1 /* SPDX-License-Identifier: GPL-2.0 */
5 #include <linux/errno.h>
6 #include <linux/mmdebug.h>
9 #include <linux/list.h>
10 #include <linux/mmzone.h>
11 #include <linux/rbtree.h>
12 #include <linux/atomic.h>
13 #include <linux/debug_locks.h>
14 #include <linux/mm_types.h>
15 #include <linux/mmap_lock.h>
16 #include <linux/range.h>
17 #include <linux/pfn.h>
18 #include <linux/percpu-refcount.h>
19 #include <linux/bit_spinlock.h>
20 #include <linux/shrinker.h>
21 #include <linux/resource.h>
22 #include <linux/page_ext.h>
23 #include <linux/err.h>
24 #include <linux/page-flags.h>
25 #include <linux/page_ref.h>
26 #include <linux/overflow.h>
27 #include <linux/sizes.h>
28 #include <linux/sched.h>
29 #include <linux/pgtable.h>
30 #include <linux/kasan.h>
31 #include <linux/memremap.h>
35 struct anon_vma_chain;
39 extern int sysctl_page_lock_unfairness;
41 void init_mm_internals(void);
43 #ifndef CONFIG_NUMA /* Don't use mapnrs, do it properly */
44 extern unsigned long max_mapnr;
46 static inline void set_max_mapnr(unsigned long limit)
51 static inline void set_max_mapnr(unsigned long limit) { }
54 extern atomic_long_t _totalram_pages;
55 static inline unsigned long totalram_pages(void)
57 return (unsigned long)atomic_long_read(&_totalram_pages);
60 static inline void totalram_pages_inc(void)
62 atomic_long_inc(&_totalram_pages);
65 static inline void totalram_pages_dec(void)
67 atomic_long_dec(&_totalram_pages);
70 static inline void totalram_pages_add(long count)
72 atomic_long_add(count, &_totalram_pages);
75 extern void * high_memory;
76 extern int page_cluster;
77 extern const int page_cluster_max;
80 extern int sysctl_legacy_va_layout;
82 #define sysctl_legacy_va_layout 0
85 #ifdef CONFIG_HAVE_ARCH_MMAP_RND_BITS
86 extern const int mmap_rnd_bits_min;
87 extern const int mmap_rnd_bits_max;
88 extern int mmap_rnd_bits __read_mostly;
90 #ifdef CONFIG_HAVE_ARCH_MMAP_RND_COMPAT_BITS
91 extern const int mmap_rnd_compat_bits_min;
92 extern const int mmap_rnd_compat_bits_max;
93 extern int mmap_rnd_compat_bits __read_mostly;
97 #include <asm/processor.h>
100 * Architectures that support memory tagging (assigning tags to memory regions,
101 * embedding these tags into addresses that point to these memory regions, and
102 * checking that the memory and the pointer tags match on memory accesses)
103 * redefine this macro to strip tags from pointers.
104 * It's defined as noop for architectures that don't support memory tagging.
106 #ifndef untagged_addr
107 #define untagged_addr(addr) (addr)
111 #define __pa_symbol(x) __pa(RELOC_HIDE((unsigned long)(x), 0))
115 #define page_to_virt(x) __va(PFN_PHYS(page_to_pfn(x)))
119 #define lm_alias(x) __va(__pa_symbol(x))
123 * To prevent common memory management code establishing
124 * a zero page mapping on a read fault.
125 * This macro should be defined within <asm/pgtable.h>.
126 * s390 does this to prevent multiplexing of hardware bits
127 * related to the physical page in case of virtualization.
129 #ifndef mm_forbids_zeropage
130 #define mm_forbids_zeropage(X) (0)
134 * On some architectures it is expensive to call memset() for small sizes.
135 * If an architecture decides to implement their own version of
136 * mm_zero_struct_page they should wrap the defines below in a #ifndef and
137 * define their own version of this macro in <asm/pgtable.h>
139 #if BITS_PER_LONG == 64
140 /* This function must be updated when the size of struct page grows above 80
141 * or reduces below 56. The idea that compiler optimizes out switch()
142 * statement, and only leaves move/store instructions. Also the compiler can
143 * combine write statements if they are both assignments and can be reordered,
144 * this can result in several of the writes here being dropped.
146 #define mm_zero_struct_page(pp) __mm_zero_struct_page(pp)
147 static inline void __mm_zero_struct_page(struct page *page)
149 unsigned long *_pp = (void *)page;
151 /* Check that struct page is either 56, 64, 72, or 80 bytes */
152 BUILD_BUG_ON(sizeof(struct page) & 7);
153 BUILD_BUG_ON(sizeof(struct page) < 56);
154 BUILD_BUG_ON(sizeof(struct page) > 80);
156 switch (sizeof(struct page)) {
177 #define mm_zero_struct_page(pp) ((void)memset((pp), 0, sizeof(struct page)))
181 * Default maximum number of active map areas, this limits the number of vmas
182 * per mm struct. Users can overwrite this number by sysctl but there is a
185 * When a program's coredump is generated as ELF format, a section is created
186 * per a vma. In ELF, the number of sections is represented in unsigned short.
187 * This means the number of sections should be smaller than 65535 at coredump.
188 * Because the kernel adds some informative sections to a image of program at
189 * generating coredump, we need some margin. The number of extra sections is
190 * 1-3 now and depends on arch. We use "5" as safe margin, here.
192 * ELF extended numbering allows more than 65535 sections, so 16-bit bound is
193 * not a hard limit any more. Although some userspace tools can be surprised by
196 #define MAPCOUNT_ELF_CORE_MARGIN (5)
197 #define DEFAULT_MAX_MAP_COUNT (USHRT_MAX - MAPCOUNT_ELF_CORE_MARGIN)
199 extern int sysctl_max_map_count;
201 extern unsigned long sysctl_user_reserve_kbytes;
202 extern unsigned long sysctl_admin_reserve_kbytes;
204 extern int sysctl_overcommit_memory;
205 extern int sysctl_overcommit_ratio;
206 extern unsigned long sysctl_overcommit_kbytes;
208 int overcommit_ratio_handler(struct ctl_table *, int, void *, size_t *,
210 int overcommit_kbytes_handler(struct ctl_table *, int, void *, size_t *,
212 int overcommit_policy_handler(struct ctl_table *, int, void *, size_t *,
215 #if defined(CONFIG_SPARSEMEM) && !defined(CONFIG_SPARSEMEM_VMEMMAP)
216 #define nth_page(page,n) pfn_to_page(page_to_pfn((page)) + (n))
217 #define folio_page_idx(folio, p) (page_to_pfn(p) - folio_pfn(folio))
219 #define nth_page(page,n) ((page) + (n))
220 #define folio_page_idx(folio, p) ((p) - &(folio)->page)
223 /* to align the pointer to the (next) page boundary */
224 #define PAGE_ALIGN(addr) ALIGN(addr, PAGE_SIZE)
226 /* to align the pointer to the (prev) page boundary */
227 #define PAGE_ALIGN_DOWN(addr) ALIGN_DOWN(addr, PAGE_SIZE)
229 /* test whether an address (unsigned long or pointer) is aligned to PAGE_SIZE */
230 #define PAGE_ALIGNED(addr) IS_ALIGNED((unsigned long)(addr), PAGE_SIZE)
232 #define lru_to_page(head) (list_entry((head)->prev, struct page, lru))
233 static inline struct folio *lru_to_folio(struct list_head *head)
235 return list_entry((head)->prev, struct folio, lru);
238 void setup_initial_init_mm(void *start_code, void *end_code,
239 void *end_data, void *brk);
242 * Linux kernel virtual memory manager primitives.
243 * The idea being to have a "virtual" mm in the same way
244 * we have a virtual fs - giving a cleaner interface to the
245 * mm details, and allowing different kinds of memory mappings
246 * (from shared memory to executable loading to arbitrary
250 struct vm_area_struct *vm_area_alloc(struct mm_struct *);
251 struct vm_area_struct *vm_area_dup(struct vm_area_struct *);
252 void vm_area_free(struct vm_area_struct *);
255 extern struct rb_root nommu_region_tree;
256 extern struct rw_semaphore nommu_region_sem;
258 extern unsigned int kobjsize(const void *objp);
262 * vm_flags in vm_area_struct, see mm_types.h.
263 * When changing, update also include/trace/events/mmflags.h
265 #define VM_NONE 0x00000000
267 #define VM_READ 0x00000001 /* currently active flags */
268 #define VM_WRITE 0x00000002
269 #define VM_EXEC 0x00000004
270 #define VM_SHARED 0x00000008
272 /* mprotect() hardcodes VM_MAYREAD >> 4 == VM_READ, and so for r/w/x bits. */
273 #define VM_MAYREAD 0x00000010 /* limits for mprotect() etc */
274 #define VM_MAYWRITE 0x00000020
275 #define VM_MAYEXEC 0x00000040
276 #define VM_MAYSHARE 0x00000080
278 #define VM_GROWSDOWN 0x00000100 /* general info on the segment */
279 #define VM_UFFD_MISSING 0x00000200 /* missing pages tracking */
280 #define VM_PFNMAP 0x00000400 /* Page-ranges managed without "struct page", just pure PFN */
281 #define VM_UFFD_WP 0x00001000 /* wrprotect pages tracking */
283 #define VM_LOCKED 0x00002000
284 #define VM_IO 0x00004000 /* Memory mapped I/O or similar */
286 /* Used by sys_madvise() */
287 #define VM_SEQ_READ 0x00008000 /* App will access data sequentially */
288 #define VM_RAND_READ 0x00010000 /* App will not benefit from clustered reads */
290 #define VM_DONTCOPY 0x00020000 /* Do not copy this vma on fork */
291 #define VM_DONTEXPAND 0x00040000 /* Cannot expand with mremap() */
292 #define VM_LOCKONFAULT 0x00080000 /* Lock the pages covered when they are faulted in */
293 #define VM_ACCOUNT 0x00100000 /* Is a VM accounted object */
294 #define VM_NORESERVE 0x00200000 /* should the VM suppress accounting */
295 #define VM_HUGETLB 0x00400000 /* Huge TLB Page VM */
296 #define VM_SYNC 0x00800000 /* Synchronous page faults */
297 #define VM_ARCH_1 0x01000000 /* Architecture-specific flag */
298 #define VM_WIPEONFORK 0x02000000 /* Wipe VMA contents in child. */
299 #define VM_DONTDUMP 0x04000000 /* Do not include in the core dump */
301 #ifdef CONFIG_MEM_SOFT_DIRTY
302 # define VM_SOFTDIRTY 0x08000000 /* Not soft dirty clean area */
304 # define VM_SOFTDIRTY 0
307 #define VM_MIXEDMAP 0x10000000 /* Can contain "struct page" and pure PFN pages */
308 #define VM_HUGEPAGE 0x20000000 /* MADV_HUGEPAGE marked this vma */
309 #define VM_NOHUGEPAGE 0x40000000 /* MADV_NOHUGEPAGE marked this vma */
310 #define VM_MERGEABLE 0x80000000 /* KSM may merge identical pages */
312 #ifdef CONFIG_ARCH_USES_HIGH_VMA_FLAGS
313 #define VM_HIGH_ARCH_BIT_0 32 /* bit only usable on 64-bit architectures */
314 #define VM_HIGH_ARCH_BIT_1 33 /* bit only usable on 64-bit architectures */
315 #define VM_HIGH_ARCH_BIT_2 34 /* bit only usable on 64-bit architectures */
316 #define VM_HIGH_ARCH_BIT_3 35 /* bit only usable on 64-bit architectures */
317 #define VM_HIGH_ARCH_BIT_4 36 /* bit only usable on 64-bit architectures */
318 #define VM_HIGH_ARCH_0 BIT(VM_HIGH_ARCH_BIT_0)
319 #define VM_HIGH_ARCH_1 BIT(VM_HIGH_ARCH_BIT_1)
320 #define VM_HIGH_ARCH_2 BIT(VM_HIGH_ARCH_BIT_2)
321 #define VM_HIGH_ARCH_3 BIT(VM_HIGH_ARCH_BIT_3)
322 #define VM_HIGH_ARCH_4 BIT(VM_HIGH_ARCH_BIT_4)
323 #endif /* CONFIG_ARCH_USES_HIGH_VMA_FLAGS */
325 #ifdef CONFIG_ARCH_HAS_PKEYS
326 # define VM_PKEY_SHIFT VM_HIGH_ARCH_BIT_0
327 # define VM_PKEY_BIT0 VM_HIGH_ARCH_0 /* A protection key is a 4-bit value */
328 # define VM_PKEY_BIT1 VM_HIGH_ARCH_1 /* on x86 and 5-bit value on ppc64 */
329 # define VM_PKEY_BIT2 VM_HIGH_ARCH_2
330 # define VM_PKEY_BIT3 VM_HIGH_ARCH_3
332 # define VM_PKEY_BIT4 VM_HIGH_ARCH_4
334 # define VM_PKEY_BIT4 0
336 #endif /* CONFIG_ARCH_HAS_PKEYS */
338 #if defined(CONFIG_X86)
339 # define VM_PAT VM_ARCH_1 /* PAT reserves whole VMA at once (x86) */
340 #elif defined(CONFIG_PPC)
341 # define VM_SAO VM_ARCH_1 /* Strong Access Ordering (powerpc) */
342 #elif defined(CONFIG_PARISC)
343 # define VM_GROWSUP VM_ARCH_1
344 #elif defined(CONFIG_IA64)
345 # define VM_GROWSUP VM_ARCH_1
346 #elif defined(CONFIG_SPARC64)
347 # define VM_SPARC_ADI VM_ARCH_1 /* Uses ADI tag for access control */
348 # define VM_ARCH_CLEAR VM_SPARC_ADI
349 #elif defined(CONFIG_ARM64)
350 # define VM_ARM64_BTI VM_ARCH_1 /* BTI guarded page, a.k.a. GP bit */
351 # define VM_ARCH_CLEAR VM_ARM64_BTI
352 #elif !defined(CONFIG_MMU)
353 # define VM_MAPPED_COPY VM_ARCH_1 /* T if mapped copy of data (nommu mmap) */
356 #if defined(CONFIG_ARM64_MTE)
357 # define VM_MTE VM_HIGH_ARCH_0 /* Use Tagged memory for access control */
358 # define VM_MTE_ALLOWED VM_HIGH_ARCH_1 /* Tagged memory permitted */
360 # define VM_MTE VM_NONE
361 # define VM_MTE_ALLOWED VM_NONE
365 # define VM_GROWSUP VM_NONE
368 #ifdef CONFIG_HAVE_ARCH_USERFAULTFD_MINOR
369 # define VM_UFFD_MINOR_BIT 37
370 # define VM_UFFD_MINOR BIT(VM_UFFD_MINOR_BIT) /* UFFD minor faults */
371 #else /* !CONFIG_HAVE_ARCH_USERFAULTFD_MINOR */
372 # define VM_UFFD_MINOR VM_NONE
373 #endif /* CONFIG_HAVE_ARCH_USERFAULTFD_MINOR */
375 /* Bits set in the VMA until the stack is in its final location */
376 #define VM_STACK_INCOMPLETE_SETUP (VM_RAND_READ | VM_SEQ_READ)
378 #define TASK_EXEC ((current->personality & READ_IMPLIES_EXEC) ? VM_EXEC : 0)
380 /* Common data flag combinations */
381 #define VM_DATA_FLAGS_TSK_EXEC (VM_READ | VM_WRITE | TASK_EXEC | \
382 VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
383 #define VM_DATA_FLAGS_NON_EXEC (VM_READ | VM_WRITE | VM_MAYREAD | \
384 VM_MAYWRITE | VM_MAYEXEC)
385 #define VM_DATA_FLAGS_EXEC (VM_READ | VM_WRITE | VM_EXEC | \
386 VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
388 #ifndef VM_DATA_DEFAULT_FLAGS /* arch can override this */
389 #define VM_DATA_DEFAULT_FLAGS VM_DATA_FLAGS_EXEC
392 #ifndef VM_STACK_DEFAULT_FLAGS /* arch can override this */
393 #define VM_STACK_DEFAULT_FLAGS VM_DATA_DEFAULT_FLAGS
396 #ifdef CONFIG_STACK_GROWSUP
397 #define VM_STACK VM_GROWSUP
399 #define VM_STACK VM_GROWSDOWN
402 #define VM_STACK_FLAGS (VM_STACK | VM_STACK_DEFAULT_FLAGS | VM_ACCOUNT)
404 /* VMA basic access permission flags */
405 #define VM_ACCESS_FLAGS (VM_READ | VM_WRITE | VM_EXEC)
409 * Special vmas that are non-mergable, non-mlock()able.
411 #define VM_SPECIAL (VM_IO | VM_DONTEXPAND | VM_PFNMAP | VM_MIXEDMAP)
413 /* This mask prevents VMA from being scanned with khugepaged */
414 #define VM_NO_KHUGEPAGED (VM_SPECIAL | VM_HUGETLB)
416 /* This mask defines which mm->def_flags a process can inherit its parent */
417 #define VM_INIT_DEF_MASK VM_NOHUGEPAGE
419 /* This mask is used to clear all the VMA flags used by mlock */
420 #define VM_LOCKED_CLEAR_MASK (~(VM_LOCKED | VM_LOCKONFAULT))
422 /* Arch-specific flags to clear when updating VM flags on protection change */
423 #ifndef VM_ARCH_CLEAR
424 # define VM_ARCH_CLEAR VM_NONE
426 #define VM_FLAGS_CLEAR (ARCH_VM_PKEY_FLAGS | VM_ARCH_CLEAR)
429 * mapping from the currently active vm_flags protection bits (the
430 * low four bits) to a page protection mask..
434 * The default fault flags that should be used by most of the
435 * arch-specific page fault handlers.
437 #define FAULT_FLAG_DEFAULT (FAULT_FLAG_ALLOW_RETRY | \
438 FAULT_FLAG_KILLABLE | \
439 FAULT_FLAG_INTERRUPTIBLE)
442 * fault_flag_allow_retry_first - check ALLOW_RETRY the first time
443 * @flags: Fault flags.
445 * This is mostly used for places where we want to try to avoid taking
446 * the mmap_lock for too long a time when waiting for another condition
447 * to change, in which case we can try to be polite to release the
448 * mmap_lock in the first round to avoid potential starvation of other
449 * processes that would also want the mmap_lock.
451 * Return: true if the page fault allows retry and this is the first
452 * attempt of the fault handling; false otherwise.
454 static inline bool fault_flag_allow_retry_first(enum fault_flag flags)
456 return (flags & FAULT_FLAG_ALLOW_RETRY) &&
457 (!(flags & FAULT_FLAG_TRIED));
460 #define FAULT_FLAG_TRACE \
461 { FAULT_FLAG_WRITE, "WRITE" }, \
462 { FAULT_FLAG_MKWRITE, "MKWRITE" }, \
463 { FAULT_FLAG_ALLOW_RETRY, "ALLOW_RETRY" }, \
464 { FAULT_FLAG_RETRY_NOWAIT, "RETRY_NOWAIT" }, \
465 { FAULT_FLAG_KILLABLE, "KILLABLE" }, \
466 { FAULT_FLAG_TRIED, "TRIED" }, \
467 { FAULT_FLAG_USER, "USER" }, \
468 { FAULT_FLAG_REMOTE, "REMOTE" }, \
469 { FAULT_FLAG_INSTRUCTION, "INSTRUCTION" }, \
470 { FAULT_FLAG_INTERRUPTIBLE, "INTERRUPTIBLE" }
473 * vm_fault is filled by the pagefault handler and passed to the vma's
474 * ->fault function. The vma's ->fault is responsible for returning a bitmask
475 * of VM_FAULT_xxx flags that give details about how the fault was handled.
477 * MM layer fills up gfp_mask for page allocations but fault handler might
478 * alter it if its implementation requires a different allocation context.
480 * pgoff should be used in favour of virtual_address, if possible.
484 struct vm_area_struct *vma; /* Target VMA */
485 gfp_t gfp_mask; /* gfp mask to be used for allocations */
486 pgoff_t pgoff; /* Logical page offset based on vma */
487 unsigned long address; /* Faulting virtual address - masked */
488 unsigned long real_address; /* Faulting virtual address - unmasked */
490 enum fault_flag flags; /* FAULT_FLAG_xxx flags
491 * XXX: should really be 'const' */
492 pmd_t *pmd; /* Pointer to pmd entry matching
494 pud_t *pud; /* Pointer to pud entry matching
498 pte_t orig_pte; /* Value of PTE at the time of fault */
499 pmd_t orig_pmd; /* Value of PMD at the time of fault,
500 * used by PMD fault only.
504 struct page *cow_page; /* Page handler may use for COW fault */
505 struct page *page; /* ->fault handlers should return a
506 * page here, unless VM_FAULT_NOPAGE
507 * is set (which is also implied by
510 /* These three entries are valid only while holding ptl lock */
511 pte_t *pte; /* Pointer to pte entry matching
512 * the 'address'. NULL if the page
513 * table hasn't been allocated.
515 spinlock_t *ptl; /* Page table lock.
516 * Protects pte page table if 'pte'
517 * is not NULL, otherwise pmd.
519 pgtable_t prealloc_pte; /* Pre-allocated pte page table.
520 * vm_ops->map_pages() sets up a page
521 * table from atomic context.
522 * do_fault_around() pre-allocates
523 * page table to avoid allocation from
528 /* page entry size for vm->huge_fault() */
529 enum page_entry_size {
536 * These are the virtual MM functions - opening of an area, closing and
537 * unmapping it (needed to keep files on disk up-to-date etc), pointer
538 * to the functions called when a no-page or a wp-page exception occurs.
540 struct vm_operations_struct {
541 void (*open)(struct vm_area_struct * area);
543 * @close: Called when the VMA is being removed from the MM.
544 * Context: User context. May sleep. Caller holds mmap_lock.
546 void (*close)(struct vm_area_struct * area);
547 /* Called any time before splitting to check if it's allowed */
548 int (*may_split)(struct vm_area_struct *area, unsigned long addr);
549 int (*mremap)(struct vm_area_struct *area);
551 * Called by mprotect() to make driver-specific permission
552 * checks before mprotect() is finalised. The VMA must not
553 * be modified. Returns 0 if mprotect() can proceed.
555 int (*mprotect)(struct vm_area_struct *vma, unsigned long start,
556 unsigned long end, unsigned long newflags);
557 vm_fault_t (*fault)(struct vm_fault *vmf);
558 vm_fault_t (*huge_fault)(struct vm_fault *vmf,
559 enum page_entry_size pe_size);
560 vm_fault_t (*map_pages)(struct vm_fault *vmf,
561 pgoff_t start_pgoff, pgoff_t end_pgoff);
562 unsigned long (*pagesize)(struct vm_area_struct * area);
564 /* notification that a previously read-only page is about to become
565 * writable, if an error is returned it will cause a SIGBUS */
566 vm_fault_t (*page_mkwrite)(struct vm_fault *vmf);
568 /* same as page_mkwrite when using VM_PFNMAP|VM_MIXEDMAP */
569 vm_fault_t (*pfn_mkwrite)(struct vm_fault *vmf);
571 /* called by access_process_vm when get_user_pages() fails, typically
572 * for use by special VMAs. See also generic_access_phys() for a generic
573 * implementation useful for any iomem mapping.
575 int (*access)(struct vm_area_struct *vma, unsigned long addr,
576 void *buf, int len, int write);
578 /* Called by the /proc/PID/maps code to ask the vma whether it
579 * has a special name. Returning non-NULL will also cause this
580 * vma to be dumped unconditionally. */
581 const char *(*name)(struct vm_area_struct *vma);
585 * set_policy() op must add a reference to any non-NULL @new mempolicy
586 * to hold the policy upon return. Caller should pass NULL @new to
587 * remove a policy and fall back to surrounding context--i.e. do not
588 * install a MPOL_DEFAULT policy, nor the task or system default
591 int (*set_policy)(struct vm_area_struct *vma, struct mempolicy *new);
594 * get_policy() op must add reference [mpol_get()] to any policy at
595 * (vma,addr) marked as MPOL_SHARED. The shared policy infrastructure
596 * in mm/mempolicy.c will do this automatically.
597 * get_policy() must NOT add a ref if the policy at (vma,addr) is not
598 * marked as MPOL_SHARED. vma policies are protected by the mmap_lock.
599 * If no [shared/vma] mempolicy exists at the addr, get_policy() op
600 * must return NULL--i.e., do not "fallback" to task or system default
603 struct mempolicy *(*get_policy)(struct vm_area_struct *vma,
607 * Called by vm_normal_page() for special PTEs to find the
608 * page for @addr. This is useful if the default behavior
609 * (using pte_page()) would not find the correct page.
611 struct page *(*find_special_page)(struct vm_area_struct *vma,
615 static inline void vma_init(struct vm_area_struct *vma, struct mm_struct *mm)
617 static const struct vm_operations_struct dummy_vm_ops = {};
619 memset(vma, 0, sizeof(*vma));
621 vma->vm_ops = &dummy_vm_ops;
622 INIT_LIST_HEAD(&vma->anon_vma_chain);
625 static inline void vma_set_anonymous(struct vm_area_struct *vma)
630 static inline bool vma_is_anonymous(struct vm_area_struct *vma)
635 static inline bool vma_is_temporary_stack(struct vm_area_struct *vma)
637 int maybe_stack = vma->vm_flags & (VM_GROWSDOWN | VM_GROWSUP);
642 if ((vma->vm_flags & VM_STACK_INCOMPLETE_SETUP) ==
643 VM_STACK_INCOMPLETE_SETUP)
649 static inline bool vma_is_foreign(struct vm_area_struct *vma)
654 if (current->mm != vma->vm_mm)
660 static inline bool vma_is_accessible(struct vm_area_struct *vma)
662 return vma->vm_flags & VM_ACCESS_FLAGS;
666 struct vm_area_struct *vma_find(struct vma_iterator *vmi, unsigned long max)
668 return mas_find(&vmi->mas, max);
671 static inline struct vm_area_struct *vma_next(struct vma_iterator *vmi)
674 * Uses vma_find() to get the first VMA when the iterator starts.
675 * Calling mas_next() could skip the first entry.
677 return vma_find(vmi, ULONG_MAX);
680 static inline struct vm_area_struct *vma_prev(struct vma_iterator *vmi)
682 return mas_prev(&vmi->mas, 0);
685 static inline unsigned long vma_iter_addr(struct vma_iterator *vmi)
687 return vmi->mas.index;
690 #define for_each_vma(__vmi, __vma) \
691 while (((__vma) = vma_next(&(__vmi))) != NULL)
693 /* The MM code likes to work with exclusive end addresses */
694 #define for_each_vma_range(__vmi, __vma, __end) \
695 while (((__vma) = vma_find(&(__vmi), (__end) - 1)) != NULL)
699 * The vma_is_shmem is not inline because it is used only by slow
700 * paths in userfault.
702 bool vma_is_shmem(struct vm_area_struct *vma);
704 static inline bool vma_is_shmem(struct vm_area_struct *vma) { return false; }
707 int vma_is_stack_for_current(struct vm_area_struct *vma);
709 /* flush_tlb_range() takes a vma, not a mm, and can care about flags */
710 #define TLB_FLUSH_VMA(mm,flags) { .vm_mm = (mm), .vm_flags = (flags) }
715 static inline unsigned int compound_order(struct page *page)
719 return page[1].compound_order;
723 * folio_order - The allocation order of a folio.
726 * A folio is composed of 2^order pages. See get_order() for the definition
729 * Return: The order of the folio.
731 static inline unsigned int folio_order(struct folio *folio)
733 if (!folio_test_large(folio))
735 return folio->_folio_order;
738 #include <linux/huge_mm.h>
741 * Methods to modify the page usage count.
743 * What counts for a page usage:
744 * - cache mapping (page->mapping)
745 * - private data (page->private)
746 * - page mapped in a task's page tables, each mapping
747 * is counted separately
749 * Also, many kernel routines increase the page count before a critical
750 * routine so they can be sure the page doesn't go away from under them.
754 * Drop a ref, return true if the refcount fell to zero (the page has no users)
756 static inline int put_page_testzero(struct page *page)
758 VM_BUG_ON_PAGE(page_ref_count(page) == 0, page);
759 return page_ref_dec_and_test(page);
762 static inline int folio_put_testzero(struct folio *folio)
764 return put_page_testzero(&folio->page);
768 * Try to grab a ref unless the page has a refcount of zero, return false if
770 * This can be called when MMU is off so it must not access
771 * any of the virtual mappings.
773 static inline bool get_page_unless_zero(struct page *page)
775 return page_ref_add_unless(page, 1, 0);
778 extern int page_is_ram(unsigned long pfn);
786 int region_intersects(resource_size_t offset, size_t size, unsigned long flags,
789 /* Support for virtually mapped pages */
790 struct page *vmalloc_to_page(const void *addr);
791 unsigned long vmalloc_to_pfn(const void *addr);
794 * Determine if an address is within the vmalloc range
796 * On nommu, vmalloc/vfree wrap through kmalloc/kfree directly, so there
797 * is no special casing required.
800 #ifndef is_ioremap_addr
801 #define is_ioremap_addr(x) is_vmalloc_addr(x)
805 extern bool is_vmalloc_addr(const void *x);
806 extern int is_vmalloc_or_module_addr(const void *x);
808 static inline bool is_vmalloc_addr(const void *x)
812 static inline int is_vmalloc_or_module_addr(const void *x)
819 * How many times the entire folio is mapped as a single unit (eg by a
820 * PMD or PUD entry). This is probably not what you want, except for
821 * debugging purposes; look at folio_mapcount() or page_mapcount()
824 static inline int folio_entire_mapcount(struct folio *folio)
826 VM_BUG_ON_FOLIO(!folio_test_large(folio), folio);
827 return atomic_read(folio_mapcount_ptr(folio)) + 1;
831 * Mapcount of compound page as a whole, does not include mapped sub-pages.
833 * Must be called only for compound pages.
835 static inline int compound_mapcount(struct page *page)
837 return folio_entire_mapcount(page_folio(page));
841 * The atomic page->_mapcount, starts from -1: so that transitions
842 * both from it and to it can be tracked, using atomic_inc_and_test
843 * and atomic_add_negative(-1).
845 static inline void page_mapcount_reset(struct page *page)
847 atomic_set(&(page)->_mapcount, -1);
850 int __page_mapcount(struct page *page);
853 * Mapcount of 0-order page; when compound sub-page, includes
854 * compound_mapcount().
856 * Result is undefined for pages which cannot be mapped into userspace.
857 * For example SLAB or special types of pages. See function page_has_type().
858 * They use this place in struct page differently.
860 static inline int page_mapcount(struct page *page)
862 if (unlikely(PageCompound(page)))
863 return __page_mapcount(page);
864 return atomic_read(&page->_mapcount) + 1;
867 int folio_mapcount(struct folio *folio);
869 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
870 static inline int total_mapcount(struct page *page)
872 return folio_mapcount(page_folio(page));
876 static inline int total_mapcount(struct page *page)
878 return page_mapcount(page);
882 static inline struct page *virt_to_head_page(const void *x)
884 struct page *page = virt_to_page(x);
886 return compound_head(page);
889 static inline struct folio *virt_to_folio(const void *x)
891 struct page *page = virt_to_page(x);
893 return page_folio(page);
896 void __folio_put(struct folio *folio);
898 void put_pages_list(struct list_head *pages);
900 void split_page(struct page *page, unsigned int order);
901 void folio_copy(struct folio *dst, struct folio *src);
903 unsigned long nr_free_buffer_pages(void);
906 * Compound pages have a destructor function. Provide a
907 * prototype for that function and accessor functions.
908 * These are _only_ valid on the head of a compound page.
910 typedef void compound_page_dtor(struct page *);
912 /* Keep the enum in sync with compound_page_dtors array in mm/page_alloc.c */
913 enum compound_dtor_id {
916 #ifdef CONFIG_HUGETLB_PAGE
919 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
924 extern compound_page_dtor * const compound_page_dtors[NR_COMPOUND_DTORS];
926 static inline void set_compound_page_dtor(struct page *page,
927 enum compound_dtor_id compound_dtor)
929 VM_BUG_ON_PAGE(compound_dtor >= NR_COMPOUND_DTORS, page);
930 page[1].compound_dtor = compound_dtor;
933 void destroy_large_folio(struct folio *folio);
935 static inline int head_compound_pincount(struct page *head)
937 return atomic_read(compound_pincount_ptr(head));
940 static inline void set_compound_order(struct page *page, unsigned int order)
942 page[1].compound_order = order;
944 page[1].compound_nr = 1U << order;
948 /* Returns the number of pages in this potentially compound page. */
949 static inline unsigned long compound_nr(struct page *page)
954 return page[1].compound_nr;
956 return 1UL << compound_order(page);
960 /* Returns the number of bytes in this potentially compound page. */
961 static inline unsigned long page_size(struct page *page)
963 return PAGE_SIZE << compound_order(page);
966 /* Returns the number of bits needed for the number of bytes in a page */
967 static inline unsigned int page_shift(struct page *page)
969 return PAGE_SHIFT + compound_order(page);
973 * thp_order - Order of a transparent huge page.
974 * @page: Head page of a transparent huge page.
976 static inline unsigned int thp_order(struct page *page)
978 VM_BUG_ON_PGFLAGS(PageTail(page), page);
979 return compound_order(page);
983 * thp_nr_pages - The number of regular pages in this huge page.
984 * @page: The head page of a huge page.
986 static inline int thp_nr_pages(struct page *page)
988 VM_BUG_ON_PGFLAGS(PageTail(page), page);
989 return compound_nr(page);
993 * thp_size - Size of a transparent huge page.
994 * @page: Head page of a transparent huge page.
996 * Return: Number of bytes in this page.
998 static inline unsigned long thp_size(struct page *page)
1000 return PAGE_SIZE << thp_order(page);
1003 void free_compound_page(struct page *page);
1007 * Do pte_mkwrite, but only if the vma says VM_WRITE. We do this when
1008 * servicing faults for write access. In the normal case, do always want
1009 * pte_mkwrite. But get_user_pages can cause write faults for mappings
1010 * that do not have writing enabled, when used by access_process_vm.
1012 static inline pte_t maybe_mkwrite(pte_t pte, struct vm_area_struct *vma)
1014 if (likely(vma->vm_flags & VM_WRITE))
1015 pte = pte_mkwrite(pte);
1019 vm_fault_t do_set_pmd(struct vm_fault *vmf, struct page *page);
1020 void do_set_pte(struct vm_fault *vmf, struct page *page, unsigned long addr);
1022 vm_fault_t finish_fault(struct vm_fault *vmf);
1023 vm_fault_t finish_mkwrite_fault(struct vm_fault *vmf);
1027 * Multiple processes may "see" the same page. E.g. for untouched
1028 * mappings of /dev/null, all processes see the same page full of
1029 * zeroes, and text pages of executables and shared libraries have
1030 * only one copy in memory, at most, normally.
1032 * For the non-reserved pages, page_count(page) denotes a reference count.
1033 * page_count() == 0 means the page is free. page->lru is then used for
1034 * freelist management in the buddy allocator.
1035 * page_count() > 0 means the page has been allocated.
1037 * Pages are allocated by the slab allocator in order to provide memory
1038 * to kmalloc and kmem_cache_alloc. In this case, the management of the
1039 * page, and the fields in 'struct page' are the responsibility of mm/slab.c
1040 * unless a particular usage is carefully commented. (the responsibility of
1041 * freeing the kmalloc memory is the caller's, of course).
1043 * A page may be used by anyone else who does a __get_free_page().
1044 * In this case, page_count still tracks the references, and should only
1045 * be used through the normal accessor functions. The top bits of page->flags
1046 * and page->virtual store page management information, but all other fields
1047 * are unused and could be used privately, carefully. The management of this
1048 * page is the responsibility of the one who allocated it, and those who have
1049 * subsequently been given references to it.
1051 * The other pages (we may call them "pagecache pages") are completely
1052 * managed by the Linux memory manager: I/O, buffers, swapping etc.
1053 * The following discussion applies only to them.
1055 * A pagecache page contains an opaque `private' member, which belongs to the
1056 * page's address_space. Usually, this is the address of a circular list of
1057 * the page's disk buffers. PG_private must be set to tell the VM to call
1058 * into the filesystem to release these pages.
1060 * A page may belong to an inode's memory mapping. In this case, page->mapping
1061 * is the pointer to the inode, and page->index is the file offset of the page,
1062 * in units of PAGE_SIZE.
1064 * If pagecache pages are not associated with an inode, they are said to be
1065 * anonymous pages. These may become associated with the swapcache, and in that
1066 * case PG_swapcache is set, and page->private is an offset into the swapcache.
1068 * In either case (swapcache or inode backed), the pagecache itself holds one
1069 * reference to the page. Setting PG_private should also increment the
1070 * refcount. The each user mapping also has a reference to the page.
1072 * The pagecache pages are stored in a per-mapping radix tree, which is
1073 * rooted at mapping->i_pages, and indexed by offset.
1074 * Where 2.4 and early 2.6 kernels kept dirty/clean pages in per-address_space
1075 * lists, we instead now tag pages as dirty/writeback in the radix tree.
1077 * All pagecache pages may be subject to I/O:
1078 * - inode pages may need to be read from disk,
1079 * - inode pages which have been modified and are MAP_SHARED may need
1080 * to be written back to the inode on disk,
1081 * - anonymous pages (including MAP_PRIVATE file mappings) which have been
1082 * modified may need to be swapped out to swap space and (later) to be read
1086 #if defined(CONFIG_ZONE_DEVICE) && defined(CONFIG_FS_DAX)
1087 DECLARE_STATIC_KEY_FALSE(devmap_managed_key);
1089 bool __put_devmap_managed_page_refs(struct page *page, int refs);
1090 static inline bool put_devmap_managed_page_refs(struct page *page, int refs)
1092 if (!static_branch_unlikely(&devmap_managed_key))
1094 if (!is_zone_device_page(page))
1096 return __put_devmap_managed_page_refs(page, refs);
1098 #else /* CONFIG_ZONE_DEVICE && CONFIG_FS_DAX */
1099 static inline bool put_devmap_managed_page_refs(struct page *page, int refs)
1103 #endif /* CONFIG_ZONE_DEVICE && CONFIG_FS_DAX */
1105 static inline bool put_devmap_managed_page(struct page *page)
1107 return put_devmap_managed_page_refs(page, 1);
1110 /* 127: arbitrary random number, small enough to assemble well */
1111 #define folio_ref_zero_or_close_to_overflow(folio) \
1112 ((unsigned int) folio_ref_count(folio) + 127u <= 127u)
1115 * folio_get - Increment the reference count on a folio.
1116 * @folio: The folio.
1118 * Context: May be called in any context, as long as you know that
1119 * you have a refcount on the folio. If you do not already have one,
1120 * folio_try_get() may be the right interface for you to use.
1122 static inline void folio_get(struct folio *folio)
1124 VM_BUG_ON_FOLIO(folio_ref_zero_or_close_to_overflow(folio), folio);
1125 folio_ref_inc(folio);
1128 static inline void get_page(struct page *page)
1130 folio_get(page_folio(page));
1133 bool __must_check try_grab_page(struct page *page, unsigned int flags);
1135 static inline __must_check bool try_get_page(struct page *page)
1137 page = compound_head(page);
1138 if (WARN_ON_ONCE(page_ref_count(page) <= 0))
1145 * folio_put - Decrement the reference count on a folio.
1146 * @folio: The folio.
1148 * If the folio's reference count reaches zero, the memory will be
1149 * released back to the page allocator and may be used by another
1150 * allocation immediately. Do not access the memory or the struct folio
1151 * after calling folio_put() unless you can be sure that it wasn't the
1154 * Context: May be called in process or interrupt context, but not in NMI
1155 * context. May be called while holding a spinlock.
1157 static inline void folio_put(struct folio *folio)
1159 if (folio_put_testzero(folio))
1164 * folio_put_refs - Reduce the reference count on a folio.
1165 * @folio: The folio.
1166 * @refs: The amount to subtract from the folio's reference count.
1168 * If the folio's reference count reaches zero, the memory will be
1169 * released back to the page allocator and may be used by another
1170 * allocation immediately. Do not access the memory or the struct folio
1171 * after calling folio_put_refs() unless you can be sure that these weren't
1172 * the last references.
1174 * Context: May be called in process or interrupt context, but not in NMI
1175 * context. May be called while holding a spinlock.
1177 static inline void folio_put_refs(struct folio *folio, int refs)
1179 if (folio_ref_sub_and_test(folio, refs))
1183 void release_pages(struct page **pages, int nr);
1186 * folios_put - Decrement the reference count on an array of folios.
1187 * @folios: The folios.
1188 * @nr: How many folios there are.
1190 * Like folio_put(), but for an array of folios. This is more efficient
1191 * than writing the loop yourself as it will optimise the locks which
1192 * need to be taken if the folios are freed.
1194 * Context: May be called in process or interrupt context, but not in NMI
1195 * context. May be called while holding a spinlock.
1197 static inline void folios_put(struct folio **folios, unsigned int nr)
1199 release_pages((struct page **)folios, nr);
1202 static inline void put_page(struct page *page)
1204 struct folio *folio = page_folio(page);
1207 * For some devmap managed pages we need to catch refcount transition
1210 if (put_devmap_managed_page(&folio->page))
1216 * GUP_PIN_COUNTING_BIAS, and the associated functions that use it, overload
1217 * the page's refcount so that two separate items are tracked: the original page
1218 * reference count, and also a new count of how many pin_user_pages() calls were
1219 * made against the page. ("gup-pinned" is another term for the latter).
1221 * With this scheme, pin_user_pages() becomes special: such pages are marked as
1222 * distinct from normal pages. As such, the unpin_user_page() call (and its
1223 * variants) must be used in order to release gup-pinned pages.
1227 * By making GUP_PIN_COUNTING_BIAS a power of two, debugging of page reference
1228 * counts with respect to pin_user_pages() and unpin_user_page() becomes
1229 * simpler, due to the fact that adding an even power of two to the page
1230 * refcount has the effect of using only the upper N bits, for the code that
1231 * counts up using the bias value. This means that the lower bits are left for
1232 * the exclusive use of the original code that increments and decrements by one
1233 * (or at least, by much smaller values than the bias value).
1235 * Of course, once the lower bits overflow into the upper bits (and this is
1236 * OK, because subtraction recovers the original values), then visual inspection
1237 * no longer suffices to directly view the separate counts. However, for normal
1238 * applications that don't have huge page reference counts, this won't be an
1241 * Locking: the lockless algorithm described in folio_try_get_rcu()
1242 * provides safe operation for get_user_pages(), page_mkclean() and
1243 * other calls that race to set up page table entries.
1245 #define GUP_PIN_COUNTING_BIAS (1U << 10)
1247 void unpin_user_page(struct page *page);
1248 void unpin_user_pages_dirty_lock(struct page **pages, unsigned long npages,
1250 void unpin_user_page_range_dirty_lock(struct page *page, unsigned long npages,
1252 void unpin_user_pages(struct page **pages, unsigned long npages);
1254 static inline bool is_cow_mapping(vm_flags_t flags)
1256 return (flags & (VM_SHARED | VM_MAYWRITE)) == VM_MAYWRITE;
1259 #if defined(CONFIG_SPARSEMEM) && !defined(CONFIG_SPARSEMEM_VMEMMAP)
1260 #define SECTION_IN_PAGE_FLAGS
1264 * The identification function is mainly used by the buddy allocator for
1265 * determining if two pages could be buddies. We are not really identifying
1266 * the zone since we could be using the section number id if we do not have
1267 * node id available in page flags.
1268 * We only guarantee that it will return the same value for two combinable
1271 static inline int page_zone_id(struct page *page)
1273 return (page->flags >> ZONEID_PGSHIFT) & ZONEID_MASK;
1276 #ifdef NODE_NOT_IN_PAGE_FLAGS
1277 extern int page_to_nid(const struct page *page);
1279 static inline int page_to_nid(const struct page *page)
1281 struct page *p = (struct page *)page;
1283 return (PF_POISONED_CHECK(p)->flags >> NODES_PGSHIFT) & NODES_MASK;
1287 static inline int folio_nid(const struct folio *folio)
1289 return page_to_nid(&folio->page);
1292 #ifdef CONFIG_NUMA_BALANCING
1293 /* page access time bits needs to hold at least 4 seconds */
1294 #define PAGE_ACCESS_TIME_MIN_BITS 12
1295 #if LAST_CPUPID_SHIFT < PAGE_ACCESS_TIME_MIN_BITS
1296 #define PAGE_ACCESS_TIME_BUCKETS \
1297 (PAGE_ACCESS_TIME_MIN_BITS - LAST_CPUPID_SHIFT)
1299 #define PAGE_ACCESS_TIME_BUCKETS 0
1302 #define PAGE_ACCESS_TIME_MASK \
1303 (LAST_CPUPID_MASK << PAGE_ACCESS_TIME_BUCKETS)
1305 static inline int cpu_pid_to_cpupid(int cpu, int pid)
1307 return ((cpu & LAST__CPU_MASK) << LAST__PID_SHIFT) | (pid & LAST__PID_MASK);
1310 static inline int cpupid_to_pid(int cpupid)
1312 return cpupid & LAST__PID_MASK;
1315 static inline int cpupid_to_cpu(int cpupid)
1317 return (cpupid >> LAST__PID_SHIFT) & LAST__CPU_MASK;
1320 static inline int cpupid_to_nid(int cpupid)
1322 return cpu_to_node(cpupid_to_cpu(cpupid));
1325 static inline bool cpupid_pid_unset(int cpupid)
1327 return cpupid_to_pid(cpupid) == (-1 & LAST__PID_MASK);
1330 static inline bool cpupid_cpu_unset(int cpupid)
1332 return cpupid_to_cpu(cpupid) == (-1 & LAST__CPU_MASK);
1335 static inline bool __cpupid_match_pid(pid_t task_pid, int cpupid)
1337 return (task_pid & LAST__PID_MASK) == cpupid_to_pid(cpupid);
1340 #define cpupid_match_pid(task, cpupid) __cpupid_match_pid(task->pid, cpupid)
1341 #ifdef LAST_CPUPID_NOT_IN_PAGE_FLAGS
1342 static inline int page_cpupid_xchg_last(struct page *page, int cpupid)
1344 return xchg(&page->_last_cpupid, cpupid & LAST_CPUPID_MASK);
1347 static inline int page_cpupid_last(struct page *page)
1349 return page->_last_cpupid;
1351 static inline void page_cpupid_reset_last(struct page *page)
1353 page->_last_cpupid = -1 & LAST_CPUPID_MASK;
1356 static inline int page_cpupid_last(struct page *page)
1358 return (page->flags >> LAST_CPUPID_PGSHIFT) & LAST_CPUPID_MASK;
1361 extern int page_cpupid_xchg_last(struct page *page, int cpupid);
1363 static inline void page_cpupid_reset_last(struct page *page)
1365 page->flags |= LAST_CPUPID_MASK << LAST_CPUPID_PGSHIFT;
1367 #endif /* LAST_CPUPID_NOT_IN_PAGE_FLAGS */
1369 static inline int xchg_page_access_time(struct page *page, int time)
1373 last_time = page_cpupid_xchg_last(page, time >> PAGE_ACCESS_TIME_BUCKETS);
1374 return last_time << PAGE_ACCESS_TIME_BUCKETS;
1376 #else /* !CONFIG_NUMA_BALANCING */
1377 static inline int page_cpupid_xchg_last(struct page *page, int cpupid)
1379 return page_to_nid(page); /* XXX */
1382 static inline int xchg_page_access_time(struct page *page, int time)
1387 static inline int page_cpupid_last(struct page *page)
1389 return page_to_nid(page); /* XXX */
1392 static inline int cpupid_to_nid(int cpupid)
1397 static inline int cpupid_to_pid(int cpupid)
1402 static inline int cpupid_to_cpu(int cpupid)
1407 static inline int cpu_pid_to_cpupid(int nid, int pid)
1412 static inline bool cpupid_pid_unset(int cpupid)
1417 static inline void page_cpupid_reset_last(struct page *page)
1421 static inline bool cpupid_match_pid(struct task_struct *task, int cpupid)
1425 #endif /* CONFIG_NUMA_BALANCING */
1427 #if defined(CONFIG_KASAN_SW_TAGS) || defined(CONFIG_KASAN_HW_TAGS)
1430 * KASAN per-page tags are stored xor'ed with 0xff. This allows to avoid
1431 * setting tags for all pages to native kernel tag value 0xff, as the default
1432 * value 0x00 maps to 0xff.
1435 static inline u8 page_kasan_tag(const struct page *page)
1439 if (kasan_enabled()) {
1440 tag = (page->flags >> KASAN_TAG_PGSHIFT) & KASAN_TAG_MASK;
1447 static inline void page_kasan_tag_set(struct page *page, u8 tag)
1449 unsigned long old_flags, flags;
1451 if (!kasan_enabled())
1455 old_flags = READ_ONCE(page->flags);
1458 flags &= ~(KASAN_TAG_MASK << KASAN_TAG_PGSHIFT);
1459 flags |= (tag & KASAN_TAG_MASK) << KASAN_TAG_PGSHIFT;
1460 } while (unlikely(!try_cmpxchg(&page->flags, &old_flags, flags)));
1463 static inline void page_kasan_tag_reset(struct page *page)
1465 if (kasan_enabled())
1466 page_kasan_tag_set(page, 0xff);
1469 #else /* CONFIG_KASAN_SW_TAGS || CONFIG_KASAN_HW_TAGS */
1471 static inline u8 page_kasan_tag(const struct page *page)
1476 static inline void page_kasan_tag_set(struct page *page, u8 tag) { }
1477 static inline void page_kasan_tag_reset(struct page *page) { }
1479 #endif /* CONFIG_KASAN_SW_TAGS || CONFIG_KASAN_HW_TAGS */
1481 static inline struct zone *page_zone(const struct page *page)
1483 return &NODE_DATA(page_to_nid(page))->node_zones[page_zonenum(page)];
1486 static inline pg_data_t *page_pgdat(const struct page *page)
1488 return NODE_DATA(page_to_nid(page));
1491 static inline struct zone *folio_zone(const struct folio *folio)
1493 return page_zone(&folio->page);
1496 static inline pg_data_t *folio_pgdat(const struct folio *folio)
1498 return page_pgdat(&folio->page);
1501 #ifdef SECTION_IN_PAGE_FLAGS
1502 static inline void set_page_section(struct page *page, unsigned long section)
1504 page->flags &= ~(SECTIONS_MASK << SECTIONS_PGSHIFT);
1505 page->flags |= (section & SECTIONS_MASK) << SECTIONS_PGSHIFT;
1508 static inline unsigned long page_to_section(const struct page *page)
1510 return (page->flags >> SECTIONS_PGSHIFT) & SECTIONS_MASK;
1515 * folio_pfn - Return the Page Frame Number of a folio.
1516 * @folio: The folio.
1518 * A folio may contain multiple pages. The pages have consecutive
1519 * Page Frame Numbers.
1521 * Return: The Page Frame Number of the first page in the folio.
1523 static inline unsigned long folio_pfn(struct folio *folio)
1525 return page_to_pfn(&folio->page);
1528 static inline struct folio *pfn_folio(unsigned long pfn)
1530 return page_folio(pfn_to_page(pfn));
1533 static inline atomic_t *folio_pincount_ptr(struct folio *folio)
1535 return &folio_page(folio, 1)->compound_pincount;
1539 * folio_maybe_dma_pinned - Report if a folio may be pinned for DMA.
1540 * @folio: The folio.
1542 * This function checks if a folio has been pinned via a call to
1543 * a function in the pin_user_pages() family.
1545 * For small folios, the return value is partially fuzzy: false is not fuzzy,
1546 * because it means "definitely not pinned for DMA", but true means "probably
1547 * pinned for DMA, but possibly a false positive due to having at least
1548 * GUP_PIN_COUNTING_BIAS worth of normal folio references".
1550 * False positives are OK, because: a) it's unlikely for a folio to
1551 * get that many refcounts, and b) all the callers of this routine are
1552 * expected to be able to deal gracefully with a false positive.
1554 * For large folios, the result will be exactly correct. That's because
1555 * we have more tracking data available: the compound_pincount is used
1556 * instead of the GUP_PIN_COUNTING_BIAS scheme.
1558 * For more information, please see Documentation/core-api/pin_user_pages.rst.
1560 * Return: True, if it is likely that the page has been "dma-pinned".
1561 * False, if the page is definitely not dma-pinned.
1563 static inline bool folio_maybe_dma_pinned(struct folio *folio)
1565 if (folio_test_large(folio))
1566 return atomic_read(folio_pincount_ptr(folio)) > 0;
1569 * folio_ref_count() is signed. If that refcount overflows, then
1570 * folio_ref_count() returns a negative value, and callers will avoid
1571 * further incrementing the refcount.
1573 * Here, for that overflow case, use the sign bit to count a little
1574 * bit higher via unsigned math, and thus still get an accurate result.
1576 return ((unsigned int)folio_ref_count(folio)) >=
1577 GUP_PIN_COUNTING_BIAS;
1580 static inline bool page_maybe_dma_pinned(struct page *page)
1582 return folio_maybe_dma_pinned(page_folio(page));
1586 * This should most likely only be called during fork() to see whether we
1587 * should break the cow immediately for an anon page on the src mm.
1589 * The caller has to hold the PT lock and the vma->vm_mm->->write_protect_seq.
1591 static inline bool page_needs_cow_for_dma(struct vm_area_struct *vma,
1594 VM_BUG_ON(!(raw_read_seqcount(&vma->vm_mm->write_protect_seq) & 1));
1596 if (!test_bit(MMF_HAS_PINNED, &vma->vm_mm->flags))
1599 return page_maybe_dma_pinned(page);
1602 /* MIGRATE_CMA and ZONE_MOVABLE do not allow pin pages */
1603 #ifdef CONFIG_MIGRATION
1604 static inline bool is_longterm_pinnable_page(struct page *page)
1607 int mt = get_pageblock_migratetype(page);
1609 if (mt == MIGRATE_CMA || mt == MIGRATE_ISOLATE)
1612 /* The zero page may always be pinned */
1613 if (is_zero_pfn(page_to_pfn(page)))
1616 /* Coherent device memory must always allow eviction. */
1617 if (is_device_coherent_page(page))
1620 /* Otherwise, non-movable zone pages can be pinned. */
1621 return !is_zone_movable_page(page);
1624 static inline bool is_longterm_pinnable_page(struct page *page)
1630 static inline bool folio_is_longterm_pinnable(struct folio *folio)
1632 return is_longterm_pinnable_page(&folio->page);
1635 static inline void set_page_zone(struct page *page, enum zone_type zone)
1637 page->flags &= ~(ZONES_MASK << ZONES_PGSHIFT);
1638 page->flags |= (zone & ZONES_MASK) << ZONES_PGSHIFT;
1641 static inline void set_page_node(struct page *page, unsigned long node)
1643 page->flags &= ~(NODES_MASK << NODES_PGSHIFT);
1644 page->flags |= (node & NODES_MASK) << NODES_PGSHIFT;
1647 static inline void set_page_links(struct page *page, enum zone_type zone,
1648 unsigned long node, unsigned long pfn)
1650 set_page_zone(page, zone);
1651 set_page_node(page, node);
1652 #ifdef SECTION_IN_PAGE_FLAGS
1653 set_page_section(page, pfn_to_section_nr(pfn));
1658 * folio_nr_pages - The number of pages in the folio.
1659 * @folio: The folio.
1661 * Return: A positive power of two.
1663 static inline long folio_nr_pages(struct folio *folio)
1665 if (!folio_test_large(folio))
1668 return folio->_folio_nr_pages;
1670 return 1L << folio->_folio_order;
1675 * folio_next - Move to the next physical folio.
1676 * @folio: The folio we're currently operating on.
1678 * If you have physically contiguous memory which may span more than
1679 * one folio (eg a &struct bio_vec), use this function to move from one
1680 * folio to the next. Do not use it if the memory is only virtually
1681 * contiguous as the folios are almost certainly not adjacent to each
1682 * other. This is the folio equivalent to writing ``page++``.
1684 * Context: We assume that the folios are refcounted and/or locked at a
1685 * higher level and do not adjust the reference counts.
1686 * Return: The next struct folio.
1688 static inline struct folio *folio_next(struct folio *folio)
1690 return (struct folio *)folio_page(folio, folio_nr_pages(folio));
1694 * folio_shift - The size of the memory described by this folio.
1695 * @folio: The folio.
1697 * A folio represents a number of bytes which is a power-of-two in size.
1698 * This function tells you which power-of-two the folio is. See also
1699 * folio_size() and folio_order().
1701 * Context: The caller should have a reference on the folio to prevent
1702 * it from being split. It is not necessary for the folio to be locked.
1703 * Return: The base-2 logarithm of the size of this folio.
1705 static inline unsigned int folio_shift(struct folio *folio)
1707 return PAGE_SHIFT + folio_order(folio);
1711 * folio_size - The number of bytes in a folio.
1712 * @folio: The folio.
1714 * Context: The caller should have a reference on the folio to prevent
1715 * it from being split. It is not necessary for the folio to be locked.
1716 * Return: The number of bytes in this folio.
1718 static inline size_t folio_size(struct folio *folio)
1720 return PAGE_SIZE << folio_order(folio);
1723 #ifndef HAVE_ARCH_MAKE_PAGE_ACCESSIBLE
1724 static inline int arch_make_page_accessible(struct page *page)
1730 #ifndef HAVE_ARCH_MAKE_FOLIO_ACCESSIBLE
1731 static inline int arch_make_folio_accessible(struct folio *folio)
1734 long i, nr = folio_nr_pages(folio);
1736 for (i = 0; i < nr; i++) {
1737 ret = arch_make_page_accessible(folio_page(folio, i));
1747 * Some inline functions in vmstat.h depend on page_zone()
1749 #include <linux/vmstat.h>
1751 static __always_inline void *lowmem_page_address(const struct page *page)
1753 return page_to_virt(page);
1756 #if defined(CONFIG_HIGHMEM) && !defined(WANT_PAGE_VIRTUAL)
1757 #define HASHED_PAGE_VIRTUAL
1760 #if defined(WANT_PAGE_VIRTUAL)
1761 static inline void *page_address(const struct page *page)
1763 return page->virtual;
1765 static inline void set_page_address(struct page *page, void *address)
1767 page->virtual = address;
1769 #define page_address_init() do { } while(0)
1772 #if defined(HASHED_PAGE_VIRTUAL)
1773 void *page_address(const struct page *page);
1774 void set_page_address(struct page *page, void *virtual);
1775 void page_address_init(void);
1778 #if !defined(HASHED_PAGE_VIRTUAL) && !defined(WANT_PAGE_VIRTUAL)
1779 #define page_address(page) lowmem_page_address(page)
1780 #define set_page_address(page, address) do { } while(0)
1781 #define page_address_init() do { } while(0)
1784 static inline void *folio_address(const struct folio *folio)
1786 return page_address(&folio->page);
1789 extern void *page_rmapping(struct page *page);
1790 extern pgoff_t __page_file_index(struct page *page);
1793 * Return the pagecache index of the passed page. Regular pagecache pages
1794 * use ->index whereas swapcache pages use swp_offset(->private)
1796 static inline pgoff_t page_index(struct page *page)
1798 if (unlikely(PageSwapCache(page)))
1799 return __page_file_index(page);
1803 bool page_mapped(struct page *page);
1804 bool folio_mapped(struct folio *folio);
1807 * Return true only if the page has been allocated with
1808 * ALLOC_NO_WATERMARKS and the low watermark was not
1809 * met implying that the system is under some pressure.
1811 static inline bool page_is_pfmemalloc(const struct page *page)
1814 * lru.next has bit 1 set if the page is allocated from the
1815 * pfmemalloc reserves. Callers may simply overwrite it if
1816 * they do not need to preserve that information.
1818 return (uintptr_t)page->lru.next & BIT(1);
1822 * Only to be called by the page allocator on a freshly allocated
1825 static inline void set_page_pfmemalloc(struct page *page)
1827 page->lru.next = (void *)BIT(1);
1830 static inline void clear_page_pfmemalloc(struct page *page)
1832 page->lru.next = NULL;
1836 * Can be called by the pagefault handler when it gets a VM_FAULT_OOM.
1838 extern void pagefault_out_of_memory(void);
1840 #define offset_in_page(p) ((unsigned long)(p) & ~PAGE_MASK)
1841 #define offset_in_thp(page, p) ((unsigned long)(p) & (thp_size(page) - 1))
1842 #define offset_in_folio(folio, p) ((unsigned long)(p) & (folio_size(folio) - 1))
1845 * Flags passed to show_mem() and show_free_areas() to suppress output in
1848 #define SHOW_MEM_FILTER_NODES (0x0001u) /* disallowed nodes */
1850 extern void __show_free_areas(unsigned int flags, nodemask_t *nodemask, int max_zone_idx);
1851 static void __maybe_unused show_free_areas(unsigned int flags, nodemask_t *nodemask)
1853 __show_free_areas(flags, nodemask, MAX_NR_ZONES - 1);
1857 * Parameter block passed down to zap_pte_range in exceptional cases.
1859 struct zap_details {
1860 struct folio *single_folio; /* Locked folio to be unmapped */
1861 bool even_cows; /* Zap COWed private pages too? */
1862 zap_flags_t zap_flags; /* Extra flags for zapping */
1866 * Whether to drop the pte markers, for example, the uffd-wp information for
1867 * file-backed memory. This should only be specified when we will completely
1868 * drop the page in the mm, either by truncation or unmapping of the vma. By
1869 * default, the flag is not set.
1871 #define ZAP_FLAG_DROP_MARKER ((__force zap_flags_t) BIT(0))
1872 /* Set in unmap_vmas() to indicate a final unmap call. Only used by hugetlb */
1873 #define ZAP_FLAG_UNMAP ((__force zap_flags_t) BIT(1))
1876 extern bool can_do_mlock(void);
1878 static inline bool can_do_mlock(void) { return false; }
1880 extern int user_shm_lock(size_t, struct ucounts *);
1881 extern void user_shm_unlock(size_t, struct ucounts *);
1883 struct page *vm_normal_page(struct vm_area_struct *vma, unsigned long addr,
1885 struct page *vm_normal_page_pmd(struct vm_area_struct *vma, unsigned long addr,
1888 void zap_vma_ptes(struct vm_area_struct *vma, unsigned long address,
1889 unsigned long size);
1890 void zap_page_range(struct vm_area_struct *vma, unsigned long address,
1891 unsigned long size);
1892 void zap_page_range_single(struct vm_area_struct *vma, unsigned long address,
1893 unsigned long size, struct zap_details *details);
1894 void unmap_vmas(struct mmu_gather *tlb, struct maple_tree *mt,
1895 struct vm_area_struct *start_vma, unsigned long start,
1898 struct mmu_notifier_range;
1900 void free_pgd_range(struct mmu_gather *tlb, unsigned long addr,
1901 unsigned long end, unsigned long floor, unsigned long ceiling);
1903 copy_page_range(struct vm_area_struct *dst_vma, struct vm_area_struct *src_vma);
1904 int follow_pte(struct mm_struct *mm, unsigned long address,
1905 pte_t **ptepp, spinlock_t **ptlp);
1906 int follow_pfn(struct vm_area_struct *vma, unsigned long address,
1907 unsigned long *pfn);
1908 int follow_phys(struct vm_area_struct *vma, unsigned long address,
1909 unsigned int flags, unsigned long *prot, resource_size_t *phys);
1910 int generic_access_phys(struct vm_area_struct *vma, unsigned long addr,
1911 void *buf, int len, int write);
1913 extern void truncate_pagecache(struct inode *inode, loff_t new);
1914 extern void truncate_setsize(struct inode *inode, loff_t newsize);
1915 void pagecache_isize_extended(struct inode *inode, loff_t from, loff_t to);
1916 void truncate_pagecache_range(struct inode *inode, loff_t offset, loff_t end);
1917 int generic_error_remove_page(struct address_space *mapping, struct page *page);
1920 extern vm_fault_t handle_mm_fault(struct vm_area_struct *vma,
1921 unsigned long address, unsigned int flags,
1922 struct pt_regs *regs);
1923 extern int fixup_user_fault(struct mm_struct *mm,
1924 unsigned long address, unsigned int fault_flags,
1926 void unmap_mapping_pages(struct address_space *mapping,
1927 pgoff_t start, pgoff_t nr, bool even_cows);
1928 void unmap_mapping_range(struct address_space *mapping,
1929 loff_t const holebegin, loff_t const holelen, int even_cows);
1931 static inline vm_fault_t handle_mm_fault(struct vm_area_struct *vma,
1932 unsigned long address, unsigned int flags,
1933 struct pt_regs *regs)
1935 /* should never happen if there's no MMU */
1937 return VM_FAULT_SIGBUS;
1939 static inline int fixup_user_fault(struct mm_struct *mm, unsigned long address,
1940 unsigned int fault_flags, bool *unlocked)
1942 /* should never happen if there's no MMU */
1946 static inline void unmap_mapping_pages(struct address_space *mapping,
1947 pgoff_t start, pgoff_t nr, bool even_cows) { }
1948 static inline void unmap_mapping_range(struct address_space *mapping,
1949 loff_t const holebegin, loff_t const holelen, int even_cows) { }
1952 static inline void unmap_shared_mapping_range(struct address_space *mapping,
1953 loff_t const holebegin, loff_t const holelen)
1955 unmap_mapping_range(mapping, holebegin, holelen, 0);
1958 extern int access_process_vm(struct task_struct *tsk, unsigned long addr,
1959 void *buf, int len, unsigned int gup_flags);
1960 extern int access_remote_vm(struct mm_struct *mm, unsigned long addr,
1961 void *buf, int len, unsigned int gup_flags);
1962 extern int __access_remote_vm(struct mm_struct *mm, unsigned long addr,
1963 void *buf, int len, unsigned int gup_flags);
1965 long get_user_pages_remote(struct mm_struct *mm,
1966 unsigned long start, unsigned long nr_pages,
1967 unsigned int gup_flags, struct page **pages,
1968 struct vm_area_struct **vmas, int *locked);
1969 long pin_user_pages_remote(struct mm_struct *mm,
1970 unsigned long start, unsigned long nr_pages,
1971 unsigned int gup_flags, struct page **pages,
1972 struct vm_area_struct **vmas, int *locked);
1973 long get_user_pages(unsigned long start, unsigned long nr_pages,
1974 unsigned int gup_flags, struct page **pages,
1975 struct vm_area_struct **vmas);
1976 long pin_user_pages(unsigned long start, unsigned long nr_pages,
1977 unsigned int gup_flags, struct page **pages,
1978 struct vm_area_struct **vmas);
1979 long get_user_pages_unlocked(unsigned long start, unsigned long nr_pages,
1980 struct page **pages, unsigned int gup_flags);
1981 long pin_user_pages_unlocked(unsigned long start, unsigned long nr_pages,
1982 struct page **pages, unsigned int gup_flags);
1984 int get_user_pages_fast(unsigned long start, int nr_pages,
1985 unsigned int gup_flags, struct page **pages);
1986 int pin_user_pages_fast(unsigned long start, int nr_pages,
1987 unsigned int gup_flags, struct page **pages);
1989 int account_locked_vm(struct mm_struct *mm, unsigned long pages, bool inc);
1990 int __account_locked_vm(struct mm_struct *mm, unsigned long pages, bool inc,
1991 struct task_struct *task, bool bypass_rlim);
1994 int get_kernel_pages(const struct kvec *iov, int nr_pages, int write,
1995 struct page **pages);
1996 struct page *get_dump_page(unsigned long addr);
1998 bool folio_mark_dirty(struct folio *folio);
1999 bool set_page_dirty(struct page *page);
2000 int set_page_dirty_lock(struct page *page);
2002 int get_cmdline(struct task_struct *task, char *buffer, int buflen);
2004 extern unsigned long move_page_tables(struct vm_area_struct *vma,
2005 unsigned long old_addr, struct vm_area_struct *new_vma,
2006 unsigned long new_addr, unsigned long len,
2007 bool need_rmap_locks);
2010 * Flags used by change_protection(). For now we make it a bitmap so
2011 * that we can pass in multiple flags just like parameters. However
2012 * for now all the callers are only use one of the flags at the same
2016 * Whether we should manually check if we can map individual PTEs writable,
2017 * because something (e.g., COW, uffd-wp) blocks that from happening for all
2018 * PTEs automatically in a writable mapping.
2020 #define MM_CP_TRY_CHANGE_WRITABLE (1UL << 0)
2021 /* Whether this protection change is for NUMA hints */
2022 #define MM_CP_PROT_NUMA (1UL << 1)
2023 /* Whether this change is for write protecting */
2024 #define MM_CP_UFFD_WP (1UL << 2) /* do wp */
2025 #define MM_CP_UFFD_WP_RESOLVE (1UL << 3) /* Resolve wp */
2026 #define MM_CP_UFFD_WP_ALL (MM_CP_UFFD_WP | \
2027 MM_CP_UFFD_WP_RESOLVE)
2029 extern unsigned long change_protection(struct mmu_gather *tlb,
2030 struct vm_area_struct *vma, unsigned long start,
2031 unsigned long end, pgprot_t newprot,
2032 unsigned long cp_flags);
2033 extern int mprotect_fixup(struct mmu_gather *tlb, struct vm_area_struct *vma,
2034 struct vm_area_struct **pprev, unsigned long start,
2035 unsigned long end, unsigned long newflags);
2038 * doesn't attempt to fault and will return short.
2040 int get_user_pages_fast_only(unsigned long start, int nr_pages,
2041 unsigned int gup_flags, struct page **pages);
2042 int pin_user_pages_fast_only(unsigned long start, int nr_pages,
2043 unsigned int gup_flags, struct page **pages);
2045 static inline bool get_user_page_fast_only(unsigned long addr,
2046 unsigned int gup_flags, struct page **pagep)
2048 return get_user_pages_fast_only(addr, 1, gup_flags, pagep) == 1;
2051 * per-process(per-mm_struct) statistics.
2053 static inline unsigned long get_mm_counter(struct mm_struct *mm, int member)
2055 long val = atomic_long_read(&mm->rss_stat.count[member]);
2057 #ifdef SPLIT_RSS_COUNTING
2059 * counter is updated in asynchronous manner and may go to minus.
2060 * But it's never be expected number for users.
2065 return (unsigned long)val;
2068 void mm_trace_rss_stat(struct mm_struct *mm, int member, long count);
2070 static inline void add_mm_counter(struct mm_struct *mm, int member, long value)
2072 long count = atomic_long_add_return(value, &mm->rss_stat.count[member]);
2074 mm_trace_rss_stat(mm, member, count);
2077 static inline void inc_mm_counter(struct mm_struct *mm, int member)
2079 long count = atomic_long_inc_return(&mm->rss_stat.count[member]);
2081 mm_trace_rss_stat(mm, member, count);
2084 static inline void dec_mm_counter(struct mm_struct *mm, int member)
2086 long count = atomic_long_dec_return(&mm->rss_stat.count[member]);
2088 mm_trace_rss_stat(mm, member, count);
2091 /* Optimized variant when page is already known not to be PageAnon */
2092 static inline int mm_counter_file(struct page *page)
2094 if (PageSwapBacked(page))
2095 return MM_SHMEMPAGES;
2096 return MM_FILEPAGES;
2099 static inline int mm_counter(struct page *page)
2102 return MM_ANONPAGES;
2103 return mm_counter_file(page);
2106 static inline unsigned long get_mm_rss(struct mm_struct *mm)
2108 return get_mm_counter(mm, MM_FILEPAGES) +
2109 get_mm_counter(mm, MM_ANONPAGES) +
2110 get_mm_counter(mm, MM_SHMEMPAGES);
2113 static inline unsigned long get_mm_hiwater_rss(struct mm_struct *mm)
2115 return max(mm->hiwater_rss, get_mm_rss(mm));
2118 static inline unsigned long get_mm_hiwater_vm(struct mm_struct *mm)
2120 return max(mm->hiwater_vm, mm->total_vm);
2123 static inline void update_hiwater_rss(struct mm_struct *mm)
2125 unsigned long _rss = get_mm_rss(mm);
2127 if ((mm)->hiwater_rss < _rss)
2128 (mm)->hiwater_rss = _rss;
2131 static inline void update_hiwater_vm(struct mm_struct *mm)
2133 if (mm->hiwater_vm < mm->total_vm)
2134 mm->hiwater_vm = mm->total_vm;
2137 static inline void reset_mm_hiwater_rss(struct mm_struct *mm)
2139 mm->hiwater_rss = get_mm_rss(mm);
2142 static inline void setmax_mm_hiwater_rss(unsigned long *maxrss,
2143 struct mm_struct *mm)
2145 unsigned long hiwater_rss = get_mm_hiwater_rss(mm);
2147 if (*maxrss < hiwater_rss)
2148 *maxrss = hiwater_rss;
2151 #if defined(SPLIT_RSS_COUNTING)
2152 void sync_mm_rss(struct mm_struct *mm);
2154 static inline void sync_mm_rss(struct mm_struct *mm)
2159 #ifndef CONFIG_ARCH_HAS_PTE_SPECIAL
2160 static inline int pte_special(pte_t pte)
2165 static inline pte_t pte_mkspecial(pte_t pte)
2171 #ifndef CONFIG_ARCH_HAS_PTE_DEVMAP
2172 static inline int pte_devmap(pte_t pte)
2178 int vma_wants_writenotify(struct vm_area_struct *vma, pgprot_t vm_page_prot);
2180 extern pte_t *__get_locked_pte(struct mm_struct *mm, unsigned long addr,
2182 static inline pte_t *get_locked_pte(struct mm_struct *mm, unsigned long addr,
2186 __cond_lock(*ptl, ptep = __get_locked_pte(mm, addr, ptl));
2190 #ifdef __PAGETABLE_P4D_FOLDED
2191 static inline int __p4d_alloc(struct mm_struct *mm, pgd_t *pgd,
2192 unsigned long address)
2197 int __p4d_alloc(struct mm_struct *mm, pgd_t *pgd, unsigned long address);
2200 #if defined(__PAGETABLE_PUD_FOLDED) || !defined(CONFIG_MMU)
2201 static inline int __pud_alloc(struct mm_struct *mm, p4d_t *p4d,
2202 unsigned long address)
2206 static inline void mm_inc_nr_puds(struct mm_struct *mm) {}
2207 static inline void mm_dec_nr_puds(struct mm_struct *mm) {}
2210 int __pud_alloc(struct mm_struct *mm, p4d_t *p4d, unsigned long address);
2212 static inline void mm_inc_nr_puds(struct mm_struct *mm)
2214 if (mm_pud_folded(mm))
2216 atomic_long_add(PTRS_PER_PUD * sizeof(pud_t), &mm->pgtables_bytes);
2219 static inline void mm_dec_nr_puds(struct mm_struct *mm)
2221 if (mm_pud_folded(mm))
2223 atomic_long_sub(PTRS_PER_PUD * sizeof(pud_t), &mm->pgtables_bytes);
2227 #if defined(__PAGETABLE_PMD_FOLDED) || !defined(CONFIG_MMU)
2228 static inline int __pmd_alloc(struct mm_struct *mm, pud_t *pud,
2229 unsigned long address)
2234 static inline void mm_inc_nr_pmds(struct mm_struct *mm) {}
2235 static inline void mm_dec_nr_pmds(struct mm_struct *mm) {}
2238 int __pmd_alloc(struct mm_struct *mm, pud_t *pud, unsigned long address);
2240 static inline void mm_inc_nr_pmds(struct mm_struct *mm)
2242 if (mm_pmd_folded(mm))
2244 atomic_long_add(PTRS_PER_PMD * sizeof(pmd_t), &mm->pgtables_bytes);
2247 static inline void mm_dec_nr_pmds(struct mm_struct *mm)
2249 if (mm_pmd_folded(mm))
2251 atomic_long_sub(PTRS_PER_PMD * sizeof(pmd_t), &mm->pgtables_bytes);
2256 static inline void mm_pgtables_bytes_init(struct mm_struct *mm)
2258 atomic_long_set(&mm->pgtables_bytes, 0);
2261 static inline unsigned long mm_pgtables_bytes(const struct mm_struct *mm)
2263 return atomic_long_read(&mm->pgtables_bytes);
2266 static inline void mm_inc_nr_ptes(struct mm_struct *mm)
2268 atomic_long_add(PTRS_PER_PTE * sizeof(pte_t), &mm->pgtables_bytes);
2271 static inline void mm_dec_nr_ptes(struct mm_struct *mm)
2273 atomic_long_sub(PTRS_PER_PTE * sizeof(pte_t), &mm->pgtables_bytes);
2277 static inline void mm_pgtables_bytes_init(struct mm_struct *mm) {}
2278 static inline unsigned long mm_pgtables_bytes(const struct mm_struct *mm)
2283 static inline void mm_inc_nr_ptes(struct mm_struct *mm) {}
2284 static inline void mm_dec_nr_ptes(struct mm_struct *mm) {}
2287 int __pte_alloc(struct mm_struct *mm, pmd_t *pmd);
2288 int __pte_alloc_kernel(pmd_t *pmd);
2290 #if defined(CONFIG_MMU)
2292 static inline p4d_t *p4d_alloc(struct mm_struct *mm, pgd_t *pgd,
2293 unsigned long address)
2295 return (unlikely(pgd_none(*pgd)) && __p4d_alloc(mm, pgd, address)) ?
2296 NULL : p4d_offset(pgd, address);
2299 static inline pud_t *pud_alloc(struct mm_struct *mm, p4d_t *p4d,
2300 unsigned long address)
2302 return (unlikely(p4d_none(*p4d)) && __pud_alloc(mm, p4d, address)) ?
2303 NULL : pud_offset(p4d, address);
2306 static inline pmd_t *pmd_alloc(struct mm_struct *mm, pud_t *pud, unsigned long address)
2308 return (unlikely(pud_none(*pud)) && __pmd_alloc(mm, pud, address))?
2309 NULL: pmd_offset(pud, address);
2311 #endif /* CONFIG_MMU */
2313 #if USE_SPLIT_PTE_PTLOCKS
2314 #if ALLOC_SPLIT_PTLOCKS
2315 void __init ptlock_cache_init(void);
2316 extern bool ptlock_alloc(struct page *page);
2317 extern void ptlock_free(struct page *page);
2319 static inline spinlock_t *ptlock_ptr(struct page *page)
2323 #else /* ALLOC_SPLIT_PTLOCKS */
2324 static inline void ptlock_cache_init(void)
2328 static inline bool ptlock_alloc(struct page *page)
2333 static inline void ptlock_free(struct page *page)
2337 static inline spinlock_t *ptlock_ptr(struct page *page)
2341 #endif /* ALLOC_SPLIT_PTLOCKS */
2343 static inline spinlock_t *pte_lockptr(struct mm_struct *mm, pmd_t *pmd)
2345 return ptlock_ptr(pmd_page(*pmd));
2348 static inline bool ptlock_init(struct page *page)
2351 * prep_new_page() initialize page->private (and therefore page->ptl)
2352 * with 0. Make sure nobody took it in use in between.
2354 * It can happen if arch try to use slab for page table allocation:
2355 * slab code uses page->slab_cache, which share storage with page->ptl.
2357 VM_BUG_ON_PAGE(*(unsigned long *)&page->ptl, page);
2358 if (!ptlock_alloc(page))
2360 spin_lock_init(ptlock_ptr(page));
2364 #else /* !USE_SPLIT_PTE_PTLOCKS */
2366 * We use mm->page_table_lock to guard all pagetable pages of the mm.
2368 static inline spinlock_t *pte_lockptr(struct mm_struct *mm, pmd_t *pmd)
2370 return &mm->page_table_lock;
2372 static inline void ptlock_cache_init(void) {}
2373 static inline bool ptlock_init(struct page *page) { return true; }
2374 static inline void ptlock_free(struct page *page) {}
2375 #endif /* USE_SPLIT_PTE_PTLOCKS */
2377 static inline void pgtable_init(void)
2379 ptlock_cache_init();
2380 pgtable_cache_init();
2383 static inline bool pgtable_pte_page_ctor(struct page *page)
2385 if (!ptlock_init(page))
2387 __SetPageTable(page);
2388 inc_lruvec_page_state(page, NR_PAGETABLE);
2392 static inline void pgtable_pte_page_dtor(struct page *page)
2395 __ClearPageTable(page);
2396 dec_lruvec_page_state(page, NR_PAGETABLE);
2399 #define pte_offset_map_lock(mm, pmd, address, ptlp) \
2401 spinlock_t *__ptl = pte_lockptr(mm, pmd); \
2402 pte_t *__pte = pte_offset_map(pmd, address); \
2408 #define pte_unmap_unlock(pte, ptl) do { \
2413 #define pte_alloc(mm, pmd) (unlikely(pmd_none(*(pmd))) && __pte_alloc(mm, pmd))
2415 #define pte_alloc_map(mm, pmd, address) \
2416 (pte_alloc(mm, pmd) ? NULL : pte_offset_map(pmd, address))
2418 #define pte_alloc_map_lock(mm, pmd, address, ptlp) \
2419 (pte_alloc(mm, pmd) ? \
2420 NULL : pte_offset_map_lock(mm, pmd, address, ptlp))
2422 #define pte_alloc_kernel(pmd, address) \
2423 ((unlikely(pmd_none(*(pmd))) && __pte_alloc_kernel(pmd))? \
2424 NULL: pte_offset_kernel(pmd, address))
2426 #if USE_SPLIT_PMD_PTLOCKS
2428 static struct page *pmd_to_page(pmd_t *pmd)
2430 unsigned long mask = ~(PTRS_PER_PMD * sizeof(pmd_t) - 1);
2431 return virt_to_page((void *)((unsigned long) pmd & mask));
2434 static inline spinlock_t *pmd_lockptr(struct mm_struct *mm, pmd_t *pmd)
2436 return ptlock_ptr(pmd_to_page(pmd));
2439 static inline bool pmd_ptlock_init(struct page *page)
2441 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
2442 page->pmd_huge_pte = NULL;
2444 return ptlock_init(page);
2447 static inline void pmd_ptlock_free(struct page *page)
2449 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
2450 VM_BUG_ON_PAGE(page->pmd_huge_pte, page);
2455 #define pmd_huge_pte(mm, pmd) (pmd_to_page(pmd)->pmd_huge_pte)
2459 static inline spinlock_t *pmd_lockptr(struct mm_struct *mm, pmd_t *pmd)
2461 return &mm->page_table_lock;
2464 static inline bool pmd_ptlock_init(struct page *page) { return true; }
2465 static inline void pmd_ptlock_free(struct page *page) {}
2467 #define pmd_huge_pte(mm, pmd) ((mm)->pmd_huge_pte)
2471 static inline spinlock_t *pmd_lock(struct mm_struct *mm, pmd_t *pmd)
2473 spinlock_t *ptl = pmd_lockptr(mm, pmd);
2478 static inline bool pgtable_pmd_page_ctor(struct page *page)
2480 if (!pmd_ptlock_init(page))
2482 __SetPageTable(page);
2483 inc_lruvec_page_state(page, NR_PAGETABLE);
2487 static inline void pgtable_pmd_page_dtor(struct page *page)
2489 pmd_ptlock_free(page);
2490 __ClearPageTable(page);
2491 dec_lruvec_page_state(page, NR_PAGETABLE);
2495 * No scalability reason to split PUD locks yet, but follow the same pattern
2496 * as the PMD locks to make it easier if we decide to. The VM should not be
2497 * considered ready to switch to split PUD locks yet; there may be places
2498 * which need to be converted from page_table_lock.
2500 static inline spinlock_t *pud_lockptr(struct mm_struct *mm, pud_t *pud)
2502 return &mm->page_table_lock;
2505 static inline spinlock_t *pud_lock(struct mm_struct *mm, pud_t *pud)
2507 spinlock_t *ptl = pud_lockptr(mm, pud);
2513 extern void __init pagecache_init(void);
2514 extern void free_initmem(void);
2517 * Free reserved pages within range [PAGE_ALIGN(start), end & PAGE_MASK)
2518 * into the buddy system. The freed pages will be poisoned with pattern
2519 * "poison" if it's within range [0, UCHAR_MAX].
2520 * Return pages freed into the buddy system.
2522 extern unsigned long free_reserved_area(void *start, void *end,
2523 int poison, const char *s);
2525 extern void adjust_managed_page_count(struct page *page, long count);
2526 extern void mem_init_print_info(void);
2528 extern void reserve_bootmem_region(phys_addr_t start, phys_addr_t end);
2530 /* Free the reserved page into the buddy system, so it gets managed. */
2531 static inline void free_reserved_page(struct page *page)
2533 ClearPageReserved(page);
2534 init_page_count(page);
2536 adjust_managed_page_count(page, 1);
2538 #define free_highmem_page(page) free_reserved_page(page)
2540 static inline void mark_page_reserved(struct page *page)
2542 SetPageReserved(page);
2543 adjust_managed_page_count(page, -1);
2547 * Default method to free all the __init memory into the buddy system.
2548 * The freed pages will be poisoned with pattern "poison" if it's within
2549 * range [0, UCHAR_MAX].
2550 * Return pages freed into the buddy system.
2552 static inline unsigned long free_initmem_default(int poison)
2554 extern char __init_begin[], __init_end[];
2556 return free_reserved_area(&__init_begin, &__init_end,
2557 poison, "unused kernel image (initmem)");
2560 static inline unsigned long get_num_physpages(void)
2563 unsigned long phys_pages = 0;
2565 for_each_online_node(nid)
2566 phys_pages += node_present_pages(nid);
2572 * Using memblock node mappings, an architecture may initialise its
2573 * zones, allocate the backing mem_map and account for memory holes in an
2574 * architecture independent manner.
2576 * An architecture is expected to register range of page frames backed by
2577 * physical memory with memblock_add[_node]() before calling
2578 * free_area_init() passing in the PFN each zone ends at. At a basic
2579 * usage, an architecture is expected to do something like
2581 * unsigned long max_zone_pfns[MAX_NR_ZONES] = {max_dma, max_normal_pfn,
2583 * for_each_valid_physical_page_range()
2584 * memblock_add_node(base, size, nid, MEMBLOCK_NONE)
2585 * free_area_init(max_zone_pfns);
2587 void free_area_init(unsigned long *max_zone_pfn);
2588 unsigned long node_map_pfn_alignment(void);
2589 unsigned long __absent_pages_in_range(int nid, unsigned long start_pfn,
2590 unsigned long end_pfn);
2591 extern unsigned long absent_pages_in_range(unsigned long start_pfn,
2592 unsigned long end_pfn);
2593 extern void get_pfn_range_for_nid(unsigned int nid,
2594 unsigned long *start_pfn, unsigned long *end_pfn);
2597 static inline int early_pfn_to_nid(unsigned long pfn)
2602 /* please see mm/page_alloc.c */
2603 extern int __meminit early_pfn_to_nid(unsigned long pfn);
2606 extern void set_dma_reserve(unsigned long new_dma_reserve);
2607 extern void memmap_init_range(unsigned long, int, unsigned long,
2608 unsigned long, unsigned long, enum meminit_context,
2609 struct vmem_altmap *, int migratetype);
2610 extern void setup_per_zone_wmarks(void);
2611 extern void calculate_min_free_kbytes(void);
2612 extern int __meminit init_per_zone_wmark_min(void);
2613 extern void mem_init(void);
2614 extern void __init mmap_init(void);
2616 extern void __show_mem(unsigned int flags, nodemask_t *nodemask, int max_zone_idx);
2617 static inline void show_mem(unsigned int flags, nodemask_t *nodemask)
2619 __show_mem(flags, nodemask, MAX_NR_ZONES - 1);
2621 extern long si_mem_available(void);
2622 extern void si_meminfo(struct sysinfo * val);
2623 extern void si_meminfo_node(struct sysinfo *val, int nid);
2624 #ifdef __HAVE_ARCH_RESERVED_KERNEL_PAGES
2625 extern unsigned long arch_reserved_kernel_pages(void);
2628 extern __printf(3, 4)
2629 void warn_alloc(gfp_t gfp_mask, nodemask_t *nodemask, const char *fmt, ...);
2631 extern void setup_per_cpu_pageset(void);
2634 extern int min_free_kbytes;
2635 extern int watermark_boost_factor;
2636 extern int watermark_scale_factor;
2637 extern bool arch_has_descending_max_zone_pfns(void);
2640 extern atomic_long_t mmap_pages_allocated;
2641 extern int nommu_shrink_inode_mappings(struct inode *, size_t, size_t);
2643 /* interval_tree.c */
2644 void vma_interval_tree_insert(struct vm_area_struct *node,
2645 struct rb_root_cached *root);
2646 void vma_interval_tree_insert_after(struct vm_area_struct *node,
2647 struct vm_area_struct *prev,
2648 struct rb_root_cached *root);
2649 void vma_interval_tree_remove(struct vm_area_struct *node,
2650 struct rb_root_cached *root);
2651 struct vm_area_struct *vma_interval_tree_iter_first(struct rb_root_cached *root,
2652 unsigned long start, unsigned long last);
2653 struct vm_area_struct *vma_interval_tree_iter_next(struct vm_area_struct *node,
2654 unsigned long start, unsigned long last);
2656 #define vma_interval_tree_foreach(vma, root, start, last) \
2657 for (vma = vma_interval_tree_iter_first(root, start, last); \
2658 vma; vma = vma_interval_tree_iter_next(vma, start, last))
2660 void anon_vma_interval_tree_insert(struct anon_vma_chain *node,
2661 struct rb_root_cached *root);
2662 void anon_vma_interval_tree_remove(struct anon_vma_chain *node,
2663 struct rb_root_cached *root);
2664 struct anon_vma_chain *
2665 anon_vma_interval_tree_iter_first(struct rb_root_cached *root,
2666 unsigned long start, unsigned long last);
2667 struct anon_vma_chain *anon_vma_interval_tree_iter_next(
2668 struct anon_vma_chain *node, unsigned long start, unsigned long last);
2669 #ifdef CONFIG_DEBUG_VM_RB
2670 void anon_vma_interval_tree_verify(struct anon_vma_chain *node);
2673 #define anon_vma_interval_tree_foreach(avc, root, start, last) \
2674 for (avc = anon_vma_interval_tree_iter_first(root, start, last); \
2675 avc; avc = anon_vma_interval_tree_iter_next(avc, start, last))
2678 extern int __vm_enough_memory(struct mm_struct *mm, long pages, int cap_sys_admin);
2679 extern int __vma_adjust(struct vm_area_struct *vma, unsigned long start,
2680 unsigned long end, pgoff_t pgoff, struct vm_area_struct *insert,
2681 struct vm_area_struct *expand);
2682 static inline int vma_adjust(struct vm_area_struct *vma, unsigned long start,
2683 unsigned long end, pgoff_t pgoff, struct vm_area_struct *insert)
2685 return __vma_adjust(vma, start, end, pgoff, insert, NULL);
2687 extern struct vm_area_struct *vma_merge(struct mm_struct *,
2688 struct vm_area_struct *prev, unsigned long addr, unsigned long end,
2689 unsigned long vm_flags, struct anon_vma *, struct file *, pgoff_t,
2690 struct mempolicy *, struct vm_userfaultfd_ctx, struct anon_vma_name *);
2691 extern struct anon_vma *find_mergeable_anon_vma(struct vm_area_struct *);
2692 extern int __split_vma(struct mm_struct *, struct vm_area_struct *,
2693 unsigned long addr, int new_below);
2694 extern int split_vma(struct mm_struct *, struct vm_area_struct *,
2695 unsigned long addr, int new_below);
2696 extern int insert_vm_struct(struct mm_struct *, struct vm_area_struct *);
2697 extern void unlink_file_vma(struct vm_area_struct *);
2698 extern struct vm_area_struct *copy_vma(struct vm_area_struct **,
2699 unsigned long addr, unsigned long len, pgoff_t pgoff,
2700 bool *need_rmap_locks);
2701 extern void exit_mmap(struct mm_struct *);
2703 void vma_mas_store(struct vm_area_struct *vma, struct ma_state *mas);
2704 void vma_mas_remove(struct vm_area_struct *vma, struct ma_state *mas);
2706 static inline int check_data_rlimit(unsigned long rlim,
2708 unsigned long start,
2709 unsigned long end_data,
2710 unsigned long start_data)
2712 if (rlim < RLIM_INFINITY) {
2713 if (((new - start) + (end_data - start_data)) > rlim)
2720 extern int mm_take_all_locks(struct mm_struct *mm);
2721 extern void mm_drop_all_locks(struct mm_struct *mm);
2723 extern int set_mm_exe_file(struct mm_struct *mm, struct file *new_exe_file);
2724 extern int replace_mm_exe_file(struct mm_struct *mm, struct file *new_exe_file);
2725 extern struct file *get_mm_exe_file(struct mm_struct *mm);
2726 extern struct file *get_task_exe_file(struct task_struct *task);
2728 extern bool may_expand_vm(struct mm_struct *, vm_flags_t, unsigned long npages);
2729 extern void vm_stat_account(struct mm_struct *, vm_flags_t, long npages);
2731 extern bool vma_is_special_mapping(const struct vm_area_struct *vma,
2732 const struct vm_special_mapping *sm);
2733 extern struct vm_area_struct *_install_special_mapping(struct mm_struct *mm,
2734 unsigned long addr, unsigned long len,
2735 unsigned long flags,
2736 const struct vm_special_mapping *spec);
2737 /* This is an obsolete alternative to _install_special_mapping. */
2738 extern int install_special_mapping(struct mm_struct *mm,
2739 unsigned long addr, unsigned long len,
2740 unsigned long flags, struct page **pages);
2742 unsigned long randomize_stack_top(unsigned long stack_top);
2743 unsigned long randomize_page(unsigned long start, unsigned long range);
2745 extern unsigned long get_unmapped_area(struct file *, unsigned long, unsigned long, unsigned long, unsigned long);
2747 extern unsigned long mmap_region(struct file *file, unsigned long addr,
2748 unsigned long len, vm_flags_t vm_flags, unsigned long pgoff,
2749 struct list_head *uf);
2750 extern unsigned long do_mmap(struct file *file, unsigned long addr,
2751 unsigned long len, unsigned long prot, unsigned long flags,
2752 unsigned long pgoff, unsigned long *populate, struct list_head *uf);
2753 extern int do_mas_munmap(struct ma_state *mas, struct mm_struct *mm,
2754 unsigned long start, size_t len, struct list_head *uf,
2756 extern int do_munmap(struct mm_struct *, unsigned long, size_t,
2757 struct list_head *uf);
2758 extern int do_madvise(struct mm_struct *mm, unsigned long start, size_t len_in, int behavior);
2761 extern int __mm_populate(unsigned long addr, unsigned long len,
2763 static inline void mm_populate(unsigned long addr, unsigned long len)
2766 (void) __mm_populate(addr, len, 1);
2769 static inline void mm_populate(unsigned long addr, unsigned long len) {}
2772 /* These take the mm semaphore themselves */
2773 extern int __must_check vm_brk(unsigned long, unsigned long);
2774 extern int __must_check vm_brk_flags(unsigned long, unsigned long, unsigned long);
2775 extern int vm_munmap(unsigned long, size_t);
2776 extern unsigned long __must_check vm_mmap(struct file *, unsigned long,
2777 unsigned long, unsigned long,
2778 unsigned long, unsigned long);
2780 struct vm_unmapped_area_info {
2781 #define VM_UNMAPPED_AREA_TOPDOWN 1
2782 unsigned long flags;
2783 unsigned long length;
2784 unsigned long low_limit;
2785 unsigned long high_limit;
2786 unsigned long align_mask;
2787 unsigned long align_offset;
2790 extern unsigned long vm_unmapped_area(struct vm_unmapped_area_info *info);
2793 extern void truncate_inode_pages(struct address_space *, loff_t);
2794 extern void truncate_inode_pages_range(struct address_space *,
2795 loff_t lstart, loff_t lend);
2796 extern void truncate_inode_pages_final(struct address_space *);
2798 /* generic vm_area_ops exported for stackable file systems */
2799 extern vm_fault_t filemap_fault(struct vm_fault *vmf);
2800 extern vm_fault_t filemap_map_pages(struct vm_fault *vmf,
2801 pgoff_t start_pgoff, pgoff_t end_pgoff);
2802 extern vm_fault_t filemap_page_mkwrite(struct vm_fault *vmf);
2804 extern unsigned long stack_guard_gap;
2805 /* Generic expand stack which grows the stack according to GROWS{UP,DOWN} */
2806 extern int expand_stack(struct vm_area_struct *vma, unsigned long address);
2808 /* CONFIG_STACK_GROWSUP still needs to grow downwards at some places */
2809 extern int expand_downwards(struct vm_area_struct *vma,
2810 unsigned long address);
2812 extern int expand_upwards(struct vm_area_struct *vma, unsigned long address);
2814 #define expand_upwards(vma, address) (0)
2817 /* Look up the first VMA which satisfies addr < vm_end, NULL if none. */
2818 extern struct vm_area_struct * find_vma(struct mm_struct * mm, unsigned long addr);
2819 extern struct vm_area_struct * find_vma_prev(struct mm_struct * mm, unsigned long addr,
2820 struct vm_area_struct **pprev);
2823 * Look up the first VMA which intersects the interval [start_addr, end_addr)
2824 * NULL if none. Assume start_addr < end_addr.
2826 struct vm_area_struct *find_vma_intersection(struct mm_struct *mm,
2827 unsigned long start_addr, unsigned long end_addr);
2830 * vma_lookup() - Find a VMA at a specific address
2831 * @mm: The process address space.
2832 * @addr: The user address.
2834 * Return: The vm_area_struct at the given address, %NULL otherwise.
2837 struct vm_area_struct *vma_lookup(struct mm_struct *mm, unsigned long addr)
2839 return mtree_load(&mm->mm_mt, addr);
2842 static inline unsigned long vm_start_gap(struct vm_area_struct *vma)
2844 unsigned long vm_start = vma->vm_start;
2846 if (vma->vm_flags & VM_GROWSDOWN) {
2847 vm_start -= stack_guard_gap;
2848 if (vm_start > vma->vm_start)
2854 static inline unsigned long vm_end_gap(struct vm_area_struct *vma)
2856 unsigned long vm_end = vma->vm_end;
2858 if (vma->vm_flags & VM_GROWSUP) {
2859 vm_end += stack_guard_gap;
2860 if (vm_end < vma->vm_end)
2861 vm_end = -PAGE_SIZE;
2866 static inline unsigned long vma_pages(struct vm_area_struct *vma)
2868 return (vma->vm_end - vma->vm_start) >> PAGE_SHIFT;
2871 /* Look up the first VMA which exactly match the interval vm_start ... vm_end */
2872 static inline struct vm_area_struct *find_exact_vma(struct mm_struct *mm,
2873 unsigned long vm_start, unsigned long vm_end)
2875 struct vm_area_struct *vma = vma_lookup(mm, vm_start);
2877 if (vma && (vma->vm_start != vm_start || vma->vm_end != vm_end))
2883 static inline bool range_in_vma(struct vm_area_struct *vma,
2884 unsigned long start, unsigned long end)
2886 return (vma && vma->vm_start <= start && end <= vma->vm_end);
2890 pgprot_t vm_get_page_prot(unsigned long vm_flags);
2891 void vma_set_page_prot(struct vm_area_struct *vma);
2893 static inline pgprot_t vm_get_page_prot(unsigned long vm_flags)
2897 static inline void vma_set_page_prot(struct vm_area_struct *vma)
2899 vma->vm_page_prot = vm_get_page_prot(vma->vm_flags);
2903 void vma_set_file(struct vm_area_struct *vma, struct file *file);
2905 #ifdef CONFIG_NUMA_BALANCING
2906 unsigned long change_prot_numa(struct vm_area_struct *vma,
2907 unsigned long start, unsigned long end);
2910 struct vm_area_struct *find_extend_vma(struct mm_struct *, unsigned long addr);
2911 int remap_pfn_range(struct vm_area_struct *, unsigned long addr,
2912 unsigned long pfn, unsigned long size, pgprot_t);
2913 int remap_pfn_range_notrack(struct vm_area_struct *vma, unsigned long addr,
2914 unsigned long pfn, unsigned long size, pgprot_t prot);
2915 int vm_insert_page(struct vm_area_struct *, unsigned long addr, struct page *);
2916 int vm_insert_pages(struct vm_area_struct *vma, unsigned long addr,
2917 struct page **pages, unsigned long *num);
2918 int vm_map_pages(struct vm_area_struct *vma, struct page **pages,
2920 int vm_map_pages_zero(struct vm_area_struct *vma, struct page **pages,
2922 vm_fault_t vmf_insert_pfn(struct vm_area_struct *vma, unsigned long addr,
2924 vm_fault_t vmf_insert_pfn_prot(struct vm_area_struct *vma, unsigned long addr,
2925 unsigned long pfn, pgprot_t pgprot);
2926 vm_fault_t vmf_insert_mixed(struct vm_area_struct *vma, unsigned long addr,
2928 vm_fault_t vmf_insert_mixed_prot(struct vm_area_struct *vma, unsigned long addr,
2929 pfn_t pfn, pgprot_t pgprot);
2930 vm_fault_t vmf_insert_mixed_mkwrite(struct vm_area_struct *vma,
2931 unsigned long addr, pfn_t pfn);
2932 int vm_iomap_memory(struct vm_area_struct *vma, phys_addr_t start, unsigned long len);
2934 static inline vm_fault_t vmf_insert_page(struct vm_area_struct *vma,
2935 unsigned long addr, struct page *page)
2937 int err = vm_insert_page(vma, addr, page);
2940 return VM_FAULT_OOM;
2941 if (err < 0 && err != -EBUSY)
2942 return VM_FAULT_SIGBUS;
2944 return VM_FAULT_NOPAGE;
2947 #ifndef io_remap_pfn_range
2948 static inline int io_remap_pfn_range(struct vm_area_struct *vma,
2949 unsigned long addr, unsigned long pfn,
2950 unsigned long size, pgprot_t prot)
2952 return remap_pfn_range(vma, addr, pfn, size, pgprot_decrypted(prot));
2956 static inline vm_fault_t vmf_error(int err)
2959 return VM_FAULT_OOM;
2960 return VM_FAULT_SIGBUS;
2963 struct page *follow_page(struct vm_area_struct *vma, unsigned long address,
2964 unsigned int foll_flags);
2966 #define FOLL_WRITE 0x01 /* check pte is writable */
2967 #define FOLL_TOUCH 0x02 /* mark page accessed */
2968 #define FOLL_GET 0x04 /* do get_page on page */
2969 #define FOLL_DUMP 0x08 /* give error on hole if it would be zero */
2970 #define FOLL_FORCE 0x10 /* get_user_pages read/write w/o permission */
2971 #define FOLL_NOWAIT 0x20 /* if a disk transfer is needed, start the IO
2972 * and return without waiting upon it */
2973 #define FOLL_NOFAULT 0x80 /* do not fault in pages */
2974 #define FOLL_HWPOISON 0x100 /* check page is hwpoisoned */
2975 #define FOLL_MIGRATION 0x400 /* wait for page to replace migration entry */
2976 #define FOLL_TRIED 0x800 /* a retry, previous pass started an IO */
2977 #define FOLL_REMOTE 0x2000 /* we are working on non-current tsk/mm */
2978 #define FOLL_ANON 0x8000 /* don't do file mappings */
2979 #define FOLL_LONGTERM 0x10000 /* mapping lifetime is indefinite: see below */
2980 #define FOLL_SPLIT_PMD 0x20000 /* split huge pmd before returning */
2981 #define FOLL_PIN 0x40000 /* pages must be released via unpin_user_page */
2982 #define FOLL_FAST_ONLY 0x80000 /* gup_fast: prevent fall-back to slow gup */
2985 * FOLL_PIN and FOLL_LONGTERM may be used in various combinations with each
2986 * other. Here is what they mean, and how to use them:
2988 * FOLL_LONGTERM indicates that the page will be held for an indefinite time
2989 * period _often_ under userspace control. This is in contrast to
2990 * iov_iter_get_pages(), whose usages are transient.
2992 * FIXME: For pages which are part of a filesystem, mappings are subject to the
2993 * lifetime enforced by the filesystem and we need guarantees that longterm
2994 * users like RDMA and V4L2 only establish mappings which coordinate usage with
2995 * the filesystem. Ideas for this coordination include revoking the longterm
2996 * pin, delaying writeback, bounce buffer page writeback, etc. As FS DAX was
2997 * added after the problem with filesystems was found FS DAX VMAs are
2998 * specifically failed. Filesystem pages are still subject to bugs and use of
2999 * FOLL_LONGTERM should be avoided on those pages.
3001 * FIXME: Also NOTE that FOLL_LONGTERM is not supported in every GUP call.
3002 * Currently only get_user_pages() and get_user_pages_fast() support this flag
3003 * and calls to get_user_pages_[un]locked are specifically not allowed. This
3004 * is due to an incompatibility with the FS DAX check and
3005 * FAULT_FLAG_ALLOW_RETRY.
3007 * In the CMA case: long term pins in a CMA region would unnecessarily fragment
3008 * that region. And so, CMA attempts to migrate the page before pinning, when
3009 * FOLL_LONGTERM is specified.
3011 * FOLL_PIN indicates that a special kind of tracking (not just page->_refcount,
3012 * but an additional pin counting system) will be invoked. This is intended for
3013 * anything that gets a page reference and then touches page data (for example,
3014 * Direct IO). This lets the filesystem know that some non-file-system entity is
3015 * potentially changing the pages' data. In contrast to FOLL_GET (whose pages
3016 * are released via put_page()), FOLL_PIN pages must be released, ultimately, by
3017 * a call to unpin_user_page().
3019 * FOLL_PIN is similar to FOLL_GET: both of these pin pages. They use different
3020 * and separate refcounting mechanisms, however, and that means that each has
3021 * its own acquire and release mechanisms:
3023 * FOLL_GET: get_user_pages*() to acquire, and put_page() to release.
3025 * FOLL_PIN: pin_user_pages*() to acquire, and unpin_user_pages to release.
3027 * FOLL_PIN and FOLL_GET are mutually exclusive for a given function call.
3028 * (The underlying pages may experience both FOLL_GET-based and FOLL_PIN-based
3029 * calls applied to them, and that's perfectly OK. This is a constraint on the
3030 * callers, not on the pages.)
3032 * FOLL_PIN should be set internally by the pin_user_pages*() APIs, never
3033 * directly by the caller. That's in order to help avoid mismatches when
3034 * releasing pages: get_user_pages*() pages must be released via put_page(),
3035 * while pin_user_pages*() pages must be released via unpin_user_page().
3037 * Please see Documentation/core-api/pin_user_pages.rst for more information.
3040 static inline int vm_fault_to_errno(vm_fault_t vm_fault, int foll_flags)
3042 if (vm_fault & VM_FAULT_OOM)
3044 if (vm_fault & (VM_FAULT_HWPOISON | VM_FAULT_HWPOISON_LARGE))
3045 return (foll_flags & FOLL_HWPOISON) ? -EHWPOISON : -EFAULT;
3046 if (vm_fault & (VM_FAULT_SIGBUS | VM_FAULT_SIGSEGV))
3052 * Indicates for which pages that are write-protected in the page table,
3053 * whether GUP has to trigger unsharing via FAULT_FLAG_UNSHARE such that the
3054 * GUP pin will remain consistent with the pages mapped into the page tables
3057 * Temporary unmapping of PageAnonExclusive() pages or clearing of
3058 * PageAnonExclusive() has to protect against concurrent GUP:
3059 * * Ordinary GUP: Using the PT lock
3060 * * GUP-fast and fork(): mm->write_protect_seq
3061 * * GUP-fast and KSM or temporary unmapping (swap, migration): see
3062 * page_try_share_anon_rmap()
3064 * Must be called with the (sub)page that's actually referenced via the
3065 * page table entry, which might not necessarily be the head page for a
3068 static inline bool gup_must_unshare(unsigned int flags, struct page *page)
3071 * FOLL_WRITE is implicitly handled correctly as the page table entry
3072 * has to be writable -- and if it references (part of) an anonymous
3073 * folio, that part is required to be marked exclusive.
3075 if ((flags & (FOLL_WRITE | FOLL_PIN)) != FOLL_PIN)
3078 * Note: PageAnon(page) is stable until the page is actually getting
3081 if (!PageAnon(page))
3084 /* Paired with a memory barrier in page_try_share_anon_rmap(). */
3085 if (IS_ENABLED(CONFIG_HAVE_FAST_GUP))
3089 * Note that PageKsm() pages cannot be exclusive, and consequently,
3090 * cannot get pinned.
3092 return !PageAnonExclusive(page);
3096 * Indicates whether GUP can follow a PROT_NONE mapped page, or whether
3097 * a (NUMA hinting) fault is required.
3099 static inline bool gup_can_follow_protnone(unsigned int flags)
3102 * FOLL_FORCE has to be able to make progress even if the VMA is
3103 * inaccessible. Further, FOLL_FORCE access usually does not represent
3104 * application behaviour and we should avoid triggering NUMA hinting
3107 return flags & FOLL_FORCE;
3110 typedef int (*pte_fn_t)(pte_t *pte, unsigned long addr, void *data);
3111 extern int apply_to_page_range(struct mm_struct *mm, unsigned long address,
3112 unsigned long size, pte_fn_t fn, void *data);
3113 extern int apply_to_existing_page_range(struct mm_struct *mm,
3114 unsigned long address, unsigned long size,
3115 pte_fn_t fn, void *data);
3117 extern void __init init_mem_debugging_and_hardening(void);
3118 #ifdef CONFIG_PAGE_POISONING
3119 extern void __kernel_poison_pages(struct page *page, int numpages);
3120 extern void __kernel_unpoison_pages(struct page *page, int numpages);
3121 extern bool _page_poisoning_enabled_early;
3122 DECLARE_STATIC_KEY_FALSE(_page_poisoning_enabled);
3123 static inline bool page_poisoning_enabled(void)
3125 return _page_poisoning_enabled_early;
3128 * For use in fast paths after init_mem_debugging() has run, or when a
3129 * false negative result is not harmful when called too early.
3131 static inline bool page_poisoning_enabled_static(void)
3133 return static_branch_unlikely(&_page_poisoning_enabled);
3135 static inline void kernel_poison_pages(struct page *page, int numpages)
3137 if (page_poisoning_enabled_static())
3138 __kernel_poison_pages(page, numpages);
3140 static inline void kernel_unpoison_pages(struct page *page, int numpages)
3142 if (page_poisoning_enabled_static())
3143 __kernel_unpoison_pages(page, numpages);
3146 static inline bool page_poisoning_enabled(void) { return false; }
3147 static inline bool page_poisoning_enabled_static(void) { return false; }
3148 static inline void __kernel_poison_pages(struct page *page, int nunmpages) { }
3149 static inline void kernel_poison_pages(struct page *page, int numpages) { }
3150 static inline void kernel_unpoison_pages(struct page *page, int numpages) { }
3153 DECLARE_STATIC_KEY_MAYBE(CONFIG_INIT_ON_ALLOC_DEFAULT_ON, init_on_alloc);
3154 static inline bool want_init_on_alloc(gfp_t flags)
3156 if (static_branch_maybe(CONFIG_INIT_ON_ALLOC_DEFAULT_ON,
3159 return flags & __GFP_ZERO;
3162 DECLARE_STATIC_KEY_MAYBE(CONFIG_INIT_ON_FREE_DEFAULT_ON, init_on_free);
3163 static inline bool want_init_on_free(void)
3165 return static_branch_maybe(CONFIG_INIT_ON_FREE_DEFAULT_ON,
3169 extern bool _debug_pagealloc_enabled_early;
3170 DECLARE_STATIC_KEY_FALSE(_debug_pagealloc_enabled);
3172 static inline bool debug_pagealloc_enabled(void)
3174 return IS_ENABLED(CONFIG_DEBUG_PAGEALLOC) &&
3175 _debug_pagealloc_enabled_early;
3179 * For use in fast paths after init_debug_pagealloc() has run, or when a
3180 * false negative result is not harmful when called too early.
3182 static inline bool debug_pagealloc_enabled_static(void)
3184 if (!IS_ENABLED(CONFIG_DEBUG_PAGEALLOC))
3187 return static_branch_unlikely(&_debug_pagealloc_enabled);
3190 #ifdef CONFIG_DEBUG_PAGEALLOC
3192 * To support DEBUG_PAGEALLOC architecture must ensure that
3193 * __kernel_map_pages() never fails
3195 extern void __kernel_map_pages(struct page *page, int numpages, int enable);
3197 static inline void debug_pagealloc_map_pages(struct page *page, int numpages)
3199 if (debug_pagealloc_enabled_static())
3200 __kernel_map_pages(page, numpages, 1);
3203 static inline void debug_pagealloc_unmap_pages(struct page *page, int numpages)
3205 if (debug_pagealloc_enabled_static())
3206 __kernel_map_pages(page, numpages, 0);
3208 #else /* CONFIG_DEBUG_PAGEALLOC */
3209 static inline void debug_pagealloc_map_pages(struct page *page, int numpages) {}
3210 static inline void debug_pagealloc_unmap_pages(struct page *page, int numpages) {}
3211 #endif /* CONFIG_DEBUG_PAGEALLOC */
3213 #ifdef __HAVE_ARCH_GATE_AREA
3214 extern struct vm_area_struct *get_gate_vma(struct mm_struct *mm);
3215 extern int in_gate_area_no_mm(unsigned long addr);
3216 extern int in_gate_area(struct mm_struct *mm, unsigned long addr);
3218 static inline struct vm_area_struct *get_gate_vma(struct mm_struct *mm)
3222 static inline int in_gate_area_no_mm(unsigned long addr) { return 0; }
3223 static inline int in_gate_area(struct mm_struct *mm, unsigned long addr)
3227 #endif /* __HAVE_ARCH_GATE_AREA */
3229 extern bool process_shares_mm(struct task_struct *p, struct mm_struct *mm);
3231 #ifdef CONFIG_SYSCTL
3232 extern int sysctl_drop_caches;
3233 int drop_caches_sysctl_handler(struct ctl_table *, int, void *, size_t *,
3237 void drop_slab(void);
3240 #define randomize_va_space 0
3242 extern int randomize_va_space;
3245 const char * arch_vma_name(struct vm_area_struct *vma);
3247 void print_vma_addr(char *prefix, unsigned long rip);
3249 static inline void print_vma_addr(char *prefix, unsigned long rip)
3254 void *sparse_buffer_alloc(unsigned long size);
3255 struct page * __populate_section_memmap(unsigned long pfn,
3256 unsigned long nr_pages, int nid, struct vmem_altmap *altmap,
3257 struct dev_pagemap *pgmap);
3258 pgd_t *vmemmap_pgd_populate(unsigned long addr, int node);
3259 p4d_t *vmemmap_p4d_populate(pgd_t *pgd, unsigned long addr, int node);
3260 pud_t *vmemmap_pud_populate(p4d_t *p4d, unsigned long addr, int node);
3261 pmd_t *vmemmap_pmd_populate(pud_t *pud, unsigned long addr, int node);
3262 pte_t *vmemmap_pte_populate(pmd_t *pmd, unsigned long addr, int node,
3263 struct vmem_altmap *altmap, struct page *reuse);
3264 void *vmemmap_alloc_block(unsigned long size, int node);
3266 void *vmemmap_alloc_block_buf(unsigned long size, int node,
3267 struct vmem_altmap *altmap);
3268 void vmemmap_verify(pte_t *, int, unsigned long, unsigned long);
3269 int vmemmap_populate_basepages(unsigned long start, unsigned long end,
3270 int node, struct vmem_altmap *altmap);
3271 int vmemmap_populate(unsigned long start, unsigned long end, int node,
3272 struct vmem_altmap *altmap);
3273 void vmemmap_populate_print_last(void);
3274 #ifdef CONFIG_MEMORY_HOTPLUG
3275 void vmemmap_free(unsigned long start, unsigned long end,
3276 struct vmem_altmap *altmap);
3278 void register_page_bootmem_memmap(unsigned long section_nr, struct page *map,
3279 unsigned long nr_pages);
3282 MF_COUNT_INCREASED = 1 << 0,
3283 MF_ACTION_REQUIRED = 1 << 1,
3284 MF_MUST_KILL = 1 << 2,
3285 MF_SOFT_OFFLINE = 1 << 3,
3286 MF_UNPOISON = 1 << 4,
3287 MF_SW_SIMULATED = 1 << 5,
3288 MF_NO_RETRY = 1 << 6,
3290 int mf_dax_kill_procs(struct address_space *mapping, pgoff_t index,
3291 unsigned long count, int mf_flags);
3292 extern int memory_failure(unsigned long pfn, int flags);
3293 extern void memory_failure_queue(unsigned long pfn, int flags);
3294 extern void memory_failure_queue_kick(int cpu);
3295 extern int unpoison_memory(unsigned long pfn);
3296 extern int sysctl_memory_failure_early_kill;
3297 extern int sysctl_memory_failure_recovery;
3298 extern void shake_page(struct page *p);
3299 extern atomic_long_t num_poisoned_pages __read_mostly;
3300 extern int soft_offline_page(unsigned long pfn, int flags);
3301 #ifdef CONFIG_MEMORY_FAILURE
3302 extern int __get_huge_page_for_hwpoison(unsigned long pfn, int flags,
3303 bool *migratable_cleared);
3304 void num_poisoned_pages_inc(unsigned long pfn);
3305 void num_poisoned_pages_sub(unsigned long pfn, long i);
3307 static inline int __get_huge_page_for_hwpoison(unsigned long pfn, int flags,
3308 bool *migratable_cleared)
3313 static inline void num_poisoned_pages_inc(unsigned long pfn)
3317 static inline void num_poisoned_pages_sub(unsigned long pfn, long i)
3322 #if defined(CONFIG_MEMORY_FAILURE) && defined(CONFIG_MEMORY_HOTPLUG)
3323 extern void memblk_nr_poison_inc(unsigned long pfn);
3324 extern void memblk_nr_poison_sub(unsigned long pfn, long i);
3326 static inline void memblk_nr_poison_inc(unsigned long pfn)
3330 static inline void memblk_nr_poison_sub(unsigned long pfn, long i)
3335 #ifndef arch_memory_failure
3336 static inline int arch_memory_failure(unsigned long pfn, int flags)
3342 #ifndef arch_is_platform_page
3343 static inline bool arch_is_platform_page(u64 paddr)
3350 * Error handlers for various types of pages.
3353 MF_IGNORED, /* Error: cannot be handled */
3354 MF_FAILED, /* Error: handling failed */
3355 MF_DELAYED, /* Will be handled later */
3356 MF_RECOVERED, /* Successfully recovered */
3359 enum mf_action_page_type {
3361 MF_MSG_KERNEL_HIGH_ORDER,
3363 MF_MSG_DIFFERENT_COMPOUND,
3366 MF_MSG_UNMAP_FAILED,
3367 MF_MSG_DIRTY_SWAPCACHE,
3368 MF_MSG_CLEAN_SWAPCACHE,
3369 MF_MSG_DIRTY_MLOCKED_LRU,
3370 MF_MSG_CLEAN_MLOCKED_LRU,
3371 MF_MSG_DIRTY_UNEVICTABLE_LRU,
3372 MF_MSG_CLEAN_UNEVICTABLE_LRU,
3375 MF_MSG_TRUNCATED_LRU,
3382 #if defined(CONFIG_TRANSPARENT_HUGEPAGE) || defined(CONFIG_HUGETLBFS)
3383 extern void clear_huge_page(struct page *page,
3384 unsigned long addr_hint,
3385 unsigned int pages_per_huge_page);
3386 extern void copy_user_huge_page(struct page *dst, struct page *src,
3387 unsigned long addr_hint,
3388 struct vm_area_struct *vma,
3389 unsigned int pages_per_huge_page);
3390 extern long copy_huge_page_from_user(struct page *dst_page,
3391 const void __user *usr_src,
3392 unsigned int pages_per_huge_page,
3393 bool allow_pagefault);
3396 * vma_is_special_huge - Are transhuge page-table entries considered special?
3397 * @vma: Pointer to the struct vm_area_struct to consider
3399 * Whether transhuge page-table entries are considered "special" following
3400 * the definition in vm_normal_page().
3402 * Return: true if transhuge page-table entries should be considered special,
3405 static inline bool vma_is_special_huge(const struct vm_area_struct *vma)
3407 return vma_is_dax(vma) || (vma->vm_file &&
3408 (vma->vm_flags & (VM_PFNMAP | VM_MIXEDMAP)));
3411 #endif /* CONFIG_TRANSPARENT_HUGEPAGE || CONFIG_HUGETLBFS */
3413 #ifdef CONFIG_DEBUG_PAGEALLOC
3414 extern unsigned int _debug_guardpage_minorder;
3415 DECLARE_STATIC_KEY_FALSE(_debug_guardpage_enabled);
3417 static inline unsigned int debug_guardpage_minorder(void)
3419 return _debug_guardpage_minorder;
3422 static inline bool debug_guardpage_enabled(void)
3424 return static_branch_unlikely(&_debug_guardpage_enabled);
3427 static inline bool page_is_guard(struct page *page)
3429 if (!debug_guardpage_enabled())
3432 return PageGuard(page);
3435 static inline unsigned int debug_guardpage_minorder(void) { return 0; }
3436 static inline bool debug_guardpage_enabled(void) { return false; }
3437 static inline bool page_is_guard(struct page *page) { return false; }
3438 #endif /* CONFIG_DEBUG_PAGEALLOC */
3440 #if MAX_NUMNODES > 1
3441 void __init setup_nr_node_ids(void);
3443 static inline void setup_nr_node_ids(void) {}
3446 extern int memcmp_pages(struct page *page1, struct page *page2);
3448 static inline int pages_identical(struct page *page1, struct page *page2)
3450 return !memcmp_pages(page1, page2);
3453 #ifdef CONFIG_MAPPING_DIRTY_HELPERS
3454 unsigned long clean_record_shared_mapping_range(struct address_space *mapping,
3455 pgoff_t first_index, pgoff_t nr,
3456 pgoff_t bitmap_pgoff,
3457 unsigned long *bitmap,
3461 unsigned long wp_shared_mapping_range(struct address_space *mapping,
3462 pgoff_t first_index, pgoff_t nr);
3465 extern int sysctl_nr_trim_pages;
3467 #ifdef CONFIG_PRINTK
3468 void mem_dump_obj(void *object);
3470 static inline void mem_dump_obj(void *object) {}
3474 * seal_check_future_write - Check for F_SEAL_FUTURE_WRITE flag and handle it
3475 * @seals: the seals to check
3476 * @vma: the vma to operate on
3478 * Check whether F_SEAL_FUTURE_WRITE is set; if so, do proper check/handling on
3479 * the vma flags. Return 0 if check pass, or <0 for errors.
3481 static inline int seal_check_future_write(int seals, struct vm_area_struct *vma)
3483 if (seals & F_SEAL_FUTURE_WRITE) {
3485 * New PROT_WRITE and MAP_SHARED mmaps are not allowed when
3486 * "future write" seal active.
3488 if ((vma->vm_flags & VM_SHARED) && (vma->vm_flags & VM_WRITE))
3492 * Since an F_SEAL_FUTURE_WRITE sealed memfd can be mapped as
3493 * MAP_SHARED and read-only, take care to not allow mprotect to
3494 * revert protections on such mappings. Do this only for shared
3495 * mappings. For private mappings, don't need to mask
3496 * VM_MAYWRITE as we still want them to be COW-writable.
3498 if (vma->vm_flags & VM_SHARED)
3499 vma->vm_flags &= ~(VM_MAYWRITE);
3505 #ifdef CONFIG_ANON_VMA_NAME
3506 int madvise_set_anon_name(struct mm_struct *mm, unsigned long start,
3507 unsigned long len_in,
3508 struct anon_vma_name *anon_name);
3511 madvise_set_anon_name(struct mm_struct *mm, unsigned long start,
3512 unsigned long len_in, struct anon_vma_name *anon_name) {
3517 #endif /* _LINUX_MM_H */