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 /** 291 * struct folio - Represents a contiguous set of bytes. 292 * @flags: Identical to the page flags. 293 * @lru: Least Recently Used list; tracks how recently this folio was used. 294 * @mlock_count: Number of times this folio has been pinned by mlock(). 295 * @mapping: The file this page belongs to, or refers to the anon_vma for 296 * anonymous memory. 297 * @index: Offset within the file, in units of pages. For anonymous memory, 298 * this is the index from the beginning of the mmap. 299 * @private: Filesystem per-folio data (see folio_attach_private()). 300 * @swap: Used for swp_entry_t if folio_test_swapcache(). 301 * @_mapcount: Do not access this member directly. Use folio_mapcount() to 302 * find out how many times this folio is mapped by userspace. 303 * @_refcount: Do not access this member directly. Use folio_ref_count() 304 * to find how many references there are to this folio. 305 * @memcg_data: Memory Control Group data. 306 * @pgmap: Metadata for ZONE_DEVICE mappings 307 * @virtual: Virtual address in the kernel direct map. 308 * @_last_cpupid: IDs of last CPU and last process that accessed the folio. 309 * @_entire_mapcount: Do not use directly, call folio_entire_mapcount(). 310 * @_large_mapcount: Do not use directly, call folio_mapcount(). 311 * @_nr_pages_mapped: Do not use outside of rmap and debug code. 312 * @_pincount: Do not use directly, call folio_maybe_dma_pinned(). 313 * @_folio_nr_pages: Do not use directly, call folio_nr_pages(). 314 * @_hugetlb_subpool: Do not use directly, use accessor in hugetlb.h. 315 * @_hugetlb_cgroup: Do not use directly, use accessor in hugetlb_cgroup.h. 316 * @_hugetlb_cgroup_rsvd: Do not use directly, use accessor in hugetlb_cgroup.h. 317 * @_hugetlb_hwpoison: Do not use directly, call raw_hwp_list_head(). 318 * @_deferred_list: Folios to be split under memory pressure. 319 * @_unused_slab_obj_exts: Placeholder to match obj_exts in struct slab. 320 * 321 * A folio is a physically, virtually and logically contiguous set 322 * of bytes. It is a power-of-two in size, and it is aligned to that 323 * same power-of-two. It is at least as large as %PAGE_SIZE. If it is 324 * in the page cache, it is at a file offset which is a multiple of that 325 * power-of-two. It may be mapped into userspace at an address which is 326 * at an arbitrary page offset, but its kernel virtual address is aligned 327 * to its size. 328 */ 329 struct folio { 330 /* private: don't document the anon union */ 331 union { 332 struct { 333 /* public: */ 334 unsigned long flags; 335 union { 336 struct list_head lru; 337 /* private: avoid cluttering the output */ 338 struct { 339 void *__filler; 340 /* public: */ 341 unsigned int mlock_count; 342 /* private: */ 343 }; 344 /* public: */ 345 struct dev_pagemap *pgmap; 346 }; 347 struct address_space *mapping; 348 pgoff_t index; 349 union { 350 void *private; 351 swp_entry_t swap; 352 }; 353 atomic_t _mapcount; 354 atomic_t _refcount; 355 #ifdef CONFIG_MEMCG 356 unsigned long memcg_data; 357 #elif defined(CONFIG_SLAB_OBJ_EXT) 358 unsigned long _unused_slab_obj_exts; 359 #endif 360 #if defined(WANT_PAGE_VIRTUAL) 361 void *virtual; 362 #endif 363 #ifdef LAST_CPUPID_NOT_IN_PAGE_FLAGS 364 int _last_cpupid; 365 #endif 366 /* private: the union with struct page is transitional */ 367 }; 368 struct page page; 369 }; 370 union { 371 struct { 372 unsigned long _flags_1; 373 unsigned long _head_1; 374 /* public: */ 375 atomic_t _large_mapcount; 376 atomic_t _entire_mapcount; 377 atomic_t _nr_pages_mapped; 378 atomic_t _pincount; 379 #ifdef CONFIG_64BIT 380 unsigned int _folio_nr_pages; 381 #endif 382 /* private: the union with struct page is transitional */ 383 }; 384 struct page __page_1; 385 }; 386 union { 387 struct { 388 unsigned long _flags_2; 389 unsigned long _head_2; 390 /* public: */ 391 void *_hugetlb_subpool; 392 void *_hugetlb_cgroup; 393 void *_hugetlb_cgroup_rsvd; 394 void *_hugetlb_hwpoison; 395 /* private: the union with struct page is transitional */ 396 }; 397 struct { 398 unsigned long _flags_2a; 399 unsigned long _head_2a; 400 /* public: */ 401 struct list_head _deferred_list; 402 /* private: the union with struct page is transitional */ 403 }; 404 struct page __page_2; 405 }; 406 }; 407 408 #define FOLIO_MATCH(pg, fl) \ 409 static_assert(offsetof(struct page, pg) == offsetof(struct folio, fl)) 410 FOLIO_MATCH(flags, flags); 411 FOLIO_MATCH(lru, lru); 412 FOLIO_MATCH(mapping, mapping); 413 FOLIO_MATCH(compound_head, lru); 414 FOLIO_MATCH(index, index); 415 FOLIO_MATCH(private, private); 416 FOLIO_MATCH(_mapcount, _mapcount); 417 FOLIO_MATCH(_refcount, _refcount); 418 #ifdef CONFIG_MEMCG 419 FOLIO_MATCH(memcg_data, memcg_data); 420 #endif 421 #if defined(WANT_PAGE_VIRTUAL) 422 FOLIO_MATCH(virtual, virtual); 423 #endif 424 #ifdef LAST_CPUPID_NOT_IN_PAGE_FLAGS 425 FOLIO_MATCH(_last_cpupid, _last_cpupid); 426 #endif 427 #undef FOLIO_MATCH 428 #define FOLIO_MATCH(pg, fl) \ 429 static_assert(offsetof(struct folio, fl) == \ 430 offsetof(struct page, pg) + sizeof(struct page)) 431 FOLIO_MATCH(flags, _flags_1); 432 FOLIO_MATCH(compound_head, _head_1); 433 #undef FOLIO_MATCH 434 #define FOLIO_MATCH(pg, fl) \ 435 static_assert(offsetof(struct folio, fl) == \ 436 offsetof(struct page, pg) + 2 * sizeof(struct page)) 437 FOLIO_MATCH(flags, _flags_2); 438 FOLIO_MATCH(compound_head, _head_2); 439 FOLIO_MATCH(flags, _flags_2a); 440 FOLIO_MATCH(compound_head, _head_2a); 441 #undef FOLIO_MATCH 442 443 /** 444 * struct ptdesc - Memory descriptor for page tables. 445 * @__page_flags: Same as page flags. Powerpc only. 446 * @pt_rcu_head: For freeing page table pages. 447 * @pt_list: List of used page tables. Used for s390 gmap shadow pages 448 * (which are not linked into the user page tables) and x86 449 * pgds. 450 * @_pt_pad_1: Padding that aliases with page's compound head. 451 * @pmd_huge_pte: Protected by ptdesc->ptl, used for THPs. 452 * @__page_mapping: Aliases with page->mapping. Unused for page tables. 453 * @pt_index: Used for s390 gmap. 454 * @pt_mm: Used for x86 pgds. 455 * @pt_frag_refcount: For fragmented page table tracking. Powerpc only. 456 * @pt_share_count: Used for HugeTLB PMD page table share count. 457 * @_pt_pad_2: Padding to ensure proper alignment. 458 * @ptl: Lock for the page table. 459 * @__page_type: Same as page->page_type. Unused for page tables. 460 * @__page_refcount: Same as page refcount. 461 * @pt_memcg_data: Memcg data. Tracked for page tables here. 462 * 463 * This struct overlays struct page for now. Do not modify without a good 464 * understanding of the issues. 465 */ 466 struct ptdesc { 467 unsigned long __page_flags; 468 469 union { 470 struct rcu_head pt_rcu_head; 471 struct list_head pt_list; 472 struct { 473 unsigned long _pt_pad_1; 474 pgtable_t pmd_huge_pte; 475 }; 476 }; 477 unsigned long __page_mapping; 478 479 union { 480 pgoff_t pt_index; 481 struct mm_struct *pt_mm; 482 atomic_t pt_frag_refcount; 483 #ifdef CONFIG_HUGETLB_PMD_PAGE_TABLE_SHARING 484 atomic_t pt_share_count; 485 #endif 486 }; 487 488 union { 489 unsigned long _pt_pad_2; 490 #if ALLOC_SPLIT_PTLOCKS 491 spinlock_t *ptl; 492 #else 493 spinlock_t ptl; 494 #endif 495 }; 496 unsigned int __page_type; 497 atomic_t __page_refcount; 498 #ifdef CONFIG_MEMCG 499 unsigned long pt_memcg_data; 500 #endif 501 }; 502 503 #define TABLE_MATCH(pg, pt) \ 504 static_assert(offsetof(struct page, pg) == offsetof(struct ptdesc, pt)) 505 TABLE_MATCH(flags, __page_flags); 506 TABLE_MATCH(compound_head, pt_list); 507 TABLE_MATCH(compound_head, _pt_pad_1); 508 TABLE_MATCH(mapping, __page_mapping); 509 TABLE_MATCH(index, pt_index); 510 TABLE_MATCH(rcu_head, pt_rcu_head); 511 TABLE_MATCH(page_type, __page_type); 512 TABLE_MATCH(_refcount, __page_refcount); 513 #ifdef CONFIG_MEMCG 514 TABLE_MATCH(memcg_data, pt_memcg_data); 515 #endif 516 #undef TABLE_MATCH 517 static_assert(sizeof(struct ptdesc) <= sizeof(struct page)); 518 519 #define ptdesc_page(pt) (_Generic((pt), \ 520 const struct ptdesc *: (const struct page *)(pt), \ 521 struct ptdesc *: (struct page *)(pt))) 522 523 #define ptdesc_folio(pt) (_Generic((pt), \ 524 const struct ptdesc *: (const struct folio *)(pt), \ 525 struct ptdesc *: (struct folio *)(pt))) 526 527 #define page_ptdesc(p) (_Generic((p), \ 528 const struct page *: (const struct ptdesc *)(p), \ 529 struct page *: (struct ptdesc *)(p))) 530 531 #ifdef CONFIG_HUGETLB_PMD_PAGE_TABLE_SHARING 532 static inline void ptdesc_pmd_pts_init(struct ptdesc *ptdesc) 533 { 534 atomic_set(&ptdesc->pt_share_count, 0); 535 } 536 537 static inline void ptdesc_pmd_pts_inc(struct ptdesc *ptdesc) 538 { 539 atomic_inc(&ptdesc->pt_share_count); 540 } 541 542 static inline void ptdesc_pmd_pts_dec(struct ptdesc *ptdesc) 543 { 544 atomic_dec(&ptdesc->pt_share_count); 545 } 546 547 static inline int ptdesc_pmd_pts_count(struct ptdesc *ptdesc) 548 { 549 return atomic_read(&ptdesc->pt_share_count); 550 } 551 #else 552 static inline void ptdesc_pmd_pts_init(struct ptdesc *ptdesc) 553 { 554 } 555 #endif 556 557 /* 558 * Used for sizing the vmemmap region on some architectures 559 */ 560 #define STRUCT_PAGE_MAX_SHIFT (order_base_2(sizeof(struct page))) 561 562 /* 563 * page_private can be used on tail pages. However, PagePrivate is only 564 * checked by the VM on the head page. So page_private on the tail pages 565 * should be used for data that's ancillary to the head page (eg attaching 566 * buffer heads to tail pages after attaching buffer heads to the head page) 567 */ 568 #define page_private(page) ((page)->private) 569 570 static inline void set_page_private(struct page *page, unsigned long private) 571 { 572 page->private = private; 573 } 574 575 static inline void *folio_get_private(struct folio *folio) 576 { 577 return folio->private; 578 } 579 580 typedef unsigned long vm_flags_t; 581 582 /* 583 * freeptr_t represents a SLUB freelist pointer, which might be encoded 584 * and not dereferenceable if CONFIG_SLAB_FREELIST_HARDENED is enabled. 585 */ 586 typedef struct { unsigned long v; } freeptr_t; 587 588 /* 589 * A region containing a mapping of a non-memory backed file under NOMMU 590 * conditions. These are held in a global tree and are pinned by the VMAs that 591 * map parts of them. 592 */ 593 struct vm_region { 594 struct rb_node vm_rb; /* link in global region tree */ 595 vm_flags_t vm_flags; /* VMA vm_flags */ 596 unsigned long vm_start; /* start address of region */ 597 unsigned long vm_end; /* region initialised to here */ 598 unsigned long vm_top; /* region allocated to here */ 599 unsigned long vm_pgoff; /* the offset in vm_file corresponding to vm_start */ 600 struct file *vm_file; /* the backing file or NULL */ 601 602 int vm_usage; /* region usage count (access under nommu_region_sem) */ 603 bool vm_icache_flushed : 1; /* true if the icache has been flushed for 604 * this region */ 605 }; 606 607 #ifdef CONFIG_USERFAULTFD 608 #define NULL_VM_UFFD_CTX ((struct vm_userfaultfd_ctx) { NULL, }) 609 struct vm_userfaultfd_ctx { 610 struct userfaultfd_ctx *ctx; 611 }; 612 #else /* CONFIG_USERFAULTFD */ 613 #define NULL_VM_UFFD_CTX ((struct vm_userfaultfd_ctx) {}) 614 struct vm_userfaultfd_ctx {}; 615 #endif /* CONFIG_USERFAULTFD */ 616 617 struct anon_vma_name { 618 struct kref kref; 619 /* The name needs to be at the end because it is dynamically sized. */ 620 char name[]; 621 }; 622 623 #ifdef CONFIG_ANON_VMA_NAME 624 /* 625 * mmap_lock should be read-locked when calling anon_vma_name(). Caller should 626 * either keep holding the lock while using the returned pointer or it should 627 * raise anon_vma_name refcount before releasing the lock. 628 */ 629 struct anon_vma_name *anon_vma_name(struct vm_area_struct *vma); 630 struct anon_vma_name *anon_vma_name_alloc(const char *name); 631 void anon_vma_name_free(struct kref *kref); 632 #else /* CONFIG_ANON_VMA_NAME */ 633 static inline struct anon_vma_name *anon_vma_name(struct vm_area_struct *vma) 634 { 635 return NULL; 636 } 637 638 static inline struct anon_vma_name *anon_vma_name_alloc(const char *name) 639 { 640 return NULL; 641 } 642 #endif 643 644 #define VMA_LOCK_OFFSET 0x40000000 645 #define VMA_REF_LIMIT (VMA_LOCK_OFFSET - 1) 646 647 struct vma_numab_state { 648 /* 649 * Initialised as time in 'jiffies' after which VMA 650 * should be scanned. Delays first scan of new VMA by at 651 * least sysctl_numa_balancing_scan_delay: 652 */ 653 unsigned long next_scan; 654 655 /* 656 * Time in jiffies when pids_active[] is reset to 657 * detect phase change behaviour: 658 */ 659 unsigned long pids_active_reset; 660 661 /* 662 * Approximate tracking of PIDs that trapped a NUMA hinting 663 * fault. May produce false positives due to hash collisions. 664 * 665 * [0] Previous PID tracking 666 * [1] Current PID tracking 667 * 668 * Window moves after next_pid_reset has expired approximately 669 * every VMA_PID_RESET_PERIOD jiffies: 670 */ 671 unsigned long pids_active[2]; 672 673 /* MM scan sequence ID when scan first started after VMA creation */ 674 int start_scan_seq; 675 676 /* 677 * MM scan sequence ID when the VMA was last completely scanned. 678 * A VMA is not eligible for scanning if prev_scan_seq == numa_scan_seq 679 */ 680 int prev_scan_seq; 681 }; 682 683 /* 684 * This struct describes a virtual memory area. There is one of these 685 * per VM-area/task. A VM area is any part of the process virtual memory 686 * space that has a special rule for the page-fault handlers (ie a shared 687 * library, the executable area etc). 688 * 689 * Only explicitly marked struct members may be accessed by RCU readers before 690 * getting a stable reference. 691 * 692 * WARNING: when adding new members, please update vm_area_init_from() to copy 693 * them during vm_area_struct content duplication. 694 */ 695 struct vm_area_struct { 696 /* The first cache line has the info for VMA tree walking. */ 697 698 union { 699 struct { 700 /* VMA covers [vm_start; vm_end) addresses within mm */ 701 unsigned long vm_start; 702 unsigned long vm_end; 703 }; 704 freeptr_t vm_freeptr; /* Pointer used by SLAB_TYPESAFE_BY_RCU */ 705 }; 706 707 /* 708 * The address space we belong to. 709 * Unstable RCU readers are allowed to read this. 710 */ 711 struct mm_struct *vm_mm; 712 pgprot_t vm_page_prot; /* Access permissions of this VMA. */ 713 714 /* 715 * Flags, see mm.h. 716 * To modify use vm_flags_{init|reset|set|clear|mod} functions. 717 */ 718 union { 719 const vm_flags_t vm_flags; 720 vm_flags_t __private __vm_flags; 721 }; 722 723 #ifdef CONFIG_PER_VMA_LOCK 724 /* 725 * Can only be written (using WRITE_ONCE()) while holding both: 726 * - mmap_lock (in write mode) 727 * - vm_refcnt bit at VMA_LOCK_OFFSET is set 728 * Can be read reliably while holding one of: 729 * - mmap_lock (in read or write mode) 730 * - vm_refcnt bit at VMA_LOCK_OFFSET is set or vm_refcnt > 1 731 * Can be read unreliably (using READ_ONCE()) for pessimistic bailout 732 * while holding nothing (except RCU to keep the VMA struct allocated). 733 * 734 * This sequence counter is explicitly allowed to overflow; sequence 735 * counter reuse can only lead to occasional unnecessary use of the 736 * slowpath. 737 */ 738 unsigned int vm_lock_seq; 739 #endif 740 /* 741 * A file's MAP_PRIVATE vma can be in both i_mmap tree and anon_vma 742 * list, after a COW of one of the file pages. A MAP_SHARED vma 743 * can only be in the i_mmap tree. An anonymous MAP_PRIVATE, stack 744 * or brk vma (with NULL file) can only be in an anon_vma list. 745 */ 746 struct list_head anon_vma_chain; /* Serialized by mmap_lock & 747 * page_table_lock */ 748 struct anon_vma *anon_vma; /* Serialized by page_table_lock */ 749 750 /* Function pointers to deal with this struct. */ 751 const struct vm_operations_struct *vm_ops; 752 753 /* Information about our backing store: */ 754 unsigned long vm_pgoff; /* Offset (within vm_file) in PAGE_SIZE 755 units */ 756 struct file * vm_file; /* File we map to (can be NULL). */ 757 void * vm_private_data; /* was vm_pte (shared mem) */ 758 759 #ifdef CONFIG_SWAP 760 atomic_long_t swap_readahead_info; 761 #endif 762 #ifndef CONFIG_MMU 763 struct vm_region *vm_region; /* NOMMU mapping region */ 764 #endif 765 #ifdef CONFIG_NUMA 766 struct mempolicy *vm_policy; /* NUMA policy for the VMA */ 767 #endif 768 #ifdef CONFIG_NUMA_BALANCING 769 struct vma_numab_state *numab_state; /* NUMA Balancing state */ 770 #endif 771 #ifdef CONFIG_PER_VMA_LOCK 772 /* Unstable RCU readers are allowed to read this. */ 773 refcount_t vm_refcnt ____cacheline_aligned_in_smp; 774 #ifdef CONFIG_DEBUG_LOCK_ALLOC 775 struct lockdep_map vmlock_dep_map; 776 #endif 777 #endif 778 /* 779 * For areas with an address space and backing store, 780 * linkage into the address_space->i_mmap interval tree. 781 * 782 */ 783 struct { 784 struct rb_node rb; 785 unsigned long rb_subtree_last; 786 } shared; 787 #ifdef CONFIG_ANON_VMA_NAME 788 /* 789 * For private and shared anonymous mappings, a pointer to a null 790 * terminated string containing the name given to the vma, or NULL if 791 * unnamed. Serialized by mmap_lock. Use anon_vma_name to access. 792 */ 793 struct anon_vma_name *anon_name; 794 #endif 795 struct vm_userfaultfd_ctx vm_userfaultfd_ctx; 796 } __randomize_layout; 797 798 #ifdef CONFIG_NUMA 799 #define vma_policy(vma) ((vma)->vm_policy) 800 #else 801 #define vma_policy(vma) NULL 802 #endif 803 804 #ifdef CONFIG_SCHED_MM_CID 805 struct mm_cid { 806 u64 time; 807 int cid; 808 int recent_cid; 809 }; 810 #endif 811 812 struct kioctx_table; 813 struct iommu_mm_data; 814 struct mm_struct { 815 struct { 816 /* 817 * Fields which are often written to are placed in a separate 818 * cache line. 819 */ 820 struct { 821 /** 822 * @mm_count: The number of references to &struct 823 * mm_struct (@mm_users count as 1). 824 * 825 * Use mmgrab()/mmdrop() to modify. When this drops to 826 * 0, the &struct mm_struct is freed. 827 */ 828 atomic_t mm_count; 829 } ____cacheline_aligned_in_smp; 830 831 struct maple_tree mm_mt; 832 833 unsigned long mmap_base; /* base of mmap area */ 834 unsigned long mmap_legacy_base; /* base of mmap area in bottom-up allocations */ 835 #ifdef CONFIG_HAVE_ARCH_COMPAT_MMAP_BASES 836 /* Base addresses for compatible mmap() */ 837 unsigned long mmap_compat_base; 838 unsigned long mmap_compat_legacy_base; 839 #endif 840 unsigned long task_size; /* size of task vm space */ 841 pgd_t * pgd; 842 843 #ifdef CONFIG_MEMBARRIER 844 /** 845 * @membarrier_state: Flags controlling membarrier behavior. 846 * 847 * This field is close to @pgd to hopefully fit in the same 848 * cache-line, which needs to be touched by switch_mm(). 849 */ 850 atomic_t membarrier_state; 851 #endif 852 853 /** 854 * @mm_users: The number of users including userspace. 855 * 856 * Use mmget()/mmget_not_zero()/mmput() to modify. When this 857 * drops to 0 (i.e. when the task exits and there are no other 858 * temporary reference holders), we also release a reference on 859 * @mm_count (which may then free the &struct mm_struct if 860 * @mm_count also drops to 0). 861 */ 862 atomic_t mm_users; 863 864 #ifdef CONFIG_SCHED_MM_CID 865 /** 866 * @pcpu_cid: Per-cpu current cid. 867 * 868 * Keep track of the currently allocated mm_cid for each cpu. 869 * The per-cpu mm_cid values are serialized by their respective 870 * runqueue locks. 871 */ 872 struct mm_cid __percpu *pcpu_cid; 873 /* 874 * @mm_cid_next_scan: Next mm_cid scan (in jiffies). 875 * 876 * When the next mm_cid scan is due (in jiffies). 877 */ 878 unsigned long mm_cid_next_scan; 879 /** 880 * @nr_cpus_allowed: Number of CPUs allowed for mm. 881 * 882 * Number of CPUs allowed in the union of all mm's 883 * threads allowed CPUs. 884 */ 885 unsigned int nr_cpus_allowed; 886 /** 887 * @max_nr_cid: Maximum number of allowed concurrency 888 * IDs allocated. 889 * 890 * Track the highest number of allowed concurrency IDs 891 * allocated for the mm. 892 */ 893 atomic_t max_nr_cid; 894 /** 895 * @cpus_allowed_lock: Lock protecting mm cpus_allowed. 896 * 897 * Provide mutual exclusion for mm cpus_allowed and 898 * mm nr_cpus_allowed updates. 899 */ 900 raw_spinlock_t cpus_allowed_lock; 901 #endif 902 #ifdef CONFIG_MMU 903 atomic_long_t pgtables_bytes; /* size of all page tables */ 904 #endif 905 int map_count; /* number of VMAs */ 906 907 spinlock_t page_table_lock; /* Protects page tables and some 908 * counters 909 */ 910 /* 911 * With some kernel config, the current mmap_lock's offset 912 * inside 'mm_struct' is at 0x120, which is very optimal, as 913 * its two hot fields 'count' and 'owner' sit in 2 different 914 * cachelines, and when mmap_lock is highly contended, both 915 * of the 2 fields will be accessed frequently, current layout 916 * will help to reduce cache bouncing. 917 * 918 * So please be careful with adding new fields before 919 * mmap_lock, which can easily push the 2 fields into one 920 * cacheline. 921 */ 922 struct rw_semaphore mmap_lock; 923 924 struct list_head mmlist; /* List of maybe swapped mm's. These 925 * are globally strung together off 926 * init_mm.mmlist, and are protected 927 * by mmlist_lock 928 */ 929 #ifdef CONFIG_PER_VMA_LOCK 930 struct rcuwait vma_writer_wait; 931 /* 932 * This field has lock-like semantics, meaning it is sometimes 933 * accessed with ACQUIRE/RELEASE semantics. 934 * Roughly speaking, incrementing the sequence number is 935 * equivalent to releasing locks on VMAs; reading the sequence 936 * number can be part of taking a read lock on a VMA. 937 * Incremented every time mmap_lock is write-locked/unlocked. 938 * Initialized to 0, therefore odd values indicate mmap_lock 939 * is write-locked and even values that it's released. 940 * 941 * Can be modified under write mmap_lock using RELEASE 942 * semantics. 943 * Can be read with no other protection when holding write 944 * mmap_lock. 945 * Can be read with ACQUIRE semantics if not holding write 946 * mmap_lock. 947 */ 948 seqcount_t mm_lock_seq; 949 #endif 950 951 952 unsigned long hiwater_rss; /* High-watermark of RSS usage */ 953 unsigned long hiwater_vm; /* High-water virtual memory usage */ 954 955 unsigned long total_vm; /* Total pages mapped */ 956 unsigned long locked_vm; /* Pages that have PG_mlocked set */ 957 atomic64_t pinned_vm; /* Refcount permanently increased */ 958 unsigned long data_vm; /* VM_WRITE & ~VM_SHARED & ~VM_STACK */ 959 unsigned long exec_vm; /* VM_EXEC & ~VM_WRITE & ~VM_STACK */ 960 unsigned long stack_vm; /* VM_STACK */ 961 unsigned long def_flags; 962 963 /** 964 * @write_protect_seq: Locked when any thread is write 965 * protecting pages mapped by this mm to enforce a later COW, 966 * for instance during page table copying for fork(). 967 */ 968 seqcount_t write_protect_seq; 969 970 spinlock_t arg_lock; /* protect the below fields */ 971 972 unsigned long start_code, end_code, start_data, end_data; 973 unsigned long start_brk, brk, start_stack; 974 unsigned long arg_start, arg_end, env_start, env_end; 975 976 unsigned long saved_auxv[AT_VECTOR_SIZE]; /* for /proc/PID/auxv */ 977 978 struct percpu_counter rss_stat[NR_MM_COUNTERS]; 979 980 struct linux_binfmt *binfmt; 981 982 /* Architecture-specific MM context */ 983 mm_context_t context; 984 985 unsigned long flags; /* Must use atomic bitops to access */ 986 987 #ifdef CONFIG_AIO 988 spinlock_t ioctx_lock; 989 struct kioctx_table __rcu *ioctx_table; 990 #endif 991 #ifdef CONFIG_MEMCG 992 /* 993 * "owner" points to a task that is regarded as the canonical 994 * user/owner of this mm. All of the following must be true in 995 * order for it to be changed: 996 * 997 * current == mm->owner 998 * current->mm != mm 999 * new_owner->mm == mm 1000 * new_owner->alloc_lock is held 1001 */ 1002 struct task_struct __rcu *owner; 1003 #endif 1004 struct user_namespace *user_ns; 1005 1006 /* store ref to file /proc/<pid>/exe symlink points to */ 1007 struct file __rcu *exe_file; 1008 #ifdef CONFIG_MMU_NOTIFIER 1009 struct mmu_notifier_subscriptions *notifier_subscriptions; 1010 #endif 1011 #if defined(CONFIG_TRANSPARENT_HUGEPAGE) && !defined(CONFIG_SPLIT_PMD_PTLOCKS) 1012 pgtable_t pmd_huge_pte; /* protected by page_table_lock */ 1013 #endif 1014 #ifdef CONFIG_NUMA_BALANCING 1015 /* 1016 * numa_next_scan is the next time that PTEs will be remapped 1017 * PROT_NONE to trigger NUMA hinting faults; such faults gather 1018 * statistics and migrate pages to new nodes if necessary. 1019 */ 1020 unsigned long numa_next_scan; 1021 1022 /* Restart point for scanning and remapping PTEs. */ 1023 unsigned long numa_scan_offset; 1024 1025 /* numa_scan_seq prevents two threads remapping PTEs. */ 1026 int numa_scan_seq; 1027 #endif 1028 /* 1029 * An operation with batched TLB flushing is going on. Anything 1030 * that can move process memory needs to flush the TLB when 1031 * moving a PROT_NONE mapped page. 1032 */ 1033 atomic_t tlb_flush_pending; 1034 #ifdef CONFIG_ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH 1035 /* See flush_tlb_batched_pending() */ 1036 atomic_t tlb_flush_batched; 1037 #endif 1038 struct uprobes_state uprobes_state; 1039 #ifdef CONFIG_PREEMPT_RT 1040 struct rcu_head delayed_drop; 1041 #endif 1042 #ifdef CONFIG_HUGETLB_PAGE 1043 atomic_long_t hugetlb_usage; 1044 #endif 1045 struct work_struct async_put_work; 1046 1047 #ifdef CONFIG_IOMMU_MM_DATA 1048 struct iommu_mm_data *iommu_mm; 1049 #endif 1050 #ifdef CONFIG_KSM 1051 /* 1052 * Represent how many pages of this process are involved in KSM 1053 * merging (not including ksm_zero_pages). 1054 */ 1055 unsigned long ksm_merging_pages; 1056 /* 1057 * Represent how many pages are checked for ksm merging 1058 * including merged and not merged. 1059 */ 1060 unsigned long ksm_rmap_items; 1061 /* 1062 * Represent how many empty pages are merged with kernel zero 1063 * pages when enabling KSM use_zero_pages. 1064 */ 1065 atomic_long_t ksm_zero_pages; 1066 #endif /* CONFIG_KSM */ 1067 #ifdef CONFIG_LRU_GEN_WALKS_MMU 1068 struct { 1069 /* this mm_struct is on lru_gen_mm_list */ 1070 struct list_head list; 1071 /* 1072 * Set when switching to this mm_struct, as a hint of 1073 * whether it has been used since the last time per-node 1074 * page table walkers cleared the corresponding bits. 1075 */ 1076 unsigned long bitmap; 1077 #ifdef CONFIG_MEMCG 1078 /* points to the memcg of "owner" above */ 1079 struct mem_cgroup *memcg; 1080 #endif 1081 } lru_gen; 1082 #endif /* CONFIG_LRU_GEN_WALKS_MMU */ 1083 } __randomize_layout; 1084 1085 /* 1086 * The mm_cpumask needs to be at the end of mm_struct, because it 1087 * is dynamically sized based on nr_cpu_ids. 1088 */ 1089 unsigned long cpu_bitmap[]; 1090 }; 1091 1092 #define MM_MT_FLAGS (MT_FLAGS_ALLOC_RANGE | MT_FLAGS_LOCK_EXTERN | \ 1093 MT_FLAGS_USE_RCU) 1094 extern struct mm_struct init_mm; 1095 1096 /* Pointer magic because the dynamic array size confuses some compilers. */ 1097 static inline void mm_init_cpumask(struct mm_struct *mm) 1098 { 1099 unsigned long cpu_bitmap = (unsigned long)mm; 1100 1101 cpu_bitmap += offsetof(struct mm_struct, cpu_bitmap); 1102 cpumask_clear((struct cpumask *)cpu_bitmap); 1103 } 1104 1105 /* Future-safe accessor for struct mm_struct's cpu_vm_mask. */ 1106 static inline cpumask_t *mm_cpumask(struct mm_struct *mm) 1107 { 1108 return (struct cpumask *)&mm->cpu_bitmap; 1109 } 1110 1111 #ifdef CONFIG_LRU_GEN 1112 1113 struct lru_gen_mm_list { 1114 /* mm_struct list for page table walkers */ 1115 struct list_head fifo; 1116 /* protects the list above */ 1117 spinlock_t lock; 1118 }; 1119 1120 #endif /* CONFIG_LRU_GEN */ 1121 1122 #ifdef CONFIG_LRU_GEN_WALKS_MMU 1123 1124 void lru_gen_add_mm(struct mm_struct *mm); 1125 void lru_gen_del_mm(struct mm_struct *mm); 1126 void lru_gen_migrate_mm(struct mm_struct *mm); 1127 1128 static inline void lru_gen_init_mm(struct mm_struct *mm) 1129 { 1130 INIT_LIST_HEAD(&mm->lru_gen.list); 1131 mm->lru_gen.bitmap = 0; 1132 #ifdef CONFIG_MEMCG 1133 mm->lru_gen.memcg = NULL; 1134 #endif 1135 } 1136 1137 static inline void lru_gen_use_mm(struct mm_struct *mm) 1138 { 1139 /* 1140 * When the bitmap is set, page reclaim knows this mm_struct has been 1141 * used since the last time it cleared the bitmap. So it might be worth 1142 * walking the page tables of this mm_struct to clear the accessed bit. 1143 */ 1144 WRITE_ONCE(mm->lru_gen.bitmap, -1); 1145 } 1146 1147 #else /* !CONFIG_LRU_GEN_WALKS_MMU */ 1148 1149 static inline void lru_gen_add_mm(struct mm_struct *mm) 1150 { 1151 } 1152 1153 static inline void lru_gen_del_mm(struct mm_struct *mm) 1154 { 1155 } 1156 1157 static inline void lru_gen_migrate_mm(struct mm_struct *mm) 1158 { 1159 } 1160 1161 static inline void lru_gen_init_mm(struct mm_struct *mm) 1162 { 1163 } 1164 1165 static inline void lru_gen_use_mm(struct mm_struct *mm) 1166 { 1167 } 1168 1169 #endif /* CONFIG_LRU_GEN_WALKS_MMU */ 1170 1171 struct vma_iterator { 1172 struct ma_state mas; 1173 }; 1174 1175 #define VMA_ITERATOR(name, __mm, __addr) \ 1176 struct vma_iterator name = { \ 1177 .mas = { \ 1178 .tree = &(__mm)->mm_mt, \ 1179 .index = __addr, \ 1180 .node = NULL, \ 1181 .status = ma_start, \ 1182 }, \ 1183 } 1184 1185 static inline void vma_iter_init(struct vma_iterator *vmi, 1186 struct mm_struct *mm, unsigned long addr) 1187 { 1188 mas_init(&vmi->mas, &mm->mm_mt, addr); 1189 } 1190 1191 #ifdef CONFIG_SCHED_MM_CID 1192 1193 enum mm_cid_state { 1194 MM_CID_UNSET = -1U, /* Unset state has lazy_put flag set. */ 1195 MM_CID_LAZY_PUT = (1U << 31), 1196 }; 1197 1198 static inline bool mm_cid_is_unset(int cid) 1199 { 1200 return cid == MM_CID_UNSET; 1201 } 1202 1203 static inline bool mm_cid_is_lazy_put(int cid) 1204 { 1205 return !mm_cid_is_unset(cid) && (cid & MM_CID_LAZY_PUT); 1206 } 1207 1208 static inline bool mm_cid_is_valid(int cid) 1209 { 1210 return !(cid & MM_CID_LAZY_PUT); 1211 } 1212 1213 static inline int mm_cid_set_lazy_put(int cid) 1214 { 1215 return cid | MM_CID_LAZY_PUT; 1216 } 1217 1218 static inline int mm_cid_clear_lazy_put(int cid) 1219 { 1220 return cid & ~MM_CID_LAZY_PUT; 1221 } 1222 1223 /* 1224 * mm_cpus_allowed: Union of all mm's threads allowed CPUs. 1225 */ 1226 static inline cpumask_t *mm_cpus_allowed(struct mm_struct *mm) 1227 { 1228 unsigned long bitmap = (unsigned long)mm; 1229 1230 bitmap += offsetof(struct mm_struct, cpu_bitmap); 1231 /* Skip cpu_bitmap */ 1232 bitmap += cpumask_size(); 1233 return (struct cpumask *)bitmap; 1234 } 1235 1236 /* Accessor for struct mm_struct's cidmask. */ 1237 static inline cpumask_t *mm_cidmask(struct mm_struct *mm) 1238 { 1239 unsigned long cid_bitmap = (unsigned long)mm_cpus_allowed(mm); 1240 1241 /* Skip mm_cpus_allowed */ 1242 cid_bitmap += cpumask_size(); 1243 return (struct cpumask *)cid_bitmap; 1244 } 1245 1246 static inline void mm_init_cid(struct mm_struct *mm, struct task_struct *p) 1247 { 1248 int i; 1249 1250 for_each_possible_cpu(i) { 1251 struct mm_cid *pcpu_cid = per_cpu_ptr(mm->pcpu_cid, i); 1252 1253 pcpu_cid->cid = MM_CID_UNSET; 1254 pcpu_cid->recent_cid = MM_CID_UNSET; 1255 pcpu_cid->time = 0; 1256 } 1257 mm->nr_cpus_allowed = p->nr_cpus_allowed; 1258 atomic_set(&mm->max_nr_cid, 0); 1259 raw_spin_lock_init(&mm->cpus_allowed_lock); 1260 cpumask_copy(mm_cpus_allowed(mm), &p->cpus_mask); 1261 cpumask_clear(mm_cidmask(mm)); 1262 } 1263 1264 static inline int mm_alloc_cid_noprof(struct mm_struct *mm, struct task_struct *p) 1265 { 1266 mm->pcpu_cid = alloc_percpu_noprof(struct mm_cid); 1267 if (!mm->pcpu_cid) 1268 return -ENOMEM; 1269 mm_init_cid(mm, p); 1270 return 0; 1271 } 1272 #define mm_alloc_cid(...) alloc_hooks(mm_alloc_cid_noprof(__VA_ARGS__)) 1273 1274 static inline void mm_destroy_cid(struct mm_struct *mm) 1275 { 1276 free_percpu(mm->pcpu_cid); 1277 mm->pcpu_cid = NULL; 1278 } 1279 1280 static inline unsigned int mm_cid_size(void) 1281 { 1282 return 2 * cpumask_size(); /* mm_cpus_allowed(), mm_cidmask(). */ 1283 } 1284 1285 static inline void mm_set_cpus_allowed(struct mm_struct *mm, const struct cpumask *cpumask) 1286 { 1287 struct cpumask *mm_allowed = mm_cpus_allowed(mm); 1288 1289 if (!mm) 1290 return; 1291 /* The mm_cpus_allowed is the union of each thread allowed CPUs masks. */ 1292 raw_spin_lock(&mm->cpus_allowed_lock); 1293 cpumask_or(mm_allowed, mm_allowed, cpumask); 1294 WRITE_ONCE(mm->nr_cpus_allowed, cpumask_weight(mm_allowed)); 1295 raw_spin_unlock(&mm->cpus_allowed_lock); 1296 } 1297 #else /* CONFIG_SCHED_MM_CID */ 1298 static inline void mm_init_cid(struct mm_struct *mm, struct task_struct *p) { } 1299 static inline int mm_alloc_cid(struct mm_struct *mm, struct task_struct *p) { return 0; } 1300 static inline void mm_destroy_cid(struct mm_struct *mm) { } 1301 1302 static inline unsigned int mm_cid_size(void) 1303 { 1304 return 0; 1305 } 1306 static inline void mm_set_cpus_allowed(struct mm_struct *mm, const struct cpumask *cpumask) { } 1307 #endif /* CONFIG_SCHED_MM_CID */ 1308 1309 struct mmu_gather; 1310 extern void tlb_gather_mmu(struct mmu_gather *tlb, struct mm_struct *mm); 1311 extern void tlb_gather_mmu_fullmm(struct mmu_gather *tlb, struct mm_struct *mm); 1312 extern void tlb_finish_mmu(struct mmu_gather *tlb); 1313 1314 struct vm_fault; 1315 1316 /** 1317 * typedef vm_fault_t - Return type for page fault handlers. 1318 * 1319 * Page fault handlers return a bitmask of %VM_FAULT values. 1320 */ 1321 typedef __bitwise unsigned int vm_fault_t; 1322 1323 /** 1324 * enum vm_fault_reason - Page fault handlers return a bitmask of 1325 * these values to tell the core VM what happened when handling the 1326 * fault. Used to decide whether a process gets delivered SIGBUS or 1327 * just gets major/minor fault counters bumped up. 1328 * 1329 * @VM_FAULT_OOM: Out Of Memory 1330 * @VM_FAULT_SIGBUS: Bad access 1331 * @VM_FAULT_MAJOR: Page read from storage 1332 * @VM_FAULT_HWPOISON: Hit poisoned small page 1333 * @VM_FAULT_HWPOISON_LARGE: Hit poisoned large page. Index encoded 1334 * in upper bits 1335 * @VM_FAULT_SIGSEGV: segmentation fault 1336 * @VM_FAULT_NOPAGE: ->fault installed the pte, not return page 1337 * @VM_FAULT_LOCKED: ->fault locked the returned page 1338 * @VM_FAULT_RETRY: ->fault blocked, must retry 1339 * @VM_FAULT_FALLBACK: huge page fault failed, fall back to small 1340 * @VM_FAULT_DONE_COW: ->fault has fully handled COW 1341 * @VM_FAULT_NEEDDSYNC: ->fault did not modify page tables and needs 1342 * fsync() to complete (for synchronous page faults 1343 * in DAX) 1344 * @VM_FAULT_COMPLETED: ->fault completed, meanwhile mmap lock released 1345 * @VM_FAULT_HINDEX_MASK: mask HINDEX value 1346 * 1347 */ 1348 enum vm_fault_reason { 1349 VM_FAULT_OOM = (__force vm_fault_t)0x000001, 1350 VM_FAULT_SIGBUS = (__force vm_fault_t)0x000002, 1351 VM_FAULT_MAJOR = (__force vm_fault_t)0x000004, 1352 VM_FAULT_HWPOISON = (__force vm_fault_t)0x000010, 1353 VM_FAULT_HWPOISON_LARGE = (__force vm_fault_t)0x000020, 1354 VM_FAULT_SIGSEGV = (__force vm_fault_t)0x000040, 1355 VM_FAULT_NOPAGE = (__force vm_fault_t)0x000100, 1356 VM_FAULT_LOCKED = (__force vm_fault_t)0x000200, 1357 VM_FAULT_RETRY = (__force vm_fault_t)0x000400, 1358 VM_FAULT_FALLBACK = (__force vm_fault_t)0x000800, 1359 VM_FAULT_DONE_COW = (__force vm_fault_t)0x001000, 1360 VM_FAULT_NEEDDSYNC = (__force vm_fault_t)0x002000, 1361 VM_FAULT_COMPLETED = (__force vm_fault_t)0x004000, 1362 VM_FAULT_HINDEX_MASK = (__force vm_fault_t)0x0f0000, 1363 }; 1364 1365 /* Encode hstate index for a hwpoisoned large page */ 1366 #define VM_FAULT_SET_HINDEX(x) ((__force vm_fault_t)((x) << 16)) 1367 #define VM_FAULT_GET_HINDEX(x) (((__force unsigned int)(x) >> 16) & 0xf) 1368 1369 #define VM_FAULT_ERROR (VM_FAULT_OOM | VM_FAULT_SIGBUS | \ 1370 VM_FAULT_SIGSEGV | VM_FAULT_HWPOISON | \ 1371 VM_FAULT_HWPOISON_LARGE | VM_FAULT_FALLBACK) 1372 1373 #define VM_FAULT_RESULT_TRACE \ 1374 { VM_FAULT_OOM, "OOM" }, \ 1375 { VM_FAULT_SIGBUS, "SIGBUS" }, \ 1376 { VM_FAULT_MAJOR, "MAJOR" }, \ 1377 { VM_FAULT_HWPOISON, "HWPOISON" }, \ 1378 { VM_FAULT_HWPOISON_LARGE, "HWPOISON_LARGE" }, \ 1379 { VM_FAULT_SIGSEGV, "SIGSEGV" }, \ 1380 { VM_FAULT_NOPAGE, "NOPAGE" }, \ 1381 { VM_FAULT_LOCKED, "LOCKED" }, \ 1382 { VM_FAULT_RETRY, "RETRY" }, \ 1383 { VM_FAULT_FALLBACK, "FALLBACK" }, \ 1384 { VM_FAULT_DONE_COW, "DONE_COW" }, \ 1385 { VM_FAULT_NEEDDSYNC, "NEEDDSYNC" }, \ 1386 { VM_FAULT_COMPLETED, "COMPLETED" } 1387 1388 struct vm_special_mapping { 1389 const char *name; /* The name, e.g. "[vdso]". */ 1390 1391 /* 1392 * If .fault is not provided, this points to a 1393 * NULL-terminated array of pages that back the special mapping. 1394 * 1395 * This must not be NULL unless .fault is provided. 1396 */ 1397 struct page **pages; 1398 1399 /* 1400 * If non-NULL, then this is called to resolve page faults 1401 * on the special mapping. If used, .pages is not checked. 1402 */ 1403 vm_fault_t (*fault)(const struct vm_special_mapping *sm, 1404 struct vm_area_struct *vma, 1405 struct vm_fault *vmf); 1406 1407 int (*mremap)(const struct vm_special_mapping *sm, 1408 struct vm_area_struct *new_vma); 1409 1410 void (*close)(const struct vm_special_mapping *sm, 1411 struct vm_area_struct *vma); 1412 }; 1413 1414 enum tlb_flush_reason { 1415 TLB_FLUSH_ON_TASK_SWITCH, 1416 TLB_REMOTE_SHOOTDOWN, 1417 TLB_LOCAL_SHOOTDOWN, 1418 TLB_LOCAL_MM_SHOOTDOWN, 1419 TLB_REMOTE_SEND_IPI, 1420 TLB_REMOTE_WRONG_CPU, 1421 NR_TLB_FLUSH_REASONS, 1422 }; 1423 1424 /** 1425 * enum fault_flag - Fault flag definitions. 1426 * @FAULT_FLAG_WRITE: Fault was a write fault. 1427 * @FAULT_FLAG_MKWRITE: Fault was mkwrite of existing PTE. 1428 * @FAULT_FLAG_ALLOW_RETRY: Allow to retry the fault if blocked. 1429 * @FAULT_FLAG_RETRY_NOWAIT: Don't drop mmap_lock and wait when retrying. 1430 * @FAULT_FLAG_KILLABLE: The fault task is in SIGKILL killable region. 1431 * @FAULT_FLAG_TRIED: The fault has been tried once. 1432 * @FAULT_FLAG_USER: The fault originated in userspace. 1433 * @FAULT_FLAG_REMOTE: The fault is not for current task/mm. 1434 * @FAULT_FLAG_INSTRUCTION: The fault was during an instruction fetch. 1435 * @FAULT_FLAG_INTERRUPTIBLE: The fault can be interrupted by non-fatal signals. 1436 * @FAULT_FLAG_UNSHARE: The fault is an unsharing request to break COW in a 1437 * COW mapping, making sure that an exclusive anon page is 1438 * mapped after the fault. 1439 * @FAULT_FLAG_ORIG_PTE_VALID: whether the fault has vmf->orig_pte cached. 1440 * We should only access orig_pte if this flag set. 1441 * @FAULT_FLAG_VMA_LOCK: The fault is handled under VMA lock. 1442 * 1443 * About @FAULT_FLAG_ALLOW_RETRY and @FAULT_FLAG_TRIED: we can specify 1444 * whether we would allow page faults to retry by specifying these two 1445 * fault flags correctly. Currently there can be three legal combinations: 1446 * 1447 * (a) ALLOW_RETRY and !TRIED: this means the page fault allows retry, and 1448 * this is the first try 1449 * 1450 * (b) ALLOW_RETRY and TRIED: this means the page fault allows retry, and 1451 * we've already tried at least once 1452 * 1453 * (c) !ALLOW_RETRY and !TRIED: this means the page fault does not allow retry 1454 * 1455 * The unlisted combination (!ALLOW_RETRY && TRIED) is illegal and should never 1456 * be used. Note that page faults can be allowed to retry for multiple times, 1457 * in which case we'll have an initial fault with flags (a) then later on 1458 * continuous faults with flags (b). We should always try to detect pending 1459 * signals before a retry to make sure the continuous page faults can still be 1460 * interrupted if necessary. 1461 * 1462 * The combination FAULT_FLAG_WRITE|FAULT_FLAG_UNSHARE is illegal. 1463 * FAULT_FLAG_UNSHARE is ignored and treated like an ordinary read fault when 1464 * applied to mappings that are not COW mappings. 1465 */ 1466 enum fault_flag { 1467 FAULT_FLAG_WRITE = 1 << 0, 1468 FAULT_FLAG_MKWRITE = 1 << 1, 1469 FAULT_FLAG_ALLOW_RETRY = 1 << 2, 1470 FAULT_FLAG_RETRY_NOWAIT = 1 << 3, 1471 FAULT_FLAG_KILLABLE = 1 << 4, 1472 FAULT_FLAG_TRIED = 1 << 5, 1473 FAULT_FLAG_USER = 1 << 6, 1474 FAULT_FLAG_REMOTE = 1 << 7, 1475 FAULT_FLAG_INSTRUCTION = 1 << 8, 1476 FAULT_FLAG_INTERRUPTIBLE = 1 << 9, 1477 FAULT_FLAG_UNSHARE = 1 << 10, 1478 FAULT_FLAG_ORIG_PTE_VALID = 1 << 11, 1479 FAULT_FLAG_VMA_LOCK = 1 << 12, 1480 }; 1481 1482 typedef unsigned int __bitwise zap_flags_t; 1483 1484 /* Flags for clear_young_dirty_ptes(). */ 1485 typedef int __bitwise cydp_t; 1486 1487 /* Clear the access bit */ 1488 #define CYDP_CLEAR_YOUNG ((__force cydp_t)BIT(0)) 1489 1490 /* Clear the dirty bit */ 1491 #define CYDP_CLEAR_DIRTY ((__force cydp_t)BIT(1)) 1492 1493 /* 1494 * FOLL_PIN and FOLL_LONGTERM may be used in various combinations with each 1495 * other. Here is what they mean, and how to use them: 1496 * 1497 * 1498 * FIXME: For pages which are part of a filesystem, mappings are subject to the 1499 * lifetime enforced by the filesystem and we need guarantees that longterm 1500 * users like RDMA and V4L2 only establish mappings which coordinate usage with 1501 * the filesystem. Ideas for this coordination include revoking the longterm 1502 * pin, delaying writeback, bounce buffer page writeback, etc. As FS DAX was 1503 * added after the problem with filesystems was found FS DAX VMAs are 1504 * specifically failed. Filesystem pages are still subject to bugs and use of 1505 * FOLL_LONGTERM should be avoided on those pages. 1506 * 1507 * In the CMA case: long term pins in a CMA region would unnecessarily fragment 1508 * that region. And so, CMA attempts to migrate the page before pinning, when 1509 * FOLL_LONGTERM is specified. 1510 * 1511 * FOLL_PIN indicates that a special kind of tracking (not just page->_refcount, 1512 * but an additional pin counting system) will be invoked. This is intended for 1513 * anything that gets a page reference and then touches page data (for example, 1514 * Direct IO). This lets the filesystem know that some non-file-system entity is 1515 * potentially changing the pages' data. In contrast to FOLL_GET (whose pages 1516 * are released via put_page()), FOLL_PIN pages must be released, ultimately, by 1517 * a call to unpin_user_page(). 1518 * 1519 * FOLL_PIN is similar to FOLL_GET: both of these pin pages. They use different 1520 * and separate refcounting mechanisms, however, and that means that each has 1521 * its own acquire and release mechanisms: 1522 * 1523 * FOLL_GET: get_user_pages*() to acquire, and put_page() to release. 1524 * 1525 * FOLL_PIN: pin_user_pages*() to acquire, and unpin_user_pages to release. 1526 * 1527 * FOLL_PIN and FOLL_GET are mutually exclusive for a given function call. 1528 * (The underlying pages may experience both FOLL_GET-based and FOLL_PIN-based 1529 * calls applied to them, and that's perfectly OK. This is a constraint on the 1530 * callers, not on the pages.) 1531 * 1532 * FOLL_PIN should be set internally by the pin_user_pages*() APIs, never 1533 * directly by the caller. That's in order to help avoid mismatches when 1534 * releasing pages: get_user_pages*() pages must be released via put_page(), 1535 * while pin_user_pages*() pages must be released via unpin_user_page(). 1536 * 1537 * Please see Documentation/core-api/pin_user_pages.rst for more information. 1538 */ 1539 1540 enum { 1541 /* check pte is writable */ 1542 FOLL_WRITE = 1 << 0, 1543 /* do get_page on page */ 1544 FOLL_GET = 1 << 1, 1545 /* give error on hole if it would be zero */ 1546 FOLL_DUMP = 1 << 2, 1547 /* get_user_pages read/write w/o permission */ 1548 FOLL_FORCE = 1 << 3, 1549 /* 1550 * if a disk transfer is needed, start the IO and return without waiting 1551 * upon it 1552 */ 1553 FOLL_NOWAIT = 1 << 4, 1554 /* do not fault in pages */ 1555 FOLL_NOFAULT = 1 << 5, 1556 /* check page is hwpoisoned */ 1557 FOLL_HWPOISON = 1 << 6, 1558 /* don't do file mappings */ 1559 FOLL_ANON = 1 << 7, 1560 /* 1561 * FOLL_LONGTERM indicates that the page will be held for an indefinite 1562 * time period _often_ under userspace control. This is in contrast to 1563 * iov_iter_get_pages(), whose usages are transient. 1564 */ 1565 FOLL_LONGTERM = 1 << 8, 1566 /* split huge pmd before returning */ 1567 FOLL_SPLIT_PMD = 1 << 9, 1568 /* allow returning PCI P2PDMA pages */ 1569 FOLL_PCI_P2PDMA = 1 << 10, 1570 /* allow interrupts from generic signals */ 1571 FOLL_INTERRUPTIBLE = 1 << 11, 1572 /* 1573 * Always honor (trigger) NUMA hinting faults. 1574 * 1575 * FOLL_WRITE implicitly honors NUMA hinting faults because a 1576 * PROT_NONE-mapped page is not writable (exceptions with FOLL_FORCE 1577 * apply). get_user_pages_fast_only() always implicitly honors NUMA 1578 * hinting faults. 1579 */ 1580 FOLL_HONOR_NUMA_FAULT = 1 << 12, 1581 1582 /* See also internal only FOLL flags in mm/internal.h */ 1583 }; 1584 1585 /* mm flags */ 1586 1587 /* 1588 * The first two bits represent core dump modes for set-user-ID, 1589 * the modes are SUID_DUMP_* defined in linux/sched/coredump.h 1590 */ 1591 #define MMF_DUMPABLE_BITS 2 1592 #define MMF_DUMPABLE_MASK ((1 << MMF_DUMPABLE_BITS) - 1) 1593 /* coredump filter bits */ 1594 #define MMF_DUMP_ANON_PRIVATE 2 1595 #define MMF_DUMP_ANON_SHARED 3 1596 #define MMF_DUMP_MAPPED_PRIVATE 4 1597 #define MMF_DUMP_MAPPED_SHARED 5 1598 #define MMF_DUMP_ELF_HEADERS 6 1599 #define MMF_DUMP_HUGETLB_PRIVATE 7 1600 #define MMF_DUMP_HUGETLB_SHARED 8 1601 #define MMF_DUMP_DAX_PRIVATE 9 1602 #define MMF_DUMP_DAX_SHARED 10 1603 1604 #define MMF_DUMP_FILTER_SHIFT MMF_DUMPABLE_BITS 1605 #define MMF_DUMP_FILTER_BITS 9 1606 #define MMF_DUMP_FILTER_MASK \ 1607 (((1 << MMF_DUMP_FILTER_BITS) - 1) << MMF_DUMP_FILTER_SHIFT) 1608 #define MMF_DUMP_FILTER_DEFAULT \ 1609 ((1 << MMF_DUMP_ANON_PRIVATE) | (1 << MMF_DUMP_ANON_SHARED) |\ 1610 (1 << MMF_DUMP_HUGETLB_PRIVATE) | MMF_DUMP_MASK_DEFAULT_ELF) 1611 1612 #ifdef CONFIG_CORE_DUMP_DEFAULT_ELF_HEADERS 1613 # define MMF_DUMP_MASK_DEFAULT_ELF (1 << MMF_DUMP_ELF_HEADERS) 1614 #else 1615 # define MMF_DUMP_MASK_DEFAULT_ELF 0 1616 #endif 1617 /* leave room for more dump flags */ 1618 #define MMF_VM_MERGEABLE 16 /* KSM may merge identical pages */ 1619 #define MMF_VM_HUGEPAGE 17 /* set when mm is available for khugepaged */ 1620 1621 /* 1622 * This one-shot flag is dropped due to necessity of changing exe once again 1623 * on NFS restore 1624 */ 1625 //#define MMF_EXE_FILE_CHANGED 18 /* see prctl_set_mm_exe_file() */ 1626 1627 #define MMF_HAS_UPROBES 19 /* has uprobes */ 1628 #define MMF_RECALC_UPROBES 20 /* MMF_HAS_UPROBES can be wrong */ 1629 #define MMF_OOM_SKIP 21 /* mm is of no interest for the OOM killer */ 1630 #define MMF_UNSTABLE 22 /* mm is unstable for copy_from_user */ 1631 #define MMF_HUGE_ZERO_PAGE 23 /* mm has ever used the global huge zero page */ 1632 #define MMF_DISABLE_THP 24 /* disable THP for all VMAs */ 1633 #define MMF_DISABLE_THP_MASK (1 << MMF_DISABLE_THP) 1634 #define MMF_OOM_REAP_QUEUED 25 /* mm was queued for oom_reaper */ 1635 #define MMF_MULTIPROCESS 26 /* mm is shared between processes */ 1636 /* 1637 * MMF_HAS_PINNED: Whether this mm has pinned any pages. This can be either 1638 * replaced in the future by mm.pinned_vm when it becomes stable, or grow into 1639 * a counter on its own. We're aggresive on this bit for now: even if the 1640 * pinned pages were unpinned later on, we'll still keep this bit set for the 1641 * lifecycle of this mm, just for simplicity. 1642 */ 1643 #define MMF_HAS_PINNED 27 /* FOLL_PIN has run, never cleared */ 1644 1645 #define MMF_HAS_MDWE 28 1646 #define MMF_HAS_MDWE_MASK (1 << MMF_HAS_MDWE) 1647 1648 1649 #define MMF_HAS_MDWE_NO_INHERIT 29 1650 1651 #define MMF_VM_MERGE_ANY 30 1652 #define MMF_VM_MERGE_ANY_MASK (1 << MMF_VM_MERGE_ANY) 1653 1654 #define MMF_TOPDOWN 31 /* mm searches top down by default */ 1655 #define MMF_TOPDOWN_MASK (1 << MMF_TOPDOWN) 1656 1657 #define MMF_INIT_MASK (MMF_DUMPABLE_MASK | MMF_DUMP_FILTER_MASK |\ 1658 MMF_DISABLE_THP_MASK | MMF_HAS_MDWE_MASK |\ 1659 MMF_VM_MERGE_ANY_MASK | MMF_TOPDOWN_MASK) 1660 1661 static inline unsigned long mmf_init_flags(unsigned long flags) 1662 { 1663 if (flags & (1UL << MMF_HAS_MDWE_NO_INHERIT)) 1664 flags &= ~((1UL << MMF_HAS_MDWE) | 1665 (1UL << MMF_HAS_MDWE_NO_INHERIT)); 1666 return flags & MMF_INIT_MASK; 1667 } 1668 1669 #endif /* _LINUX_MM_TYPES_H */ 1670