mm_struct *mm, int subclass)
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);
111 static inline int mmap_write_lock_killable(struct mm_struct *mm)
115 __mmap_lock_trace_start_locking(mm, true);
116 ret = down_write_killable(&mm->mmap_lock);
117 __mmap_lock_trace_acquire_returned(mm, true, ret == 0);
121 static inline bool mmap_write_trylock(struct mm_struct *mm)
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);
131 static inline void mmap_write_unlock(struct mm_struct *mm)
133 __mmap_lock_trace_released(mm, true);
134 vma_end_write_all(mm);
135 up_write(&mm->mmap_lock);
138 static inline void mmap_write_downgrade(struct mm_struct *mm)
140 __mmap_lock_trace_acquire_returned(mm, false, true);
141 vma_end_write_all(mm);
142 downgrade_write(&mm->mmap_lock);
145 static inline void mmap_read_lock(struct mm_struct *mm)
147 __mmap_lock_trace_start_locking(mm, false);
148 down_read(&mm->mmap_lock);
149 __mmap_lock_trace_acquire_returned(mm, false, true);
152 static inline int mmap_read_lock_killable(struct mm_struct *mm)
156 __mmap_lock_trace_start_locking(mm, false);
157 ret = down_read_killable(&mm->mmap_lock);
158 __mmap_lock_trace_acquire_returned(mm, false, ret == 0);
162 static inline bool mmap_read_trylock(struct mm_struct *mm)
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);
172 static inline void mmap_read_unlock(struct mm_struct *mm)
174 __mmap_lock_trace_released(mm, false);
175 up_read(&mm->mmap_lock);
178 static inline void mmap_read_unlock_non_owner(struct mm_struct *mm)
180 __mmap_lock_trace_released(mm, false);
181 up_read_non_owner(&mm->mmap_lock);
184 static inline int mmap_lock_is_contended(struct mm_struct *mm)
186 return rwsem_is_contended(&mm->mmap_lock);
189 #endif /* _LINUX_MMAP_LOCK_H */