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1 : : #ifndef _LINUX_MM_TYPES_H
2 : : #define _LINUX_MM_TYPES_H
3 : :
4 : : #include <linux/auxvec.h>
5 : : #include <linux/types.h>
6 : : #include <linux/threads.h>
7 : : #include <linux/list.h>
8 : : #include <linux/spinlock.h>
9 : : #include <linux/rbtree.h>
10 : : #include <linux/rwsem.h>
11 : : #include <linux/completion.h>
12 : : #include <linux/cpumask.h>
13 : : #include <linux/page-debug-flags.h>
14 : : #include <linux/uprobes.h>
15 : : #include <linux/page-flags-layout.h>
16 : : #include <asm/page.h>
17 : : #include <asm/mmu.h>
18 : :
19 : : #ifndef AT_VECTOR_SIZE_ARCH
20 : : #define AT_VECTOR_SIZE_ARCH 0
21 : : #endif
22 : : #define AT_VECTOR_SIZE (2*(AT_VECTOR_SIZE_ARCH + AT_VECTOR_SIZE_BASE + 1))
23 : :
24 : : struct address_space;
25 : :
26 : : #define USE_SPLIT_PTE_PTLOCKS (NR_CPUS >= CONFIG_SPLIT_PTLOCK_CPUS)
27 : : #define USE_SPLIT_PMD_PTLOCKS (USE_SPLIT_PTE_PTLOCKS && \
28 : : IS_ENABLED(CONFIG_ARCH_ENABLE_SPLIT_PMD_PTLOCK))
29 : : #define ALLOC_SPLIT_PTLOCKS (SPINLOCK_SIZE > BITS_PER_LONG/8)
30 : :
31 : : /*
32 : : * Each physical page in the system has a struct page associated with
33 : : * it to keep track of whatever it is we are using the page for at the
34 : : * moment. Note that we have no way to track which tasks are using
35 : : * a page, though if it is a pagecache page, rmap structures can tell us
36 : : * who is mapping it.
37 : : *
38 : : * The objects in struct page are organized in double word blocks in
39 : : * order to allows us to use atomic double word operations on portions
40 : : * of struct page. That is currently only used by slub but the arrangement
41 : : * allows the use of atomic double word operations on the flags/mapping
42 : : * and lru list pointers also.
43 : : */
44 : : struct page {
45 : : /* First double word block */
46 : : unsigned long flags; /* Atomic flags, some possibly
47 : : * updated asynchronously */
48 : : union {
49 : : struct address_space *mapping; /* If low bit clear, points to
50 : : * inode address_space, or NULL.
51 : : * If page mapped as anonymous
52 : : * memory, low bit is set, and
53 : : * it points to anon_vma object:
54 : : * see PAGE_MAPPING_ANON below.
55 : : */
56 : : void *s_mem; /* slab first object */
57 : : };
58 : :
59 : : /* Second double word */
60 : : struct {
61 : : union {
62 : : pgoff_t index; /* Our offset within mapping. */
63 : : void *freelist; /* sl[aou]b first free object */
64 : : bool pfmemalloc; /* If set by the page allocator,
65 : : * ALLOC_NO_WATERMARKS was set
66 : : * and the low watermark was not
67 : : * met implying that the system
68 : : * is under some pressure. The
69 : : * caller should try ensure
70 : : * this page is only used to
71 : : * free other pages.
72 : : */
73 : : };
74 : :
75 : : union {
76 : : #if defined(CONFIG_HAVE_CMPXCHG_DOUBLE) && \
77 : : defined(CONFIG_HAVE_ALIGNED_STRUCT_PAGE)
78 : : /* Used for cmpxchg_double in slub */
79 : : unsigned long counters;
80 : : #else
81 : : /*
82 : : * Keep _count separate from slub cmpxchg_double data.
83 : : * As the rest of the double word is protected by
84 : : * slab_lock but _count is not.
85 : : */
86 : : unsigned counters;
87 : : #endif
88 : :
89 : : struct {
90 : :
91 : : union {
92 : : /*
93 : : * Count of ptes mapped in
94 : : * mms, to show when page is
95 : : * mapped & limit reverse map
96 : : * searches.
97 : : *
98 : : * Used also for tail pages
99 : : * refcounting instead of
100 : : * _count. Tail pages cannot
101 : : * be mapped and keeping the
102 : : * tail page _count zero at
103 : : * all times guarantees
104 : : * get_page_unless_zero() will
105 : : * never succeed on tail
106 : : * pages.
107 : : */
108 : : atomic_t _mapcount;
109 : :
110 : : struct { /* SLUB */
111 : : unsigned inuse:16;
112 : : unsigned objects:15;
113 : : unsigned frozen:1;
114 : : };
115 : : int units; /* SLOB */
116 : : };
117 : : atomic_t _count; /* Usage count, see below. */
118 : : };
119 : : unsigned int active; /* SLAB */
120 : : };
121 : : };
122 : :
123 : : /* Third double word block */
124 : : union {
125 : : struct list_head lru; /* Pageout list, eg. active_list
126 : : * protected by zone->lru_lock !
127 : : */
128 : : struct { /* slub per cpu partial pages */
129 : : struct page *next; /* Next partial slab */
130 : : #ifdef CONFIG_64BIT
131 : : int pages; /* Nr of partial slabs left */
132 : : int pobjects; /* Approximate # of objects */
133 : : #else
134 : : short int pages;
135 : : short int pobjects;
136 : : #endif
137 : : };
138 : :
139 : : struct list_head list; /* slobs list of pages */
140 : : struct slab *slab_page; /* slab fields */
141 : : struct rcu_head rcu_head; /* Used by SLAB
142 : : * when destroying via RCU
143 : : */
144 : : #if defined(CONFIG_TRANSPARENT_HUGEPAGE) && USE_SPLIT_PMD_PTLOCKS
145 : : pgtable_t pmd_huge_pte; /* protected by page->ptl */
146 : : #endif
147 : : };
148 : :
149 : : /* Remainder is not double word aligned */
150 : : union {
151 : : unsigned long private; /* Mapping-private opaque data:
152 : : * usually used for buffer_heads
153 : : * if PagePrivate set; used for
154 : : * swp_entry_t if PageSwapCache;
155 : : * indicates order in the buddy
156 : : * system if PG_buddy is set.
157 : : */
158 : : #if USE_SPLIT_PTE_PTLOCKS
159 : : #if ALLOC_SPLIT_PTLOCKS
160 : : spinlock_t *ptl;
161 : : #else
162 : : spinlock_t ptl;
163 : : #endif
164 : : #endif
165 : : struct kmem_cache *slab_cache; /* SL[AU]B: Pointer to slab */
166 : : struct page *first_page; /* Compound tail pages */
167 : : };
168 : :
169 : : /*
170 : : * On machines where all RAM is mapped into kernel address space,
171 : : * we can simply calculate the virtual address. On machines with
172 : : * highmem some memory is mapped into kernel virtual memory
173 : : * dynamically, so we need a place to store that address.
174 : : * Note that this field could be 16 bits on x86 ... ;)
175 : : *
176 : : * Architectures with slow multiplication can define
177 : : * WANT_PAGE_VIRTUAL in asm/page.h
178 : : */
179 : : #if defined(WANT_PAGE_VIRTUAL)
180 : : void *virtual; /* Kernel virtual address (NULL if
181 : : not kmapped, ie. highmem) */
182 : : #endif /* WANT_PAGE_VIRTUAL */
183 : : #ifdef CONFIG_WANT_PAGE_DEBUG_FLAGS
184 : : unsigned long debug_flags; /* Use atomic bitops on this */
185 : : #endif
186 : :
187 : : #ifdef CONFIG_KMEMCHECK
188 : : /*
189 : : * kmemcheck wants to track the status of each byte in a page; this
190 : : * is a pointer to such a status block. NULL if not tracked.
191 : : */
192 : : void *shadow;
193 : : #endif
194 : :
195 : : #ifdef LAST_CPUPID_NOT_IN_PAGE_FLAGS
196 : : int _last_cpupid;
197 : : #endif
198 : : }
199 : : /*
200 : : * The struct page can be forced to be double word aligned so that atomic ops
201 : : * on double words work. The SLUB allocator can make use of such a feature.
202 : : */
203 : : #ifdef CONFIG_HAVE_ALIGNED_STRUCT_PAGE
204 : : __aligned(2 * sizeof(unsigned long))
205 : : #endif
206 : : ;
207 : :
208 : : struct page_frag {
209 : : struct page *page;
210 : : #if (BITS_PER_LONG > 32) || (PAGE_SIZE >= 65536)
211 : : __u32 offset;
212 : : __u32 size;
213 : : #else
214 : : __u16 offset;
215 : : __u16 size;
216 : : #endif
217 : : };
218 : :
219 : : typedef unsigned long __nocast vm_flags_t;
220 : :
221 : : /*
222 : : * A region containing a mapping of a non-memory backed file under NOMMU
223 : : * conditions. These are held in a global tree and are pinned by the VMAs that
224 : : * map parts of them.
225 : : */
226 : : struct vm_region {
227 : : struct rb_node vm_rb; /* link in global region tree */
228 : : vm_flags_t vm_flags; /* VMA vm_flags */
229 : : unsigned long vm_start; /* start address of region */
230 : : unsigned long vm_end; /* region initialised to here */
231 : : unsigned long vm_top; /* region allocated to here */
232 : : unsigned long vm_pgoff; /* the offset in vm_file corresponding to vm_start */
233 : : struct file *vm_file; /* the backing file or NULL */
234 : :
235 : : int vm_usage; /* region usage count (access under nommu_region_sem) */
236 : : bool vm_icache_flushed : 1; /* true if the icache has been flushed for
237 : : * this region */
238 : : };
239 : :
240 : : /*
241 : : * This struct defines a memory VMM memory area. There is one of these
242 : : * per VM-area/task. A VM area is any part of the process virtual memory
243 : : * space that has a special rule for the page-fault handlers (ie a shared
244 : : * library, the executable area etc).
245 : : */
246 : : struct vm_area_struct {
247 : : /* The first cache line has the info for VMA tree walking. */
248 : :
249 : : unsigned long vm_start; /* Our start address within vm_mm. */
250 : : unsigned long vm_end; /* The first byte after our end address
251 : : within vm_mm. */
252 : :
253 : : /* linked list of VM areas per task, sorted by address */
254 : : struct vm_area_struct *vm_next, *vm_prev;
255 : :
256 : : struct rb_node vm_rb;
257 : :
258 : : /*
259 : : * Largest free memory gap in bytes to the left of this VMA.
260 : : * Either between this VMA and vma->vm_prev, or between one of the
261 : : * VMAs below us in the VMA rbtree and its ->vm_prev. This helps
262 : : * get_unmapped_area find a free area of the right size.
263 : : */
264 : : unsigned long rb_subtree_gap;
265 : :
266 : : /* Second cache line starts here. */
267 : :
268 : : struct mm_struct *vm_mm; /* The address space we belong to. */
269 : : pgprot_t vm_page_prot; /* Access permissions of this VMA. */
270 : : unsigned long vm_flags; /* Flags, see mm.h. */
271 : :
272 : : /*
273 : : * For areas with an address space and backing store,
274 : : * linkage into the address_space->i_mmap interval tree, or
275 : : * linkage of vma in the address_space->i_mmap_nonlinear list.
276 : : *
277 : : * For private anonymous mappings, a pointer to a null terminated string
278 : : * in the user process containing the name given to the vma, or NULL
279 : : * if unnamed.
280 : : */
281 : : union {
282 : : struct {
283 : : struct rb_node rb;
284 : : unsigned long rb_subtree_last;
285 : : } linear;
286 : : struct list_head nonlinear;
287 : : const char __user *anon_name;
288 : : } shared;
289 : :
290 : : /*
291 : : * A file's MAP_PRIVATE vma can be in both i_mmap tree and anon_vma
292 : : * list, after a COW of one of the file pages. A MAP_SHARED vma
293 : : * can only be in the i_mmap tree. An anonymous MAP_PRIVATE, stack
294 : : * or brk vma (with NULL file) can only be in an anon_vma list.
295 : : */
296 : : struct list_head anon_vma_chain; /* Serialized by mmap_sem &
297 : : * page_table_lock */
298 : : struct anon_vma *anon_vma; /* Serialized by page_table_lock */
299 : :
300 : : /* Function pointers to deal with this struct. */
301 : : const struct vm_operations_struct *vm_ops;
302 : :
303 : : /* Information about our backing store: */
304 : : unsigned long vm_pgoff; /* Offset (within vm_file) in PAGE_SIZE
305 : : units, *not* PAGE_CACHE_SIZE */
306 : : struct file * vm_file; /* File we map to (can be NULL). */
307 : : void * vm_private_data; /* was vm_pte (shared mem) */
308 : :
309 : : #ifndef CONFIG_MMU
310 : : struct vm_region *vm_region; /* NOMMU mapping region */
311 : : #endif
312 : : #ifdef CONFIG_NUMA
313 : : struct mempolicy *vm_policy; /* NUMA policy for the VMA */
314 : : #endif
315 : : };
316 : :
317 : : struct core_thread {
318 : : struct task_struct *task;
319 : : struct core_thread *next;
320 : : };
321 : :
322 : : struct core_state {
323 : : atomic_t nr_threads;
324 : : struct core_thread dumper;
325 : : struct completion startup;
326 : : };
327 : :
328 : : enum {
329 : : MM_FILEPAGES,
330 : : MM_ANONPAGES,
331 : : MM_SWAPENTS,
332 : : NR_MM_COUNTERS
333 : : };
334 : :
335 : : #if USE_SPLIT_PTE_PTLOCKS && defined(CONFIG_MMU)
336 : : #define SPLIT_RSS_COUNTING
337 : : /* per-thread cached information, */
338 : : struct task_rss_stat {
339 : : int events; /* for synchronization threshold */
340 : : int count[NR_MM_COUNTERS];
341 : : };
342 : : #endif /* USE_SPLIT_PTE_PTLOCKS */
343 : :
344 : : struct mm_rss_stat {
345 : : atomic_long_t count[NR_MM_COUNTERS];
346 : : };
347 : :
348 : : struct kioctx_table;
349 : : struct mm_struct {
350 : : struct vm_area_struct * mmap; /* list of VMAs */
351 : : struct rb_root mm_rb;
352 : : struct vm_area_struct * mmap_cache; /* last find_vma result */
353 : : #ifdef CONFIG_MMU
354 : : unsigned long (*get_unmapped_area) (struct file *filp,
355 : : unsigned long addr, unsigned long len,
356 : : unsigned long pgoff, unsigned long flags);
357 : : #endif
358 : : unsigned long mmap_base; /* base of mmap area */
359 : : unsigned long mmap_legacy_base; /* base of mmap area in bottom-up allocations */
360 : : unsigned long task_size; /* size of task vm space */
361 : : unsigned long highest_vm_end; /* highest vma end address */
362 : : pgd_t * pgd;
363 : : atomic_t mm_users; /* How many users with user space? */
364 : : atomic_t mm_count; /* How many references to "struct mm_struct" (users count as 1) */
365 : : atomic_long_t nr_ptes; /* Page table pages */
366 : : int map_count; /* number of VMAs */
367 : :
368 : : spinlock_t page_table_lock; /* Protects page tables and some counters */
369 : : struct rw_semaphore mmap_sem;
370 : :
371 : : struct list_head mmlist; /* List of maybe swapped mm's. These are globally strung
372 : : * together off init_mm.mmlist, and are protected
373 : : * by mmlist_lock
374 : : */
375 : :
376 : :
377 : : unsigned long hiwater_rss; /* High-watermark of RSS usage */
378 : : unsigned long hiwater_vm; /* High-water virtual memory usage */
379 : :
380 : : unsigned long total_vm; /* Total pages mapped */
381 : : unsigned long locked_vm; /* Pages that have PG_mlocked set */
382 : : unsigned long pinned_vm; /* Refcount permanently increased */
383 : : unsigned long shared_vm; /* Shared pages (files) */
384 : : unsigned long exec_vm; /* VM_EXEC & ~VM_WRITE */
385 : : unsigned long stack_vm; /* VM_GROWSUP/DOWN */
386 : : unsigned long def_flags;
387 : : unsigned long start_code, end_code, start_data, end_data;
388 : : unsigned long start_brk, brk, start_stack;
389 : : unsigned long arg_start, arg_end, env_start, env_end;
390 : :
391 : : unsigned long saved_auxv[AT_VECTOR_SIZE]; /* for /proc/PID/auxv */
392 : :
393 : : /*
394 : : * Special counters, in some configurations protected by the
395 : : * page_table_lock, in other configurations by being atomic.
396 : : */
397 : : struct mm_rss_stat rss_stat;
398 : :
399 : : struct linux_binfmt *binfmt;
400 : :
401 : : cpumask_var_t cpu_vm_mask_var;
402 : :
403 : : /* Architecture-specific MM context */
404 : : mm_context_t context;
405 : :
406 : : unsigned long flags; /* Must use atomic bitops to access the bits */
407 : :
408 : : struct core_state *core_state; /* coredumping support */
409 : : #ifdef CONFIG_AIO
410 : : spinlock_t ioctx_lock;
411 : : struct kioctx_table __rcu *ioctx_table;
412 : : #endif
413 : : #ifdef CONFIG_MM_OWNER
414 : : /*
415 : : * "owner" points to a task that is regarded as the canonical
416 : : * user/owner of this mm. All of the following must be true in
417 : : * order for it to be changed:
418 : : *
419 : : * current == mm->owner
420 : : * current->mm != mm
421 : : * new_owner->mm == mm
422 : : * new_owner->alloc_lock is held
423 : : */
424 : : struct task_struct __rcu *owner;
425 : : #endif
426 : :
427 : : /* store ref to file /proc/<pid>/exe symlink points to */
428 : : struct file *exe_file;
429 : : #ifdef CONFIG_MMU_NOTIFIER
430 : : struct mmu_notifier_mm *mmu_notifier_mm;
431 : : #endif
432 : : #if defined(CONFIG_TRANSPARENT_HUGEPAGE) && !USE_SPLIT_PMD_PTLOCKS
433 : : pgtable_t pmd_huge_pte; /* protected by page_table_lock */
434 : : #endif
435 : : #ifdef CONFIG_CPUMASK_OFFSTACK
436 : : struct cpumask cpumask_allocation;
437 : : #endif
438 : : #ifdef CONFIG_NUMA_BALANCING
439 : : /*
440 : : * numa_next_scan is the next time that the PTEs will be marked
441 : : * pte_numa. NUMA hinting faults will gather statistics and migrate
442 : : * pages to new nodes if necessary.
443 : : */
444 : : unsigned long numa_next_scan;
445 : :
446 : : /* Restart point for scanning and setting pte_numa */
447 : : unsigned long numa_scan_offset;
448 : :
449 : : /* numa_scan_seq prevents two threads setting pte_numa */
450 : : int numa_scan_seq;
451 : : #endif
452 : : #if defined(CONFIG_NUMA_BALANCING) || defined(CONFIG_COMPACTION)
453 : : /*
454 : : * An operation with batched TLB flushing is going on. Anything that
455 : : * can move process memory needs to flush the TLB when moving a
456 : : * PROT_NONE or PROT_NUMA mapped page.
457 : : */
458 : : bool tlb_flush_pending;
459 : : #endif
460 : : struct uprobes_state uprobes_state;
461 : : };
462 : :
463 : : static inline void mm_init_cpumask(struct mm_struct *mm)
464 : : {
465 : : #ifdef CONFIG_CPUMASK_OFFSTACK
466 : : mm->cpu_vm_mask_var = &mm->cpumask_allocation;
467 : : #endif
468 : : }
469 : :
470 : : /* Future-safe accessor for struct mm_struct's cpu_vm_mask. */
471 : : static inline cpumask_t *mm_cpumask(struct mm_struct *mm)
472 : : {
473 : : return mm->cpu_vm_mask_var;
474 : : }
475 : :
476 : : /* Return the name for an anonymous mapping or NULL for a file-backed mapping */
477 : : static inline const char __user *vma_get_anon_name(struct vm_area_struct *vma)
478 : : {
479 [ + + ][ + - ]: 1109926 : if (vma->vm_file)
[ # # ][ + + ]
[ + + ][ + + ]
480 : : return NULL;
481 : :
482 : : return vma->shared.anon_name;
483 : : }
484 : :
485 : : #if defined(CONFIG_NUMA_BALANCING) || defined(CONFIG_COMPACTION)
486 : : /*
487 : : * Memory barriers to keep this state in sync are graciously provided by
488 : : * the page table locks, outside of which no page table modifications happen.
489 : : * The barriers below prevent the compiler from re-ordering the instructions
490 : : * around the memory barriers that are already present in the code.
491 : : */
492 : : static inline bool mm_tlb_flush_pending(struct mm_struct *mm)
493 : : {
494 : : barrier();
495 : : return mm->tlb_flush_pending;
496 : : }
497 : : static inline void set_tlb_flush_pending(struct mm_struct *mm)
498 : : {
499 : 601094 : mm->tlb_flush_pending = true;
500 : :
501 : : /*
502 : : * Guarantee that the tlb_flush_pending store does not leak into the
503 : : * critical section updating the page tables
504 : : */
505 : 601094 : smp_mb__before_spinlock();
506 : : }
507 : : /* Clearing is done after a TLB flush, which also provides a barrier. */
508 : : static inline void clear_tlb_flush_pending(struct mm_struct *mm)
509 : : {
510 : 1797553 : barrier();
511 : 1797551 : mm->tlb_flush_pending = false;
512 : : }
513 : : #else
514 : : static inline bool mm_tlb_flush_pending(struct mm_struct *mm)
515 : : {
516 : : return false;
517 : : }
518 : : static inline void set_tlb_flush_pending(struct mm_struct *mm)
519 : : {
520 : : }
521 : : static inline void clear_tlb_flush_pending(struct mm_struct *mm)
522 : : {
523 : : }
524 : : #endif
525 : :
526 : : #endif /* _LINUX_MM_TYPES_H */
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