Contributors: 120
| Author |
Tokens |
Token Proportion |
Commits |
Commit Proportion |
| Matthew Wilcox |
368 |
11.55% |
23 |
7.64% |
| Mathieu Desnoyers |
351 |
11.01% |
5 |
1.66% |
| Vishal Moola (Oracle) |
149 |
4.68% |
2 |
0.66% |
| Linus Torvalds |
146 |
4.58% |
7 |
2.33% |
| Linus Torvalds (pre-git) |
141 |
4.42% |
34 |
11.30% |
| Yu Zhao |
140 |
4.39% |
2 |
0.66% |
| Souptick Joarder |
138 |
4.33% |
2 |
0.66% |
| Hugh Dickins |
110 |
3.45% |
7 |
2.33% |
| Suren Baghdasaryan |
107 |
3.36% |
9 |
2.99% |
| Jason Gunthorpe |
88 |
2.76% |
4 |
1.33% |
| Arnd Bergmann |
75 |
2.35% |
3 |
1.00% |
| David Hildenbrand |
73 |
2.29% |
9 |
2.99% |
| Rik Van Riel |
69 |
2.17% |
5 |
1.66% |
| Mel Gorman |
59 |
1.85% |
10 |
3.32% |
| Motohiro Kosaki |
59 |
1.85% |
2 |
0.66% |
| Andrea Arcangeli |
56 |
1.76% |
3 |
1.00% |
| Andrew Morton |
51 |
1.60% |
9 |
2.99% |
| Andrew Lutomirski |
50 |
1.57% |
4 |
1.33% |
| Martin Schwidefsky |
44 |
1.38% |
1 |
0.33% |
| Peter Zijlstra |
43 |
1.35% |
8 |
2.66% |
| David Howells |
37 |
1.16% |
4 |
1.33% |
| Rusty Russell |
35 |
1.10% |
1 |
0.33% |
| Alexander Duyck |
33 |
1.04% |
3 |
1.00% |
| Christoph Lameter |
29 |
0.91% |
5 |
1.66% |
| Michel Lespinasse |
26 |
0.82% |
4 |
1.33% |
| Kirill A. Shutemov |
23 |
0.72% |
8 |
2.66% |
| Alex Shi |
23 |
0.72% |
1 |
0.33% |
| Heiko Carstens |
22 |
0.69% |
1 |
0.33% |
| Peter Xu |
20 |
0.63% |
3 |
1.00% |
| Colin Cross |
20 |
0.63% |
1 |
0.33% |
| Dmitry Safonov |
20 |
0.63% |
2 |
0.66% |
| MinChan Kim |
19 |
0.60% |
1 |
0.33% |
| Liam R. Howlett |
18 |
0.56% |
4 |
1.33% |
| Alexander Potapenko |
18 |
0.56% |
1 |
0.33% |
| Xiao Jiang |
17 |
0.53% |
1 |
0.33% |
| Dan J Williams |
17 |
0.53% |
2 |
0.66% |
| Lance Yang |
16 |
0.50% |
1 |
0.33% |
| Dave Hansen |
16 |
0.50% |
2 |
0.66% |
| Ingo Molnar |
16 |
0.50% |
4 |
1.33% |
| Kefeng Wang |
15 |
0.47% |
1 |
0.33% |
| Matteo Croce |
14 |
0.44% |
1 |
0.33% |
| xu xin |
14 |
0.44% |
2 |
0.66% |
| Raghavendra K T |
13 |
0.41% |
3 |
1.00% |
| Thomas Gleixner |
12 |
0.38% |
1 |
0.33% |
| JoonSoo Kim |
12 |
0.38% |
3 |
1.00% |
| Alexey Dobriyan |
11 |
0.35% |
3 |
1.00% |
| Qi Zheng |
11 |
0.35% |
1 |
0.33% |
| Olaf Hering |
10 |
0.31% |
1 |
0.33% |
| Will Deacon |
10 |
0.31% |
1 |
0.33% |
| Johannes Weiner |
10 |
0.31% |
2 |
0.66% |
| Sidhartha Kumar |
10 |
0.31% |
1 |
0.33% |
| Jay Lan |
9 |
0.28% |
1 |
0.33% |
| Lorenzo Stoakes |
9 |
0.28% |
3 |
1.00% |
| Shiyang Ruan |
9 |
0.28% |
1 |
0.33% |
| Fenghua Yu |
9 |
0.28% |
2 |
0.66% |
| Wei Yang |
9 |
0.28% |
1 |
0.33% |
| Roman Gushchin |
8 |
0.25% |
2 |
0.66% |
| Michal Hocko |
8 |
0.25% |
2 |
0.66% |
| Vladimir Davydov |
7 |
0.22% |
2 |
0.66% |
| Jeff Dike |
7 |
0.22% |
1 |
0.33% |
| Roland McGrath |
7 |
0.22% |
1 |
0.33% |
| Benjamin LaHaise |
7 |
0.22% |
1 |
0.33% |
| Kamezawa Hiroyuki |
7 |
0.22% |
2 |
0.66% |
| Shakeel Butt |
7 |
0.22% |
1 |
0.33% |
| Tina Zhang |
7 |
0.22% |
1 |
0.33% |
| Thomas Hellstrom |
7 |
0.22% |
1 |
0.33% |
| Kinsey Ho |
7 |
0.22% |
1 |
0.33% |
| Srikar Dronamraju |
7 |
0.22% |
2 |
0.66% |
| Pavel Emelyanov |
7 |
0.22% |
1 |
0.33% |
| Jesper Dangaard Brouer |
6 |
0.19% |
1 |
0.33% |
| Matt Helsley |
6 |
0.19% |
1 |
0.33% |
| Ian Campbell |
6 |
0.19% |
1 |
0.33% |
| Mike Frysinger |
6 |
0.19% |
1 |
0.33% |
| Pavel Tatashin |
6 |
0.19% |
1 |
0.33% |
| Andi Kleen |
6 |
0.19% |
1 |
0.33% |
| Naoya Horiguchi |
6 |
0.19% |
1 |
0.33% |
| Nicholas Piggin |
6 |
0.19% |
2 |
0.66% |
| David Windsor |
5 |
0.16% |
1 |
0.33% |
| Paul Mundt |
5 |
0.16% |
1 |
0.33% |
| Benjamin Herrenschmidt |
5 |
0.16% |
1 |
0.33% |
| Radu Caragea |
5 |
0.16% |
1 |
0.33% |
| Cyrill V. Gorcunov |
5 |
0.16% |
1 |
0.33% |
| Hiroshi Shimamoto |
5 |
0.16% |
1 |
0.33% |
| Konstantin Khlebnikov |
5 |
0.16% |
3 |
1.00% |
| Eric W. Biedermann |
5 |
0.16% |
1 |
0.33% |
| jing yangyang |
5 |
0.16% |
1 |
0.33% |
| Vincent Guittot |
4 |
0.13% |
1 |
0.33% |
| Nikhil P Rao |
4 |
0.13% |
2 |
0.66% |
| Yang Shi |
4 |
0.13% |
1 |
0.33% |
| H. J. Lu |
4 |
0.13% |
1 |
0.33% |
| Huang Ying |
4 |
0.13% |
2 |
0.66% |
| Lin Yun Sheng |
3 |
0.09% |
1 |
0.33% |
| Ard Biesheuvel |
3 |
0.09% |
1 |
0.33% |
| Jann Horn |
3 |
0.09% |
2 |
0.66% |
| Richard Kennedy |
3 |
0.09% |
1 |
0.33% |
| Christoph Hellwig |
3 |
0.09% |
1 |
0.33% |
| Martin J. Bligh |
3 |
0.09% |
1 |
0.33% |
| David Woodhouse |
2 |
0.06% |
1 |
0.33% |
| Srivatsa Vaddagiri |
2 |
0.06% |
1 |
0.33% |
| Kees Cook |
2 |
0.06% |
1 |
0.33% |
| Akinobu Mita |
2 |
0.06% |
1 |
0.33% |
| Eric Dumazet |
2 |
0.06% |
1 |
0.33% |
| Logan Gunthorpe |
2 |
0.06% |
1 |
0.33% |
| Alexander Gordeev |
2 |
0.06% |
1 |
0.33% |
| Stephen Wilson |
2 |
0.06% |
1 |
0.33% |
| Balbir Singh |
2 |
0.06% |
1 |
0.33% |
| Quentin Perret |
2 |
0.06% |
1 |
0.33% |
| Jens Axboe |
2 |
0.06% |
1 |
0.33% |
| Keith Owens |
1 |
0.03% |
1 |
0.33% |
| Chengming Zhou |
1 |
0.03% |
1 |
0.33% |
| Feng Tang |
1 |
0.03% |
1 |
0.33% |
| Kele Huang |
1 |
0.03% |
1 |
0.33% |
| Zhen Lei |
1 |
0.03% |
1 |
0.33% |
| Davidlohr Bueso A |
1 |
0.03% |
1 |
0.33% |
| Liang Chen |
1 |
0.03% |
1 |
0.33% |
| Nadav Amit |
1 |
0.03% |
1 |
0.33% |
| Ralph Campbell |
1 |
0.03% |
1 |
0.33% |
| chenqiwu |
1 |
0.03% |
1 |
0.33% |
| Greg Kroah-Hartman |
1 |
0.03% |
1 |
0.33% |
| Oleg Nesterov |
1 |
0.03% |
1 |
0.33% |
| Total |
3187 |
|
301 |
|
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _LINUX_MM_TYPES_H
#define _LINUX_MM_TYPES_H
#include <linux/mm_types_task.h>
#include <linux/auxvec.h>
#include <linux/kref.h>
#include <linux/list.h>
#include <linux/spinlock.h>
#include <linux/rbtree.h>
#include <linux/maple_tree.h>
#include <linux/rwsem.h>
#include <linux/completion.h>
#include <linux/cpumask.h>
#include <linux/uprobes.h>
#include <linux/rcupdate.h>
#include <linux/page-flags-layout.h>
#include <linux/workqueue.h>
#include <linux/seqlock.h>
#include <linux/percpu_counter.h>
#include <asm/mmu.h>
#ifndef AT_VECTOR_SIZE_ARCH
#define AT_VECTOR_SIZE_ARCH 0
#endif
#define AT_VECTOR_SIZE (2*(AT_VECTOR_SIZE_ARCH + AT_VECTOR_SIZE_BASE + 1))
#define INIT_PASID 0
struct address_space;
struct mem_cgroup;
/*
* Each physical page in the system has a struct page associated with
* it to keep track of whatever it is we are using the page for at the
* moment. Note that we have no way to track which tasks are using
* a page, though if it is a pagecache page, rmap structures can tell us
* who is mapping it.
*
* If you allocate the page using alloc_pages(), you can use some of the
* space in struct page for your own purposes. The five words in the main
* union are available, except for bit 0 of the first word which must be
* kept clear. Many users use this word to store a pointer to an object
* which is guaranteed to be aligned. If you use the same storage as
* page->mapping, you must restore it to NULL before freeing the page.
*
* The mapcount field must not be used for own purposes.
*
* If you want to use the refcount field, it must be used in such a way
* that other CPUs temporarily incrementing and then decrementing the
* refcount does not cause problems. On receiving the page from
* alloc_pages(), the refcount will be positive.
*
* If you allocate pages of order > 0, you can use some of the fields
* in each subpage, but you may need to restore some of their values
* afterwards.
*
* SLUB uses cmpxchg_double() to atomically update its freelist and counters.
* That requires that freelist & counters in struct slab be adjacent and
* double-word aligned. Because struct slab currently just reinterprets the
* bits of struct page, we align all struct pages to double-word boundaries,
* and ensure that 'freelist' is aligned within struct slab.
*/
#ifdef CONFIG_HAVE_ALIGNED_STRUCT_PAGE
#define _struct_page_alignment __aligned(2 * sizeof(unsigned long))
#else
#define _struct_page_alignment __aligned(sizeof(unsigned long))
#endif
struct page {
unsigned long flags; /* Atomic flags, some possibly
* updated asynchronously */
/*
* Five words (20/40 bytes) are available in this union.
* WARNING: bit 0 of the first word is used for PageTail(). That
* means the other users of this union MUST NOT use the bit to
* avoid collision and false-positive PageTail().
*/
union {
struct { /* Page cache and anonymous pages */
/**
* @lru: Pageout list, eg. active_list protected by
* lruvec->lru_lock. Sometimes used as a generic list
* by the page owner.
*/
union {
struct list_head lru;
/* Or, for the Unevictable "LRU list" slot */
struct {
/* Always even, to negate PageTail */
void *__filler;
/* Count page's or folio's mlocks */
unsigned int mlock_count;
};
/* Or, free page */
struct list_head buddy_list;
struct list_head pcp_list;
};
/* See page-flags.h for PAGE_MAPPING_FLAGS */
struct address_space *mapping;
union {
pgoff_t index; /* Our offset within mapping. */
unsigned long share; /* share count for fsdax */
};
/**
* @private: Mapping-private opaque data.
* Usually used for buffer_heads if PagePrivate.
* Used for swp_entry_t if PageSwapCache.
* Indicates order in the buddy system if PageBuddy.
*/
unsigned long private;
};
struct { /* page_pool used by netstack */
/**
* @pp_magic: magic value to avoid recycling non
* page_pool allocated pages.
*/
unsigned long pp_magic;
struct page_pool *pp;
unsigned long _pp_mapping_pad;
unsigned long dma_addr;
atomic_long_t pp_ref_count;
};
struct { /* Tail pages of compound page */
unsigned long compound_head; /* Bit zero is set */
};
struct { /* ZONE_DEVICE pages */
/** @pgmap: Points to the hosting device page map. */
struct dev_pagemap *pgmap;
void *zone_device_data;
/*
* ZONE_DEVICE private pages are counted as being
* mapped so the next 3 words hold the mapping, index,
* and private fields from the source anonymous or
* page cache page while the page is migrated to device
* private memory.
* ZONE_DEVICE MEMORY_DEVICE_FS_DAX pages also
* use the mapping, index, and private fields when
* pmem backed DAX files are mapped.
*/
};
/** @rcu_head: You can use this to free a page by RCU. */
struct rcu_head rcu_head;
};
union { /* This union is 4 bytes in size. */
/*
* For head pages of typed folios, the value stored here
* allows for determining what this page is used for. The
* tail pages of typed folios will not store a type
* (page_type == _mapcount == -1).
*
* See page-flags.h for a list of page types which are currently
* stored here.
*
* Owners of typed folios may reuse the lower 16 bit of the
* head page page_type field after setting the page type,
* but must reset these 16 bit to -1 before clearing the
* page type.
*/
unsigned int page_type;
/*
* For pages that are part of non-typed folios for which mappings
* are tracked via the RMAP, encodes the number of times this page
* is directly referenced by a page table.
*
* Note that the mapcount is always initialized to -1, so that
* transitions both from it and to it can be tracked, using
* atomic_inc_and_test() and atomic_add_negative(-1).
*/
atomic_t _mapcount;
};
/* Usage count. *DO NOT USE DIRECTLY*. See page_ref.h */
atomic_t _refcount;
#ifdef CONFIG_MEMCG
unsigned long memcg_data;
#elif defined(CONFIG_SLAB_OBJ_EXT)
unsigned long _unused_slab_obj_exts;
#endif
/*
* On machines where all RAM is mapped into kernel address space,
* we can simply calculate the virtual address. On machines with
* highmem some memory is mapped into kernel virtual memory
* dynamically, so we need a place to store that address.
* Note that this field could be 16 bits on x86 ... ;)
*
* Architectures with slow multiplication can define
* WANT_PAGE_VIRTUAL in asm/page.h
*/
#if defined(WANT_PAGE_VIRTUAL)
void *virtual; /* Kernel virtual address (NULL if
not kmapped, ie. highmem) */
#endif /* WANT_PAGE_VIRTUAL */
#ifdef LAST_CPUPID_NOT_IN_PAGE_FLAGS
int _last_cpupid;
#endif
#ifdef CONFIG_KMSAN
/*
* KMSAN metadata for this page:
* - shadow page: every bit indicates whether the corresponding
* bit of the original page is initialized (0) or not (1);
* - origin page: every 4 bytes contain an id of the stack trace
* where the uninitialized value was created.
*/
struct page *kmsan_shadow;
struct page *kmsan_origin;
#endif
} _struct_page_alignment;
/*
* struct encoded_page - a nonexistent type marking this pointer
*
* An 'encoded_page' pointer is a pointer to a regular 'struct page', but
* with the low bits of the pointer indicating extra context-dependent
* information. Only used in mmu_gather handling, and this acts as a type
* system check on that use.
*
* We only really have two guaranteed bits in general, although you could
* play with 'struct page' alignment (see CONFIG_HAVE_ALIGNED_STRUCT_PAGE)
* for more.
*
* Use the supplied helper functions to endcode/decode the pointer and bits.
*/
struct encoded_page;
#define ENCODED_PAGE_BITS 3ul
/* Perform rmap removal after we have flushed the TLB. */
#define ENCODED_PAGE_BIT_DELAY_RMAP 1ul
/*
* The next item in an encoded_page array is the "nr_pages" argument, specifying
* the number of consecutive pages starting from this page, that all belong to
* the same folio. For example, "nr_pages" corresponds to the number of folio
* references that must be dropped. If this bit is not set, "nr_pages" is
* implicitly 1.
*/
#define ENCODED_PAGE_BIT_NR_PAGES_NEXT 2ul
static __always_inline struct encoded_page *encode_page(struct page *page, unsigned long flags)
{
BUILD_BUG_ON(flags > ENCODED_PAGE_BITS);
return (struct encoded_page *)(flags | (unsigned long)page);
}
static inline unsigned long encoded_page_flags(struct encoded_page *page)
{
return ENCODED_PAGE_BITS & (unsigned long)page;
}
static inline struct page *encoded_page_ptr(struct encoded_page *page)
{
return (struct page *)(~ENCODED_PAGE_BITS & (unsigned long)page);
}
static __always_inline struct encoded_page *encode_nr_pages(unsigned long nr)
{
VM_WARN_ON_ONCE((nr << 2) >> 2 != nr);
return (struct encoded_page *)(nr << 2);
}
static __always_inline unsigned long encoded_nr_pages(struct encoded_page *page)
{
return ((unsigned long)page) >> 2;
}
/*
* A swap entry has to fit into a "unsigned long", as the entry is hidden
* in the "index" field of the swapper address space.
*/
typedef struct {
unsigned long val;
} swp_entry_t;
/**
* struct folio - Represents a contiguous set of bytes.
* @flags: Identical to the page flags.
* @lru: Least Recently Used list; tracks how recently this folio was used.
* @mlock_count: Number of times this folio has been pinned by mlock().
* @mapping: The file this page belongs to, or refers to the anon_vma for
* anonymous memory.
* @index: Offset within the file, in units of pages. For anonymous memory,
* this is the index from the beginning of the mmap.
* @private: Filesystem per-folio data (see folio_attach_private()).
* @swap: Used for swp_entry_t if folio_test_swapcache().
* @_mapcount: Do not access this member directly. Use folio_mapcount() to
* find out how many times this folio is mapped by userspace.
* @_refcount: Do not access this member directly. Use folio_ref_count()
* to find how many references there are to this folio.
* @memcg_data: Memory Control Group data.
* @virtual: Virtual address in the kernel direct map.
* @_last_cpupid: IDs of last CPU and last process that accessed the folio.
* @_entire_mapcount: Do not use directly, call folio_entire_mapcount().
* @_large_mapcount: Do not use directly, call folio_mapcount().
* @_nr_pages_mapped: Do not use outside of rmap and debug code.
* @_pincount: Do not use directly, call folio_maybe_dma_pinned().
* @_folio_nr_pages: Do not use directly, call folio_nr_pages().
* @_hugetlb_subpool: Do not use directly, use accessor in hugetlb.h.
* @_hugetlb_cgroup: Do not use directly, use accessor in hugetlb_cgroup.h.
* @_hugetlb_cgroup_rsvd: Do not use directly, use accessor in hugetlb_cgroup.h.
* @_hugetlb_hwpoison: Do not use directly, call raw_hwp_list_head().
* @_deferred_list: Folios to be split under memory pressure.
* @_unused_slab_obj_exts: Placeholder to match obj_exts in struct slab.
*
* A folio is a physically, virtually and logically contiguous set
* of bytes. It is a power-of-two in size, and it is aligned to that
* same power-of-two. It is at least as large as %PAGE_SIZE. If it is
* in the page cache, it is at a file offset which is a multiple of that
* power-of-two. It may be mapped into userspace at an address which is
* at an arbitrary page offset, but its kernel virtual address is aligned
* to its size.
*/
struct folio {
/* private: don't document the anon union */
union {
struct {
/* public: */
unsigned long flags;
union {
struct list_head lru;
/* private: avoid cluttering the output */
struct {
void *__filler;
/* public: */
unsigned int mlock_count;
/* private: */
};
/* public: */
};
struct address_space *mapping;
pgoff_t index;
union {
void *private;
swp_entry_t swap;
};
atomic_t _mapcount;
atomic_t _refcount;
#ifdef CONFIG_MEMCG
unsigned long memcg_data;
#elif defined(CONFIG_SLAB_OBJ_EXT)
unsigned long _unused_slab_obj_exts;
#endif
#if defined(WANT_PAGE_VIRTUAL)
void *virtual;
#endif
#ifdef LAST_CPUPID_NOT_IN_PAGE_FLAGS
int _last_cpupid;
#endif
/* private: the union with struct page is transitional */
};
struct page page;
};
union {
struct {
unsigned long _flags_1;
unsigned long _head_1;
/* public: */
atomic_t _large_mapcount;
atomic_t _entire_mapcount;
atomic_t _nr_pages_mapped;
atomic_t _pincount;
#ifdef CONFIG_64BIT
unsigned int _folio_nr_pages;
#endif
/* private: the union with struct page is transitional */
};
struct page __page_1;
};
union {
struct {
unsigned long _flags_2;
unsigned long _head_2;
/* public: */
void *_hugetlb_subpool;
void *_hugetlb_cgroup;
void *_hugetlb_cgroup_rsvd;
void *_hugetlb_hwpoison;
/* private: the union with struct page is transitional */
};
struct {
unsigned long _flags_2a;
unsigned long _head_2a;
/* public: */
struct list_head _deferred_list;
/* private: the union with struct page is transitional */
};
struct page __page_2;
};
};
#define FOLIO_MATCH(pg, fl) \
static_assert(offsetof(struct page, pg) == offsetof(struct folio, fl))
FOLIO_MATCH(flags, flags);
FOLIO_MATCH(lru, lru);
FOLIO_MATCH(mapping, mapping);
FOLIO_MATCH(compound_head, lru);
FOLIO_MATCH(index, index);
FOLIO_MATCH(private, private);
FOLIO_MATCH(_mapcount, _mapcount);
FOLIO_MATCH(_refcount, _refcount);
#ifdef CONFIG_MEMCG
FOLIO_MATCH(memcg_data, memcg_data);
#endif
#if defined(WANT_PAGE_VIRTUAL)
FOLIO_MATCH(virtual, virtual);
#endif
#ifdef LAST_CPUPID_NOT_IN_PAGE_FLAGS
FOLIO_MATCH(_last_cpupid, _last_cpupid);
#endif
#undef FOLIO_MATCH
#define FOLIO_MATCH(pg, fl) \
static_assert(offsetof(struct folio, fl) == \
offsetof(struct page, pg) + sizeof(struct page))
FOLIO_MATCH(flags, _flags_1);
FOLIO_MATCH(compound_head, _head_1);
#undef FOLIO_MATCH
#define FOLIO_MATCH(pg, fl) \
static_assert(offsetof(struct folio, fl) == \
offsetof(struct page, pg) + 2 * sizeof(struct page))
FOLIO_MATCH(flags, _flags_2);
FOLIO_MATCH(compound_head, _head_2);
FOLIO_MATCH(flags, _flags_2a);
FOLIO_MATCH(compound_head, _head_2a);
#undef FOLIO_MATCH
/**
* struct ptdesc - Memory descriptor for page tables.
* @__page_flags: Same as page flags. Powerpc only.
* @pt_rcu_head: For freeing page table pages.
* @pt_list: List of used page tables. Used for s390 and x86.
* @_pt_pad_1: Padding that aliases with page's compound head.
* @pmd_huge_pte: Protected by ptdesc->ptl, used for THPs.
* @__page_mapping: Aliases with page->mapping. Unused for page tables.
* @pt_index: Used for s390 gmap.
* @pt_mm: Used for x86 pgds.
* @pt_frag_refcount: For fragmented page table tracking. Powerpc only.
* @_pt_pad_2: Padding to ensure proper alignment.
* @ptl: Lock for the page table.
* @__page_type: Same as page->page_type. Unused for page tables.
* @__page_refcount: Same as page refcount.
* @pt_memcg_data: Memcg data. Tracked for page tables here.
*
* This struct overlays struct page for now. Do not modify without a good
* understanding of the issues.
*/
struct ptdesc {
unsigned long __page_flags;
union {
struct rcu_head pt_rcu_head;
struct list_head pt_list;
struct {
unsigned long _pt_pad_1;
pgtable_t pmd_huge_pte;
};
};
unsigned long __page_mapping;
union {
pgoff_t pt_index;
struct mm_struct *pt_mm;
atomic_t pt_frag_refcount;
};
union {
unsigned long _pt_pad_2;
#if ALLOC_SPLIT_PTLOCKS
spinlock_t *ptl;
#else
spinlock_t ptl;
#endif
};
unsigned int __page_type;
atomic_t __page_refcount;
#ifdef CONFIG_MEMCG
unsigned long pt_memcg_data;
#endif
};
#define TABLE_MATCH(pg, pt) \
static_assert(offsetof(struct page, pg) == offsetof(struct ptdesc, pt))
TABLE_MATCH(flags, __page_flags);
TABLE_MATCH(compound_head, pt_list);
TABLE_MATCH(compound_head, _pt_pad_1);
TABLE_MATCH(mapping, __page_mapping);
TABLE_MATCH(index, pt_index);
TABLE_MATCH(rcu_head, pt_rcu_head);
TABLE_MATCH(page_type, __page_type);
TABLE_MATCH(_refcount, __page_refcount);
#ifdef CONFIG_MEMCG
TABLE_MATCH(memcg_data, pt_memcg_data);
#endif
#undef TABLE_MATCH
static_assert(sizeof(struct ptdesc) <= sizeof(struct page));
#define ptdesc_page(pt) (_Generic((pt), \
const struct ptdesc *: (const struct page *)(pt), \
struct ptdesc *: (struct page *)(pt)))
#define ptdesc_folio(pt) (_Generic((pt), \
const struct ptdesc *: (const struct folio *)(pt), \
struct ptdesc *: (struct folio *)(pt)))
#define page_ptdesc(p) (_Generic((p), \
const struct page *: (const struct ptdesc *)(p), \
struct page *: (struct ptdesc *)(p)))
/*
* Used for sizing the vmemmap region on some architectures
*/
#define STRUCT_PAGE_MAX_SHIFT (order_base_2(sizeof(struct page)))
#define PAGE_FRAG_CACHE_MAX_SIZE __ALIGN_MASK(32768, ~PAGE_MASK)
#define PAGE_FRAG_CACHE_MAX_ORDER get_order(PAGE_FRAG_CACHE_MAX_SIZE)
/*
* page_private can be used on tail pages. However, PagePrivate is only
* checked by the VM on the head page. So page_private on the tail pages
* should be used for data that's ancillary to the head page (eg attaching
* buffer heads to tail pages after attaching buffer heads to the head page)
*/
#define page_private(page) ((page)->private)
static inline void set_page_private(struct page *page, unsigned long private)
{
page->private = private;
}
static inline void *folio_get_private(struct folio *folio)
{
return folio->private;
}
struct page_frag_cache {
void * va;
#if (PAGE_SIZE < PAGE_FRAG_CACHE_MAX_SIZE)
__u16 offset;
__u16 size;
#else
__u32 offset;
#endif
/* we maintain a pagecount bias, so that we dont dirty cache line
* containing page->_refcount every time we allocate a fragment.
*/
unsigned int pagecnt_bias;
bool pfmemalloc;
};
typedef unsigned long vm_flags_t;
/*
* A region containing a mapping of a non-memory backed file under NOMMU
* conditions. These are held in a global tree and are pinned by the VMAs that
* map parts of them.
*/
struct vm_region {
struct rb_node vm_rb; /* link in global region tree */
vm_flags_t vm_flags; /* VMA vm_flags */
unsigned long vm_start; /* start address of region */
unsigned long vm_end; /* region initialised to here */
unsigned long vm_top; /* region allocated to here */
unsigned long vm_pgoff; /* the offset in vm_file corresponding to vm_start */
struct file *vm_file; /* the backing file or NULL */
int vm_usage; /* region usage count (access under nommu_region_sem) */
bool vm_icache_flushed : 1; /* true if the icache has been flushed for
* this region */
};
#ifdef CONFIG_USERFAULTFD
#define NULL_VM_UFFD_CTX ((struct vm_userfaultfd_ctx) { NULL, })
struct vm_userfaultfd_ctx {
struct userfaultfd_ctx *ctx;
};
#else /* CONFIG_USERFAULTFD */
#define NULL_VM_UFFD_CTX ((struct vm_userfaultfd_ctx) {})
struct vm_userfaultfd_ctx {};
#endif /* CONFIG_USERFAULTFD */
struct anon_vma_name {
struct kref kref;
/* The name needs to be at the end because it is dynamically sized. */
char name[];
};
#ifdef CONFIG_ANON_VMA_NAME
/*
* mmap_lock should be read-locked when calling anon_vma_name(). Caller should
* either keep holding the lock while using the returned pointer or it should
* raise anon_vma_name refcount before releasing the lock.
*/
struct anon_vma_name *anon_vma_name(struct vm_area_struct *vma);
struct anon_vma_name *anon_vma_name_alloc(const char *name);
void anon_vma_name_free(struct kref *kref);
#else /* CONFIG_ANON_VMA_NAME */
static inline struct anon_vma_name *anon_vma_name(struct vm_area_struct *vma)
{
return NULL;
}
static inline struct anon_vma_name *anon_vma_name_alloc(const char *name)
{
return NULL;
}
#endif
struct vma_lock {
struct rw_semaphore lock;
};
struct vma_numab_state {
/*
* Initialised as time in 'jiffies' after which VMA
* should be scanned. Delays first scan of new VMA by at
* least sysctl_numa_balancing_scan_delay:
*/
unsigned long next_scan;
/*
* Time in jiffies when pids_active[] is reset to
* detect phase change behaviour:
*/
unsigned long pids_active_reset;
/*
* Approximate tracking of PIDs that trapped a NUMA hinting
* fault. May produce false positives due to hash collisions.
*
* [0] Previous PID tracking
* [1] Current PID tracking
*
* Window moves after next_pid_reset has expired approximately
* every VMA_PID_RESET_PERIOD jiffies:
*/
unsigned long pids_active[2];
/* MM scan sequence ID when scan first started after VMA creation */
int start_scan_seq;
/*
* MM scan sequence ID when the VMA was last completely scanned.
* A VMA is not eligible for scanning if prev_scan_seq == numa_scan_seq
*/
int prev_scan_seq;
};
/*
* This struct describes a virtual memory area. There is one of these
* per VM-area/task. A VM area is any part of the process virtual memory
* space that has a special rule for the page-fault handlers (ie a shared
* library, the executable area etc).
*/
struct vm_area_struct {
/* The first cache line has the info for VMA tree walking. */
union {
struct {
/* VMA covers [vm_start; vm_end) addresses within mm */
unsigned long vm_start;
unsigned long vm_end;
};
#ifdef CONFIG_PER_VMA_LOCK
struct rcu_head vm_rcu; /* Used for deferred freeing. */
#endif
};
struct mm_struct *vm_mm; /* The address space we belong to. */
pgprot_t vm_page_prot; /* Access permissions of this VMA. */
/*
* Flags, see mm.h.
* To modify use vm_flags_{init|reset|set|clear|mod} functions.
*/
union {
const vm_flags_t vm_flags;
vm_flags_t __private __vm_flags;
};
#ifdef CONFIG_PER_VMA_LOCK
/* Flag to indicate areas detached from the mm->mm_mt tree */
bool detached;
/*
* Can only be written (using WRITE_ONCE()) while holding both:
* - mmap_lock (in write mode)
* - vm_lock->lock (in write mode)
* Can be read reliably while holding one of:
* - mmap_lock (in read or write mode)
* - vm_lock->lock (in read or write mode)
* Can be read unreliably (using READ_ONCE()) for pessimistic bailout
* while holding nothing (except RCU to keep the VMA struct allocated).
*
* This sequence counter is explicitly allowed to overflow; sequence
* counter reuse can only lead to occasional unnecessary use of the
* slowpath.
*/
int vm_lock_seq;
struct vma_lock *vm_lock;
#endif
/*
* For areas with an address space and backing store,
* linkage into the address_space->i_mmap interval tree.
*
*/
struct {
struct rb_node rb;
unsigned long rb_subtree_last;
} shared;
/*
* A file's MAP_PRIVATE vma can be in both i_mmap tree and anon_vma
* list, after a COW of one of the file pages. A MAP_SHARED vma
* can only be in the i_mmap tree. An anonymous MAP_PRIVATE, stack
* or brk vma (with NULL file) can only be in an anon_vma list.
*/
struct list_head anon_vma_chain; /* Serialized by mmap_lock &
* page_table_lock */
struct anon_vma *anon_vma; /* Serialized by page_table_lock */
/* Function pointers to deal with this struct. */
const struct vm_operations_struct *vm_ops;
/* Information about our backing store: */
unsigned long vm_pgoff; /* Offset (within vm_file) in PAGE_SIZE
units */
struct file * vm_file; /* File we map to (can be NULL). */
void * vm_private_data; /* was vm_pte (shared mem) */
#ifdef CONFIG_ANON_VMA_NAME
/*
* For private and shared anonymous mappings, a pointer to a null
* terminated string containing the name given to the vma, or NULL if
* unnamed. Serialized by mmap_lock. Use anon_vma_name to access.
*/
struct anon_vma_name *anon_name;
#endif
#ifdef CONFIG_SWAP
atomic_long_t swap_readahead_info;
#endif
#ifndef CONFIG_MMU
struct vm_region *vm_region; /* NOMMU mapping region */
#endif
#ifdef CONFIG_NUMA
struct mempolicy *vm_policy; /* NUMA policy for the VMA */
#endif
#ifdef CONFIG_NUMA_BALANCING
struct vma_numab_state *numab_state; /* NUMA Balancing state */
#endif
struct vm_userfaultfd_ctx vm_userfaultfd_ctx;
} __randomize_layout;
#ifdef CONFIG_NUMA
#define vma_policy(vma) ((vma)->vm_policy)
#else
#define vma_policy(vma) NULL
#endif
#ifdef CONFIG_SCHED_MM_CID
struct mm_cid {
u64 time;
int cid;
};
#endif
struct kioctx_table;
struct iommu_mm_data;
struct mm_struct {
struct {
/*
* Fields which are often written to are placed in a separate
* cache line.
*/
struct {
/**
* @mm_count: The number of references to &struct
* mm_struct (@mm_users count as 1).
*
* Use mmgrab()/mmdrop() to modify. When this drops to
* 0, the &struct mm_struct is freed.
*/
atomic_t mm_count;
} ____cacheline_aligned_in_smp;
struct maple_tree mm_mt;
unsigned long mmap_base; /* base of mmap area */
unsigned long mmap_legacy_base; /* base of mmap area in bottom-up allocations */
#ifdef CONFIG_HAVE_ARCH_COMPAT_MMAP_BASES
/* Base addresses for compatible mmap() */
unsigned long mmap_compat_base;
unsigned long mmap_compat_legacy_base;
#endif
unsigned long task_size; /* size of task vm space */
pgd_t * pgd;
#ifdef CONFIG_MEMBARRIER
/**
* @membarrier_state: Flags controlling membarrier behavior.
*
* This field is close to @pgd to hopefully fit in the same
* cache-line, which needs to be touched by switch_mm().
*/
atomic_t membarrier_state;
#endif
/**
* @mm_users: The number of users including userspace.
*
* Use mmget()/mmget_not_zero()/mmput() to modify. When this
* drops to 0 (i.e. when the task exits and there are no other
* temporary reference holders), we also release a reference on
* @mm_count (which may then free the &struct mm_struct if
* @mm_count also drops to 0).
*/
atomic_t mm_users;
#ifdef CONFIG_SCHED_MM_CID
/**
* @pcpu_cid: Per-cpu current cid.
*
* Keep track of the currently allocated mm_cid for each cpu.
* The per-cpu mm_cid values are serialized by their respective
* runqueue locks.
*/
struct mm_cid __percpu *pcpu_cid;
/*
* @mm_cid_next_scan: Next mm_cid scan (in jiffies).
*
* When the next mm_cid scan is due (in jiffies).
*/
unsigned long mm_cid_next_scan;
#endif
#ifdef CONFIG_MMU
atomic_long_t pgtables_bytes; /* size of all page tables */
#endif
int map_count; /* number of VMAs */
spinlock_t page_table_lock; /* Protects page tables and some
* counters
*/
/*
* With some kernel config, the current mmap_lock's offset
* inside 'mm_struct' is at 0x120, which is very optimal, as
* its two hot fields 'count' and 'owner' sit in 2 different
* cachelines, and when mmap_lock is highly contended, both
* of the 2 fields will be accessed frequently, current layout
* will help to reduce cache bouncing.
*
* So please be careful with adding new fields before
* mmap_lock, which can easily push the 2 fields into one
* cacheline.
*/
struct rw_semaphore mmap_lock;
struct list_head mmlist; /* List of maybe swapped mm's. These
* are globally strung together off
* init_mm.mmlist, and are protected
* by mmlist_lock
*/
#ifdef CONFIG_PER_VMA_LOCK
/*
* This field has lock-like semantics, meaning it is sometimes
* accessed with ACQUIRE/RELEASE semantics.
* Roughly speaking, incrementing the sequence number is
* equivalent to releasing locks on VMAs; reading the sequence
* number can be part of taking a read lock on a VMA.
*
* Can be modified under write mmap_lock using RELEASE
* semantics.
* Can be read with no other protection when holding write
* mmap_lock.
* Can be read with ACQUIRE semantics if not holding write
* mmap_lock.
*/
int mm_lock_seq;
#endif
unsigned long hiwater_rss; /* High-watermark of RSS usage */
unsigned long hiwater_vm; /* High-water virtual memory usage */
unsigned long total_vm; /* Total pages mapped */
unsigned long locked_vm; /* Pages that have PG_mlocked set */
atomic64_t pinned_vm; /* Refcount permanently increased */
unsigned long data_vm; /* VM_WRITE & ~VM_SHARED & ~VM_STACK */
unsigned long exec_vm; /* VM_EXEC & ~VM_WRITE & ~VM_STACK */
unsigned long stack_vm; /* VM_STACK */
unsigned long def_flags;
/**
* @write_protect_seq: Locked when any thread is write
* protecting pages mapped by this mm to enforce a later COW,
* for instance during page table copying for fork().
*/
seqcount_t write_protect_seq;
spinlock_t arg_lock; /* protect the below fields */
unsigned long start_code, end_code, start_data, end_data;
unsigned long start_brk, brk, start_stack;
unsigned long arg_start, arg_end, env_start, env_end;
unsigned long saved_auxv[AT_VECTOR_SIZE]; /* for /proc/PID/auxv */
struct percpu_counter rss_stat[NR_MM_COUNTERS];
struct linux_binfmt *binfmt;
/* Architecture-specific MM context */
mm_context_t context;
unsigned long flags; /* Must use atomic bitops to access */
#ifdef CONFIG_AIO
spinlock_t ioctx_lock;
struct kioctx_table __rcu *ioctx_table;
#endif
#ifdef CONFIG_MEMCG
/*
* "owner" points to a task that is regarded as the canonical
* user/owner of this mm. All of the following must be true in
* order for it to be changed:
*
* current == mm->owner
* current->mm != mm
* new_owner->mm == mm
* new_owner->alloc_lock is held
*/
struct task_struct __rcu *owner;
#endif
struct user_namespace *user_ns;
/* store ref to file /proc/<pid>/exe symlink points to */
struct file __rcu *exe_file;
#ifdef CONFIG_MMU_NOTIFIER
struct mmu_notifier_subscriptions *notifier_subscriptions;
#endif
#if defined(CONFIG_TRANSPARENT_HUGEPAGE) && !USE_SPLIT_PMD_PTLOCKS
pgtable_t pmd_huge_pte; /* protected by page_table_lock */
#endif
#ifdef CONFIG_NUMA_BALANCING
/*
* numa_next_scan is the next time that PTEs will be remapped
* PROT_NONE to trigger NUMA hinting faults; such faults gather
* statistics and migrate pages to new nodes if necessary.
*/
unsigned long numa_next_scan;
/* Restart point for scanning and remapping PTEs. */
unsigned long numa_scan_offset;
/* numa_scan_seq prevents two threads remapping PTEs. */
int numa_scan_seq;
#endif
/*
* An operation with batched TLB flushing is going on. Anything
* that can move process memory needs to flush the TLB when
* moving a PROT_NONE mapped page.
*/
atomic_t tlb_flush_pending;
#ifdef CONFIG_ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH
/* See flush_tlb_batched_pending() */
atomic_t tlb_flush_batched;
#endif
struct uprobes_state uprobes_state;
#ifdef CONFIG_PREEMPT_RT
struct rcu_head delayed_drop;
#endif
#ifdef CONFIG_HUGETLB_PAGE
atomic_long_t hugetlb_usage;
#endif
struct work_struct async_put_work;
#ifdef CONFIG_IOMMU_MM_DATA
struct iommu_mm_data *iommu_mm;
#endif
#ifdef CONFIG_KSM
/*
* Represent how many pages of this process are involved in KSM
* merging (not including ksm_zero_pages).
*/
unsigned long ksm_merging_pages;
/*
* Represent how many pages are checked for ksm merging
* including merged and not merged.
*/
unsigned long ksm_rmap_items;
/*
* Represent how many empty pages are merged with kernel zero
* pages when enabling KSM use_zero_pages.
*/
atomic_long_t ksm_zero_pages;
#endif /* CONFIG_KSM */
#ifdef CONFIG_LRU_GEN_WALKS_MMU
struct {
/* this mm_struct is on lru_gen_mm_list */
struct list_head list;
/*
* Set when switching to this mm_struct, as a hint of
* whether it has been used since the last time per-node
* page table walkers cleared the corresponding bits.
*/
unsigned long bitmap;
#ifdef CONFIG_MEMCG
/* points to the memcg of "owner" above */
struct mem_cgroup *memcg;
#endif
} lru_gen;
#endif /* CONFIG_LRU_GEN_WALKS_MMU */
} __randomize_layout;
/*
* The mm_cpumask needs to be at the end of mm_struct, because it
* is dynamically sized based on nr_cpu_ids.
*/
unsigned long cpu_bitmap[];
};
#define MM_MT_FLAGS (MT_FLAGS_ALLOC_RANGE | MT_FLAGS_LOCK_EXTERN | \
MT_FLAGS_USE_RCU)
extern struct mm_struct init_mm;
/* Pointer magic because the dynamic array size confuses some compilers. */
static inline void mm_init_cpumask(struct mm_struct *mm)
{
unsigned long cpu_bitmap = (unsigned long)mm;
cpu_bitmap += offsetof(struct mm_struct, cpu_bitmap);
cpumask_clear((struct cpumask *)cpu_bitmap);
}
/* Future-safe accessor for struct mm_struct's cpu_vm_mask. */
static inline cpumask_t *mm_cpumask(struct mm_struct *mm)
{
return (struct cpumask *)&mm->cpu_bitmap;
}
#ifdef CONFIG_LRU_GEN
struct lru_gen_mm_list {
/* mm_struct list for page table walkers */
struct list_head fifo;
/* protects the list above */
spinlock_t lock;
};
#endif /* CONFIG_LRU_GEN */
#ifdef CONFIG_LRU_GEN_WALKS_MMU
void lru_gen_add_mm(struct mm_struct *mm);
void lru_gen_del_mm(struct mm_struct *mm);
void lru_gen_migrate_mm(struct mm_struct *mm);
static inline void lru_gen_init_mm(struct mm_struct *mm)
{
INIT_LIST_HEAD(&mm->lru_gen.list);
mm->lru_gen.bitmap = 0;
#ifdef CONFIG_MEMCG
mm->lru_gen.memcg = NULL;
#endif
}
static inline void lru_gen_use_mm(struct mm_struct *mm)
{
/*
* When the bitmap is set, page reclaim knows this mm_struct has been
* used since the last time it cleared the bitmap. So it might be worth
* walking the page tables of this mm_struct to clear the accessed bit.
*/
WRITE_ONCE(mm->lru_gen.bitmap, -1);
}
#else /* !CONFIG_LRU_GEN_WALKS_MMU */
static inline void lru_gen_add_mm(struct mm_struct *mm)
{
}
static inline void lru_gen_del_mm(struct mm_struct *mm)
{
}
static inline void lru_gen_migrate_mm(struct mm_struct *mm)
{
}
static inline void lru_gen_init_mm(struct mm_struct *mm)
{
}
static inline void lru_gen_use_mm(struct mm_struct *mm)
{
}
#endif /* CONFIG_LRU_GEN_WALKS_MMU */
struct vma_iterator {
struct ma_state mas;
};
#define VMA_ITERATOR(name, __mm, __addr) \
struct vma_iterator name = { \
.mas = { \
.tree = &(__mm)->mm_mt, \
.index = __addr, \
.node = NULL, \
.status = ma_start, \
}, \
}
static inline void vma_iter_init(struct vma_iterator *vmi,
struct mm_struct *mm, unsigned long addr)
{
mas_init(&vmi->mas, &mm->mm_mt, addr);
}
#ifdef CONFIG_SCHED_MM_CID
enum mm_cid_state {
MM_CID_UNSET = -1U, /* Unset state has lazy_put flag set. */
MM_CID_LAZY_PUT = (1U << 31),
};
static inline bool mm_cid_is_unset(int cid)
{
return cid == MM_CID_UNSET;
}
static inline bool mm_cid_is_lazy_put(int cid)
{
return !mm_cid_is_unset(cid) && (cid & MM_CID_LAZY_PUT);
}
static inline bool mm_cid_is_valid(int cid)
{
return !(cid & MM_CID_LAZY_PUT);
}
static inline int mm_cid_set_lazy_put(int cid)
{
return cid | MM_CID_LAZY_PUT;
}
static inline int mm_cid_clear_lazy_put(int cid)
{
return cid & ~MM_CID_LAZY_PUT;
}
/* Accessor for struct mm_struct's cidmask. */
static inline cpumask_t *mm_cidmask(struct mm_struct *mm)
{
unsigned long cid_bitmap = (unsigned long)mm;
cid_bitmap += offsetof(struct mm_struct, cpu_bitmap);
/* Skip cpu_bitmap */
cid_bitmap += cpumask_size();
return (struct cpumask *)cid_bitmap;
}
static inline void mm_init_cid(struct mm_struct *mm)
{
int i;
for_each_possible_cpu(i) {
struct mm_cid *pcpu_cid = per_cpu_ptr(mm->pcpu_cid, i);
pcpu_cid->cid = MM_CID_UNSET;
pcpu_cid->time = 0;
}
cpumask_clear(mm_cidmask(mm));
}
static inline int mm_alloc_cid_noprof(struct mm_struct *mm)
{
mm->pcpu_cid = alloc_percpu_noprof(struct mm_cid);
if (!mm->pcpu_cid)
return -ENOMEM;
mm_init_cid(mm);
return 0;
}
#define mm_alloc_cid(...) alloc_hooks(mm_alloc_cid_noprof(__VA_ARGS__))
static inline void mm_destroy_cid(struct mm_struct *mm)
{
free_percpu(mm->pcpu_cid);
mm->pcpu_cid = NULL;
}
static inline unsigned int mm_cid_size(void)
{
return cpumask_size();
}
#else /* CONFIG_SCHED_MM_CID */
static inline void mm_init_cid(struct mm_struct *mm) { }
static inline int mm_alloc_cid(struct mm_struct *mm) { return 0; }
static inline void mm_destroy_cid(struct mm_struct *mm) { }
static inline unsigned int mm_cid_size(void)
{
return 0;
}
#endif /* CONFIG_SCHED_MM_CID */
struct mmu_gather;
extern void tlb_gather_mmu(struct mmu_gather *tlb, struct mm_struct *mm);
extern void tlb_gather_mmu_fullmm(struct mmu_gather *tlb, struct mm_struct *mm);
extern void tlb_finish_mmu(struct mmu_gather *tlb);
struct vm_fault;
/**
* typedef vm_fault_t - Return type for page fault handlers.
*
* Page fault handlers return a bitmask of %VM_FAULT values.
*/
typedef __bitwise unsigned int vm_fault_t;
/**
* enum vm_fault_reason - Page fault handlers return a bitmask of
* these values to tell the core VM what happened when handling the
* fault. Used to decide whether a process gets delivered SIGBUS or
* just gets major/minor fault counters bumped up.
*
* @VM_FAULT_OOM: Out Of Memory
* @VM_FAULT_SIGBUS: Bad access
* @VM_FAULT_MAJOR: Page read from storage
* @VM_FAULT_HWPOISON: Hit poisoned small page
* @VM_FAULT_HWPOISON_LARGE: Hit poisoned large page. Index encoded
* in upper bits
* @VM_FAULT_SIGSEGV: segmentation fault
* @VM_FAULT_NOPAGE: ->fault installed the pte, not return page
* @VM_FAULT_LOCKED: ->fault locked the returned page
* @VM_FAULT_RETRY: ->fault blocked, must retry
* @VM_FAULT_FALLBACK: huge page fault failed, fall back to small
* @VM_FAULT_DONE_COW: ->fault has fully handled COW
* @VM_FAULT_NEEDDSYNC: ->fault did not modify page tables and needs
* fsync() to complete (for synchronous page faults
* in DAX)
* @VM_FAULT_COMPLETED: ->fault completed, meanwhile mmap lock released
* @VM_FAULT_HINDEX_MASK: mask HINDEX value
*
*/
enum vm_fault_reason {
VM_FAULT_OOM = (__force vm_fault_t)0x000001,
VM_FAULT_SIGBUS = (__force vm_fault_t)0x000002,
VM_FAULT_MAJOR = (__force vm_fault_t)0x000004,
VM_FAULT_HWPOISON = (__force vm_fault_t)0x000010,
VM_FAULT_HWPOISON_LARGE = (__force vm_fault_t)0x000020,
VM_FAULT_SIGSEGV = (__force vm_fault_t)0x000040,
VM_FAULT_NOPAGE = (__force vm_fault_t)0x000100,
VM_FAULT_LOCKED = (__force vm_fault_t)0x000200,
VM_FAULT_RETRY = (__force vm_fault_t)0x000400,
VM_FAULT_FALLBACK = (__force vm_fault_t)0x000800,
VM_FAULT_DONE_COW = (__force vm_fault_t)0x001000,
VM_FAULT_NEEDDSYNC = (__force vm_fault_t)0x002000,
VM_FAULT_COMPLETED = (__force vm_fault_t)0x004000,
VM_FAULT_HINDEX_MASK = (__force vm_fault_t)0x0f0000,
};
/* Encode hstate index for a hwpoisoned large page */
#define VM_FAULT_SET_HINDEX(x) ((__force vm_fault_t)((x) << 16))
#define VM_FAULT_GET_HINDEX(x) (((__force unsigned int)(x) >> 16) & 0xf)
#define VM_FAULT_ERROR (VM_FAULT_OOM | VM_FAULT_SIGBUS | \
VM_FAULT_SIGSEGV | VM_FAULT_HWPOISON | \
VM_FAULT_HWPOISON_LARGE | VM_FAULT_FALLBACK)
#define VM_FAULT_RESULT_TRACE \
{ VM_FAULT_OOM, "OOM" }, \
{ VM_FAULT_SIGBUS, "SIGBUS" }, \
{ VM_FAULT_MAJOR, "MAJOR" }, \
{ VM_FAULT_HWPOISON, "HWPOISON" }, \
{ VM_FAULT_HWPOISON_LARGE, "HWPOISON_LARGE" }, \
{ VM_FAULT_SIGSEGV, "SIGSEGV" }, \
{ VM_FAULT_NOPAGE, "NOPAGE" }, \
{ VM_FAULT_LOCKED, "LOCKED" }, \
{ VM_FAULT_RETRY, "RETRY" }, \
{ VM_FAULT_FALLBACK, "FALLBACK" }, \
{ VM_FAULT_DONE_COW, "DONE_COW" }, \
{ VM_FAULT_NEEDDSYNC, "NEEDDSYNC" }, \
{ VM_FAULT_COMPLETED, "COMPLETED" }
struct vm_special_mapping {
const char *name; /* The name, e.g. "[vdso]". */
/*
* If .fault is not provided, this points to a
* NULL-terminated array of pages that back the special mapping.
*
* This must not be NULL unless .fault is provided.
*/
struct page **pages;
/*
* If non-NULL, then this is called to resolve page faults
* on the special mapping. If used, .pages is not checked.
*/
vm_fault_t (*fault)(const struct vm_special_mapping *sm,
struct vm_area_struct *vma,
struct vm_fault *vmf);
int (*mremap)(const struct vm_special_mapping *sm,
struct vm_area_struct *new_vma);
};
enum tlb_flush_reason {
TLB_FLUSH_ON_TASK_SWITCH,
TLB_REMOTE_SHOOTDOWN,
TLB_LOCAL_SHOOTDOWN,
TLB_LOCAL_MM_SHOOTDOWN,
TLB_REMOTE_SEND_IPI,
NR_TLB_FLUSH_REASONS,
};
/**
* enum fault_flag - Fault flag definitions.
* @FAULT_FLAG_WRITE: Fault was a write fault.
* @FAULT_FLAG_MKWRITE: Fault was mkwrite of existing PTE.
* @FAULT_FLAG_ALLOW_RETRY: Allow to retry the fault if blocked.
* @FAULT_FLAG_RETRY_NOWAIT: Don't drop mmap_lock and wait when retrying.
* @FAULT_FLAG_KILLABLE: The fault task is in SIGKILL killable region.
* @FAULT_FLAG_TRIED: The fault has been tried once.
* @FAULT_FLAG_USER: The fault originated in userspace.
* @FAULT_FLAG_REMOTE: The fault is not for current task/mm.
* @FAULT_FLAG_INSTRUCTION: The fault was during an instruction fetch.
* @FAULT_FLAG_INTERRUPTIBLE: The fault can be interrupted by non-fatal signals.
* @FAULT_FLAG_UNSHARE: The fault is an unsharing request to break COW in a
* COW mapping, making sure that an exclusive anon page is
* mapped after the fault.
* @FAULT_FLAG_ORIG_PTE_VALID: whether the fault has vmf->orig_pte cached.
* We should only access orig_pte if this flag set.
* @FAULT_FLAG_VMA_LOCK: The fault is handled under VMA lock.
*
* About @FAULT_FLAG_ALLOW_RETRY and @FAULT_FLAG_TRIED: we can specify
* whether we would allow page faults to retry by specifying these two
* fault flags correctly. Currently there can be three legal combinations:
*
* (a) ALLOW_RETRY and !TRIED: this means the page fault allows retry, and
* this is the first try
*
* (b) ALLOW_RETRY and TRIED: this means the page fault allows retry, and
* we've already tried at least once
*
* (c) !ALLOW_RETRY and !TRIED: this means the page fault does not allow retry
*
* The unlisted combination (!ALLOW_RETRY && TRIED) is illegal and should never
* be used. Note that page faults can be allowed to retry for multiple times,
* in which case we'll have an initial fault with flags (a) then later on
* continuous faults with flags (b). We should always try to detect pending
* signals before a retry to make sure the continuous page faults can still be
* interrupted if necessary.
*
* The combination FAULT_FLAG_WRITE|FAULT_FLAG_UNSHARE is illegal.
* FAULT_FLAG_UNSHARE is ignored and treated like an ordinary read fault when
* applied to mappings that are not COW mappings.
*/
enum fault_flag {
FAULT_FLAG_WRITE = 1 << 0,
FAULT_FLAG_MKWRITE = 1 << 1,
FAULT_FLAG_ALLOW_RETRY = 1 << 2,
FAULT_FLAG_RETRY_NOWAIT = 1 << 3,
FAULT_FLAG_KILLABLE = 1 << 4,
FAULT_FLAG_TRIED = 1 << 5,
FAULT_FLAG_USER = 1 << 6,
FAULT_FLAG_REMOTE = 1 << 7,
FAULT_FLAG_INSTRUCTION = 1 << 8,
FAULT_FLAG_INTERRUPTIBLE = 1 << 9,
FAULT_FLAG_UNSHARE = 1 << 10,
FAULT_FLAG_ORIG_PTE_VALID = 1 << 11,
FAULT_FLAG_VMA_LOCK = 1 << 12,
};
typedef unsigned int __bitwise zap_flags_t;
/* Flags for clear_young_dirty_ptes(). */
typedef int __bitwise cydp_t;
/* Clear the access bit */
#define CYDP_CLEAR_YOUNG ((__force cydp_t)BIT(0))
/* Clear the dirty bit */
#define CYDP_CLEAR_DIRTY ((__force cydp_t)BIT(1))
/*
* FOLL_PIN and FOLL_LONGTERM may be used in various combinations with each
* other. Here is what they mean, and how to use them:
*
*
* FIXME: For pages which are part of a filesystem, mappings are subject to the
* lifetime enforced by the filesystem and we need guarantees that longterm
* users like RDMA and V4L2 only establish mappings which coordinate usage with
* the filesystem. Ideas for this coordination include revoking the longterm
* pin, delaying writeback, bounce buffer page writeback, etc. As FS DAX was
* added after the problem with filesystems was found FS DAX VMAs are
* specifically failed. Filesystem pages are still subject to bugs and use of
* FOLL_LONGTERM should be avoided on those pages.
*
* In the CMA case: long term pins in a CMA region would unnecessarily fragment
* that region. And so, CMA attempts to migrate the page before pinning, when
* FOLL_LONGTERM is specified.
*
* FOLL_PIN indicates that a special kind of tracking (not just page->_refcount,
* but an additional pin counting system) will be invoked. This is intended for
* anything that gets a page reference and then touches page data (for example,
* Direct IO). This lets the filesystem know that some non-file-system entity is
* potentially changing the pages' data. In contrast to FOLL_GET (whose pages
* are released via put_page()), FOLL_PIN pages must be released, ultimately, by
* a call to unpin_user_page().
*
* FOLL_PIN is similar to FOLL_GET: both of these pin pages. They use different
* and separate refcounting mechanisms, however, and that means that each has
* its own acquire and release mechanisms:
*
* FOLL_GET: get_user_pages*() to acquire, and put_page() to release.
*
* FOLL_PIN: pin_user_pages*() to acquire, and unpin_user_pages to release.
*
* FOLL_PIN and FOLL_GET are mutually exclusive for a given function call.
* (The underlying pages may experience both FOLL_GET-based and FOLL_PIN-based
* calls applied to them, and that's perfectly OK. This is a constraint on the
* callers, not on the pages.)
*
* FOLL_PIN should be set internally by the pin_user_pages*() APIs, never
* directly by the caller. That's in order to help avoid mismatches when
* releasing pages: get_user_pages*() pages must be released via put_page(),
* while pin_user_pages*() pages must be released via unpin_user_page().
*
* Please see Documentation/core-api/pin_user_pages.rst for more information.
*/
enum {
/* check pte is writable */
FOLL_WRITE = 1 << 0,
/* do get_page on page */
FOLL_GET = 1 << 1,
/* give error on hole if it would be zero */
FOLL_DUMP = 1 << 2,
/* get_user_pages read/write w/o permission */
FOLL_FORCE = 1 << 3,
/*
* if a disk transfer is needed, start the IO and return without waiting
* upon it
*/
FOLL_NOWAIT = 1 << 4,
/* do not fault in pages */
FOLL_NOFAULT = 1 << 5,
/* check page is hwpoisoned */
FOLL_HWPOISON = 1 << 6,
/* don't do file mappings */
FOLL_ANON = 1 << 7,
/*
* FOLL_LONGTERM indicates that the page will be held for an indefinite
* time period _often_ under userspace control. This is in contrast to
* iov_iter_get_pages(), whose usages are transient.
*/
FOLL_LONGTERM = 1 << 8,
/* split huge pmd before returning */
FOLL_SPLIT_PMD = 1 << 9,
/* allow returning PCI P2PDMA pages */
FOLL_PCI_P2PDMA = 1 << 10,
/* allow interrupts from generic signals */
FOLL_INTERRUPTIBLE = 1 << 11,
/*
* Always honor (trigger) NUMA hinting faults.
*
* FOLL_WRITE implicitly honors NUMA hinting faults because a
* PROT_NONE-mapped page is not writable (exceptions with FOLL_FORCE
* apply). get_user_pages_fast_only() always implicitly honors NUMA
* hinting faults.
*/
FOLL_HONOR_NUMA_FAULT = 1 << 12,
/* See also internal only FOLL flags in mm/internal.h */
};
#endif /* _LINUX_MM_TYPES_H */