include/linux/mmap_lock.h

   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 static 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
  32 static 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
  39 static 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
  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_init_lock(struct mm_struct *mm)
  64 {
  65         init_rwsem(&mm->mmap_lock);
  66 }
  67
  68 static inline void mmap_write_lock(struct mm_struct *mm)
  69 {
  70         __mmap_lock_trace_start_locking(mm, true);
  71         down_write(&mm->mmap_lock);
  72         __mmap_lock_trace_acquire_returned(mm, true, true);
  73 }
  74
  75 static inline void mmap_write_lock_nested(struct mm_struct *mm, int subclass)
  76 {
  77         __mmap_lock_trace_start_locking(mm, true);
  78         down_write_nested(&mm->mmap_lock, subclass);
  79         __mmap_lock_trace_acquire_returned(mm, true, true);
  80 }
  81
  82 static inline int mmap_write_lock_killable(struct mm_struct *mm)
  83 {
  84         int ret;
  85
  86         __mmap_lock_trace_start_locking(mm, true);
  87         ret = down_write_killable(&mm->mmap_lock);
  88         __mmap_lock_trace_acquire_returned(mm, true, ret == 0);
  89         return ret;
  90 }
  91
  92 static inline bool mmap_write_trylock(struct mm_struct *mm)
  93 {
  94         bool ret;
  95
  96         __mmap_lock_trace_start_locking(mm, true);
  97         ret = down_write_trylock(&mm->mmap_lock) != 0;
  98         __mmap_lock_trace_acquire_returned(mm, true, ret);
  99         return ret;
 100 }
 101
 102 static inline void mmap_write_unlock(struct mm_struct *mm)
 103 {
 104         __mmap_lock_trace_released(mm, true);
 105         up_write(&mm->mmap_lock);
 106 }
 107
 108 static inline void mmap_write_downgrade(struct mm_struct *mm)
 109 {
 110         __mmap_lock_trace_acquire_returned(mm, false, true);
 111         downgrade_write(&mm->mmap_lock);
 112 }
 113
 114 static inline void mmap_read_lock(struct mm_struct *mm)
 115 {
 116         __mmap_lock_trace_start_locking(mm, false);
 117         down_read(&mm->mmap_lock);
 118         __mmap_lock_trace_acquire_returned(mm, false, true);
 119 }
 120
 121 static inline int mmap_read_lock_killable(struct mm_struct *mm)
 122 {
 123         int ret;
 124
 125         __mmap_lock_trace_start_locking(mm, false);
 126         ret = down_read_killable(&mm->mmap_lock);
 127         __mmap_lock_trace_acquire_returned(mm, false, ret == 0);
 128         return ret;
 129 }
 130
 131 static inline bool mmap_read_trylock(struct mm_struct *mm)
 132 {
 133         bool ret;
 134
 135         __mmap_lock_trace_start_locking(mm, false);
 136         ret = down_read_trylock(&mm->mmap_lock) != 0;
 137         __mmap_lock_trace_acquire_returned(mm, false, ret);
 138         return ret;
 139 }
 140
 141 static inline void mmap_read_unlock(struct mm_struct *mm)
 142 {
 143         __mmap_lock_trace_released(mm, false);
 144         up_read(&mm->mmap_lock);
 145 }
 146
 147 static inline bool mmap_read_trylock_non_owner(struct mm_struct *mm)
 148 {
 149         if (mmap_read_trylock(mm)) {
 150                 rwsem_release(&mm->mmap_lock.dep_map, _RET_IP_);
 151                 return true;
 152         }
 153         return false;
 154 }
 155
 156 static inline void mmap_read_unlock_non_owner(struct mm_struct *mm)
 157 {
 158         __mmap_lock_trace_released(mm, false);
 159         up_read_non_owner(&mm->mmap_lock);
 160 }
 161
 162 static inline void mmap_assert_locked(struct mm_struct *mm)
 163 {
 164         lockdep_assert_held(&mm->mmap_lock);
 165         VM_BUG_ON_MM(!rwsem_is_locked(&mm->mmap_lock), mm);
 166 }
 167
 168 static inline void mmap_assert_write_locked(struct mm_struct *mm)
 169 {
 170         lockdep_assert_held_write(&mm->mmap_lock);
 171         VM_BUG_ON_MM(!rwsem_is_locked(&mm->mmap_lock), mm);
 172 }
 173
 174 static inline int mmap_lock_is_contended(struct mm_struct *mm)
 175 {
 176         return rwsem_is_contended(&mm->mmap_lock);
 177 }
 178
 179 #endif /* _LINUX_MMAP_LOCK_H */