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/list.h> 9 #include <linux/spinlock.h> 10 #include <linux/rbtree.h> 11 #include <linux/rwsem.h> 12 #include <linux/completion.h> 13 #include <linux/cpumask.h> 14 #include <linux/uprobes.h> 15 #include <linux/page-flags-layout.h> 16 #include <linux/workqueue.h> 17 18 #include <asm/mmu.h> 19 20 #ifndef AT_VECTOR_SIZE_ARCH 21 #define AT_VECTOR_SIZE_ARCH 0 22 #endif 23 #define AT_VECTOR_SIZE (2*(AT_VECTOR_SIZE_ARCH + AT_VECTOR_SIZE_BASE + 1)) 24 25 26 struct address_space; 27 struct mem_cgroup; 28 29 /* 30 * Each physical page in the system has a struct page associated with 31 * it to keep track of whatever it is we are using the page for at the 32 * moment. Note that we have no way to track which tasks are using 33 * a page, though if it is a pagecache page, rmap structures can tell us 34 * who is mapping it. 35 * 36 * If you allocate the page using alloc_pages(), you can use some of the 37 * space in struct page for your own purposes. The five words in the main 38 * union are available, except for bit 0 of the first word which must be 39 * kept clear. Many users use this word to store a pointer to an object 40 * which is guaranteed to be aligned. If you use the same storage as 41 * page->mapping, you must restore it to NULL before freeing the page. 42 * 43 * If your page will not be mapped to userspace, you can also use the four 44 * bytes in the mapcount union, but you must call page_mapcount_reset() 45 * before freeing it. 46 * 47 * If you want to use the refcount field, it must be used in such a way 48 * that other CPUs temporarily incrementing and then decrementing the 49 * refcount does not cause problems. On receiving the page from 50 * alloc_pages(), the refcount will be positive. 51 * 52 * If you allocate pages of order > 0, you can use some of the fields 53 * in each subpage, but you may need to restore some of their values 54 * afterwards. 55 * 56 * SLUB uses cmpxchg_double() to atomically update its freelist and 57 * counters. That requires that freelist & counters be adjacent and 58 * double-word aligned. We align all struct pages to double-word 59 * boundaries, and ensure that 'freelist' is aligned within the 60 * struct. 61 */ 62 #ifdef CONFIG_HAVE_ALIGNED_STRUCT_PAGE 63 #define _struct_page_alignment __aligned(2 * sizeof(unsigned long)) 64 #else 65 #define _struct_page_alignment 66 #endif 67 68 struct page { 69 unsigned long flags; /* Atomic flags, some possibly 70 * updated asynchronously */ 71 /* 72 * Five words (20/40 bytes) are available in this union. 73 * WARNING: bit 0 of the first word is used for PageTail(). That 74 * means the other users of this union MUST NOT use the bit to 75 * avoid collision and false-positive PageTail(). 76 */ 77 union { 78 struct { /* Page cache and anonymous pages */ 79 /** 80 * @lru: Pageout list, eg. active_list protected by 81 * pgdat->lru_lock. Sometimes used as a generic list 82 * by the page owner. 83 */ 84 struct list_head lru; 85 /* See page-flags.h for PAGE_MAPPING_FLAGS */ 86 struct address_space *mapping; 87 pgoff_t index; /* Our offset within mapping. */ 88 /** 89 * @private: Mapping-private opaque data. 90 * Usually used for buffer_heads if PagePrivate. 91 * Used for swp_entry_t if PageSwapCache. 92 * Indicates order in the buddy system if PageBuddy. 93 */ 94 unsigned long private; 95 }; 96 struct { /* page_pool used by netstack */ 97 /** 98 * @dma_addr: might require a 64-bit value even on 99 * 32-bit architectures. 100 */ 101 dma_addr_t dma_addr; 102 }; 103 struct { /* slab, slob and slub */ 104 union { 105 struct list_head slab_list; 106 struct { /* Partial pages */ 107 struct page *next; 108 #ifdef CONFIG_64BIT 109 int pages; /* Nr of pages left */ 110 int pobjects; /* Approximate count */ 111 #else 112 short int pages; 113 short int pobjects; 114 #endif 115 }; 116 }; 117 struct kmem_cache *slab_cache; /* not slob */ 118 /* Double-word boundary */ 119 void *freelist; /* first free object */ 120 union { 121 void *s_mem; /* slab: first object */ 122 unsigned long counters; /* SLUB */ 123 struct { /* SLUB */ 124 unsigned inuse:16; 125 unsigned objects:15; 126 unsigned frozen:1; 127 }; 128 }; 129 }; 130 struct { /* Tail pages of compound page */ 131 unsigned long compound_head; /* Bit zero is set */ 132 133 /* First tail page only */ 134 unsigned char compound_dtor; 135 unsigned char compound_order; 136 atomic_t compound_mapcount; 137 }; 138 struct { /* Second tail page of compound page */ 139 unsigned long _compound_pad_1; /* compound_head */ 140 unsigned long _compound_pad_2; 141 /* For both global and memcg */ 142 struct list_head deferred_list; 143 }; 144 struct { /* Page table pages */ 145 unsigned long _pt_pad_1; /* compound_head */ 146 pgtable_t pmd_huge_pte; /* protected by page->ptl */ 147 unsigned long _pt_pad_2; /* mapping */ 148 union { 149 struct mm_struct *pt_mm; /* x86 pgds only */ 150 atomic_t pt_frag_refcount; /* powerpc */ 151 }; 152 #if ALLOC_SPLIT_PTLOCKS 153 spinlock_t *ptl; 154 #else 155 spinlock_t ptl; 156 #endif 157 }; 158 struct { /* ZONE_DEVICE pages */ 159 /** @pgmap: Points to the hosting device page map. */ 160 struct dev_pagemap *pgmap; 161 void *zone_device_data; 162 /* 163 * ZONE_DEVICE private pages are counted as being 164 * mapped so the next 3 words hold the mapping, index, 165 * and private fields from the source anonymous or 166 * page cache page while the page is migrated to device 167 * private memory. 168 * ZONE_DEVICE MEMORY_DEVICE_FS_DAX pages also 169 * use the mapping, index, and private fields when 170 * pmem backed DAX files are mapped. 171 */ 172 }; 173 174 /** @rcu_head: You can use this to free a page by RCU. */ 175 struct rcu_head rcu_head; 176 }; 177 178 union { /* This union is 4 bytes in size. */ 179 /* 180 * If the page can be mapped to userspace, encodes the number 181 * of times this page is referenced by a page table. 182 */ 183 atomic_t _mapcount; 184 185 /* 186 * If the page is neither PageSlab nor mappable to userspace, 187 * the value stored here may help determine what this page 188 * is used for. See page-flags.h for a list of page types 189 * which are currently stored here. 190 */ 191 unsigned int page_type; 192 193 unsigned int active; /* SLAB */ 194 int units; /* SLOB */ 195 }; 196 197 /* Usage count. *DO NOT USE DIRECTLY*. See page_ref.h */ 198 atomic_t _refcount; 199 200 #ifdef CONFIG_MEMCG 201 struct mem_cgroup *mem_cgroup; 202 #endif 203 204 /* 205 * On machines where all RAM is mapped into kernel address space, 206 * we can simply calculate the virtual address. On machines with 207 * highmem some memory is mapped into kernel virtual memory 208 * dynamically, so we need a place to store that address. 209 * Note that this field could be 16 bits on x86 ... ;) 210 * 211 * Architectures with slow multiplication can define 212 * WANT_PAGE_VIRTUAL in asm/page.h 213 */ 214 #if defined(WANT_PAGE_VIRTUAL) 215 void *virtual; /* Kernel virtual address (NULL if 216 not kmapped, ie. highmem) */ 217 #endif /* WANT_PAGE_VIRTUAL */ 218 219 #ifdef LAST_CPUPID_NOT_IN_PAGE_FLAGS 220 int _last_cpupid; 221 #endif 222 } _struct_page_alignment; 223 224 static inline atomic_t *compound_mapcount_ptr(struct page *page) 225 { 226 return &page[1].compound_mapcount; 227 } 228 229 /* 230 * Used for sizing the vmemmap region on some architectures 231 */ 232 #define STRUCT_PAGE_MAX_SHIFT (order_base_2(sizeof(struct page))) 233 234 #define PAGE_FRAG_CACHE_MAX_SIZE __ALIGN_MASK(32768, ~PAGE_MASK) 235 #define PAGE_FRAG_CACHE_MAX_ORDER get_order(PAGE_FRAG_CACHE_MAX_SIZE) 236 237 #define page_private(page) ((page)->private) 238 #define set_page_private(page, v) ((page)->private = (v)) 239 240 struct page_frag_cache { 241 void * va; 242 #if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE) 243 __u16 offset; 244 __u16 size; 245 #else 246 __u32 offset; 247 #endif 248 /* we maintain a pagecount bias, so that we dont dirty cache line 249 * containing page->_refcount every time we allocate a fragment. 250 */ 251 unsigned int pagecnt_bias; 252 bool pfmemalloc; 253 }; 254 255 typedef unsigned long vm_flags_t; 256 257 /* 258 * A region containing a mapping of a non-memory backed file under NOMMU 259 * conditions. These are held in a global tree and are pinned by the VMAs that 260 * map parts of them. 261 */ 262 struct vm_region { 263 struct rb_node vm_rb; /* link in global region tree */ 264 vm_flags_t vm_flags; /* VMA vm_flags */ 265 unsigned long vm_start; /* start address of region */ 266 unsigned long vm_end; /* region initialised to here */ 267 unsigned long vm_top; /* region allocated to here */ 268 unsigned long vm_pgoff; /* the offset in vm_file corresponding to vm_start */ 269 struct file *vm_file; /* the backing file or NULL */ 270 271 int vm_usage; /* region usage count (access under nommu_region_sem) */ 272 bool vm_icache_flushed : 1; /* true if the icache has been flushed for 273 * this region */ 274 }; 275 276 #ifdef CONFIG_USERFAULTFD 277 #define NULL_VM_UFFD_CTX ((struct vm_userfaultfd_ctx) { NULL, }) 278 struct vm_userfaultfd_ctx { 279 struct userfaultfd_ctx *ctx; 280 }; 281 #else /* CONFIG_USERFAULTFD */ 282 #define NULL_VM_UFFD_CTX ((struct vm_userfaultfd_ctx) {}) 283 struct vm_userfaultfd_ctx {}; 284 #endif /* CONFIG_USERFAULTFD */ 285 286 /* 287 * This struct defines a memory VMM memory area. There is one of these 288 * per VM-area/task. A VM area is any part of the process virtual memory 289 * space that has a special rule for the page-fault handlers (ie a shared 290 * library, the executable area etc). 291 */ 292 struct vm_area_struct { 293 /* The first cache line has the info for VMA tree walking. */ 294 295 unsigned long vm_start; /* Our start address within vm_mm. */ 296 unsigned long vm_end; /* The first byte after our end address 297 within vm_mm. */ 298 299 /* linked list of VM areas per task, sorted by address */ 300 struct vm_area_struct *vm_next, *vm_prev; 301 302 struct rb_node vm_rb; 303 304 /* 305 * Largest free memory gap in bytes to the left of this VMA. 306 * Either between this VMA and vma->vm_prev, or between one of the 307 * VMAs below us in the VMA rbtree and its ->vm_prev. This helps 308 * get_unmapped_area find a free area of the right size. 309 */ 310 unsigned long rb_subtree_gap; 311 312 /* Second cache line starts here. */ 313 314 struct mm_struct *vm_mm; /* The address space we belong to. */ 315 pgprot_t vm_page_prot; /* Access permissions of this VMA. */ 316 unsigned long vm_flags; /* Flags, see mm.h. */ 317 318 /* 319 * For areas with an address space and backing store, 320 * linkage into the address_space->i_mmap interval tree. 321 */ 322 struct { 323 struct rb_node rb; 324 unsigned long rb_subtree_last; 325 } shared; 326 327 /* 328 * A file's MAP_PRIVATE vma can be in both i_mmap tree and anon_vma 329 * list, after a COW of one of the file pages. A MAP_SHARED vma 330 * can only be in the i_mmap tree. An anonymous MAP_PRIVATE, stack 331 * or brk vma (with NULL file) can only be in an anon_vma list. 332 */ 333 struct list_head anon_vma_chain; /* Serialized by mmap_sem & 334 * page_table_lock */ 335 struct anon_vma *anon_vma; /* Serialized by page_table_lock */ 336 337 /* Function pointers to deal with this struct. */ 338 const struct vm_operations_struct *vm_ops; 339 340 /* Information about our backing store: */ 341 unsigned long vm_pgoff; /* Offset (within vm_file) in PAGE_SIZE 342 units */ 343 struct file * vm_file; /* File we map to (can be NULL). */ 344 void * vm_private_data; /* was vm_pte (shared mem) */ 345 346 #ifdef CONFIG_SWAP 347 atomic_long_t swap_readahead_info; 348 #endif 349 #ifndef CONFIG_MMU 350 struct vm_region *vm_region; /* NOMMU mapping region */ 351 #endif 352 #ifdef CONFIG_NUMA 353 struct mempolicy *vm_policy; /* NUMA policy for the VMA */ 354 #endif 355 struct vm_userfaultfd_ctx vm_userfaultfd_ctx; 356 } __randomize_layout; 357 358 struct core_thread { 359 struct task_struct *task; 360 struct core_thread *next; 361 }; 362 363 struct core_state { 364 atomic_t nr_threads; 365 struct core_thread dumper; 366 struct completion startup; 367 }; 368 369 struct kioctx_table; 370 struct mm_struct { 371 struct { 372 struct vm_area_struct *mmap; /* list of VMAs */ 373 struct rb_root mm_rb; 374 u64 vmacache_seqnum; /* per-thread vmacache */ 375 #ifdef CONFIG_MMU 376 unsigned long (*get_unmapped_area) (struct file *filp, 377 unsigned long addr, unsigned long len, 378 unsigned long pgoff, unsigned long flags); 379 #endif 380 unsigned long mmap_base; /* base of mmap area */ 381 unsigned long mmap_legacy_base; /* base of mmap area in bottom-up allocations */ 382 #ifdef CONFIG_HAVE_ARCH_COMPAT_MMAP_BASES 383 /* Base adresses for compatible mmap() */ 384 unsigned long mmap_compat_base; 385 unsigned long mmap_compat_legacy_base; 386 #endif 387 unsigned long task_size; /* size of task vm space */ 388 unsigned long highest_vm_end; /* highest vma end address */ 389 pgd_t * pgd; 390 391 #ifdef CONFIG_MEMBARRIER 392 /** 393 * @membarrier_state: Flags controlling membarrier behavior. 394 * 395 * This field is close to @pgd to hopefully fit in the same 396 * cache-line, which needs to be touched by switch_mm(). 397 */ 398 atomic_t membarrier_state; 399 #endif 400 401 /** 402 * @mm_users: The number of users including userspace. 403 * 404 * Use mmget()/mmget_not_zero()/mmput() to modify. When this 405 * drops to 0 (i.e. when the task exits and there are no other 406 * temporary reference holders), we also release a reference on 407 * @mm_count (which may then free the &struct mm_struct if 408 * @mm_count also drops to 0). 409 */ 410 atomic_t mm_users; 411 412 /** 413 * @mm_count: The number of references to &struct mm_struct 414 * (@mm_users count as 1). 415 * 416 * Use mmgrab()/mmdrop() to modify. When this drops to 0, the 417 * &struct mm_struct is freed. 418 */ 419 atomic_t mm_count; 420 421 #ifdef CONFIG_MMU 422 atomic_long_t pgtables_bytes; /* PTE page table pages */ 423 #endif 424 int map_count; /* number of VMAs */ 425 426 spinlock_t page_table_lock; /* Protects page tables and some 427 * counters 428 */ 429 struct rw_semaphore mmap_sem; 430 431 struct list_head mmlist; /* List of maybe swapped mm's. These 432 * are globally strung together off 433 * init_mm.mmlist, and are protected 434 * by mmlist_lock 435 */ 436 437 438 unsigned long hiwater_rss; /* High-watermark of RSS usage */ 439 unsigned long hiwater_vm; /* High-water virtual memory usage */ 440 441 unsigned long total_vm; /* Total pages mapped */ 442 unsigned long locked_vm; /* Pages that have PG_mlocked set */ 443 atomic64_t pinned_vm; /* Refcount permanently increased */ 444 unsigned long data_vm; /* VM_WRITE & ~VM_SHARED & ~VM_STACK */ 445 unsigned long exec_vm; /* VM_EXEC & ~VM_WRITE & ~VM_STACK */ 446 unsigned long stack_vm; /* VM_STACK */ 447 unsigned long def_flags; 448 449 spinlock_t arg_lock; /* protect the below fields */ 450 unsigned long start_code, end_code, start_data, end_data; 451 unsigned long start_brk, brk, start_stack; 452 unsigned long arg_start, arg_end, env_start, env_end; 453 454 unsigned long saved_auxv[AT_VECTOR_SIZE]; /* for /proc/PID/auxv */ 455 456 /* 457 * Special counters, in some configurations protected by the 458 * page_table_lock, in other configurations by being atomic. 459 */ 460 struct mm_rss_stat rss_stat; 461 462 struct linux_binfmt *binfmt; 463 464 /* Architecture-specific MM context */ 465 mm_context_t context; 466 467 unsigned long flags; /* Must use atomic bitops to access */ 468 469 struct core_state *core_state; /* coredumping support */ 470 471 #ifdef CONFIG_AIO 472 spinlock_t ioctx_lock; 473 struct kioctx_table __rcu *ioctx_table; 474 #endif 475 #ifdef CONFIG_MEMCG 476 /* 477 * "owner" points to a task that is regarded as the canonical 478 * user/owner of this mm. All of the following must be true in 479 * order for it to be changed: 480 * 481 * current == mm->owner 482 * current->mm != mm 483 * new_owner->mm == mm 484 * new_owner->alloc_lock is held 485 */ 486 struct task_struct __rcu *owner; 487 #endif 488 struct user_namespace *user_ns; 489 490 /* store ref to file /proc/<pid>/exe symlink points to */ 491 struct file __rcu *exe_file; 492 #ifdef CONFIG_MMU_NOTIFIER 493 struct mmu_notifier_mm *mmu_notifier_mm; 494 #endif 495 #if defined(CONFIG_TRANSPARENT_HUGEPAGE) && !USE_SPLIT_PMD_PTLOCKS 496 pgtable_t pmd_huge_pte; /* protected by page_table_lock */ 497 #endif 498 #ifdef CONFIG_NUMA_BALANCING 499 /* 500 * numa_next_scan is the next time that the PTEs will be marked 501 * pte_numa. NUMA hinting faults will gather statistics and 502 * migrate pages to new nodes if necessary. 503 */ 504 unsigned long numa_next_scan; 505 506 /* Restart point for scanning and setting pte_numa */ 507 unsigned long numa_scan_offset; 508 509 /* numa_scan_seq prevents two threads setting pte_numa */ 510 int numa_scan_seq; 511 #endif 512 /* 513 * An operation with batched TLB flushing is going on. Anything 514 * that can move process memory needs to flush the TLB when 515 * moving a PROT_NONE or PROT_NUMA mapped page. 516 */ 517 atomic_t tlb_flush_pending; 518 #ifdef CONFIG_ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH 519 /* See flush_tlb_batched_pending() */ 520 bool tlb_flush_batched; 521 #endif 522 struct uprobes_state uprobes_state; 523 #ifdef CONFIG_HUGETLB_PAGE 524 atomic_long_t hugetlb_usage; 525 #endif 526 struct work_struct async_put_work; 527 } __randomize_layout; 528 529 /* 530 * The mm_cpumask needs to be at the end of mm_struct, because it 531 * is dynamically sized based on nr_cpu_ids. 532 */ 533 unsigned long cpu_bitmap[]; 534 }; 535 536 extern struct mm_struct init_mm; 537 538 /* Pointer magic because the dynamic array size confuses some compilers. */ 539 static inline void mm_init_cpumask(struct mm_struct *mm) 540 { 541 unsigned long cpu_bitmap = (unsigned long)mm; 542 543 cpu_bitmap += offsetof(struct mm_struct, cpu_bitmap); 544 cpumask_clear((struct cpumask *)cpu_bitmap); 545 } 546 547 /* Future-safe accessor for struct mm_struct's cpu_vm_mask. */ 548 static inline cpumask_t *mm_cpumask(struct mm_struct *mm) 549 { 550 return (struct cpumask *)&mm->cpu_bitmap; 551 } 552 553 struct mmu_gather; 554 extern void tlb_gather_mmu(struct mmu_gather *tlb, struct mm_struct *mm, 555 unsigned long start, unsigned long end); 556 extern void tlb_finish_mmu(struct mmu_gather *tlb, 557 unsigned long start, unsigned long end); 558 559 static inline void init_tlb_flush_pending(struct mm_struct *mm) 560 { 561 atomic_set(&mm->tlb_flush_pending, 0); 562 } 563 564 static inline void inc_tlb_flush_pending(struct mm_struct *mm) 565 { 566 atomic_inc(&mm->tlb_flush_pending); 567 /* 568 * The only time this value is relevant is when there are indeed pages 569 * to flush. And we'll only flush pages after changing them, which 570 * requires the PTL. 571 * 572 * So the ordering here is: 573 * 574 * atomic_inc(&mm->tlb_flush_pending); 575 * spin_lock(&ptl); 576 * ... 577 * set_pte_at(); 578 * spin_unlock(&ptl); 579 * 580 * spin_lock(&ptl) 581 * mm_tlb_flush_pending(); 582 * .... 583 * spin_unlock(&ptl); 584 * 585 * flush_tlb_range(); 586 * atomic_dec(&mm->tlb_flush_pending); 587 * 588 * Where the increment if constrained by the PTL unlock, it thus 589 * ensures that the increment is visible if the PTE modification is 590 * visible. After all, if there is no PTE modification, nobody cares 591 * about TLB flushes either. 592 * 593 * This very much relies on users (mm_tlb_flush_pending() and 594 * mm_tlb_flush_nested()) only caring about _specific_ PTEs (and 595 * therefore specific PTLs), because with SPLIT_PTE_PTLOCKS and RCpc 596 * locks (PPC) the unlock of one doesn't order against the lock of 597 * another PTL. 598 * 599 * The decrement is ordered by the flush_tlb_range(), such that 600 * mm_tlb_flush_pending() will not return false unless all flushes have 601 * completed. 602 */ 603 } 604 605 static inline void dec_tlb_flush_pending(struct mm_struct *mm) 606 { 607 /* 608 * See inc_tlb_flush_pending(). 609 * 610 * This cannot be smp_mb__before_atomic() because smp_mb() simply does 611 * not order against TLB invalidate completion, which is what we need. 612 * 613 * Therefore we must rely on tlb_flush_*() to guarantee order. 614 */ 615 atomic_dec(&mm->tlb_flush_pending); 616 } 617 618 static inline bool mm_tlb_flush_pending(struct mm_struct *mm) 619 { 620 /* 621 * Must be called after having acquired the PTL; orders against that 622 * PTLs release and therefore ensures that if we observe the modified 623 * PTE we must also observe the increment from inc_tlb_flush_pending(). 624 * 625 * That is, it only guarantees to return true if there is a flush 626 * pending for _this_ PTL. 627 */ 628 return atomic_read(&mm->tlb_flush_pending); 629 } 630 631 static inline bool mm_tlb_flush_nested(struct mm_struct *mm) 632 { 633 /* 634 * Similar to mm_tlb_flush_pending(), we must have acquired the PTL 635 * for which there is a TLB flush pending in order to guarantee 636 * we've seen both that PTE modification and the increment. 637 * 638 * (no requirement on actually still holding the PTL, that is irrelevant) 639 */ 640 return atomic_read(&mm->tlb_flush_pending) > 1; 641 } 642 643 struct vm_fault; 644 645 /** 646 * typedef vm_fault_t - Return type for page fault handlers. 647 * 648 * Page fault handlers return a bitmask of %VM_FAULT values. 649 */ 650 typedef __bitwise unsigned int vm_fault_t; 651 652 /** 653 * enum vm_fault_reason - Page fault handlers return a bitmask of 654 * these values to tell the core VM what happened when handling the 655 * fault. Used to decide whether a process gets delivered SIGBUS or 656 * just gets major/minor fault counters bumped up. 657 * 658 * @VM_FAULT_OOM: Out Of Memory 659 * @VM_FAULT_SIGBUS: Bad access 660 * @VM_FAULT_MAJOR: Page read from storage 661 * @VM_FAULT_WRITE: Special case for get_user_pages 662 * @VM_FAULT_HWPOISON: Hit poisoned small page 663 * @VM_FAULT_HWPOISON_LARGE: Hit poisoned large page. Index encoded 664 * in upper bits 665 * @VM_FAULT_SIGSEGV: segmentation fault 666 * @VM_FAULT_NOPAGE: ->fault installed the pte, not return page 667 * @VM_FAULT_LOCKED: ->fault locked the returned page 668 * @VM_FAULT_RETRY: ->fault blocked, must retry 669 * @VM_FAULT_FALLBACK: huge page fault failed, fall back to small 670 * @VM_FAULT_DONE_COW: ->fault has fully handled COW 671 * @VM_FAULT_NEEDDSYNC: ->fault did not modify page tables and needs 672 * fsync() to complete (for synchronous page faults 673 * in DAX) 674 * @VM_FAULT_HINDEX_MASK: mask HINDEX value 675 * 676 */ 677 enum vm_fault_reason { 678 VM_FAULT_OOM = (__force vm_fault_t)0x000001, 679 VM_FAULT_SIGBUS = (__force vm_fault_t)0x000002, 680 VM_FAULT_MAJOR = (__force vm_fault_t)0x000004, 681 VM_FAULT_WRITE = (__force vm_fault_t)0x000008, 682 VM_FAULT_HWPOISON = (__force vm_fault_t)0x000010, 683 VM_FAULT_HWPOISON_LARGE = (__force vm_fault_t)0x000020, 684 VM_FAULT_SIGSEGV = (__force vm_fault_t)0x000040, 685 VM_FAULT_NOPAGE = (__force vm_fault_t)0x000100, 686 VM_FAULT_LOCKED = (__force vm_fault_t)0x000200, 687 VM_FAULT_RETRY = (__force vm_fault_t)0x000400, 688 VM_FAULT_FALLBACK = (__force vm_fault_t)0x000800, 689 VM_FAULT_DONE_COW = (__force vm_fault_t)0x001000, 690 VM_FAULT_NEEDDSYNC = (__force vm_fault_t)0x002000, 691 VM_FAULT_HINDEX_MASK = (__force vm_fault_t)0x0f0000, 692 }; 693 694 /* Encode hstate index for a hwpoisoned large page */ 695 #define VM_FAULT_SET_HINDEX(x) ((__force vm_fault_t)((x) << 16)) 696 #define VM_FAULT_GET_HINDEX(x) (((__force unsigned int)(x) >> 16) & 0xf) 697 698 #define VM_FAULT_ERROR (VM_FAULT_OOM | VM_FAULT_SIGBUS | \ 699 VM_FAULT_SIGSEGV | VM_FAULT_HWPOISON | \ 700 VM_FAULT_HWPOISON_LARGE | VM_FAULT_FALLBACK) 701 702 #define VM_FAULT_RESULT_TRACE \ 703 { VM_FAULT_OOM, "OOM" }, \ 704 { VM_FAULT_SIGBUS, "SIGBUS" }, \ 705 { VM_FAULT_MAJOR, "MAJOR" }, \ 706 { VM_FAULT_WRITE, "WRITE" }, \ 707 { VM_FAULT_HWPOISON, "HWPOISON" }, \ 708 { VM_FAULT_HWPOISON_LARGE, "HWPOISON_LARGE" }, \ 709 { VM_FAULT_SIGSEGV, "SIGSEGV" }, \ 710 { VM_FAULT_NOPAGE, "NOPAGE" }, \ 711 { VM_FAULT_LOCKED, "LOCKED" }, \ 712 { VM_FAULT_RETRY, "RETRY" }, \ 713 { VM_FAULT_FALLBACK, "FALLBACK" }, \ 714 { VM_FAULT_DONE_COW, "DONE_COW" }, \ 715 { VM_FAULT_NEEDDSYNC, "NEEDDSYNC" } 716 717 struct vm_special_mapping { 718 const char *name; /* The name, e.g. "[vdso]". */ 719 720 /* 721 * If .fault is not provided, this points to a 722 * NULL-terminated array of pages that back the special mapping. 723 * 724 * This must not be NULL unless .fault is provided. 725 */ 726 struct page **pages; 727 728 /* 729 * If non-NULL, then this is called to resolve page faults 730 * on the special mapping. If used, .pages is not checked. 731 */ 732 vm_fault_t (*fault)(const struct vm_special_mapping *sm, 733 struct vm_area_struct *vma, 734 struct vm_fault *vmf); 735 736 int (*mremap)(const struct vm_special_mapping *sm, 737 struct vm_area_struct *new_vma); 738 }; 739 740 enum tlb_flush_reason { 741 TLB_FLUSH_ON_TASK_SWITCH, 742 TLB_REMOTE_SHOOTDOWN, 743 TLB_LOCAL_SHOOTDOWN, 744 TLB_LOCAL_MM_SHOOTDOWN, 745 TLB_REMOTE_SEND_IPI, 746 NR_TLB_FLUSH_REASONS, 747 }; 748 749 /* 750 * A swap entry has to fit into a "unsigned long", as the entry is hidden 751 * in the "index" field of the swapper address space. 752 */ 753 typedef struct { 754 unsigned long val; 755 } swp_entry_t; 756 757 #endif /* _LINUX_MM_TYPES_H */