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