| 1 | /* SPDX-License-Identifier: GPL-2.0 */ |
| 2 | #ifndef _LINUX_MM_TYPES_H |
| 3 | #define _LINUX_MM_TYPES_H |
| 4 | |
| 5 | #include <linux/mm_types_task.h> |
| 6 | |
| 7 | #include <linux/auxvec.h> |
| 8 | #include <linux/kref.h> |
| 9 | #include <linux/list.h> |
| 10 | #include <linux/spinlock.h> |
| 11 | #include <linux/rbtree.h> |
| 12 | #include <linux/maple_tree.h> |
| 13 | #include <linux/rwsem.h> |
| 14 | #include <linux/completion.h> |
| 15 | #include <linux/cpumask.h> |
| 16 | #include <linux/uprobes.h> |
| 17 | #include <linux/rcupdate.h> |
| 18 | #include <linux/page-flags-layout.h> |
| 19 | #include <linux/workqueue.h> |
| 20 | #include <linux/seqlock.h> |
| 21 | #include <linux/percpu_counter.h> |
| 22 | |
| 23 | #include <asm/mmu.h> |
| 24 | |
| 25 | #ifndef AT_VECTOR_SIZE_ARCH |
| 26 | #define AT_VECTOR_SIZE_ARCH 0 |
| 27 | #endif |
| 28 | #define AT_VECTOR_SIZE (2*(AT_VECTOR_SIZE_ARCH + AT_VECTOR_SIZE_BASE + 1)) |
| 29 | |
| 30 | #define INIT_PASID 0 |
| 31 | |
| 32 | struct address_space; |
| 33 | struct mem_cgroup; |
| 34 | |
| 35 | /* |
| 36 | * Each physical page in the system has a struct page associated with |
| 37 | * it to keep track of whatever it is we are using the page for at the |
| 38 | * moment. Note that we have no way to track which tasks are using |
| 39 | * a page, though if it is a pagecache page, rmap structures can tell us |
| 40 | * who is mapping it. |
| 41 | * |
| 42 | * If you allocate the page using alloc_pages(), you can use some of the |
| 43 | * space in struct page for your own purposes. The five words in the main |
| 44 | * union are available, except for bit 0 of the first word which must be |
| 45 | * kept clear. Many users use this word to store a pointer to an object |
| 46 | * which is guaranteed to be aligned. If you use the same storage as |
| 47 | * page->mapping, you must restore it to NULL before freeing the page. |
| 48 | * |
| 49 | * If your page will not be mapped to userspace, you can also use the four |
| 50 | * bytes in the mapcount union, but you must call page_mapcount_reset() |
| 51 | * before freeing it. |
| 52 | * |
| 53 | * If you want to use the refcount field, it must be used in such a way |
| 54 | * that other CPUs temporarily incrementing and then decrementing the |
| 55 | * refcount does not cause problems. On receiving the page from |
| 56 | * alloc_pages(), the refcount will be positive. |
| 57 | * |
| 58 | * If you allocate pages of order > 0, you can use some of the fields |
| 59 | * in each subpage, but you may need to restore some of their values |
| 60 | * afterwards. |
| 61 | * |
| 62 | * SLUB uses cmpxchg_double() to atomically update its freelist and counters. |
| 63 | * That requires that freelist & counters in struct slab be adjacent and |
| 64 | * double-word aligned. Because struct slab currently just reinterprets the |
| 65 | * bits of struct page, we align all struct pages to double-word boundaries, |
| 66 | * and ensure that 'freelist' is aligned within struct slab. |
| 67 | */ |
| 68 | #ifdef CONFIG_HAVE_ALIGNED_STRUCT_PAGE |
| 69 | #define _struct_page_alignment __aligned(2 * sizeof(unsigned long)) |
| 70 | #else |
| 71 | #define _struct_page_alignment __aligned(sizeof(unsigned long)) |
| 72 | #endif |
| 73 | |
| 74 | struct page { |
| 75 | unsigned long flags; /* Atomic flags, some possibly |
| 76 | * updated asynchronously */ |
| 77 | /* |
| 78 | * Five words (20/40 bytes) are available in this union. |
| 79 | * WARNING: bit 0 of the first word is used for PageTail(). That |
| 80 | * means the other users of this union MUST NOT use the bit to |
| 81 | * avoid collision and false-positive PageTail(). |
| 82 | */ |
| 83 | union { |
| 84 | struct { /* Page cache and anonymous pages */ |
| 85 | /** |
| 86 | * @lru: Pageout list, eg. active_list protected by |
| 87 | * lruvec->lru_lock. Sometimes used as a generic list |
| 88 | * by the page owner. |
| 89 | */ |
| 90 | union { |
| 91 | struct list_head lru; |
| 92 | |
| 93 | /* Or, for the Unevictable "LRU list" slot */ |
| 94 | struct { |
| 95 | /* Always even, to negate PageTail */ |
| 96 | void *__filler; |
| 97 | /* Count page's or folio's mlocks */ |
| 98 | unsigned int mlock_count; |
| 99 | }; |
| 100 | |
| 101 | /* Or, free page */ |
| 102 | struct list_head buddy_list; |
| 103 | struct list_head pcp_list; |
| 104 | }; |
| 105 | /* See page-flags.h for PAGE_MAPPING_FLAGS */ |
| 106 | struct address_space *mapping; |
| 107 | union { |
| 108 | pgoff_t index; /* Our offset within mapping. */ |
| 109 | unsigned long share; /* share count for fsdax */ |
| 110 | }; |
| 111 | /** |
| 112 | * @private: Mapping-private opaque data. |
| 113 | * Usually used for buffer_heads if PagePrivate. |
| 114 | * Used for swp_entry_t if PageSwapCache. |
| 115 | * Indicates order in the buddy system if PageBuddy. |
| 116 | */ |
| 117 | unsigned long private; |
| 118 | }; |
| 119 | struct { /* page_pool used by netstack */ |
| 120 | /** |
| 121 | * @pp_magic: magic value to avoid recycling non |
| 122 | * page_pool allocated pages. |
| 123 | */ |
| 124 | unsigned long pp_magic; |
| 125 | struct page_pool *pp; |
| 126 | unsigned long _pp_mapping_pad; |
| 127 | unsigned long dma_addr; |
| 128 | union { |
| 129 | /** |
| 130 | * dma_addr_upper: might require a 64-bit |
| 131 | * value on 32-bit architectures. |
| 132 | */ |
| 133 | unsigned long dma_addr_upper; |
| 134 | /** |
| 135 | * For frag page support, not supported in |
| 136 | * 32-bit architectures with 64-bit DMA. |
| 137 | */ |
| 138 | atomic_long_t pp_frag_count; |
| 139 | }; |
| 140 | }; |
| 141 | struct { /* Tail pages of compound page */ |
| 142 | unsigned long compound_head; /* Bit zero is set */ |
| 143 | }; |
| 144 | struct { /* Page table pages */ |
| 145 | unsigned long _pt_pad_1; /* compound_head */ |
| 146 | pgtable_t pmd_huge_pte; /* protected by page->ptl */ |
| 147 | unsigned long _pt_pad_2; /* mapping */ |
| 148 | union { |
| 149 | struct mm_struct *pt_mm; /* x86 pgds only */ |
| 150 | atomic_t pt_frag_refcount; /* powerpc */ |
| 151 | }; |
| 152 | #if ALLOC_SPLIT_PTLOCKS |
| 153 | spinlock_t *ptl; |
| 154 | #else |
| 155 | spinlock_t ptl; |
| 156 | #endif |
| 157 | }; |
| 158 | struct { /* ZONE_DEVICE pages */ |
| 159 | /** @pgmap: Points to the hosting device page map. */ |
| 160 | struct dev_pagemap *pgmap; |
| 161 | void *zone_device_data; |
| 162 | /* |
| 163 | * ZONE_DEVICE private pages are counted as being |
| 164 | * mapped so the next 3 words hold the mapping, index, |
| 165 | * and private fields from the source anonymous or |
| 166 | * page cache page while the page is migrated to device |
| 167 | * private memory. |
| 168 | * ZONE_DEVICE MEMORY_DEVICE_FS_DAX pages also |
| 169 | * use the mapping, index, and private fields when |
| 170 | * pmem backed DAX files are mapped. |
| 171 | */ |
| 172 | }; |
| 173 | |
| 174 | /** @rcu_head: You can use this to free a page by RCU. */ |
| 175 | struct rcu_head rcu_head; |
| 176 | }; |
| 177 | |
| 178 | union { /* This union is 4 bytes in size. */ |
| 179 | /* |
| 180 | * If the page can be mapped to userspace, encodes the number |
| 181 | * of times this page is referenced by a page table. |
| 182 | */ |
| 183 | atomic_t _mapcount; |
| 184 | |
| 185 | /* |
| 186 | * If the page is neither PageSlab nor mappable to userspace, |
| 187 | * the value stored here may help determine what this page |
| 188 | * is used for. See page-flags.h for a list of page types |
| 189 | * which are currently stored here. |
| 190 | */ |
| 191 | unsigned int page_type; |
| 192 | }; |
| 193 | |
| 194 | /* Usage count. *DO NOT USE DIRECTLY*. See page_ref.h */ |
| 195 | atomic_t _refcount; |
| 196 | |
| 197 | #ifdef CONFIG_MEMCG |
| 198 | unsigned long memcg_data; |
| 199 | #endif |
| 200 | |
| 201 | /* |
| 202 | * On machines where all RAM is mapped into kernel address space, |
| 203 | * we can simply calculate the virtual address. On machines with |
| 204 | * highmem some memory is mapped into kernel virtual memory |
| 205 | * dynamically, so we need a place to store that address. |
| 206 | * Note that this field could be 16 bits on x86 ... ;) |
| 207 | * |
| 208 | * Architectures with slow multiplication can define |
| 209 | * WANT_PAGE_VIRTUAL in asm/page.h |
| 210 | */ |
| 211 | #if defined(WANT_PAGE_VIRTUAL) |
| 212 | void *virtual; /* Kernel virtual address (NULL if |
| 213 | not kmapped, ie. highmem) */ |
| 214 | #endif /* WANT_PAGE_VIRTUAL */ |
| 215 | |
| 216 | #ifdef CONFIG_KMSAN |
| 217 | /* |
| 218 | * KMSAN metadata for this page: |
| 219 | * - shadow page: every bit indicates whether the corresponding |
| 220 | * bit of the original page is initialized (0) or not (1); |
| 221 | * - origin page: every 4 bytes contain an id of the stack trace |
| 222 | * where the uninitialized value was created. |
| 223 | */ |
| 224 | struct page *kmsan_shadow; |
| 225 | struct page *kmsan_origin; |
| 226 | #endif |
| 227 | |
| 228 | #ifdef LAST_CPUPID_NOT_IN_PAGE_FLAGS |
| 229 | int _last_cpupid; |
| 230 | #endif |
| 231 | } _struct_page_alignment; |
| 232 | |
| 233 | /* |
| 234 | * struct encoded_page - a nonexistent type marking this pointer |
| 235 | * |
| 236 | * An 'encoded_page' pointer is a pointer to a regular 'struct page', but |
| 237 | * with the low bits of the pointer indicating extra context-dependent |
| 238 | * information. Not super-common, but happens in mmu_gather and mlock |
| 239 | * handling, and this acts as a type system check on that use. |
| 240 | * |
| 241 | * We only really have two guaranteed bits in general, although you could |
| 242 | * play with 'struct page' alignment (see CONFIG_HAVE_ALIGNED_STRUCT_PAGE) |
| 243 | * for more. |
| 244 | * |
| 245 | * Use the supplied helper functions to endcode/decode the pointer and bits. |
| 246 | */ |
| 247 | struct encoded_page; |
| 248 | #define ENCODE_PAGE_BITS 3ul |
| 249 | static __always_inline struct encoded_page *encode_page(struct page *page, unsigned long flags) |
| 250 | { |
| 251 | BUILD_BUG_ON(flags > ENCODE_PAGE_BITS); |
| 252 | return (struct encoded_page *)(flags | (unsigned long)page); |
| 253 | } |
| 254 | |
| 255 | static inline unsigned long encoded_page_flags(struct encoded_page *page) |
| 256 | { |
| 257 | return ENCODE_PAGE_BITS & (unsigned long)page; |
| 258 | } |
| 259 | |
| 260 | static inline struct page *encoded_page_ptr(struct encoded_page *page) |
| 261 | { |
| 262 | return (struct page *)(~ENCODE_PAGE_BITS & (unsigned long)page); |
| 263 | } |
| 264 | |
| 265 | /** |
| 266 | * struct folio - Represents a contiguous set of bytes. |
| 267 | * @flags: Identical to the page flags. |
| 268 | * @lru: Least Recently Used list; tracks how recently this folio was used. |
| 269 | * @mlock_count: Number of times this folio has been pinned by mlock(). |
| 270 | * @mapping: The file this page belongs to, or refers to the anon_vma for |
| 271 | * anonymous memory. |
| 272 | * @index: Offset within the file, in units of pages. For anonymous memory, |
| 273 | * this is the index from the beginning of the mmap. |
| 274 | * @private: Filesystem per-folio data (see folio_attach_private()). |
| 275 | * Used for swp_entry_t if folio_test_swapcache(). |
| 276 | * @_mapcount: Do not access this member directly. Use folio_mapcount() to |
| 277 | * find out how many times this folio is mapped by userspace. |
| 278 | * @_refcount: Do not access this member directly. Use folio_ref_count() |
| 279 | * to find how many references there are to this folio. |
| 280 | * @memcg_data: Memory Control Group data. |
| 281 | * @_folio_dtor: Which destructor to use for this folio. |
| 282 | * @_folio_order: Do not use directly, call folio_order(). |
| 283 | * @_entire_mapcount: Do not use directly, call folio_entire_mapcount(). |
| 284 | * @_nr_pages_mapped: Do not use directly, call folio_mapcount(). |
| 285 | * @_pincount: Do not use directly, call folio_maybe_dma_pinned(). |
| 286 | * @_folio_nr_pages: Do not use directly, call folio_nr_pages(). |
| 287 | * @_hugetlb_subpool: Do not use directly, use accessor in hugetlb.h. |
| 288 | * @_hugetlb_cgroup: Do not use directly, use accessor in hugetlb_cgroup.h. |
| 289 | * @_hugetlb_cgroup_rsvd: Do not use directly, use accessor in hugetlb_cgroup.h. |
| 290 | * @_hugetlb_hwpoison: Do not use directly, call raw_hwp_list_head(). |
| 291 | * @_deferred_list: Folios to be split under memory pressure. |
| 292 | * |
| 293 | * A folio is a physically, virtually and logically contiguous set |
| 294 | * of bytes. It is a power-of-two in size, and it is aligned to that |
| 295 | * same power-of-two. It is at least as large as %PAGE_SIZE. If it is |
| 296 | * in the page cache, it is at a file offset which is a multiple of that |
| 297 | * power-of-two. It may be mapped into userspace at an address which is |
| 298 | * at an arbitrary page offset, but its kernel virtual address is aligned |
| 299 | * to its size. |
| 300 | */ |
| 301 | struct folio { |
| 302 | /* private: don't document the anon union */ |
| 303 | union { |
| 304 | struct { |
| 305 | /* public: */ |
| 306 | unsigned long flags; |
| 307 | union { |
| 308 | struct list_head lru; |
| 309 | /* private: avoid cluttering the output */ |
| 310 | struct { |
| 311 | void *__filler; |
| 312 | /* public: */ |
| 313 | unsigned int mlock_count; |
| 314 | /* private: */ |
| 315 | }; |
| 316 | /* public: */ |
| 317 | }; |
| 318 | struct address_space *mapping; |
| 319 | pgoff_t index; |
| 320 | void *private; |
| 321 | atomic_t _mapcount; |
| 322 | atomic_t _refcount; |
| 323 | #ifdef CONFIG_MEMCG |
| 324 | unsigned long memcg_data; |
| 325 | #endif |
| 326 | /* private: the union with struct page is transitional */ |
| 327 | }; |
| 328 | struct page page; |
| 329 | }; |
| 330 | union { |
| 331 | struct { |
| 332 | unsigned long _flags_1; |
| 333 | unsigned long _head_1; |
| 334 | /* public: */ |
| 335 | unsigned char _folio_dtor; |
| 336 | unsigned char _folio_order; |
| 337 | atomic_t _entire_mapcount; |
| 338 | atomic_t _nr_pages_mapped; |
| 339 | atomic_t _pincount; |
| 340 | #ifdef CONFIG_64BIT |
| 341 | unsigned int _folio_nr_pages; |
| 342 | #endif |
| 343 | /* private: the union with struct page is transitional */ |
| 344 | }; |
| 345 | struct page __page_1; |
| 346 | }; |
| 347 | union { |
| 348 | struct { |
| 349 | unsigned long _flags_2; |
| 350 | unsigned long _head_2; |
| 351 | /* public: */ |
| 352 | void *_hugetlb_subpool; |
| 353 | void *_hugetlb_cgroup; |
| 354 | void *_hugetlb_cgroup_rsvd; |
| 355 | void *_hugetlb_hwpoison; |
| 356 | /* private: the union with struct page is transitional */ |
| 357 | }; |
| 358 | struct { |
| 359 | unsigned long _flags_2a; |
| 360 | unsigned long _head_2a; |
| 361 | /* public: */ |
| 362 | struct list_head _deferred_list; |
| 363 | /* private: the union with struct page is transitional */ |
| 364 | }; |
| 365 | struct page __page_2; |
| 366 | }; |
| 367 | }; |
| 368 | |
| 369 | #define FOLIO_MATCH(pg, fl) \ |
| 370 | static_assert(offsetof(struct page, pg) == offsetof(struct folio, fl)) |
| 371 | FOLIO_MATCH(flags, flags); |
| 372 | FOLIO_MATCH(lru, lru); |
| 373 | FOLIO_MATCH(mapping, mapping); |
| 374 | FOLIO_MATCH(compound_head, lru); |
| 375 | FOLIO_MATCH(index, index); |
| 376 | FOLIO_MATCH(private, private); |
| 377 | FOLIO_MATCH(_mapcount, _mapcount); |
| 378 | FOLIO_MATCH(_refcount, _refcount); |
| 379 | #ifdef CONFIG_MEMCG |
| 380 | FOLIO_MATCH(memcg_data, memcg_data); |
| 381 | #endif |
| 382 | #undef FOLIO_MATCH |
| 383 | #define FOLIO_MATCH(pg, fl) \ |
| 384 | static_assert(offsetof(struct folio, fl) == \ |
| 385 | offsetof(struct page, pg) + sizeof(struct page)) |
| 386 | FOLIO_MATCH(flags, _flags_1); |
| 387 | FOLIO_MATCH(compound_head, _head_1); |
| 388 | #undef FOLIO_MATCH |
| 389 | #define FOLIO_MATCH(pg, fl) \ |
| 390 | static_assert(offsetof(struct folio, fl) == \ |
| 391 | offsetof(struct page, pg) + 2 * sizeof(struct page)) |
| 392 | FOLIO_MATCH(flags, _flags_2); |
| 393 | FOLIO_MATCH(compound_head, _head_2); |
| 394 | #undef FOLIO_MATCH |
| 395 | |
| 396 | /* |
| 397 | * Used for sizing the vmemmap region on some architectures |
| 398 | */ |
| 399 | #define STRUCT_PAGE_MAX_SHIFT (order_base_2(sizeof(struct page))) |
| 400 | |
| 401 | #define PAGE_FRAG_CACHE_MAX_SIZE __ALIGN_MASK(32768, ~PAGE_MASK) |
| 402 | #define PAGE_FRAG_CACHE_MAX_ORDER get_order(PAGE_FRAG_CACHE_MAX_SIZE) |
| 403 | |
| 404 | /* |
| 405 | * page_private can be used on tail pages. However, PagePrivate is only |
| 406 | * checked by the VM on the head page. So page_private on the tail pages |
| 407 | * should be used for data that's ancillary to the head page (eg attaching |
| 408 | * buffer heads to tail pages after attaching buffer heads to the head page) |
| 409 | */ |
| 410 | #define page_private(page) ((page)->private) |
| 411 | |
| 412 | static inline void set_page_private(struct page *page, unsigned long private) |
| 413 | { |
| 414 | page->private = private; |
| 415 | } |
| 416 | |
| 417 | static inline void *folio_get_private(struct folio *folio) |
| 418 | { |
| 419 | return folio->private; |
| 420 | } |
| 421 | |
| 422 | struct page_frag_cache { |
| 423 | void * va; |
| 424 | #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE) |
| 425 | __u16 offset; |
| 426 | __u16 size; |
| 427 | #else |
| 428 | __u32 offset; |
| 429 | #endif |
| 430 | /* we maintain a pagecount bias, so that we dont dirty cache line |
| 431 | * containing page->_refcount every time we allocate a fragment. |
| 432 | */ |
| 433 | unsigned int pagecnt_bias; |
| 434 | bool pfmemalloc; |
| 435 | }; |
| 436 | |
| 437 | typedef unsigned long vm_flags_t; |
| 438 | |
| 439 | /* |
| 440 | * A region containing a mapping of a non-memory backed file under NOMMU |
| 441 | * conditions. These are held in a global tree and are pinned by the VMAs that |
| 442 | * map parts of them. |
| 443 | */ |
| 444 | struct vm_region { |
| 445 | struct rb_node vm_rb; /* link in global region tree */ |
| 446 | vm_flags_t vm_flags; /* VMA vm_flags */ |
| 447 | unsigned long vm_start; /* start address of region */ |
| 448 | unsigned long vm_end; /* region initialised to here */ |
| 449 | unsigned long vm_top; /* region allocated to here */ |
| 450 | unsigned long vm_pgoff; /* the offset in vm_file corresponding to vm_start */ |
| 451 | struct file *vm_file; /* the backing file or NULL */ |
| 452 | |
| 453 | int vm_usage; /* region usage count (access under nommu_region_sem) */ |
| 454 | bool vm_icache_flushed : 1; /* true if the icache has been flushed for |
| 455 | * this region */ |
| 456 | }; |
| 457 | |
| 458 | #ifdef CONFIG_USERFAULTFD |
| 459 | #define NULL_VM_UFFD_CTX ((struct vm_userfaultfd_ctx) { NULL, }) |
| 460 | struct vm_userfaultfd_ctx { |
| 461 | struct userfaultfd_ctx *ctx; |
| 462 | }; |
| 463 | #else /* CONFIG_USERFAULTFD */ |
| 464 | #define NULL_VM_UFFD_CTX ((struct vm_userfaultfd_ctx) {}) |
| 465 | struct vm_userfaultfd_ctx {}; |
| 466 | #endif /* CONFIG_USERFAULTFD */ |
| 467 | |
| 468 | struct anon_vma_name { |
| 469 | struct kref kref; |
| 470 | /* The name needs to be at the end because it is dynamically sized. */ |
| 471 | char name[]; |
| 472 | }; |
| 473 | |
| 474 | struct vma_lock { |
| 475 | struct rw_semaphore lock; |
| 476 | }; |
| 477 | |
| 478 | struct vma_numab_state { |
| 479 | unsigned long next_scan; |
| 480 | unsigned long next_pid_reset; |
| 481 | unsigned long access_pids[2]; |
| 482 | }; |
| 483 | |
| 484 | /* |
| 485 | * This struct describes a virtual memory area. There is one of these |
| 486 | * per VM-area/task. A VM area is any part of the process virtual memory |
| 487 | * space that has a special rule for the page-fault handlers (ie a shared |
| 488 | * library, the executable area etc). |
| 489 | */ |
| 490 | struct vm_area_struct { |
| 491 | /* The first cache line has the info for VMA tree walking. */ |
| 492 | |
| 493 | union { |
| 494 | struct { |
| 495 | /* VMA covers [vm_start; vm_end) addresses within mm */ |
| 496 | unsigned long vm_start; |
| 497 | unsigned long vm_end; |
| 498 | }; |
| 499 | #ifdef CONFIG_PER_VMA_LOCK |
| 500 | struct rcu_head vm_rcu; /* Used for deferred freeing. */ |
| 501 | #endif |
| 502 | }; |
| 503 | |
| 504 | struct mm_struct *vm_mm; /* The address space we belong to. */ |
| 505 | pgprot_t vm_page_prot; /* Access permissions of this VMA. */ |
| 506 | |
| 507 | /* |
| 508 | * Flags, see mm.h. |
| 509 | * To modify use vm_flags_{init|reset|set|clear|mod} functions. |
| 510 | */ |
| 511 | union { |
| 512 | const vm_flags_t vm_flags; |
| 513 | vm_flags_t __private __vm_flags; |
| 514 | }; |
| 515 | |
| 516 | #ifdef CONFIG_PER_VMA_LOCK |
| 517 | int vm_lock_seq; |
| 518 | struct vma_lock *vm_lock; |
| 519 | |
| 520 | /* Flag to indicate areas detached from the mm->mm_mt tree */ |
| 521 | bool detached; |
| 522 | #endif |
| 523 | |
| 524 | /* |
| 525 | * For areas with an address space and backing store, |
| 526 | * linkage into the address_space->i_mmap interval tree. |
| 527 | * |
| 528 | */ |
| 529 | struct { |
| 530 | struct rb_node rb; |
| 531 | unsigned long rb_subtree_last; |
| 532 | } shared; |
| 533 | |
| 534 | /* |
| 535 | * A file's MAP_PRIVATE vma can be in both i_mmap tree and anon_vma |
| 536 | * list, after a COW of one of the file pages. A MAP_SHARED vma |
| 537 | * can only be in the i_mmap tree. An anonymous MAP_PRIVATE, stack |
| 538 | * or brk vma (with NULL file) can only be in an anon_vma list. |
| 539 | */ |
| 540 | struct list_head anon_vma_chain; /* Serialized by mmap_lock & |
| 541 | * page_table_lock */ |
| 542 | struct anon_vma *anon_vma; /* Serialized by page_table_lock */ |
| 543 | |
| 544 | /* Function pointers to deal with this struct. */ |
| 545 | const struct vm_operations_struct *vm_ops; |
| 546 | |
| 547 | /* Information about our backing store: */ |
| 548 | unsigned long vm_pgoff; /* Offset (within vm_file) in PAGE_SIZE |
| 549 | units */ |
| 550 | struct file * vm_file; /* File we map to (can be NULL). */ |
| 551 | void * vm_private_data; /* was vm_pte (shared mem) */ |
| 552 | |
| 553 | #ifdef CONFIG_ANON_VMA_NAME |
| 554 | /* |
| 555 | * For private and shared anonymous mappings, a pointer to a null |
| 556 | * terminated string containing the name given to the vma, or NULL if |
| 557 | * unnamed. Serialized by mmap_lock. Use anon_vma_name to access. |
| 558 | */ |
| 559 | struct anon_vma_name *anon_name; |
| 560 | #endif |
| 561 | #ifdef CONFIG_SWAP |
| 562 | atomic_long_t swap_readahead_info; |
| 563 | #endif |
| 564 | #ifndef CONFIG_MMU |
| 565 | struct vm_region *vm_region; /* NOMMU mapping region */ |
| 566 | #endif |
| 567 | #ifdef CONFIG_NUMA |
| 568 | struct mempolicy *vm_policy; /* NUMA policy for the VMA */ |
| 569 | #endif |
| 570 | #ifdef CONFIG_NUMA_BALANCING |
| 571 | struct vma_numab_state *numab_state; /* NUMA Balancing state */ |
| 572 | #endif |
| 573 | struct vm_userfaultfd_ctx vm_userfaultfd_ctx; |
| 574 | } __randomize_layout; |
| 575 | |
| 576 | #ifdef CONFIG_SCHED_MM_CID |
| 577 | struct mm_cid { |
| 578 | u64 time; |
| 579 | int cid; |
| 580 | }; |
| 581 | #endif |
| 582 | |
| 583 | struct kioctx_table; |
| 584 | struct mm_struct { |
| 585 | struct { |
| 586 | struct maple_tree mm_mt; |
| 587 | #ifdef CONFIG_MMU |
| 588 | unsigned long (*get_unmapped_area) (struct file *filp, |
| 589 | unsigned long addr, unsigned long len, |
| 590 | unsigned long pgoff, unsigned long flags); |
| 591 | #endif |
| 592 | unsigned long mmap_base; /* base of mmap area */ |
| 593 | unsigned long mmap_legacy_base; /* base of mmap area in bottom-up allocations */ |
| 594 | #ifdef CONFIG_HAVE_ARCH_COMPAT_MMAP_BASES |
| 595 | /* Base addresses for compatible mmap() */ |
| 596 | unsigned long mmap_compat_base; |
| 597 | unsigned long mmap_compat_legacy_base; |
| 598 | #endif |
| 599 | unsigned long task_size; /* size of task vm space */ |
| 600 | pgd_t * pgd; |
| 601 | |
| 602 | #ifdef CONFIG_MEMBARRIER |
| 603 | /** |
| 604 | * @membarrier_state: Flags controlling membarrier behavior. |
| 605 | * |
| 606 | * This field is close to @pgd to hopefully fit in the same |
| 607 | * cache-line, which needs to be touched by switch_mm(). |
| 608 | */ |
| 609 | atomic_t membarrier_state; |
| 610 | #endif |
| 611 | |
| 612 | /** |
| 613 | * @mm_users: The number of users including userspace. |
| 614 | * |
| 615 | * Use mmget()/mmget_not_zero()/mmput() to modify. When this |
| 616 | * drops to 0 (i.e. when the task exits and there are no other |
| 617 | * temporary reference holders), we also release a reference on |
| 618 | * @mm_count (which may then free the &struct mm_struct if |
| 619 | * @mm_count also drops to 0). |
| 620 | */ |
| 621 | atomic_t mm_users; |
| 622 | |
| 623 | /** |
| 624 | * @mm_count: The number of references to &struct mm_struct |
| 625 | * (@mm_users count as 1). |
| 626 | * |
| 627 | * Use mmgrab()/mmdrop() to modify. When this drops to 0, the |
| 628 | * &struct mm_struct is freed. |
| 629 | */ |
| 630 | atomic_t mm_count; |
| 631 | #ifdef CONFIG_SCHED_MM_CID |
| 632 | /** |
| 633 | * @pcpu_cid: Per-cpu current cid. |
| 634 | * |
| 635 | * Keep track of the currently allocated mm_cid for each cpu. |
| 636 | * The per-cpu mm_cid values are serialized by their respective |
| 637 | * runqueue locks. |
| 638 | */ |
| 639 | struct mm_cid __percpu *pcpu_cid; |
| 640 | /* |
| 641 | * @mm_cid_next_scan: Next mm_cid scan (in jiffies). |
| 642 | * |
| 643 | * When the next mm_cid scan is due (in jiffies). |
| 644 | */ |
| 645 | unsigned long mm_cid_next_scan; |
| 646 | #endif |
| 647 | #ifdef CONFIG_MMU |
| 648 | atomic_long_t pgtables_bytes; /* size of all page tables */ |
| 649 | #endif |
| 650 | int map_count; /* number of VMAs */ |
| 651 | |
| 652 | spinlock_t page_table_lock; /* Protects page tables and some |
| 653 | * counters |
| 654 | */ |
| 655 | /* |
| 656 | * With some kernel config, the current mmap_lock's offset |
| 657 | * inside 'mm_struct' is at 0x120, which is very optimal, as |
| 658 | * its two hot fields 'count' and 'owner' sit in 2 different |
| 659 | * cachelines, and when mmap_lock is highly contended, both |
| 660 | * of the 2 fields will be accessed frequently, current layout |
| 661 | * will help to reduce cache bouncing. |
| 662 | * |
| 663 | * So please be careful with adding new fields before |
| 664 | * mmap_lock, which can easily push the 2 fields into one |
| 665 | * cacheline. |
| 666 | */ |
| 667 | struct rw_semaphore mmap_lock; |
| 668 | |
| 669 | struct list_head mmlist; /* List of maybe swapped mm's. These |
| 670 | * are globally strung together off |
| 671 | * init_mm.mmlist, and are protected |
| 672 | * by mmlist_lock |
| 673 | */ |
| 674 | #ifdef CONFIG_PER_VMA_LOCK |
| 675 | int mm_lock_seq; |
| 676 | #endif |
| 677 | |
| 678 | |
| 679 | unsigned long hiwater_rss; /* High-watermark of RSS usage */ |
| 680 | unsigned long hiwater_vm; /* High-water virtual memory usage */ |
| 681 | |
| 682 | unsigned long total_vm; /* Total pages mapped */ |
| 683 | unsigned long locked_vm; /* Pages that have PG_mlocked set */ |
| 684 | atomic64_t pinned_vm; /* Refcount permanently increased */ |
| 685 | unsigned long data_vm; /* VM_WRITE & ~VM_SHARED & ~VM_STACK */ |
| 686 | unsigned long exec_vm; /* VM_EXEC & ~VM_WRITE & ~VM_STACK */ |
| 687 | unsigned long stack_vm; /* VM_STACK */ |
| 688 | unsigned long def_flags; |
| 689 | |
| 690 | /** |
| 691 | * @write_protect_seq: Locked when any thread is write |
| 692 | * protecting pages mapped by this mm to enforce a later COW, |
| 693 | * for instance during page table copying for fork(). |
| 694 | */ |
| 695 | seqcount_t write_protect_seq; |
| 696 | |
| 697 | spinlock_t arg_lock; /* protect the below fields */ |
| 698 | |
| 699 | unsigned long start_code, end_code, start_data, end_data; |
| 700 | unsigned long start_brk, brk, start_stack; |
| 701 | unsigned long arg_start, arg_end, env_start, env_end; |
| 702 | |
| 703 | unsigned long saved_auxv[AT_VECTOR_SIZE]; /* for /proc/PID/auxv */ |
| 704 | |
| 705 | struct percpu_counter rss_stat[NR_MM_COUNTERS]; |
| 706 | |
| 707 | struct linux_binfmt *binfmt; |
| 708 | |
| 709 | /* Architecture-specific MM context */ |
| 710 | mm_context_t context; |
| 711 | |
| 712 | unsigned long flags; /* Must use atomic bitops to access */ |
| 713 | |
| 714 | #ifdef CONFIG_AIO |
| 715 | spinlock_t ioctx_lock; |
| 716 | struct kioctx_table __rcu *ioctx_table; |
| 717 | #endif |
| 718 | #ifdef CONFIG_MEMCG |
| 719 | /* |
| 720 | * "owner" points to a task that is regarded as the canonical |
| 721 | * user/owner of this mm. All of the following must be true in |
| 722 | * order for it to be changed: |
| 723 | * |
| 724 | * current == mm->owner |
| 725 | * current->mm != mm |
| 726 | * new_owner->mm == mm |
| 727 | * new_owner->alloc_lock is held |
| 728 | */ |
| 729 | struct task_struct __rcu *owner; |
| 730 | #endif |
| 731 | struct user_namespace *user_ns; |
| 732 | |
| 733 | /* store ref to file /proc/<pid>/exe symlink points to */ |
| 734 | struct file __rcu *exe_file; |
| 735 | #ifdef CONFIG_MMU_NOTIFIER |
| 736 | struct mmu_notifier_subscriptions *notifier_subscriptions; |
| 737 | #endif |
| 738 | #if defined(CONFIG_TRANSPARENT_HUGEPAGE) && !USE_SPLIT_PMD_PTLOCKS |
| 739 | pgtable_t pmd_huge_pte; /* protected by page_table_lock */ |
| 740 | #endif |
| 741 | #ifdef CONFIG_NUMA_BALANCING |
| 742 | /* |
| 743 | * numa_next_scan is the next time that PTEs will be remapped |
| 744 | * PROT_NONE to trigger NUMA hinting faults; such faults gather |
| 745 | * statistics and migrate pages to new nodes if necessary. |
| 746 | */ |
| 747 | unsigned long numa_next_scan; |
| 748 | |
| 749 | /* Restart point for scanning and remapping PTEs. */ |
| 750 | unsigned long numa_scan_offset; |
| 751 | |
| 752 | /* numa_scan_seq prevents two threads remapping PTEs. */ |
| 753 | int numa_scan_seq; |
| 754 | #endif |
| 755 | /* |
| 756 | * An operation with batched TLB flushing is going on. Anything |
| 757 | * that can move process memory needs to flush the TLB when |
| 758 | * moving a PROT_NONE mapped page. |
| 759 | */ |
| 760 | atomic_t tlb_flush_pending; |
| 761 | #ifdef CONFIG_ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH |
| 762 | /* See flush_tlb_batched_pending() */ |
| 763 | atomic_t tlb_flush_batched; |
| 764 | #endif |
| 765 | struct uprobes_state uprobes_state; |
| 766 | #ifdef CONFIG_PREEMPT_RT |
| 767 | struct rcu_head delayed_drop; |
| 768 | #endif |
| 769 | #ifdef CONFIG_HUGETLB_PAGE |
| 770 | atomic_long_t hugetlb_usage; |
| 771 | #endif |
| 772 | struct work_struct async_put_work; |
| 773 | |
| 774 | #ifdef CONFIG_IOMMU_SVA |
| 775 | u32 pasid; |
| 776 | #endif |
| 777 | #ifdef CONFIG_KSM |
| 778 | /* |
| 779 | * Represent how many pages of this process are involved in KSM |
| 780 | * merging. |
| 781 | */ |
| 782 | unsigned long ksm_merging_pages; |
| 783 | /* |
| 784 | * Represent how many pages are checked for ksm merging |
| 785 | * including merged and not merged. |
| 786 | */ |
| 787 | unsigned long ksm_rmap_items; |
| 788 | #endif |
| 789 | #ifdef CONFIG_LRU_GEN |
| 790 | struct { |
| 791 | /* this mm_struct is on lru_gen_mm_list */ |
| 792 | struct list_head list; |
| 793 | /* |
| 794 | * Set when switching to this mm_struct, as a hint of |
| 795 | * whether it has been used since the last time per-node |
| 796 | * page table walkers cleared the corresponding bits. |
| 797 | */ |
| 798 | unsigned long bitmap; |
| 799 | #ifdef CONFIG_MEMCG |
| 800 | /* points to the memcg of "owner" above */ |
| 801 | struct mem_cgroup *memcg; |
| 802 | #endif |
| 803 | } lru_gen; |
| 804 | #endif /* CONFIG_LRU_GEN */ |
| 805 | } __randomize_layout; |
| 806 | |
| 807 | /* |
| 808 | * The mm_cpumask needs to be at the end of mm_struct, because it |
| 809 | * is dynamically sized based on nr_cpu_ids. |
| 810 | */ |
| 811 | unsigned long cpu_bitmap[]; |
| 812 | }; |
| 813 | |
| 814 | #define MM_MT_FLAGS (MT_FLAGS_ALLOC_RANGE | MT_FLAGS_LOCK_EXTERN | \ |
| 815 | MT_FLAGS_USE_RCU) |
| 816 | extern struct mm_struct init_mm; |
| 817 | |
| 818 | /* Pointer magic because the dynamic array size confuses some compilers. */ |
| 819 | static inline void mm_init_cpumask(struct mm_struct *mm) |
| 820 | { |
| 821 | unsigned long cpu_bitmap = (unsigned long)mm; |
| 822 | |
| 823 | cpu_bitmap += offsetof(struct mm_struct, cpu_bitmap); |
| 824 | cpumask_clear((struct cpumask *)cpu_bitmap); |
| 825 | } |
| 826 | |
| 827 | /* Future-safe accessor for struct mm_struct's cpu_vm_mask. */ |
| 828 | static inline cpumask_t *mm_cpumask(struct mm_struct *mm) |
| 829 | { |
| 830 | return (struct cpumask *)&mm->cpu_bitmap; |
| 831 | } |
| 832 | |
| 833 | #ifdef CONFIG_LRU_GEN |
| 834 | |
| 835 | struct lru_gen_mm_list { |
| 836 | /* mm_struct list for page table walkers */ |
| 837 | struct list_head fifo; |
| 838 | /* protects the list above */ |
| 839 | spinlock_t lock; |
| 840 | }; |
| 841 | |
| 842 | void lru_gen_add_mm(struct mm_struct *mm); |
| 843 | void lru_gen_del_mm(struct mm_struct *mm); |
| 844 | #ifdef CONFIG_MEMCG |
| 845 | void lru_gen_migrate_mm(struct mm_struct *mm); |
| 846 | #endif |
| 847 | |
| 848 | static inline void lru_gen_init_mm(struct mm_struct *mm) |
| 849 | { |
| 850 | INIT_LIST_HEAD(&mm->lru_gen.list); |
| 851 | mm->lru_gen.bitmap = 0; |
| 852 | #ifdef CONFIG_MEMCG |
| 853 | mm->lru_gen.memcg = NULL; |
| 854 | #endif |
| 855 | } |
| 856 | |
| 857 | static inline void lru_gen_use_mm(struct mm_struct *mm) |
| 858 | { |
| 859 | /* |
| 860 | * When the bitmap is set, page reclaim knows this mm_struct has been |
| 861 | * used since the last time it cleared the bitmap. So it might be worth |
| 862 | * walking the page tables of this mm_struct to clear the accessed bit. |
| 863 | */ |
| 864 | WRITE_ONCE(mm->lru_gen.bitmap, -1); |
| 865 | } |
| 866 | |
| 867 | #else /* !CONFIG_LRU_GEN */ |
| 868 | |
| 869 | static inline void lru_gen_add_mm(struct mm_struct *mm) |
| 870 | { |
| 871 | } |
| 872 | |
| 873 | static inline void lru_gen_del_mm(struct mm_struct *mm) |
| 874 | { |
| 875 | } |
| 876 | |
| 877 | #ifdef CONFIG_MEMCG |
| 878 | static inline void lru_gen_migrate_mm(struct mm_struct *mm) |
| 879 | { |
| 880 | } |
| 881 | #endif |
| 882 | |
| 883 | static inline void lru_gen_init_mm(struct mm_struct *mm) |
| 884 | { |
| 885 | } |
| 886 | |
| 887 | static inline void lru_gen_use_mm(struct mm_struct *mm) |
| 888 | { |
| 889 | } |
| 890 | |
| 891 | #endif /* CONFIG_LRU_GEN */ |
| 892 | |
| 893 | struct vma_iterator { |
| 894 | struct ma_state mas; |
| 895 | }; |
| 896 | |
| 897 | #define VMA_ITERATOR(name, __mm, __addr) \ |
| 898 | struct vma_iterator name = { \ |
| 899 | .mas = { \ |
| 900 | .tree = &(__mm)->mm_mt, \ |
| 901 | .index = __addr, \ |
| 902 | .node = MAS_START, \ |
| 903 | }, \ |
| 904 | } |
| 905 | |
| 906 | static inline void vma_iter_init(struct vma_iterator *vmi, |
| 907 | struct mm_struct *mm, unsigned long addr) |
| 908 | { |
| 909 | mas_init(&vmi->mas, &mm->mm_mt, addr); |
| 910 | } |
| 911 | |
| 912 | #ifdef CONFIG_SCHED_MM_CID |
| 913 | |
| 914 | enum mm_cid_state { |
| 915 | MM_CID_UNSET = -1U, /* Unset state has lazy_put flag set. */ |
| 916 | MM_CID_LAZY_PUT = (1U << 31), |
| 917 | }; |
| 918 | |
| 919 | static inline bool mm_cid_is_unset(int cid) |
| 920 | { |
| 921 | return cid == MM_CID_UNSET; |
| 922 | } |
| 923 | |
| 924 | static inline bool mm_cid_is_lazy_put(int cid) |
| 925 | { |
| 926 | return !mm_cid_is_unset(cid) && (cid & MM_CID_LAZY_PUT); |
| 927 | } |
| 928 | |
| 929 | static inline bool mm_cid_is_valid(int cid) |
| 930 | { |
| 931 | return !(cid & MM_CID_LAZY_PUT); |
| 932 | } |
| 933 | |
| 934 | static inline int mm_cid_set_lazy_put(int cid) |
| 935 | { |
| 936 | return cid | MM_CID_LAZY_PUT; |
| 937 | } |
| 938 | |
| 939 | static inline int mm_cid_clear_lazy_put(int cid) |
| 940 | { |
| 941 | return cid & ~MM_CID_LAZY_PUT; |
| 942 | } |
| 943 | |
| 944 | /* Accessor for struct mm_struct's cidmask. */ |
| 945 | static inline cpumask_t *mm_cidmask(struct mm_struct *mm) |
| 946 | { |
| 947 | unsigned long cid_bitmap = (unsigned long)mm; |
| 948 | |
| 949 | cid_bitmap += offsetof(struct mm_struct, cpu_bitmap); |
| 950 | /* Skip cpu_bitmap */ |
| 951 | cid_bitmap += cpumask_size(); |
| 952 | return (struct cpumask *)cid_bitmap; |
| 953 | } |
| 954 | |
| 955 | static inline void mm_init_cid(struct mm_struct *mm) |
| 956 | { |
| 957 | int i; |
| 958 | |
| 959 | for_each_possible_cpu(i) { |
| 960 | struct mm_cid *pcpu_cid = per_cpu_ptr(mm->pcpu_cid, i); |
| 961 | |
| 962 | pcpu_cid->cid = MM_CID_UNSET; |
| 963 | pcpu_cid->time = 0; |
| 964 | } |
| 965 | cpumask_clear(mm_cidmask(mm)); |
| 966 | } |
| 967 | |
| 968 | static inline int mm_alloc_cid(struct mm_struct *mm) |
| 969 | { |
| 970 | mm->pcpu_cid = alloc_percpu(struct mm_cid); |
| 971 | if (!mm->pcpu_cid) |
| 972 | return -ENOMEM; |
| 973 | mm_init_cid(mm); |
| 974 | return 0; |
| 975 | } |
| 976 | |
| 977 | static inline void mm_destroy_cid(struct mm_struct *mm) |
| 978 | { |
| 979 | free_percpu(mm->pcpu_cid); |
| 980 | mm->pcpu_cid = NULL; |
| 981 | } |
| 982 | |
| 983 | static inline unsigned int mm_cid_size(void) |
| 984 | { |
| 985 | return cpumask_size(); |
| 986 | } |
| 987 | #else /* CONFIG_SCHED_MM_CID */ |
| 988 | static inline void mm_init_cid(struct mm_struct *mm) { } |
| 989 | static inline int mm_alloc_cid(struct mm_struct *mm) { return 0; } |
| 990 | static inline void mm_destroy_cid(struct mm_struct *mm) { } |
| 991 | static inline unsigned int mm_cid_size(void) |
| 992 | { |
| 993 | return 0; |
| 994 | } |
| 995 | #endif /* CONFIG_SCHED_MM_CID */ |
| 996 | |
| 997 | struct mmu_gather; |
| 998 | extern void tlb_gather_mmu(struct mmu_gather *tlb, struct mm_struct *mm); |
| 999 | extern void tlb_gather_mmu_fullmm(struct mmu_gather *tlb, struct mm_struct *mm); |
| 1000 | extern void tlb_finish_mmu(struct mmu_gather *tlb); |
| 1001 | |
| 1002 | struct vm_fault; |
| 1003 | |
| 1004 | /** |
| 1005 | * typedef vm_fault_t - Return type for page fault handlers. |
| 1006 | * |
| 1007 | * Page fault handlers return a bitmask of %VM_FAULT values. |
| 1008 | */ |
| 1009 | typedef __bitwise unsigned int vm_fault_t; |
| 1010 | |
| 1011 | /** |
| 1012 | * enum vm_fault_reason - Page fault handlers return a bitmask of |
| 1013 | * these values to tell the core VM what happened when handling the |
| 1014 | * fault. Used to decide whether a process gets delivered SIGBUS or |
| 1015 | * just gets major/minor fault counters bumped up. |
| 1016 | * |
| 1017 | * @VM_FAULT_OOM: Out Of Memory |
| 1018 | * @VM_FAULT_SIGBUS: Bad access |
| 1019 | * @VM_FAULT_MAJOR: Page read from storage |
| 1020 | * @VM_FAULT_HWPOISON: Hit poisoned small page |
| 1021 | * @VM_FAULT_HWPOISON_LARGE: Hit poisoned large page. Index encoded |
| 1022 | * in upper bits |
| 1023 | * @VM_FAULT_SIGSEGV: segmentation fault |
| 1024 | * @VM_FAULT_NOPAGE: ->fault installed the pte, not return page |
| 1025 | * @VM_FAULT_LOCKED: ->fault locked the returned page |
| 1026 | * @VM_FAULT_RETRY: ->fault blocked, must retry |
| 1027 | * @VM_FAULT_FALLBACK: huge page fault failed, fall back to small |
| 1028 | * @VM_FAULT_DONE_COW: ->fault has fully handled COW |
| 1029 | * @VM_FAULT_NEEDDSYNC: ->fault did not modify page tables and needs |
| 1030 | * fsync() to complete (for synchronous page faults |
| 1031 | * in DAX) |
| 1032 | * @VM_FAULT_COMPLETED: ->fault completed, meanwhile mmap lock released |
| 1033 | * @VM_FAULT_HINDEX_MASK: mask HINDEX value |
| 1034 | * |
| 1035 | */ |
| 1036 | enum vm_fault_reason { |
| 1037 | VM_FAULT_OOM = (__force vm_fault_t)0x000001, |
| 1038 | VM_FAULT_SIGBUS = (__force vm_fault_t)0x000002, |
| 1039 | VM_FAULT_MAJOR = (__force vm_fault_t)0x000004, |
| 1040 | VM_FAULT_HWPOISON = (__force vm_fault_t)0x000010, |
| 1041 | VM_FAULT_HWPOISON_LARGE = (__force vm_fault_t)0x000020, |
| 1042 | VM_FAULT_SIGSEGV = (__force vm_fault_t)0x000040, |
| 1043 | VM_FAULT_NOPAGE = (__force vm_fault_t)0x000100, |
| 1044 | VM_FAULT_LOCKED = (__force vm_fault_t)0x000200, |
| 1045 | VM_FAULT_RETRY = (__force vm_fault_t)0x000400, |
| 1046 | VM_FAULT_FALLBACK = (__force vm_fault_t)0x000800, |
| 1047 | VM_FAULT_DONE_COW = (__force vm_fault_t)0x001000, |
| 1048 | VM_FAULT_NEEDDSYNC = (__force vm_fault_t)0x002000, |
| 1049 | VM_FAULT_COMPLETED = (__force vm_fault_t)0x004000, |
| 1050 | VM_FAULT_HINDEX_MASK = (__force vm_fault_t)0x0f0000, |
| 1051 | }; |
| 1052 | |
| 1053 | /* Encode hstate index for a hwpoisoned large page */ |
| 1054 | #define VM_FAULT_SET_HINDEX(x) ((__force vm_fault_t)((x) << 16)) |
| 1055 | #define VM_FAULT_GET_HINDEX(x) (((__force unsigned int)(x) >> 16) & 0xf) |
| 1056 | |
| 1057 | #define VM_FAULT_ERROR (VM_FAULT_OOM | VM_FAULT_SIGBUS | \ |
| 1058 | VM_FAULT_SIGSEGV | VM_FAULT_HWPOISON | \ |
| 1059 | VM_FAULT_HWPOISON_LARGE | VM_FAULT_FALLBACK) |
| 1060 | |
| 1061 | #define VM_FAULT_RESULT_TRACE \ |
| 1062 | { VM_FAULT_OOM, "OOM" }, \ |
| 1063 | { VM_FAULT_SIGBUS, "SIGBUS" }, \ |
| 1064 | { VM_FAULT_MAJOR, "MAJOR" }, \ |
| 1065 | { VM_FAULT_HWPOISON, "HWPOISON" }, \ |
| 1066 | { VM_FAULT_HWPOISON_LARGE, "HWPOISON_LARGE" }, \ |
| 1067 | { VM_FAULT_SIGSEGV, "SIGSEGV" }, \ |
| 1068 | { VM_FAULT_NOPAGE, "NOPAGE" }, \ |
| 1069 | { VM_FAULT_LOCKED, "LOCKED" }, \ |
| 1070 | { VM_FAULT_RETRY, "RETRY" }, \ |
| 1071 | { VM_FAULT_FALLBACK, "FALLBACK" }, \ |
| 1072 | { VM_FAULT_DONE_COW, "DONE_COW" }, \ |
| 1073 | { VM_FAULT_NEEDDSYNC, "NEEDDSYNC" } |
| 1074 | |
| 1075 | struct vm_special_mapping { |
| 1076 | const char *name; /* The name, e.g. "[vdso]". */ |
| 1077 | |
| 1078 | /* |
| 1079 | * If .fault is not provided, this points to a |
| 1080 | * NULL-terminated array of pages that back the special mapping. |
| 1081 | * |
| 1082 | * This must not be NULL unless .fault is provided. |
| 1083 | */ |
| 1084 | struct page **pages; |
| 1085 | |
| 1086 | /* |
| 1087 | * If non-NULL, then this is called to resolve page faults |
| 1088 | * on the special mapping. If used, .pages is not checked. |
| 1089 | */ |
| 1090 | vm_fault_t (*fault)(const struct vm_special_mapping *sm, |
| 1091 | struct vm_area_struct *vma, |
| 1092 | struct vm_fault *vmf); |
| 1093 | |
| 1094 | int (*mremap)(const struct vm_special_mapping *sm, |
| 1095 | struct vm_area_struct *new_vma); |
| 1096 | }; |
| 1097 | |
| 1098 | enum tlb_flush_reason { |
| 1099 | TLB_FLUSH_ON_TASK_SWITCH, |
| 1100 | TLB_REMOTE_SHOOTDOWN, |
| 1101 | TLB_LOCAL_SHOOTDOWN, |
| 1102 | TLB_LOCAL_MM_SHOOTDOWN, |
| 1103 | TLB_REMOTE_SEND_IPI, |
| 1104 | NR_TLB_FLUSH_REASONS, |
| 1105 | }; |
| 1106 | |
| 1107 | /* |
| 1108 | * A swap entry has to fit into a "unsigned long", as the entry is hidden |
| 1109 | * in the "index" field of the swapper address space. |
| 1110 | */ |
| 1111 | typedef struct { |
| 1112 | unsigned long val; |
| 1113 | } swp_entry_t; |
| 1114 | |
| 1115 | /** |
| 1116 | * enum fault_flag - Fault flag definitions. |
| 1117 | * @FAULT_FLAG_WRITE: Fault was a write fault. |
| 1118 | * @FAULT_FLAG_MKWRITE: Fault was mkwrite of existing PTE. |
| 1119 | * @FAULT_FLAG_ALLOW_RETRY: Allow to retry the fault if blocked. |
| 1120 | * @FAULT_FLAG_RETRY_NOWAIT: Don't drop mmap_lock and wait when retrying. |
| 1121 | * @FAULT_FLAG_KILLABLE: The fault task is in SIGKILL killable region. |
| 1122 | * @FAULT_FLAG_TRIED: The fault has been tried once. |
| 1123 | * @FAULT_FLAG_USER: The fault originated in userspace. |
| 1124 | * @FAULT_FLAG_REMOTE: The fault is not for current task/mm. |
| 1125 | * @FAULT_FLAG_INSTRUCTION: The fault was during an instruction fetch. |
| 1126 | * @FAULT_FLAG_INTERRUPTIBLE: The fault can be interrupted by non-fatal signals. |
| 1127 | * @FAULT_FLAG_UNSHARE: The fault is an unsharing request to break COW in a |
| 1128 | * COW mapping, making sure that an exclusive anon page is |
| 1129 | * mapped after the fault. |
| 1130 | * @FAULT_FLAG_ORIG_PTE_VALID: whether the fault has vmf->orig_pte cached. |
| 1131 | * We should only access orig_pte if this flag set. |
| 1132 | * @FAULT_FLAG_VMA_LOCK: The fault is handled under VMA lock. |
| 1133 | * |
| 1134 | * About @FAULT_FLAG_ALLOW_RETRY and @FAULT_FLAG_TRIED: we can specify |
| 1135 | * whether we would allow page faults to retry by specifying these two |
| 1136 | * fault flags correctly. Currently there can be three legal combinations: |
| 1137 | * |
| 1138 | * (a) ALLOW_RETRY and !TRIED: this means the page fault allows retry, and |
| 1139 | * this is the first try |
| 1140 | * |
| 1141 | * (b) ALLOW_RETRY and TRIED: this means the page fault allows retry, and |
| 1142 | * we've already tried at least once |
| 1143 | * |
| 1144 | * (c) !ALLOW_RETRY and !TRIED: this means the page fault does not allow retry |
| 1145 | * |
| 1146 | * The unlisted combination (!ALLOW_RETRY && TRIED) is illegal and should never |
| 1147 | * be used. Note that page faults can be allowed to retry for multiple times, |
| 1148 | * in which case we'll have an initial fault with flags (a) then later on |
| 1149 | * continuous faults with flags (b). We should always try to detect pending |
| 1150 | * signals before a retry to make sure the continuous page faults can still be |
| 1151 | * interrupted if necessary. |
| 1152 | * |
| 1153 | * The combination FAULT_FLAG_WRITE|FAULT_FLAG_UNSHARE is illegal. |
| 1154 | * FAULT_FLAG_UNSHARE is ignored and treated like an ordinary read fault when |
| 1155 | * applied to mappings that are not COW mappings. |
| 1156 | */ |
| 1157 | enum fault_flag { |
| 1158 | FAULT_FLAG_WRITE = 1 << 0, |
| 1159 | FAULT_FLAG_MKWRITE = 1 << 1, |
| 1160 | FAULT_FLAG_ALLOW_RETRY = 1 << 2, |
| 1161 | FAULT_FLAG_RETRY_NOWAIT = 1 << 3, |
| 1162 | FAULT_FLAG_KILLABLE = 1 << 4, |
| 1163 | FAULT_FLAG_TRIED = 1 << 5, |
| 1164 | FAULT_FLAG_USER = 1 << 6, |
| 1165 | FAULT_FLAG_REMOTE = 1 << 7, |
| 1166 | FAULT_FLAG_INSTRUCTION = 1 << 8, |
| 1167 | FAULT_FLAG_INTERRUPTIBLE = 1 << 9, |
| 1168 | FAULT_FLAG_UNSHARE = 1 << 10, |
| 1169 | FAULT_FLAG_ORIG_PTE_VALID = 1 << 11, |
| 1170 | FAULT_FLAG_VMA_LOCK = 1 << 12, |
| 1171 | }; |
| 1172 | |
| 1173 | typedef unsigned int __bitwise zap_flags_t; |
| 1174 | |
| 1175 | /* |
| 1176 | * FOLL_PIN and FOLL_LONGTERM may be used in various combinations with each |
| 1177 | * other. Here is what they mean, and how to use them: |
| 1178 | * |
| 1179 | * |
| 1180 | * FIXME: For pages which are part of a filesystem, mappings are subject to the |
| 1181 | * lifetime enforced by the filesystem and we need guarantees that longterm |
| 1182 | * users like RDMA and V4L2 only establish mappings which coordinate usage with |
| 1183 | * the filesystem. Ideas for this coordination include revoking the longterm |
| 1184 | * pin, delaying writeback, bounce buffer page writeback, etc. As FS DAX was |
| 1185 | * added after the problem with filesystems was found FS DAX VMAs are |
| 1186 | * specifically failed. Filesystem pages are still subject to bugs and use of |
| 1187 | * FOLL_LONGTERM should be avoided on those pages. |
| 1188 | * |
| 1189 | * In the CMA case: long term pins in a CMA region would unnecessarily fragment |
| 1190 | * that region. And so, CMA attempts to migrate the page before pinning, when |
| 1191 | * FOLL_LONGTERM is specified. |
| 1192 | * |
| 1193 | * FOLL_PIN indicates that a special kind of tracking (not just page->_refcount, |
| 1194 | * but an additional pin counting system) will be invoked. This is intended for |
| 1195 | * anything that gets a page reference and then touches page data (for example, |
| 1196 | * Direct IO). This lets the filesystem know that some non-file-system entity is |
| 1197 | * potentially changing the pages' data. In contrast to FOLL_GET (whose pages |
| 1198 | * are released via put_page()), FOLL_PIN pages must be released, ultimately, by |
| 1199 | * a call to unpin_user_page(). |
| 1200 | * |
| 1201 | * FOLL_PIN is similar to FOLL_GET: both of these pin pages. They use different |
| 1202 | * and separate refcounting mechanisms, however, and that means that each has |
| 1203 | * its own acquire and release mechanisms: |
| 1204 | * |
| 1205 | * FOLL_GET: get_user_pages*() to acquire, and put_page() to release. |
| 1206 | * |
| 1207 | * FOLL_PIN: pin_user_pages*() to acquire, and unpin_user_pages to release. |
| 1208 | * |
| 1209 | * FOLL_PIN and FOLL_GET are mutually exclusive for a given function call. |
| 1210 | * (The underlying pages may experience both FOLL_GET-based and FOLL_PIN-based |
| 1211 | * calls applied to them, and that's perfectly OK. This is a constraint on the |
| 1212 | * callers, not on the pages.) |
| 1213 | * |
| 1214 | * FOLL_PIN should be set internally by the pin_user_pages*() APIs, never |
| 1215 | * directly by the caller. That's in order to help avoid mismatches when |
| 1216 | * releasing pages: get_user_pages*() pages must be released via put_page(), |
| 1217 | * while pin_user_pages*() pages must be released via unpin_user_page(). |
| 1218 | * |
| 1219 | * Please see Documentation/core-api/pin_user_pages.rst for more information. |
| 1220 | */ |
| 1221 | |
| 1222 | enum { |
| 1223 | /* check pte is writable */ |
| 1224 | FOLL_WRITE = 1 << 0, |
| 1225 | /* do get_page on page */ |
| 1226 | FOLL_GET = 1 << 1, |
| 1227 | /* give error on hole if it would be zero */ |
| 1228 | FOLL_DUMP = 1 << 2, |
| 1229 | /* get_user_pages read/write w/o permission */ |
| 1230 | FOLL_FORCE = 1 << 3, |
| 1231 | /* |
| 1232 | * if a disk transfer is needed, start the IO and return without waiting |
| 1233 | * upon it |
| 1234 | */ |
| 1235 | FOLL_NOWAIT = 1 << 4, |
| 1236 | /* do not fault in pages */ |
| 1237 | FOLL_NOFAULT = 1 << 5, |
| 1238 | /* check page is hwpoisoned */ |
| 1239 | FOLL_HWPOISON = 1 << 6, |
| 1240 | /* don't do file mappings */ |
| 1241 | FOLL_ANON = 1 << 7, |
| 1242 | /* |
| 1243 | * FOLL_LONGTERM indicates that the page will be held for an indefinite |
| 1244 | * time period _often_ under userspace control. This is in contrast to |
| 1245 | * iov_iter_get_pages(), whose usages are transient. |
| 1246 | */ |
| 1247 | FOLL_LONGTERM = 1 << 8, |
| 1248 | /* split huge pmd before returning */ |
| 1249 | FOLL_SPLIT_PMD = 1 << 9, |
| 1250 | /* allow returning PCI P2PDMA pages */ |
| 1251 | FOLL_PCI_P2PDMA = 1 << 10, |
| 1252 | /* allow interrupts from generic signals */ |
| 1253 | FOLL_INTERRUPTIBLE = 1 << 11, |
| 1254 | |
| 1255 | /* See also internal only FOLL flags in mm/internal.h */ |
| 1256 | }; |
| 1257 | |
| 1258 | #endif /* _LINUX_MM_TYPES_H */ |