1 /* SPDX-License-Identifier: GPL-2.0 */
5 #include <linux/errno.h>
9 #include <linux/mmdebug.h>
10 #include <linux/gfp.h>
11 #include <linux/bug.h>
12 #include <linux/list.h>
13 #include <linux/mmzone.h>
14 #include <linux/rbtree.h>
15 #include <linux/atomic.h>
16 #include <linux/debug_locks.h>
17 #include <linux/mm_types.h>
18 #include <linux/mmap_lock.h>
19 #include <linux/range.h>
20 #include <linux/pfn.h>
21 #include <linux/percpu-refcount.h>
22 #include <linux/bit_spinlock.h>
23 #include <linux/shrinker.h>
24 #include <linux/resource.h>
25 #include <linux/page_ext.h>
26 #include <linux/err.h>
27 #include <linux/page-flags.h>
28 #include <linux/page_ref.h>
29 #include <linux/memremap.h>
30 #include <linux/overflow.h>
31 #include <linux/sizes.h>
32 #include <linux/sched.h>
33 #include <linux/pgtable.h>
34 #include <linux/kasan.h>
38 struct anon_vma_chain;
41 struct writeback_control;
45 extern int sysctl_page_lock_unfairness;
47 void init_mm_internals(void);
49 #ifndef CONFIG_NUMA /* Don't use mapnrs, do it properly */
50 extern unsigned long max_mapnr;
52 static inline void set_max_mapnr(unsigned long limit)
57 static inline void set_max_mapnr(unsigned long limit) { }
60 extern atomic_long_t _totalram_pages;
61 static inline unsigned long totalram_pages(void)
63 return (unsigned long)atomic_long_read(&_totalram_pages);
66 static inline void totalram_pages_inc(void)
68 atomic_long_inc(&_totalram_pages);
71 static inline void totalram_pages_dec(void)
73 atomic_long_dec(&_totalram_pages);
76 static inline void totalram_pages_add(long count)
78 atomic_long_add(count, &_totalram_pages);
81 extern void * high_memory;
82 extern int page_cluster;
85 extern int sysctl_legacy_va_layout;
87 #define sysctl_legacy_va_layout 0
90 #ifdef CONFIG_HAVE_ARCH_MMAP_RND_BITS
91 extern const int mmap_rnd_bits_min;
92 extern const int mmap_rnd_bits_max;
93 extern int mmap_rnd_bits __read_mostly;
95 #ifdef CONFIG_HAVE_ARCH_MMAP_RND_COMPAT_BITS
96 extern const int mmap_rnd_compat_bits_min;
97 extern const int mmap_rnd_compat_bits_max;
98 extern int mmap_rnd_compat_bits __read_mostly;
101 #include <asm/page.h>
102 #include <asm/processor.h>
105 * Architectures that support memory tagging (assigning tags to memory regions,
106 * embedding these tags into addresses that point to these memory regions, and
107 * checking that the memory and the pointer tags match on memory accesses)
108 * redefine this macro to strip tags from pointers.
109 * It's defined as noop for architectures that don't support memory tagging.
111 #ifndef untagged_addr
112 #define untagged_addr(addr) (addr)
116 #define __pa_symbol(x) __pa(RELOC_HIDE((unsigned long)(x), 0))
120 #define page_to_virt(x) __va(PFN_PHYS(page_to_pfn(x)))
124 #define lm_alias(x) __va(__pa_symbol(x))
128 * To prevent common memory management code establishing
129 * a zero page mapping on a read fault.
130 * This macro should be defined within <asm/pgtable.h>.
131 * s390 does this to prevent multiplexing of hardware bits
132 * related to the physical page in case of virtualization.
134 #ifndef mm_forbids_zeropage
135 #define mm_forbids_zeropage(X) (0)
139 * On some architectures it is expensive to call memset() for small sizes.
140 * If an architecture decides to implement their own version of
141 * mm_zero_struct_page they should wrap the defines below in a #ifndef and
142 * define their own version of this macro in <asm/pgtable.h>
144 #if BITS_PER_LONG == 64
145 /* This function must be updated when the size of struct page grows above 80
146 * or reduces below 56. The idea that compiler optimizes out switch()
147 * statement, and only leaves move/store instructions. Also the compiler can
148 * combine write statements if they are both assignments and can be reordered,
149 * this can result in several of the writes here being dropped.
151 #define mm_zero_struct_page(pp) __mm_zero_struct_page(pp)
152 static inline void __mm_zero_struct_page(struct page *page)
154 unsigned long *_pp = (void *)page;
156 /* Check that struct page is either 56, 64, 72, or 80 bytes */
157 BUILD_BUG_ON(sizeof(struct page) & 7);
158 BUILD_BUG_ON(sizeof(struct page) < 56);
159 BUILD_BUG_ON(sizeof(struct page) > 80);
161 switch (sizeof(struct page)) {
182 #define mm_zero_struct_page(pp) ((void)memset((pp), 0, sizeof(struct page)))
186 * Default maximum number of active map areas, this limits the number of vmas
187 * per mm struct. Users can overwrite this number by sysctl but there is a
190 * When a program's coredump is generated as ELF format, a section is created
191 * per a vma. In ELF, the number of sections is represented in unsigned short.
192 * This means the number of sections should be smaller than 65535 at coredump.
193 * Because the kernel adds some informative sections to a image of program at
194 * generating coredump, we need some margin. The number of extra sections is
195 * 1-3 now and depends on arch. We use "5" as safe margin, here.
197 * ELF extended numbering allows more than 65535 sections, so 16-bit bound is
198 * not a hard limit any more. Although some userspace tools can be surprised by
201 #define MAPCOUNT_ELF_CORE_MARGIN (5)
202 #define DEFAULT_MAX_MAP_COUNT (USHRT_MAX - MAPCOUNT_ELF_CORE_MARGIN)
204 extern int sysctl_max_map_count;
206 extern unsigned long sysctl_user_reserve_kbytes;
207 extern unsigned long sysctl_admin_reserve_kbytes;
209 extern int sysctl_overcommit_memory;
210 extern int sysctl_overcommit_ratio;
211 extern unsigned long sysctl_overcommit_kbytes;
213 int overcommit_ratio_handler(struct ctl_table *, int, void *, size_t *,
215 int overcommit_kbytes_handler(struct ctl_table *, int, void *, size_t *,
217 int overcommit_policy_handler(struct ctl_table *, int, void *, size_t *,
220 * Any attempt to mark this function as static leads to build failure
221 * when CONFIG_DEBUG_INFO_BTF is enabled because __add_to_page_cache_locked()
222 * is referred to by BPF code. This must be visible for error injection.
224 int __add_to_page_cache_locked(struct page *page, struct address_space *mapping,
225 pgoff_t index, gfp_t gfp, void **shadowp);
227 #if defined(CONFIG_SPARSEMEM) && !defined(CONFIG_SPARSEMEM_VMEMMAP)
228 #define nth_page(page,n) pfn_to_page(page_to_pfn((page)) + (n))
230 #define nth_page(page,n) ((page) + (n))
233 /* to align the pointer to the (next) page boundary */
234 #define PAGE_ALIGN(addr) ALIGN(addr, PAGE_SIZE)
236 /* test whether an address (unsigned long or pointer) is aligned to PAGE_SIZE */
237 #define PAGE_ALIGNED(addr) IS_ALIGNED((unsigned long)(addr), PAGE_SIZE)
239 #define lru_to_page(head) (list_entry((head)->prev, struct page, lru))
241 void setup_initial_init_mm(void *start_code, void *end_code,
242 void *end_data, void *brk);
245 * Linux kernel virtual memory manager primitives.
246 * The idea being to have a "virtual" mm in the same way
247 * we have a virtual fs - giving a cleaner interface to the
248 * mm details, and allowing different kinds of memory mappings
249 * (from shared memory to executable loading to arbitrary
253 struct vm_area_struct *vm_area_alloc(struct mm_struct *);
254 struct vm_area_struct *vm_area_dup(struct vm_area_struct *);
255 void vm_area_free(struct vm_area_struct *);
258 extern struct rb_root nommu_region_tree;
259 extern struct rw_semaphore nommu_region_sem;
261 extern unsigned int kobjsize(const void *objp);
265 * vm_flags in vm_area_struct, see mm_types.h.
266 * When changing, update also include/trace/events/mmflags.h
268 #define VM_NONE 0x00000000
270 #define VM_READ 0x00000001 /* currently active flags */
271 #define VM_WRITE 0x00000002
272 #define VM_EXEC 0x00000004
273 #define VM_SHARED 0x00000008
275 /* mprotect() hardcodes VM_MAYREAD >> 4 == VM_READ, and so for r/w/x bits. */
276 #define VM_MAYREAD 0x00000010 /* limits for mprotect() etc */
277 #define VM_MAYWRITE 0x00000020
278 #define VM_MAYEXEC 0x00000040
279 #define VM_MAYSHARE 0x00000080
281 #define VM_GROWSDOWN 0x00000100 /* general info on the segment */
282 #define VM_UFFD_MISSING 0x00000200 /* missing pages tracking */
283 #define VM_PFNMAP 0x00000400 /* Page-ranges managed without "struct page", just pure PFN */
284 #define VM_DENYWRITE 0x00000800 /* ETXTBSY on write attempts.. */
285 #define VM_UFFD_WP 0x00001000 /* wrprotect pages tracking */
287 #define VM_LOCKED 0x00002000
288 #define VM_IO 0x00004000 /* Memory mapped I/O or similar */
290 /* Used by sys_madvise() */
291 #define VM_SEQ_READ 0x00008000 /* App will access data sequentially */
292 #define VM_RAND_READ 0x00010000 /* App will not benefit from clustered reads */
294 #define VM_DONTCOPY 0x00020000 /* Do not copy this vma on fork */
295 #define VM_DONTEXPAND 0x00040000 /* Cannot expand with mremap() */
296 #define VM_LOCKONFAULT 0x00080000 /* Lock the pages covered when they are faulted in */
297 #define VM_ACCOUNT 0x00100000 /* Is a VM accounted object */
298 #define VM_NORESERVE 0x00200000 /* should the VM suppress accounting */
299 #define VM_HUGETLB 0x00400000 /* Huge TLB Page VM */
300 #define VM_SYNC 0x00800000 /* Synchronous page faults */
301 #define VM_ARCH_1 0x01000000 /* Architecture-specific flag */
302 #define VM_WIPEONFORK 0x02000000 /* Wipe VMA contents in child. */
303 #define VM_DONTDUMP 0x04000000 /* Do not include in the core dump */
305 #ifdef CONFIG_MEM_SOFT_DIRTY
306 # define VM_SOFTDIRTY 0x08000000 /* Not soft dirty clean area */
308 # define VM_SOFTDIRTY 0
311 #define VM_MIXEDMAP 0x10000000 /* Can contain "struct page" and pure PFN pages */
312 #define VM_HUGEPAGE 0x20000000 /* MADV_HUGEPAGE marked this vma */
313 #define VM_NOHUGEPAGE 0x40000000 /* MADV_NOHUGEPAGE marked this vma */
314 #define VM_MERGEABLE 0x80000000 /* KSM may merge identical pages */
316 #ifdef CONFIG_ARCH_USES_HIGH_VMA_FLAGS
317 #define VM_HIGH_ARCH_BIT_0 32 /* bit only usable on 64-bit architectures */
318 #define VM_HIGH_ARCH_BIT_1 33 /* bit only usable on 64-bit architectures */
319 #define VM_HIGH_ARCH_BIT_2 34 /* bit only usable on 64-bit architectures */
320 #define VM_HIGH_ARCH_BIT_3 35 /* bit only usable on 64-bit architectures */
321 #define VM_HIGH_ARCH_BIT_4 36 /* bit only usable on 64-bit architectures */
322 #define VM_HIGH_ARCH_0 BIT(VM_HIGH_ARCH_BIT_0)
323 #define VM_HIGH_ARCH_1 BIT(VM_HIGH_ARCH_BIT_1)
324 #define VM_HIGH_ARCH_2 BIT(VM_HIGH_ARCH_BIT_2)
325 #define VM_HIGH_ARCH_3 BIT(VM_HIGH_ARCH_BIT_3)
326 #define VM_HIGH_ARCH_4 BIT(VM_HIGH_ARCH_BIT_4)
327 #endif /* CONFIG_ARCH_USES_HIGH_VMA_FLAGS */
329 #ifdef CONFIG_ARCH_HAS_PKEYS
330 # define VM_PKEY_SHIFT VM_HIGH_ARCH_BIT_0
331 # define VM_PKEY_BIT0 VM_HIGH_ARCH_0 /* A protection key is a 4-bit value */
332 # define VM_PKEY_BIT1 VM_HIGH_ARCH_1 /* on x86 and 5-bit value on ppc64 */
333 # define VM_PKEY_BIT2 VM_HIGH_ARCH_2
334 # define VM_PKEY_BIT3 VM_HIGH_ARCH_3
336 # define VM_PKEY_BIT4 VM_HIGH_ARCH_4
338 # define VM_PKEY_BIT4 0
340 #endif /* CONFIG_ARCH_HAS_PKEYS */
342 #if defined(CONFIG_X86)
343 # define VM_PAT VM_ARCH_1 /* PAT reserves whole VMA at once (x86) */
344 #elif defined(CONFIG_PPC)
345 # define VM_SAO VM_ARCH_1 /* Strong Access Ordering (powerpc) */
346 #elif defined(CONFIG_PARISC)
347 # define VM_GROWSUP VM_ARCH_1
348 #elif defined(CONFIG_IA64)
349 # define VM_GROWSUP VM_ARCH_1
350 #elif defined(CONFIG_SPARC64)
351 # define VM_SPARC_ADI VM_ARCH_1 /* Uses ADI tag for access control */
352 # define VM_ARCH_CLEAR VM_SPARC_ADI
353 #elif defined(CONFIG_ARM64)
354 # define VM_ARM64_BTI VM_ARCH_1 /* BTI guarded page, a.k.a. GP bit */
355 # define VM_ARCH_CLEAR VM_ARM64_BTI
356 #elif !defined(CONFIG_MMU)
357 # define VM_MAPPED_COPY VM_ARCH_1 /* T if mapped copy of data (nommu mmap) */
360 #if defined(CONFIG_ARM64_MTE)
361 # define VM_MTE VM_HIGH_ARCH_0 /* Use Tagged memory for access control */
362 # define VM_MTE_ALLOWED VM_HIGH_ARCH_1 /* Tagged memory permitted */
364 # define VM_MTE VM_NONE
365 # define VM_MTE_ALLOWED VM_NONE
369 # define VM_GROWSUP VM_NONE
372 #ifdef CONFIG_HAVE_ARCH_USERFAULTFD_MINOR
373 # define VM_UFFD_MINOR_BIT 37
374 # define VM_UFFD_MINOR BIT(VM_UFFD_MINOR_BIT) /* UFFD minor faults */
375 #else /* !CONFIG_HAVE_ARCH_USERFAULTFD_MINOR */
376 # define VM_UFFD_MINOR VM_NONE
377 #endif /* CONFIG_HAVE_ARCH_USERFAULTFD_MINOR */
379 /* Bits set in the VMA until the stack is in its final location */
380 #define VM_STACK_INCOMPLETE_SETUP (VM_RAND_READ | VM_SEQ_READ)
382 #define TASK_EXEC ((current->personality & READ_IMPLIES_EXEC) ? VM_EXEC : 0)
384 /* Common data flag combinations */
385 #define VM_DATA_FLAGS_TSK_EXEC (VM_READ | VM_WRITE | TASK_EXEC | \
386 VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
387 #define VM_DATA_FLAGS_NON_EXEC (VM_READ | VM_WRITE | VM_MAYREAD | \
388 VM_MAYWRITE | VM_MAYEXEC)
389 #define VM_DATA_FLAGS_EXEC (VM_READ | VM_WRITE | VM_EXEC | \
390 VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC)
392 #ifndef VM_DATA_DEFAULT_FLAGS /* arch can override this */
393 #define VM_DATA_DEFAULT_FLAGS VM_DATA_FLAGS_EXEC
396 #ifndef VM_STACK_DEFAULT_FLAGS /* arch can override this */
397 #define VM_STACK_DEFAULT_FLAGS VM_DATA_DEFAULT_FLAGS
400 #ifdef CONFIG_STACK_GROWSUP
401 #define VM_STACK VM_GROWSUP
403 #define VM_STACK VM_GROWSDOWN
406 #define VM_STACK_FLAGS (VM_STACK | VM_STACK_DEFAULT_FLAGS | VM_ACCOUNT)
408 /* VMA basic access permission flags */
409 #define VM_ACCESS_FLAGS (VM_READ | VM_WRITE | VM_EXEC)
413 * Special vmas that are non-mergable, non-mlock()able.
415 #define VM_SPECIAL (VM_IO | VM_DONTEXPAND | VM_PFNMAP | VM_MIXEDMAP)
417 /* This mask prevents VMA from being scanned with khugepaged */
418 #define VM_NO_KHUGEPAGED (VM_SPECIAL | VM_HUGETLB)
420 /* This mask defines which mm->def_flags a process can inherit its parent */
421 #define VM_INIT_DEF_MASK VM_NOHUGEPAGE
423 /* This mask is used to clear all the VMA flags used by mlock */
424 #define VM_LOCKED_CLEAR_MASK (~(VM_LOCKED | VM_LOCKONFAULT))
426 /* Arch-specific flags to clear when updating VM flags on protection change */
427 #ifndef VM_ARCH_CLEAR
428 # define VM_ARCH_CLEAR VM_NONE
430 #define VM_FLAGS_CLEAR (ARCH_VM_PKEY_FLAGS | VM_ARCH_CLEAR)
433 * mapping from the currently active vm_flags protection bits (the
434 * low four bits) to a page protection mask..
436 extern pgprot_t protection_map[16];
439 * enum fault_flag - Fault flag definitions.
440 * @FAULT_FLAG_WRITE: Fault was a write fault.
441 * @FAULT_FLAG_MKWRITE: Fault was mkwrite of existing PTE.
442 * @FAULT_FLAG_ALLOW_RETRY: Allow to retry the fault if blocked.
443 * @FAULT_FLAG_RETRY_NOWAIT: Don't drop mmap_lock and wait when retrying.
444 * @FAULT_FLAG_KILLABLE: The fault task is in SIGKILL killable region.
445 * @FAULT_FLAG_TRIED: The fault has been tried once.
446 * @FAULT_FLAG_USER: The fault originated in userspace.
447 * @FAULT_FLAG_REMOTE: The fault is not for current task/mm.
448 * @FAULT_FLAG_INSTRUCTION: The fault was during an instruction fetch.
449 * @FAULT_FLAG_INTERRUPTIBLE: The fault can be interrupted by non-fatal signals.
451 * About @FAULT_FLAG_ALLOW_RETRY and @FAULT_FLAG_TRIED: we can specify
452 * whether we would allow page faults to retry by specifying these two
453 * fault flags correctly. Currently there can be three legal combinations:
455 * (a) ALLOW_RETRY and !TRIED: this means the page fault allows retry, and
456 * this is the first try
458 * (b) ALLOW_RETRY and TRIED: this means the page fault allows retry, and
459 * we've already tried at least once
461 * (c) !ALLOW_RETRY and !TRIED: this means the page fault does not allow retry
463 * The unlisted combination (!ALLOW_RETRY && TRIED) is illegal and should never
464 * be used. Note that page faults can be allowed to retry for multiple times,
465 * in which case we'll have an initial fault with flags (a) then later on
466 * continuous faults with flags (b). We should always try to detect pending
467 * signals before a retry to make sure the continuous page faults can still be
468 * interrupted if necessary.
471 FAULT_FLAG_WRITE = 1 << 0,
472 FAULT_FLAG_MKWRITE = 1 << 1,
473 FAULT_FLAG_ALLOW_RETRY = 1 << 2,
474 FAULT_FLAG_RETRY_NOWAIT = 1 << 3,
475 FAULT_FLAG_KILLABLE = 1 << 4,
476 FAULT_FLAG_TRIED = 1 << 5,
477 FAULT_FLAG_USER = 1 << 6,
478 FAULT_FLAG_REMOTE = 1 << 7,
479 FAULT_FLAG_INSTRUCTION = 1 << 8,
480 FAULT_FLAG_INTERRUPTIBLE = 1 << 9,
484 * The default fault flags that should be used by most of the
485 * arch-specific page fault handlers.
487 #define FAULT_FLAG_DEFAULT (FAULT_FLAG_ALLOW_RETRY | \
488 FAULT_FLAG_KILLABLE | \
489 FAULT_FLAG_INTERRUPTIBLE)
492 * fault_flag_allow_retry_first - check ALLOW_RETRY the first time
493 * @flags: Fault flags.
495 * This is mostly used for places where we want to try to avoid taking
496 * the mmap_lock for too long a time when waiting for another condition
497 * to change, in which case we can try to be polite to release the
498 * mmap_lock in the first round to avoid potential starvation of other
499 * processes that would also want the mmap_lock.
501 * Return: true if the page fault allows retry and this is the first
502 * attempt of the fault handling; false otherwise.
504 static inline bool fault_flag_allow_retry_first(enum fault_flag flags)
506 return (flags & FAULT_FLAG_ALLOW_RETRY) &&
507 (!(flags & FAULT_FLAG_TRIED));
510 #define FAULT_FLAG_TRACE \
511 { FAULT_FLAG_WRITE, "WRITE" }, \
512 { FAULT_FLAG_MKWRITE, "MKWRITE" }, \
513 { FAULT_FLAG_ALLOW_RETRY, "ALLOW_RETRY" }, \
514 { FAULT_FLAG_RETRY_NOWAIT, "RETRY_NOWAIT" }, \
515 { FAULT_FLAG_KILLABLE, "KILLABLE" }, \
516 { FAULT_FLAG_TRIED, "TRIED" }, \
517 { FAULT_FLAG_USER, "USER" }, \
518 { FAULT_FLAG_REMOTE, "REMOTE" }, \
519 { FAULT_FLAG_INSTRUCTION, "INSTRUCTION" }, \
520 { FAULT_FLAG_INTERRUPTIBLE, "INTERRUPTIBLE" }
523 * vm_fault is filled by the pagefault handler and passed to the vma's
524 * ->fault function. The vma's ->fault is responsible for returning a bitmask
525 * of VM_FAULT_xxx flags that give details about how the fault was handled.
527 * MM layer fills up gfp_mask for page allocations but fault handler might
528 * alter it if its implementation requires a different allocation context.
530 * pgoff should be used in favour of virtual_address, if possible.
534 struct vm_area_struct *vma; /* Target VMA */
535 gfp_t gfp_mask; /* gfp mask to be used for allocations */
536 pgoff_t pgoff; /* Logical page offset based on vma */
537 unsigned long address; /* Faulting virtual address */
539 enum fault_flag flags; /* FAULT_FLAG_xxx flags
540 * XXX: should really be 'const' */
541 pmd_t *pmd; /* Pointer to pmd entry matching
543 pud_t *pud; /* Pointer to pud entry matching
547 pte_t orig_pte; /* Value of PTE at the time of fault */
548 pmd_t orig_pmd; /* Value of PMD at the time of fault,
549 * used by PMD fault only.
553 struct page *cow_page; /* Page handler may use for COW fault */
554 struct page *page; /* ->fault handlers should return a
555 * page here, unless VM_FAULT_NOPAGE
556 * is set (which is also implied by
559 /* These three entries are valid only while holding ptl lock */
560 pte_t *pte; /* Pointer to pte entry matching
561 * the 'address'. NULL if the page
562 * table hasn't been allocated.
564 spinlock_t *ptl; /* Page table lock.
565 * Protects pte page table if 'pte'
566 * is not NULL, otherwise pmd.
568 pgtable_t prealloc_pte; /* Pre-allocated pte page table.
569 * vm_ops->map_pages() sets up a page
570 * table from atomic context.
571 * do_fault_around() pre-allocates
572 * page table to avoid allocation from
577 /* page entry size for vm->huge_fault() */
578 enum page_entry_size {
585 * These are the virtual MM functions - opening of an area, closing and
586 * unmapping it (needed to keep files on disk up-to-date etc), pointer
587 * to the functions called when a no-page or a wp-page exception occurs.
589 struct vm_operations_struct {
590 void (*open)(struct vm_area_struct * area);
591 void (*close)(struct vm_area_struct * area);
592 /* Called any time before splitting to check if it's allowed */
593 int (*may_split)(struct vm_area_struct *area, unsigned long addr);
594 int (*mremap)(struct vm_area_struct *area);
596 * Called by mprotect() to make driver-specific permission
597 * checks before mprotect() is finalised. The VMA must not
598 * be modified. Returns 0 if eprotect() can proceed.
600 int (*mprotect)(struct vm_area_struct *vma, unsigned long start,
601 unsigned long end, unsigned long newflags);
602 vm_fault_t (*fault)(struct vm_fault *vmf);
603 vm_fault_t (*huge_fault)(struct vm_fault *vmf,
604 enum page_entry_size pe_size);
605 vm_fault_t (*map_pages)(struct vm_fault *vmf,
606 pgoff_t start_pgoff, pgoff_t end_pgoff);
607 unsigned long (*pagesize)(struct vm_area_struct * area);
609 /* notification that a previously read-only page is about to become
610 * writable, if an error is returned it will cause a SIGBUS */
611 vm_fault_t (*page_mkwrite)(struct vm_fault *vmf);
613 /* same as page_mkwrite when using VM_PFNMAP|VM_MIXEDMAP */
614 vm_fault_t (*pfn_mkwrite)(struct vm_fault *vmf);
616 /* called by access_process_vm when get_user_pages() fails, typically
617 * for use by special VMAs. See also generic_access_phys() for a generic
618 * implementation useful for any iomem mapping.
620 int (*access)(struct vm_area_struct *vma, unsigned long addr,
621 void *buf, int len, int write);
623 /* Called by the /proc/PID/maps code to ask the vma whether it
624 * has a special name. Returning non-NULL will also cause this
625 * vma to be dumped unconditionally. */
626 const char *(*name)(struct vm_area_struct *vma);
630 * set_policy() op must add a reference to any non-NULL @new mempolicy
631 * to hold the policy upon return. Caller should pass NULL @new to
632 * remove a policy and fall back to surrounding context--i.e. do not
633 * install a MPOL_DEFAULT policy, nor the task or system default
636 int (*set_policy)(struct vm_area_struct *vma, struct mempolicy *new);
639 * get_policy() op must add reference [mpol_get()] to any policy at
640 * (vma,addr) marked as MPOL_SHARED. The shared policy infrastructure
641 * in mm/mempolicy.c will do this automatically.
642 * get_policy() must NOT add a ref if the policy at (vma,addr) is not
643 * marked as MPOL_SHARED. vma policies are protected by the mmap_lock.
644 * If no [shared/vma] mempolicy exists at the addr, get_policy() op
645 * must return NULL--i.e., do not "fallback" to task or system default
648 struct mempolicy *(*get_policy)(struct vm_area_struct *vma,
652 * Called by vm_normal_page() for special PTEs to find the
653 * page for @addr. This is useful if the default behavior
654 * (using pte_page()) would not find the correct page.
656 struct page *(*find_special_page)(struct vm_area_struct *vma,
660 static inline void vma_init(struct vm_area_struct *vma, struct mm_struct *mm)
662 static const struct vm_operations_struct dummy_vm_ops = {};
664 memset(vma, 0, sizeof(*vma));
666 vma->vm_ops = &dummy_vm_ops;
667 INIT_LIST_HEAD(&vma->anon_vma_chain);
670 static inline void vma_set_anonymous(struct vm_area_struct *vma)
675 static inline bool vma_is_anonymous(struct vm_area_struct *vma)
680 static inline bool vma_is_temporary_stack(struct vm_area_struct *vma)
682 int maybe_stack = vma->vm_flags & (VM_GROWSDOWN | VM_GROWSUP);
687 if ((vma->vm_flags & VM_STACK_INCOMPLETE_SETUP) ==
688 VM_STACK_INCOMPLETE_SETUP)
694 static inline bool vma_is_foreign(struct vm_area_struct *vma)
699 if (current->mm != vma->vm_mm)
705 static inline bool vma_is_accessible(struct vm_area_struct *vma)
707 return vma->vm_flags & VM_ACCESS_FLAGS;
712 * The vma_is_shmem is not inline because it is used only by slow
713 * paths in userfault.
715 bool vma_is_shmem(struct vm_area_struct *vma);
717 static inline bool vma_is_shmem(struct vm_area_struct *vma) { return false; }
720 int vma_is_stack_for_current(struct vm_area_struct *vma);
722 /* flush_tlb_range() takes a vma, not a mm, and can care about flags */
723 #define TLB_FLUSH_VMA(mm,flags) { .vm_mm = (mm), .vm_flags = (flags) }
728 #include <linux/huge_mm.h>
731 * Methods to modify the page usage count.
733 * What counts for a page usage:
734 * - cache mapping (page->mapping)
735 * - private data (page->private)
736 * - page mapped in a task's page tables, each mapping
737 * is counted separately
739 * Also, many kernel routines increase the page count before a critical
740 * routine so they can be sure the page doesn't go away from under them.
744 * Drop a ref, return true if the refcount fell to zero (the page has no users)
746 static inline int put_page_testzero(struct page *page)
748 VM_BUG_ON_PAGE(page_ref_count(page) == 0, page);
749 return page_ref_dec_and_test(page);
753 * Try to grab a ref unless the page has a refcount of zero, return false if
755 * This can be called when MMU is off so it must not access
756 * any of the virtual mappings.
758 static inline int get_page_unless_zero(struct page *page)
760 return page_ref_add_unless(page, 1, 0);
763 extern int page_is_ram(unsigned long pfn);
771 int region_intersects(resource_size_t offset, size_t size, unsigned long flags,
774 /* Support for virtually mapped pages */
775 struct page *vmalloc_to_page(const void *addr);
776 unsigned long vmalloc_to_pfn(const void *addr);
779 * Determine if an address is within the vmalloc range
781 * On nommu, vmalloc/vfree wrap through kmalloc/kfree directly, so there
782 * is no special casing required.
785 #ifndef is_ioremap_addr
786 #define is_ioremap_addr(x) is_vmalloc_addr(x)
790 extern bool is_vmalloc_addr(const void *x);
791 extern int is_vmalloc_or_module_addr(const void *x);
793 static inline bool is_vmalloc_addr(const void *x)
797 static inline int is_vmalloc_or_module_addr(const void *x)
803 extern void *kvmalloc_node(size_t size, gfp_t flags, int node);
804 static inline void *kvmalloc(size_t size, gfp_t flags)
806 return kvmalloc_node(size, flags, NUMA_NO_NODE);
808 static inline void *kvzalloc_node(size_t size, gfp_t flags, int node)
810 return kvmalloc_node(size, flags | __GFP_ZERO, node);
812 static inline void *kvzalloc(size_t size, gfp_t flags)
814 return kvmalloc(size, flags | __GFP_ZERO);
817 static inline void *kvmalloc_array(size_t n, size_t size, gfp_t flags)
821 if (unlikely(check_mul_overflow(n, size, &bytes)))
824 return kvmalloc(bytes, flags);
827 static inline void *kvcalloc(size_t n, size_t size, gfp_t flags)
829 return kvmalloc_array(n, size, flags | __GFP_ZERO);
832 extern void kvfree(const void *addr);
833 extern void kvfree_sensitive(const void *addr, size_t len);
835 static inline int head_compound_mapcount(struct page *head)
837 return atomic_read(compound_mapcount_ptr(head)) + 1;
841 * Mapcount of compound page as a whole, does not include mapped sub-pages.
843 * Must be called only for compound pages or any their tail sub-pages.
845 static inline int compound_mapcount(struct page *page)
847 VM_BUG_ON_PAGE(!PageCompound(page), page);
848 page = compound_head(page);
849 return head_compound_mapcount(page);
853 * The atomic page->_mapcount, starts from -1: so that transitions
854 * both from it and to it can be tracked, using atomic_inc_and_test
855 * and atomic_add_negative(-1).
857 static inline void page_mapcount_reset(struct page *page)
859 atomic_set(&(page)->_mapcount, -1);
862 int __page_mapcount(struct page *page);
865 * Mapcount of 0-order page; when compound sub-page, includes
866 * compound_mapcount().
868 * Result is undefined for pages which cannot be mapped into userspace.
869 * For example SLAB or special types of pages. See function page_has_type().
870 * They use this place in struct page differently.
872 static inline int page_mapcount(struct page *page)
874 if (unlikely(PageCompound(page)))
875 return __page_mapcount(page);
876 return atomic_read(&page->_mapcount) + 1;
879 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
880 int total_mapcount(struct page *page);
881 int page_trans_huge_mapcount(struct page *page, int *total_mapcount);
883 static inline int total_mapcount(struct page *page)
885 return page_mapcount(page);
887 static inline int page_trans_huge_mapcount(struct page *page,
890 int mapcount = page_mapcount(page);
892 *total_mapcount = mapcount;
897 static inline struct page *virt_to_head_page(const void *x)
899 struct page *page = virt_to_page(x);
901 return compound_head(page);
904 void __put_page(struct page *page);
906 void put_pages_list(struct list_head *pages);
908 void split_page(struct page *page, unsigned int order);
909 void copy_huge_page(struct page *dst, struct page *src);
912 * Compound pages have a destructor function. Provide a
913 * prototype for that function and accessor functions.
914 * These are _only_ valid on the head of a compound page.
916 typedef void compound_page_dtor(struct page *);
918 /* Keep the enum in sync with compound_page_dtors array in mm/page_alloc.c */
919 enum compound_dtor_id {
922 #ifdef CONFIG_HUGETLB_PAGE
925 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
930 extern compound_page_dtor * const compound_page_dtors[NR_COMPOUND_DTORS];
932 static inline void set_compound_page_dtor(struct page *page,
933 enum compound_dtor_id compound_dtor)
935 VM_BUG_ON_PAGE(compound_dtor >= NR_COMPOUND_DTORS, page);
936 page[1].compound_dtor = compound_dtor;
939 static inline void destroy_compound_page(struct page *page)
941 VM_BUG_ON_PAGE(page[1].compound_dtor >= NR_COMPOUND_DTORS, page);
942 compound_page_dtors[page[1].compound_dtor](page);
945 static inline unsigned int compound_order(struct page *page)
949 return page[1].compound_order;
952 static inline bool hpage_pincount_available(struct page *page)
955 * Can the page->hpage_pinned_refcount field be used? That field is in
956 * the 3rd page of the compound page, so the smallest (2-page) compound
957 * pages cannot support it.
959 page = compound_head(page);
960 return PageCompound(page) && compound_order(page) > 1;
963 static inline int head_compound_pincount(struct page *head)
965 return atomic_read(compound_pincount_ptr(head));
968 static inline int compound_pincount(struct page *page)
970 VM_BUG_ON_PAGE(!hpage_pincount_available(page), page);
971 page = compound_head(page);
972 return head_compound_pincount(page);
975 static inline void set_compound_order(struct page *page, unsigned int order)
977 page[1].compound_order = order;
978 page[1].compound_nr = 1U << order;
981 /* Returns the number of pages in this potentially compound page. */
982 static inline unsigned long compound_nr(struct page *page)
986 return page[1].compound_nr;
989 /* Returns the number of bytes in this potentially compound page. */
990 static inline unsigned long page_size(struct page *page)
992 return PAGE_SIZE << compound_order(page);
995 /* Returns the number of bits needed for the number of bytes in a page */
996 static inline unsigned int page_shift(struct page *page)
998 return PAGE_SHIFT + compound_order(page);
1001 void free_compound_page(struct page *page);
1005 * Do pte_mkwrite, but only if the vma says VM_WRITE. We do this when
1006 * servicing faults for write access. In the normal case, do always want
1007 * pte_mkwrite. But get_user_pages can cause write faults for mappings
1008 * that do not have writing enabled, when used by access_process_vm.
1010 static inline pte_t maybe_mkwrite(pte_t pte, struct vm_area_struct *vma)
1012 if (likely(vma->vm_flags & VM_WRITE))
1013 pte = pte_mkwrite(pte);
1017 vm_fault_t do_set_pmd(struct vm_fault *vmf, struct page *page);
1018 void do_set_pte(struct vm_fault *vmf, struct page *page, unsigned long addr);
1020 vm_fault_t finish_fault(struct vm_fault *vmf);
1021 vm_fault_t finish_mkwrite_fault(struct vm_fault *vmf);
1025 * Multiple processes may "see" the same page. E.g. for untouched
1026 * mappings of /dev/null, all processes see the same page full of
1027 * zeroes, and text pages of executables and shared libraries have
1028 * only one copy in memory, at most, normally.
1030 * For the non-reserved pages, page_count(page) denotes a reference count.
1031 * page_count() == 0 means the page is free. page->lru is then used for
1032 * freelist management in the buddy allocator.
1033 * page_count() > 0 means the page has been allocated.
1035 * Pages are allocated by the slab allocator in order to provide memory
1036 * to kmalloc and kmem_cache_alloc. In this case, the management of the
1037 * page, and the fields in 'struct page' are the responsibility of mm/slab.c
1038 * unless a particular usage is carefully commented. (the responsibility of
1039 * freeing the kmalloc memory is the caller's, of course).
1041 * A page may be used by anyone else who does a __get_free_page().
1042 * In this case, page_count still tracks the references, and should only
1043 * be used through the normal accessor functions. The top bits of page->flags
1044 * and page->virtual store page management information, but all other fields
1045 * are unused and could be used privately, carefully. The management of this
1046 * page is the responsibility of the one who allocated it, and those who have
1047 * subsequently been given references to it.
1049 * The other pages (we may call them "pagecache pages") are completely
1050 * managed by the Linux memory manager: I/O, buffers, swapping etc.
1051 * The following discussion applies only to them.
1053 * A pagecache page contains an opaque `private' member, which belongs to the
1054 * page's address_space. Usually, this is the address of a circular list of
1055 * the page's disk buffers. PG_private must be set to tell the VM to call
1056 * into the filesystem to release these pages.
1058 * A page may belong to an inode's memory mapping. In this case, page->mapping
1059 * is the pointer to the inode, and page->index is the file offset of the page,
1060 * in units of PAGE_SIZE.
1062 * If pagecache pages are not associated with an inode, they are said to be
1063 * anonymous pages. These may become associated with the swapcache, and in that
1064 * case PG_swapcache is set, and page->private is an offset into the swapcache.
1066 * In either case (swapcache or inode backed), the pagecache itself holds one
1067 * reference to the page. Setting PG_private should also increment the
1068 * refcount. The each user mapping also has a reference to the page.
1070 * The pagecache pages are stored in a per-mapping radix tree, which is
1071 * rooted at mapping->i_pages, and indexed by offset.
1072 * Where 2.4 and early 2.6 kernels kept dirty/clean pages in per-address_space
1073 * lists, we instead now tag pages as dirty/writeback in the radix tree.
1075 * All pagecache pages may be subject to I/O:
1076 * - inode pages may need to be read from disk,
1077 * - inode pages which have been modified and are MAP_SHARED may need
1078 * to be written back to the inode on disk,
1079 * - anonymous pages (including MAP_PRIVATE file mappings) which have been
1080 * modified may need to be swapped out to swap space and (later) to be read
1085 * The zone field is never updated after free_area_init_core()
1086 * sets it, so none of the operations on it need to be atomic.
1089 /* Page flags: | [SECTION] | [NODE] | ZONE | [LAST_CPUPID] | ... | FLAGS | */
1090 #define SECTIONS_PGOFF ((sizeof(unsigned long)*8) - SECTIONS_WIDTH)
1091 #define NODES_PGOFF (SECTIONS_PGOFF - NODES_WIDTH)
1092 #define ZONES_PGOFF (NODES_PGOFF - ZONES_WIDTH)
1093 #define LAST_CPUPID_PGOFF (ZONES_PGOFF - LAST_CPUPID_WIDTH)
1094 #define KASAN_TAG_PGOFF (LAST_CPUPID_PGOFF - KASAN_TAG_WIDTH)
1097 * Define the bit shifts to access each section. For non-existent
1098 * sections we define the shift as 0; that plus a 0 mask ensures
1099 * the compiler will optimise away reference to them.
1101 #define SECTIONS_PGSHIFT (SECTIONS_PGOFF * (SECTIONS_WIDTH != 0))
1102 #define NODES_PGSHIFT (NODES_PGOFF * (NODES_WIDTH != 0))
1103 #define ZONES_PGSHIFT (ZONES_PGOFF * (ZONES_WIDTH != 0))
1104 #define LAST_CPUPID_PGSHIFT (LAST_CPUPID_PGOFF * (LAST_CPUPID_WIDTH != 0))
1105 #define KASAN_TAG_PGSHIFT (KASAN_TAG_PGOFF * (KASAN_TAG_WIDTH != 0))
1107 /* NODE:ZONE or SECTION:ZONE is used to ID a zone for the buddy allocator */
1108 #ifdef NODE_NOT_IN_PAGE_FLAGS
1109 #define ZONEID_SHIFT (SECTIONS_SHIFT + ZONES_SHIFT)
1110 #define ZONEID_PGOFF ((SECTIONS_PGOFF < ZONES_PGOFF)? \
1111 SECTIONS_PGOFF : ZONES_PGOFF)
1113 #define ZONEID_SHIFT (NODES_SHIFT + ZONES_SHIFT)
1114 #define ZONEID_PGOFF ((NODES_PGOFF < ZONES_PGOFF)? \
1115 NODES_PGOFF : ZONES_PGOFF)
1118 #define ZONEID_PGSHIFT (ZONEID_PGOFF * (ZONEID_SHIFT != 0))
1120 #define ZONES_MASK ((1UL << ZONES_WIDTH) - 1)
1121 #define NODES_MASK ((1UL << NODES_WIDTH) - 1)
1122 #define SECTIONS_MASK ((1UL << SECTIONS_WIDTH) - 1)
1123 #define LAST_CPUPID_MASK ((1UL << LAST_CPUPID_SHIFT) - 1)
1124 #define KASAN_TAG_MASK ((1UL << KASAN_TAG_WIDTH) - 1)
1125 #define ZONEID_MASK ((1UL << ZONEID_SHIFT) - 1)
1127 static inline enum zone_type page_zonenum(const struct page *page)
1129 ASSERT_EXCLUSIVE_BITS(page->flags, ZONES_MASK << ZONES_PGSHIFT);
1130 return (page->flags >> ZONES_PGSHIFT) & ZONES_MASK;
1133 #ifdef CONFIG_ZONE_DEVICE
1134 static inline bool is_zone_device_page(const struct page *page)
1136 return page_zonenum(page) == ZONE_DEVICE;
1138 extern void memmap_init_zone_device(struct zone *, unsigned long,
1139 unsigned long, struct dev_pagemap *);
1141 static inline bool is_zone_device_page(const struct page *page)
1147 static inline bool is_zone_movable_page(const struct page *page)
1149 return page_zonenum(page) == ZONE_MOVABLE;
1152 #ifdef CONFIG_DEV_PAGEMAP_OPS
1153 void free_devmap_managed_page(struct page *page);
1154 DECLARE_STATIC_KEY_FALSE(devmap_managed_key);
1156 static inline bool page_is_devmap_managed(struct page *page)
1158 if (!static_branch_unlikely(&devmap_managed_key))
1160 if (!is_zone_device_page(page))
1162 switch (page->pgmap->type) {
1163 case MEMORY_DEVICE_PRIVATE:
1164 case MEMORY_DEVICE_FS_DAX:
1172 void put_devmap_managed_page(struct page *page);
1174 #else /* CONFIG_DEV_PAGEMAP_OPS */
1175 static inline bool page_is_devmap_managed(struct page *page)
1180 static inline void put_devmap_managed_page(struct page *page)
1183 #endif /* CONFIG_DEV_PAGEMAP_OPS */
1185 static inline bool is_device_private_page(const struct page *page)
1187 return IS_ENABLED(CONFIG_DEV_PAGEMAP_OPS) &&
1188 IS_ENABLED(CONFIG_DEVICE_PRIVATE) &&
1189 is_zone_device_page(page) &&
1190 page->pgmap->type == MEMORY_DEVICE_PRIVATE;
1193 static inline bool is_pci_p2pdma_page(const struct page *page)
1195 return IS_ENABLED(CONFIG_DEV_PAGEMAP_OPS) &&
1196 IS_ENABLED(CONFIG_PCI_P2PDMA) &&
1197 is_zone_device_page(page) &&
1198 page->pgmap->type == MEMORY_DEVICE_PCI_P2PDMA;
1201 /* 127: arbitrary random number, small enough to assemble well */
1202 #define page_ref_zero_or_close_to_overflow(page) \
1203 ((unsigned int) page_ref_count(page) + 127u <= 127u)
1205 static inline void get_page(struct page *page)
1207 page = compound_head(page);
1209 * Getting a normal page or the head of a compound page
1210 * requires to already have an elevated page->_refcount.
1212 VM_BUG_ON_PAGE(page_ref_zero_or_close_to_overflow(page), page);
1216 bool __must_check try_grab_page(struct page *page, unsigned int flags);
1217 __maybe_unused struct page *try_grab_compound_head(struct page *page, int refs,
1218 unsigned int flags);
1221 static inline __must_check bool try_get_page(struct page *page)
1223 page = compound_head(page);
1224 if (WARN_ON_ONCE(page_ref_count(page) <= 0))
1230 static inline void put_page(struct page *page)
1232 page = compound_head(page);
1235 * For devmap managed pages we need to catch refcount transition from
1236 * 2 to 1, when refcount reach one it means the page is free and we
1237 * need to inform the device driver through callback. See
1238 * include/linux/memremap.h and HMM for details.
1240 if (page_is_devmap_managed(page)) {
1241 put_devmap_managed_page(page);
1245 if (put_page_testzero(page))
1250 * GUP_PIN_COUNTING_BIAS, and the associated functions that use it, overload
1251 * the page's refcount so that two separate items are tracked: the original page
1252 * reference count, and also a new count of how many pin_user_pages() calls were
1253 * made against the page. ("gup-pinned" is another term for the latter).
1255 * With this scheme, pin_user_pages() becomes special: such pages are marked as
1256 * distinct from normal pages. As such, the unpin_user_page() call (and its
1257 * variants) must be used in order to release gup-pinned pages.
1261 * By making GUP_PIN_COUNTING_BIAS a power of two, debugging of page reference
1262 * counts with respect to pin_user_pages() and unpin_user_page() becomes
1263 * simpler, due to the fact that adding an even power of two to the page
1264 * refcount has the effect of using only the upper N bits, for the code that
1265 * counts up using the bias value. This means that the lower bits are left for
1266 * the exclusive use of the original code that increments and decrements by one
1267 * (or at least, by much smaller values than the bias value).
1269 * Of course, once the lower bits overflow into the upper bits (and this is
1270 * OK, because subtraction recovers the original values), then visual inspection
1271 * no longer suffices to directly view the separate counts. However, for normal
1272 * applications that don't have huge page reference counts, this won't be an
1275 * Locking: the lockless algorithm described in page_cache_get_speculative()
1276 * and page_cache_gup_pin_speculative() provides safe operation for
1277 * get_user_pages and page_mkclean and other calls that race to set up page
1280 #define GUP_PIN_COUNTING_BIAS (1U << 10)
1282 void unpin_user_page(struct page *page);
1283 void unpin_user_pages_dirty_lock(struct page **pages, unsigned long npages,
1285 void unpin_user_page_range_dirty_lock(struct page *page, unsigned long npages,
1287 void unpin_user_pages(struct page **pages, unsigned long npages);
1290 * page_maybe_dma_pinned - Report if a page is pinned for DMA.
1293 * This function checks if a page has been pinned via a call to
1294 * a function in the pin_user_pages() family.
1296 * For non-huge pages, the return value is partially fuzzy: false is not fuzzy,
1297 * because it means "definitely not pinned for DMA", but true means "probably
1298 * pinned for DMA, but possibly a false positive due to having at least
1299 * GUP_PIN_COUNTING_BIAS worth of normal page references".
1301 * False positives are OK, because: a) it's unlikely for a page to get that many
1302 * refcounts, and b) all the callers of this routine are expected to be able to
1303 * deal gracefully with a false positive.
1305 * For huge pages, the result will be exactly correct. That's because we have
1306 * more tracking data available: the 3rd struct page in the compound page is
1307 * used to track the pincount (instead using of the GUP_PIN_COUNTING_BIAS
1310 * For more information, please see Documentation/core-api/pin_user_pages.rst.
1312 * Return: True, if it is likely that the page has been "dma-pinned".
1313 * False, if the page is definitely not dma-pinned.
1315 static inline bool page_maybe_dma_pinned(struct page *page)
1317 if (hpage_pincount_available(page))
1318 return compound_pincount(page) > 0;
1321 * page_ref_count() is signed. If that refcount overflows, then
1322 * page_ref_count() returns a negative value, and callers will avoid
1323 * further incrementing the refcount.
1325 * Here, for that overflow case, use the signed bit to count a little
1326 * bit higher via unsigned math, and thus still get an accurate result.
1328 return ((unsigned int)page_ref_count(compound_head(page))) >=
1329 GUP_PIN_COUNTING_BIAS;
1332 static inline bool is_cow_mapping(vm_flags_t flags)
1334 return (flags & (VM_SHARED | VM_MAYWRITE)) == VM_MAYWRITE;
1338 * This should most likely only be called during fork() to see whether we
1339 * should break the cow immediately for a page on the src mm.
1341 static inline bool page_needs_cow_for_dma(struct vm_area_struct *vma,
1344 if (!is_cow_mapping(vma->vm_flags))
1347 if (!test_bit(MMF_HAS_PINNED, &vma->vm_mm->flags))
1350 return page_maybe_dma_pinned(page);
1353 #if defined(CONFIG_SPARSEMEM) && !defined(CONFIG_SPARSEMEM_VMEMMAP)
1354 #define SECTION_IN_PAGE_FLAGS
1358 * The identification function is mainly used by the buddy allocator for
1359 * determining if two pages could be buddies. We are not really identifying
1360 * the zone since we could be using the section number id if we do not have
1361 * node id available in page flags.
1362 * We only guarantee that it will return the same value for two combinable
1365 static inline int page_zone_id(struct page *page)
1367 return (page->flags >> ZONEID_PGSHIFT) & ZONEID_MASK;
1370 #ifdef NODE_NOT_IN_PAGE_FLAGS
1371 extern int page_to_nid(const struct page *page);
1373 static inline int page_to_nid(const struct page *page)
1375 struct page *p = (struct page *)page;
1377 return (PF_POISONED_CHECK(p)->flags >> NODES_PGSHIFT) & NODES_MASK;
1381 #ifdef CONFIG_NUMA_BALANCING
1382 static inline int cpu_pid_to_cpupid(int cpu, int pid)
1384 return ((cpu & LAST__CPU_MASK) << LAST__PID_SHIFT) | (pid & LAST__PID_MASK);
1387 static inline int cpupid_to_pid(int cpupid)
1389 return cpupid & LAST__PID_MASK;
1392 static inline int cpupid_to_cpu(int cpupid)
1394 return (cpupid >> LAST__PID_SHIFT) & LAST__CPU_MASK;
1397 static inline int cpupid_to_nid(int cpupid)
1399 return cpu_to_node(cpupid_to_cpu(cpupid));
1402 static inline bool cpupid_pid_unset(int cpupid)
1404 return cpupid_to_pid(cpupid) == (-1 & LAST__PID_MASK);
1407 static inline bool cpupid_cpu_unset(int cpupid)
1409 return cpupid_to_cpu(cpupid) == (-1 & LAST__CPU_MASK);
1412 static inline bool __cpupid_match_pid(pid_t task_pid, int cpupid)
1414 return (task_pid & LAST__PID_MASK) == cpupid_to_pid(cpupid);
1417 #define cpupid_match_pid(task, cpupid) __cpupid_match_pid(task->pid, cpupid)
1418 #ifdef LAST_CPUPID_NOT_IN_PAGE_FLAGS
1419 static inline int page_cpupid_xchg_last(struct page *page, int cpupid)
1421 return xchg(&page->_last_cpupid, cpupid & LAST_CPUPID_MASK);
1424 static inline int page_cpupid_last(struct page *page)
1426 return page->_last_cpupid;
1428 static inline void page_cpupid_reset_last(struct page *page)
1430 page->_last_cpupid = -1 & LAST_CPUPID_MASK;
1433 static inline int page_cpupid_last(struct page *page)
1435 return (page->flags >> LAST_CPUPID_PGSHIFT) & LAST_CPUPID_MASK;
1438 extern int page_cpupid_xchg_last(struct page *page, int cpupid);
1440 static inline void page_cpupid_reset_last(struct page *page)
1442 page->flags |= LAST_CPUPID_MASK << LAST_CPUPID_PGSHIFT;
1444 #endif /* LAST_CPUPID_NOT_IN_PAGE_FLAGS */
1445 #else /* !CONFIG_NUMA_BALANCING */
1446 static inline int page_cpupid_xchg_last(struct page *page, int cpupid)
1448 return page_to_nid(page); /* XXX */
1451 static inline int page_cpupid_last(struct page *page)
1453 return page_to_nid(page); /* XXX */
1456 static inline int cpupid_to_nid(int cpupid)
1461 static inline int cpupid_to_pid(int cpupid)
1466 static inline int cpupid_to_cpu(int cpupid)
1471 static inline int cpu_pid_to_cpupid(int nid, int pid)
1476 static inline bool cpupid_pid_unset(int cpupid)
1481 static inline void page_cpupid_reset_last(struct page *page)
1485 static inline bool cpupid_match_pid(struct task_struct *task, int cpupid)
1489 #endif /* CONFIG_NUMA_BALANCING */
1491 #if defined(CONFIG_KASAN_SW_TAGS) || defined(CONFIG_KASAN_HW_TAGS)
1494 * KASAN per-page tags are stored xor'ed with 0xff. This allows to avoid
1495 * setting tags for all pages to native kernel tag value 0xff, as the default
1496 * value 0x00 maps to 0xff.
1499 static inline u8 page_kasan_tag(const struct page *page)
1503 if (kasan_enabled()) {
1504 tag = (page->flags >> KASAN_TAG_PGSHIFT) & KASAN_TAG_MASK;
1511 static inline void page_kasan_tag_set(struct page *page, u8 tag)
1513 if (kasan_enabled()) {
1515 page->flags &= ~(KASAN_TAG_MASK << KASAN_TAG_PGSHIFT);
1516 page->flags |= (tag & KASAN_TAG_MASK) << KASAN_TAG_PGSHIFT;
1520 static inline void page_kasan_tag_reset(struct page *page)
1522 if (kasan_enabled())
1523 page_kasan_tag_set(page, 0xff);
1526 #else /* CONFIG_KASAN_SW_TAGS || CONFIG_KASAN_HW_TAGS */
1528 static inline u8 page_kasan_tag(const struct page *page)
1533 static inline void page_kasan_tag_set(struct page *page, u8 tag) { }
1534 static inline void page_kasan_tag_reset(struct page *page) { }
1536 #endif /* CONFIG_KASAN_SW_TAGS || CONFIG_KASAN_HW_TAGS */
1538 static inline struct zone *page_zone(const struct page *page)
1540 return &NODE_DATA(page_to_nid(page))->node_zones[page_zonenum(page)];
1543 static inline pg_data_t *page_pgdat(const struct page *page)
1545 return NODE_DATA(page_to_nid(page));
1548 #ifdef SECTION_IN_PAGE_FLAGS
1549 static inline void set_page_section(struct page *page, unsigned long section)
1551 page->flags &= ~(SECTIONS_MASK << SECTIONS_PGSHIFT);
1552 page->flags |= (section & SECTIONS_MASK) << SECTIONS_PGSHIFT;
1555 static inline unsigned long page_to_section(const struct page *page)
1557 return (page->flags >> SECTIONS_PGSHIFT) & SECTIONS_MASK;
1561 /* MIGRATE_CMA and ZONE_MOVABLE do not allow pin pages */
1562 #ifdef CONFIG_MIGRATION
1563 static inline bool is_pinnable_page(struct page *page)
1565 return !(is_zone_movable_page(page) || is_migrate_cma_page(page)) ||
1566 is_zero_pfn(page_to_pfn(page));
1569 static inline bool is_pinnable_page(struct page *page)
1575 static inline void set_page_zone(struct page *page, enum zone_type zone)
1577 page->flags &= ~(ZONES_MASK << ZONES_PGSHIFT);
1578 page->flags |= (zone & ZONES_MASK) << ZONES_PGSHIFT;
1581 static inline void set_page_node(struct page *page, unsigned long node)
1583 page->flags &= ~(NODES_MASK << NODES_PGSHIFT);
1584 page->flags |= (node & NODES_MASK) << NODES_PGSHIFT;
1587 static inline void set_page_links(struct page *page, enum zone_type zone,
1588 unsigned long node, unsigned long pfn)
1590 set_page_zone(page, zone);
1591 set_page_node(page, node);
1592 #ifdef SECTION_IN_PAGE_FLAGS
1593 set_page_section(page, pfn_to_section_nr(pfn));
1598 * Some inline functions in vmstat.h depend on page_zone()
1600 #include <linux/vmstat.h>
1602 static __always_inline void *lowmem_page_address(const struct page *page)
1604 return page_to_virt(page);
1607 #if defined(CONFIG_HIGHMEM) && !defined(WANT_PAGE_VIRTUAL)
1608 #define HASHED_PAGE_VIRTUAL
1611 #if defined(WANT_PAGE_VIRTUAL)
1612 static inline void *page_address(const struct page *page)
1614 return page->virtual;
1616 static inline void set_page_address(struct page *page, void *address)
1618 page->virtual = address;
1620 #define page_address_init() do { } while(0)
1623 #if defined(HASHED_PAGE_VIRTUAL)
1624 void *page_address(const struct page *page);
1625 void set_page_address(struct page *page, void *virtual);
1626 void page_address_init(void);
1629 #if !defined(HASHED_PAGE_VIRTUAL) && !defined(WANT_PAGE_VIRTUAL)
1630 #define page_address(page) lowmem_page_address(page)
1631 #define set_page_address(page, address) do { } while(0)
1632 #define page_address_init() do { } while(0)
1635 extern void *page_rmapping(struct page *page);
1636 extern struct anon_vma *page_anon_vma(struct page *page);
1637 extern struct address_space *page_mapping(struct page *page);
1639 extern struct address_space *__page_file_mapping(struct page *);
1642 struct address_space *page_file_mapping(struct page *page)
1644 if (unlikely(PageSwapCache(page)))
1645 return __page_file_mapping(page);
1647 return page->mapping;
1650 extern pgoff_t __page_file_index(struct page *page);
1653 * Return the pagecache index of the passed page. Regular pagecache pages
1654 * use ->index whereas swapcache pages use swp_offset(->private)
1656 static inline pgoff_t page_index(struct page *page)
1658 if (unlikely(PageSwapCache(page)))
1659 return __page_file_index(page);
1663 bool page_mapped(struct page *page);
1664 struct address_space *page_mapping(struct page *page);
1667 * Return true only if the page has been allocated with
1668 * ALLOC_NO_WATERMARKS and the low watermark was not
1669 * met implying that the system is under some pressure.
1671 static inline bool page_is_pfmemalloc(const struct page *page)
1674 * lru.next has bit 1 set if the page is allocated from the
1675 * pfmemalloc reserves. Callers may simply overwrite it if
1676 * they do not need to preserve that information.
1678 return (uintptr_t)page->lru.next & BIT(1);
1682 * Only to be called by the page allocator on a freshly allocated
1685 static inline void set_page_pfmemalloc(struct page *page)
1687 page->lru.next = (void *)BIT(1);
1690 static inline void clear_page_pfmemalloc(struct page *page)
1692 page->lru.next = NULL;
1696 * Can be called by the pagefault handler when it gets a VM_FAULT_OOM.
1698 extern void pagefault_out_of_memory(void);
1700 #define offset_in_page(p) ((unsigned long)(p) & ~PAGE_MASK)
1701 #define offset_in_thp(page, p) ((unsigned long)(p) & (thp_size(page) - 1))
1704 * Flags passed to show_mem() and show_free_areas() to suppress output in
1707 #define SHOW_MEM_FILTER_NODES (0x0001u) /* disallowed nodes */
1709 extern void show_free_areas(unsigned int flags, nodemask_t *nodemask);
1712 extern bool can_do_mlock(void);
1714 static inline bool can_do_mlock(void) { return false; }
1716 extern int user_shm_lock(size_t, struct ucounts *);
1717 extern void user_shm_unlock(size_t, struct ucounts *);
1720 * Parameter block passed down to zap_pte_range in exceptional cases.
1722 struct zap_details {
1723 struct address_space *check_mapping; /* Check page->mapping if set */
1724 pgoff_t first_index; /* Lowest page->index to unmap */
1725 pgoff_t last_index; /* Highest page->index to unmap */
1726 struct page *single_page; /* Locked page to be unmapped */
1729 struct page *vm_normal_page(struct vm_area_struct *vma, unsigned long addr,
1731 struct page *vm_normal_page_pmd(struct vm_area_struct *vma, unsigned long addr,
1734 void zap_vma_ptes(struct vm_area_struct *vma, unsigned long address,
1735 unsigned long size);
1736 void zap_page_range(struct vm_area_struct *vma, unsigned long address,
1737 unsigned long size);
1738 void unmap_vmas(struct mmu_gather *tlb, struct vm_area_struct *start_vma,
1739 unsigned long start, unsigned long end);
1741 struct mmu_notifier_range;
1743 void free_pgd_range(struct mmu_gather *tlb, unsigned long addr,
1744 unsigned long end, unsigned long floor, unsigned long ceiling);
1746 copy_page_range(struct vm_area_struct *dst_vma, struct vm_area_struct *src_vma);
1747 int follow_invalidate_pte(struct mm_struct *mm, unsigned long address,
1748 struct mmu_notifier_range *range, pte_t **ptepp,
1749 pmd_t **pmdpp, spinlock_t **ptlp);
1750 int follow_pte(struct mm_struct *mm, unsigned long address,
1751 pte_t **ptepp, spinlock_t **ptlp);
1752 int follow_pfn(struct vm_area_struct *vma, unsigned long address,
1753 unsigned long *pfn);
1754 int follow_phys(struct vm_area_struct *vma, unsigned long address,
1755 unsigned int flags, unsigned long *prot, resource_size_t *phys);
1756 int generic_access_phys(struct vm_area_struct *vma, unsigned long addr,
1757 void *buf, int len, int write);
1759 extern void truncate_pagecache(struct inode *inode, loff_t new);
1760 extern void truncate_setsize(struct inode *inode, loff_t newsize);
1761 void pagecache_isize_extended(struct inode *inode, loff_t from, loff_t to);
1762 void truncate_pagecache_range(struct inode *inode, loff_t offset, loff_t end);
1763 int truncate_inode_page(struct address_space *mapping, struct page *page);
1764 int generic_error_remove_page(struct address_space *mapping, struct page *page);
1765 int invalidate_inode_page(struct page *page);
1768 extern vm_fault_t handle_mm_fault(struct vm_area_struct *vma,
1769 unsigned long address, unsigned int flags,
1770 struct pt_regs *regs);
1771 extern int fixup_user_fault(struct mm_struct *mm,
1772 unsigned long address, unsigned int fault_flags,
1774 void unmap_mapping_page(struct page *page);
1775 void unmap_mapping_pages(struct address_space *mapping,
1776 pgoff_t start, pgoff_t nr, bool even_cows);
1777 void unmap_mapping_range(struct address_space *mapping,
1778 loff_t const holebegin, loff_t const holelen, int even_cows);
1780 static inline vm_fault_t handle_mm_fault(struct vm_area_struct *vma,
1781 unsigned long address, unsigned int flags,
1782 struct pt_regs *regs)
1784 /* should never happen if there's no MMU */
1786 return VM_FAULT_SIGBUS;
1788 static inline int fixup_user_fault(struct mm_struct *mm, unsigned long address,
1789 unsigned int fault_flags, bool *unlocked)
1791 /* should never happen if there's no MMU */
1795 static inline void unmap_mapping_page(struct page *page) { }
1796 static inline void unmap_mapping_pages(struct address_space *mapping,
1797 pgoff_t start, pgoff_t nr, bool even_cows) { }
1798 static inline void unmap_mapping_range(struct address_space *mapping,
1799 loff_t const holebegin, loff_t const holelen, int even_cows) { }
1802 static inline void unmap_shared_mapping_range(struct address_space *mapping,
1803 loff_t const holebegin, loff_t const holelen)
1805 unmap_mapping_range(mapping, holebegin, holelen, 0);
1808 extern int access_process_vm(struct task_struct *tsk, unsigned long addr,
1809 void *buf, int len, unsigned int gup_flags);
1810 extern int access_remote_vm(struct mm_struct *mm, unsigned long addr,
1811 void *buf, int len, unsigned int gup_flags);
1812 extern int __access_remote_vm(struct mm_struct *mm, unsigned long addr,
1813 void *buf, int len, unsigned int gup_flags);
1815 long get_user_pages_remote(struct mm_struct *mm,
1816 unsigned long start, unsigned long nr_pages,
1817 unsigned int gup_flags, struct page **pages,
1818 struct vm_area_struct **vmas, int *locked);
1819 long pin_user_pages_remote(struct mm_struct *mm,
1820 unsigned long start, unsigned long nr_pages,
1821 unsigned int gup_flags, struct page **pages,
1822 struct vm_area_struct **vmas, int *locked);
1823 long get_user_pages(unsigned long start, unsigned long nr_pages,
1824 unsigned int gup_flags, struct page **pages,
1825 struct vm_area_struct **vmas);
1826 long pin_user_pages(unsigned long start, unsigned long nr_pages,
1827 unsigned int gup_flags, struct page **pages,
1828 struct vm_area_struct **vmas);
1829 long get_user_pages_locked(unsigned long start, unsigned long nr_pages,
1830 unsigned int gup_flags, struct page **pages, int *locked);
1831 long pin_user_pages_locked(unsigned long start, unsigned long nr_pages,
1832 unsigned int gup_flags, struct page **pages, int *locked);
1833 long get_user_pages_unlocked(unsigned long start, unsigned long nr_pages,
1834 struct page **pages, unsigned int gup_flags);
1835 long pin_user_pages_unlocked(unsigned long start, unsigned long nr_pages,
1836 struct page **pages, unsigned int gup_flags);
1838 int get_user_pages_fast(unsigned long start, int nr_pages,
1839 unsigned int gup_flags, struct page **pages);
1840 int pin_user_pages_fast(unsigned long start, int nr_pages,
1841 unsigned int gup_flags, struct page **pages);
1843 int account_locked_vm(struct mm_struct *mm, unsigned long pages, bool inc);
1844 int __account_locked_vm(struct mm_struct *mm, unsigned long pages, bool inc,
1845 struct task_struct *task, bool bypass_rlim);
1848 int get_kernel_pages(const struct kvec *iov, int nr_pages, int write,
1849 struct page **pages);
1850 int get_kernel_page(unsigned long start, int write, struct page **pages);
1851 struct page *get_dump_page(unsigned long addr);
1853 extern int try_to_release_page(struct page * page, gfp_t gfp_mask);
1854 extern void do_invalidatepage(struct page *page, unsigned int offset,
1855 unsigned int length);
1857 int redirty_page_for_writepage(struct writeback_control *wbc,
1859 void account_page_cleaned(struct page *page, struct address_space *mapping,
1860 struct bdi_writeback *wb);
1861 int set_page_dirty(struct page *page);
1862 int set_page_dirty_lock(struct page *page);
1863 void __cancel_dirty_page(struct page *page);
1864 static inline void cancel_dirty_page(struct page *page)
1866 /* Avoid atomic ops, locking, etc. when not actually needed. */
1867 if (PageDirty(page))
1868 __cancel_dirty_page(page);
1870 int clear_page_dirty_for_io(struct page *page);
1872 int get_cmdline(struct task_struct *task, char *buffer, int buflen);
1874 extern unsigned long move_page_tables(struct vm_area_struct *vma,
1875 unsigned long old_addr, struct vm_area_struct *new_vma,
1876 unsigned long new_addr, unsigned long len,
1877 bool need_rmap_locks);
1880 * Flags used by change_protection(). For now we make it a bitmap so
1881 * that we can pass in multiple flags just like parameters. However
1882 * for now all the callers are only use one of the flags at the same
1885 /* Whether we should allow dirty bit accounting */
1886 #define MM_CP_DIRTY_ACCT (1UL << 0)
1887 /* Whether this protection change is for NUMA hints */
1888 #define MM_CP_PROT_NUMA (1UL << 1)
1889 /* Whether this change is for write protecting */
1890 #define MM_CP_UFFD_WP (1UL << 2) /* do wp */
1891 #define MM_CP_UFFD_WP_RESOLVE (1UL << 3) /* Resolve wp */
1892 #define MM_CP_UFFD_WP_ALL (MM_CP_UFFD_WP | \
1893 MM_CP_UFFD_WP_RESOLVE)
1895 extern unsigned long change_protection(struct vm_area_struct *vma, unsigned long start,
1896 unsigned long end, pgprot_t newprot,
1897 unsigned long cp_flags);
1898 extern int mprotect_fixup(struct vm_area_struct *vma,
1899 struct vm_area_struct **pprev, unsigned long start,
1900 unsigned long end, unsigned long newflags);
1903 * doesn't attempt to fault and will return short.
1905 int get_user_pages_fast_only(unsigned long start, int nr_pages,
1906 unsigned int gup_flags, struct page **pages);
1907 int pin_user_pages_fast_only(unsigned long start, int nr_pages,
1908 unsigned int gup_flags, struct page **pages);
1910 static inline bool get_user_page_fast_only(unsigned long addr,
1911 unsigned int gup_flags, struct page **pagep)
1913 return get_user_pages_fast_only(addr, 1, gup_flags, pagep) == 1;
1916 * per-process(per-mm_struct) statistics.
1918 static inline unsigned long get_mm_counter(struct mm_struct *mm, int member)
1920 long val = atomic_long_read(&mm->rss_stat.count[member]);
1922 #ifdef SPLIT_RSS_COUNTING
1924 * counter is updated in asynchronous manner and may go to minus.
1925 * But it's never be expected number for users.
1930 return (unsigned long)val;
1933 void mm_trace_rss_stat(struct mm_struct *mm, int member, long count);
1935 static inline void add_mm_counter(struct mm_struct *mm, int member, long value)
1937 long count = atomic_long_add_return(value, &mm->rss_stat.count[member]);
1939 mm_trace_rss_stat(mm, member, count);
1942 static inline void inc_mm_counter(struct mm_struct *mm, int member)
1944 long count = atomic_long_inc_return(&mm->rss_stat.count[member]);
1946 mm_trace_rss_stat(mm, member, count);
1949 static inline void dec_mm_counter(struct mm_struct *mm, int member)
1951 long count = atomic_long_dec_return(&mm->rss_stat.count[member]);
1953 mm_trace_rss_stat(mm, member, count);
1956 /* Optimized variant when page is already known not to be PageAnon */
1957 static inline int mm_counter_file(struct page *page)
1959 if (PageSwapBacked(page))
1960 return MM_SHMEMPAGES;
1961 return MM_FILEPAGES;
1964 static inline int mm_counter(struct page *page)
1967 return MM_ANONPAGES;
1968 return mm_counter_file(page);
1971 static inline unsigned long get_mm_rss(struct mm_struct *mm)
1973 return get_mm_counter(mm, MM_FILEPAGES) +
1974 get_mm_counter(mm, MM_ANONPAGES) +
1975 get_mm_counter(mm, MM_SHMEMPAGES);
1978 static inline unsigned long get_mm_hiwater_rss(struct mm_struct *mm)
1980 return max(mm->hiwater_rss, get_mm_rss(mm));
1983 static inline unsigned long get_mm_hiwater_vm(struct mm_struct *mm)
1985 return max(mm->hiwater_vm, mm->total_vm);
1988 static inline void update_hiwater_rss(struct mm_struct *mm)
1990 unsigned long _rss = get_mm_rss(mm);
1992 if ((mm)->hiwater_rss < _rss)
1993 (mm)->hiwater_rss = _rss;
1996 static inline void update_hiwater_vm(struct mm_struct *mm)
1998 if (mm->hiwater_vm < mm->total_vm)
1999 mm->hiwater_vm = mm->total_vm;
2002 static inline void reset_mm_hiwater_rss(struct mm_struct *mm)
2004 mm->hiwater_rss = get_mm_rss(mm);
2007 static inline void setmax_mm_hiwater_rss(unsigned long *maxrss,
2008 struct mm_struct *mm)
2010 unsigned long hiwater_rss = get_mm_hiwater_rss(mm);
2012 if (*maxrss < hiwater_rss)
2013 *maxrss = hiwater_rss;
2016 #if defined(SPLIT_RSS_COUNTING)
2017 void sync_mm_rss(struct mm_struct *mm);
2019 static inline void sync_mm_rss(struct mm_struct *mm)
2024 #ifndef CONFIG_ARCH_HAS_PTE_SPECIAL
2025 static inline int pte_special(pte_t pte)
2030 static inline pte_t pte_mkspecial(pte_t pte)
2036 #ifndef CONFIG_ARCH_HAS_PTE_DEVMAP
2037 static inline int pte_devmap(pte_t pte)
2043 int vma_wants_writenotify(struct vm_area_struct *vma, pgprot_t vm_page_prot);
2045 extern pte_t *__get_locked_pte(struct mm_struct *mm, unsigned long addr,
2047 static inline pte_t *get_locked_pte(struct mm_struct *mm, unsigned long addr,
2051 __cond_lock(*ptl, ptep = __get_locked_pte(mm, addr, ptl));
2055 #ifdef __PAGETABLE_P4D_FOLDED
2056 static inline int __p4d_alloc(struct mm_struct *mm, pgd_t *pgd,
2057 unsigned long address)
2062 int __p4d_alloc(struct mm_struct *mm, pgd_t *pgd, unsigned long address);
2065 #if defined(__PAGETABLE_PUD_FOLDED) || !defined(CONFIG_MMU)
2066 static inline int __pud_alloc(struct mm_struct *mm, p4d_t *p4d,
2067 unsigned long address)
2071 static inline void mm_inc_nr_puds(struct mm_struct *mm) {}
2072 static inline void mm_dec_nr_puds(struct mm_struct *mm) {}
2075 int __pud_alloc(struct mm_struct *mm, p4d_t *p4d, unsigned long address);
2077 static inline void mm_inc_nr_puds(struct mm_struct *mm)
2079 if (mm_pud_folded(mm))
2081 atomic_long_add(PTRS_PER_PUD * sizeof(pud_t), &mm->pgtables_bytes);
2084 static inline void mm_dec_nr_puds(struct mm_struct *mm)
2086 if (mm_pud_folded(mm))
2088 atomic_long_sub(PTRS_PER_PUD * sizeof(pud_t), &mm->pgtables_bytes);
2092 #if defined(__PAGETABLE_PMD_FOLDED) || !defined(CONFIG_MMU)
2093 static inline int __pmd_alloc(struct mm_struct *mm, pud_t *pud,
2094 unsigned long address)
2099 static inline void mm_inc_nr_pmds(struct mm_struct *mm) {}
2100 static inline void mm_dec_nr_pmds(struct mm_struct *mm) {}
2103 int __pmd_alloc(struct mm_struct *mm, pud_t *pud, unsigned long address);
2105 static inline void mm_inc_nr_pmds(struct mm_struct *mm)
2107 if (mm_pmd_folded(mm))
2109 atomic_long_add(PTRS_PER_PMD * sizeof(pmd_t), &mm->pgtables_bytes);
2112 static inline void mm_dec_nr_pmds(struct mm_struct *mm)
2114 if (mm_pmd_folded(mm))
2116 atomic_long_sub(PTRS_PER_PMD * sizeof(pmd_t), &mm->pgtables_bytes);
2121 static inline void mm_pgtables_bytes_init(struct mm_struct *mm)
2123 atomic_long_set(&mm->pgtables_bytes, 0);
2126 static inline unsigned long mm_pgtables_bytes(const struct mm_struct *mm)
2128 return atomic_long_read(&mm->pgtables_bytes);
2131 static inline void mm_inc_nr_ptes(struct mm_struct *mm)
2133 atomic_long_add(PTRS_PER_PTE * sizeof(pte_t), &mm->pgtables_bytes);
2136 static inline void mm_dec_nr_ptes(struct mm_struct *mm)
2138 atomic_long_sub(PTRS_PER_PTE * sizeof(pte_t), &mm->pgtables_bytes);
2142 static inline void mm_pgtables_bytes_init(struct mm_struct *mm) {}
2143 static inline unsigned long mm_pgtables_bytes(const struct mm_struct *mm)
2148 static inline void mm_inc_nr_ptes(struct mm_struct *mm) {}
2149 static inline void mm_dec_nr_ptes(struct mm_struct *mm) {}
2152 int __pte_alloc(struct mm_struct *mm, pmd_t *pmd);
2153 int __pte_alloc_kernel(pmd_t *pmd);
2155 #if defined(CONFIG_MMU)
2157 static inline p4d_t *p4d_alloc(struct mm_struct *mm, pgd_t *pgd,
2158 unsigned long address)
2160 return (unlikely(pgd_none(*pgd)) && __p4d_alloc(mm, pgd, address)) ?
2161 NULL : p4d_offset(pgd, address);
2164 static inline pud_t *pud_alloc(struct mm_struct *mm, p4d_t *p4d,
2165 unsigned long address)
2167 return (unlikely(p4d_none(*p4d)) && __pud_alloc(mm, p4d, address)) ?
2168 NULL : pud_offset(p4d, address);
2171 static inline pmd_t *pmd_alloc(struct mm_struct *mm, pud_t *pud, unsigned long address)
2173 return (unlikely(pud_none(*pud)) && __pmd_alloc(mm, pud, address))?
2174 NULL: pmd_offset(pud, address);
2176 #endif /* CONFIG_MMU */
2178 #if USE_SPLIT_PTE_PTLOCKS
2179 #if ALLOC_SPLIT_PTLOCKS
2180 void __init ptlock_cache_init(void);
2181 extern bool ptlock_alloc(struct page *page);
2182 extern void ptlock_free(struct page *page);
2184 static inline spinlock_t *ptlock_ptr(struct page *page)
2188 #else /* ALLOC_SPLIT_PTLOCKS */
2189 static inline void ptlock_cache_init(void)
2193 static inline bool ptlock_alloc(struct page *page)
2198 static inline void ptlock_free(struct page *page)
2202 static inline spinlock_t *ptlock_ptr(struct page *page)
2206 #endif /* ALLOC_SPLIT_PTLOCKS */
2208 static inline spinlock_t *pte_lockptr(struct mm_struct *mm, pmd_t *pmd)
2210 return ptlock_ptr(pmd_page(*pmd));
2213 static inline bool ptlock_init(struct page *page)
2216 * prep_new_page() initialize page->private (and therefore page->ptl)
2217 * with 0. Make sure nobody took it in use in between.
2219 * It can happen if arch try to use slab for page table allocation:
2220 * slab code uses page->slab_cache, which share storage with page->ptl.
2222 VM_BUG_ON_PAGE(*(unsigned long *)&page->ptl, page);
2223 if (!ptlock_alloc(page))
2225 spin_lock_init(ptlock_ptr(page));
2229 #else /* !USE_SPLIT_PTE_PTLOCKS */
2231 * We use mm->page_table_lock to guard all pagetable pages of the mm.
2233 static inline spinlock_t *pte_lockptr(struct mm_struct *mm, pmd_t *pmd)
2235 return &mm->page_table_lock;
2237 static inline void ptlock_cache_init(void) {}
2238 static inline bool ptlock_init(struct page *page) { return true; }
2239 static inline void ptlock_free(struct page *page) {}
2240 #endif /* USE_SPLIT_PTE_PTLOCKS */
2242 static inline void pgtable_init(void)
2244 ptlock_cache_init();
2245 pgtable_cache_init();
2248 static inline bool pgtable_pte_page_ctor(struct page *page)
2250 if (!ptlock_init(page))
2252 __SetPageTable(page);
2253 inc_lruvec_page_state(page, NR_PAGETABLE);
2257 static inline void pgtable_pte_page_dtor(struct page *page)
2260 __ClearPageTable(page);
2261 dec_lruvec_page_state(page, NR_PAGETABLE);
2264 #define pte_offset_map_lock(mm, pmd, address, ptlp) \
2266 spinlock_t *__ptl = pte_lockptr(mm, pmd); \
2267 pte_t *__pte = pte_offset_map(pmd, address); \
2273 #define pte_unmap_unlock(pte, ptl) do { \
2278 #define pte_alloc(mm, pmd) (unlikely(pmd_none(*(pmd))) && __pte_alloc(mm, pmd))
2280 #define pte_alloc_map(mm, pmd, address) \
2281 (pte_alloc(mm, pmd) ? NULL : pte_offset_map(pmd, address))
2283 #define pte_alloc_map_lock(mm, pmd, address, ptlp) \
2284 (pte_alloc(mm, pmd) ? \
2285 NULL : pte_offset_map_lock(mm, pmd, address, ptlp))
2287 #define pte_alloc_kernel(pmd, address) \
2288 ((unlikely(pmd_none(*(pmd))) && __pte_alloc_kernel(pmd))? \
2289 NULL: pte_offset_kernel(pmd, address))
2291 #if USE_SPLIT_PMD_PTLOCKS
2293 static struct page *pmd_to_page(pmd_t *pmd)
2295 unsigned long mask = ~(PTRS_PER_PMD * sizeof(pmd_t) - 1);
2296 return virt_to_page((void *)((unsigned long) pmd & mask));
2299 static inline spinlock_t *pmd_lockptr(struct mm_struct *mm, pmd_t *pmd)
2301 return ptlock_ptr(pmd_to_page(pmd));
2304 static inline bool pmd_ptlock_init(struct page *page)
2306 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
2307 page->pmd_huge_pte = NULL;
2309 return ptlock_init(page);
2312 static inline void pmd_ptlock_free(struct page *page)
2314 #ifdef CONFIG_TRANSPARENT_HUGEPAGE
2315 VM_BUG_ON_PAGE(page->pmd_huge_pte, page);
2320 #define pmd_huge_pte(mm, pmd) (pmd_to_page(pmd)->pmd_huge_pte)
2324 static inline spinlock_t *pmd_lockptr(struct mm_struct *mm, pmd_t *pmd)
2326 return &mm->page_table_lock;
2329 static inline bool pmd_ptlock_init(struct page *page) { return true; }
2330 static inline void pmd_ptlock_free(struct page *page) {}
2332 #define pmd_huge_pte(mm, pmd) ((mm)->pmd_huge_pte)
2336 static inline spinlock_t *pmd_lock(struct mm_struct *mm, pmd_t *pmd)
2338 spinlock_t *ptl = pmd_lockptr(mm, pmd);
2343 static inline bool pgtable_pmd_page_ctor(struct page *page)
2345 if (!pmd_ptlock_init(page))
2347 __SetPageTable(page);
2348 inc_lruvec_page_state(page, NR_PAGETABLE);
2352 static inline void pgtable_pmd_page_dtor(struct page *page)
2354 pmd_ptlock_free(page);
2355 __ClearPageTable(page);
2356 dec_lruvec_page_state(page, NR_PAGETABLE);
2360 * No scalability reason to split PUD locks yet, but follow the same pattern
2361 * as the PMD locks to make it easier if we decide to. The VM should not be
2362 * considered ready to switch to split PUD locks yet; there may be places
2363 * which need to be converted from page_table_lock.
2365 static inline spinlock_t *pud_lockptr(struct mm_struct *mm, pud_t *pud)
2367 return &mm->page_table_lock;
2370 static inline spinlock_t *pud_lock(struct mm_struct *mm, pud_t *pud)
2372 spinlock_t *ptl = pud_lockptr(mm, pud);
2378 extern void __init pagecache_init(void);
2379 extern void __init free_area_init_memoryless_node(int nid);
2380 extern void free_initmem(void);
2383 * Free reserved pages within range [PAGE_ALIGN(start), end & PAGE_MASK)
2384 * into the buddy system. The freed pages will be poisoned with pattern
2385 * "poison" if it's within range [0, UCHAR_MAX].
2386 * Return pages freed into the buddy system.
2388 extern unsigned long free_reserved_area(void *start, void *end,
2389 int poison, const char *s);
2391 extern void adjust_managed_page_count(struct page *page, long count);
2392 extern void mem_init_print_info(void);
2394 extern void reserve_bootmem_region(phys_addr_t start, phys_addr_t end);
2396 /* Free the reserved page into the buddy system, so it gets managed. */
2397 static inline void free_reserved_page(struct page *page)
2399 ClearPageReserved(page);
2400 init_page_count(page);
2402 adjust_managed_page_count(page, 1);
2404 #define free_highmem_page(page) free_reserved_page(page)
2406 static inline void mark_page_reserved(struct page *page)
2408 SetPageReserved(page);
2409 adjust_managed_page_count(page, -1);
2413 * Default method to free all the __init memory into the buddy system.
2414 * The freed pages will be poisoned with pattern "poison" if it's within
2415 * range [0, UCHAR_MAX].
2416 * Return pages freed into the buddy system.
2418 static inline unsigned long free_initmem_default(int poison)
2420 extern char __init_begin[], __init_end[];
2422 return free_reserved_area(&__init_begin, &__init_end,
2423 poison, "unused kernel image (initmem)");
2426 static inline unsigned long get_num_physpages(void)
2429 unsigned long phys_pages = 0;
2431 for_each_online_node(nid)
2432 phys_pages += node_present_pages(nid);
2438 * Using memblock node mappings, an architecture may initialise its
2439 * zones, allocate the backing mem_map and account for memory holes in an
2440 * architecture independent manner.
2442 * An architecture is expected to register range of page frames backed by
2443 * physical memory with memblock_add[_node]() before calling
2444 * free_area_init() passing in the PFN each zone ends at. At a basic
2445 * usage, an architecture is expected to do something like
2447 * unsigned long max_zone_pfns[MAX_NR_ZONES] = {max_dma, max_normal_pfn,
2449 * for_each_valid_physical_page_range()
2450 * memblock_add_node(base, size, nid)
2451 * free_area_init(max_zone_pfns);
2453 void free_area_init(unsigned long *max_zone_pfn);
2454 unsigned long node_map_pfn_alignment(void);
2455 unsigned long __absent_pages_in_range(int nid, unsigned long start_pfn,
2456 unsigned long end_pfn);
2457 extern unsigned long absent_pages_in_range(unsigned long start_pfn,
2458 unsigned long end_pfn);
2459 extern void get_pfn_range_for_nid(unsigned int nid,
2460 unsigned long *start_pfn, unsigned long *end_pfn);
2461 extern unsigned long find_min_pfn_with_active_regions(void);
2464 static inline int early_pfn_to_nid(unsigned long pfn)
2469 /* please see mm/page_alloc.c */
2470 extern int __meminit early_pfn_to_nid(unsigned long pfn);
2473 extern void set_dma_reserve(unsigned long new_dma_reserve);
2474 extern void memmap_init_range(unsigned long, int, unsigned long,
2475 unsigned long, unsigned long, enum meminit_context,
2476 struct vmem_altmap *, int migratetype);
2477 extern void setup_per_zone_wmarks(void);
2478 extern int __meminit init_per_zone_wmark_min(void);
2479 extern void mem_init(void);
2480 extern void __init mmap_init(void);
2481 extern void show_mem(unsigned int flags, nodemask_t *nodemask);
2482 extern long si_mem_available(void);
2483 extern void si_meminfo(struct sysinfo * val);
2484 extern void si_meminfo_node(struct sysinfo *val, int nid);
2485 #ifdef __HAVE_ARCH_RESERVED_KERNEL_PAGES
2486 extern unsigned long arch_reserved_kernel_pages(void);
2489 extern __printf(3, 4)
2490 void warn_alloc(gfp_t gfp_mask, nodemask_t *nodemask, const char *fmt, ...);
2492 extern void setup_per_cpu_pageset(void);
2495 extern int min_free_kbytes;
2496 extern int watermark_boost_factor;
2497 extern int watermark_scale_factor;
2498 extern bool arch_has_descending_max_zone_pfns(void);
2501 extern atomic_long_t mmap_pages_allocated;
2502 extern int nommu_shrink_inode_mappings(struct inode *, size_t, size_t);
2504 /* interval_tree.c */
2505 void vma_interval_tree_insert(struct vm_area_struct *node,
2506 struct rb_root_cached *root);
2507 void vma_interval_tree_insert_after(struct vm_area_struct *node,
2508 struct vm_area_struct *prev,
2509 struct rb_root_cached *root);
2510 void vma_interval_tree_remove(struct vm_area_struct *node,
2511 struct rb_root_cached *root);
2512 struct vm_area_struct *vma_interval_tree_iter_first(struct rb_root_cached *root,
2513 unsigned long start, unsigned long last);
2514 struct vm_area_struct *vma_interval_tree_iter_next(struct vm_area_struct *node,
2515 unsigned long start, unsigned long last);
2517 #define vma_interval_tree_foreach(vma, root, start, last) \
2518 for (vma = vma_interval_tree_iter_first(root, start, last); \
2519 vma; vma = vma_interval_tree_iter_next(vma, start, last))
2521 void anon_vma_interval_tree_insert(struct anon_vma_chain *node,
2522 struct rb_root_cached *root);
2523 void anon_vma_interval_tree_remove(struct anon_vma_chain *node,
2524 struct rb_root_cached *root);
2525 struct anon_vma_chain *
2526 anon_vma_interval_tree_iter_first(struct rb_root_cached *root,
2527 unsigned long start, unsigned long last);
2528 struct anon_vma_chain *anon_vma_interval_tree_iter_next(
2529 struct anon_vma_chain *node, unsigned long start, unsigned long last);
2530 #ifdef CONFIG_DEBUG_VM_RB
2531 void anon_vma_interval_tree_verify(struct anon_vma_chain *node);
2534 #define anon_vma_interval_tree_foreach(avc, root, start, last) \
2535 for (avc = anon_vma_interval_tree_iter_first(root, start, last); \
2536 avc; avc = anon_vma_interval_tree_iter_next(avc, start, last))
2539 extern int __vm_enough_memory(struct mm_struct *mm, long pages, int cap_sys_admin);
2540 extern int __vma_adjust(struct vm_area_struct *vma, unsigned long start,
2541 unsigned long end, pgoff_t pgoff, struct vm_area_struct *insert,
2542 struct vm_area_struct *expand);
2543 static inline int vma_adjust(struct vm_area_struct *vma, unsigned long start,
2544 unsigned long end, pgoff_t pgoff, struct vm_area_struct *insert)
2546 return __vma_adjust(vma, start, end, pgoff, insert, NULL);
2548 extern struct vm_area_struct *vma_merge(struct mm_struct *,
2549 struct vm_area_struct *prev, unsigned long addr, unsigned long end,
2550 unsigned long vm_flags, struct anon_vma *, struct file *, pgoff_t,
2551 struct mempolicy *, struct vm_userfaultfd_ctx);
2552 extern struct anon_vma *find_mergeable_anon_vma(struct vm_area_struct *);
2553 extern int __split_vma(struct mm_struct *, struct vm_area_struct *,
2554 unsigned long addr, int new_below);
2555 extern int split_vma(struct mm_struct *, struct vm_area_struct *,
2556 unsigned long addr, int new_below);
2557 extern int insert_vm_struct(struct mm_struct *, struct vm_area_struct *);
2558 extern void __vma_link_rb(struct mm_struct *, struct vm_area_struct *,
2559 struct rb_node **, struct rb_node *);
2560 extern void unlink_file_vma(struct vm_area_struct *);
2561 extern struct vm_area_struct *copy_vma(struct vm_area_struct **,
2562 unsigned long addr, unsigned long len, pgoff_t pgoff,
2563 bool *need_rmap_locks);
2564 extern void exit_mmap(struct mm_struct *);
2566 static inline int check_data_rlimit(unsigned long rlim,
2568 unsigned long start,
2569 unsigned long end_data,
2570 unsigned long start_data)
2572 if (rlim < RLIM_INFINITY) {
2573 if (((new - start) + (end_data - start_data)) > rlim)
2580 extern int mm_take_all_locks(struct mm_struct *mm);
2581 extern void mm_drop_all_locks(struct mm_struct *mm);
2583 extern void set_mm_exe_file(struct mm_struct *mm, struct file *new_exe_file);
2584 extern struct file *get_mm_exe_file(struct mm_struct *mm);
2585 extern struct file *get_task_exe_file(struct task_struct *task);
2587 extern bool may_expand_vm(struct mm_struct *, vm_flags_t, unsigned long npages);
2588 extern void vm_stat_account(struct mm_struct *, vm_flags_t, long npages);
2590 extern bool vma_is_special_mapping(const struct vm_area_struct *vma,
2591 const struct vm_special_mapping *sm);
2592 extern struct vm_area_struct *_install_special_mapping(struct mm_struct *mm,
2593 unsigned long addr, unsigned long len,
2594 unsigned long flags,
2595 const struct vm_special_mapping *spec);
2596 /* This is an obsolete alternative to _install_special_mapping. */
2597 extern int install_special_mapping(struct mm_struct *mm,
2598 unsigned long addr, unsigned long len,
2599 unsigned long flags, struct page **pages);
2601 unsigned long randomize_stack_top(unsigned long stack_top);
2603 extern unsigned long get_unmapped_area(struct file *, unsigned long, unsigned long, unsigned long, unsigned long);
2605 extern unsigned long mmap_region(struct file *file, unsigned long addr,
2606 unsigned long len, vm_flags_t vm_flags, unsigned long pgoff,
2607 struct list_head *uf);
2608 extern unsigned long do_mmap(struct file *file, unsigned long addr,
2609 unsigned long len, unsigned long prot, unsigned long flags,
2610 unsigned long pgoff, unsigned long *populate, struct list_head *uf);
2611 extern int __do_munmap(struct mm_struct *, unsigned long, size_t,
2612 struct list_head *uf, bool downgrade);
2613 extern int do_munmap(struct mm_struct *, unsigned long, size_t,
2614 struct list_head *uf);
2615 extern int do_madvise(struct mm_struct *mm, unsigned long start, size_t len_in, int behavior);
2618 extern int __mm_populate(unsigned long addr, unsigned long len,
2620 static inline void mm_populate(unsigned long addr, unsigned long len)
2623 (void) __mm_populate(addr, len, 1);
2626 static inline void mm_populate(unsigned long addr, unsigned long len) {}
2629 /* These take the mm semaphore themselves */
2630 extern int __must_check vm_brk(unsigned long, unsigned long);
2631 extern int __must_check vm_brk_flags(unsigned long, unsigned long, unsigned long);
2632 extern int vm_munmap(unsigned long, size_t);
2633 extern unsigned long __must_check vm_mmap(struct file *, unsigned long,
2634 unsigned long, unsigned long,
2635 unsigned long, unsigned long);
2637 struct vm_unmapped_area_info {
2638 #define VM_UNMAPPED_AREA_TOPDOWN 1
2639 unsigned long flags;
2640 unsigned long length;
2641 unsigned long low_limit;
2642 unsigned long high_limit;
2643 unsigned long align_mask;
2644 unsigned long align_offset;
2647 extern unsigned long vm_unmapped_area(struct vm_unmapped_area_info *info);
2650 extern void truncate_inode_pages(struct address_space *, loff_t);
2651 extern void truncate_inode_pages_range(struct address_space *,
2652 loff_t lstart, loff_t lend);
2653 extern void truncate_inode_pages_final(struct address_space *);
2655 /* generic vm_area_ops exported for stackable file systems */
2656 extern vm_fault_t filemap_fault(struct vm_fault *vmf);
2657 extern vm_fault_t filemap_map_pages(struct vm_fault *vmf,
2658 pgoff_t start_pgoff, pgoff_t end_pgoff);
2659 extern vm_fault_t filemap_page_mkwrite(struct vm_fault *vmf);
2661 /* mm/page-writeback.c */
2662 int __must_check write_one_page(struct page *page);
2663 void task_dirty_inc(struct task_struct *tsk);
2665 extern unsigned long stack_guard_gap;
2666 /* Generic expand stack which grows the stack according to GROWS{UP,DOWN} */
2667 extern int expand_stack(struct vm_area_struct *vma, unsigned long address);
2669 /* CONFIG_STACK_GROWSUP still needs to grow downwards at some places */
2670 extern int expand_downwards(struct vm_area_struct *vma,
2671 unsigned long address);
2673 extern int expand_upwards(struct vm_area_struct *vma, unsigned long address);
2675 #define expand_upwards(vma, address) (0)
2678 /* Look up the first VMA which satisfies addr < vm_end, NULL if none. */
2679 extern struct vm_area_struct * find_vma(struct mm_struct * mm, unsigned long addr);
2680 extern struct vm_area_struct * find_vma_prev(struct mm_struct * mm, unsigned long addr,
2681 struct vm_area_struct **pprev);
2684 * find_vma_intersection() - Look up the first VMA which intersects the interval
2685 * @mm: The process address space.
2686 * @start_addr: The inclusive start user address.
2687 * @end_addr: The exclusive end user address.
2689 * Returns: The first VMA within the provided range, %NULL otherwise. Assumes
2690 * start_addr < end_addr.
2693 struct vm_area_struct *find_vma_intersection(struct mm_struct *mm,
2694 unsigned long start_addr,
2695 unsigned long end_addr)
2697 struct vm_area_struct *vma = find_vma(mm, start_addr);
2699 if (vma && end_addr <= vma->vm_start)
2705 * vma_lookup() - Find a VMA at a specific address
2706 * @mm: The process address space.
2707 * @addr: The user address.
2709 * Return: The vm_area_struct at the given address, %NULL otherwise.
2712 struct vm_area_struct *vma_lookup(struct mm_struct *mm, unsigned long addr)
2714 struct vm_area_struct *vma = find_vma(mm, addr);
2716 if (vma && addr < vma->vm_start)
2722 static inline unsigned long vm_start_gap(struct vm_area_struct *vma)
2724 unsigned long vm_start = vma->vm_start;
2726 if (vma->vm_flags & VM_GROWSDOWN) {
2727 vm_start -= stack_guard_gap;
2728 if (vm_start > vma->vm_start)
2734 static inline unsigned long vm_end_gap(struct vm_area_struct *vma)
2736 unsigned long vm_end = vma->vm_end;
2738 if (vma->vm_flags & VM_GROWSUP) {
2739 vm_end += stack_guard_gap;
2740 if (vm_end < vma->vm_end)
2741 vm_end = -PAGE_SIZE;
2746 static inline unsigned long vma_pages(struct vm_area_struct *vma)
2748 return (vma->vm_end - vma->vm_start) >> PAGE_SHIFT;
2751 /* Look up the first VMA which exactly match the interval vm_start ... vm_end */
2752 static inline struct vm_area_struct *find_exact_vma(struct mm_struct *mm,
2753 unsigned long vm_start, unsigned long vm_end)
2755 struct vm_area_struct *vma = find_vma(mm, vm_start);
2757 if (vma && (vma->vm_start != vm_start || vma->vm_end != vm_end))
2763 static inline bool range_in_vma(struct vm_area_struct *vma,
2764 unsigned long start, unsigned long end)
2766 return (vma && vma->vm_start <= start && end <= vma->vm_end);
2770 pgprot_t vm_get_page_prot(unsigned long vm_flags);
2771 void vma_set_page_prot(struct vm_area_struct *vma);
2773 static inline pgprot_t vm_get_page_prot(unsigned long vm_flags)
2777 static inline void vma_set_page_prot(struct vm_area_struct *vma)
2779 vma->vm_page_prot = vm_get_page_prot(vma->vm_flags);
2783 void vma_set_file(struct vm_area_struct *vma, struct file *file);
2785 #ifdef CONFIG_NUMA_BALANCING
2786 unsigned long change_prot_numa(struct vm_area_struct *vma,
2787 unsigned long start, unsigned long end);
2790 struct vm_area_struct *find_extend_vma(struct mm_struct *, unsigned long addr);
2791 int remap_pfn_range(struct vm_area_struct *, unsigned long addr,
2792 unsigned long pfn, unsigned long size, pgprot_t);
2793 int remap_pfn_range_notrack(struct vm_area_struct *vma, unsigned long addr,
2794 unsigned long pfn, unsigned long size, pgprot_t prot);
2795 int vm_insert_page(struct vm_area_struct *, unsigned long addr, struct page *);
2796 int vm_insert_pages(struct vm_area_struct *vma, unsigned long addr,
2797 struct page **pages, unsigned long *num);
2798 int vm_map_pages(struct vm_area_struct *vma, struct page **pages,
2800 int vm_map_pages_zero(struct vm_area_struct *vma, struct page **pages,
2802 vm_fault_t vmf_insert_pfn(struct vm_area_struct *vma, unsigned long addr,
2804 vm_fault_t vmf_insert_pfn_prot(struct vm_area_struct *vma, unsigned long addr,
2805 unsigned long pfn, pgprot_t pgprot);
2806 vm_fault_t vmf_insert_mixed(struct vm_area_struct *vma, unsigned long addr,
2808 vm_fault_t vmf_insert_mixed_prot(struct vm_area_struct *vma, unsigned long addr,
2809 pfn_t pfn, pgprot_t pgprot);
2810 vm_fault_t vmf_insert_mixed_mkwrite(struct vm_area_struct *vma,
2811 unsigned long addr, pfn_t pfn);
2812 int vm_iomap_memory(struct vm_area_struct *vma, phys_addr_t start, unsigned long len);
2814 static inline vm_fault_t vmf_insert_page(struct vm_area_struct *vma,
2815 unsigned long addr, struct page *page)
2817 int err = vm_insert_page(vma, addr, page);
2820 return VM_FAULT_OOM;
2821 if (err < 0 && err != -EBUSY)
2822 return VM_FAULT_SIGBUS;
2824 return VM_FAULT_NOPAGE;
2827 #ifndef io_remap_pfn_range
2828 static inline int io_remap_pfn_range(struct vm_area_struct *vma,
2829 unsigned long addr, unsigned long pfn,
2830 unsigned long size, pgprot_t prot)
2832 return remap_pfn_range(vma, addr, pfn, size, pgprot_decrypted(prot));
2836 static inline vm_fault_t vmf_error(int err)
2839 return VM_FAULT_OOM;
2840 return VM_FAULT_SIGBUS;
2843 struct page *follow_page(struct vm_area_struct *vma, unsigned long address,
2844 unsigned int foll_flags);
2846 #define FOLL_WRITE 0x01 /* check pte is writable */
2847 #define FOLL_TOUCH 0x02 /* mark page accessed */
2848 #define FOLL_GET 0x04 /* do get_page on page */
2849 #define FOLL_DUMP 0x08 /* give error on hole if it would be zero */
2850 #define FOLL_FORCE 0x10 /* get_user_pages read/write w/o permission */
2851 #define FOLL_NOWAIT 0x20 /* if a disk transfer is needed, start the IO
2852 * and return without waiting upon it */
2853 #define FOLL_POPULATE 0x40 /* fault in page */
2854 #define FOLL_HWPOISON 0x100 /* check page is hwpoisoned */
2855 #define FOLL_NUMA 0x200 /* force NUMA hinting page fault */
2856 #define FOLL_MIGRATION 0x400 /* wait for page to replace migration entry */
2857 #define FOLL_TRIED 0x800 /* a retry, previous pass started an IO */
2858 #define FOLL_MLOCK 0x1000 /* lock present pages */
2859 #define FOLL_REMOTE 0x2000 /* we are working on non-current tsk/mm */
2860 #define FOLL_COW 0x4000 /* internal GUP flag */
2861 #define FOLL_ANON 0x8000 /* don't do file mappings */
2862 #define FOLL_LONGTERM 0x10000 /* mapping lifetime is indefinite: see below */
2863 #define FOLL_SPLIT_PMD 0x20000 /* split huge pmd before returning */
2864 #define FOLL_PIN 0x40000 /* pages must be released via unpin_user_page */
2865 #define FOLL_FAST_ONLY 0x80000 /* gup_fast: prevent fall-back to slow gup */
2868 * FOLL_PIN and FOLL_LONGTERM may be used in various combinations with each
2869 * other. Here is what they mean, and how to use them:
2871 * FOLL_LONGTERM indicates that the page will be held for an indefinite time
2872 * period _often_ under userspace control. This is in contrast to
2873 * iov_iter_get_pages(), whose usages are transient.
2875 * FIXME: For pages which are part of a filesystem, mappings are subject to the
2876 * lifetime enforced by the filesystem and we need guarantees that longterm
2877 * users like RDMA and V4L2 only establish mappings which coordinate usage with
2878 * the filesystem. Ideas for this coordination include revoking the longterm
2879 * pin, delaying writeback, bounce buffer page writeback, etc. As FS DAX was
2880 * added after the problem with filesystems was found FS DAX VMAs are
2881 * specifically failed. Filesystem pages are still subject to bugs and use of
2882 * FOLL_LONGTERM should be avoided on those pages.
2884 * FIXME: Also NOTE that FOLL_LONGTERM is not supported in every GUP call.
2885 * Currently only get_user_pages() and get_user_pages_fast() support this flag
2886 * and calls to get_user_pages_[un]locked are specifically not allowed. This
2887 * is due to an incompatibility with the FS DAX check and
2888 * FAULT_FLAG_ALLOW_RETRY.
2890 * In the CMA case: long term pins in a CMA region would unnecessarily fragment
2891 * that region. And so, CMA attempts to migrate the page before pinning, when
2892 * FOLL_LONGTERM is specified.
2894 * FOLL_PIN indicates that a special kind of tracking (not just page->_refcount,
2895 * but an additional pin counting system) will be invoked. This is intended for
2896 * anything that gets a page reference and then touches page data (for example,
2897 * Direct IO). This lets the filesystem know that some non-file-system entity is
2898 * potentially changing the pages' data. In contrast to FOLL_GET (whose pages
2899 * are released via put_page()), FOLL_PIN pages must be released, ultimately, by
2900 * a call to unpin_user_page().
2902 * FOLL_PIN is similar to FOLL_GET: both of these pin pages. They use different
2903 * and separate refcounting mechanisms, however, and that means that each has
2904 * its own acquire and release mechanisms:
2906 * FOLL_GET: get_user_pages*() to acquire, and put_page() to release.
2908 * FOLL_PIN: pin_user_pages*() to acquire, and unpin_user_pages to release.
2910 * FOLL_PIN and FOLL_GET are mutually exclusive for a given function call.
2911 * (The underlying pages may experience both FOLL_GET-based and FOLL_PIN-based
2912 * calls applied to them, and that's perfectly OK. This is a constraint on the
2913 * callers, not on the pages.)
2915 * FOLL_PIN should be set internally by the pin_user_pages*() APIs, never
2916 * directly by the caller. That's in order to help avoid mismatches when
2917 * releasing pages: get_user_pages*() pages must be released via put_page(),
2918 * while pin_user_pages*() pages must be released via unpin_user_page().
2920 * Please see Documentation/core-api/pin_user_pages.rst for more information.
2923 static inline int vm_fault_to_errno(vm_fault_t vm_fault, int foll_flags)
2925 if (vm_fault & VM_FAULT_OOM)
2927 if (vm_fault & (VM_FAULT_HWPOISON | VM_FAULT_HWPOISON_LARGE))
2928 return (foll_flags & FOLL_HWPOISON) ? -EHWPOISON : -EFAULT;
2929 if (vm_fault & (VM_FAULT_SIGBUS | VM_FAULT_SIGSEGV))
2934 typedef int (*pte_fn_t)(pte_t *pte, unsigned long addr, void *data);
2935 extern int apply_to_page_range(struct mm_struct *mm, unsigned long address,
2936 unsigned long size, pte_fn_t fn, void *data);
2937 extern int apply_to_existing_page_range(struct mm_struct *mm,
2938 unsigned long address, unsigned long size,
2939 pte_fn_t fn, void *data);
2941 extern void init_mem_debugging_and_hardening(void);
2942 #ifdef CONFIG_PAGE_POISONING
2943 extern void __kernel_poison_pages(struct page *page, int numpages);
2944 extern void __kernel_unpoison_pages(struct page *page, int numpages);
2945 extern bool _page_poisoning_enabled_early;
2946 DECLARE_STATIC_KEY_FALSE(_page_poisoning_enabled);
2947 static inline bool page_poisoning_enabled(void)
2949 return _page_poisoning_enabled_early;
2952 * For use in fast paths after init_mem_debugging() has run, or when a
2953 * false negative result is not harmful when called too early.
2955 static inline bool page_poisoning_enabled_static(void)
2957 return static_branch_unlikely(&_page_poisoning_enabled);
2959 static inline void kernel_poison_pages(struct page *page, int numpages)
2961 if (page_poisoning_enabled_static())
2962 __kernel_poison_pages(page, numpages);
2964 static inline void kernel_unpoison_pages(struct page *page, int numpages)
2966 if (page_poisoning_enabled_static())
2967 __kernel_unpoison_pages(page, numpages);
2970 static inline bool page_poisoning_enabled(void) { return false; }
2971 static inline bool page_poisoning_enabled_static(void) { return false; }
2972 static inline void __kernel_poison_pages(struct page *page, int nunmpages) { }
2973 static inline void kernel_poison_pages(struct page *page, int numpages) { }
2974 static inline void kernel_unpoison_pages(struct page *page, int numpages) { }
2977 DECLARE_STATIC_KEY_MAYBE(CONFIG_INIT_ON_ALLOC_DEFAULT_ON, init_on_alloc);
2978 static inline bool want_init_on_alloc(gfp_t flags)
2980 if (static_branch_maybe(CONFIG_INIT_ON_ALLOC_DEFAULT_ON,
2983 return flags & __GFP_ZERO;
2986 DECLARE_STATIC_KEY_MAYBE(CONFIG_INIT_ON_FREE_DEFAULT_ON, init_on_free);
2987 static inline bool want_init_on_free(void)
2989 return static_branch_maybe(CONFIG_INIT_ON_FREE_DEFAULT_ON,
2993 extern bool _debug_pagealloc_enabled_early;
2994 DECLARE_STATIC_KEY_FALSE(_debug_pagealloc_enabled);
2996 static inline bool debug_pagealloc_enabled(void)
2998 return IS_ENABLED(CONFIG_DEBUG_PAGEALLOC) &&
2999 _debug_pagealloc_enabled_early;
3003 * For use in fast paths after init_debug_pagealloc() has run, or when a
3004 * false negative result is not harmful when called too early.
3006 static inline bool debug_pagealloc_enabled_static(void)
3008 if (!IS_ENABLED(CONFIG_DEBUG_PAGEALLOC))
3011 return static_branch_unlikely(&_debug_pagealloc_enabled);
3014 #ifdef CONFIG_DEBUG_PAGEALLOC
3016 * To support DEBUG_PAGEALLOC architecture must ensure that
3017 * __kernel_map_pages() never fails
3019 extern void __kernel_map_pages(struct page *page, int numpages, int enable);
3021 static inline void debug_pagealloc_map_pages(struct page *page, int numpages)
3023 if (debug_pagealloc_enabled_static())
3024 __kernel_map_pages(page, numpages, 1);
3027 static inline void debug_pagealloc_unmap_pages(struct page *page, int numpages)
3029 if (debug_pagealloc_enabled_static())
3030 __kernel_map_pages(page, numpages, 0);
3032 #else /* CONFIG_DEBUG_PAGEALLOC */
3033 static inline void debug_pagealloc_map_pages(struct page *page, int numpages) {}
3034 static inline void debug_pagealloc_unmap_pages(struct page *page, int numpages) {}
3035 #endif /* CONFIG_DEBUG_PAGEALLOC */
3037 #ifdef __HAVE_ARCH_GATE_AREA
3038 extern struct vm_area_struct *get_gate_vma(struct mm_struct *mm);
3039 extern int in_gate_area_no_mm(unsigned long addr);
3040 extern int in_gate_area(struct mm_struct *mm, unsigned long addr);
3042 static inline struct vm_area_struct *get_gate_vma(struct mm_struct *mm)
3046 static inline int in_gate_area_no_mm(unsigned long addr) { return 0; }
3047 static inline int in_gate_area(struct mm_struct *mm, unsigned long addr)
3051 #endif /* __HAVE_ARCH_GATE_AREA */
3053 extern bool process_shares_mm(struct task_struct *p, struct mm_struct *mm);
3055 #ifdef CONFIG_SYSCTL
3056 extern int sysctl_drop_caches;
3057 int drop_caches_sysctl_handler(struct ctl_table *, int, void *, size_t *,
3061 void drop_slab(void);
3062 void drop_slab_node(int nid);
3065 #define randomize_va_space 0
3067 extern int randomize_va_space;
3070 const char * arch_vma_name(struct vm_area_struct *vma);
3072 void print_vma_addr(char *prefix, unsigned long rip);
3074 static inline void print_vma_addr(char *prefix, unsigned long rip)
3079 int vmemmap_remap_free(unsigned long start, unsigned long end,
3080 unsigned long reuse);
3081 int vmemmap_remap_alloc(unsigned long start, unsigned long end,
3082 unsigned long reuse, gfp_t gfp_mask);
3084 void *sparse_buffer_alloc(unsigned long size);
3085 struct page * __populate_section_memmap(unsigned long pfn,
3086 unsigned long nr_pages, int nid, struct vmem_altmap *altmap);
3087 pgd_t *vmemmap_pgd_populate(unsigned long addr, int node);
3088 p4d_t *vmemmap_p4d_populate(pgd_t *pgd, unsigned long addr, int node);
3089 pud_t *vmemmap_pud_populate(p4d_t *p4d, unsigned long addr, int node);
3090 pmd_t *vmemmap_pmd_populate(pud_t *pud, unsigned long addr, int node);
3091 pte_t *vmemmap_pte_populate(pmd_t *pmd, unsigned long addr, int node,
3092 struct vmem_altmap *altmap);
3093 void *vmemmap_alloc_block(unsigned long size, int node);
3095 void *vmemmap_alloc_block_buf(unsigned long size, int node,
3096 struct vmem_altmap *altmap);
3097 void vmemmap_verify(pte_t *, int, unsigned long, unsigned long);
3098 int vmemmap_populate_basepages(unsigned long start, unsigned long end,
3099 int node, struct vmem_altmap *altmap);
3100 int vmemmap_populate(unsigned long start, unsigned long end, int node,
3101 struct vmem_altmap *altmap);
3102 void vmemmap_populate_print_last(void);
3103 #ifdef CONFIG_MEMORY_HOTPLUG
3104 void vmemmap_free(unsigned long start, unsigned long end,
3105 struct vmem_altmap *altmap);
3107 void register_page_bootmem_memmap(unsigned long section_nr, struct page *map,
3108 unsigned long nr_pages);
3111 MF_COUNT_INCREASED = 1 << 0,
3112 MF_ACTION_REQUIRED = 1 << 1,
3113 MF_MUST_KILL = 1 << 2,
3114 MF_SOFT_OFFLINE = 1 << 3,
3116 extern int memory_failure(unsigned long pfn, int flags);
3117 extern void memory_failure_queue(unsigned long pfn, int flags);
3118 extern void memory_failure_queue_kick(int cpu);
3119 extern int unpoison_memory(unsigned long pfn);
3120 extern int sysctl_memory_failure_early_kill;
3121 extern int sysctl_memory_failure_recovery;
3122 extern void shake_page(struct page *p, int access);
3123 extern atomic_long_t num_poisoned_pages __read_mostly;
3124 extern int soft_offline_page(unsigned long pfn, int flags);
3128 * Error handlers for various types of pages.
3131 MF_IGNORED, /* Error: cannot be handled */
3132 MF_FAILED, /* Error: handling failed */
3133 MF_DELAYED, /* Will be handled later */
3134 MF_RECOVERED, /* Successfully recovered */
3137 enum mf_action_page_type {
3139 MF_MSG_KERNEL_HIGH_ORDER,
3141 MF_MSG_DIFFERENT_COMPOUND,
3142 MF_MSG_POISONED_HUGE,
3145 MF_MSG_NON_PMD_HUGE,
3146 MF_MSG_UNMAP_FAILED,
3147 MF_MSG_DIRTY_SWAPCACHE,
3148 MF_MSG_CLEAN_SWAPCACHE,
3149 MF_MSG_DIRTY_MLOCKED_LRU,
3150 MF_MSG_CLEAN_MLOCKED_LRU,
3151 MF_MSG_DIRTY_UNEVICTABLE_LRU,
3152 MF_MSG_CLEAN_UNEVICTABLE_LRU,
3155 MF_MSG_TRUNCATED_LRU,
3163 #if defined(CONFIG_TRANSPARENT_HUGEPAGE) || defined(CONFIG_HUGETLBFS)
3164 extern void clear_huge_page(struct page *page,
3165 unsigned long addr_hint,
3166 unsigned int pages_per_huge_page);
3167 extern void copy_user_huge_page(struct page *dst, struct page *src,
3168 unsigned long addr_hint,
3169 struct vm_area_struct *vma,
3170 unsigned int pages_per_huge_page);
3171 extern long copy_huge_page_from_user(struct page *dst_page,
3172 const void __user *usr_src,
3173 unsigned int pages_per_huge_page,
3174 bool allow_pagefault);
3177 * vma_is_special_huge - Are transhuge page-table entries considered special?
3178 * @vma: Pointer to the struct vm_area_struct to consider
3180 * Whether transhuge page-table entries are considered "special" following
3181 * the definition in vm_normal_page().
3183 * Return: true if transhuge page-table entries should be considered special,
3186 static inline bool vma_is_special_huge(const struct vm_area_struct *vma)
3188 return vma_is_dax(vma) || (vma->vm_file &&
3189 (vma->vm_flags & (VM_PFNMAP | VM_MIXEDMAP)));
3192 #endif /* CONFIG_TRANSPARENT_HUGEPAGE || CONFIG_HUGETLBFS */
3194 #ifdef CONFIG_DEBUG_PAGEALLOC
3195 extern unsigned int _debug_guardpage_minorder;
3196 DECLARE_STATIC_KEY_FALSE(_debug_guardpage_enabled);
3198 static inline unsigned int debug_guardpage_minorder(void)
3200 return _debug_guardpage_minorder;
3203 static inline bool debug_guardpage_enabled(void)
3205 return static_branch_unlikely(&_debug_guardpage_enabled);
3208 static inline bool page_is_guard(struct page *page)
3210 if (!debug_guardpage_enabled())
3213 return PageGuard(page);
3216 static inline unsigned int debug_guardpage_minorder(void) { return 0; }
3217 static inline bool debug_guardpage_enabled(void) { return false; }
3218 static inline bool page_is_guard(struct page *page) { return false; }
3219 #endif /* CONFIG_DEBUG_PAGEALLOC */
3221 #if MAX_NUMNODES > 1
3222 void __init setup_nr_node_ids(void);
3224 static inline void setup_nr_node_ids(void) {}
3227 extern int memcmp_pages(struct page *page1, struct page *page2);
3229 static inline int pages_identical(struct page *page1, struct page *page2)
3231 return !memcmp_pages(page1, page2);
3234 #ifdef CONFIG_MAPPING_DIRTY_HELPERS
3235 unsigned long clean_record_shared_mapping_range(struct address_space *mapping,
3236 pgoff_t first_index, pgoff_t nr,
3237 pgoff_t bitmap_pgoff,
3238 unsigned long *bitmap,
3242 unsigned long wp_shared_mapping_range(struct address_space *mapping,
3243 pgoff_t first_index, pgoff_t nr);
3246 extern int sysctl_nr_trim_pages;
3248 #ifdef CONFIG_PRINTK
3249 void mem_dump_obj(void *object);
3251 static inline void mem_dump_obj(void *object) {}
3255 * seal_check_future_write - Check for F_SEAL_FUTURE_WRITE flag and handle it
3256 * @seals: the seals to check
3257 * @vma: the vma to operate on
3259 * Check whether F_SEAL_FUTURE_WRITE is set; if so, do proper check/handling on
3260 * the vma flags. Return 0 if check pass, or <0 for errors.
3262 static inline int seal_check_future_write(int seals, struct vm_area_struct *vma)
3264 if (seals & F_SEAL_FUTURE_WRITE) {
3266 * New PROT_WRITE and MAP_SHARED mmaps are not allowed when
3267 * "future write" seal active.
3269 if ((vma->vm_flags & VM_SHARED) && (vma->vm_flags & VM_WRITE))
3273 * Since an F_SEAL_FUTURE_WRITE sealed memfd can be mapped as
3274 * MAP_SHARED and read-only, take care to not allow mprotect to
3275 * revert protections on such mappings. Do this only for shared
3276 * mappings. For private mappings, don't need to mask
3277 * VM_MAYWRITE as we still want them to be COW-writable.
3279 if (vma->vm_flags & VM_SHARED)
3280 vma->vm_flags &= ~(VM_MAYWRITE);
3286 #endif /* __KERNEL__ */
3287 #endif /* _LINUX_MM_H */