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/rwsem.h> 13 #include <linux/completion.h> 14 #include <linux/cpumask.h> 15 #include <linux/uprobes.h> 16 #include <linux/rcupdate.h> 17 #include <linux/page-flags-layout.h> 18 #include <linux/workqueue.h> 19 #include <linux/seqlock.h> 20 21 #include <asm/mmu.h> 22 23 #ifndef AT_VECTOR_SIZE_ARCH 24 #define AT_VECTOR_SIZE_ARCH 0 25 #endif 26 #define AT_VECTOR_SIZE (2*(AT_VECTOR_SIZE_ARCH + AT_VECTOR_SIZE_BASE + 1)) 27 28 #define INIT_PASID 0 29 30 struct address_space; 31 struct mem_cgroup; 32 33 /* 34 * Each physical page in the system has a struct page associated with 35 * it to keep track of whatever it is we are using the page for at the 36 * moment. Note that we have no way to track which tasks are using 37 * a page, though if it is a pagecache page, rmap structures can tell us 38 * who is mapping it. 39 * 40 * If you allocate the page using alloc_pages(), you can use some of the 41 * space in struct page for your own purposes. The five words in the main 42 * union are available, except for bit 0 of the first word which must be 43 * kept clear. Many users use this word to store a pointer to an object 44 * which is guaranteed to be aligned. If you use the same storage as 45 * page->mapping, you must restore it to NULL before freeing the page. 46 * 47 * If your page will not be mapped to userspace, you can also use the four 48 * bytes in the mapcount union, but you must call page_mapcount_reset() 49 * before freeing it. 50 * 51 * If you want to use the refcount field, it must be used in such a way 52 * that other CPUs temporarily incrementing and then decrementing the 53 * refcount does not cause problems. On receiving the page from 54 * alloc_pages(), the refcount will be positive. 55 * 56 * If you allocate pages of order > 0, you can use some of the fields 57 * in each subpage, but you may need to restore some of their values 58 * afterwards. 59 * 60 * SLUB uses cmpxchg_double() to atomically update its freelist and counters. 61 * That requires that freelist & counters in struct slab be adjacent and 62 * double-word aligned. Because struct slab currently just reinterprets the 63 * bits of struct page, we align all struct pages to double-word boundaries, 64 * and ensure that 'freelist' is aligned within struct slab. 65 */ 66 #ifdef CONFIG_HAVE_ALIGNED_STRUCT_PAGE 67 #define _struct_page_alignment __aligned(2 * sizeof(unsigned long)) 68 #else 69 #define _struct_page_alignment 70 #endif 71 72 struct page { 73 unsigned long flags; /* Atomic flags, some possibly 74 * updated asynchronously */ 75 /* 76 * Five words (20/40 bytes) are available in this union. 77 * WARNING: bit 0 of the first word is used for PageTail(). That 78 * means the other users of this union MUST NOT use the bit to 79 * avoid collision and false-positive PageTail(). 80 */ 81 union { 82 struct { /* Page cache and anonymous pages */ 83 /** 84 * @lru: Pageout list, eg. active_list protected by 85 * lruvec->lru_lock. Sometimes used as a generic list 86 * by the page owner. 87 */ 88 union { 89 struct list_head lru; 90 91 /* Or, for the Unevictable "LRU list" slot */ 92 struct { 93 /* Always even, to negate PageTail */ 94 void *__filler; 95 /* Count page's or folio's mlocks */ 96 unsigned int mlock_count; 97 }; 98 99 /* Or, free page */ 100 struct list_head buddy_list; 101 struct list_head pcp_list; 102 }; 103 /* See page-flags.h for PAGE_MAPPING_FLAGS */ 104 struct address_space *mapping; 105 pgoff_t index; /* Our offset within mapping. */ 106 /** 107 * @private: Mapping-private opaque data. 108 * Usually used for buffer_heads if PagePrivate. 109 * Used for swp_entry_t if PageSwapCache. 110 * Indicates order in the buddy system if PageBuddy. 111 */ 112 unsigned long private; 113 }; 114 struct { /* page_pool used by netstack */ 115 /** 116 * @pp_magic: magic value to avoid recycling non 117 * page_pool allocated pages. 118 */ 119 unsigned long pp_magic; 120 struct page_pool *pp; 121 unsigned long _pp_mapping_pad; 122 unsigned long dma_addr; 123 union { 124 /** 125 * dma_addr_upper: might require a 64-bit 126 * value on 32-bit architectures. 127 */ 128 unsigned long dma_addr_upper; 129 /** 130 * For frag page support, not supported in 131 * 32-bit architectures with 64-bit DMA. 132 */ 133 atomic_long_t pp_frag_count; 134 }; 135 }; 136 struct { /* Tail pages of compound page */ 137 unsigned long compound_head; /* Bit zero is set */ 138 139 /* First tail page only */ 140 unsigned char compound_dtor; 141 unsigned char compound_order; 142 atomic_t compound_mapcount; 143 atomic_t compound_pincount; 144 #ifdef CONFIG_64BIT 145 unsigned int compound_nr; /* 1 << compound_order */ 146 #endif 147 }; 148 struct { /* Second tail page of compound page */ 149 unsigned long _compound_pad_1; /* compound_head */ 150 unsigned long _compound_pad_2; 151 /* For both global and memcg */ 152 struct list_head deferred_list; 153 }; 154 struct { /* Page table pages */ 155 unsigned long _pt_pad_1; /* compound_head */ 156 pgtable_t pmd_huge_pte; /* protected by page->ptl */ 157 unsigned long _pt_pad_2; /* mapping */ 158 union { 159 struct mm_struct *pt_mm; /* x86 pgds only */ 160 atomic_t pt_frag_refcount; /* powerpc */ 161 }; 162 #if ALLOC_SPLIT_PTLOCKS 163 spinlock_t *ptl; 164 #else 165 spinlock_t ptl; 166 #endif 167 }; 168 struct { /* ZONE_DEVICE pages */ 169 /** @pgmap: Points to the hosting device page map. */ 170 struct dev_pagemap *pgmap; 171 void *zone_device_data; 172 /* 173 * ZONE_DEVICE private pages are counted as being 174 * mapped so the next 3 words hold the mapping, index, 175 * and private fields from the source anonymous or 176 * page cache page while the page is migrated to device 177 * private memory. 178 * ZONE_DEVICE MEMORY_DEVICE_FS_DAX pages also 179 * use the mapping, index, and private fields when 180 * pmem backed DAX files are mapped. 181 */ 182 }; 183 184 /** @rcu_head: You can use this to free a page by RCU. */ 185 struct rcu_head rcu_head; 186 }; 187 188 union { /* This union is 4 bytes in size. */ 189 /* 190 * If the page can be mapped to userspace, encodes the number 191 * of times this page is referenced by a page table. 192 */ 193 atomic_t _mapcount; 194 195 /* 196 * If the page is neither PageSlab nor mappable to userspace, 197 * the value stored here may help determine what this page 198 * is used for. See page-flags.h for a list of page types 199 * which are currently stored here. 200 */ 201 unsigned int page_type; 202 }; 203 204 /* Usage count. *DO NOT USE DIRECTLY*. See page_ref.h */ 205 atomic_t _refcount; 206 207 #ifdef CONFIG_MEMCG 208 unsigned long memcg_data; 209 #endif 210 211 /* 212 * On machines where all RAM is mapped into kernel address space, 213 * we can simply calculate the virtual address. On machines with 214 * highmem some memory is mapped into kernel virtual memory 215 * dynamically, so we need a place to store that address. 216 * Note that this field could be 16 bits on x86 ... ;) 217 * 218 * Architectures with slow multiplication can define 219 * WANT_PAGE_VIRTUAL in asm/page.h 220 */ 221 #if defined(WANT_PAGE_VIRTUAL) 222 void *virtual; /* Kernel virtual address (NULL if 223 not kmapped, ie. highmem) */ 224 #endif /* WANT_PAGE_VIRTUAL */ 225 226 #ifdef LAST_CPUPID_NOT_IN_PAGE_FLAGS 227 int _last_cpupid; 228 #endif 229 } _struct_page_alignment; 230 231 /** 232 * struct folio - Represents a contiguous set of bytes. 233 * @flags: Identical to the page flags. 234 * @lru: Least Recently Used list; tracks how recently this folio was used. 235 * @mlock_count: Number of times this folio has been pinned by mlock(). 236 * @mapping: The file this page belongs to, or refers to the anon_vma for 237 * anonymous memory. 238 * @index: Offset within the file, in units of pages. For anonymous memory, 239 * this is the index from the beginning of the mmap. 240 * @private: Filesystem per-folio data (see folio_attach_private()). 241 * Used for swp_entry_t if folio_test_swapcache(). 242 * @_mapcount: Do not access this member directly. Use folio_mapcount() to 243 * find out how many times this folio is mapped by userspace. 244 * @_refcount: Do not access this member directly. Use folio_ref_count() 245 * to find how many references there are to this folio. 246 * @memcg_data: Memory Control Group data. 247 * 248 * A folio is a physically, virtually and logically contiguous set 249 * of bytes. It is a power-of-two in size, and it is aligned to that 250 * same power-of-two. It is at least as large as %PAGE_SIZE. If it is 251 * in the page cache, it is at a file offset which is a multiple of that 252 * power-of-two. It may be mapped into userspace at an address which is 253 * at an arbitrary page offset, but its kernel virtual address is aligned 254 * to its size. 255 */ 256 struct folio { 257 /* private: don't document the anon union */ 258 union { 259 struct { 260 /* public: */ 261 unsigned long flags; 262 union { 263 struct list_head lru; 264 /* private: avoid cluttering the output */ 265 struct { 266 void *__filler; 267 /* public: */ 268 unsigned int mlock_count; 269 /* private: */ 270 }; 271 /* public: */ 272 }; 273 struct address_space *mapping; 274 pgoff_t index; 275 void *private; 276 atomic_t _mapcount; 277 atomic_t _refcount; 278 #ifdef CONFIG_MEMCG 279 unsigned long memcg_data; 280 #endif 281 /* private: the union with struct page is transitional */ 282 }; 283 struct page page; 284 }; 285 }; 286 287 static_assert(sizeof(struct page) == sizeof(struct folio)); 288 #define FOLIO_MATCH(pg, fl) \ 289 static_assert(offsetof(struct page, pg) == offsetof(struct folio, fl)) 290 FOLIO_MATCH(flags, flags); 291 FOLIO_MATCH(lru, lru); 292 FOLIO_MATCH(mapping, mapping); 293 FOLIO_MATCH(compound_head, lru); 294 FOLIO_MATCH(index, index); 295 FOLIO_MATCH(private, private); 296 FOLIO_MATCH(_mapcount, _mapcount); 297 FOLIO_MATCH(_refcount, _refcount); 298 #ifdef CONFIG_MEMCG 299 FOLIO_MATCH(memcg_data, memcg_data); 300 #endif 301 #undef FOLIO_MATCH 302 303 static inline atomic_t *folio_mapcount_ptr(struct folio *folio) 304 { 305 struct page *tail = &folio->page + 1; 306 return &tail->compound_mapcount; 307 } 308 309 static inline atomic_t *compound_mapcount_ptr(struct page *page) 310 { 311 return &page[1].compound_mapcount; 312 } 313 314 static inline atomic_t *compound_pincount_ptr(struct page *page) 315 { 316 return &page[1].compound_pincount; 317 } 318 319 /* 320 * Used for sizing the vmemmap region on some architectures 321 */ 322 #define STRUCT_PAGE_MAX_SHIFT (order_base_2(sizeof(struct page))) 323 324 #define PAGE_FRAG_CACHE_MAX_SIZE __ALIGN_MASK(32768, ~PAGE_MASK) 325 #define PAGE_FRAG_CACHE_MAX_ORDER get_order(PAGE_FRAG_CACHE_MAX_SIZE) 326 327 /* 328 * page_private can be used on tail pages. However, PagePrivate is only 329 * checked by the VM on the head page. So page_private on the tail pages 330 * should be used for data that's ancillary to the head page (eg attaching 331 * buffer heads to tail pages after attaching buffer heads to the head page) 332 */ 333 #define page_private(page) ((page)->private) 334 335 static inline void set_page_private(struct page *page, unsigned long private) 336 { 337 page->private = private; 338 } 339 340 static inline void *folio_get_private(struct folio *folio) 341 { 342 return folio->private; 343 } 344 345 struct page_frag_cache { 346 void * va; 347 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE) 348 __u16 offset; 349 __u16 size; 350 #else 351 __u32 offset; 352 #endif 353 /* we maintain a pagecount bias, so that we dont dirty cache line 354 * containing page->_refcount every time we allocate a fragment. 355 */ 356 unsigned int pagecnt_bias; 357 bool pfmemalloc; 358 }; 359 360 typedef unsigned long vm_flags_t; 361 362 /* 363 * A region containing a mapping of a non-memory backed file under NOMMU 364 * conditions. These are held in a global tree and are pinned by the VMAs that 365 * map parts of them. 366 */ 367 struct vm_region { 368 struct rb_node vm_rb; /* link in global region tree */ 369 vm_flags_t vm_flags; /* VMA vm_flags */ 370 unsigned long vm_start; /* start address of region */ 371 unsigned long vm_end; /* region initialised to here */ 372 unsigned long vm_top; /* region allocated to here */ 373 unsigned long vm_pgoff; /* the offset in vm_file corresponding to vm_start */ 374 struct file *vm_file; /* the backing file or NULL */ 375 376 int vm_usage; /* region usage count (access under nommu_region_sem) */ 377 bool vm_icache_flushed : 1; /* true if the icache has been flushed for 378 * this region */ 379 }; 380 381 #ifdef CONFIG_USERFAULTFD 382 #define NULL_VM_UFFD_CTX ((struct vm_userfaultfd_ctx) { NULL, }) 383 struct vm_userfaultfd_ctx { 384 struct userfaultfd_ctx *ctx; 385 }; 386 #else /* CONFIG_USERFAULTFD */ 387 #define NULL_VM_UFFD_CTX ((struct vm_userfaultfd_ctx) {}) 388 struct vm_userfaultfd_ctx {}; 389 #endif /* CONFIG_USERFAULTFD */ 390 391 struct anon_vma_name { 392 struct kref kref; 393 /* The name needs to be at the end because it is dynamically sized. */ 394 char name[]; 395 }; 396 397 /* 398 * This struct describes a virtual memory area. There is one of these 399 * per VM-area/task. A VM area is any part of the process virtual memory 400 * space that has a special rule for the page-fault handlers (ie a shared 401 * library, the executable area etc). 402 */ 403 struct vm_area_struct { 404 /* The first cache line has the info for VMA tree walking. */ 405 406 unsigned long vm_start; /* Our start address within vm_mm. */ 407 unsigned long vm_end; /* The first byte after our end address 408 within vm_mm. */ 409 410 /* linked list of VM areas per task, sorted by address */ 411 struct vm_area_struct *vm_next, *vm_prev; 412 413 struct rb_node vm_rb; 414 415 /* 416 * Largest free memory gap in bytes to the left of this VMA. 417 * Either between this VMA and vma->vm_prev, or between one of the 418 * VMAs below us in the VMA rbtree and its ->vm_prev. This helps 419 * get_unmapped_area find a free area of the right size. 420 */ 421 unsigned long rb_subtree_gap; 422 423 /* Second cache line starts here. */ 424 425 struct mm_struct *vm_mm; /* The address space we belong to. */ 426 427 /* 428 * Access permissions of this VMA. 429 * See vmf_insert_mixed_prot() for discussion. 430 */ 431 pgprot_t vm_page_prot; 432 unsigned long vm_flags; /* Flags, see mm.h. */ 433 434 /* 435 * For areas with an address space and backing store, 436 * linkage into the address_space->i_mmap interval tree. 437 * 438 * For private anonymous mappings, a pointer to a null terminated string 439 * containing the name given to the vma, or NULL if unnamed. 440 */ 441 442 union { 443 struct { 444 struct rb_node rb; 445 unsigned long rb_subtree_last; 446 } shared; 447 /* 448 * Serialized by mmap_sem. Never use directly because it is 449 * valid only when vm_file is NULL. Use anon_vma_name instead. 450 */ 451 struct anon_vma_name *anon_name; 452 }; 453 454 /* 455 * A file's MAP_PRIVATE vma can be in both i_mmap tree and anon_vma 456 * list, after a COW of one of the file pages. A MAP_SHARED vma 457 * can only be in the i_mmap tree. An anonymous MAP_PRIVATE, stack 458 * or brk vma (with NULL file) can only be in an anon_vma list. 459 */ 460 struct list_head anon_vma_chain; /* Serialized by mmap_lock & 461 * page_table_lock */ 462 struct anon_vma *anon_vma; /* Serialized by page_table_lock */ 463 464 /* Function pointers to deal with this struct. */ 465 const struct vm_operations_struct *vm_ops; 466 467 /* Information about our backing store: */ 468 unsigned long vm_pgoff; /* Offset (within vm_file) in PAGE_SIZE 469 units */ 470 struct file * vm_file; /* File we map to (can be NULL). */ 471 void * vm_private_data; /* was vm_pte (shared mem) */ 472 473 #ifdef CONFIG_SWAP 474 atomic_long_t swap_readahead_info; 475 #endif 476 #ifndef CONFIG_MMU 477 struct vm_region *vm_region; /* NOMMU mapping region */ 478 #endif 479 #ifdef CONFIG_NUMA 480 struct mempolicy *vm_policy; /* NUMA policy for the VMA */ 481 #endif 482 struct vm_userfaultfd_ctx vm_userfaultfd_ctx; 483 } __randomize_layout; 484 485 struct kioctx_table; 486 struct mm_struct { 487 struct { 488 struct vm_area_struct *mmap; /* list of VMAs */ 489 struct rb_root mm_rb; 490 u64 vmacache_seqnum; /* per-thread vmacache */ 491 #ifdef CONFIG_MMU 492 unsigned long (*get_unmapped_area) (struct file *filp, 493 unsigned long addr, unsigned long len, 494 unsigned long pgoff, unsigned long flags); 495 #endif 496 unsigned long mmap_base; /* base of mmap area */ 497 unsigned long mmap_legacy_base; /* base of mmap area in bottom-up allocations */ 498 #ifdef CONFIG_HAVE_ARCH_COMPAT_MMAP_BASES 499 /* Base addresses for compatible mmap() */ 500 unsigned long mmap_compat_base; 501 unsigned long mmap_compat_legacy_base; 502 #endif 503 unsigned long task_size; /* size of task vm space */ 504 unsigned long highest_vm_end; /* highest vma end address */ 505 pgd_t * pgd; 506 507 #ifdef CONFIG_MEMBARRIER 508 /** 509 * @membarrier_state: Flags controlling membarrier behavior. 510 * 511 * This field is close to @pgd to hopefully fit in the same 512 * cache-line, which needs to be touched by switch_mm(). 513 */ 514 atomic_t membarrier_state; 515 #endif 516 517 /** 518 * @mm_users: The number of users including userspace. 519 * 520 * Use mmget()/mmget_not_zero()/mmput() to modify. When this 521 * drops to 0 (i.e. when the task exits and there are no other 522 * temporary reference holders), we also release a reference on 523 * @mm_count (which may then free the &struct mm_struct if 524 * @mm_count also drops to 0). 525 */ 526 atomic_t mm_users; 527 528 /** 529 * @mm_count: The number of references to &struct mm_struct 530 * (@mm_users count as 1). 531 * 532 * Use mmgrab()/mmdrop() to modify. When this drops to 0, the 533 * &struct mm_struct is freed. 534 */ 535 atomic_t mm_count; 536 537 #ifdef CONFIG_MMU 538 atomic_long_t pgtables_bytes; /* PTE page table pages */ 539 #endif 540 int map_count; /* number of VMAs */ 541 542 spinlock_t page_table_lock; /* Protects page tables and some 543 * counters 544 */ 545 /* 546 * With some kernel config, the current mmap_lock's offset 547 * inside 'mm_struct' is at 0x120, which is very optimal, as 548 * its two hot fields 'count' and 'owner' sit in 2 different 549 * cachelines, and when mmap_lock is highly contended, both 550 * of the 2 fields will be accessed frequently, current layout 551 * will help to reduce cache bouncing. 552 * 553 * So please be careful with adding new fields before 554 * mmap_lock, which can easily push the 2 fields into one 555 * cacheline. 556 */ 557 struct rw_semaphore mmap_lock; 558 559 struct list_head mmlist; /* List of maybe swapped mm's. These 560 * are globally strung together off 561 * init_mm.mmlist, and are protected 562 * by mmlist_lock 563 */ 564 565 566 unsigned long hiwater_rss; /* High-watermark of RSS usage */ 567 unsigned long hiwater_vm; /* High-water virtual memory usage */ 568 569 unsigned long total_vm; /* Total pages mapped */ 570 unsigned long locked_vm; /* Pages that have PG_mlocked set */ 571 atomic64_t pinned_vm; /* Refcount permanently increased */ 572 unsigned long data_vm; /* VM_WRITE & ~VM_SHARED & ~VM_STACK */ 573 unsigned long exec_vm; /* VM_EXEC & ~VM_WRITE & ~VM_STACK */ 574 unsigned long stack_vm; /* VM_STACK */ 575 unsigned long def_flags; 576 577 /** 578 * @write_protect_seq: Locked when any thread is write 579 * protecting pages mapped by this mm to enforce a later COW, 580 * for instance during page table copying for fork(). 581 */ 582 seqcount_t write_protect_seq; 583 584 spinlock_t arg_lock; /* protect the below fields */ 585 586 unsigned long start_code, end_code, start_data, end_data; 587 unsigned long start_brk, brk, start_stack; 588 unsigned long arg_start, arg_end, env_start, env_end; 589 590 unsigned long saved_auxv[AT_VECTOR_SIZE]; /* for /proc/PID/auxv */ 591 592 /* 593 * Special counters, in some configurations protected by the 594 * page_table_lock, in other configurations by being atomic. 595 */ 596 struct mm_rss_stat rss_stat; 597 598 struct linux_binfmt *binfmt; 599 600 /* Architecture-specific MM context */ 601 mm_context_t context; 602 603 unsigned long flags; /* Must use atomic bitops to access */ 604 605 #ifdef CONFIG_AIO 606 spinlock_t ioctx_lock; 607 struct kioctx_table __rcu *ioctx_table; 608 #endif 609 #ifdef CONFIG_MEMCG 610 /* 611 * "owner" points to a task that is regarded as the canonical 612 * user/owner of this mm. All of the following must be true in 613 * order for it to be changed: 614 * 615 * current == mm->owner 616 * current->mm != mm 617 * new_owner->mm == mm 618 * new_owner->alloc_lock is held 619 */ 620 struct task_struct __rcu *owner; 621 #endif 622 struct user_namespace *user_ns; 623 624 /* store ref to file /proc/<pid>/exe symlink points to */ 625 struct file __rcu *exe_file; 626 #ifdef CONFIG_MMU_NOTIFIER 627 struct mmu_notifier_subscriptions *notifier_subscriptions; 628 #endif 629 #if defined(CONFIG_TRANSPARENT_HUGEPAGE) && !USE_SPLIT_PMD_PTLOCKS 630 pgtable_t pmd_huge_pte; /* protected by page_table_lock */ 631 #endif 632 #ifdef CONFIG_NUMA_BALANCING 633 /* 634 * numa_next_scan is the next time that the PTEs will be marked 635 * pte_numa. NUMA hinting faults will gather statistics and 636 * migrate pages to new nodes if necessary. 637 */ 638 unsigned long numa_next_scan; 639 640 /* Restart point for scanning and setting pte_numa */ 641 unsigned long numa_scan_offset; 642 643 /* numa_scan_seq prevents two threads setting pte_numa */ 644 int numa_scan_seq; 645 #endif 646 /* 647 * An operation with batched TLB flushing is going on. Anything 648 * that can move process memory needs to flush the TLB when 649 * moving a PROT_NONE or PROT_NUMA mapped page. 650 */ 651 atomic_t tlb_flush_pending; 652 #ifdef CONFIG_ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH 653 /* See flush_tlb_batched_pending() */ 654 atomic_t tlb_flush_batched; 655 #endif 656 struct uprobes_state uprobes_state; 657 #ifdef CONFIG_PREEMPT_RT 658 struct rcu_head delayed_drop; 659 #endif 660 #ifdef CONFIG_HUGETLB_PAGE 661 atomic_long_t hugetlb_usage; 662 #endif 663 struct work_struct async_put_work; 664 665 #ifdef CONFIG_IOMMU_SVA 666 u32 pasid; 667 #endif 668 #ifdef CONFIG_KSM 669 /* 670 * Represent how many pages of this process are involved in KSM 671 * merging. 672 */ 673 unsigned long ksm_merging_pages; 674 #endif 675 } __randomize_layout; 676 677 /* 678 * The mm_cpumask needs to be at the end of mm_struct, because it 679 * is dynamically sized based on nr_cpu_ids. 680 */ 681 unsigned long cpu_bitmap[]; 682 }; 683 684 extern struct mm_struct init_mm; 685 686 /* Pointer magic because the dynamic array size confuses some compilers. */ 687 static inline void mm_init_cpumask(struct mm_struct *mm) 688 { 689 unsigned long cpu_bitmap = (unsigned long)mm; 690 691 cpu_bitmap += offsetof(struct mm_struct, cpu_bitmap); 692 cpumask_clear((struct cpumask *)cpu_bitmap); 693 } 694 695 /* Future-safe accessor for struct mm_struct's cpu_vm_mask. */ 696 static inline cpumask_t *mm_cpumask(struct mm_struct *mm) 697 { 698 return (struct cpumask *)&mm->cpu_bitmap; 699 } 700 701 struct mmu_gather; 702 extern void tlb_gather_mmu(struct mmu_gather *tlb, struct mm_struct *mm); 703 extern void tlb_gather_mmu_fullmm(struct mmu_gather *tlb, struct mm_struct *mm); 704 extern void tlb_finish_mmu(struct mmu_gather *tlb); 705 706 struct vm_fault; 707 708 /** 709 * typedef vm_fault_t - Return type for page fault handlers. 710 * 711 * Page fault handlers return a bitmask of %VM_FAULT values. 712 */ 713 typedef __bitwise unsigned int vm_fault_t; 714 715 /** 716 * enum vm_fault_reason - Page fault handlers return a bitmask of 717 * these values to tell the core VM what happened when handling the 718 * fault. Used to decide whether a process gets delivered SIGBUS or 719 * just gets major/minor fault counters bumped up. 720 * 721 * @VM_FAULT_OOM: Out Of Memory 722 * @VM_FAULT_SIGBUS: Bad access 723 * @VM_FAULT_MAJOR: Page read from storage 724 * @VM_FAULT_WRITE: Special case for get_user_pages 725 * @VM_FAULT_HWPOISON: Hit poisoned small page 726 * @VM_FAULT_HWPOISON_LARGE: Hit poisoned large page. Index encoded 727 * in upper bits 728 * @VM_FAULT_SIGSEGV: segmentation fault 729 * @VM_FAULT_NOPAGE: ->fault installed the pte, not return page 730 * @VM_FAULT_LOCKED: ->fault locked the returned page 731 * @VM_FAULT_RETRY: ->fault blocked, must retry 732 * @VM_FAULT_FALLBACK: huge page fault failed, fall back to small 733 * @VM_FAULT_DONE_COW: ->fault has fully handled COW 734 * @VM_FAULT_NEEDDSYNC: ->fault did not modify page tables and needs 735 * fsync() to complete (for synchronous page faults 736 * in DAX) 737 * @VM_FAULT_COMPLETED: ->fault completed, meanwhile mmap lock released 738 * @VM_FAULT_HINDEX_MASK: mask HINDEX value 739 * 740 */ 741 enum vm_fault_reason { 742 VM_FAULT_OOM = (__force vm_fault_t)0x000001, 743 VM_FAULT_SIGBUS = (__force vm_fault_t)0x000002, 744 VM_FAULT_MAJOR = (__force vm_fault_t)0x000004, 745 VM_FAULT_WRITE = (__force vm_fault_t)0x000008, 746 VM_FAULT_HWPOISON = (__force vm_fault_t)0x000010, 747 VM_FAULT_HWPOISON_LARGE = (__force vm_fault_t)0x000020, 748 VM_FAULT_SIGSEGV = (__force vm_fault_t)0x000040, 749 VM_FAULT_NOPAGE = (__force vm_fault_t)0x000100, 750 VM_FAULT_LOCKED = (__force vm_fault_t)0x000200, 751 VM_FAULT_RETRY = (__force vm_fault_t)0x000400, 752 VM_FAULT_FALLBACK = (__force vm_fault_t)0x000800, 753 VM_FAULT_DONE_COW = (__force vm_fault_t)0x001000, 754 VM_FAULT_NEEDDSYNC = (__force vm_fault_t)0x002000, 755 VM_FAULT_COMPLETED = (__force vm_fault_t)0x004000, 756 VM_FAULT_HINDEX_MASK = (__force vm_fault_t)0x0f0000, 757 }; 758 759 /* Encode hstate index for a hwpoisoned large page */ 760 #define VM_FAULT_SET_HINDEX(x) ((__force vm_fault_t)((x) << 16)) 761 #define VM_FAULT_GET_HINDEX(x) (((__force unsigned int)(x) >> 16) & 0xf) 762 763 #define VM_FAULT_ERROR (VM_FAULT_OOM | VM_FAULT_SIGBUS | \ 764 VM_FAULT_SIGSEGV | VM_FAULT_HWPOISON | \ 765 VM_FAULT_HWPOISON_LARGE | VM_FAULT_FALLBACK) 766 767 #define VM_FAULT_RESULT_TRACE \ 768 { VM_FAULT_OOM, "OOM" }, \ 769 { VM_FAULT_SIGBUS, "SIGBUS" }, \ 770 { VM_FAULT_MAJOR, "MAJOR" }, \ 771 { VM_FAULT_WRITE, "WRITE" }, \ 772 { VM_FAULT_HWPOISON, "HWPOISON" }, \ 773 { VM_FAULT_HWPOISON_LARGE, "HWPOISON_LARGE" }, \ 774 { VM_FAULT_SIGSEGV, "SIGSEGV" }, \ 775 { VM_FAULT_NOPAGE, "NOPAGE" }, \ 776 { VM_FAULT_LOCKED, "LOCKED" }, \ 777 { VM_FAULT_RETRY, "RETRY" }, \ 778 { VM_FAULT_FALLBACK, "FALLBACK" }, \ 779 { VM_FAULT_DONE_COW, "DONE_COW" }, \ 780 { VM_FAULT_NEEDDSYNC, "NEEDDSYNC" } 781 782 struct vm_special_mapping { 783 const char *name; /* The name, e.g. "[vdso]". */ 784 785 /* 786 * If .fault is not provided, this points to a 787 * NULL-terminated array of pages that back the special mapping. 788 * 789 * This must not be NULL unless .fault is provided. 790 */ 791 struct page **pages; 792 793 /* 794 * If non-NULL, then this is called to resolve page faults 795 * on the special mapping. If used, .pages is not checked. 796 */ 797 vm_fault_t (*fault)(const struct vm_special_mapping *sm, 798 struct vm_area_struct *vma, 799 struct vm_fault *vmf); 800 801 int (*mremap)(const struct vm_special_mapping *sm, 802 struct vm_area_struct *new_vma); 803 }; 804 805 enum tlb_flush_reason { 806 TLB_FLUSH_ON_TASK_SWITCH, 807 TLB_REMOTE_SHOOTDOWN, 808 TLB_LOCAL_SHOOTDOWN, 809 TLB_LOCAL_MM_SHOOTDOWN, 810 TLB_REMOTE_SEND_IPI, 811 NR_TLB_FLUSH_REASONS, 812 }; 813 814 /* 815 * A swap entry has to fit into a "unsigned long", as the entry is hidden 816 * in the "index" field of the swapper address space. 817 */ 818 typedef struct { 819 unsigned long val; 820 } swp_entry_t; 821 822 /** 823 * enum fault_flag - Fault flag definitions. 824 * @FAULT_FLAG_WRITE: Fault was a write fault. 825 * @FAULT_FLAG_MKWRITE: Fault was mkwrite of existing PTE. 826 * @FAULT_FLAG_ALLOW_RETRY: Allow to retry the fault if blocked. 827 * @FAULT_FLAG_RETRY_NOWAIT: Don't drop mmap_lock and wait when retrying. 828 * @FAULT_FLAG_KILLABLE: The fault task is in SIGKILL killable region. 829 * @FAULT_FLAG_TRIED: The fault has been tried once. 830 * @FAULT_FLAG_USER: The fault originated in userspace. 831 * @FAULT_FLAG_REMOTE: The fault is not for current task/mm. 832 * @FAULT_FLAG_INSTRUCTION: The fault was during an instruction fetch. 833 * @FAULT_FLAG_INTERRUPTIBLE: The fault can be interrupted by non-fatal signals. 834 * @FAULT_FLAG_UNSHARE: The fault is an unsharing request to unshare (and mark 835 * exclusive) a possibly shared anonymous page that is 836 * mapped R/O. 837 * @FAULT_FLAG_ORIG_PTE_VALID: whether the fault has vmf->orig_pte cached. 838 * We should only access orig_pte if this flag set. 839 * 840 * About @FAULT_FLAG_ALLOW_RETRY and @FAULT_FLAG_TRIED: we can specify 841 * whether we would allow page faults to retry by specifying these two 842 * fault flags correctly. Currently there can be three legal combinations: 843 * 844 * (a) ALLOW_RETRY and !TRIED: this means the page fault allows retry, and 845 * this is the first try 846 * 847 * (b) ALLOW_RETRY and TRIED: this means the page fault allows retry, and 848 * we've already tried at least once 849 * 850 * (c) !ALLOW_RETRY and !TRIED: this means the page fault does not allow retry 851 * 852 * The unlisted combination (!ALLOW_RETRY && TRIED) is illegal and should never 853 * be used. Note that page faults can be allowed to retry for multiple times, 854 * in which case we'll have an initial fault with flags (a) then later on 855 * continuous faults with flags (b). We should always try to detect pending 856 * signals before a retry to make sure the continuous page faults can still be 857 * interrupted if necessary. 858 * 859 * The combination FAULT_FLAG_WRITE|FAULT_FLAG_UNSHARE is illegal. 860 * FAULT_FLAG_UNSHARE is ignored and treated like an ordinary read fault when 861 * no existing R/O-mapped anonymous page is encountered. 862 */ 863 enum fault_flag { 864 FAULT_FLAG_WRITE = 1 << 0, 865 FAULT_FLAG_MKWRITE = 1 << 1, 866 FAULT_FLAG_ALLOW_RETRY = 1 << 2, 867 FAULT_FLAG_RETRY_NOWAIT = 1 << 3, 868 FAULT_FLAG_KILLABLE = 1 << 4, 869 FAULT_FLAG_TRIED = 1 << 5, 870 FAULT_FLAG_USER = 1 << 6, 871 FAULT_FLAG_REMOTE = 1 << 7, 872 FAULT_FLAG_INSTRUCTION = 1 << 8, 873 FAULT_FLAG_INTERRUPTIBLE = 1 << 9, 874 FAULT_FLAG_UNSHARE = 1 << 10, 875 FAULT_FLAG_ORIG_PTE_VALID = 1 << 11, 876 }; 877 878 typedef unsigned int __bitwise zap_flags_t; 879 880 #endif /* _LINUX_MM_TYPES_H */ 881