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