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 #include <linux/types.h> 23 24 #include <asm/mmu.h> 25 26 #ifndef AT_VECTOR_SIZE_ARCH 27 #define AT_VECTOR_SIZE_ARCH 0 28 #endif 29 #define AT_VECTOR_SIZE (2*(AT_VECTOR_SIZE_ARCH + AT_VECTOR_SIZE_BASE + 1)) 30 31 32 struct address_space; 33 struct futex_private_hash; 34 struct mem_cgroup; 35 36 /* 37 * Each physical page in the system has a struct page associated with 38 * it to keep track of whatever it is we are using the page for at the 39 * moment. Note that we have no way to track which tasks are using 40 * a page, though if it is a pagecache page, rmap structures can tell us 41 * who is mapping it. 42 * 43 * If you allocate the page using alloc_pages(), you can use some of the 44 * space in struct page for your own purposes. The five words in the main 45 * union are available, except for bit 0 of the first word which must be 46 * kept clear. Many users use this word to store a pointer to an object 47 * which is guaranteed to be aligned. If you use the same storage as 48 * page->mapping, you must restore it to NULL before freeing the page. 49 * 50 * The mapcount field must not be used for own purposes. 51 * 52 * If you want to use the refcount field, it must be used in such a way 53 * that other CPUs temporarily incrementing and then decrementing the 54 * refcount does not cause problems. On receiving the page from 55 * alloc_pages(), the refcount will be positive. 56 * 57 * If you allocate pages of order > 0, you can use some of the fields 58 * in each subpage, but you may need to restore some of their values 59 * afterwards. 60 * 61 * SLUB uses cmpxchg_double() to atomically update its freelist and counters. 62 * That requires that freelist & counters in struct slab be adjacent and 63 * double-word aligned. Because struct slab currently just reinterprets the 64 * bits of struct page, we align all struct pages to double-word boundaries, 65 * and ensure that 'freelist' is aligned within struct slab. 66 */ 67 #ifdef CONFIG_HAVE_ALIGNED_STRUCT_PAGE 68 #define _struct_page_alignment __aligned(2 * sizeof(unsigned long)) 69 #else 70 #define _struct_page_alignment __aligned(sizeof(unsigned long)) 71 #endif 72 73 struct page { 74 unsigned long flags; /* Atomic flags, some possibly 75 * updated asynchronously */ 76 /* 77 * Five words (20/40 bytes) are available in this union. 78 * WARNING: bit 0 of the first word is used for PageTail(). That 79 * means the other users of this union MUST NOT use the bit to 80 * avoid collision and false-positive PageTail(). 81 */ 82 union { 83 struct { /* Page cache and anonymous pages */ 84 /** 85 * @lru: Pageout list, eg. active_list protected by 86 * lruvec->lru_lock. Sometimes used as a generic list 87 * by the page owner. 88 */ 89 union { 90 struct list_head lru; 91 92 /* Or, for the Unevictable "LRU list" slot */ 93 struct { 94 /* Always even, to negate PageTail */ 95 void *__filler; 96 /* Count page's or folio's mlocks */ 97 unsigned int mlock_count; 98 }; 99 100 /* Or, free page */ 101 struct list_head buddy_list; 102 struct list_head pcp_list; 103 struct { 104 struct llist_node pcp_llist; 105 unsigned int order; 106 }; 107 }; 108 struct address_space *mapping; 109 union { 110 pgoff_t __folio_index; /* Our offset within mapping. */ 111 unsigned long share; /* share count for fsdax */ 112 }; 113 /** 114 * @private: Mapping-private opaque data. 115 * Usually used for buffer_heads if PagePrivate. 116 * Used for swp_entry_t if swapcache flag set. 117 * Indicates order in the buddy system if PageBuddy. 118 */ 119 unsigned long private; 120 }; 121 struct { /* page_pool used by netstack */ 122 /** 123 * @pp_magic: magic value to avoid recycling non 124 * page_pool allocated pages. 125 */ 126 unsigned long pp_magic; 127 struct page_pool *pp; 128 unsigned long _pp_mapping_pad; 129 unsigned long dma_addr; 130 atomic_long_t pp_ref_count; 131 }; 132 struct { /* Tail pages of compound page */ 133 unsigned long compound_head; /* Bit zero is set */ 134 }; 135 struct { /* ZONE_DEVICE pages */ 136 /* 137 * The first word is used for compound_head or folio 138 * pgmap 139 */ 140 void *_unused_pgmap_compound_head; 141 void *zone_device_data; 142 /* 143 * ZONE_DEVICE private pages are counted as being 144 * mapped so the next 3 words hold the mapping, index, 145 * and private fields from the source anonymous or 146 * page cache page while the page is migrated to device 147 * private memory. 148 * ZONE_DEVICE MEMORY_DEVICE_FS_DAX pages also 149 * use the mapping, index, and private fields when 150 * pmem backed DAX files are mapped. 151 */ 152 }; 153 154 /** @rcu_head: You can use this to free a page by RCU. */ 155 struct rcu_head rcu_head; 156 }; 157 158 union { /* This union is 4 bytes in size. */ 159 /* 160 * For head pages of typed folios, the value stored here 161 * allows for determining what this page is used for. The 162 * tail pages of typed folios will not store a type 163 * (page_type == _mapcount == -1). 164 * 165 * See page-flags.h for a list of page types which are currently 166 * stored here. 167 * 168 * Owners of typed folios may reuse the lower 16 bit of the 169 * head page page_type field after setting the page type, 170 * but must reset these 16 bit to -1 before clearing the 171 * page type. 172 */ 173 unsigned int page_type; 174 175 /* 176 * For pages that are part of non-typed folios for which mappings 177 * are tracked via the RMAP, encodes the number of times this page 178 * is directly referenced by a page table. 179 * 180 * Note that the mapcount is always initialized to -1, so that 181 * transitions both from it and to it can be tracked, using 182 * atomic_inc_and_test() and atomic_add_negative(-1). 183 */ 184 atomic_t _mapcount; 185 }; 186 187 /* Usage count. *DO NOT USE DIRECTLY*. See page_ref.h */ 188 atomic_t _refcount; 189 190 #ifdef CONFIG_MEMCG 191 unsigned long memcg_data; 192 #elif defined(CONFIG_SLAB_OBJ_EXT) 193 unsigned long _unused_slab_obj_exts; 194 #endif 195 196 /* 197 * On machines where all RAM is mapped into kernel address space, 198 * we can simply calculate the virtual address. On machines with 199 * highmem some memory is mapped into kernel virtual memory 200 * dynamically, so we need a place to store that address. 201 * Note that this field could be 16 bits on x86 ... ;) 202 * 203 * Architectures with slow multiplication can define 204 * WANT_PAGE_VIRTUAL in asm/page.h 205 */ 206 #if defined(WANT_PAGE_VIRTUAL) 207 void *virtual; /* Kernel virtual address (NULL if 208 not kmapped, ie. highmem) */ 209 #endif /* WANT_PAGE_VIRTUAL */ 210 211 #ifdef LAST_CPUPID_NOT_IN_PAGE_FLAGS 212 int _last_cpupid; 213 #endif 214 215 #ifdef CONFIG_KMSAN 216 /* 217 * KMSAN metadata for this page: 218 * - shadow page: every bit indicates whether the corresponding 219 * bit of the original page is initialized (0) or not (1); 220 * - origin page: every 4 bytes contain an id of the stack trace 221 * where the uninitialized value was created. 222 */ 223 struct page *kmsan_shadow; 224 struct page *kmsan_origin; 225 #endif 226 } _struct_page_alignment; 227 228 /* 229 * struct encoded_page - a nonexistent type marking this pointer 230 * 231 * An 'encoded_page' pointer is a pointer to a regular 'struct page', but 232 * with the low bits of the pointer indicating extra context-dependent 233 * information. Only used in mmu_gather handling, and this acts as a type 234 * system check on that use. 235 * 236 * We only really have two guaranteed bits in general, although you could 237 * play with 'struct page' alignment (see CONFIG_HAVE_ALIGNED_STRUCT_PAGE) 238 * for more. 239 * 240 * Use the supplied helper functions to endcode/decode the pointer and bits. 241 */ 242 struct encoded_page; 243 244 #define ENCODED_PAGE_BITS 3ul 245 246 /* Perform rmap removal after we have flushed the TLB. */ 247 #define ENCODED_PAGE_BIT_DELAY_RMAP 1ul 248 249 /* 250 * The next item in an encoded_page array is the "nr_pages" argument, specifying 251 * the number of consecutive pages starting from this page, that all belong to 252 * the same folio. For example, "nr_pages" corresponds to the number of folio 253 * references that must be dropped. If this bit is not set, "nr_pages" is 254 * implicitly 1. 255 */ 256 #define ENCODED_PAGE_BIT_NR_PAGES_NEXT 2ul 257 258 static __always_inline struct encoded_page *encode_page(struct page *page, unsigned long flags) 259 { 260 BUILD_BUG_ON(flags > ENCODED_PAGE_BITS); 261 return (struct encoded_page *)(flags | (unsigned long)page); 262 } 263 264 static inline unsigned long encoded_page_flags(struct encoded_page *page) 265 { 266 return ENCODED_PAGE_BITS & (unsigned long)page; 267 } 268 269 static inline struct page *encoded_page_ptr(struct encoded_page *page) 270 { 271 return (struct page *)(~ENCODED_PAGE_BITS & (unsigned long)page); 272 } 273 274 static __always_inline struct encoded_page *encode_nr_pages(unsigned long nr) 275 { 276 VM_WARN_ON_ONCE((nr << 2) >> 2 != nr); 277 return (struct encoded_page *)(nr << 2); 278 } 279 280 static __always_inline unsigned long encoded_nr_pages(struct encoded_page *page) 281 { 282 return ((unsigned long)page) >> 2; 283 } 284 285 /* 286 * A swap entry has to fit into a "unsigned long", as the entry is hidden 287 * in the "index" field of the swapper address space. 288 */ 289 typedef struct { 290 unsigned long val; 291 } swp_entry_t; 292 293 #if defined(CONFIG_MEMCG) || defined(CONFIG_SLAB_OBJ_EXT) 294 /* We have some extra room after the refcount in tail pages. */ 295 #define NR_PAGES_IN_LARGE_FOLIO 296 #endif 297 298 /* 299 * On 32bit, we can cut the required metadata in half, because: 300 * (a) PID_MAX_LIMIT implicitly limits the number of MMs we could ever have, 301 * so we can limit MM IDs to 15 bit (32767). 302 * (b) We don't expect folios where even a single complete PTE mapping by 303 * one MM would exceed 15 bits (order-15). 304 */ 305 #ifdef CONFIG_64BIT 306 typedef int mm_id_mapcount_t; 307 #define MM_ID_MAPCOUNT_MAX INT_MAX 308 typedef unsigned int mm_id_t; 309 #else /* !CONFIG_64BIT */ 310 typedef short mm_id_mapcount_t; 311 #define MM_ID_MAPCOUNT_MAX SHRT_MAX 312 typedef unsigned short mm_id_t; 313 #endif /* CONFIG_64BIT */ 314 315 /* We implicitly use the dummy ID for init-mm etc. where we never rmap pages. */ 316 #define MM_ID_DUMMY 0 317 #define MM_ID_MIN (MM_ID_DUMMY + 1) 318 319 /* 320 * We leave the highest bit of each MM id unused, so we can store a flag 321 * in the highest bit of each folio->_mm_id[]. 322 */ 323 #define MM_ID_BITS ((sizeof(mm_id_t) * BITS_PER_BYTE) - 1) 324 #define MM_ID_MASK ((1U << MM_ID_BITS) - 1) 325 #define MM_ID_MAX MM_ID_MASK 326 327 /* 328 * In order to use bit_spin_lock(), which requires an unsigned long, we 329 * operate on folio->_mm_ids when working on flags. 330 */ 331 #define FOLIO_MM_IDS_LOCK_BITNUM MM_ID_BITS 332 #define FOLIO_MM_IDS_LOCK_BIT BIT(FOLIO_MM_IDS_LOCK_BITNUM) 333 #define FOLIO_MM_IDS_SHARED_BITNUM (2 * MM_ID_BITS + 1) 334 #define FOLIO_MM_IDS_SHARED_BIT BIT(FOLIO_MM_IDS_SHARED_BITNUM) 335 336 /** 337 * struct folio - Represents a contiguous set of bytes. 338 * @flags: Identical to the page flags. 339 * @lru: Least Recently Used list; tracks how recently this folio was used. 340 * @mlock_count: Number of times this folio has been pinned by mlock(). 341 * @mapping: The file this page belongs to, or refers to the anon_vma for 342 * anonymous memory. 343 * @index: Offset within the file, in units of pages. For anonymous memory, 344 * this is the index from the beginning of the mmap. 345 * @share: number of DAX mappings that reference this folio. See 346 * dax_associate_entry. 347 * @private: Filesystem per-folio data (see folio_attach_private()). 348 * @swap: Used for swp_entry_t if folio_test_swapcache(). 349 * @_mapcount: Do not access this member directly. Use folio_mapcount() to 350 * find out how many times this folio is mapped by userspace. 351 * @_refcount: Do not access this member directly. Use folio_ref_count() 352 * to find how many references there are to this folio. 353 * @memcg_data: Memory Control Group data. 354 * @pgmap: Metadata for ZONE_DEVICE mappings 355 * @virtual: Virtual address in the kernel direct map. 356 * @_last_cpupid: IDs of last CPU and last process that accessed the folio. 357 * @_entire_mapcount: Do not use directly, call folio_entire_mapcount(). 358 * @_large_mapcount: Do not use directly, call folio_mapcount(). 359 * @_nr_pages_mapped: Do not use outside of rmap and debug code. 360 * @_pincount: Do not use directly, call folio_maybe_dma_pinned(). 361 * @_nr_pages: Do not use directly, call folio_nr_pages(). 362 * @_mm_id: Do not use outside of rmap code. 363 * @_mm_ids: Do not use outside of rmap code. 364 * @_mm_id_mapcount: Do not use outside of rmap code. 365 * @_hugetlb_subpool: Do not use directly, use accessor in hugetlb.h. 366 * @_hugetlb_cgroup: Do not use directly, use accessor in hugetlb_cgroup.h. 367 * @_hugetlb_cgroup_rsvd: Do not use directly, use accessor in hugetlb_cgroup.h. 368 * @_hugetlb_hwpoison: Do not use directly, call raw_hwp_list_head(). 369 * @_deferred_list: Folios to be split under memory pressure. 370 * @_unused_slab_obj_exts: Placeholder to match obj_exts in struct slab. 371 * 372 * A folio is a physically, virtually and logically contiguous set 373 * of bytes. It is a power-of-two in size, and it is aligned to that 374 * same power-of-two. It is at least as large as %PAGE_SIZE. If it is 375 * in the page cache, it is at a file offset which is a multiple of that 376 * power-of-two. It may be mapped into userspace at an address which is 377 * at an arbitrary page offset, but its kernel virtual address is aligned 378 * to its size. 379 */ 380 struct folio { 381 /* private: don't document the anon union */ 382 union { 383 struct { 384 /* public: */ 385 unsigned long flags; 386 union { 387 struct list_head lru; 388 /* private: avoid cluttering the output */ 389 struct { 390 void *__filler; 391 /* public: */ 392 unsigned int mlock_count; 393 /* private: */ 394 }; 395 /* public: */ 396 struct dev_pagemap *pgmap; 397 }; 398 struct address_space *mapping; 399 union { 400 pgoff_t index; 401 unsigned long share; 402 }; 403 union { 404 void *private; 405 swp_entry_t swap; 406 }; 407 atomic_t _mapcount; 408 atomic_t _refcount; 409 #ifdef CONFIG_MEMCG 410 unsigned long memcg_data; 411 #elif defined(CONFIG_SLAB_OBJ_EXT) 412 unsigned long _unused_slab_obj_exts; 413 #endif 414 #if defined(WANT_PAGE_VIRTUAL) 415 void *virtual; 416 #endif 417 #ifdef LAST_CPUPID_NOT_IN_PAGE_FLAGS 418 int _last_cpupid; 419 #endif 420 /* private: the union with struct page is transitional */ 421 }; 422 struct page page; 423 }; 424 union { 425 struct { 426 unsigned long _flags_1; 427 unsigned long _head_1; 428 union { 429 struct { 430 /* public: */ 431 atomic_t _large_mapcount; 432 atomic_t _nr_pages_mapped; 433 #ifdef CONFIG_64BIT 434 atomic_t _entire_mapcount; 435 atomic_t _pincount; 436 #endif /* CONFIG_64BIT */ 437 mm_id_mapcount_t _mm_id_mapcount[2]; 438 union { 439 mm_id_t _mm_id[2]; 440 unsigned long _mm_ids; 441 }; 442 /* private: the union with struct page is transitional */ 443 }; 444 unsigned long _usable_1[4]; 445 }; 446 atomic_t _mapcount_1; 447 atomic_t _refcount_1; 448 /* public: */ 449 #ifdef NR_PAGES_IN_LARGE_FOLIO 450 unsigned int _nr_pages; 451 #endif /* NR_PAGES_IN_LARGE_FOLIO */ 452 /* private: the union with struct page is transitional */ 453 }; 454 struct page __page_1; 455 }; 456 union { 457 struct { 458 unsigned long _flags_2; 459 unsigned long _head_2; 460 /* public: */ 461 struct list_head _deferred_list; 462 #ifndef CONFIG_64BIT 463 atomic_t _entire_mapcount; 464 atomic_t _pincount; 465 #endif /* !CONFIG_64BIT */ 466 /* private: the union with struct page is transitional */ 467 }; 468 struct page __page_2; 469 }; 470 union { 471 struct { 472 unsigned long _flags_3; 473 unsigned long _head_3; 474 /* public: */ 475 void *_hugetlb_subpool; 476 void *_hugetlb_cgroup; 477 void *_hugetlb_cgroup_rsvd; 478 void *_hugetlb_hwpoison; 479 /* private: the union with struct page is transitional */ 480 }; 481 struct page __page_3; 482 }; 483 }; 484 485 #define FOLIO_MATCH(pg, fl) \ 486 static_assert(offsetof(struct page, pg) == offsetof(struct folio, fl)) 487 FOLIO_MATCH(flags, flags); 488 FOLIO_MATCH(lru, lru); 489 FOLIO_MATCH(mapping, mapping); 490 FOLIO_MATCH(compound_head, lru); 491 FOLIO_MATCH(__folio_index, index); 492 FOLIO_MATCH(private, private); 493 FOLIO_MATCH(_mapcount, _mapcount); 494 FOLIO_MATCH(_refcount, _refcount); 495 #ifdef CONFIG_MEMCG 496 FOLIO_MATCH(memcg_data, memcg_data); 497 #endif 498 #if defined(WANT_PAGE_VIRTUAL) 499 FOLIO_MATCH(virtual, virtual); 500 #endif 501 #ifdef LAST_CPUPID_NOT_IN_PAGE_FLAGS 502 FOLIO_MATCH(_last_cpupid, _last_cpupid); 503 #endif 504 #undef FOLIO_MATCH 505 #define FOLIO_MATCH(pg, fl) \ 506 static_assert(offsetof(struct folio, fl) == \ 507 offsetof(struct page, pg) + sizeof(struct page)) 508 FOLIO_MATCH(flags, _flags_1); 509 FOLIO_MATCH(compound_head, _head_1); 510 FOLIO_MATCH(_mapcount, _mapcount_1); 511 FOLIO_MATCH(_refcount, _refcount_1); 512 #undef FOLIO_MATCH 513 #define FOLIO_MATCH(pg, fl) \ 514 static_assert(offsetof(struct folio, fl) == \ 515 offsetof(struct page, pg) + 2 * sizeof(struct page)) 516 FOLIO_MATCH(flags, _flags_2); 517 FOLIO_MATCH(compound_head, _head_2); 518 #undef FOLIO_MATCH 519 #define FOLIO_MATCH(pg, fl) \ 520 static_assert(offsetof(struct folio, fl) == \ 521 offsetof(struct page, pg) + 3 * sizeof(struct page)) 522 FOLIO_MATCH(flags, _flags_3); 523 FOLIO_MATCH(compound_head, _head_3); 524 #undef FOLIO_MATCH 525 526 /** 527 * struct ptdesc - Memory descriptor for page tables. 528 * @__page_flags: Same as page flags. Powerpc only. 529 * @pt_rcu_head: For freeing page table pages. 530 * @pt_list: List of used page tables. Used for s390 gmap shadow pages 531 * (which are not linked into the user page tables) and x86 532 * pgds. 533 * @_pt_pad_1: Padding that aliases with page's compound head. 534 * @pmd_huge_pte: Protected by ptdesc->ptl, used for THPs. 535 * @__page_mapping: Aliases with page->mapping. Unused for page tables. 536 * @pt_index: Used for s390 gmap. 537 * @pt_mm: Used for x86 pgds. 538 * @pt_frag_refcount: For fragmented page table tracking. Powerpc only. 539 * @pt_share_count: Used for HugeTLB PMD page table share count. 540 * @_pt_pad_2: Padding to ensure proper alignment. 541 * @ptl: Lock for the page table. 542 * @__page_type: Same as page->page_type. Unused for page tables. 543 * @__page_refcount: Same as page refcount. 544 * @pt_memcg_data: Memcg data. Tracked for page tables here. 545 * 546 * This struct overlays struct page for now. Do not modify without a good 547 * understanding of the issues. 548 */ 549 struct ptdesc { 550 unsigned long __page_flags; 551 552 union { 553 struct rcu_head pt_rcu_head; 554 struct list_head pt_list; 555 struct { 556 unsigned long _pt_pad_1; 557 pgtable_t pmd_huge_pte; 558 }; 559 }; 560 unsigned long __page_mapping; 561 562 union { 563 pgoff_t pt_index; 564 struct mm_struct *pt_mm; 565 atomic_t pt_frag_refcount; 566 #ifdef CONFIG_HUGETLB_PMD_PAGE_TABLE_SHARING 567 atomic_t pt_share_count; 568 #endif 569 }; 570 571 union { 572 unsigned long _pt_pad_2; 573 #if ALLOC_SPLIT_PTLOCKS 574 spinlock_t *ptl; 575 #else 576 spinlock_t ptl; 577 #endif 578 }; 579 unsigned int __page_type; 580 atomic_t __page_refcount; 581 #ifdef CONFIG_MEMCG 582 unsigned long pt_memcg_data; 583 #endif 584 }; 585 586 #define TABLE_MATCH(pg, pt) \ 587 static_assert(offsetof(struct page, pg) == offsetof(struct ptdesc, pt)) 588 TABLE_MATCH(flags, __page_flags); 589 TABLE_MATCH(compound_head, pt_list); 590 TABLE_MATCH(compound_head, _pt_pad_1); 591 TABLE_MATCH(mapping, __page_mapping); 592 TABLE_MATCH(__folio_index, pt_index); 593 TABLE_MATCH(rcu_head, pt_rcu_head); 594 TABLE_MATCH(page_type, __page_type); 595 TABLE_MATCH(_refcount, __page_refcount); 596 #ifdef CONFIG_MEMCG 597 TABLE_MATCH(memcg_data, pt_memcg_data); 598 #endif 599 #undef TABLE_MATCH 600 static_assert(sizeof(struct ptdesc) <= sizeof(struct page)); 601 602 #define ptdesc_page(pt) (_Generic((pt), \ 603 const struct ptdesc *: (const struct page *)(pt), \ 604 struct ptdesc *: (struct page *)(pt))) 605 606 #define ptdesc_folio(pt) (_Generic((pt), \ 607 const struct ptdesc *: (const struct folio *)(pt), \ 608 struct ptdesc *: (struct folio *)(pt))) 609 610 #define page_ptdesc(p) (_Generic((p), \ 611 const struct page *: (const struct ptdesc *)(p), \ 612 struct page *: (struct ptdesc *)(p))) 613 614 #ifdef CONFIG_HUGETLB_PMD_PAGE_TABLE_SHARING 615 static inline void ptdesc_pmd_pts_init(struct ptdesc *ptdesc) 616 { 617 atomic_set(&ptdesc->pt_share_count, 0); 618 } 619 620 static inline void ptdesc_pmd_pts_inc(struct ptdesc *ptdesc) 621 { 622 atomic_inc(&ptdesc->pt_share_count); 623 } 624 625 static inline void ptdesc_pmd_pts_dec(struct ptdesc *ptdesc) 626 { 627 atomic_dec(&ptdesc->pt_share_count); 628 } 629 630 static inline int ptdesc_pmd_pts_count(struct ptdesc *ptdesc) 631 { 632 return atomic_read(&ptdesc->pt_share_count); 633 } 634 #else 635 static inline void ptdesc_pmd_pts_init(struct ptdesc *ptdesc) 636 { 637 } 638 #endif 639 640 /* 641 * Used for sizing the vmemmap region on some architectures 642 */ 643 #define STRUCT_PAGE_MAX_SHIFT (order_base_2(sizeof(struct page))) 644 645 /* 646 * page_private can be used on tail pages. However, PagePrivate is only 647 * checked by the VM on the head page. So page_private on the tail pages 648 * should be used for data that's ancillary to the head page (eg attaching 649 * buffer heads to tail pages after attaching buffer heads to the head page) 650 */ 651 #define page_private(page) ((page)->private) 652 653 static inline void set_page_private(struct page *page, unsigned long private) 654 { 655 page->private = private; 656 } 657 658 static inline void *folio_get_private(struct folio *folio) 659 { 660 return folio->private; 661 } 662 663 typedef unsigned long vm_flags_t; 664 665 /* 666 * freeptr_t represents a SLUB freelist pointer, which might be encoded 667 * and not dereferenceable if CONFIG_SLAB_FREELIST_HARDENED is enabled. 668 */ 669 typedef struct { unsigned long v; } freeptr_t; 670 671 /* 672 * A region containing a mapping of a non-memory backed file under NOMMU 673 * conditions. These are held in a global tree and are pinned by the VMAs that 674 * map parts of them. 675 */ 676 struct vm_region { 677 struct rb_node vm_rb; /* link in global region tree */ 678 vm_flags_t vm_flags; /* VMA vm_flags */ 679 unsigned long vm_start; /* start address of region */ 680 unsigned long vm_end; /* region initialised to here */ 681 unsigned long vm_top; /* region allocated to here */ 682 unsigned long vm_pgoff; /* the offset in vm_file corresponding to vm_start */ 683 struct file *vm_file; /* the backing file or NULL */ 684 685 int vm_usage; /* region usage count (access under nommu_region_sem) */ 686 bool vm_icache_flushed : 1; /* true if the icache has been flushed for 687 * this region */ 688 }; 689 690 #ifdef CONFIG_USERFAULTFD 691 #define NULL_VM_UFFD_CTX ((struct vm_userfaultfd_ctx) { NULL, }) 692 struct vm_userfaultfd_ctx { 693 struct userfaultfd_ctx *ctx; 694 }; 695 #else /* CONFIG_USERFAULTFD */ 696 #define NULL_VM_UFFD_CTX ((struct vm_userfaultfd_ctx) {}) 697 struct vm_userfaultfd_ctx {}; 698 #endif /* CONFIG_USERFAULTFD */ 699 700 struct anon_vma_name { 701 struct kref kref; 702 /* The name needs to be at the end because it is dynamically sized. */ 703 char name[]; 704 }; 705 706 #ifdef CONFIG_ANON_VMA_NAME 707 /* 708 * mmap_lock should be read-locked when calling anon_vma_name(). Caller should 709 * either keep holding the lock while using the returned pointer or it should 710 * raise anon_vma_name refcount before releasing the lock. 711 */ 712 struct anon_vma_name *anon_vma_name(struct vm_area_struct *vma); 713 struct anon_vma_name *anon_vma_name_alloc(const char *name); 714 void anon_vma_name_free(struct kref *kref); 715 #else /* CONFIG_ANON_VMA_NAME */ 716 static inline struct anon_vma_name *anon_vma_name(struct vm_area_struct *vma) 717 { 718 return NULL; 719 } 720 721 static inline struct anon_vma_name *anon_vma_name_alloc(const char *name) 722 { 723 return NULL; 724 } 725 #endif 726 727 #define VMA_LOCK_OFFSET 0x40000000 728 #define VMA_REF_LIMIT (VMA_LOCK_OFFSET - 1) 729 730 struct vma_numab_state { 731 /* 732 * Initialised as time in 'jiffies' after which VMA 733 * should be scanned. Delays first scan of new VMA by at 734 * least sysctl_numa_balancing_scan_delay: 735 */ 736 unsigned long next_scan; 737 738 /* 739 * Time in jiffies when pids_active[] is reset to 740 * detect phase change behaviour: 741 */ 742 unsigned long pids_active_reset; 743 744 /* 745 * Approximate tracking of PIDs that trapped a NUMA hinting 746 * fault. May produce false positives due to hash collisions. 747 * 748 * [0] Previous PID tracking 749 * [1] Current PID tracking 750 * 751 * Window moves after next_pid_reset has expired approximately 752 * every VMA_PID_RESET_PERIOD jiffies: 753 */ 754 unsigned long pids_active[2]; 755 756 /* MM scan sequence ID when scan first started after VMA creation */ 757 int start_scan_seq; 758 759 /* 760 * MM scan sequence ID when the VMA was last completely scanned. 761 * A VMA is not eligible for scanning if prev_scan_seq == numa_scan_seq 762 */ 763 int prev_scan_seq; 764 }; 765 766 #ifdef __HAVE_PFNMAP_TRACKING 767 struct pfnmap_track_ctx { 768 struct kref kref; 769 unsigned long pfn; 770 unsigned long size; /* in bytes */ 771 }; 772 #endif 773 774 /* 775 * Describes a VMA that is about to be mmap()'ed. Drivers may choose to 776 * manipulate mutable fields which will cause those fields to be updated in the 777 * resultant VMA. 778 * 779 * Helper functions are not required for manipulating any field. 780 */ 781 struct vm_area_desc { 782 /* Immutable state. */ 783 struct mm_struct *mm; 784 unsigned long start; 785 unsigned long end; 786 787 /* Mutable fields. Populated with initial state. */ 788 pgoff_t pgoff; 789 struct file *file; 790 vm_flags_t vm_flags; 791 pgprot_t page_prot; 792 793 /* Write-only fields. */ 794 const struct vm_operations_struct *vm_ops; 795 void *private_data; 796 }; 797 798 /* 799 * This struct describes a virtual memory area. There is one of these 800 * per VM-area/task. A VM area is any part of the process virtual memory 801 * space that has a special rule for the page-fault handlers (ie a shared 802 * library, the executable area etc). 803 * 804 * Only explicitly marked struct members may be accessed by RCU readers before 805 * getting a stable reference. 806 * 807 * WARNING: when adding new members, please update vm_area_init_from() to copy 808 * them during vm_area_struct content duplication. 809 */ 810 struct vm_area_struct { 811 /* The first cache line has the info for VMA tree walking. */ 812 813 union { 814 struct { 815 /* VMA covers [vm_start; vm_end) addresses within mm */ 816 unsigned long vm_start; 817 unsigned long vm_end; 818 }; 819 freeptr_t vm_freeptr; /* Pointer used by SLAB_TYPESAFE_BY_RCU */ 820 }; 821 822 /* 823 * The address space we belong to. 824 * Unstable RCU readers are allowed to read this. 825 */ 826 struct mm_struct *vm_mm; 827 pgprot_t vm_page_prot; /* Access permissions of this VMA. */ 828 829 /* 830 * Flags, see mm.h. 831 * To modify use vm_flags_{init|reset|set|clear|mod} functions. 832 */ 833 union { 834 const vm_flags_t vm_flags; 835 vm_flags_t __private __vm_flags; 836 }; 837 838 #ifdef CONFIG_PER_VMA_LOCK 839 /* 840 * Can only be written (using WRITE_ONCE()) while holding both: 841 * - mmap_lock (in write mode) 842 * - vm_refcnt bit at VMA_LOCK_OFFSET is set 843 * Can be read reliably while holding one of: 844 * - mmap_lock (in read or write mode) 845 * - vm_refcnt bit at VMA_LOCK_OFFSET is set or vm_refcnt > 1 846 * Can be read unreliably (using READ_ONCE()) for pessimistic bailout 847 * while holding nothing (except RCU to keep the VMA struct allocated). 848 * 849 * This sequence counter is explicitly allowed to overflow; sequence 850 * counter reuse can only lead to occasional unnecessary use of the 851 * slowpath. 852 */ 853 unsigned int vm_lock_seq; 854 #endif 855 /* 856 * A file's MAP_PRIVATE vma can be in both i_mmap tree and anon_vma 857 * list, after a COW of one of the file pages. A MAP_SHARED vma 858 * can only be in the i_mmap tree. An anonymous MAP_PRIVATE, stack 859 * or brk vma (with NULL file) can only be in an anon_vma list. 860 */ 861 struct list_head anon_vma_chain; /* Serialized by mmap_lock & 862 * page_table_lock */ 863 struct anon_vma *anon_vma; /* Serialized by page_table_lock */ 864 865 /* Function pointers to deal with this struct. */ 866 const struct vm_operations_struct *vm_ops; 867 868 /* Information about our backing store: */ 869 unsigned long vm_pgoff; /* Offset (within vm_file) in PAGE_SIZE 870 units */ 871 struct file * vm_file; /* File we map to (can be NULL). */ 872 void * vm_private_data; /* was vm_pte (shared mem) */ 873 874 #ifdef CONFIG_SWAP 875 atomic_long_t swap_readahead_info; 876 #endif 877 #ifndef CONFIG_MMU 878 struct vm_region *vm_region; /* NOMMU mapping region */ 879 #endif 880 #ifdef CONFIG_NUMA 881 struct mempolicy *vm_policy; /* NUMA policy for the VMA */ 882 #endif 883 #ifdef CONFIG_NUMA_BALANCING 884 struct vma_numab_state *numab_state; /* NUMA Balancing state */ 885 #endif 886 #ifdef CONFIG_PER_VMA_LOCK 887 /* Unstable RCU readers are allowed to read this. */ 888 refcount_t vm_refcnt ____cacheline_aligned_in_smp; 889 #ifdef CONFIG_DEBUG_LOCK_ALLOC 890 struct lockdep_map vmlock_dep_map; 891 #endif 892 #endif 893 /* 894 * For areas with an address space and backing store, 895 * linkage into the address_space->i_mmap interval tree. 896 * 897 */ 898 struct { 899 struct rb_node rb; 900 unsigned long rb_subtree_last; 901 } shared; 902 #ifdef CONFIG_ANON_VMA_NAME 903 /* 904 * For private and shared anonymous mappings, a pointer to a null 905 * terminated string containing the name given to the vma, or NULL if 906 * unnamed. Serialized by mmap_lock. Use anon_vma_name to access. 907 */ 908 struct anon_vma_name *anon_name; 909 #endif 910 struct vm_userfaultfd_ctx vm_userfaultfd_ctx; 911 #ifdef __HAVE_PFNMAP_TRACKING 912 struct pfnmap_track_ctx *pfnmap_track_ctx; 913 #endif 914 } __randomize_layout; 915 916 #ifdef CONFIG_NUMA 917 #define vma_policy(vma) ((vma)->vm_policy) 918 #else 919 #define vma_policy(vma) NULL 920 #endif 921 922 #ifdef CONFIG_SCHED_MM_CID 923 struct mm_cid { 924 u64 time; 925 int cid; 926 int recent_cid; 927 }; 928 #endif 929 930 struct kioctx_table; 931 struct iommu_mm_data; 932 struct mm_struct { 933 struct { 934 /* 935 * Fields which are often written to are placed in a separate 936 * cache line. 937 */ 938 struct { 939 /** 940 * @mm_count: The number of references to &struct 941 * mm_struct (@mm_users count as 1). 942 * 943 * Use mmgrab()/mmdrop() to modify. When this drops to 944 * 0, the &struct mm_struct is freed. 945 */ 946 atomic_t mm_count; 947 } ____cacheline_aligned_in_smp; 948 949 struct maple_tree mm_mt; 950 951 unsigned long mmap_base; /* base of mmap area */ 952 unsigned long mmap_legacy_base; /* base of mmap area in bottom-up allocations */ 953 #ifdef CONFIG_HAVE_ARCH_COMPAT_MMAP_BASES 954 /* Base addresses for compatible mmap() */ 955 unsigned long mmap_compat_base; 956 unsigned long mmap_compat_legacy_base; 957 #endif 958 unsigned long task_size; /* size of task vm space */ 959 pgd_t * pgd; 960 961 #ifdef CONFIG_MEMBARRIER 962 /** 963 * @membarrier_state: Flags controlling membarrier behavior. 964 * 965 * This field is close to @pgd to hopefully fit in the same 966 * cache-line, which needs to be touched by switch_mm(). 967 */ 968 atomic_t membarrier_state; 969 #endif 970 971 /** 972 * @mm_users: The number of users including userspace. 973 * 974 * Use mmget()/mmget_not_zero()/mmput() to modify. When this 975 * drops to 0 (i.e. when the task exits and there are no other 976 * temporary reference holders), we also release a reference on 977 * @mm_count (which may then free the &struct mm_struct if 978 * @mm_count also drops to 0). 979 */ 980 atomic_t mm_users; 981 982 #ifdef CONFIG_SCHED_MM_CID 983 /** 984 * @pcpu_cid: Per-cpu current cid. 985 * 986 * Keep track of the currently allocated mm_cid for each cpu. 987 * The per-cpu mm_cid values are serialized by their respective 988 * runqueue locks. 989 */ 990 struct mm_cid __percpu *pcpu_cid; 991 /* 992 * @mm_cid_next_scan: Next mm_cid scan (in jiffies). 993 * 994 * When the next mm_cid scan is due (in jiffies). 995 */ 996 unsigned long mm_cid_next_scan; 997 /** 998 * @nr_cpus_allowed: Number of CPUs allowed for mm. 999 * 1000 * Number of CPUs allowed in the union of all mm's 1001 * threads allowed CPUs. 1002 */ 1003 unsigned int nr_cpus_allowed; 1004 /** 1005 * @max_nr_cid: Maximum number of allowed concurrency 1006 * IDs allocated. 1007 * 1008 * Track the highest number of allowed concurrency IDs 1009 * allocated for the mm. 1010 */ 1011 atomic_t max_nr_cid; 1012 /** 1013 * @cpus_allowed_lock: Lock protecting mm cpus_allowed. 1014 * 1015 * Provide mutual exclusion for mm cpus_allowed and 1016 * mm nr_cpus_allowed updates. 1017 */ 1018 raw_spinlock_t cpus_allowed_lock; 1019 #endif 1020 #ifdef CONFIG_MMU 1021 atomic_long_t pgtables_bytes; /* size of all page tables */ 1022 #endif 1023 int map_count; /* number of VMAs */ 1024 1025 spinlock_t page_table_lock; /* Protects page tables and some 1026 * counters 1027 */ 1028 /* 1029 * With some kernel config, the current mmap_lock's offset 1030 * inside 'mm_struct' is at 0x120, which is very optimal, as 1031 * its two hot fields 'count' and 'owner' sit in 2 different 1032 * cachelines, and when mmap_lock is highly contended, both 1033 * of the 2 fields will be accessed frequently, current layout 1034 * will help to reduce cache bouncing. 1035 * 1036 * So please be careful with adding new fields before 1037 * mmap_lock, which can easily push the 2 fields into one 1038 * cacheline. 1039 */ 1040 struct rw_semaphore mmap_lock; 1041 1042 struct list_head mmlist; /* List of maybe swapped mm's. These 1043 * are globally strung together off 1044 * init_mm.mmlist, and are protected 1045 * by mmlist_lock 1046 */ 1047 #ifdef CONFIG_PER_VMA_LOCK 1048 struct rcuwait vma_writer_wait; 1049 /* 1050 * This field has lock-like semantics, meaning it is sometimes 1051 * accessed with ACQUIRE/RELEASE semantics. 1052 * Roughly speaking, incrementing the sequence number is 1053 * equivalent to releasing locks on VMAs; reading the sequence 1054 * number can be part of taking a read lock on a VMA. 1055 * Incremented every time mmap_lock is write-locked/unlocked. 1056 * Initialized to 0, therefore odd values indicate mmap_lock 1057 * is write-locked and even values that it's released. 1058 * 1059 * Can be modified under write mmap_lock using RELEASE 1060 * semantics. 1061 * Can be read with no other protection when holding write 1062 * mmap_lock. 1063 * Can be read with ACQUIRE semantics if not holding write 1064 * mmap_lock. 1065 */ 1066 seqcount_t mm_lock_seq; 1067 #endif 1068 #ifdef CONFIG_FUTEX_PRIVATE_HASH 1069 struct mutex futex_hash_lock; 1070 struct futex_private_hash __rcu *futex_phash; 1071 struct futex_private_hash *futex_phash_new; 1072 /* futex-ref */ 1073 unsigned long futex_batches; 1074 struct rcu_head futex_rcu; 1075 atomic_long_t futex_atomic; 1076 unsigned int __percpu *futex_ref; 1077 #endif 1078 1079 unsigned long hiwater_rss; /* High-watermark of RSS usage */ 1080 unsigned long hiwater_vm; /* High-water virtual memory usage */ 1081 1082 unsigned long total_vm; /* Total pages mapped */ 1083 unsigned long locked_vm; /* Pages that have PG_mlocked set */ 1084 atomic64_t pinned_vm; /* Refcount permanently increased */ 1085 unsigned long data_vm; /* VM_WRITE & ~VM_SHARED & ~VM_STACK */ 1086 unsigned long exec_vm; /* VM_EXEC & ~VM_WRITE & ~VM_STACK */ 1087 unsigned long stack_vm; /* VM_STACK */ 1088 vm_flags_t def_flags; 1089 1090 /** 1091 * @write_protect_seq: Locked when any thread is write 1092 * protecting pages mapped by this mm to enforce a later COW, 1093 * for instance during page table copying for fork(). 1094 */ 1095 seqcount_t write_protect_seq; 1096 1097 spinlock_t arg_lock; /* protect the below fields */ 1098 1099 unsigned long start_code, end_code, start_data, end_data; 1100 unsigned long start_brk, brk, start_stack; 1101 unsigned long arg_start, arg_end, env_start, env_end; 1102 1103 unsigned long saved_auxv[AT_VECTOR_SIZE]; /* for /proc/PID/auxv */ 1104 1105 struct percpu_counter rss_stat[NR_MM_COUNTERS]; 1106 1107 struct linux_binfmt *binfmt; 1108 1109 /* Architecture-specific MM context */ 1110 mm_context_t context; 1111 1112 unsigned long flags; /* Must use atomic bitops to access */ 1113 1114 #ifdef CONFIG_AIO 1115 spinlock_t ioctx_lock; 1116 struct kioctx_table __rcu *ioctx_table; 1117 #endif 1118 #ifdef CONFIG_MEMCG 1119 /* 1120 * "owner" points to a task that is regarded as the canonical 1121 * user/owner of this mm. All of the following must be true in 1122 * order for it to be changed: 1123 * 1124 * current == mm->owner 1125 * current->mm != mm 1126 * new_owner->mm == mm 1127 * new_owner->alloc_lock is held 1128 */ 1129 struct task_struct __rcu *owner; 1130 #endif 1131 struct user_namespace *user_ns; 1132 1133 /* store ref to file /proc/<pid>/exe symlink points to */ 1134 struct file __rcu *exe_file; 1135 #ifdef CONFIG_MMU_NOTIFIER 1136 struct mmu_notifier_subscriptions *notifier_subscriptions; 1137 #endif 1138 #if defined(CONFIG_TRANSPARENT_HUGEPAGE) && !defined(CONFIG_SPLIT_PMD_PTLOCKS) 1139 pgtable_t pmd_huge_pte; /* protected by page_table_lock */ 1140 #endif 1141 #ifdef CONFIG_NUMA_BALANCING 1142 /* 1143 * numa_next_scan is the next time that PTEs will be remapped 1144 * PROT_NONE to trigger NUMA hinting faults; such faults gather 1145 * statistics and migrate pages to new nodes if necessary. 1146 */ 1147 unsigned long numa_next_scan; 1148 1149 /* Restart point for scanning and remapping PTEs. */ 1150 unsigned long numa_scan_offset; 1151 1152 /* numa_scan_seq prevents two threads remapping PTEs. */ 1153 int numa_scan_seq; 1154 #endif 1155 /* 1156 * An operation with batched TLB flushing is going on. Anything 1157 * that can move process memory needs to flush the TLB when 1158 * moving a PROT_NONE mapped page. 1159 */ 1160 atomic_t tlb_flush_pending; 1161 #ifdef CONFIG_ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH 1162 /* See flush_tlb_batched_pending() */ 1163 atomic_t tlb_flush_batched; 1164 #endif 1165 struct uprobes_state uprobes_state; 1166 #ifdef CONFIG_PREEMPT_RT 1167 struct rcu_head delayed_drop; 1168 #endif 1169 #ifdef CONFIG_HUGETLB_PAGE 1170 atomic_long_t hugetlb_usage; 1171 #endif 1172 struct work_struct async_put_work; 1173 1174 #ifdef CONFIG_IOMMU_MM_DATA 1175 struct iommu_mm_data *iommu_mm; 1176 #endif 1177 #ifdef CONFIG_KSM 1178 /* 1179 * Represent how many pages of this process are involved in KSM 1180 * merging (not including ksm_zero_pages). 1181 */ 1182 unsigned long ksm_merging_pages; 1183 /* 1184 * Represent how many pages are checked for ksm merging 1185 * including merged and not merged. 1186 */ 1187 unsigned long ksm_rmap_items; 1188 /* 1189 * Represent how many empty pages are merged with kernel zero 1190 * pages when enabling KSM use_zero_pages. 1191 */ 1192 atomic_long_t ksm_zero_pages; 1193 #endif /* CONFIG_KSM */ 1194 #ifdef CONFIG_LRU_GEN_WALKS_MMU 1195 struct { 1196 /* this mm_struct is on lru_gen_mm_list */ 1197 struct list_head list; 1198 /* 1199 * Set when switching to this mm_struct, as a hint of 1200 * whether it has been used since the last time per-node 1201 * page table walkers cleared the corresponding bits. 1202 */ 1203 unsigned long bitmap; 1204 #ifdef CONFIG_MEMCG 1205 /* points to the memcg of "owner" above */ 1206 struct mem_cgroup *memcg; 1207 #endif 1208 } lru_gen; 1209 #endif /* CONFIG_LRU_GEN_WALKS_MMU */ 1210 #ifdef CONFIG_MM_ID 1211 mm_id_t mm_id; 1212 #endif /* CONFIG_MM_ID */ 1213 } __randomize_layout; 1214 1215 /* 1216 * The mm_cpumask needs to be at the end of mm_struct, because it 1217 * is dynamically sized based on nr_cpu_ids. 1218 */ 1219 unsigned long cpu_bitmap[]; 1220 }; 1221 1222 #define MM_MT_FLAGS (MT_FLAGS_ALLOC_RANGE | MT_FLAGS_LOCK_EXTERN | \ 1223 MT_FLAGS_USE_RCU) 1224 extern struct mm_struct init_mm; 1225 1226 /* Pointer magic because the dynamic array size confuses some compilers. */ 1227 static inline void mm_init_cpumask(struct mm_struct *mm) 1228 { 1229 unsigned long cpu_bitmap = (unsigned long)mm; 1230 1231 cpu_bitmap += offsetof(struct mm_struct, cpu_bitmap); 1232 cpumask_clear((struct cpumask *)cpu_bitmap); 1233 } 1234 1235 /* Future-safe accessor for struct mm_struct's cpu_vm_mask. */ 1236 static inline cpumask_t *mm_cpumask(struct mm_struct *mm) 1237 { 1238 return (struct cpumask *)&mm->cpu_bitmap; 1239 } 1240 1241 #ifdef CONFIG_LRU_GEN 1242 1243 struct lru_gen_mm_list { 1244 /* mm_struct list for page table walkers */ 1245 struct list_head fifo; 1246 /* protects the list above */ 1247 spinlock_t lock; 1248 }; 1249 1250 #endif /* CONFIG_LRU_GEN */ 1251 1252 #ifdef CONFIG_LRU_GEN_WALKS_MMU 1253 1254 void lru_gen_add_mm(struct mm_struct *mm); 1255 void lru_gen_del_mm(struct mm_struct *mm); 1256 void lru_gen_migrate_mm(struct mm_struct *mm); 1257 1258 static inline void lru_gen_init_mm(struct mm_struct *mm) 1259 { 1260 INIT_LIST_HEAD(&mm->lru_gen.list); 1261 mm->lru_gen.bitmap = 0; 1262 #ifdef CONFIG_MEMCG 1263 mm->lru_gen.memcg = NULL; 1264 #endif 1265 } 1266 1267 static inline void lru_gen_use_mm(struct mm_struct *mm) 1268 { 1269 /* 1270 * When the bitmap is set, page reclaim knows this mm_struct has been 1271 * used since the last time it cleared the bitmap. So it might be worth 1272 * walking the page tables of this mm_struct to clear the accessed bit. 1273 */ 1274 WRITE_ONCE(mm->lru_gen.bitmap, -1); 1275 } 1276 1277 #else /* !CONFIG_LRU_GEN_WALKS_MMU */ 1278 1279 static inline void lru_gen_add_mm(struct mm_struct *mm) 1280 { 1281 } 1282 1283 static inline void lru_gen_del_mm(struct mm_struct *mm) 1284 { 1285 } 1286 1287 static inline void lru_gen_migrate_mm(struct mm_struct *mm) 1288 { 1289 } 1290 1291 static inline void lru_gen_init_mm(struct mm_struct *mm) 1292 { 1293 } 1294 1295 static inline void lru_gen_use_mm(struct mm_struct *mm) 1296 { 1297 } 1298 1299 #endif /* CONFIG_LRU_GEN_WALKS_MMU */ 1300 1301 struct vma_iterator { 1302 struct ma_state mas; 1303 }; 1304 1305 #define VMA_ITERATOR(name, __mm, __addr) \ 1306 struct vma_iterator name = { \ 1307 .mas = { \ 1308 .tree = &(__mm)->mm_mt, \ 1309 .index = __addr, \ 1310 .node = NULL, \ 1311 .status = ma_start, \ 1312 }, \ 1313 } 1314 1315 static inline void vma_iter_init(struct vma_iterator *vmi, 1316 struct mm_struct *mm, unsigned long addr) 1317 { 1318 mas_init(&vmi->mas, &mm->mm_mt, addr); 1319 } 1320 1321 #ifdef CONFIG_SCHED_MM_CID 1322 1323 enum mm_cid_state { 1324 MM_CID_UNSET = -1U, /* Unset state has lazy_put flag set. */ 1325 MM_CID_LAZY_PUT = (1U << 31), 1326 }; 1327 1328 static inline bool mm_cid_is_unset(int cid) 1329 { 1330 return cid == MM_CID_UNSET; 1331 } 1332 1333 static inline bool mm_cid_is_lazy_put(int cid) 1334 { 1335 return !mm_cid_is_unset(cid) && (cid & MM_CID_LAZY_PUT); 1336 } 1337 1338 static inline bool mm_cid_is_valid(int cid) 1339 { 1340 return !(cid & MM_CID_LAZY_PUT); 1341 } 1342 1343 static inline int mm_cid_set_lazy_put(int cid) 1344 { 1345 return cid | MM_CID_LAZY_PUT; 1346 } 1347 1348 static inline int mm_cid_clear_lazy_put(int cid) 1349 { 1350 return cid & ~MM_CID_LAZY_PUT; 1351 } 1352 1353 /* 1354 * mm_cpus_allowed: Union of all mm's threads allowed CPUs. 1355 */ 1356 static inline cpumask_t *mm_cpus_allowed(struct mm_struct *mm) 1357 { 1358 unsigned long bitmap = (unsigned long)mm; 1359 1360 bitmap += offsetof(struct mm_struct, cpu_bitmap); 1361 /* Skip cpu_bitmap */ 1362 bitmap += cpumask_size(); 1363 return (struct cpumask *)bitmap; 1364 } 1365 1366 /* Accessor for struct mm_struct's cidmask. */ 1367 static inline cpumask_t *mm_cidmask(struct mm_struct *mm) 1368 { 1369 unsigned long cid_bitmap = (unsigned long)mm_cpus_allowed(mm); 1370 1371 /* Skip mm_cpus_allowed */ 1372 cid_bitmap += cpumask_size(); 1373 return (struct cpumask *)cid_bitmap; 1374 } 1375 1376 static inline void mm_init_cid(struct mm_struct *mm, struct task_struct *p) 1377 { 1378 int i; 1379 1380 for_each_possible_cpu(i) { 1381 struct mm_cid *pcpu_cid = per_cpu_ptr(mm->pcpu_cid, i); 1382 1383 pcpu_cid->cid = MM_CID_UNSET; 1384 pcpu_cid->recent_cid = MM_CID_UNSET; 1385 pcpu_cid->time = 0; 1386 } 1387 mm->nr_cpus_allowed = p->nr_cpus_allowed; 1388 atomic_set(&mm->max_nr_cid, 0); 1389 raw_spin_lock_init(&mm->cpus_allowed_lock); 1390 cpumask_copy(mm_cpus_allowed(mm), &p->cpus_mask); 1391 cpumask_clear(mm_cidmask(mm)); 1392 } 1393 1394 static inline int mm_alloc_cid_noprof(struct mm_struct *mm, struct task_struct *p) 1395 { 1396 mm->pcpu_cid = alloc_percpu_noprof(struct mm_cid); 1397 if (!mm->pcpu_cid) 1398 return -ENOMEM; 1399 mm_init_cid(mm, p); 1400 return 0; 1401 } 1402 #define mm_alloc_cid(...) alloc_hooks(mm_alloc_cid_noprof(__VA_ARGS__)) 1403 1404 static inline void mm_destroy_cid(struct mm_struct *mm) 1405 { 1406 free_percpu(mm->pcpu_cid); 1407 mm->pcpu_cid = NULL; 1408 } 1409 1410 static inline unsigned int mm_cid_size(void) 1411 { 1412 return 2 * cpumask_size(); /* mm_cpus_allowed(), mm_cidmask(). */ 1413 } 1414 1415 static inline void mm_set_cpus_allowed(struct mm_struct *mm, const struct cpumask *cpumask) 1416 { 1417 struct cpumask *mm_allowed = mm_cpus_allowed(mm); 1418 1419 if (!mm) 1420 return; 1421 /* The mm_cpus_allowed is the union of each thread allowed CPUs masks. */ 1422 raw_spin_lock(&mm->cpus_allowed_lock); 1423 cpumask_or(mm_allowed, mm_allowed, cpumask); 1424 WRITE_ONCE(mm->nr_cpus_allowed, cpumask_weight(mm_allowed)); 1425 raw_spin_unlock(&mm->cpus_allowed_lock); 1426 } 1427 #else /* CONFIG_SCHED_MM_CID */ 1428 static inline void mm_init_cid(struct mm_struct *mm, struct task_struct *p) { } 1429 static inline int mm_alloc_cid(struct mm_struct *mm, struct task_struct *p) { return 0; } 1430 static inline void mm_destroy_cid(struct mm_struct *mm) { } 1431 1432 static inline unsigned int mm_cid_size(void) 1433 { 1434 return 0; 1435 } 1436 static inline void mm_set_cpus_allowed(struct mm_struct *mm, const struct cpumask *cpumask) { } 1437 #endif /* CONFIG_SCHED_MM_CID */ 1438 1439 struct mmu_gather; 1440 extern void tlb_gather_mmu(struct mmu_gather *tlb, struct mm_struct *mm); 1441 extern void tlb_gather_mmu_fullmm(struct mmu_gather *tlb, struct mm_struct *mm); 1442 extern void tlb_finish_mmu(struct mmu_gather *tlb); 1443 1444 struct vm_fault; 1445 1446 /** 1447 * typedef vm_fault_t - Return type for page fault handlers. 1448 * 1449 * Page fault handlers return a bitmask of %VM_FAULT values. 1450 */ 1451 typedef __bitwise unsigned int vm_fault_t; 1452 1453 /** 1454 * enum vm_fault_reason - Page fault handlers return a bitmask of 1455 * these values to tell the core VM what happened when handling the 1456 * fault. Used to decide whether a process gets delivered SIGBUS or 1457 * just gets major/minor fault counters bumped up. 1458 * 1459 * @VM_FAULT_OOM: Out Of Memory 1460 * @VM_FAULT_SIGBUS: Bad access 1461 * @VM_FAULT_MAJOR: Page read from storage 1462 * @VM_FAULT_HWPOISON: Hit poisoned small page 1463 * @VM_FAULT_HWPOISON_LARGE: Hit poisoned large page. Index encoded 1464 * in upper bits 1465 * @VM_FAULT_SIGSEGV: segmentation fault 1466 * @VM_FAULT_NOPAGE: ->fault installed the pte, not return page 1467 * @VM_FAULT_LOCKED: ->fault locked the returned page 1468 * @VM_FAULT_RETRY: ->fault blocked, must retry 1469 * @VM_FAULT_FALLBACK: huge page fault failed, fall back to small 1470 * @VM_FAULT_DONE_COW: ->fault has fully handled COW 1471 * @VM_FAULT_NEEDDSYNC: ->fault did not modify page tables and needs 1472 * fsync() to complete (for synchronous page faults 1473 * in DAX) 1474 * @VM_FAULT_COMPLETED: ->fault completed, meanwhile mmap lock released 1475 * @VM_FAULT_HINDEX_MASK: mask HINDEX value 1476 * 1477 */ 1478 enum vm_fault_reason { 1479 VM_FAULT_OOM = (__force vm_fault_t)0x000001, 1480 VM_FAULT_SIGBUS = (__force vm_fault_t)0x000002, 1481 VM_FAULT_MAJOR = (__force vm_fault_t)0x000004, 1482 VM_FAULT_HWPOISON = (__force vm_fault_t)0x000010, 1483 VM_FAULT_HWPOISON_LARGE = (__force vm_fault_t)0x000020, 1484 VM_FAULT_SIGSEGV = (__force vm_fault_t)0x000040, 1485 VM_FAULT_NOPAGE = (__force vm_fault_t)0x000100, 1486 VM_FAULT_LOCKED = (__force vm_fault_t)0x000200, 1487 VM_FAULT_RETRY = (__force vm_fault_t)0x000400, 1488 VM_FAULT_FALLBACK = (__force vm_fault_t)0x000800, 1489 VM_FAULT_DONE_COW = (__force vm_fault_t)0x001000, 1490 VM_FAULT_NEEDDSYNC = (__force vm_fault_t)0x002000, 1491 VM_FAULT_COMPLETED = (__force vm_fault_t)0x004000, 1492 VM_FAULT_HINDEX_MASK = (__force vm_fault_t)0x0f0000, 1493 }; 1494 1495 /* Encode hstate index for a hwpoisoned large page */ 1496 #define VM_FAULT_SET_HINDEX(x) ((__force vm_fault_t)((x) << 16)) 1497 #define VM_FAULT_GET_HINDEX(x) (((__force unsigned int)(x) >> 16) & 0xf) 1498 1499 #define VM_FAULT_ERROR (VM_FAULT_OOM | VM_FAULT_SIGBUS | \ 1500 VM_FAULT_SIGSEGV | VM_FAULT_HWPOISON | \ 1501 VM_FAULT_HWPOISON_LARGE | VM_FAULT_FALLBACK) 1502 1503 #define VM_FAULT_RESULT_TRACE \ 1504 { VM_FAULT_OOM, "OOM" }, \ 1505 { VM_FAULT_SIGBUS, "SIGBUS" }, \ 1506 { VM_FAULT_MAJOR, "MAJOR" }, \ 1507 { VM_FAULT_HWPOISON, "HWPOISON" }, \ 1508 { VM_FAULT_HWPOISON_LARGE, "HWPOISON_LARGE" }, \ 1509 { VM_FAULT_SIGSEGV, "SIGSEGV" }, \ 1510 { VM_FAULT_NOPAGE, "NOPAGE" }, \ 1511 { VM_FAULT_LOCKED, "LOCKED" }, \ 1512 { VM_FAULT_RETRY, "RETRY" }, \ 1513 { VM_FAULT_FALLBACK, "FALLBACK" }, \ 1514 { VM_FAULT_DONE_COW, "DONE_COW" }, \ 1515 { VM_FAULT_NEEDDSYNC, "NEEDDSYNC" }, \ 1516 { VM_FAULT_COMPLETED, "COMPLETED" } 1517 1518 struct vm_special_mapping { 1519 const char *name; /* The name, e.g. "[vdso]". */ 1520 1521 /* 1522 * If .fault is not provided, this points to a 1523 * NULL-terminated array of pages that back the special mapping. 1524 * 1525 * This must not be NULL unless .fault is provided. 1526 */ 1527 struct page **pages; 1528 1529 /* 1530 * If non-NULL, then this is called to resolve page faults 1531 * on the special mapping. If used, .pages is not checked. 1532 */ 1533 vm_fault_t (*fault)(const struct vm_special_mapping *sm, 1534 struct vm_area_struct *vma, 1535 struct vm_fault *vmf); 1536 1537 int (*mremap)(const struct vm_special_mapping *sm, 1538 struct vm_area_struct *new_vma); 1539 1540 void (*close)(const struct vm_special_mapping *sm, 1541 struct vm_area_struct *vma); 1542 }; 1543 1544 enum tlb_flush_reason { 1545 TLB_FLUSH_ON_TASK_SWITCH, 1546 TLB_REMOTE_SHOOTDOWN, 1547 TLB_LOCAL_SHOOTDOWN, 1548 TLB_LOCAL_MM_SHOOTDOWN, 1549 TLB_REMOTE_SEND_IPI, 1550 TLB_REMOTE_WRONG_CPU, 1551 NR_TLB_FLUSH_REASONS, 1552 }; 1553 1554 /** 1555 * enum fault_flag - Fault flag definitions. 1556 * @FAULT_FLAG_WRITE: Fault was a write fault. 1557 * @FAULT_FLAG_MKWRITE: Fault was mkwrite of existing PTE. 1558 * @FAULT_FLAG_ALLOW_RETRY: Allow to retry the fault if blocked. 1559 * @FAULT_FLAG_RETRY_NOWAIT: Don't drop mmap_lock and wait when retrying. 1560 * @FAULT_FLAG_KILLABLE: The fault task is in SIGKILL killable region. 1561 * @FAULT_FLAG_TRIED: The fault has been tried once. 1562 * @FAULT_FLAG_USER: The fault originated in userspace. 1563 * @FAULT_FLAG_REMOTE: The fault is not for current task/mm. 1564 * @FAULT_FLAG_INSTRUCTION: The fault was during an instruction fetch. 1565 * @FAULT_FLAG_INTERRUPTIBLE: The fault can be interrupted by non-fatal signals. 1566 * @FAULT_FLAG_UNSHARE: The fault is an unsharing request to break COW in a 1567 * COW mapping, making sure that an exclusive anon page is 1568 * mapped after the fault. 1569 * @FAULT_FLAG_ORIG_PTE_VALID: whether the fault has vmf->orig_pte cached. 1570 * We should only access orig_pte if this flag set. 1571 * @FAULT_FLAG_VMA_LOCK: The fault is handled under VMA lock. 1572 * 1573 * About @FAULT_FLAG_ALLOW_RETRY and @FAULT_FLAG_TRIED: we can specify 1574 * whether we would allow page faults to retry by specifying these two 1575 * fault flags correctly. Currently there can be three legal combinations: 1576 * 1577 * (a) ALLOW_RETRY and !TRIED: this means the page fault allows retry, and 1578 * this is the first try 1579 * 1580 * (b) ALLOW_RETRY and TRIED: this means the page fault allows retry, and 1581 * we've already tried at least once 1582 * 1583 * (c) !ALLOW_RETRY and !TRIED: this means the page fault does not allow retry 1584 * 1585 * The unlisted combination (!ALLOW_RETRY && TRIED) is illegal and should never 1586 * be used. Note that page faults can be allowed to retry for multiple times, 1587 * in which case we'll have an initial fault with flags (a) then later on 1588 * continuous faults with flags (b). We should always try to detect pending 1589 * signals before a retry to make sure the continuous page faults can still be 1590 * interrupted if necessary. 1591 * 1592 * The combination FAULT_FLAG_WRITE|FAULT_FLAG_UNSHARE is illegal. 1593 * FAULT_FLAG_UNSHARE is ignored and treated like an ordinary read fault when 1594 * applied to mappings that are not COW mappings. 1595 */ 1596 enum fault_flag { 1597 FAULT_FLAG_WRITE = 1 << 0, 1598 FAULT_FLAG_MKWRITE = 1 << 1, 1599 FAULT_FLAG_ALLOW_RETRY = 1 << 2, 1600 FAULT_FLAG_RETRY_NOWAIT = 1 << 3, 1601 FAULT_FLAG_KILLABLE = 1 << 4, 1602 FAULT_FLAG_TRIED = 1 << 5, 1603 FAULT_FLAG_USER = 1 << 6, 1604 FAULT_FLAG_REMOTE = 1 << 7, 1605 FAULT_FLAG_INSTRUCTION = 1 << 8, 1606 FAULT_FLAG_INTERRUPTIBLE = 1 << 9, 1607 FAULT_FLAG_UNSHARE = 1 << 10, 1608 FAULT_FLAG_ORIG_PTE_VALID = 1 << 11, 1609 FAULT_FLAG_VMA_LOCK = 1 << 12, 1610 }; 1611 1612 typedef unsigned int __bitwise zap_flags_t; 1613 1614 /* Flags for clear_young_dirty_ptes(). */ 1615 typedef int __bitwise cydp_t; 1616 1617 /* Clear the access bit */ 1618 #define CYDP_CLEAR_YOUNG ((__force cydp_t)BIT(0)) 1619 1620 /* Clear the dirty bit */ 1621 #define CYDP_CLEAR_DIRTY ((__force cydp_t)BIT(1)) 1622 1623 /* 1624 * FOLL_PIN and FOLL_LONGTERM may be used in various combinations with each 1625 * other. Here is what they mean, and how to use them: 1626 * 1627 * 1628 * FIXME: For pages which are part of a filesystem, mappings are subject to the 1629 * lifetime enforced by the filesystem and we need guarantees that longterm 1630 * users like RDMA and V4L2 only establish mappings which coordinate usage with 1631 * the filesystem. Ideas for this coordination include revoking the longterm 1632 * pin, delaying writeback, bounce buffer page writeback, etc. As FS DAX was 1633 * added after the problem with filesystems was found FS DAX VMAs are 1634 * specifically failed. Filesystem pages are still subject to bugs and use of 1635 * FOLL_LONGTERM should be avoided on those pages. 1636 * 1637 * In the CMA case: long term pins in a CMA region would unnecessarily fragment 1638 * that region. And so, CMA attempts to migrate the page before pinning, when 1639 * FOLL_LONGTERM is specified. 1640 * 1641 * FOLL_PIN indicates that a special kind of tracking (not just page->_refcount, 1642 * but an additional pin counting system) will be invoked. This is intended for 1643 * anything that gets a page reference and then touches page data (for example, 1644 * Direct IO). This lets the filesystem know that some non-file-system entity is 1645 * potentially changing the pages' data. In contrast to FOLL_GET (whose pages 1646 * are released via put_page()), FOLL_PIN pages must be released, ultimately, by 1647 * a call to unpin_user_page(). 1648 * 1649 * FOLL_PIN is similar to FOLL_GET: both of these pin pages. They use different 1650 * and separate refcounting mechanisms, however, and that means that each has 1651 * its own acquire and release mechanisms: 1652 * 1653 * FOLL_GET: get_user_pages*() to acquire, and put_page() to release. 1654 * 1655 * FOLL_PIN: pin_user_pages*() to acquire, and unpin_user_pages to release. 1656 * 1657 * FOLL_PIN and FOLL_GET are mutually exclusive for a given function call. 1658 * (The underlying pages may experience both FOLL_GET-based and FOLL_PIN-based 1659 * calls applied to them, and that's perfectly OK. This is a constraint on the 1660 * callers, not on the pages.) 1661 * 1662 * FOLL_PIN should be set internally by the pin_user_pages*() APIs, never 1663 * directly by the caller. That's in order to help avoid mismatches when 1664 * releasing pages: get_user_pages*() pages must be released via put_page(), 1665 * while pin_user_pages*() pages must be released via unpin_user_page(). 1666 * 1667 * Please see Documentation/core-api/pin_user_pages.rst for more information. 1668 */ 1669 1670 enum { 1671 /* check pte is writable */ 1672 FOLL_WRITE = 1 << 0, 1673 /* do get_page on page */ 1674 FOLL_GET = 1 << 1, 1675 /* give error on hole if it would be zero */ 1676 FOLL_DUMP = 1 << 2, 1677 /* get_user_pages read/write w/o permission */ 1678 FOLL_FORCE = 1 << 3, 1679 /* 1680 * if a disk transfer is needed, start the IO and return without waiting 1681 * upon it 1682 */ 1683 FOLL_NOWAIT = 1 << 4, 1684 /* do not fault in pages */ 1685 FOLL_NOFAULT = 1 << 5, 1686 /* check page is hwpoisoned */ 1687 FOLL_HWPOISON = 1 << 6, 1688 /* don't do file mappings */ 1689 FOLL_ANON = 1 << 7, 1690 /* 1691 * FOLL_LONGTERM indicates that the page will be held for an indefinite 1692 * time period _often_ under userspace control. This is in contrast to 1693 * iov_iter_get_pages(), whose usages are transient. 1694 */ 1695 FOLL_LONGTERM = 1 << 8, 1696 /* split huge pmd before returning */ 1697 FOLL_SPLIT_PMD = 1 << 9, 1698 /* allow returning PCI P2PDMA pages */ 1699 FOLL_PCI_P2PDMA = 1 << 10, 1700 /* allow interrupts from generic signals */ 1701 FOLL_INTERRUPTIBLE = 1 << 11, 1702 /* 1703 * Always honor (trigger) NUMA hinting faults. 1704 * 1705 * FOLL_WRITE implicitly honors NUMA hinting faults because a 1706 * PROT_NONE-mapped page is not writable (exceptions with FOLL_FORCE 1707 * apply). get_user_pages_fast_only() always implicitly honors NUMA 1708 * hinting faults. 1709 */ 1710 FOLL_HONOR_NUMA_FAULT = 1 << 12, 1711 1712 /* See also internal only FOLL flags in mm/internal.h */ 1713 }; 1714 1715 /* mm flags */ 1716 1717 /* 1718 * The first two bits represent core dump modes for set-user-ID, 1719 * the modes are SUID_DUMP_* defined in linux/sched/coredump.h 1720 */ 1721 #define MMF_DUMPABLE_BITS 2 1722 #define MMF_DUMPABLE_MASK ((1 << MMF_DUMPABLE_BITS) - 1) 1723 /* coredump filter bits */ 1724 #define MMF_DUMP_ANON_PRIVATE 2 1725 #define MMF_DUMP_ANON_SHARED 3 1726 #define MMF_DUMP_MAPPED_PRIVATE 4 1727 #define MMF_DUMP_MAPPED_SHARED 5 1728 #define MMF_DUMP_ELF_HEADERS 6 1729 #define MMF_DUMP_HUGETLB_PRIVATE 7 1730 #define MMF_DUMP_HUGETLB_SHARED 8 1731 #define MMF_DUMP_DAX_PRIVATE 9 1732 #define MMF_DUMP_DAX_SHARED 10 1733 1734 #define MMF_DUMP_FILTER_SHIFT MMF_DUMPABLE_BITS 1735 #define MMF_DUMP_FILTER_BITS 9 1736 #define MMF_DUMP_FILTER_MASK \ 1737 (((1 << MMF_DUMP_FILTER_BITS) - 1) << MMF_DUMP_FILTER_SHIFT) 1738 #define MMF_DUMP_FILTER_DEFAULT \ 1739 ((1 << MMF_DUMP_ANON_PRIVATE) | (1 << MMF_DUMP_ANON_SHARED) |\ 1740 (1 << MMF_DUMP_HUGETLB_PRIVATE) | MMF_DUMP_MASK_DEFAULT_ELF) 1741 1742 #ifdef CONFIG_CORE_DUMP_DEFAULT_ELF_HEADERS 1743 # define MMF_DUMP_MASK_DEFAULT_ELF (1 << MMF_DUMP_ELF_HEADERS) 1744 #else 1745 # define MMF_DUMP_MASK_DEFAULT_ELF 0 1746 #endif 1747 /* leave room for more dump flags */ 1748 #define MMF_VM_MERGEABLE 16 /* KSM may merge identical pages */ 1749 #define MMF_VM_HUGEPAGE 17 /* set when mm is available for khugepaged */ 1750 1751 /* 1752 * This one-shot flag is dropped due to necessity of changing exe once again 1753 * on NFS restore 1754 */ 1755 //#define MMF_EXE_FILE_CHANGED 18 /* see prctl_set_mm_exe_file() */ 1756 1757 #define MMF_HAS_UPROBES 19 /* has uprobes */ 1758 #define MMF_RECALC_UPROBES 20 /* MMF_HAS_UPROBES can be wrong */ 1759 #define MMF_OOM_SKIP 21 /* mm is of no interest for the OOM killer */ 1760 #define MMF_UNSTABLE 22 /* mm is unstable for copy_from_user */ 1761 #define MMF_HUGE_ZERO_PAGE 23 /* mm has ever used the global huge zero page */ 1762 #define MMF_DISABLE_THP 24 /* disable THP for all VMAs */ 1763 #define MMF_DISABLE_THP_MASK (1 << MMF_DISABLE_THP) 1764 #define MMF_OOM_REAP_QUEUED 25 /* mm was queued for oom_reaper */ 1765 #define MMF_MULTIPROCESS 26 /* mm is shared between processes */ 1766 /* 1767 * MMF_HAS_PINNED: Whether this mm has pinned any pages. This can be either 1768 * replaced in the future by mm.pinned_vm when it becomes stable, or grow into 1769 * a counter on its own. We're aggresive on this bit for now: even if the 1770 * pinned pages were unpinned later on, we'll still keep this bit set for the 1771 * lifecycle of this mm, just for simplicity. 1772 */ 1773 #define MMF_HAS_PINNED 27 /* FOLL_PIN has run, never cleared */ 1774 1775 #define MMF_HAS_MDWE 28 1776 #define MMF_HAS_MDWE_MASK (1 << MMF_HAS_MDWE) 1777 1778 1779 #define MMF_HAS_MDWE_NO_INHERIT 29 1780 1781 #define MMF_VM_MERGE_ANY 30 1782 #define MMF_VM_MERGE_ANY_MASK (1 << MMF_VM_MERGE_ANY) 1783 1784 #define MMF_TOPDOWN 31 /* mm searches top down by default */ 1785 #define MMF_TOPDOWN_MASK (1 << MMF_TOPDOWN) 1786 1787 #define MMF_INIT_MASK (MMF_DUMPABLE_MASK | MMF_DUMP_FILTER_MASK |\ 1788 MMF_DISABLE_THP_MASK | MMF_HAS_MDWE_MASK |\ 1789 MMF_VM_MERGE_ANY_MASK | MMF_TOPDOWN_MASK) 1790 1791 static inline unsigned long mmf_init_flags(unsigned long flags) 1792 { 1793 if (flags & (1UL << MMF_HAS_MDWE_NO_INHERIT)) 1794 flags &= ~((1UL << MMF_HAS_MDWE) | 1795 (1UL << MMF_HAS_MDWE_NO_INHERIT)); 1796 return flags & MMF_INIT_MASK; 1797 } 1798 1799 #endif /* _LINUX_MM_TYPES_H */ 1800