diff options
Diffstat (limited to 'include/linux/mm_types.h')
| -rw-r--r-- | include/linux/mm_types.h | 1544 |
1 files changed, 1275 insertions, 269 deletions
diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h index 5a9238f6caad..d6b91e8a66d6 100644 --- a/include/linux/mm_types.h +++ b/include/linux/mm_types.h @@ -5,15 +5,21 @@ #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 <linux/types.h> #include <asm/mmu.h> @@ -24,6 +30,7 @@ struct address_space; +struct futex_private_hash; struct mem_cgroup; /* @@ -40,9 +47,7 @@ struct mem_cgroup; * 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. * - * If your page will not be mapped to userspace, you can also use the four - * bytes in the mapcount union, but you must call page_mapcount_reset() - * before freeing it. + * 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 @@ -53,16 +58,16 @@ struct mem_cgroup; * 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 be adjacent and - * double-word aligned. We align all struct pages to double-word - * boundaries, and ensure that 'freelist' is aligned within the - * struct. + * 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 +#define _struct_page_alignment __aligned(sizeof(unsigned long)) #endif struct page { @@ -78,87 +83,62 @@ struct page { struct { /* Page cache and anonymous pages */ /** * @lru: Pageout list, eg. active_list protected by - * pgdat->lru_lock. Sometimes used as a generic list + * lruvec->lru_lock. Sometimes used as a generic list * by the page owner. */ - struct list_head lru; + 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; + struct { + struct llist_node pcp_llist; + unsigned int order; + }; + }; /* See page-flags.h for PAGE_MAPPING_FLAGS */ struct address_space *mapping; - pgoff_t index; /* Our offset within mapping. */ + union { + pgoff_t __folio_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. + * Used for swp_entry_t if swapcache flag set. * Indicates order in the buddy system if PageBuddy. */ unsigned long private; }; struct { /* page_pool used by netstack */ /** - * @dma_addr: might require a 64-bit value even on - * 32-bit architectures. + * @pp_magic: magic value to avoid recycling non + * page_pool allocated pages. */ - dma_addr_t dma_addr; - }; - struct { /* slab, slob and slub */ - union { - struct list_head slab_list; - struct { /* Partial pages */ - struct page *next; -#ifdef CONFIG_64BIT - int pages; /* Nr of pages left */ - int pobjects; /* Approximate count */ -#else - short int pages; - short int pobjects; -#endif - }; - }; - struct kmem_cache *slab_cache; /* not slob */ - /* Double-word boundary */ - void *freelist; /* first free object */ - union { - void *s_mem; /* slab: first object */ - unsigned long counters; /* SLUB */ - struct { /* SLUB */ - unsigned inuse:16; - unsigned objects:15; - unsigned frozen:1; - }; - }; + 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 */ - - /* First tail page only */ - unsigned char compound_dtor; - unsigned char compound_order; - atomic_t compound_mapcount; - unsigned int compound_nr; /* 1 << compound_order */ - }; - struct { /* Second tail page of compound page */ - unsigned long _compound_pad_1; /* compound_head */ - atomic_t hpage_pinned_refcount; - /* For both global and memcg */ - struct list_head deferred_list; - }; - struct { /* Page table pages */ - unsigned long _pt_pad_1; /* compound_head */ - pgtable_t pmd_huge_pte; /* protected by page->ptl */ - unsigned long _pt_pad_2; /* mapping */ - union { - struct mm_struct *pt_mm; /* x86 pgds only */ - atomic_t pt_frag_refcount; /* powerpc */ - }; -#if ALLOC_SPLIT_PTLOCKS - spinlock_t *ptl; -#else - spinlock_t ptl; -#endif }; struct { /* ZONE_DEVICE pages */ - /** @pgmap: Points to the hosting device page map. */ - struct dev_pagemap *pgmap; + /* + * The first word is used for compound_head or folio + * pgmap + */ + void *_unused_pgmap_compound_head; void *zone_device_data; /* * ZONE_DEVICE private pages are counted as being @@ -178,31 +158,40 @@ struct page { union { /* This union is 4 bytes in size. */ /* - * If the page can be mapped to userspace, encodes the number - * of times this page is referenced by a page table. + * 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. */ - atomic_t _mapcount; + unsigned int page_type; /* - * If the page is neither PageSlab nor mappable to userspace, - * the value stored here may help determine what this page - * is used for. See page-flags.h for a list of page types - * which are currently stored here. + * 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). */ - unsigned int page_type; - - unsigned int active; /* SLAB */ - int units; /* SLOB */ + atomic_t _mapcount; }; /* Usage count. *DO NOT USE DIRECTLY*. See page_ref.h */ atomic_t _refcount; #ifdef CONFIG_MEMCG - union { - struct mem_cgroup *mem_cgroup; - struct obj_cgroup **obj_cgroups; - }; + unsigned long memcg_data; +#elif defined(CONFIG_SLAB_OBJ_EXT) + unsigned long _unused_slab_obj_exts; #endif /* @@ -223,26 +212,443 @@ struct page { #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; -static inline atomic_t *compound_mapcount_ptr(struct page *page) +/* + * 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) { - return &page[1].compound_mapcount; + BUILD_BUG_ON(flags > ENCODED_PAGE_BITS); + return (struct encoded_page *)(flags | (unsigned long)page); } -static inline atomic_t *compound_pincount_ptr(struct page *page) +static inline unsigned long encoded_page_flags(struct encoded_page *page) { - return &page[2].hpage_pinned_refcount; + 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; + +#if defined(CONFIG_MEMCG) || defined(CONFIG_SLAB_OBJ_EXT) +/* We have some extra room after the refcount in tail pages. */ +#define NR_PAGES_IN_LARGE_FOLIO +#endif + +/* + * On 32bit, we can cut the required metadata in half, because: + * (a) PID_MAX_LIMIT implicitly limits the number of MMs we could ever have, + * so we can limit MM IDs to 15 bit (32767). + * (b) We don't expect folios where even a single complete PTE mapping by + * one MM would exceed 15 bits (order-15). + */ +#ifdef CONFIG_64BIT +typedef int mm_id_mapcount_t; +#define MM_ID_MAPCOUNT_MAX INT_MAX +typedef unsigned int mm_id_t; +#else /* !CONFIG_64BIT */ +typedef short mm_id_mapcount_t; +#define MM_ID_MAPCOUNT_MAX SHRT_MAX +typedef unsigned short mm_id_t; +#endif /* CONFIG_64BIT */ + +/* We implicitly use the dummy ID for init-mm etc. where we never rmap pages. */ +#define MM_ID_DUMMY 0 +#define MM_ID_MIN (MM_ID_DUMMY + 1) + +/* + * We leave the highest bit of each MM id unused, so we can store a flag + * in the highest bit of each folio->_mm_id[]. + */ +#define MM_ID_BITS ((sizeof(mm_id_t) * BITS_PER_BYTE) - 1) +#define MM_ID_MASK ((1U << MM_ID_BITS) - 1) +#define MM_ID_MAX MM_ID_MASK + +/* + * In order to use bit_spin_lock(), which requires an unsigned long, we + * operate on folio->_mm_ids when working on flags. + */ +#define FOLIO_MM_IDS_LOCK_BITNUM MM_ID_BITS +#define FOLIO_MM_IDS_LOCK_BIT BIT(FOLIO_MM_IDS_LOCK_BITNUM) +#define FOLIO_MM_IDS_SHARED_BITNUM (2 * MM_ID_BITS + 1) +#define FOLIO_MM_IDS_SHARED_BIT BIT(FOLIO_MM_IDS_SHARED_BITNUM) + +/** + * 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. + * @share: number of DAX mappings that reference this folio. See + * dax_associate_entry. + * @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. + * @pgmap: Metadata for ZONE_DEVICE mappings + * @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(). + * @_nr_pages: Do not use directly, call folio_nr_pages(). + * @_mm_id: Do not use outside of rmap code. + * @_mm_ids: Do not use outside of rmap code. + * @_mm_id_mapcount: Do not use outside of rmap code. + * @_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 dev_pagemap *pgmap; + }; + struct address_space *mapping; + union { + pgoff_t index; + unsigned long share; + }; + 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; + union { + struct { + /* public: */ + atomic_t _large_mapcount; + atomic_t _nr_pages_mapped; +#ifdef CONFIG_64BIT + atomic_t _entire_mapcount; + atomic_t _pincount; +#endif /* CONFIG_64BIT */ + mm_id_mapcount_t _mm_id_mapcount[2]; + union { + mm_id_t _mm_id[2]; + unsigned long _mm_ids; + }; + /* private: the union with struct page is transitional */ + }; + unsigned long _usable_1[4]; + }; + atomic_t _mapcount_1; + atomic_t _refcount_1; + /* public: */ +#ifdef NR_PAGES_IN_LARGE_FOLIO + unsigned int _nr_pages; +#endif /* NR_PAGES_IN_LARGE_FOLIO */ + /* private: the union with struct page is transitional */ + }; + struct page __page_1; + }; + union { + struct { + unsigned long _flags_2; + unsigned long _head_2; + /* public: */ + struct list_head _deferred_list; +#ifndef CONFIG_64BIT + atomic_t _entire_mapcount; + atomic_t _pincount; +#endif /* !CONFIG_64BIT */ + /* private: the union with struct page is transitional */ + }; + struct page __page_2; + }; + union { + struct { + unsigned long _flags_3; + unsigned long _head_3; + /* public: */ + void *_hugetlb_subpool; + void *_hugetlb_cgroup; + void *_hugetlb_cgroup_rsvd; + void *_hugetlb_hwpoison; + /* private: the union with struct page is transitional */ + }; + struct page __page_3; + }; +}; + +#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(__folio_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); +FOLIO_MATCH(_mapcount, _mapcount_1); +FOLIO_MATCH(_refcount, _refcount_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); +#undef FOLIO_MATCH +#define FOLIO_MATCH(pg, fl) \ + static_assert(offsetof(struct folio, fl) == \ + offsetof(struct page, pg) + 3 * sizeof(struct page)) +FOLIO_MATCH(flags, _flags_3); +FOLIO_MATCH(compound_head, _head_3); +#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 gmap shadow pages + * (which are not linked into the user page tables) and x86 + * pgds. + * @_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_share_count: Used for HugeTLB PMD page table share count. + * @_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; +#ifdef CONFIG_HUGETLB_PMD_PAGE_TABLE_SHARING + atomic_t pt_share_count; +#endif + }; + + 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(__folio_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))) + +#ifdef CONFIG_HUGETLB_PMD_PAGE_TABLE_SHARING +static inline void ptdesc_pmd_pts_init(struct ptdesc *ptdesc) +{ + atomic_set(&ptdesc->pt_share_count, 0); +} + +static inline void ptdesc_pmd_pts_inc(struct ptdesc *ptdesc) +{ + atomic_inc(&ptdesc->pt_share_count); +} + +static inline void ptdesc_pmd_pts_dec(struct ptdesc *ptdesc) +{ + atomic_dec(&ptdesc->pt_share_count); +} + +static inline int ptdesc_pmd_pts_count(struct ptdesc *ptdesc) +{ + return atomic_read(&ptdesc->pt_share_count); +} +#else +static inline void ptdesc_pmd_pts_init(struct ptdesc *ptdesc) +{ +} +#endif + /* * 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) @@ -250,24 +656,20 @@ static inline void set_page_private(struct page *page, unsigned long private) page->private = 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; -}; +static inline void *folio_get_private(struct folio *folio) +{ + return folio->private; +} typedef unsigned long vm_flags_t; /* + * freeptr_t represents a SLUB freelist pointer, which might be encoded + * and not dereferenceable if CONFIG_SLAB_FREELIST_HARDENED is enabled. + */ +typedef struct { unsigned long v; } freeptr_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. @@ -296,52 +698,161 @@ 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 + +#define VMA_LOCK_OFFSET 0x40000000 +#define VMA_REF_LIMIT (VMA_LOCK_OFFSET - 1) + +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; +}; + +#ifdef __HAVE_PFNMAP_TRACKING +struct pfnmap_track_ctx { + struct kref kref; + unsigned long pfn; + unsigned long size; /* in bytes */ +}; +#endif + +/* + * Describes a VMA that is about to be mmap()'ed. Drivers may choose to + * manipulate mutable fields which will cause those fields to be updated in the + * resultant VMA. + * + * Helper functions are not required for manipulating any field. + */ +struct vm_area_desc { + /* Immutable state. */ + struct mm_struct *mm; + unsigned long start; + unsigned long end; + + /* Mutable fields. Populated with initial state. */ + pgoff_t pgoff; + struct file *file; + vm_flags_t vm_flags; + pgprot_t page_prot; + + /* Write-only fields. */ + const struct vm_operations_struct *vm_ops; + void *private_data; +}; + /* * 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). + * + * Only explicitly marked struct members may be accessed by RCU readers before + * getting a stable reference. + * + * WARNING: when adding new members, please update vm_area_init_from() to copy + * them during vm_area_struct content duplication. */ struct vm_area_struct { /* The first cache line has the info for VMA tree walking. */ - unsigned long vm_start; /* Our start address within vm_mm. */ - unsigned long vm_end; /* The first byte after our end address - within vm_mm. */ - - /* linked list of VM areas per task, sorted by address */ - struct vm_area_struct *vm_next, *vm_prev; - - struct rb_node vm_rb; + union { + struct { + /* VMA covers [vm_start; vm_end) addresses within mm */ + unsigned long vm_start; + unsigned long vm_end; + }; + freeptr_t vm_freeptr; /* Pointer used by SLAB_TYPESAFE_BY_RCU */ + }; /* - * Largest free memory gap in bytes to the left of this VMA. - * Either between this VMA and vma->vm_prev, or between one of the - * VMAs below us in the VMA rbtree and its ->vm_prev. This helps - * get_unmapped_area find a free area of the right size. + * The address space we belong to. + * Unstable RCU readers are allowed to read this. */ - unsigned long rb_subtree_gap; - - /* Second cache line starts here. */ - - struct mm_struct *vm_mm; /* The address space we belong to. */ + struct mm_struct *vm_mm; + pgprot_t vm_page_prot; /* Access permissions of this VMA. */ /* - * Access permissions of this VMA. - * See vmf_insert_mixed_prot() for discussion. + * Flags, see mm.h. + * To modify use vm_flags_{init|reset|set|clear|mod} functions. */ - pgprot_t vm_page_prot; - unsigned long vm_flags; /* Flags, see mm.h. */ + union { + const vm_flags_t vm_flags; + vm_flags_t __private __vm_flags; + }; +#ifdef CONFIG_PER_VMA_LOCK /* - * For areas with an address space and backing store, - * linkage into the address_space->i_mmap interval tree. + * Can only be written (using WRITE_ONCE()) while holding both: + * - mmap_lock (in write mode) + * - vm_refcnt bit at VMA_LOCK_OFFSET is set + * Can be read reliably while holding one of: + * - mmap_lock (in read or write mode) + * - vm_refcnt bit at VMA_LOCK_OFFSET is set or vm_refcnt > 1 + * 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. */ - struct { - struct rb_node rb; - unsigned long rb_subtree_last; - } shared; - + unsigned int vm_lock_seq; +#endif /* * 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 @@ -370,40 +881,82 @@ struct vm_area_struct { #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 +#ifdef CONFIG_PER_VMA_LOCK + /* Unstable RCU readers are allowed to read this. */ + refcount_t vm_refcnt ____cacheline_aligned_in_smp; +#ifdef CONFIG_DEBUG_LOCK_ALLOC + struct lockdep_map vmlock_dep_map; +#endif +#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; +#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 struct vm_userfaultfd_ctx vm_userfaultfd_ctx; +#ifdef __HAVE_PFNMAP_TRACKING + struct pfnmap_track_ctx *pfnmap_track_ctx; +#endif } __randomize_layout; -struct core_thread { - struct task_struct *task; - struct core_thread *next; -}; +#ifdef CONFIG_NUMA +#define vma_policy(vma) ((vma)->vm_policy) +#else +#define vma_policy(vma) NULL +#endif -struct core_state { - atomic_t nr_threads; - struct core_thread dumper; - struct completion startup; +#ifdef CONFIG_SCHED_MM_CID +struct mm_cid { + u64 time; + int cid; + int recent_cid; }; +#endif struct kioctx_table; +struct iommu_mm_data; struct mm_struct { struct { - struct vm_area_struct *mmap; /* list of VMAs */ - struct rb_root mm_rb; - u64 vmacache_seqnum; /* per-thread vmacache */ -#ifdef CONFIG_MMU - unsigned long (*get_unmapped_area) (struct file *filp, - unsigned long addr, unsigned long len, - unsigned long pgoff, unsigned long flags); -#endif + /* + * 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 adresses for compatible mmap() */ + /* 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 */ - unsigned long highest_vm_end; /* highest vma end address */ pgd_t * pgd; #ifdef CONFIG_MEMBARRIER @@ -427,33 +980,64 @@ struct mm_struct { */ atomic_t mm_users; +#ifdef CONFIG_SCHED_MM_CID /** - * @mm_count: The number of references to &struct mm_struct - * (@mm_users count as 1). + * @pcpu_cid: Per-cpu current cid. * - * Use mmgrab()/mmdrop() to modify. When this drops to 0, the - * &struct mm_struct is freed. + * Keep track of the currently allocated mm_cid for each cpu. + * The per-cpu mm_cid values are serialized by their respective + * runqueue locks. */ - atomic_t mm_count; - + 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; /** - * @has_pinned: Whether this mm has pinned any pages. This can - * be either replaced in the future by @pinned_vm when it - * becomes stable, or grow into a counter on its own. We're - * aggresive on this bit now - even if the pinned pages were - * unpinned later on, we'll still keep this bit set for the - * lifecycle of this mm just for simplicity. + * @nr_cpus_allowed: Number of CPUs allowed for mm. + * + * Number of CPUs allowed in the union of all mm's + * threads allowed CPUs. */ - atomic_t has_pinned; - + unsigned int nr_cpus_allowed; + /** + * @max_nr_cid: Maximum number of allowed concurrency + * IDs allocated. + * + * Track the highest number of allowed concurrency IDs + * allocated for the mm. + */ + atomic_t max_nr_cid; + /** + * @cpus_allowed_lock: Lock protecting mm cpus_allowed. + * + * Provide mutual exclusion for mm cpus_allowed and + * mm nr_cpus_allowed updates. + */ + raw_spinlock_t cpus_allowed_lock; +#endif #ifdef CONFIG_MMU - atomic_long_t pgtables_bytes; /* PTE page table pages */ + 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 @@ -461,7 +1045,32 @@ struct mm_struct { * init_mm.mmlist, and are protected * by mmlist_lock */ - +#ifdef CONFIG_PER_VMA_LOCK + struct rcuwait vma_writer_wait; + /* + * 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. + * Incremented every time mmap_lock is write-locked/unlocked. + * Initialized to 0, therefore odd values indicate mmap_lock + * is write-locked and even values that it's released. + * + * 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. + */ + seqcount_t mm_lock_seq; +#endif +#ifdef CONFIG_FUTEX_PRIVATE_HASH + struct mutex futex_hash_lock; + struct futex_private_hash __rcu *futex_phash; + struct futex_private_hash *futex_phash_new; +#endif unsigned long hiwater_rss; /* High-watermark of RSS usage */ unsigned long hiwater_vm; /* High-water virtual memory usage */ @@ -474,18 +1083,22 @@ struct mm_struct { 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 */ - /* - * Special counters, in some configurations protected by the - * page_table_lock, in other configurations by being atomic. - */ - struct mm_rss_stat rss_stat; + struct percpu_counter rss_stat[NR_MM_COUNTERS]; struct linux_binfmt *binfmt; @@ -494,8 +1107,6 @@ struct mm_struct { unsigned long flags; /* Must use atomic bitops to access */ - struct core_state *core_state; /* coredumping support */ - #ifdef CONFIG_AIO spinlock_t ioctx_lock; struct kioctx_table __rcu *ioctx_table; @@ -520,42 +1131,81 @@ struct mm_struct { #ifdef CONFIG_MMU_NOTIFIER struct mmu_notifier_subscriptions *notifier_subscriptions; #endif -#if defined(CONFIG_TRANSPARENT_HUGEPAGE) && !USE_SPLIT_PMD_PTLOCKS +#if defined(CONFIG_TRANSPARENT_HUGEPAGE) && !defined(CONFIG_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 the PTEs will be marked - * pte_numa. NUMA hinting faults will gather statistics and - * migrate pages to new nodes if necessary. + * 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 setting pte_numa */ + /* Restart point for scanning and remapping PTEs. */ unsigned long numa_scan_offset; - /* numa_scan_seq prevents two threads setting pte_numa */ + /* 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 or PROT_NUMA mapped page. + * moving a PROT_NONE mapped page. */ atomic_t tlb_flush_pending; #ifdef CONFIG_ARCH_WANT_BATCHED_UNMAP_TLB_FLUSH /* See flush_tlb_batched_pending() */ - bool tlb_flush_batched; + 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_SUPPORT - u32 pasid; +#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 */ +#ifdef CONFIG_MM_ID + mm_id_t mm_id; +#endif /* CONFIG_MM_ID */ } __randomize_layout; /* @@ -565,6 +1215,8 @@ struct mm_struct { 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. */ @@ -582,96 +1234,209 @@ static inline cpumask_t *mm_cpumask(struct mm_struct *mm) return (struct cpumask *)&mm->cpu_bitmap; } -struct mmu_gather; -extern void tlb_gather_mmu(struct mmu_gather *tlb, struct mm_struct *mm, - unsigned long start, unsigned long end); -extern void tlb_finish_mmu(struct mmu_gather *tlb, - unsigned long start, unsigned long end); +#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 init_tlb_flush_pending(struct mm_struct *mm) +static inline void lru_gen_init_mm(struct mm_struct *mm) { - atomic_set(&mm->tlb_flush_pending, 0); + INIT_LIST_HEAD(&mm->lru_gen.list); + mm->lru_gen.bitmap = 0; +#ifdef CONFIG_MEMCG + mm->lru_gen.memcg = NULL; +#endif } -static inline void inc_tlb_flush_pending(struct mm_struct *mm) +static inline void lru_gen_use_mm(struct mm_struct *mm) { - atomic_inc(&mm->tlb_flush_pending); /* - * The only time this value is relevant is when there are indeed pages - * to flush. And we'll only flush pages after changing them, which - * requires the PTL. - * - * So the ordering here is: - * - * atomic_inc(&mm->tlb_flush_pending); - * spin_lock(&ptl); - * ... - * set_pte_at(); - * spin_unlock(&ptl); - * - * spin_lock(&ptl) - * mm_tlb_flush_pending(); - * .... - * spin_unlock(&ptl); - * - * flush_tlb_range(); - * atomic_dec(&mm->tlb_flush_pending); - * - * Where the increment if constrained by the PTL unlock, it thus - * ensures that the increment is visible if the PTE modification is - * visible. After all, if there is no PTE modification, nobody cares - * about TLB flushes either. - * - * This very much relies on users (mm_tlb_flush_pending() and - * mm_tlb_flush_nested()) only caring about _specific_ PTEs (and - * therefore specific PTLs), because with SPLIT_PTE_PTLOCKS and RCpc - * locks (PPC) the unlock of one doesn't order against the lock of - * another PTL. - * - * The decrement is ordered by the flush_tlb_range(), such that - * mm_tlb_flush_pending() will not return false unless all flushes have - * completed. + * 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); } -static inline void dec_tlb_flush_pending(struct mm_struct *mm) +#else /* !CONFIG_LRU_GEN_WALKS_MMU */ + +static inline void lru_gen_add_mm(struct mm_struct *mm) { - /* - * See inc_tlb_flush_pending(). - * - * This cannot be smp_mb__before_atomic() because smp_mb() simply does - * not order against TLB invalidate completion, which is what we need. - * - * Therefore we must rely on tlb_flush_*() to guarantee order. - */ - atomic_dec(&mm->tlb_flush_pending); } -static inline bool mm_tlb_flush_pending(struct mm_struct *mm) +static inline void lru_gen_del_mm(struct mm_struct *mm) { - /* - * Must be called after having acquired the PTL; orders against that - * PTLs release and therefore ensures that if we observe the modified - * PTE we must also observe the increment from inc_tlb_flush_pending(). - * - * That is, it only guarantees to return true if there is a flush - * pending for _this_ PTL. - */ - return atomic_read(&mm->tlb_flush_pending); } -static inline bool mm_tlb_flush_nested(struct mm_struct *mm) +static inline void lru_gen_migrate_mm(struct mm_struct *mm) { - /* - * Similar to mm_tlb_flush_pending(), we must have acquired the PTL - * for which there is a TLB flush pending in order to guarantee - * we've seen both that PTE modification and the increment. - * - * (no requirement on actually still holding the PTL, that is irrelevant) - */ - return atomic_read(&mm->tlb_flush_pending) > 1; } +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; +} + +/* + * mm_cpus_allowed: Union of all mm's threads allowed CPUs. + */ +static inline cpumask_t *mm_cpus_allowed(struct mm_struct *mm) +{ + unsigned long bitmap = (unsigned long)mm; + + bitmap += offsetof(struct mm_struct, cpu_bitmap); + /* Skip cpu_bitmap */ + bitmap += cpumask_size(); + return (struct cpumask *)bitmap; +} + +/* Accessor for struct mm_struct's cidmask. */ +static inline cpumask_t *mm_cidmask(struct mm_struct *mm) +{ + unsigned long cid_bitmap = (unsigned long)mm_cpus_allowed(mm); + + /* Skip mm_cpus_allowed */ + cid_bitmap += cpumask_size(); + return (struct cpumask *)cid_bitmap; +} + +static inline void mm_init_cid(struct mm_struct *mm, struct task_struct *p) +{ + 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->recent_cid = MM_CID_UNSET; + pcpu_cid->time = 0; + } + mm->nr_cpus_allowed = p->nr_cpus_allowed; + atomic_set(&mm->max_nr_cid, 0); + raw_spin_lock_init(&mm->cpus_allowed_lock); + cpumask_copy(mm_cpus_allowed(mm), &p->cpus_mask); + cpumask_clear(mm_cidmask(mm)); +} + +static inline int mm_alloc_cid_noprof(struct mm_struct *mm, struct task_struct *p) +{ + mm->pcpu_cid = alloc_percpu_noprof(struct mm_cid); + if (!mm->pcpu_cid) + return -ENOMEM; + mm_init_cid(mm, p); + 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 2 * cpumask_size(); /* mm_cpus_allowed(), mm_cidmask(). */ +} + +static inline void mm_set_cpus_allowed(struct mm_struct *mm, const struct cpumask *cpumask) +{ + struct cpumask *mm_allowed = mm_cpus_allowed(mm); + + if (!mm) + return; + /* The mm_cpus_allowed is the union of each thread allowed CPUs masks. */ + raw_spin_lock(&mm->cpus_allowed_lock); + cpumask_or(mm_allowed, mm_allowed, cpumask); + WRITE_ONCE(mm->nr_cpus_allowed, cpumask_weight(mm_allowed)); + raw_spin_unlock(&mm->cpus_allowed_lock); +} +#else /* CONFIG_SCHED_MM_CID */ +static inline void mm_init_cid(struct mm_struct *mm, struct task_struct *p) { } +static inline int mm_alloc_cid(struct mm_struct *mm, struct task_struct *p) { return 0; } +static inline void mm_destroy_cid(struct mm_struct *mm) { } + +static inline unsigned int mm_cid_size(void) +{ + return 0; +} +static inline void mm_set_cpus_allowed(struct mm_struct *mm, const struct cpumask *cpumask) { } +#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; /** @@ -690,7 +1455,6 @@ typedef __bitwise unsigned int vm_fault_t; * @VM_FAULT_OOM: Out Of Memory * @VM_FAULT_SIGBUS: Bad access * @VM_FAULT_MAJOR: Page read from storage - * @VM_FAULT_WRITE: Special case for get_user_pages * @VM_FAULT_HWPOISON: Hit poisoned small page * @VM_FAULT_HWPOISON_LARGE: Hit poisoned large page. Index encoded * in upper bits @@ -703,6 +1467,7 @@ typedef __bitwise unsigned int vm_fault_t; * @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 * */ @@ -710,7 +1475,6 @@ 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_WRITE = (__force vm_fault_t)0x000008, 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, @@ -720,6 +1484,7 @@ enum vm_fault_reason { 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, }; @@ -735,7 +1500,6 @@ enum vm_fault_reason { { VM_FAULT_OOM, "OOM" }, \ { VM_FAULT_SIGBUS, "SIGBUS" }, \ { VM_FAULT_MAJOR, "MAJOR" }, \ - { VM_FAULT_WRITE, "WRITE" }, \ { VM_FAULT_HWPOISON, "HWPOISON" }, \ { VM_FAULT_HWPOISON_LARGE, "HWPOISON_LARGE" }, \ { VM_FAULT_SIGSEGV, "SIGSEGV" }, \ @@ -744,7 +1508,8 @@ enum vm_fault_reason { { VM_FAULT_RETRY, "RETRY" }, \ { VM_FAULT_FALLBACK, "FALLBACK" }, \ { VM_FAULT_DONE_COW, "DONE_COW" }, \ - { VM_FAULT_NEEDDSYNC, "NEEDDSYNC" } + { VM_FAULT_NEEDDSYNC, "NEEDDSYNC" }, \ + { VM_FAULT_COMPLETED, "COMPLETED" } struct vm_special_mapping { const char *name; /* The name, e.g. "[vdso]". */ @@ -767,6 +1532,9 @@ struct vm_special_mapping { int (*mremap)(const struct vm_special_mapping *sm, struct vm_area_struct *new_vma); + + void (*close)(const struct vm_special_mapping *sm, + struct vm_area_struct *vma); }; enum tlb_flush_reason { @@ -775,15 +1543,253 @@ enum tlb_flush_reason { TLB_LOCAL_SHOOTDOWN, TLB_LOCAL_MM_SHOOTDOWN, TLB_REMOTE_SEND_IPI, + TLB_REMOTE_WRONG_CPU, NR_TLB_FLUSH_REASONS, }; - /* - * 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; +/** + * 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 */ +}; + +/* mm flags */ + +/* + * The first two bits represent core dump modes for set-user-ID, + * the modes are SUID_DUMP_* defined in linux/sched/coredump.h + */ +#define MMF_DUMPABLE_BITS 2 +#define MMF_DUMPABLE_MASK ((1 << MMF_DUMPABLE_BITS) - 1) +/* coredump filter bits */ +#define MMF_DUMP_ANON_PRIVATE 2 +#define MMF_DUMP_ANON_SHARED 3 +#define MMF_DUMP_MAPPED_PRIVATE 4 +#define MMF_DUMP_MAPPED_SHARED 5 +#define MMF_DUMP_ELF_HEADERS 6 +#define MMF_DUMP_HUGETLB_PRIVATE 7 +#define MMF_DUMP_HUGETLB_SHARED 8 +#define MMF_DUMP_DAX_PRIVATE 9 +#define MMF_DUMP_DAX_SHARED 10 + +#define MMF_DUMP_FILTER_SHIFT MMF_DUMPABLE_BITS +#define MMF_DUMP_FILTER_BITS 9 +#define MMF_DUMP_FILTER_MASK \ + (((1 << MMF_DUMP_FILTER_BITS) - 1) << MMF_DUMP_FILTER_SHIFT) +#define MMF_DUMP_FILTER_DEFAULT \ + ((1 << MMF_DUMP_ANON_PRIVATE) | (1 << MMF_DUMP_ANON_SHARED) |\ + (1 << MMF_DUMP_HUGETLB_PRIVATE) | MMF_DUMP_MASK_DEFAULT_ELF) + +#ifdef CONFIG_CORE_DUMP_DEFAULT_ELF_HEADERS +# define MMF_DUMP_MASK_DEFAULT_ELF (1 << MMF_DUMP_ELF_HEADERS) +#else +# define MMF_DUMP_MASK_DEFAULT_ELF 0 +#endif + /* leave room for more dump flags */ +#define MMF_VM_MERGEABLE 16 /* KSM may merge identical pages */ +#define MMF_VM_HUGEPAGE 17 /* set when mm is available for khugepaged */ + +/* + * This one-shot flag is dropped due to necessity of changing exe once again + * on NFS restore + */ +//#define MMF_EXE_FILE_CHANGED 18 /* see prctl_set_mm_exe_file() */ + +#define MMF_HAS_UPROBES 19 /* has uprobes */ +#define MMF_RECALC_UPROBES 20 /* MMF_HAS_UPROBES can be wrong */ +#define MMF_OOM_SKIP 21 /* mm is of no interest for the OOM killer */ +#define MMF_UNSTABLE 22 /* mm is unstable for copy_from_user */ +#define MMF_HUGE_ZERO_PAGE 23 /* mm has ever used the global huge zero page */ +#define MMF_DISABLE_THP 24 /* disable THP for all VMAs */ +#define MMF_DISABLE_THP_MASK (1 << MMF_DISABLE_THP) +#define MMF_OOM_REAP_QUEUED 25 /* mm was queued for oom_reaper */ +#define MMF_MULTIPROCESS 26 /* mm is shared between processes */ +/* + * MMF_HAS_PINNED: Whether this mm has pinned any pages. This can be either + * replaced in the future by mm.pinned_vm when it becomes stable, or grow into + * a counter on its own. We're aggresive on this bit for now: even if the + * pinned pages were unpinned later on, we'll still keep this bit set for the + * lifecycle of this mm, just for simplicity. + */ +#define MMF_HAS_PINNED 27 /* FOLL_PIN has run, never cleared */ + +#define MMF_HAS_MDWE 28 +#define MMF_HAS_MDWE_MASK (1 << MMF_HAS_MDWE) + + +#define MMF_HAS_MDWE_NO_INHERIT 29 + +#define MMF_VM_MERGE_ANY 30 +#define MMF_VM_MERGE_ANY_MASK (1 << MMF_VM_MERGE_ANY) + +#define MMF_TOPDOWN 31 /* mm searches top down by default */ +#define MMF_TOPDOWN_MASK (1 << MMF_TOPDOWN) + +#define MMF_INIT_MASK (MMF_DUMPABLE_MASK | MMF_DUMP_FILTER_MASK |\ + MMF_DISABLE_THP_MASK | MMF_HAS_MDWE_MASK |\ + MMF_VM_MERGE_ANY_MASK | MMF_TOPDOWN_MASK) + +static inline unsigned long mmf_init_flags(unsigned long flags) +{ + if (flags & (1UL << MMF_HAS_MDWE_NO_INHERIT)) + flags &= ~((1UL << MMF_HAS_MDWE) | + (1UL << MMF_HAS_MDWE_NO_INHERIT)); + return flags & MMF_INIT_MASK; +} #endif /* _LINUX_MM_TYPES_H */ |