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 22 #include <asm/mmu.h> 23 24 #ifndef AT_VECTOR_SIZE_ARCH 25 #define AT_VECTOR_SIZE_ARCH 0 26 #endif 27 #define AT_VECTOR_SIZE (2*(AT_VECTOR_SIZE_ARCH + AT_VECTOR_SIZE_BASE + 1)) 28 29 #define INIT_PASID 0 30 31 struct address_space; 32 struct mem_cgroup; 33 34 /* 35 * Each physical page in the system has a struct page associated with 36 * it to keep track of whatever it is we are using the page for at the 37 * moment. Note that we have no way to track which tasks are using 38 * a page, though if it is a pagecache page, rmap structures can tell us 39 * who is mapping it. 40 * 41 * If you allocate the page using alloc_pages(), you can use some of the 42 * space in struct page for your own purposes. The five words in the main 43 * union are available, except for bit 0 of the first word which must be 44 * kept clear. Many users use this word to store a pointer to an object 45 * which is guaranteed to be aligned. If you use the same storage as 46 * page->mapping, you must restore it to NULL before freeing the page. 47 * 48 * If your page will not be mapped to userspace, you can also use the four 49 * bytes in the mapcount union, but you must call page_mapcount_reset() 50 * before freeing it. 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 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 pgoff_t index; /* Our offset within mapping. */ 107 /** 108 * @private: Mapping-private opaque data. 109 * Usually used for buffer_heads if PagePrivate. 110 * Used for swp_entry_t if PageSwapCache. 111 * Indicates order in the buddy system if PageBuddy. 112 */ 113 unsigned long private; 114 }; 115 struct { /* page_pool used by netstack */ 116 /** 117 * @pp_magic: magic value to avoid recycling non 118 * page_pool allocated pages. 119 */ 120 unsigned long pp_magic; 121 struct page_pool *pp; 122 unsigned long _pp_mapping_pad; 123 unsigned long dma_addr; 124 union { 125 /** 126 * dma_addr_upper: might require a 64-bit 127 * value on 32-bit architectures. 128 */ 129 unsigned long dma_addr_upper; 130 /** 131 * For frag page support, not supported in 132 * 32-bit architectures with 64-bit DMA. 133 */ 134 atomic_long_t pp_frag_count; 135 }; 136 }; 137 struct { /* Tail pages of compound page */ 138 unsigned long compound_head; /* Bit zero is set */ 139 140 /* First tail page only */ 141 unsigned char compound_dtor; 142 unsigned char compound_order; 143 atomic_t compound_mapcount; 144 atomic_t compound_pincount; 145 #ifdef CONFIG_64BIT 146 unsigned int compound_nr; /* 1 << compound_order */ 147 #endif 148 }; 149 struct { /* Second tail page of compound page */ 150 unsigned long _compound_pad_1; /* compound_head */ 151 unsigned long _compound_pad_2; 152 /* For both global and memcg */ 153 struct list_head deferred_list; 154 }; 155 struct { /* Page table pages */ 156 unsigned long _pt_pad_1; /* compound_head */ 157 pgtable_t pmd_huge_pte; /* protected by page->ptl */ 158 unsigned long _pt_pad_2; /* mapping */ 159 union { 160 struct mm_struct *pt_mm; /* x86 pgds only */ 161 atomic_t pt_frag_refcount; /* powerpc */ 162 }; 163 #if ALLOC_SPLIT_PTLOCKS 164 spinlock_t *ptl; 165 #else 166 spinlock_t ptl; 167 #endif 168 }; 169 struct { /* ZONE_DEVICE pages */ 170 /** @pgmap: Points to the hosting device page map. */ 171 struct dev_pagemap *pgmap; 172 void *zone_device_data; 173 /* 174 * ZONE_DEVICE private pages are counted as being 175 * mapped so the next 3 words hold the mapping, index, 176 * and private fields from the source anonymous or 177 * page cache page while the page is migrated to device 178 * private memory. 179 * ZONE_DEVICE MEMORY_DEVICE_FS_DAX pages also 180 * use the mapping, index, and private fields when 181 * pmem backed DAX files are mapped. 182 */ 183 }; 184 185 /** @rcu_head: You can use this to free a page by RCU. */ 186 struct rcu_head rcu_head; 187 }; 188 189 union { /* This union is 4 bytes in size. */ 190 /* 191 * If the page can be mapped to userspace, encodes the number 192 * of times this page is referenced by a page table. 193 */ 194 atomic_t _mapcount; 195 196 /* 197 * If the page is neither PageSlab nor mappable to userspace, 198 * the value stored here may help determine what this page 199 * is used for. See page-flags.h for a list of page types 200 * which are currently stored here. 201 */ 202 unsigned int page_type; 203 }; 204 205 /* Usage count. *DO NOT USE DIRECTLY*. See page_ref.h */ 206 atomic_t _refcount; 207 208 #ifdef CONFIG_MEMCG 209 unsigned long memcg_data; 210 #endif 211 212 /* 213 * On machines where all RAM is mapped into kernel address space, 214 * we can simply calculate the virtual address. On machines with 215 * highmem some memory is mapped into kernel virtual memory 216 * dynamically, so we need a place to store that address. 217 * Note that this field could be 16 bits on x86 ... ;) 218 * 219 * Architectures with slow multiplication can define 220 * WANT_PAGE_VIRTUAL in asm/page.h 221 */ 222 #if defined(WANT_PAGE_VIRTUAL) 223 void *virtual; /* Kernel virtual address (NULL if 224 not kmapped, ie. highmem) */ 225 #endif /* WANT_PAGE_VIRTUAL */ 226 227 #ifdef CONFIG_KMSAN 228 /* 229 * KMSAN metadata for this page: 230 * - shadow page: every bit indicates whether the corresponding 231 * bit of the original page is initialized (0) or not (1); 232 * - origin page: every 4 bytes contain an id of the stack trace 233 * where the uninitialized value was created. 234 */ 235 struct page *kmsan_shadow; 236 struct page *kmsan_origin; 237 #endif 238 239 #ifdef LAST_CPUPID_NOT_IN_PAGE_FLAGS 240 int _last_cpupid; 241 #endif 242 } _struct_page_alignment; 243 244 /** 245 * struct folio - Represents a contiguous set of bytes. 246 * @flags: Identical to the page flags. 247 * @lru: Least Recently Used list; tracks how recently this folio was used. 248 * @mlock_count: Number of times this folio has been pinned by mlock(). 249 * @mapping: The file this page belongs to, or refers to the anon_vma for 250 * anonymous memory. 251 * @index: Offset within the file, in units of pages. For anonymous memory, 252 * this is the index from the beginning of the mmap. 253 * @private: Filesystem per-folio data (see folio_attach_private()). 254 * Used for swp_entry_t if folio_test_swapcache(). 255 * @_mapcount: Do not access this member directly. Use folio_mapcount() to 256 * find out how many times this folio is mapped by userspace. 257 * @_refcount: Do not access this member directly. Use folio_ref_count() 258 * to find how many references there are to this folio. 259 * @memcg_data: Memory Control Group data. 260 * @_flags_1: For large folios, additional page flags. 261 * @__head: Points to the folio. Do not use. 262 * @_folio_dtor: Which destructor to use for this folio. 263 * @_folio_order: Do not use directly, call folio_order(). 264 * @_total_mapcount: Do not use directly, call folio_entire_mapcount(). 265 * @_pincount: Do not use directly, call folio_maybe_dma_pinned(). 266 * @_folio_nr_pages: Do not use directly, call folio_nr_pages(). 267 * 268 * A folio is a physically, virtually and logically contiguous set 269 * of bytes. It is a power-of-two in size, and it is aligned to that 270 * same power-of-two. It is at least as large as %PAGE_SIZE. If it is 271 * in the page cache, it is at a file offset which is a multiple of that 272 * power-of-two. It may be mapped into userspace at an address which is 273 * at an arbitrary page offset, but its kernel virtual address is aligned 274 * to its size. 275 */ 276 struct folio { 277 /* private: don't document the anon union */ 278 union { 279 struct { 280 /* public: */ 281 unsigned long flags; 282 union { 283 struct list_head lru; 284 /* private: avoid cluttering the output */ 285 struct { 286 void *__filler; 287 /* public: */ 288 unsigned int mlock_count; 289 /* private: */ 290 }; 291 /* public: */ 292 }; 293 struct address_space *mapping; 294 pgoff_t index; 295 void *private; 296 atomic_t _mapcount; 297 atomic_t _refcount; 298 #ifdef CONFIG_MEMCG 299 unsigned long memcg_data; 300 #endif 301 /* private: the union with struct page is transitional */ 302 }; 303 struct page page; 304 }; 305 unsigned long _flags_1; 306 unsigned long __head; 307 unsigned char _folio_dtor; 308 unsigned char _folio_order; 309 atomic_t _total_mapcount; 310 atomic_t _pincount; 311 #ifdef CONFIG_64BIT 312 unsigned int _folio_nr_pages; 313 #endif 314 }; 315 316 #define FOLIO_MATCH(pg, fl) \ 317 static_assert(offsetof(struct page, pg) == offsetof(struct folio, fl)) 318 FOLIO_MATCH(flags, flags); 319 FOLIO_MATCH(lru, lru); 320 FOLIO_MATCH(mapping, mapping); 321 FOLIO_MATCH(compound_head, lru); 322 FOLIO_MATCH(index, index); 323 FOLIO_MATCH(private, private); 324 FOLIO_MATCH(_mapcount, _mapcount); 325 FOLIO_MATCH(_refcount, _refcount); 326 #ifdef CONFIG_MEMCG 327 FOLIO_MATCH(memcg_data, memcg_data); 328 #endif 329 #undef FOLIO_MATCH 330 #define FOLIO_MATCH(pg, fl) \ 331 static_assert(offsetof(struct folio, fl) == \ 332 offsetof(struct page, pg) + sizeof(struct page)) 333 FOLIO_MATCH(flags, _flags_1); 334 FOLIO_MATCH(compound_head, __head); 335 FOLIO_MATCH(compound_dtor, _folio_dtor); 336 FOLIO_MATCH(compound_order, _folio_order); 337 FOLIO_MATCH(compound_mapcount, _total_mapcount); 338 FOLIO_MATCH(compound_pincount, _pincount); 339 #ifdef CONFIG_64BIT 340 FOLIO_MATCH(compound_nr, _folio_nr_pages); 341 #endif 342 #undef FOLIO_MATCH 343 344 static inline atomic_t *folio_mapcount_ptr(struct folio *folio) 345 { 346 struct page *tail = &folio->page + 1; 347 return &tail->compound_mapcount; 348 } 349 350 static inline atomic_t *compound_mapcount_ptr(struct page *page) 351 { 352 return &page[1].compound_mapcount; 353 } 354 355 static inline atomic_t *compound_pincount_ptr(struct page *page) 356 { 357 return &page[1].compound_pincount; 358 } 359 360 /* 361 * Used for sizing the vmemmap region on some architectures 362 */ 363 #define STRUCT_PAGE_MAX_SHIFT (order_base_2(sizeof(struct page))) 364 365 #define PAGE_FRAG_CACHE_MAX_SIZE __ALIGN_MASK(32768, ~PAGE_MASK) 366 #define PAGE_FRAG_CACHE_MAX_ORDER get_order(PAGE_FRAG_CACHE_MAX_SIZE) 367 368 /* 369 * page_private can be used on tail pages. However, PagePrivate is only 370 * checked by the VM on the head page. So page_private on the tail pages 371 * should be used for data that's ancillary to the head page (eg attaching 372 * buffer heads to tail pages after attaching buffer heads to the head page) 373 */ 374 #define page_private(page) ((page)->private) 375 376 static inline void set_page_private(struct page *page, unsigned long private) 377 { 378 page->private = private; 379 } 380 381 static inline void *folio_get_private(struct folio *folio) 382 { 383 return folio->private; 384 } 385 386 struct page_frag_cache { 387 void * va; 388 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE) 389 __u16 offset; 390 __u16 size; 391 #else 392 __u32 offset; 393 #endif 394 /* we maintain a pagecount bias, so that we dont dirty cache line 395 * containing page->_refcount every time we allocate a fragment. 396 */ 397 unsigned int pagecnt_bias; 398 bool pfmemalloc; 399 }; 400 401 typedef unsigned long vm_flags_t; 402 403 /* 404 * A region containing a mapping of a non-memory backed file under NOMMU 405 * conditions. These are held in a global tree and are pinned by the VMAs that 406 * map parts of them. 407 */ 408 struct vm_region { 409 struct rb_node vm_rb; /* link in global region tree */ 410 vm_flags_t vm_flags; /* VMA vm_flags */ 411 unsigned long vm_start; /* start address of region */ 412 unsigned long vm_end; /* region initialised to here */ 413 unsigned long vm_top; /* region allocated to here */ 414 unsigned long vm_pgoff; /* the offset in vm_file corresponding to vm_start */ 415 struct file *vm_file; /* the backing file or NULL */ 416 417 int vm_usage; /* region usage count (access under nommu_region_sem) */ 418 bool vm_icache_flushed : 1; /* true if the icache has been flushed for 419 * this region */ 420 }; 421 422 #ifdef CONFIG_USERFAULTFD 423 #define NULL_VM_UFFD_CTX ((struct vm_userfaultfd_ctx) { NULL, }) 424 struct vm_userfaultfd_ctx { 425 struct userfaultfd_ctx *ctx; 426 }; 427 #else /* CONFIG_USERFAULTFD */ 428 #define NULL_VM_UFFD_CTX ((struct vm_userfaultfd_ctx) {}) 429 struct vm_userfaultfd_ctx {}; 430 #endif /* CONFIG_USERFAULTFD */ 431 432 struct anon_vma_name { 433 struct kref kref; 434 /* The name needs to be at the end because it is dynamically sized. */ 435 char name[]; 436 }; 437 438 /* 439 * This struct describes a virtual memory area. There is one of these 440 * per VM-area/task. A VM area is any part of the process virtual memory 441 * space that has a special rule for the page-fault handlers (ie a shared 442 * library, the executable area etc). 443 */ 444 struct vm_area_struct { 445 /* The first cache line has the info for VMA tree walking. */ 446 447 unsigned long vm_start; /* Our start address within vm_mm. */ 448 unsigned long vm_end; /* The first byte after our end address 449 within vm_mm. */ 450 451 struct mm_struct *vm_mm; /* The address space we belong to. */ 452 453 /* 454 * Access permissions of this VMA. 455 * See vmf_insert_mixed_prot() for discussion. 456 */ 457 pgprot_t vm_page_prot; 458 unsigned long vm_flags; /* Flags, see mm.h. */ 459 460 /* 461 * For areas with an address space and backing store, 462 * linkage into the address_space->i_mmap interval tree. 463 * 464 * For private anonymous mappings, a pointer to a null terminated string 465 * containing the name given to the vma, or NULL if unnamed. 466 */ 467 468 union { 469 struct { 470 struct rb_node rb; 471 unsigned long rb_subtree_last; 472 } shared; 473 /* 474 * Serialized by mmap_sem. Never use directly because it is 475 * valid only when vm_file is NULL. Use anon_vma_name instead. 476 */ 477 struct anon_vma_name *anon_name; 478 }; 479 480 /* 481 * A file's MAP_PRIVATE vma can be in both i_mmap tree and anon_vma 482 * list, after a COW of one of the file pages. A MAP_SHARED vma 483 * can only be in the i_mmap tree. An anonymous MAP_PRIVATE, stack 484 * or brk vma (with NULL file) can only be in an anon_vma list. 485 */ 486 struct list_head anon_vma_chain; /* Serialized by mmap_lock & 487 * page_table_lock */ 488 struct anon_vma *anon_vma; /* Serialized by page_table_lock */ 489 490 /* Function pointers to deal with this struct. */ 491 const struct vm_operations_struct *vm_ops; 492 493 /* Information about our backing store: */ 494 unsigned long vm_pgoff; /* Offset (within vm_file) in PAGE_SIZE 495 units */ 496 struct file * vm_file; /* File we map to (can be NULL). */ 497 void * vm_private_data; /* was vm_pte (shared mem) */ 498 499 #ifdef CONFIG_SWAP 500 atomic_long_t swap_readahead_info; 501 #endif 502 #ifndef CONFIG_MMU 503 struct vm_region *vm_region; /* NOMMU mapping region */ 504 #endif 505 #ifdef CONFIG_NUMA 506 struct mempolicy *vm_policy; /* NUMA policy for the VMA */ 507 #endif 508 struct vm_userfaultfd_ctx vm_userfaultfd_ctx; 509 } __randomize_layout; 510 511 struct kioctx_table; 512 struct mm_struct { 513 struct { 514 struct maple_tree mm_mt; 515 #ifdef CONFIG_MMU 516 unsigned long (*get_unmapped_area) (struct file *filp, 517 unsigned long addr, unsigned long len, 518 unsigned long pgoff, unsigned long flags); 519 #endif 520 unsigned long mmap_base; /* base of mmap area */ 521 unsigned long mmap_legacy_base; /* base of mmap area in bottom-up allocations */ 522 #ifdef CONFIG_HAVE_ARCH_COMPAT_MMAP_BASES 523 /* Base addresses for compatible mmap() */ 524 unsigned long mmap_compat_base; 525 unsigned long mmap_compat_legacy_base; 526 #endif 527 unsigned long task_size; /* size of task vm space */ 528 pgd_t * pgd; 529 530 #ifdef CONFIG_MEMBARRIER 531 /** 532 * @membarrier_state: Flags controlling membarrier behavior. 533 * 534 * This field is close to @pgd to hopefully fit in the same 535 * cache-line, which needs to be touched by switch_mm(). 536 */ 537 atomic_t membarrier_state; 538 #endif 539 540 /** 541 * @mm_users: The number of users including userspace. 542 * 543 * Use mmget()/mmget_not_zero()/mmput() to modify. When this 544 * drops to 0 (i.e. when the task exits and there are no other 545 * temporary reference holders), we also release a reference on 546 * @mm_count (which may then free the &struct mm_struct if 547 * @mm_count also drops to 0). 548 */ 549 atomic_t mm_users; 550 551 /** 552 * @mm_count: The number of references to &struct mm_struct 553 * (@mm_users count as 1). 554 * 555 * Use mmgrab()/mmdrop() to modify. When this drops to 0, the 556 * &struct mm_struct is freed. 557 */ 558 atomic_t mm_count; 559 560 #ifdef CONFIG_MMU 561 atomic_long_t pgtables_bytes; /* PTE page table pages */ 562 #endif 563 int map_count; /* number of VMAs */ 564 565 spinlock_t page_table_lock; /* Protects page tables and some 566 * counters 567 */ 568 /* 569 * With some kernel config, the current mmap_lock's offset 570 * inside 'mm_struct' is at 0x120, which is very optimal, as 571 * its two hot fields 'count' and 'owner' sit in 2 different 572 * cachelines, and when mmap_lock is highly contended, both 573 * of the 2 fields will be accessed frequently, current layout 574 * will help to reduce cache bouncing. 575 * 576 * So please be careful with adding new fields before 577 * mmap_lock, which can easily push the 2 fields into one 578 * cacheline. 579 */ 580 struct rw_semaphore mmap_lock; 581 582 struct list_head mmlist; /* List of maybe swapped mm's. These 583 * are globally strung together off 584 * init_mm.mmlist, and are protected 585 * by mmlist_lock 586 */ 587 588 589 unsigned long hiwater_rss; /* High-watermark of RSS usage */ 590 unsigned long hiwater_vm; /* High-water virtual memory usage */ 591 592 unsigned long total_vm; /* Total pages mapped */ 593 unsigned long locked_vm; /* Pages that have PG_mlocked set */ 594 atomic64_t pinned_vm; /* Refcount permanently increased */ 595 unsigned long data_vm; /* VM_WRITE & ~VM_SHARED & ~VM_STACK */ 596 unsigned long exec_vm; /* VM_EXEC & ~VM_WRITE & ~VM_STACK */ 597 unsigned long stack_vm; /* VM_STACK */ 598 unsigned long def_flags; 599 600 /** 601 * @write_protect_seq: Locked when any thread is write 602 * protecting pages mapped by this mm to enforce a later COW, 603 * for instance during page table copying for fork(). 604 */ 605 seqcount_t write_protect_seq; 606 607 spinlock_t arg_lock; /* protect the below fields */ 608 609 unsigned long start_code, end_code, start_data, end_data; 610 unsigned long start_brk, brk, start_stack; 611 unsigned long arg_start, arg_end, env_start, env_end; 612 613 unsigned long saved_auxv[AT_VECTOR_SIZE]; /* for /proc/PID/auxv */ 614 615 /* 616 * Special counters, in some configurations protected by the 617 * page_table_lock, in other configurations by being atomic. 618 */ 619 struct mm_rss_stat rss_stat; 620 621 struct linux_binfmt *binfmt; 622 623 /* Architecture-specific MM context */ 624 mm_context_t context; 625 626 unsigned long flags; /* Must use atomic bitops to access */ 627 628 #ifdef CONFIG_AIO 629 spinlock_t ioctx_lock; 630 struct kioctx_table __rcu *ioctx_table; 631 #endif 632 #ifdef CONFIG_MEMCG 633 /* 634 * "owner" points to a task that is regarded as the canonical 635 * user/owner of this mm. All of the following must be true in 636 * order for it to be changed: 637 * 638 * current == mm->owner 639 * current->mm != mm 640 * new_owner->mm == mm 641 * new_owner->alloc_lock is held 642 */ 643 struct task_struct __rcu *owner; 644 #endif 645 struct user_namespace *user_ns; 646 647 /* store ref to file /proc/<pid>/exe symlink points to */ 648 struct file __rcu *exe_file; 649 #ifdef CONFIG_MMU_NOTIFIER 650 struct mmu_notifier_subscriptions *notifier_subscriptions; 651 #endif 652 #if defined(CONFIG_TRANSPARENT_HUGEPAGE) && !USE_SPLIT_PMD_PTLOCKS 653 pgtable_t pmd_huge_pte; /* protected by page_table_lock */ 654 #endif 655 #ifdef CONFIG_NUMA_BALANCING 656 /* 657 * numa_next_scan is the next time that PTEs will be remapped 658 * PROT_NONE to trigger NUMA hinting faults; such faults gather 659 * statistics and migrate pages to new nodes if necessary. 660 */ 661 unsigned long numa_next_scan; 662 663 /* Restart point for scanning and remapping PTEs. */ 664 unsigned long numa_scan_offset; 665 666 /* numa_scan_seq prevents two threads remapping PTEs. */ 667 int numa_scan_seq; 668 #endif 669 /* 670 * An operation with batched TLB flushing is going on. Anything 671 * that can move process memory needs to flush the TLB when 672 * moving a PROT_NONE mapped page. 673 */ 674 atomic_t tlb_flush_pending; 675 #ifdef CONFIG_ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH 676 /* See flush_tlb_batched_pending() */ 677 atomic_t tlb_flush_batched; 678 #endif 679 struct uprobes_state uprobes_state; 680 #ifdef CONFIG_PREEMPT_RT 681 struct rcu_head delayed_drop; 682 #endif 683 #ifdef CONFIG_HUGETLB_PAGE 684 atomic_long_t hugetlb_usage; 685 #endif 686 struct work_struct async_put_work; 687 688 #ifdef CONFIG_IOMMU_SVA 689 u32 pasid; 690 #endif 691 #ifdef CONFIG_KSM 692 /* 693 * Represent how many pages of this process are involved in KSM 694 * merging. 695 */ 696 unsigned long ksm_merging_pages; 697 /* 698 * Represent how many pages are checked for ksm merging 699 * including merged and not merged. 700 */ 701 unsigned long ksm_rmap_items; 702 #endif 703 #ifdef CONFIG_LRU_GEN 704 struct { 705 /* this mm_struct is on lru_gen_mm_list */ 706 struct list_head list; 707 /* 708 * Set when switching to this mm_struct, as a hint of 709 * whether it has been used since the last time per-node 710 * page table walkers cleared the corresponding bits. 711 */ 712 unsigned long bitmap; 713 #ifdef CONFIG_MEMCG 714 /* points to the memcg of "owner" above */ 715 struct mem_cgroup *memcg; 716 #endif 717 } lru_gen; 718 #endif /* CONFIG_LRU_GEN */ 719 } __randomize_layout; 720 721 /* 722 * The mm_cpumask needs to be at the end of mm_struct, because it 723 * is dynamically sized based on nr_cpu_ids. 724 */ 725 unsigned long cpu_bitmap[]; 726 }; 727 728 #define MM_MT_FLAGS (MT_FLAGS_ALLOC_RANGE | MT_FLAGS_LOCK_EXTERN) 729 extern struct mm_struct init_mm; 730 731 /* Pointer magic because the dynamic array size confuses some compilers. */ 732 static inline void mm_init_cpumask(struct mm_struct *mm) 733 { 734 unsigned long cpu_bitmap = (unsigned long)mm; 735 736 cpu_bitmap += offsetof(struct mm_struct, cpu_bitmap); 737 cpumask_clear((struct cpumask *)cpu_bitmap); 738 } 739 740 /* Future-safe accessor for struct mm_struct's cpu_vm_mask. */ 741 static inline cpumask_t *mm_cpumask(struct mm_struct *mm) 742 { 743 return (struct cpumask *)&mm->cpu_bitmap; 744 } 745 746 #ifdef CONFIG_LRU_GEN 747 748 struct lru_gen_mm_list { 749 /* mm_struct list for page table walkers */ 750 struct list_head fifo; 751 /* protects the list above */ 752 spinlock_t lock; 753 }; 754 755 void lru_gen_add_mm(struct mm_struct *mm); 756 void lru_gen_del_mm(struct mm_struct *mm); 757 #ifdef CONFIG_MEMCG 758 void lru_gen_migrate_mm(struct mm_struct *mm); 759 #endif 760 761 static inline void lru_gen_init_mm(struct mm_struct *mm) 762 { 763 INIT_LIST_HEAD(&mm->lru_gen.list); 764 mm->lru_gen.bitmap = 0; 765 #ifdef CONFIG_MEMCG 766 mm->lru_gen.memcg = NULL; 767 #endif 768 } 769 770 static inline void lru_gen_use_mm(struct mm_struct *mm) 771 { 772 /* 773 * When the bitmap is set, page reclaim knows this mm_struct has been 774 * used since the last time it cleared the bitmap. So it might be worth 775 * walking the page tables of this mm_struct to clear the accessed bit. 776 */ 777 WRITE_ONCE(mm->lru_gen.bitmap, -1); 778 } 779 780 #else /* !CONFIG_LRU_GEN */ 781 782 static inline void lru_gen_add_mm(struct mm_struct *mm) 783 { 784 } 785 786 static inline void lru_gen_del_mm(struct mm_struct *mm) 787 { 788 } 789 790 #ifdef CONFIG_MEMCG 791 static inline void lru_gen_migrate_mm(struct mm_struct *mm) 792 { 793 } 794 #endif 795 796 static inline void lru_gen_init_mm(struct mm_struct *mm) 797 { 798 } 799 800 static inline void lru_gen_use_mm(struct mm_struct *mm) 801 { 802 } 803 804 #endif /* CONFIG_LRU_GEN */ 805 806 struct vma_iterator { 807 struct ma_state mas; 808 }; 809 810 #define VMA_ITERATOR(name, __mm, __addr) \ 811 struct vma_iterator name = { \ 812 .mas = { \ 813 .tree = &(__mm)->mm_mt, \ 814 .index = __addr, \ 815 .node = MAS_START, \ 816 }, \ 817 } 818 819 static inline void vma_iter_init(struct vma_iterator *vmi, 820 struct mm_struct *mm, unsigned long addr) 821 { 822 vmi->mas.tree = &mm->mm_mt; 823 vmi->mas.index = addr; 824 vmi->mas.node = MAS_START; 825 } 826 827 struct mmu_gather; 828 extern void tlb_gather_mmu(struct mmu_gather *tlb, struct mm_struct *mm); 829 extern void tlb_gather_mmu_fullmm(struct mmu_gather *tlb, struct mm_struct *mm); 830 extern void tlb_finish_mmu(struct mmu_gather *tlb); 831 832 struct vm_fault; 833 834 /** 835 * typedef vm_fault_t - Return type for page fault handlers. 836 * 837 * Page fault handlers return a bitmask of %VM_FAULT values. 838 */ 839 typedef __bitwise unsigned int vm_fault_t; 840 841 /** 842 * enum vm_fault_reason - Page fault handlers return a bitmask of 843 * these values to tell the core VM what happened when handling the 844 * fault. Used to decide whether a process gets delivered SIGBUS or 845 * just gets major/minor fault counters bumped up. 846 * 847 * @VM_FAULT_OOM: Out Of Memory 848 * @VM_FAULT_SIGBUS: Bad access 849 * @VM_FAULT_MAJOR: Page read from storage 850 * @VM_FAULT_WRITE: Special case for get_user_pages 851 * @VM_FAULT_HWPOISON: Hit poisoned small page 852 * @VM_FAULT_HWPOISON_LARGE: Hit poisoned large page. Index encoded 853 * in upper bits 854 * @VM_FAULT_SIGSEGV: segmentation fault 855 * @VM_FAULT_NOPAGE: ->fault installed the pte, not return page 856 * @VM_FAULT_LOCKED: ->fault locked the returned page 857 * @VM_FAULT_RETRY: ->fault blocked, must retry 858 * @VM_FAULT_FALLBACK: huge page fault failed, fall back to small 859 * @VM_FAULT_DONE_COW: ->fault has fully handled COW 860 * @VM_FAULT_NEEDDSYNC: ->fault did not modify page tables and needs 861 * fsync() to complete (for synchronous page faults 862 * in DAX) 863 * @VM_FAULT_COMPLETED: ->fault completed, meanwhile mmap lock released 864 * @VM_FAULT_HINDEX_MASK: mask HINDEX value 865 * 866 */ 867 enum vm_fault_reason { 868 VM_FAULT_OOM = (__force vm_fault_t)0x000001, 869 VM_FAULT_SIGBUS = (__force vm_fault_t)0x000002, 870 VM_FAULT_MAJOR = (__force vm_fault_t)0x000004, 871 VM_FAULT_WRITE = (__force vm_fault_t)0x000008, 872 VM_FAULT_HWPOISON = (__force vm_fault_t)0x000010, 873 VM_FAULT_HWPOISON_LARGE = (__force vm_fault_t)0x000020, 874 VM_FAULT_SIGSEGV = (__force vm_fault_t)0x000040, 875 VM_FAULT_NOPAGE = (__force vm_fault_t)0x000100, 876 VM_FAULT_LOCKED = (__force vm_fault_t)0x000200, 877 VM_FAULT_RETRY = (__force vm_fault_t)0x000400, 878 VM_FAULT_FALLBACK = (__force vm_fault_t)0x000800, 879 VM_FAULT_DONE_COW = (__force vm_fault_t)0x001000, 880 VM_FAULT_NEEDDSYNC = (__force vm_fault_t)0x002000, 881 VM_FAULT_COMPLETED = (__force vm_fault_t)0x004000, 882 VM_FAULT_HINDEX_MASK = (__force vm_fault_t)0x0f0000, 883 }; 884 885 /* Encode hstate index for a hwpoisoned large page */ 886 #define VM_FAULT_SET_HINDEX(x) ((__force vm_fault_t)((x) << 16)) 887 #define VM_FAULT_GET_HINDEX(x) (((__force unsigned int)(x) >> 16) & 0xf) 888 889 #define VM_FAULT_ERROR (VM_FAULT_OOM | VM_FAULT_SIGBUS | \ 890 VM_FAULT_SIGSEGV | VM_FAULT_HWPOISON | \ 891 VM_FAULT_HWPOISON_LARGE | VM_FAULT_FALLBACK) 892 893 #define VM_FAULT_RESULT_TRACE \ 894 { VM_FAULT_OOM, "OOM" }, \ 895 { VM_FAULT_SIGBUS, "SIGBUS" }, \ 896 { VM_FAULT_MAJOR, "MAJOR" }, \ 897 { VM_FAULT_WRITE, "WRITE" }, \ 898 { VM_FAULT_HWPOISON, "HWPOISON" }, \ 899 { VM_FAULT_HWPOISON_LARGE, "HWPOISON_LARGE" }, \ 900 { VM_FAULT_SIGSEGV, "SIGSEGV" }, \ 901 { VM_FAULT_NOPAGE, "NOPAGE" }, \ 902 { VM_FAULT_LOCKED, "LOCKED" }, \ 903 { VM_FAULT_RETRY, "RETRY" }, \ 904 { VM_FAULT_FALLBACK, "FALLBACK" }, \ 905 { VM_FAULT_DONE_COW, "DONE_COW" }, \ 906 { VM_FAULT_NEEDDSYNC, "NEEDDSYNC" } 907 908 struct vm_special_mapping { 909 const char *name; /* The name, e.g. "[vdso]". */ 910 911 /* 912 * If .fault is not provided, this points to a 913 * NULL-terminated array of pages that back the special mapping. 914 * 915 * This must not be NULL unless .fault is provided. 916 */ 917 struct page **pages; 918 919 /* 920 * If non-NULL, then this is called to resolve page faults 921 * on the special mapping. If used, .pages is not checked. 922 */ 923 vm_fault_t (*fault)(const struct vm_special_mapping *sm, 924 struct vm_area_struct *vma, 925 struct vm_fault *vmf); 926 927 int (*mremap)(const struct vm_special_mapping *sm, 928 struct vm_area_struct *new_vma); 929 }; 930 931 enum tlb_flush_reason { 932 TLB_FLUSH_ON_TASK_SWITCH, 933 TLB_REMOTE_SHOOTDOWN, 934 TLB_LOCAL_SHOOTDOWN, 935 TLB_LOCAL_MM_SHOOTDOWN, 936 TLB_REMOTE_SEND_IPI, 937 NR_TLB_FLUSH_REASONS, 938 }; 939 940 /* 941 * A swap entry has to fit into a "unsigned long", as the entry is hidden 942 * in the "index" field of the swapper address space. 943 */ 944 typedef struct { 945 unsigned long val; 946 } swp_entry_t; 947 948 /** 949 * enum fault_flag - Fault flag definitions. 950 * @FAULT_FLAG_WRITE: Fault was a write fault. 951 * @FAULT_FLAG_MKWRITE: Fault was mkwrite of existing PTE. 952 * @FAULT_FLAG_ALLOW_RETRY: Allow to retry the fault if blocked. 953 * @FAULT_FLAG_RETRY_NOWAIT: Don't drop mmap_lock and wait when retrying. 954 * @FAULT_FLAG_KILLABLE: The fault task is in SIGKILL killable region. 955 * @FAULT_FLAG_TRIED: The fault has been tried once. 956 * @FAULT_FLAG_USER: The fault originated in userspace. 957 * @FAULT_FLAG_REMOTE: The fault is not for current task/mm. 958 * @FAULT_FLAG_INSTRUCTION: The fault was during an instruction fetch. 959 * @FAULT_FLAG_INTERRUPTIBLE: The fault can be interrupted by non-fatal signals. 960 * @FAULT_FLAG_UNSHARE: The fault is an unsharing request to unshare (and mark 961 * exclusive) a possibly shared anonymous page that is 962 * mapped R/O. 963 * @FAULT_FLAG_ORIG_PTE_VALID: whether the fault has vmf->orig_pte cached. 964 * We should only access orig_pte if this flag set. 965 * 966 * About @FAULT_FLAG_ALLOW_RETRY and @FAULT_FLAG_TRIED: we can specify 967 * whether we would allow page faults to retry by specifying these two 968 * fault flags correctly. Currently there can be three legal combinations: 969 * 970 * (a) ALLOW_RETRY and !TRIED: this means the page fault allows retry, and 971 * this is the first try 972 * 973 * (b) ALLOW_RETRY and TRIED: this means the page fault allows retry, and 974 * we've already tried at least once 975 * 976 * (c) !ALLOW_RETRY and !TRIED: this means the page fault does not allow retry 977 * 978 * The unlisted combination (!ALLOW_RETRY && TRIED) is illegal and should never 979 * be used. Note that page faults can be allowed to retry for multiple times, 980 * in which case we'll have an initial fault with flags (a) then later on 981 * continuous faults with flags (b). We should always try to detect pending 982 * signals before a retry to make sure the continuous page faults can still be 983 * interrupted if necessary. 984 * 985 * The combination FAULT_FLAG_WRITE|FAULT_FLAG_UNSHARE is illegal. 986 * FAULT_FLAG_UNSHARE is ignored and treated like an ordinary read fault when 987 * no existing R/O-mapped anonymous page is encountered. 988 */ 989 enum fault_flag { 990 FAULT_FLAG_WRITE = 1 << 0, 991 FAULT_FLAG_MKWRITE = 1 << 1, 992 FAULT_FLAG_ALLOW_RETRY = 1 << 2, 993 FAULT_FLAG_RETRY_NOWAIT = 1 << 3, 994 FAULT_FLAG_KILLABLE = 1 << 4, 995 FAULT_FLAG_TRIED = 1 << 5, 996 FAULT_FLAG_USER = 1 << 6, 997 FAULT_FLAG_REMOTE = 1 << 7, 998 FAULT_FLAG_INSTRUCTION = 1 << 8, 999 FAULT_FLAG_INTERRUPTIBLE = 1 << 9, 1000 FAULT_FLAG_UNSHARE = 1 << 10, 1001 FAULT_FLAG_ORIG_PTE_VALID = 1 << 11, 1002 }; 1003 1004 typedef unsigned int __bitwise zap_flags_t; 1005 1006 #endif /* _LINUX_MM_TYPES_H */ 1007