~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

TOMOYO Linux Cross Reference
Linux/include/linux/rmap.h

Version: ~ [ linux-5.4-rc7 ] ~ [ linux-5.3.10 ] ~ [ linux-5.2.21 ] ~ [ linux-5.1.21 ] ~ [ linux-5.0.21 ] ~ [ linux-4.20.17 ] ~ [ linux-4.19.83 ] ~ [ linux-4.18.20 ] ~ [ linux-4.17.19 ] ~ [ linux-4.16.18 ] ~ [ linux-4.15.18 ] ~ [ linux-4.14.153 ] ~ [ linux-4.13.16 ] ~ [ linux-4.12.14 ] ~ [ linux-4.11.12 ] ~ [ linux-4.10.17 ] ~ [ linux-4.9.200 ] ~ [ linux-4.8.17 ] ~ [ linux-4.7.10 ] ~ [ linux-4.6.7 ] ~ [ linux-4.5.7 ] ~ [ linux-4.4.200 ] ~ [ linux-4.3.6 ] ~ [ linux-4.2.8 ] ~ [ linux-4.1.52 ] ~ [ linux-4.0.9 ] ~ [ linux-3.19.8 ] ~ [ linux-3.18.140 ] ~ [ linux-3.17.8 ] ~ [ linux-3.16.76 ] ~ [ linux-3.15.10 ] ~ [ linux-3.14.79 ] ~ [ linux-3.13.11 ] ~ [ linux-3.12.74 ] ~ [ linux-3.11.10 ] ~ [ linux-3.10.108 ] ~ [ linux-3.9.11 ] ~ [ linux-3.8.13 ] ~ [ linux-3.7.10 ] ~ [ linux-3.6.11 ] ~ [ linux-3.5.7 ] ~ [ linux-3.4.113 ] ~ [ linux-3.3.8 ] ~ [ linux-3.2.102 ] ~ [ linux-3.1.10 ] ~ [ linux-3.0.101 ] ~ [ linux-2.6.32.71 ] ~ [ linux-2.6.0 ] ~ [ linux-2.4.37.11 ] ~ [ unix-v6-master ] ~ [ ccs-tools-1.8.5 ] ~ [ policy-sample ] ~
Architecture: ~ [ i386 ] ~ [ alpha ] ~ [ m68k ] ~ [ mips ] ~ [ ppc ] ~ [ sparc ] ~ [ sparc64 ] ~

  1 #ifndef _LINUX_RMAP_H
  2 #define _LINUX_RMAP_H
  3 /*
  4  * Declarations for Reverse Mapping functions in mm/rmap.c
  5  */
  6 
  7 #include <linux/list.h>
  8 #include <linux/slab.h>
  9 #include <linux/mm.h>
 10 #include <linux/rwsem.h>
 11 #include <linux/memcontrol.h>
 12 
 13 /*
 14  * The anon_vma heads a list of private "related" vmas, to scan if
 15  * an anonymous page pointing to this anon_vma needs to be unmapped:
 16  * the vmas on the list will be related by forking, or by splitting.
 17  *
 18  * Since vmas come and go as they are split and merged (particularly
 19  * in mprotect), the mapping field of an anonymous page cannot point
 20  * directly to a vma: instead it points to an anon_vma, on whose list
 21  * the related vmas can be easily linked or unlinked.
 22  *
 23  * After unlinking the last vma on the list, we must garbage collect
 24  * the anon_vma object itself: we're guaranteed no page can be
 25  * pointing to this anon_vma once its vma list is empty.
 26  */
 27 struct anon_vma {
 28         struct anon_vma *root;          /* Root of this anon_vma tree */
 29         struct rw_semaphore rwsem;      /* W: modification, R: walking the list */
 30         /*
 31          * The refcount is taken on an anon_vma when there is no
 32          * guarantee that the vma of page tables will exist for
 33          * the duration of the operation. A caller that takes
 34          * the reference is responsible for clearing up the
 35          * anon_vma if they are the last user on release
 36          */
 37         atomic_t refcount;
 38 
 39         /*
 40          * Count of child anon_vmas and VMAs which points to this anon_vma.
 41          *
 42          * This counter is used for making decision about reusing anon_vma
 43          * instead of forking new one. See comments in function anon_vma_clone.
 44          */
 45         unsigned degree;
 46 
 47         struct anon_vma *parent;        /* Parent of this anon_vma */
 48 
 49         /*
 50          * NOTE: the LSB of the rb_root.rb_node is set by
 51          * mm_take_all_locks() _after_ taking the above lock. So the
 52          * rb_root must only be read/written after taking the above lock
 53          * to be sure to see a valid next pointer. The LSB bit itself
 54          * is serialized by a system wide lock only visible to
 55          * mm_take_all_locks() (mm_all_locks_mutex).
 56          */
 57         struct rb_root rb_root; /* Interval tree of private "related" vmas */
 58 };
 59 
 60 /*
 61  * The copy-on-write semantics of fork mean that an anon_vma
 62  * can become associated with multiple processes. Furthermore,
 63  * each child process will have its own anon_vma, where new
 64  * pages for that process are instantiated.
 65  *
 66  * This structure allows us to find the anon_vmas associated
 67  * with a VMA, or the VMAs associated with an anon_vma.
 68  * The "same_vma" list contains the anon_vma_chains linking
 69  * all the anon_vmas associated with this VMA.
 70  * The "rb" field indexes on an interval tree the anon_vma_chains
 71  * which link all the VMAs associated with this anon_vma.
 72  */
 73 struct anon_vma_chain {
 74         struct vm_area_struct *vma;
 75         struct anon_vma *anon_vma;
 76         struct list_head same_vma;   /* locked by mmap_sem & page_table_lock */
 77         struct rb_node rb;                      /* locked by anon_vma->rwsem */
 78         unsigned long rb_subtree_last;
 79 #ifdef CONFIG_DEBUG_VM_RB
 80         unsigned long cached_vma_start, cached_vma_last;
 81 #endif
 82 };
 83 
 84 enum ttu_flags {
 85         TTU_UNMAP = 1,                  /* unmap mode */
 86         TTU_MIGRATION = 2,              /* migration mode */
 87         TTU_MUNLOCK = 4,                /* munlock mode */
 88 
 89         TTU_IGNORE_MLOCK = (1 << 8),    /* ignore mlock */
 90         TTU_IGNORE_ACCESS = (1 << 9),   /* don't age */
 91         TTU_IGNORE_HWPOISON = (1 << 10),/* corrupted page is recoverable */
 92 };
 93 
 94 #ifdef CONFIG_MMU
 95 static inline void get_anon_vma(struct anon_vma *anon_vma)
 96 {
 97         atomic_inc(&anon_vma->refcount);
 98 }
 99 
100 void __put_anon_vma(struct anon_vma *anon_vma);
101 
102 static inline void put_anon_vma(struct anon_vma *anon_vma)
103 {
104         if (atomic_dec_and_test(&anon_vma->refcount))
105                 __put_anon_vma(anon_vma);
106 }
107 
108 static inline void anon_vma_lock_write(struct anon_vma *anon_vma)
109 {
110         down_write(&anon_vma->root->rwsem);
111 }
112 
113 static inline void anon_vma_unlock_write(struct anon_vma *anon_vma)
114 {
115         up_write(&anon_vma->root->rwsem);
116 }
117 
118 static inline void anon_vma_lock_read(struct anon_vma *anon_vma)
119 {
120         down_read(&anon_vma->root->rwsem);
121 }
122 
123 static inline void anon_vma_unlock_read(struct anon_vma *anon_vma)
124 {
125         up_read(&anon_vma->root->rwsem);
126 }
127 
128 
129 /*
130  * anon_vma helper functions.
131  */
132 void anon_vma_init(void);       /* create anon_vma_cachep */
133 int  anon_vma_prepare(struct vm_area_struct *);
134 void unlink_anon_vmas(struct vm_area_struct *);
135 int anon_vma_clone(struct vm_area_struct *, struct vm_area_struct *);
136 int anon_vma_fork(struct vm_area_struct *, struct vm_area_struct *);
137 
138 static inline void anon_vma_merge(struct vm_area_struct *vma,
139                                   struct vm_area_struct *next)
140 {
141         VM_BUG_ON_VMA(vma->anon_vma != next->anon_vma, vma);
142         unlink_anon_vmas(next);
143 }
144 
145 struct anon_vma *page_get_anon_vma(struct page *page);
146 
147 /*
148  * rmap interfaces called when adding or removing pte of page
149  */
150 void page_move_anon_rmap(struct page *, struct vm_area_struct *, unsigned long);
151 void page_add_anon_rmap(struct page *, struct vm_area_struct *, unsigned long);
152 void do_page_add_anon_rmap(struct page *, struct vm_area_struct *,
153                            unsigned long, int);
154 void page_add_new_anon_rmap(struct page *, struct vm_area_struct *, unsigned long);
155 void page_add_file_rmap(struct page *);
156 void page_remove_rmap(struct page *);
157 
158 void hugepage_add_anon_rmap(struct page *, struct vm_area_struct *,
159                             unsigned long);
160 void hugepage_add_new_anon_rmap(struct page *, struct vm_area_struct *,
161                                 unsigned long);
162 
163 static inline void page_dup_rmap(struct page *page)
164 {
165         atomic_inc(&page->_mapcount);
166 }
167 
168 /*
169  * Called from mm/vmscan.c to handle paging out
170  */
171 int page_referenced(struct page *, int is_locked,
172                         struct mem_cgroup *memcg, unsigned long *vm_flags);
173 
174 #define TTU_ACTION(x) ((x) & TTU_ACTION_MASK)
175 
176 int try_to_unmap(struct page *, enum ttu_flags flags);
177 
178 /*
179  * Used by uprobes to replace a userspace page safely
180  */
181 pte_t *__page_check_address(struct page *, struct mm_struct *,
182                                 unsigned long, spinlock_t **, int);
183 
184 static inline pte_t *page_check_address(struct page *page, struct mm_struct *mm,
185                                         unsigned long address,
186                                         spinlock_t **ptlp, int sync)
187 {
188         pte_t *ptep;
189 
190         __cond_lock(*ptlp, ptep = __page_check_address(page, mm, address,
191                                                        ptlp, sync));
192         return ptep;
193 }
194 
195 /*
196  * Used by swapoff to help locate where page is expected in vma.
197  */
198 unsigned long page_address_in_vma(struct page *, struct vm_area_struct *);
199 
200 /*
201  * Cleans the PTEs of shared mappings.
202  * (and since clean PTEs should also be readonly, write protects them too)
203  *
204  * returns the number of cleaned PTEs.
205  */
206 int page_mkclean(struct page *);
207 
208 /*
209  * called in munlock()/munmap() path to check for other vmas holding
210  * the page mlocked.
211  */
212 int try_to_munlock(struct page *);
213 
214 /*
215  * Called by memory-failure.c to kill processes.
216  */
217 struct anon_vma *page_lock_anon_vma_read(struct page *page);
218 void page_unlock_anon_vma_read(struct anon_vma *anon_vma);
219 int page_mapped_in_vma(struct page *page, struct vm_area_struct *vma);
220 
221 /*
222  * rmap_walk_control: To control rmap traversing for specific needs
223  *
224  * arg: passed to rmap_one() and invalid_vma()
225  * rmap_one: executed on each vma where page is mapped
226  * done: for checking traversing termination condition
227  * anon_lock: for getting anon_lock by optimized way rather than default
228  * invalid_vma: for skipping uninterested vma
229  */
230 struct rmap_walk_control {
231         void *arg;
232         int (*rmap_one)(struct page *page, struct vm_area_struct *vma,
233                                         unsigned long addr, void *arg);
234         int (*done)(struct page *page);
235         struct anon_vma *(*anon_lock)(struct page *page);
236         bool (*invalid_vma)(struct vm_area_struct *vma, void *arg);
237 };
238 
239 int rmap_walk(struct page *page, struct rmap_walk_control *rwc);
240 
241 #else   /* !CONFIG_MMU */
242 
243 #define anon_vma_init()         do {} while (0)
244 #define anon_vma_prepare(vma)   (0)
245 #define anon_vma_link(vma)      do {} while (0)
246 
247 static inline int page_referenced(struct page *page, int is_locked,
248                                   struct mem_cgroup *memcg,
249                                   unsigned long *vm_flags)
250 {
251         *vm_flags = 0;
252         return 0;
253 }
254 
255 #define try_to_unmap(page, refs) SWAP_FAIL
256 
257 static inline int page_mkclean(struct page *page)
258 {
259         return 0;
260 }
261 
262 
263 #endif  /* CONFIG_MMU */
264 
265 /*
266  * Return values of try_to_unmap
267  */
268 #define SWAP_SUCCESS    0
269 #define SWAP_AGAIN      1
270 #define SWAP_FAIL       2
271 #define SWAP_MLOCK      3
272 
273 #endif  /* _LINUX_RMAP_H */
274 

~ [ source navigation ] ~ [ diff markup ] ~ [ identifier search ] ~

kernel.org | git.kernel.org | LWN.net | Project Home | Wiki (Japanese) | Wiki (English) | SVN repository | Mail admin

Linux® is a registered trademark of Linus Torvalds in the United States and other countries.
TOMOYO® is a registered trademark of NTT DATA CORPORATION.

osdn.jp