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Diffstat (limited to '')
| -rw-r--r-- | mm/vmalloc.c | 3589 |
1 files changed, 3589 insertions, 0 deletions
diff --git a/mm/vmalloc.c b/mm/vmalloc.c new file mode 100644 index 000000000..d6a4794fa --- /dev/null +++ b/mm/vmalloc.c @@ -0,0 +1,3589 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 1993 Linus Torvalds + * Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 1999 + * SMP-safe vmalloc/vfree/ioremap, Tigran Aivazian <tigran@veritas.com>, May 2000 + * Major rework to support vmap/vunmap, Christoph Hellwig, SGI, August 2002 + * Numa awareness, Christoph Lameter, SGI, June 2005 + * Improving global KVA allocator, Uladzislau Rezki, Sony, May 2019 + */ + +#include <linux/vmalloc.h> +#include <linux/mm.h> +#include <linux/module.h> +#include <linux/highmem.h> +#include <linux/sched/signal.h> +#include <linux/slab.h> +#include <linux/spinlock.h> +#include <linux/interrupt.h> +#include <linux/proc_fs.h> +#include <linux/seq_file.h> +#include <linux/set_memory.h> +#include <linux/debugobjects.h> +#include <linux/kallsyms.h> +#include <linux/list.h> +#include <linux/notifier.h> +#include <linux/rbtree.h> +#include <linux/xarray.h> +#include <linux/rcupdate.h> +#include <linux/pfn.h> +#include <linux/kmemleak.h> +#include <linux/atomic.h> +#include <linux/compiler.h> +#include <linux/llist.h> +#include <linux/bitops.h> +#include <linux/rbtree_augmented.h> +#include <linux/overflow.h> + +#include <linux/uaccess.h> +#include <asm/tlbflush.h> +#include <asm/shmparam.h> + +#include "internal.h" +#include "pgalloc-track.h" + +bool is_vmalloc_addr(const void *x) +{ + unsigned long addr = (unsigned long)x; + + return addr >= VMALLOC_START && addr < VMALLOC_END; +} +EXPORT_SYMBOL(is_vmalloc_addr); + +struct vfree_deferred { + struct llist_head list; + struct work_struct wq; +}; +static DEFINE_PER_CPU(struct vfree_deferred, vfree_deferred); + +static void __vunmap(const void *, int); + +static void free_work(struct work_struct *w) +{ + struct vfree_deferred *p = container_of(w, struct vfree_deferred, wq); + struct llist_node *t, *llnode; + + llist_for_each_safe(llnode, t, llist_del_all(&p->list)) + __vunmap((void *)llnode, 1); +} + +/*** Page table manipulation functions ***/ + +static void vunmap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end, + pgtbl_mod_mask *mask) +{ + pte_t *pte; + + pte = pte_offset_kernel(pmd, addr); + do { + pte_t ptent = ptep_get_and_clear(&init_mm, addr, pte); + WARN_ON(!pte_none(ptent) && !pte_present(ptent)); + } while (pte++, addr += PAGE_SIZE, addr != end); + *mask |= PGTBL_PTE_MODIFIED; +} + +static void vunmap_pmd_range(pud_t *pud, unsigned long addr, unsigned long end, + pgtbl_mod_mask *mask) +{ + pmd_t *pmd; + unsigned long next; + int cleared; + + pmd = pmd_offset(pud, addr); + do { + next = pmd_addr_end(addr, end); + + cleared = pmd_clear_huge(pmd); + if (cleared || pmd_bad(*pmd)) + *mask |= PGTBL_PMD_MODIFIED; + + if (cleared) + continue; + if (pmd_none_or_clear_bad(pmd)) + continue; + vunmap_pte_range(pmd, addr, next, mask); + + cond_resched(); + } while (pmd++, addr = next, addr != end); +} + +static void vunmap_pud_range(p4d_t *p4d, unsigned long addr, unsigned long end, + pgtbl_mod_mask *mask) +{ + pud_t *pud; + unsigned long next; + int cleared; + + pud = pud_offset(p4d, addr); + do { + next = pud_addr_end(addr, end); + + cleared = pud_clear_huge(pud); + if (cleared || pud_bad(*pud)) + *mask |= PGTBL_PUD_MODIFIED; + + if (cleared) + continue; + if (pud_none_or_clear_bad(pud)) + continue; + vunmap_pmd_range(pud, addr, next, mask); + } while (pud++, addr = next, addr != end); +} + +static void vunmap_p4d_range(pgd_t *pgd, unsigned long addr, unsigned long end, + pgtbl_mod_mask *mask) +{ + p4d_t *p4d; + unsigned long next; + int cleared; + + p4d = p4d_offset(pgd, addr); + do { + next = p4d_addr_end(addr, end); + + cleared = p4d_clear_huge(p4d); + if (cleared || p4d_bad(*p4d)) + *mask |= PGTBL_P4D_MODIFIED; + + if (cleared) + continue; + if (p4d_none_or_clear_bad(p4d)) + continue; + vunmap_pud_range(p4d, addr, next, mask); + } while (p4d++, addr = next, addr != end); +} + +/** + * unmap_kernel_range_noflush - unmap kernel VM area + * @start: start of the VM area to unmap + * @size: size of the VM area to unmap + * + * Unmap PFN_UP(@size) pages at @addr. The VM area @addr and @size specify + * should have been allocated using get_vm_area() and its friends. + * + * NOTE: + * This function does NOT do any cache flushing. The caller is responsible + * for calling flush_cache_vunmap() on to-be-mapped areas before calling this + * function and flush_tlb_kernel_range() after. + */ +void unmap_kernel_range_noflush(unsigned long start, unsigned long size) +{ + unsigned long end = start + size; + unsigned long next; + pgd_t *pgd; + unsigned long addr = start; + pgtbl_mod_mask mask = 0; + + BUG_ON(addr >= end); + pgd = pgd_offset_k(addr); + do { + next = pgd_addr_end(addr, end); + if (pgd_bad(*pgd)) + mask |= PGTBL_PGD_MODIFIED; + if (pgd_none_or_clear_bad(pgd)) + continue; + vunmap_p4d_range(pgd, addr, next, &mask); + } while (pgd++, addr = next, addr != end); + + if (mask & ARCH_PAGE_TABLE_SYNC_MASK) + arch_sync_kernel_mappings(start, end); +} + +static int vmap_pte_range(pmd_t *pmd, unsigned long addr, + unsigned long end, pgprot_t prot, struct page **pages, int *nr, + pgtbl_mod_mask *mask) +{ + pte_t *pte; + + /* + * nr is a running index into the array which helps higher level + * callers keep track of where we're up to. + */ + + pte = pte_alloc_kernel_track(pmd, addr, mask); + if (!pte) + return -ENOMEM; + do { + struct page *page = pages[*nr]; + + if (WARN_ON(!pte_none(*pte))) + return -EBUSY; + if (WARN_ON(!page)) + return -ENOMEM; + set_pte_at(&init_mm, addr, pte, mk_pte(page, prot)); + (*nr)++; + } while (pte++, addr += PAGE_SIZE, addr != end); + *mask |= PGTBL_PTE_MODIFIED; + return 0; +} + +static int vmap_pmd_range(pud_t *pud, unsigned long addr, + unsigned long end, pgprot_t prot, struct page **pages, int *nr, + pgtbl_mod_mask *mask) +{ + pmd_t *pmd; + unsigned long next; + + pmd = pmd_alloc_track(&init_mm, pud, addr, mask); + if (!pmd) + return -ENOMEM; + do { + next = pmd_addr_end(addr, end); + if (vmap_pte_range(pmd, addr, next, prot, pages, nr, mask)) + return -ENOMEM; + } while (pmd++, addr = next, addr != end); + return 0; +} + +static int vmap_pud_range(p4d_t *p4d, unsigned long addr, + unsigned long end, pgprot_t prot, struct page **pages, int *nr, + pgtbl_mod_mask *mask) +{ + pud_t *pud; + unsigned long next; + + pud = pud_alloc_track(&init_mm, p4d, addr, mask); + if (!pud) + return -ENOMEM; + do { + next = pud_addr_end(addr, end); + if (vmap_pmd_range(pud, addr, next, prot, pages, nr, mask)) + return -ENOMEM; + } while (pud++, addr = next, addr != end); + return 0; +} + +static int vmap_p4d_range(pgd_t *pgd, unsigned long addr, + unsigned long end, pgprot_t prot, struct page **pages, int *nr, + pgtbl_mod_mask *mask) +{ + p4d_t *p4d; + unsigned long next; + + p4d = p4d_alloc_track(&init_mm, pgd, addr, mask); + if (!p4d) + return -ENOMEM; + do { + next = p4d_addr_end(addr, end); + if (vmap_pud_range(p4d, addr, next, prot, pages, nr, mask)) + return -ENOMEM; + } while (p4d++, addr = next, addr != end); + return 0; +} + +/** + * map_kernel_range_noflush - map kernel VM area with the specified pages + * @addr: start of the VM area to map + * @size: size of the VM area to map + * @prot: page protection flags to use + * @pages: pages to map + * + * Map PFN_UP(@size) pages at @addr. The VM area @addr and @size specify should + * have been allocated using get_vm_area() and its friends. + * + * NOTE: + * This function does NOT do any cache flushing. The caller is responsible for + * calling flush_cache_vmap() on to-be-mapped areas before calling this + * function. + * + * RETURNS: + * 0 on success, -errno on failure. + */ +int map_kernel_range_noflush(unsigned long addr, unsigned long size, + pgprot_t prot, struct page **pages) +{ + unsigned long start = addr; + unsigned long end = addr + size; + unsigned long next; + pgd_t *pgd; + int err = 0; + int nr = 0; + pgtbl_mod_mask mask = 0; + + BUG_ON(addr >= end); + pgd = pgd_offset_k(addr); + do { + next = pgd_addr_end(addr, end); + if (pgd_bad(*pgd)) + mask |= PGTBL_PGD_MODIFIED; + err = vmap_p4d_range(pgd, addr, next, prot, pages, &nr, &mask); + if (err) + return err; + } while (pgd++, addr = next, addr != end); + + if (mask & ARCH_PAGE_TABLE_SYNC_MASK) + arch_sync_kernel_mappings(start, end); + + return 0; +} + +int map_kernel_range(unsigned long start, unsigned long size, pgprot_t prot, + struct page **pages) +{ + int ret; + + ret = map_kernel_range_noflush(start, size, prot, pages); + flush_cache_vmap(start, start + size); + return ret; +} + +int is_vmalloc_or_module_addr(const void *x) +{ + /* + * ARM, x86-64 and sparc64 put modules in a special place, + * and fall back on vmalloc() if that fails. Others + * just put it in the vmalloc space. + */ +#if defined(CONFIG_MODULES) && defined(MODULES_VADDR) + unsigned long addr = (unsigned long)x; + if (addr >= MODULES_VADDR && addr < MODULES_END) + return 1; +#endif + return is_vmalloc_addr(x); +} + +/* + * Walk a vmap address to the struct page it maps. + */ +struct page *vmalloc_to_page(const void *vmalloc_addr) +{ + unsigned long addr = (unsigned long) vmalloc_addr; + struct page *page = NULL; + pgd_t *pgd = pgd_offset_k(addr); + p4d_t *p4d; + pud_t *pud; + pmd_t *pmd; + pte_t *ptep, pte; + + /* + * XXX we might need to change this if we add VIRTUAL_BUG_ON for + * architectures that do not vmalloc module space + */ + VIRTUAL_BUG_ON(!is_vmalloc_or_module_addr(vmalloc_addr)); + + if (pgd_none(*pgd)) + return NULL; + p4d = p4d_offset(pgd, addr); + if (p4d_none(*p4d)) + return NULL; + pud = pud_offset(p4d, addr); + + /* + * Don't dereference bad PUD or PMD (below) entries. This will also + * identify huge mappings, which we may encounter on architectures + * that define CONFIG_HAVE_ARCH_HUGE_VMAP=y. Such regions will be + * identified as vmalloc addresses by is_vmalloc_addr(), but are + * not [unambiguously] associated with a struct page, so there is + * no correct value to return for them. + */ + WARN_ON_ONCE(pud_bad(*pud)); + if (pud_none(*pud) || pud_bad(*pud)) + return NULL; + pmd = pmd_offset(pud, addr); + WARN_ON_ONCE(pmd_bad(*pmd)); + if (pmd_none(*pmd) || pmd_bad(*pmd)) + return NULL; + + ptep = pte_offset_map(pmd, addr); + pte = *ptep; + if (pte_present(pte)) + page = pte_page(pte); + pte_unmap(ptep); + return page; +} +EXPORT_SYMBOL(vmalloc_to_page); + +/* + * Map a vmalloc()-space virtual address to the physical page frame number. + */ +unsigned long vmalloc_to_pfn(const void *vmalloc_addr) +{ + return page_to_pfn(vmalloc_to_page(vmalloc_addr)); +} +EXPORT_SYMBOL(vmalloc_to_pfn); + + +/*** Global kva allocator ***/ + +#define DEBUG_AUGMENT_PROPAGATE_CHECK 0 +#define DEBUG_AUGMENT_LOWEST_MATCH_CHECK 0 + + +static DEFINE_SPINLOCK(vmap_area_lock); +static DEFINE_SPINLOCK(free_vmap_area_lock); +/* Export for kexec only */ +LIST_HEAD(vmap_area_list); +static LLIST_HEAD(vmap_purge_list); +static struct rb_root vmap_area_root = RB_ROOT; +static bool vmap_initialized __read_mostly; + +/* + * This kmem_cache is used for vmap_area objects. Instead of + * allocating from slab we reuse an object from this cache to + * make things faster. Especially in "no edge" splitting of + * free block. + */ +static struct kmem_cache *vmap_area_cachep; + +/* + * This linked list is used in pair with free_vmap_area_root. + * It gives O(1) access to prev/next to perform fast coalescing. + */ +static LIST_HEAD(free_vmap_area_list); + +/* + * This augment red-black tree represents the free vmap space. + * All vmap_area objects in this tree are sorted by va->va_start + * address. It is used for allocation and merging when a vmap + * object is released. + * + * Each vmap_area node contains a maximum available free block + * of its sub-tree, right or left. Therefore it is possible to + * find a lowest match of free area. + */ +static struct rb_root free_vmap_area_root = RB_ROOT; + +/* + * Preload a CPU with one object for "no edge" split case. The + * aim is to get rid of allocations from the atomic context, thus + * to use more permissive allocation masks. + */ +static DEFINE_PER_CPU(struct vmap_area *, ne_fit_preload_node); + +static __always_inline unsigned long +va_size(struct vmap_area *va) +{ + return (va->va_end - va->va_start); +} + +static __always_inline unsigned long +get_subtree_max_size(struct rb_node *node) +{ + struct vmap_area *va; + + va = rb_entry_safe(node, struct vmap_area, rb_node); + return va ? va->subtree_max_size : 0; +} + +/* + * Gets called when remove the node and rotate. + */ +static __always_inline unsigned long +compute_subtree_max_size(struct vmap_area *va) +{ + return max3(va_size(va), + get_subtree_max_size(va->rb_node.rb_left), + get_subtree_max_size(va->rb_node.rb_right)); +} + +RB_DECLARE_CALLBACKS_MAX(static, free_vmap_area_rb_augment_cb, + struct vmap_area, rb_node, unsigned long, subtree_max_size, va_size) + +static void purge_vmap_area_lazy(void); +static BLOCKING_NOTIFIER_HEAD(vmap_notify_list); +static unsigned long lazy_max_pages(void); + +static atomic_long_t nr_vmalloc_pages; + +unsigned long vmalloc_nr_pages(void) +{ + return atomic_long_read(&nr_vmalloc_pages); +} + +static struct vmap_area *__find_vmap_area(unsigned long addr) +{ + struct rb_node *n = vmap_area_root.rb_node; + + while (n) { + struct vmap_area *va; + + va = rb_entry(n, struct vmap_area, rb_node); + if (addr < va->va_start) + n = n->rb_left; + else if (addr >= va->va_end) + n = n->rb_right; + else + return va; + } + + return NULL; +} + +/* + * This function returns back addresses of parent node + * and its left or right link for further processing. + * + * Otherwise NULL is returned. In that case all further + * steps regarding inserting of conflicting overlap range + * have to be declined and actually considered as a bug. + */ +static __always_inline struct rb_node ** +find_va_links(struct vmap_area *va, + struct rb_root *root, struct rb_node *from, + struct rb_node **parent) +{ + struct vmap_area *tmp_va; + struct rb_node **link; + + if (root) { + link = &root->rb_node; + if (unlikely(!*link)) { + *parent = NULL; + return link; + } + } else { + link = &from; + } + + /* + * Go to the bottom of the tree. When we hit the last point + * we end up with parent rb_node and correct direction, i name + * it link, where the new va->rb_node will be attached to. + */ + do { + tmp_va = rb_entry(*link, struct vmap_area, rb_node); + + /* + * During the traversal we also do some sanity check. + * Trigger the BUG() if there are sides(left/right) + * or full overlaps. + */ + if (va->va_start < tmp_va->va_end && + va->va_end <= tmp_va->va_start) + link = &(*link)->rb_left; + else if (va->va_end > tmp_va->va_start && + va->va_start >= tmp_va->va_end) + link = &(*link)->rb_right; + else { + WARN(1, "vmalloc bug: 0x%lx-0x%lx overlaps with 0x%lx-0x%lx\n", + va->va_start, va->va_end, tmp_va->va_start, tmp_va->va_end); + + return NULL; + } + } while (*link); + + *parent = &tmp_va->rb_node; + return link; +} + +static __always_inline struct list_head * +get_va_next_sibling(struct rb_node *parent, struct rb_node **link) +{ + struct list_head *list; + + if (unlikely(!parent)) + /* + * The red-black tree where we try to find VA neighbors + * before merging or inserting is empty, i.e. it means + * there is no free vmap space. Normally it does not + * happen but we handle this case anyway. + */ + return NULL; + + list = &rb_entry(parent, struct vmap_area, rb_node)->list; + return (&parent->rb_right == link ? list->next : list); +} + +static __always_inline void +link_va(struct vmap_area *va, struct rb_root *root, + struct rb_node *parent, struct rb_node **link, struct list_head *head) +{ + /* + * VA is still not in the list, but we can + * identify its future previous list_head node. + */ + if (likely(parent)) { + head = &rb_entry(parent, struct vmap_area, rb_node)->list; + if (&parent->rb_right != link) + head = head->prev; + } + + /* Insert to the rb-tree */ + rb_link_node(&va->rb_node, parent, link); + if (root == &free_vmap_area_root) { + /* + * Some explanation here. Just perform simple insertion + * to the tree. We do not set va->subtree_max_size to + * its current size before calling rb_insert_augmented(). + * It is because of we populate the tree from the bottom + * to parent levels when the node _is_ in the tree. + * + * Therefore we set subtree_max_size to zero after insertion, + * to let __augment_tree_propagate_from() puts everything to + * the correct order later on. + */ + rb_insert_augmented(&va->rb_node, + root, &free_vmap_area_rb_augment_cb); + va->subtree_max_size = 0; + } else { + rb_insert_color(&va->rb_node, root); + } + + /* Address-sort this list */ + list_add(&va->list, head); +} + +static __always_inline void +unlink_va(struct vmap_area *va, struct rb_root *root) +{ + if (WARN_ON(RB_EMPTY_NODE(&va->rb_node))) + return; + + if (root == &free_vmap_area_root) + rb_erase_augmented(&va->rb_node, + root, &free_vmap_area_rb_augment_cb); + else + rb_erase(&va->rb_node, root); + + list_del(&va->list); + RB_CLEAR_NODE(&va->rb_node); +} + +#if DEBUG_AUGMENT_PROPAGATE_CHECK +static void +augment_tree_propagate_check(void) +{ + struct vmap_area *va; + unsigned long computed_size; + + list_for_each_entry(va, &free_vmap_area_list, list) { + computed_size = compute_subtree_max_size(va); + if (computed_size != va->subtree_max_size) + pr_emerg("tree is corrupted: %lu, %lu\n", + va_size(va), va->subtree_max_size); + } +} +#endif + +/* + * This function populates subtree_max_size from bottom to upper + * levels starting from VA point. The propagation must be done + * when VA size is modified by changing its va_start/va_end. Or + * in case of newly inserting of VA to the tree. + * + * It means that __augment_tree_propagate_from() must be called: + * - After VA has been inserted to the tree(free path); + * - After VA has been shrunk(allocation path); + * - After VA has been increased(merging path). + * + * Please note that, it does not mean that upper parent nodes + * and their subtree_max_size are recalculated all the time up + * to the root node. + * + * 4--8 + * /\ + * / \ + * / \ + * 2--2 8--8 + * + * For example if we modify the node 4, shrinking it to 2, then + * no any modification is required. If we shrink the node 2 to 1 + * its subtree_max_size is updated only, and set to 1. If we shrink + * the node 8 to 6, then its subtree_max_size is set to 6 and parent + * node becomes 4--6. + */ +static __always_inline void +augment_tree_propagate_from(struct vmap_area *va) +{ + /* + * Populate the tree from bottom towards the root until + * the calculated maximum available size of checked node + * is equal to its current one. + */ + free_vmap_area_rb_augment_cb_propagate(&va->rb_node, NULL); + +#if DEBUG_AUGMENT_PROPAGATE_CHECK + augment_tree_propagate_check(); +#endif +} + +static void +insert_vmap_area(struct vmap_area *va, + struct rb_root *root, struct list_head *head) +{ + struct rb_node **link; + struct rb_node *parent; + + link = find_va_links(va, root, NULL, &parent); + if (link) + link_va(va, root, parent, link, head); +} + +static void +insert_vmap_area_augment(struct vmap_area *va, + struct rb_node *from, struct rb_root *root, + struct list_head *head) +{ + struct rb_node **link; + struct rb_node *parent; + + if (from) + link = find_va_links(va, NULL, from, &parent); + else + link = find_va_links(va, root, NULL, &parent); + + if (link) { + link_va(va, root, parent, link, head); + augment_tree_propagate_from(va); + } +} + +/* + * Merge de-allocated chunk of VA memory with previous + * and next free blocks. If coalesce is not done a new + * free area is inserted. If VA has been merged, it is + * freed. + * + * Please note, it can return NULL in case of overlap + * ranges, followed by WARN() report. Despite it is a + * buggy behaviour, a system can be alive and keep + * ongoing. + */ +static __always_inline struct vmap_area * +merge_or_add_vmap_area(struct vmap_area *va, + struct rb_root *root, struct list_head *head) +{ + struct vmap_area *sibling; + struct list_head *next; + struct rb_node **link; + struct rb_node *parent; + bool merged = false; + + /* + * Find a place in the tree where VA potentially will be + * inserted, unless it is merged with its sibling/siblings. + */ + link = find_va_links(va, root, NULL, &parent); + if (!link) + return NULL; + + /* + * Get next node of VA to check if merging can be done. + */ + next = get_va_next_sibling(parent, link); + if (unlikely(next == NULL)) + goto insert; + + /* + * start end + * | | + * |<------VA------>|<-----Next----->| + * | | + * start end + */ + if (next != head) { + sibling = list_entry(next, struct vmap_area, list); + if (sibling->va_start == va->va_end) { + sibling->va_start = va->va_start; + + /* Free vmap_area object. */ + kmem_cache_free(vmap_area_cachep, va); + + /* Point to the new merged area. */ + va = sibling; + merged = true; + } + } + + /* + * start end + * | | + * |<-----Prev----->|<------VA------>| + * | | + * start end + */ + if (next->prev != head) { + sibling = list_entry(next->prev, struct vmap_area, list); + if (sibling->va_end == va->va_start) { + /* + * If both neighbors are coalesced, it is important + * to unlink the "next" node first, followed by merging + * with "previous" one. Otherwise the tree might not be + * fully populated if a sibling's augmented value is + * "normalized" because of rotation operations. + */ + if (merged) + unlink_va(va, root); + + sibling->va_end = va->va_end; + + /* Free vmap_area object. */ + kmem_cache_free(vmap_area_cachep, va); + + /* Point to the new merged area. */ + va = sibling; + merged = true; + } + } + +insert: + if (!merged) + link_va(va, root, parent, link, head); + + /* + * Last step is to check and update the tree. + */ + augment_tree_propagate_from(va); + return va; +} + +static __always_inline bool +is_within_this_va(struct vmap_area *va, unsigned long size, + unsigned long align, unsigned long vstart) +{ + unsigned long nva_start_addr; + + if (va->va_start > vstart) + nva_start_addr = ALIGN(va->va_start, align); + else + nva_start_addr = ALIGN(vstart, align); + + /* Can be overflowed due to big size or alignment. */ + if (nva_start_addr + size < nva_start_addr || + nva_start_addr < vstart) + return false; + + return (nva_start_addr + size <= va->va_end); +} + +/* + * Find the first free block(lowest start address) in the tree, + * that will accomplish the request corresponding to passing + * parameters. + */ +static __always_inline struct vmap_area * +find_vmap_lowest_match(unsigned long size, + unsigned long align, unsigned long vstart) +{ + struct vmap_area *va; + struct rb_node *node; + unsigned long length; + + /* Start from the root. */ + node = free_vmap_area_root.rb_node; + + /* Adjust the search size for alignment overhead. */ + length = size + align - 1; + + while (node) { + va = rb_entry(node, struct vmap_area, rb_node); + + if (get_subtree_max_size(node->rb_left) >= length && + vstart < va->va_start) { + node = node->rb_left; + } else { + if (is_within_this_va(va, size, align, vstart)) + return va; + + /* + * Does not make sense to go deeper towards the right + * sub-tree if it does not have a free block that is + * equal or bigger to the requested search length. + */ + if (get_subtree_max_size(node->rb_right) >= length) { + node = node->rb_right; + continue; + } + + /* + * OK. We roll back and find the first right sub-tree, + * that will satisfy the search criteria. It can happen + * only once due to "vstart" restriction. + */ + while ((node = rb_parent(node))) { + va = rb_entry(node, struct vmap_area, rb_node); + if (is_within_this_va(va, size, align, vstart)) + return va; + + if (get_subtree_max_size(node->rb_right) >= length && + vstart <= va->va_start) { + node = node->rb_right; + break; + } + } + } + } + + return NULL; +} + +#if DEBUG_AUGMENT_LOWEST_MATCH_CHECK +#include <linux/random.h> + +static struct vmap_area * +find_vmap_lowest_linear_match(unsigned long size, + unsigned long align, unsigned long vstart) +{ + struct vmap_area *va; + + list_for_each_entry(va, &free_vmap_area_list, list) { + if (!is_within_this_va(va, size, align, vstart)) + continue; + + return va; + } + + return NULL; +} + +static void +find_vmap_lowest_match_check(unsigned long size) +{ + struct vmap_area *va_1, *va_2; + unsigned long vstart; + unsigned int rnd; + + get_random_bytes(&rnd, sizeof(rnd)); + vstart = VMALLOC_START + rnd; + + va_1 = find_vmap_lowest_match(size, 1, vstart); + va_2 = find_vmap_lowest_linear_match(size, 1, vstart); + + if (va_1 != va_2) + pr_emerg("not lowest: t: 0x%p, l: 0x%p, v: 0x%lx\n", + va_1, va_2, vstart); +} +#endif + +enum fit_type { + NOTHING_FIT = 0, + FL_FIT_TYPE = 1, /* full fit */ + LE_FIT_TYPE = 2, /* left edge fit */ + RE_FIT_TYPE = 3, /* right edge fit */ + NE_FIT_TYPE = 4 /* no edge fit */ +}; + +static __always_inline enum fit_type +classify_va_fit_type(struct vmap_area *va, + unsigned long nva_start_addr, unsigned long size) +{ + enum fit_type type; + + /* Check if it is within VA. */ + if (nva_start_addr < va->va_start || + nva_start_addr + size > va->va_end) + return NOTHING_FIT; + + /* Now classify. */ + if (va->va_start == nva_start_addr) { + if (va->va_end == nva_start_addr + size) + type = FL_FIT_TYPE; + else + type = LE_FIT_TYPE; + } else if (va->va_end == nva_start_addr + size) { + type = RE_FIT_TYPE; + } else { + type = NE_FIT_TYPE; + } + + return type; +} + +static __always_inline int +adjust_va_to_fit_type(struct vmap_area *va, + unsigned long nva_start_addr, unsigned long size, + enum fit_type type) +{ + struct vmap_area *lva = NULL; + + if (type == FL_FIT_TYPE) { + /* + * No need to split VA, it fully fits. + * + * | | + * V NVA V + * |---------------| + */ + unlink_va(va, &free_vmap_area_root); + kmem_cache_free(vmap_area_cachep, va); + } else if (type == LE_FIT_TYPE) { + /* + * Split left edge of fit VA. + * + * | | + * V NVA V R + * |-------|-------| + */ + va->va_start += size; + } else if (type == RE_FIT_TYPE) { + /* + * Split right edge of fit VA. + * + * | | + * L V NVA V + * |-------|-------| + */ + va->va_end = nva_start_addr; + } else if (type == NE_FIT_TYPE) { + /* + * Split no edge of fit VA. + * + * | | + * L V NVA V R + * |---|-------|---| + */ + lva = __this_cpu_xchg(ne_fit_preload_node, NULL); + if (unlikely(!lva)) { + /* + * For percpu allocator we do not do any pre-allocation + * and leave it as it is. The reason is it most likely + * never ends up with NE_FIT_TYPE splitting. In case of + * percpu allocations offsets and sizes are aligned to + * fixed align request, i.e. RE_FIT_TYPE and FL_FIT_TYPE + * are its main fitting cases. + * + * There are a few exceptions though, as an example it is + * a first allocation (early boot up) when we have "one" + * big free space that has to be split. + * + * Also we can hit this path in case of regular "vmap" + * allocations, if "this" current CPU was not preloaded. + * See the comment in alloc_vmap_area() why. If so, then + * GFP_NOWAIT is used instead to get an extra object for + * split purpose. That is rare and most time does not + * occur. + * + * What happens if an allocation gets failed. Basically, + * an "overflow" path is triggered to purge lazily freed + * areas to free some memory, then, the "retry" path is + * triggered to repeat one more time. See more details + * in alloc_vmap_area() function. + */ + lva = kmem_cache_alloc(vmap_area_cachep, GFP_NOWAIT); + if (!lva) + return -1; + } + + /* + * Build the remainder. + */ + lva->va_start = va->va_start; + lva->va_end = nva_start_addr; + + /* + * Shrink this VA to remaining size. + */ + va->va_start = nva_start_addr + size; + } else { + return -1; + } + + if (type != FL_FIT_TYPE) { + augment_tree_propagate_from(va); + + if (lva) /* type == NE_FIT_TYPE */ + insert_vmap_area_augment(lva, &va->rb_node, + &free_vmap_area_root, &free_vmap_area_list); + } + + return 0; +} + +/* + * Returns a start address of the newly allocated area, if success. + * Otherwise a vend is returned that indicates failure. + */ +static __always_inline unsigned long +__alloc_vmap_area(unsigned long size, unsigned long align, + unsigned long vstart, unsigned long vend) +{ + unsigned long nva_start_addr; + struct vmap_area *va; + enum fit_type type; + int ret; + + va = find_vmap_lowest_match(size, align, vstart); + if (unlikely(!va)) + return vend; + + if (va->va_start > vstart) + nva_start_addr = ALIGN(va->va_start, align); + else + nva_start_addr = ALIGN(vstart, align); + + /* Check the "vend" restriction. */ + if (nva_start_addr + size > vend) + return vend; + + /* Classify what we have found. */ + type = classify_va_fit_type(va, nva_start_addr, size); + if (WARN_ON_ONCE(type == NOTHING_FIT)) + return vend; + + /* Update the free vmap_area. */ + ret = adjust_va_to_fit_type(va, nva_start_addr, size, type); + if (ret) + return vend; + +#if DEBUG_AUGMENT_LOWEST_MATCH_CHECK + find_vmap_lowest_match_check(size); +#endif + + return nva_start_addr; +} + +/* + * Free a region of KVA allocated by alloc_vmap_area + */ +static void free_vmap_area(struct vmap_area *va) +{ + /* + * Remove from the busy tree/list. + */ + spin_lock(&vmap_area_lock); + unlink_va(va, &vmap_area_root); + spin_unlock(&vmap_area_lock); + + /* + * Insert/Merge it back to the free tree/list. + */ + spin_lock(&free_vmap_area_lock); + merge_or_add_vmap_area(va, &free_vmap_area_root, &free_vmap_area_list); + spin_unlock(&free_vmap_area_lock); +} + +/* + * Allocate a region of KVA of the specified size and alignment, within the + * vstart and vend. + */ +static struct vmap_area *alloc_vmap_area(unsigned long size, + unsigned long align, + unsigned long vstart, unsigned long vend, + int node, gfp_t gfp_mask) +{ + struct vmap_area *va, *pva; + unsigned long addr; + int purged = 0; + int ret; + + BUG_ON(!size); + BUG_ON(offset_in_page(size)); + BUG_ON(!is_power_of_2(align)); + + if (unlikely(!vmap_initialized)) + return ERR_PTR(-EBUSY); + + might_sleep(); + gfp_mask = gfp_mask & GFP_RECLAIM_MASK; + + va = kmem_cache_alloc_node(vmap_area_cachep, gfp_mask, node); + if (unlikely(!va)) + return ERR_PTR(-ENOMEM); + + /* + * Only scan the relevant parts containing pointers to other objects + * to avoid false negatives. + */ + kmemleak_scan_area(&va->rb_node, SIZE_MAX, gfp_mask); + +retry: + /* + * Preload this CPU with one extra vmap_area object. It is used + * when fit type of free area is NE_FIT_TYPE. Please note, it + * does not guarantee that an allocation occurs on a CPU that + * is preloaded, instead we minimize the case when it is not. + * It can happen because of cpu migration, because there is a + * race until the below spinlock is taken. + * + * The preload is done in non-atomic context, thus it allows us + * to use more permissive allocation masks to be more stable under + * low memory condition and high memory pressure. In rare case, + * if not preloaded, GFP_NOWAIT is used. + * + * Set "pva" to NULL here, because of "retry" path. + */ + pva = NULL; + + if (!this_cpu_read(ne_fit_preload_node)) + /* + * Even if it fails we do not really care about that. + * Just proceed as it is. If needed "overflow" path + * will refill the cache we allocate from. + */ + pva = kmem_cache_alloc_node(vmap_area_cachep, gfp_mask, node); + + spin_lock(&free_vmap_area_lock); + + if (pva && __this_cpu_cmpxchg(ne_fit_preload_node, NULL, pva)) + kmem_cache_free(vmap_area_cachep, pva); + + /* + * If an allocation fails, the "vend" address is + * returned. Therefore trigger the overflow path. + */ + addr = __alloc_vmap_area(size, align, vstart, vend); + spin_unlock(&free_vmap_area_lock); + + if (unlikely(addr == vend)) + goto overflow; + + va->va_start = addr; + va->va_end = addr + size; + va->vm = NULL; + + + spin_lock(&vmap_area_lock); + insert_vmap_area(va, &vmap_area_root, &vmap_area_list); + spin_unlock(&vmap_area_lock); + + BUG_ON(!IS_ALIGNED(va->va_start, align)); + BUG_ON(va->va_start < vstart); + BUG_ON(va->va_end > vend); + + ret = kasan_populate_vmalloc(addr, size); + if (ret) { + free_vmap_area(va); + return ERR_PTR(ret); + } + + return va; + +overflow: + if (!purged) { + purge_vmap_area_lazy(); + purged = 1; + goto retry; + } + + if (gfpflags_allow_blocking(gfp_mask)) { + unsigned long freed = 0; + blocking_notifier_call_chain(&vmap_notify_list, 0, &freed); + if (freed > 0) { + purged = 0; + goto retry; + } + } + + if (!(gfp_mask & __GFP_NOWARN) && printk_ratelimit()) + pr_warn("vmap allocation for size %lu failed: use vmalloc=<size> to increase size\n", + size); + + kmem_cache_free(vmap_area_cachep, va); + return ERR_PTR(-EBUSY); +} + +int register_vmap_purge_notifier(struct notifier_block *nb) +{ + return blocking_notifier_chain_register(&vmap_notify_list, nb); +} +EXPORT_SYMBOL_GPL(register_vmap_purge_notifier); + +int unregister_vmap_purge_notifier(struct notifier_block *nb) +{ + return blocking_notifier_chain_unregister(&vmap_notify_list, nb); +} +EXPORT_SYMBOL_GPL(unregister_vmap_purge_notifier); + +/* + * lazy_max_pages is the maximum amount of virtual address space we gather up + * before attempting to purge with a TLB flush. + * + * There is a tradeoff here: a larger number will cover more kernel page tables + * and take slightly longer to purge, but it will linearly reduce the number of + * global TLB flushes that must be performed. It would seem natural to scale + * this number up linearly with the number of CPUs (because vmapping activity + * could also scale linearly with the number of CPUs), however it is likely + * that in practice, workloads might be constrained in other ways that mean + * vmap activity will not scale linearly with CPUs. Also, I want to be + * conservative and not introduce a big latency on huge systems, so go with + * a less aggressive log scale. It will still be an improvement over the old + * code, and it will be simple to change the scale factor if we find that it + * becomes a problem on bigger systems. + */ +static unsigned long lazy_max_pages(void) +{ + unsigned int log; + + log = fls(num_online_cpus()); + + return log * (32UL * 1024 * 1024 / PAGE_SIZE); +} + +static atomic_long_t vmap_lazy_nr = ATOMIC_LONG_INIT(0); + +/* + * Serialize vmap purging. There is no actual criticial section protected + * by this look, but we want to avoid concurrent calls for performance + * reasons and to make the pcpu_get_vm_areas more deterministic. + */ +static DEFINE_MUTEX(vmap_purge_lock); + +/* for per-CPU blocks */ +static void purge_fragmented_blocks_allcpus(void); + +/* + * called before a call to iounmap() if the caller wants vm_area_struct's + * immediately freed. + */ +void set_iounmap_nonlazy(void) +{ + atomic_long_set(&vmap_lazy_nr, lazy_max_pages()+1); +} + +/* + * Purges all lazily-freed vmap areas. + */ +static bool __purge_vmap_area_lazy(unsigned long start, unsigned long end) +{ + unsigned long resched_threshold; + struct llist_node *valist; + struct vmap_area *va; + struct vmap_area *n_va; + + lockdep_assert_held(&vmap_purge_lock); + + valist = llist_del_all(&vmap_purge_list); + if (unlikely(valist == NULL)) + return false; + + /* + * TODO: to calculate a flush range without looping. + * The list can be up to lazy_max_pages() elements. + */ + llist_for_each_entry(va, valist, purge_list) { + if (va->va_start < start) + start = va->va_start; + if (va->va_end > end) + end = va->va_end; + } + + flush_tlb_kernel_range(start, end); + resched_threshold = lazy_max_pages() << 1; + + spin_lock(&free_vmap_area_lock); + llist_for_each_entry_safe(va, n_va, valist, purge_list) { + unsigned long nr = (va->va_end - va->va_start) >> PAGE_SHIFT; + unsigned long orig_start = va->va_start; + unsigned long orig_end = va->va_end; + + /* + * Finally insert or merge lazily-freed area. It is + * detached and there is no need to "unlink" it from + * anything. + */ + va = merge_or_add_vmap_area(va, &free_vmap_area_root, + &free_vmap_area_list); + + if (!va) + continue; + + if (is_vmalloc_or_module_addr((void *)orig_start)) + kasan_release_vmalloc(orig_start, orig_end, + va->va_start, va->va_end); + + atomic_long_sub(nr, &vmap_lazy_nr); + + if (atomic_long_read(&vmap_lazy_nr) < resched_threshold) + cond_resched_lock(&free_vmap_area_lock); + } + spin_unlock(&free_vmap_area_lock); + return true; +} + +/* + * Kick off a purge of the outstanding lazy areas. Don't bother if somebody + * is already purging. + */ +static void try_purge_vmap_area_lazy(void) +{ + if (mutex_trylock(&vmap_purge_lock)) { + __purge_vmap_area_lazy(ULONG_MAX, 0); + mutex_unlock(&vmap_purge_lock); + } +} + +/* + * Kick off a purge of the outstanding lazy areas. + */ +static void purge_vmap_area_lazy(void) +{ + mutex_lock(&vmap_purge_lock); + purge_fragmented_blocks_allcpus(); + __purge_vmap_area_lazy(ULONG_MAX, 0); + mutex_unlock(&vmap_purge_lock); +} + +/* + * Free a vmap area, caller ensuring that the area has been unmapped + * and flush_cache_vunmap had been called for the correct range + * previously. + */ +static void free_vmap_area_noflush(struct vmap_area *va) +{ + unsigned long nr_lazy; + + spin_lock(&vmap_area_lock); + unlink_va(va, &vmap_area_root); + spin_unlock(&vmap_area_lock); + + nr_lazy = atomic_long_add_return((va->va_end - va->va_start) >> + PAGE_SHIFT, &vmap_lazy_nr); + + /* After this point, we may free va at any time */ + llist_add(&va->purge_list, &vmap_purge_list); + + if (unlikely(nr_lazy > lazy_max_pages())) + try_purge_vmap_area_lazy(); +} + +/* + * Free and unmap a vmap area + */ +static void free_unmap_vmap_area(struct vmap_area *va) +{ + flush_cache_vunmap(va->va_start, va->va_end); + unmap_kernel_range_noflush(va->va_start, va->va_end - va->va_start); + if (debug_pagealloc_enabled_static()) + flush_tlb_kernel_range(va->va_start, va->va_end); + + free_vmap_area_noflush(va); +} + +static struct vmap_area *find_vmap_area(unsigned long addr) +{ + struct vmap_area *va; + + spin_lock(&vmap_area_lock); + va = __find_vmap_area(addr); + spin_unlock(&vmap_area_lock); + + return va; +} + +/*** Per cpu kva allocator ***/ + +/* + * vmap space is limited especially on 32 bit architectures. Ensure there is + * room for at least 16 percpu vmap blocks per CPU. + */ +/* + * If we had a constant VMALLOC_START and VMALLOC_END, we'd like to be able + * to #define VMALLOC_SPACE (VMALLOC_END-VMALLOC_START). Guess + * instead (we just need a rough idea) + */ +#if BITS_PER_LONG == 32 +#define VMALLOC_SPACE (128UL*1024*1024) +#else +#define VMALLOC_SPACE (128UL*1024*1024*1024) +#endif + +#define VMALLOC_PAGES (VMALLOC_SPACE / PAGE_SIZE) +#define VMAP_MAX_ALLOC BITS_PER_LONG /* 256K with 4K pages */ +#define VMAP_BBMAP_BITS_MAX 1024 /* 4MB with 4K pages */ +#define VMAP_BBMAP_BITS_MIN (VMAP_MAX_ALLOC*2) +#define VMAP_MIN(x, y) ((x) < (y) ? (x) : (y)) /* can't use min() */ +#define VMAP_MAX(x, y) ((x) > (y) ? (x) : (y)) /* can't use max() */ +#define VMAP_BBMAP_BITS \ + VMAP_MIN(VMAP_BBMAP_BITS_MAX, \ + VMAP_MAX(VMAP_BBMAP_BITS_MIN, \ + VMALLOC_PAGES / roundup_pow_of_two(NR_CPUS) / 16)) + +#define VMAP_BLOCK_SIZE (VMAP_BBMAP_BITS * PAGE_SIZE) + +struct vmap_block_queue { + spinlock_t lock; + struct list_head free; +}; + +struct vmap_block { + spinlock_t lock; + struct vmap_area *va; + unsigned long free, dirty; + unsigned long dirty_min, dirty_max; /*< dirty range */ + struct list_head free_list; + struct rcu_head rcu_head; + struct list_head purge; +}; + +/* Queue of free and dirty vmap blocks, for allocation and flushing purposes */ +static DEFINE_PER_CPU(struct vmap_block_queue, vmap_block_queue); + +/* + * XArray of vmap blocks, indexed by address, to quickly find a vmap block + * in the free path. Could get rid of this if we change the API to return a + * "cookie" from alloc, to be passed to free. But no big deal yet. + */ +static DEFINE_XARRAY(vmap_blocks); + +/* + * We should probably have a fallback mechanism to allocate virtual memory + * out of partially filled vmap blocks. However vmap block sizing should be + * fairly reasonable according to the vmalloc size, so it shouldn't be a + * big problem. + */ + +static unsigned long addr_to_vb_idx(unsigned long addr) +{ + addr -= VMALLOC_START & ~(VMAP_BLOCK_SIZE-1); + addr /= VMAP_BLOCK_SIZE; + return addr; +} + +static void *vmap_block_vaddr(unsigned long va_start, unsigned long pages_off) +{ + unsigned long addr; + + addr = va_start + (pages_off << PAGE_SHIFT); + BUG_ON(addr_to_vb_idx(addr) != addr_to_vb_idx(va_start)); + return (void *)addr; +} + +/** + * new_vmap_block - allocates new vmap_block and occupies 2^order pages in this + * block. Of course pages number can't exceed VMAP_BBMAP_BITS + * @order: how many 2^order pages should be occupied in newly allocated block + * @gfp_mask: flags for the page level allocator + * + * Return: virtual address in a newly allocated block or ERR_PTR(-errno) + */ +static void *new_vmap_block(unsigned int order, gfp_t gfp_mask) +{ + struct vmap_block_queue *vbq; + struct vmap_block *vb; + struct vmap_area *va; + unsigned long vb_idx; + int node, err; + void *vaddr; + + node = numa_node_id(); + + vb = kmalloc_node(sizeof(struct vmap_block), + gfp_mask & GFP_RECLAIM_MASK, node); + if (unlikely(!vb)) + return ERR_PTR(-ENOMEM); + + va = alloc_vmap_area(VMAP_BLOCK_SIZE, VMAP_BLOCK_SIZE, + VMALLOC_START, VMALLOC_END, + node, gfp_mask); + if (IS_ERR(va)) { + kfree(vb); + return ERR_CAST(va); + } + + vaddr = vmap_block_vaddr(va->va_start, 0); + spin_lock_init(&vb->lock); + vb->va = va; + /* At least something should be left free */ + BUG_ON(VMAP_BBMAP_BITS <= (1UL << order)); + vb->free = VMAP_BBMAP_BITS - (1UL << order); + vb->dirty = 0; + vb->dirty_min = VMAP_BBMAP_BITS; + vb->dirty_max = 0; + INIT_LIST_HEAD(&vb->free_list); + + vb_idx = addr_to_vb_idx(va->va_start); + err = xa_insert(&vmap_blocks, vb_idx, vb, gfp_mask); + if (err) { + kfree(vb); + free_vmap_area(va); + return ERR_PTR(err); + } + + vbq = &get_cpu_var(vmap_block_queue); + spin_lock(&vbq->lock); + list_add_tail_rcu(&vb->free_list, &vbq->free); + spin_unlock(&vbq->lock); + put_cpu_var(vmap_block_queue); + + return vaddr; +} + +static void free_vmap_block(struct vmap_block *vb) +{ + struct vmap_block *tmp; + + tmp = xa_erase(&vmap_blocks, addr_to_vb_idx(vb->va->va_start)); + BUG_ON(tmp != vb); + + free_vmap_area_noflush(vb->va); + kfree_rcu(vb, rcu_head); +} + +static void purge_fragmented_blocks(int cpu) +{ + LIST_HEAD(purge); + struct vmap_block *vb; + struct vmap_block *n_vb; + struct vmap_block_queue *vbq = &per_cpu(vmap_block_queue, cpu); + + rcu_read_lock(); + list_for_each_entry_rcu(vb, &vbq->free, free_list) { + + if (!(vb->free + vb->dirty == VMAP_BBMAP_BITS && vb->dirty != VMAP_BBMAP_BITS)) + continue; + + spin_lock(&vb->lock); + if (vb->free + vb->dirty == VMAP_BBMAP_BITS && vb->dirty != VMAP_BBMAP_BITS) { + vb->free = 0; /* prevent further allocs after releasing lock */ + vb->dirty = VMAP_BBMAP_BITS; /* prevent purging it again */ + vb->dirty_min = 0; + vb->dirty_max = VMAP_BBMAP_BITS; + spin_lock(&vbq->lock); + list_del_rcu(&vb->free_list); + spin_unlock(&vbq->lock); + spin_unlock(&vb->lock); + list_add_tail(&vb->purge, &purge); + } else + spin_unlock(&vb->lock); + } + rcu_read_unlock(); + + list_for_each_entry_safe(vb, n_vb, &purge, purge) { + list_del(&vb->purge); + free_vmap_block(vb); + } +} + +static void purge_fragmented_blocks_allcpus(void) +{ + int cpu; + + for_each_possible_cpu(cpu) + purge_fragmented_blocks(cpu); +} + +static void *vb_alloc(unsigned long size, gfp_t gfp_mask) +{ + struct vmap_block_queue *vbq; + struct vmap_block *vb; + void *vaddr = NULL; + unsigned int order; + + BUG_ON(offset_in_page(size)); + BUG_ON(size > PAGE_SIZE*VMAP_MAX_ALLOC); + if (WARN_ON(size == 0)) { + /* + * Allocating 0 bytes isn't what caller wants since + * get_order(0) returns funny result. Just warn and terminate + * early. + */ + return NULL; + } + order = get_order(size); + + rcu_read_lock(); + vbq = &get_cpu_var(vmap_block_queue); + list_for_each_entry_rcu(vb, &vbq->free, free_list) { + unsigned long pages_off; + + spin_lock(&vb->lock); + if (vb->free < (1UL << order)) { + spin_unlock(&vb->lock); + continue; + } + + pages_off = VMAP_BBMAP_BITS - vb->free; + vaddr = vmap_block_vaddr(vb->va->va_start, pages_off); + vb->free -= 1UL << order; + if (vb->free == 0) { + spin_lock(&vbq->lock); + list_del_rcu(&vb->free_list); + spin_unlock(&vbq->lock); + } + + spin_unlock(&vb->lock); + break; + } + + put_cpu_var(vmap_block_queue); + rcu_read_unlock(); + + /* Allocate new block if nothing was found */ + if (!vaddr) + vaddr = new_vmap_block(order, gfp_mask); + + return vaddr; +} + +static void vb_free(unsigned long addr, unsigned long size) +{ + unsigned long offset; + unsigned int order; + struct vmap_block *vb; + + BUG_ON(offset_in_page(size)); + BUG_ON(size > PAGE_SIZE*VMAP_MAX_ALLOC); + + flush_cache_vunmap(addr, addr + size); + + order = get_order(size); + offset = (addr & (VMAP_BLOCK_SIZE - 1)) >> PAGE_SHIFT; + vb = xa_load(&vmap_blocks, addr_to_vb_idx(addr)); + + unmap_kernel_range_noflush(addr, size); + + if (debug_pagealloc_enabled_static()) + flush_tlb_kernel_range(addr, addr + size); + + spin_lock(&vb->lock); + + /* Expand dirty range */ + vb->dirty_min = min(vb->dirty_min, offset); + vb->dirty_max = max(vb->dirty_max, offset + (1UL << order)); + + vb->dirty += 1UL << order; + if (vb->dirty == VMAP_BBMAP_BITS) { + BUG_ON(vb->free); + spin_unlock(&vb->lock); + free_vmap_block(vb); + } else + spin_unlock(&vb->lock); +} + +static void _vm_unmap_aliases(unsigned long start, unsigned long end, int flush) +{ + int cpu; + + if (unlikely(!vmap_initialized)) + return; + + might_sleep(); + + for_each_possible_cpu(cpu) { + struct vmap_block_queue *vbq = &per_cpu(vmap_block_queue, cpu); + struct vmap_block *vb; + + rcu_read_lock(); + list_for_each_entry_rcu(vb, &vbq->free, free_list) { + spin_lock(&vb->lock); + if (vb->dirty) { + unsigned long va_start = vb->va->va_start; + unsigned long s, e; + + s = va_start + (vb->dirty_min << PAGE_SHIFT); + e = va_start + (vb->dirty_max << PAGE_SHIFT); + + start = min(s, start); + end = max(e, end); + + flush = 1; + } + spin_unlock(&vb->lock); + } + rcu_read_unlock(); + } + + mutex_lock(&vmap_purge_lock); + purge_fragmented_blocks_allcpus(); + if (!__purge_vmap_area_lazy(start, end) && flush) + flush_tlb_kernel_range(start, end); + mutex_unlock(&vmap_purge_lock); +} + +/** + * vm_unmap_aliases - unmap outstanding lazy aliases in the vmap layer + * + * The vmap/vmalloc layer lazily flushes kernel virtual mappings primarily + * to amortize TLB flushing overheads. What this means is that any page you + * have now, may, in a former life, have been mapped into kernel virtual + * address by the vmap layer and so there might be some CPUs with TLB entries + * still referencing that page (additional to the regular 1:1 kernel mapping). + * + * vm_unmap_aliases flushes all such lazy mappings. After it returns, we can + * be sure that none of the pages we have control over will have any aliases + * from the vmap layer. + */ +void vm_unmap_aliases(void) +{ + unsigned long start = ULONG_MAX, end = 0; + int flush = 0; + + _vm_unmap_aliases(start, end, flush); +} +EXPORT_SYMBOL_GPL(vm_unmap_aliases); + +/** + * vm_unmap_ram - unmap linear kernel address space set up by vm_map_ram + * @mem: the pointer returned by vm_map_ram + * @count: the count passed to that vm_map_ram call (cannot unmap partial) + */ +void vm_unmap_ram(const void *mem, unsigned int count) +{ + unsigned long size = (unsigned long)count << PAGE_SHIFT; + unsigned long addr = (unsigned long)mem; + struct vmap_area *va; + + might_sleep(); + BUG_ON(!addr); + BUG_ON(addr < VMALLOC_START); + BUG_ON(addr > VMALLOC_END); + BUG_ON(!PAGE_ALIGNED(addr)); + + kasan_poison_vmalloc(mem, size); + + if (likely(count <= VMAP_MAX_ALLOC)) { + debug_check_no_locks_freed(mem, size); + vb_free(addr, size); + return; + } + + va = find_vmap_area(addr); + BUG_ON(!va); + debug_check_no_locks_freed((void *)va->va_start, + (va->va_end - va->va_start)); + free_unmap_vmap_area(va); +} +EXPORT_SYMBOL(vm_unmap_ram); + +/** + * vm_map_ram - map pages linearly into kernel virtual address (vmalloc space) + * @pages: an array of pointers to the pages to be mapped + * @count: number of pages + * @node: prefer to allocate data structures on this node + * + * If you use this function for less than VMAP_MAX_ALLOC pages, it could be + * faster than vmap so it's good. But if you mix long-life and short-life + * objects with vm_map_ram(), it could consume lots of address space through + * fragmentation (especially on a 32bit machine). You could see failures in + * the end. Please use this function for short-lived objects. + * + * Returns: a pointer to the address that has been mapped, or %NULL on failure + */ +void *vm_map_ram(struct page **pages, unsigned int count, int node) +{ + unsigned long size = (unsigned long)count << PAGE_SHIFT; + unsigned long addr; + void *mem; + + if (likely(count <= VMAP_MAX_ALLOC)) { + mem = vb_alloc(size, GFP_KERNEL); + if (IS_ERR(mem)) + return NULL; + addr = (unsigned long)mem; + } else { + struct vmap_area *va; + va = alloc_vmap_area(size, PAGE_SIZE, + VMALLOC_START, VMALLOC_END, node, GFP_KERNEL); + if (IS_ERR(va)) + return NULL; + + addr = va->va_start; + mem = (void *)addr; + } + + kasan_unpoison_vmalloc(mem, size); + + if (map_kernel_range(addr, size, PAGE_KERNEL, pages) < 0) { + vm_unmap_ram(mem, count); + return NULL; + } + return mem; +} +EXPORT_SYMBOL(vm_map_ram); + +static struct vm_struct *vmlist __initdata; + +/** + * vm_area_add_early - add vmap area early during boot + * @vm: vm_struct to add + * + * This function is used to add fixed kernel vm area to vmlist before + * vmalloc_init() is called. @vm->addr, @vm->size, and @vm->flags + * should contain proper values and the other fields should be zero. + * + * DO NOT USE THIS FUNCTION UNLESS YOU KNOW WHAT YOU'RE DOING. + */ +void __init vm_area_add_early(struct vm_struct *vm) +{ + struct vm_struct *tmp, **p; + + BUG_ON(vmap_initialized); + for (p = &vmlist; (tmp = *p) != NULL; p = &tmp->next) { + if (tmp->addr >= vm->addr) { + BUG_ON(tmp->addr < vm->addr + vm->size); + break; + } else + BUG_ON(tmp->addr + tmp->size > vm->addr); + } + vm->next = *p; + *p = vm; +} + +/** + * vm_area_register_early - register vmap area early during boot + * @vm: vm_struct to register + * @align: requested alignment + * + * This function is used to register kernel vm area before + * vmalloc_init() is called. @vm->size and @vm->flags should contain + * proper values on entry and other fields should be zero. On return, + * vm->addr contains the allocated address. + * + * DO NOT USE THIS FUNCTION UNLESS YOU KNOW WHAT YOU'RE DOING. + */ +void __init vm_area_register_early(struct vm_struct *vm, size_t align) +{ + static size_t vm_init_off __initdata; + unsigned long addr; + + addr = ALIGN(VMALLOC_START + vm_init_off, align); + vm_init_off = PFN_ALIGN(addr + vm->size) - VMALLOC_START; + + vm->addr = (void *)addr; + + vm_area_add_early(vm); +} + +static void vmap_init_free_space(void) +{ + unsigned long vmap_start = 1; + const unsigned long vmap_end = ULONG_MAX; + struct vmap_area *busy, *free; + + /* + * B F B B B F + * -|-----|.....|-----|-----|-----|.....|- + * | The KVA space | + * |<--------------------------------->| + */ + list_for_each_entry(busy, &vmap_area_list, list) { + if (busy->va_start - vmap_start > 0) { + free = kmem_cache_zalloc(vmap_area_cachep, GFP_NOWAIT); + if (!WARN_ON_ONCE(!free)) { + free->va_start = vmap_start; + free->va_end = busy->va_start; + + insert_vmap_area_augment(free, NULL, + &free_vmap_area_root, + &free_vmap_area_list); + } + } + + vmap_start = busy->va_end; + } + + if (vmap_end - vmap_start > 0) { + free = kmem_cache_zalloc(vmap_area_cachep, GFP_NOWAIT); + if (!WARN_ON_ONCE(!free)) { + free->va_start = vmap_start; + free->va_end = vmap_end; + + insert_vmap_area_augment(free, NULL, + &free_vmap_area_root, + &free_vmap_area_list); + } + } +} + +void __init vmalloc_init(void) +{ + struct vmap_area *va; + struct vm_struct *tmp; + int i; + + /* + * Create the cache for vmap_area objects. + */ + vmap_area_cachep = KMEM_CACHE(vmap_area, SLAB_PANIC); + + for_each_possible_cpu(i) { + struct vmap_block_queue *vbq; + struct vfree_deferred *p; + + vbq = &per_cpu(vmap_block_queue, i); + spin_lock_init(&vbq->lock); + INIT_LIST_HEAD(&vbq->free); + p = &per_cpu(vfree_deferred, i); + init_llist_head(&p->list); + INIT_WORK(&p->wq, free_work); + } + + /* Import existing vmlist entries. */ + for (tmp = vmlist; tmp; tmp = tmp->next) { + va = kmem_cache_zalloc(vmap_area_cachep, GFP_NOWAIT); + if (WARN_ON_ONCE(!va)) + continue; + + va->va_start = (unsigned long)tmp->addr; + va->va_end = va->va_start + tmp->size; + va->vm = tmp; + insert_vmap_area(va, &vmap_area_root, &vmap_area_list); + } + + /* + * Now we can initialize a free vmap space. + */ + vmap_init_free_space(); + vmap_initialized = true; +} + +/** + * unmap_kernel_range - unmap kernel VM area and flush cache and TLB + * @addr: start of the VM area to unmap + * @size: size of the VM area to unmap + * + * Similar to unmap_kernel_range_noflush() but flushes vcache before + * the unmapping and tlb after. + */ +void unmap_kernel_range(unsigned long addr, unsigned long size) +{ + unsigned long end = addr + size; + + flush_cache_vunmap(addr, end); + unmap_kernel_range_noflush(addr, size); + flush_tlb_kernel_range(addr, end); +} + +static inline void setup_vmalloc_vm_locked(struct vm_struct *vm, + struct vmap_area *va, unsigned long flags, const void *caller) +{ + vm->flags = flags; + vm->addr = (void *)va->va_start; + vm->size = va->va_end - va->va_start; + vm->caller = caller; + va->vm = vm; +} + +static void setup_vmalloc_vm(struct vm_struct *vm, struct vmap_area *va, + unsigned long flags, const void *caller) +{ + spin_lock(&vmap_area_lock); + setup_vmalloc_vm_locked(vm, va, flags, caller); + spin_unlock(&vmap_area_lock); +} + +static void clear_vm_uninitialized_flag(struct vm_struct *vm) +{ + /* + * Before removing VM_UNINITIALIZED, + * we should make sure that vm has proper values. + * Pair with smp_rmb() in show_numa_info(). + */ + smp_wmb(); + vm->flags &= ~VM_UNINITIALIZED; +} + +static struct vm_struct *__get_vm_area_node(unsigned long size, + unsigned long align, unsigned long flags, unsigned long start, + unsigned long end, int node, gfp_t gfp_mask, const void *caller) +{ + struct vmap_area *va; + struct vm_struct *area; + unsigned long requested_size = size; + + BUG_ON(in_interrupt()); + size = PAGE_ALIGN(size); + if (unlikely(!size)) + return NULL; + + if (flags & VM_IOREMAP) + align = 1ul << clamp_t(int, get_count_order_long(size), + PAGE_SHIFT, IOREMAP_MAX_ORDER); + + area = kzalloc_node(sizeof(*area), gfp_mask & GFP_RECLAIM_MASK, node); + if (unlikely(!area)) + return NULL; + + if (!(flags & VM_NO_GUARD)) + size += PAGE_SIZE; + + va = alloc_vmap_area(size, align, start, end, node, gfp_mask); + if (IS_ERR(va)) { + kfree(area); + return NULL; + } + + kasan_unpoison_vmalloc((void *)va->va_start, requested_size); + + setup_vmalloc_vm(area, va, flags, caller); + + return area; +} + +struct vm_struct *__get_vm_area_caller(unsigned long size, unsigned long flags, + unsigned long start, unsigned long end, + const void *caller) +{ + return __get_vm_area_node(size, 1, flags, start, end, NUMA_NO_NODE, + GFP_KERNEL, caller); +} + +/** + * get_vm_area - reserve a contiguous kernel virtual area + * @size: size of the area + * @flags: %VM_IOREMAP for I/O mappings or VM_ALLOC + * + * Search an area of @size in the kernel virtual mapping area, + * and reserved it for out purposes. Returns the area descriptor + * on success or %NULL on failure. + * + * Return: the area descriptor on success or %NULL on failure. + */ +struct vm_struct *get_vm_area(unsigned long size, unsigned long flags) +{ + return __get_vm_area_node(size, 1, flags, VMALLOC_START, VMALLOC_END, + NUMA_NO_NODE, GFP_KERNEL, + __builtin_return_address(0)); +} + +struct vm_struct *get_vm_area_caller(unsigned long size, unsigned long flags, + const void *caller) +{ + return __get_vm_area_node(size, 1, flags, VMALLOC_START, VMALLOC_END, + NUMA_NO_NODE, GFP_KERNEL, caller); +} + +/** + * find_vm_area - find a continuous kernel virtual area + * @addr: base address + * + * Search for the kernel VM area starting at @addr, and return it. + * It is up to the caller to do all required locking to keep the returned + * pointer valid. + * + * Return: the area descriptor on success or %NULL on failure. + */ +struct vm_struct *find_vm_area(const void *addr) +{ + struct vmap_area *va; + + va = find_vmap_area((unsigned long)addr); + if (!va) + return NULL; + + return va->vm; +} + +/** + * remove_vm_area - find and remove a continuous kernel virtual area + * @addr: base address + * + * Search for the kernel VM area starting at @addr, and remove it. + * This function returns the found VM area, but using it is NOT safe + * on SMP machines, except for its size or flags. + * + * Return: the area descriptor on success or %NULL on failure. + */ +struct vm_struct *remove_vm_area(const void *addr) +{ + struct vmap_area *va; + + might_sleep(); + + spin_lock(&vmap_area_lock); + va = __find_vmap_area((unsigned long)addr); + if (va && va->vm) { + struct vm_struct *vm = va->vm; + + va->vm = NULL; + spin_unlock(&vmap_area_lock); + + kasan_free_shadow(vm); + free_unmap_vmap_area(va); + + return vm; + } + + spin_unlock(&vmap_area_lock); + return NULL; +} + +static inline void set_area_direct_map(const struct vm_struct *area, + int (*set_direct_map)(struct page *page)) +{ + int i; + + for (i = 0; i < area->nr_pages; i++) + if (page_address(area->pages[i])) + set_direct_map(area->pages[i]); +} + +/* Handle removing and resetting vm mappings related to the vm_struct. */ +static void vm_remove_mappings(struct vm_struct *area, int deallocate_pages) +{ + unsigned long start = ULONG_MAX, end = 0; + int flush_reset = area->flags & VM_FLUSH_RESET_PERMS; + int flush_dmap = 0; + int i; + + remove_vm_area(area->addr); + + /* If this is not VM_FLUSH_RESET_PERMS memory, no need for the below. */ + if (!flush_reset) + return; + + /* + * If not deallocating pages, just do the flush of the VM area and + * return. + */ + if (!deallocate_pages) { + vm_unmap_aliases(); + return; + } + + /* + * If execution gets here, flush the vm mapping and reset the direct + * map. Find the start and end range of the direct mappings to make sure + * the vm_unmap_aliases() flush includes the direct map. + */ + for (i = 0; i < area->nr_pages; i++) { + unsigned long addr = (unsigned long)page_address(area->pages[i]); + if (addr) { + start = min(addr, start); + end = max(addr + PAGE_SIZE, end); + flush_dmap = 1; + } + } + + /* + * Set direct map to something invalid so that it won't be cached if + * there are any accesses after the TLB flush, then flush the TLB and + * reset the direct map permissions to the default. + */ + set_area_direct_map(area, set_direct_map_invalid_noflush); + _vm_unmap_aliases(start, end, flush_dmap); + set_area_direct_map(area, set_direct_map_default_noflush); +} + +static void __vunmap(const void *addr, int deallocate_pages) +{ + struct vm_struct *area; + + if (!addr) + return; + + if (WARN(!PAGE_ALIGNED(addr), "Trying to vfree() bad address (%p)\n", + addr)) + return; + + area = find_vm_area(addr); + if (unlikely(!area)) { + WARN(1, KERN_ERR "Trying to vfree() nonexistent vm area (%p)\n", + addr); + return; + } + + debug_check_no_locks_freed(area->addr, get_vm_area_size(area)); + debug_check_no_obj_freed(area->addr, get_vm_area_size(area)); + + kasan_poison_vmalloc(area->addr, get_vm_area_size(area)); + + vm_remove_mappings(area, deallocate_pages); + + if (deallocate_pages) { + int i; + + for (i = 0; i < area->nr_pages; i++) { + struct page *page = area->pages[i]; + + BUG_ON(!page); + __free_pages(page, 0); + } + atomic_long_sub(area->nr_pages, &nr_vmalloc_pages); + + kvfree(area->pages); + } + + kfree(area); + return; +} + +static inline void __vfree_deferred(const void *addr) +{ + /* + * Use raw_cpu_ptr() because this can be called from preemptible + * context. Preemption is absolutely fine here, because the llist_add() + * implementation is lockless, so it works even if we are adding to + * another cpu's list. schedule_work() should be fine with this too. + */ + struct vfree_deferred *p = raw_cpu_ptr(&vfree_deferred); + + if (llist_add((struct llist_node *)addr, &p->list)) + schedule_work(&p->wq); +} + +/** + * vfree_atomic - release memory allocated by vmalloc() + * @addr: memory base address + * + * This one is just like vfree() but can be called in any atomic context + * except NMIs. + */ +void vfree_atomic(const void *addr) +{ + BUG_ON(in_nmi()); + + kmemleak_free(addr); + + if (!addr) + return; + __vfree_deferred(addr); +} + +static void __vfree(const void *addr) +{ + if (unlikely(in_interrupt())) + __vfree_deferred(addr); + else + __vunmap(addr, 1); +} + +/** + * vfree - Release memory allocated by vmalloc() + * @addr: Memory base address + * + * Free the virtually continuous memory area starting at @addr, as obtained + * from one of the vmalloc() family of APIs. This will usually also free the + * physical memory underlying the virtual allocation, but that memory is + * reference counted, so it will not be freed until the last user goes away. + * + * If @addr is NULL, no operation is performed. + * + * Context: + * May sleep if called *not* from interrupt context. + * Must not be called in NMI context (strictly speaking, it could be + * if we have CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG, but making the calling + * conventions for vfree() arch-depenedent would be a really bad idea). + */ +void vfree(const void *addr) +{ + BUG_ON(in_nmi()); + + kmemleak_free(addr); + + might_sleep_if(!in_interrupt()); + + if (!addr) + return; + + __vfree(addr); +} +EXPORT_SYMBOL(vfree); + +/** + * vunmap - release virtual mapping obtained by vmap() + * @addr: memory base address + * + * Free the virtually contiguous memory area starting at @addr, + * which was created from the page array passed to vmap(). + * + * Must not be called in interrupt context. + */ +void vunmap(const void *addr) +{ + BUG_ON(in_interrupt()); + might_sleep(); + if (addr) + __vunmap(addr, 0); +} +EXPORT_SYMBOL(vunmap); + +/** + * vmap - map an array of pages into virtually contiguous space + * @pages: array of page pointers + * @count: number of pages to map + * @flags: vm_area->flags + * @prot: page protection for the mapping + * + * Maps @count pages from @pages into contiguous kernel virtual space. + * If @flags contains %VM_MAP_PUT_PAGES the ownership of the pages array itself + * (which must be kmalloc or vmalloc memory) and one reference per pages in it + * are transferred from the caller to vmap(), and will be freed / dropped when + * vfree() is called on the return value. + * + * Return: the address of the area or %NULL on failure + */ +void *vmap(struct page **pages, unsigned int count, + unsigned long flags, pgprot_t prot) +{ + struct vm_struct *area; + unsigned long size; /* In bytes */ + + might_sleep(); + + if (count > totalram_pages()) + return NULL; + + size = (unsigned long)count << PAGE_SHIFT; + area = get_vm_area_caller(size, flags, __builtin_return_address(0)); + if (!area) + return NULL; + + if (map_kernel_range((unsigned long)area->addr, size, pgprot_nx(prot), + pages) < 0) { + vunmap(area->addr); + return NULL; + } + + if (flags & VM_MAP_PUT_PAGES) { + area->pages = pages; + area->nr_pages = count; + } + return area->addr; +} +EXPORT_SYMBOL(vmap); + +#ifdef CONFIG_VMAP_PFN +struct vmap_pfn_data { + unsigned long *pfns; + pgprot_t prot; + unsigned int idx; +}; + +static int vmap_pfn_apply(pte_t *pte, unsigned long addr, void *private) +{ + struct vmap_pfn_data *data = private; + + if (WARN_ON_ONCE(pfn_valid(data->pfns[data->idx]))) + return -EINVAL; + *pte = pte_mkspecial(pfn_pte(data->pfns[data->idx++], data->prot)); + return 0; +} + +/** + * vmap_pfn - map an array of PFNs into virtually contiguous space + * @pfns: array of PFNs + * @count: number of pages to map + * @prot: page protection for the mapping + * + * Maps @count PFNs from @pfns into contiguous kernel virtual space and returns + * the start address of the mapping. + */ +void *vmap_pfn(unsigned long *pfns, unsigned int count, pgprot_t prot) +{ + struct vmap_pfn_data data = { .pfns = pfns, .prot = pgprot_nx(prot) }; + struct vm_struct *area; + + area = get_vm_area_caller(count * PAGE_SIZE, VM_IOREMAP, + __builtin_return_address(0)); + if (!area) + return NULL; + if (apply_to_page_range(&init_mm, (unsigned long)area->addr, + count * PAGE_SIZE, vmap_pfn_apply, &data)) { + free_vm_area(area); + return NULL; + } + + flush_cache_vmap((unsigned long)area->addr, + (unsigned long)area->addr + count * PAGE_SIZE); + + return area->addr; +} +EXPORT_SYMBOL_GPL(vmap_pfn); +#endif /* CONFIG_VMAP_PFN */ + +static void *__vmalloc_area_node(struct vm_struct *area, gfp_t gfp_mask, + pgprot_t prot, int node) +{ + const gfp_t nested_gfp = (gfp_mask & GFP_RECLAIM_MASK) | __GFP_ZERO; + unsigned int nr_pages = get_vm_area_size(area) >> PAGE_SHIFT; + unsigned int array_size = nr_pages * sizeof(struct page *), i; + struct page **pages; + + gfp_mask |= __GFP_NOWARN; + if (!(gfp_mask & (GFP_DMA | GFP_DMA32))) + gfp_mask |= __GFP_HIGHMEM; + + /* Please note that the recursion is strictly bounded. */ + if (array_size > PAGE_SIZE) { + pages = __vmalloc_node(array_size, 1, nested_gfp, node, + area->caller); + } else { + pages = kmalloc_node(array_size, nested_gfp, node); + } + + if (!pages) { + remove_vm_area(area->addr); + kfree(area); + return NULL; + } + + area->pages = pages; + area->nr_pages = nr_pages; + + for (i = 0; i < area->nr_pages; i++) { + struct page *page; + + if (node == NUMA_NO_NODE) + page = alloc_page(gfp_mask); + else + page = alloc_pages_node(node, gfp_mask, 0); + + if (unlikely(!page)) { + /* Successfully allocated i pages, free them in __vfree() */ + area->nr_pages = i; + atomic_long_add(area->nr_pages, &nr_vmalloc_pages); + goto fail; + } + area->pages[i] = page; + if (gfpflags_allow_blocking(gfp_mask)) + cond_resched(); + } + atomic_long_add(area->nr_pages, &nr_vmalloc_pages); + + if (map_kernel_range((unsigned long)area->addr, get_vm_area_size(area), + prot, pages) < 0) + goto fail; + + return area->addr; + +fail: + warn_alloc(gfp_mask, NULL, + "vmalloc: allocation failure, allocated %ld of %ld bytes", + (area->nr_pages*PAGE_SIZE), area->size); + __vfree(area->addr); + return NULL; +} + +/** + * __vmalloc_node_range - allocate virtually contiguous memory + * @size: allocation size + * @align: desired alignment + * @start: vm area range start + * @end: vm area range end + * @gfp_mask: flags for the page level allocator + * @prot: protection mask for the allocated pages + * @vm_flags: additional vm area flags (e.g. %VM_NO_GUARD) + * @node: node to use for allocation or NUMA_NO_NODE + * @caller: caller's return address + * + * Allocate enough pages to cover @size from the page level + * allocator with @gfp_mask flags. Map them into contiguous + * kernel virtual space, using a pagetable protection of @prot. + * + * Return: the address of the area or %NULL on failure + */ +void *__vmalloc_node_range(unsigned long size, unsigned long align, + unsigned long start, unsigned long end, gfp_t gfp_mask, + pgprot_t prot, unsigned long vm_flags, int node, + const void *caller) +{ + struct vm_struct *area; + void *addr; + unsigned long real_size = size; + + size = PAGE_ALIGN(size); + if (!size || (size >> PAGE_SHIFT) > totalram_pages()) + goto fail; + + area = __get_vm_area_node(real_size, align, VM_ALLOC | VM_UNINITIALIZED | + vm_flags, start, end, node, gfp_mask, caller); + if (!area) + goto fail; + + addr = __vmalloc_area_node(area, gfp_mask, prot, node); + if (!addr) + return NULL; + + /* + * In this function, newly allocated vm_struct has VM_UNINITIALIZED + * flag. It means that vm_struct is not fully initialized. + * Now, it is fully initialized, so remove this flag here. + */ + clear_vm_uninitialized_flag(area); + + kmemleak_vmalloc(area, size, gfp_mask); + + return addr; + +fail: + warn_alloc(gfp_mask, NULL, + "vmalloc: allocation failure: %lu bytes", real_size); + return NULL; +} + +/** + * __vmalloc_node - allocate virtually contiguous memory + * @size: allocation size + * @align: desired alignment + * @gfp_mask: flags for the page level allocator + * @node: node to use for allocation or NUMA_NO_NODE + * @caller: caller's return address + * + * Allocate enough pages to cover @size from the page level allocator with + * @gfp_mask flags. Map them into contiguous kernel virtual space. + * + * Reclaim modifiers in @gfp_mask - __GFP_NORETRY, __GFP_RETRY_MAYFAIL + * and __GFP_NOFAIL are not supported + * + * Any use of gfp flags outside of GFP_KERNEL should be consulted + * with mm people. + * + * Return: pointer to the allocated memory or %NULL on error + */ +void *__vmalloc_node(unsigned long size, unsigned long align, + gfp_t gfp_mask, int node, const void *caller) +{ + return __vmalloc_node_range(size, align, VMALLOC_START, VMALLOC_END, + gfp_mask, PAGE_KERNEL, 0, node, caller); +} +/* + * This is only for performance analysis of vmalloc and stress purpose. + * It is required by vmalloc test module, therefore do not use it other + * than that. + */ +#ifdef CONFIG_TEST_VMALLOC_MODULE +EXPORT_SYMBOL_GPL(__vmalloc_node); +#endif + +void *__vmalloc(unsigned long size, gfp_t gfp_mask) +{ + return __vmalloc_node(size, 1, gfp_mask, NUMA_NO_NODE, + __builtin_return_address(0)); +} +EXPORT_SYMBOL(__vmalloc); + +/** + * vmalloc - allocate virtually contiguous memory + * @size: allocation size + * + * Allocate enough pages to cover @size from the page level + * allocator and map them into contiguous kernel virtual space. + * + * For tight control over page level allocator and protection flags + * use __vmalloc() instead. + * + * Return: pointer to the allocated memory or %NULL on error + */ +void *vmalloc(unsigned long size) +{ + return __vmalloc_node(size, 1, GFP_KERNEL, NUMA_NO_NODE, + __builtin_return_address(0)); +} +EXPORT_SYMBOL(vmalloc); + +/** + * vzalloc - allocate virtually contiguous memory with zero fill + * @size: allocation size + * + * Allocate enough pages to cover @size from the page level + * allocator and map them into contiguous kernel virtual space. + * The memory allocated is set to zero. + * + * For tight control over page level allocator and protection flags + * use __vmalloc() instead. + * + * Return: pointer to the allocated memory or %NULL on error + */ +void *vzalloc(unsigned long size) +{ + return __vmalloc_node(size, 1, GFP_KERNEL | __GFP_ZERO, NUMA_NO_NODE, + __builtin_return_address(0)); +} +EXPORT_SYMBOL(vzalloc); + +/** + * vmalloc_user - allocate zeroed virtually contiguous memory for userspace + * @size: allocation size + * + * The resulting memory area is zeroed so it can be mapped to userspace + * without leaking data. + * + * Return: pointer to the allocated memory or %NULL on error + */ +void *vmalloc_user(unsigned long size) +{ + return __vmalloc_node_range(size, SHMLBA, VMALLOC_START, VMALLOC_END, + GFP_KERNEL | __GFP_ZERO, PAGE_KERNEL, + VM_USERMAP, NUMA_NO_NODE, + __builtin_return_address(0)); +} +EXPORT_SYMBOL(vmalloc_user); + +/** + * vmalloc_node - allocate memory on a specific node + * @size: allocation size + * @node: numa node + * + * Allocate enough pages to cover @size from the page level + * allocator and map them into contiguous kernel virtual space. + * + * For tight control over page level allocator and protection flags + * use __vmalloc() instead. + * + * Return: pointer to the allocated memory or %NULL on error + */ +void *vmalloc_node(unsigned long size, int node) +{ + return __vmalloc_node(size, 1, GFP_KERNEL, node, + __builtin_return_address(0)); +} +EXPORT_SYMBOL(vmalloc_node); + +/** + * vzalloc_node - allocate memory on a specific node with zero fill + * @size: allocation size + * @node: numa node + * + * Allocate enough pages to cover @size from the page level + * allocator and map them into contiguous kernel virtual space. + * The memory allocated is set to zero. + * + * Return: pointer to the allocated memory or %NULL on error + */ +void *vzalloc_node(unsigned long size, int node) +{ + return __vmalloc_node(size, 1, GFP_KERNEL | __GFP_ZERO, node, + __builtin_return_address(0)); +} +EXPORT_SYMBOL(vzalloc_node); + +#if defined(CONFIG_64BIT) && defined(CONFIG_ZONE_DMA32) +#define GFP_VMALLOC32 (GFP_DMA32 | GFP_KERNEL) +#elif defined(CONFIG_64BIT) && defined(CONFIG_ZONE_DMA) +#define GFP_VMALLOC32 (GFP_DMA | GFP_KERNEL) +#else +/* + * 64b systems should always have either DMA or DMA32 zones. For others + * GFP_DMA32 should do the right thing and use the normal zone. + */ +#define GFP_VMALLOC32 GFP_DMA32 | GFP_KERNEL +#endif + +/** + * vmalloc_32 - allocate virtually contiguous memory (32bit addressable) + * @size: allocation size + * + * Allocate enough 32bit PA addressable pages to cover @size from the + * page level allocator and map them into contiguous kernel virtual space. + * + * Return: pointer to the allocated memory or %NULL on error + */ +void *vmalloc_32(unsigned long size) +{ + return __vmalloc_node(size, 1, GFP_VMALLOC32, NUMA_NO_NODE, + __builtin_return_address(0)); +} +EXPORT_SYMBOL(vmalloc_32); + +/** + * vmalloc_32_user - allocate zeroed virtually contiguous 32bit memory + * @size: allocation size + * + * The resulting memory area is 32bit addressable and zeroed so it can be + * mapped to userspace without leaking data. + * + * Return: pointer to the allocated memory or %NULL on error + */ +void *vmalloc_32_user(unsigned long size) +{ + return __vmalloc_node_range(size, SHMLBA, VMALLOC_START, VMALLOC_END, + GFP_VMALLOC32 | __GFP_ZERO, PAGE_KERNEL, + VM_USERMAP, NUMA_NO_NODE, + __builtin_return_address(0)); +} +EXPORT_SYMBOL(vmalloc_32_user); + +/* + * small helper routine , copy contents to buf from addr. + * If the page is not present, fill zero. + */ + +static int aligned_vread(char *buf, char *addr, unsigned long count) +{ + struct page *p; + int copied = 0; + + while (count) { + unsigned long offset, length; + + offset = offset_in_page(addr); + length = PAGE_SIZE - offset; + if (length > count) + length = count; + p = vmalloc_to_page(addr); + /* + * To do safe access to this _mapped_ area, we need + * lock. But adding lock here means that we need to add + * overhead of vmalloc()/vfree() calles for this _debug_ + * interface, rarely used. Instead of that, we'll use + * kmap() and get small overhead in this access function. + */ + if (p) { + /* + * we can expect USER0 is not used (see vread/vwrite's + * function description) + */ + void *map = kmap_atomic(p); + memcpy(buf, map + offset, length); + kunmap_atomic(map); + } else + memset(buf, 0, length); + + addr += length; + buf += length; + copied += length; + count -= length; + } + return copied; +} + +static int aligned_vwrite(char *buf, char *addr, unsigned long count) +{ + struct page *p; + int copied = 0; + + while (count) { + unsigned long offset, length; + + offset = offset_in_page(addr); + length = PAGE_SIZE - offset; + if (length > count) + length = count; + p = vmalloc_to_page(addr); + /* + * To do safe access to this _mapped_ area, we need + * lock. But adding lock here means that we need to add + * overhead of vmalloc()/vfree() calles for this _debug_ + * interface, rarely used. Instead of that, we'll use + * kmap() and get small overhead in this access function. + */ + if (p) { + /* + * we can expect USER0 is not used (see vread/vwrite's + * function description) + */ + void *map = kmap_atomic(p); + memcpy(map + offset, buf, length); + kunmap_atomic(map); + } + addr += length; + buf += length; + copied += length; + count -= length; + } + return copied; +} + +/** + * vread() - read vmalloc area in a safe way. + * @buf: buffer for reading data + * @addr: vm address. + * @count: number of bytes to be read. + * + * This function checks that addr is a valid vmalloc'ed area, and + * copy data from that area to a given buffer. If the given memory range + * of [addr...addr+count) includes some valid address, data is copied to + * proper area of @buf. If there are memory holes, they'll be zero-filled. + * IOREMAP area is treated as memory hole and no copy is done. + * + * If [addr...addr+count) doesn't includes any intersects with alive + * vm_struct area, returns 0. @buf should be kernel's buffer. + * + * Note: In usual ops, vread() is never necessary because the caller + * should know vmalloc() area is valid and can use memcpy(). + * This is for routines which have to access vmalloc area without + * any information, as /dev/kmem. + * + * Return: number of bytes for which addr and buf should be increased + * (same number as @count) or %0 if [addr...addr+count) doesn't + * include any intersection with valid vmalloc area + */ +long vread(char *buf, char *addr, unsigned long count) +{ + struct vmap_area *va; + struct vm_struct *vm; + char *vaddr, *buf_start = buf; + unsigned long buflen = count; + unsigned long n; + + /* Don't allow overflow */ + if ((unsigned long) addr + count < count) + count = -(unsigned long) addr; + + spin_lock(&vmap_area_lock); + list_for_each_entry(va, &vmap_area_list, list) { + if (!count) + break; + + if (!va->vm) + continue; + + vm = va->vm; + vaddr = (char *) vm->addr; + if (addr >= vaddr + get_vm_area_size(vm)) + continue; + while (addr < vaddr) { + if (count == 0) + goto finished; + *buf = '\0'; + buf++; + addr++; + count--; + } + n = vaddr + get_vm_area_size(vm) - addr; + if (n > count) + n = count; + if (!(vm->flags & VM_IOREMAP)) + aligned_vread(buf, addr, n); + else /* IOREMAP area is treated as memory hole */ + memset(buf, 0, n); + buf += n; + addr += n; + count -= n; + } +finished: + spin_unlock(&vmap_area_lock); + + if (buf == buf_start) + return 0; + /* zero-fill memory holes */ + if (buf != buf_start + buflen) + memset(buf, 0, buflen - (buf - buf_start)); + + return buflen; +} + +/** + * vwrite() - write vmalloc area in a safe way. + * @buf: buffer for source data + * @addr: vm address. + * @count: number of bytes to be read. + * + * This function checks that addr is a valid vmalloc'ed area, and + * copy data from a buffer to the given addr. If specified range of + * [addr...addr+count) includes some valid address, data is copied from + * proper area of @buf. If there are memory holes, no copy to hole. + * IOREMAP area is treated as memory hole and no copy is done. + * + * If [addr...addr+count) doesn't includes any intersects with alive + * vm_struct area, returns 0. @buf should be kernel's buffer. + * + * Note: In usual ops, vwrite() is never necessary because the caller + * should know vmalloc() area is valid and can use memcpy(). + * This is for routines which have to access vmalloc area without + * any information, as /dev/kmem. + * + * Return: number of bytes for which addr and buf should be + * increased (same number as @count) or %0 if [addr...addr+count) + * doesn't include any intersection with valid vmalloc area + */ +long vwrite(char *buf, char *addr, unsigned long count) +{ + struct vmap_area *va; + struct vm_struct *vm; + char *vaddr; + unsigned long n, buflen; + int copied = 0; + + /* Don't allow overflow */ + if ((unsigned long) addr + count < count) + count = -(unsigned long) addr; + buflen = count; + + spin_lock(&vmap_area_lock); + list_for_each_entry(va, &vmap_area_list, list) { + if (!count) + break; + + if (!va->vm) + continue; + + vm = va->vm; + vaddr = (char *) vm->addr; + if (addr >= vaddr + get_vm_area_size(vm)) + continue; + while (addr < vaddr) { + if (count == 0) + goto finished; + buf++; + addr++; + count--; + } + n = vaddr + get_vm_area_size(vm) - addr; + if (n > count) + n = count; + if (!(vm->flags & VM_IOREMAP)) { + aligned_vwrite(buf, addr, n); + copied++; + } + buf += n; + addr += n; + count -= n; + } +finished: + spin_unlock(&vmap_area_lock); + if (!copied) + return 0; + return buflen; +} + +/** + * remap_vmalloc_range_partial - map vmalloc pages to userspace + * @vma: vma to cover + * @uaddr: target user address to start at + * @kaddr: virtual address of vmalloc kernel memory + * @pgoff: offset from @kaddr to start at + * @size: size of map area + * + * Returns: 0 for success, -Exxx on failure + * + * This function checks that @kaddr is a valid vmalloc'ed area, + * and that it is big enough to cover the range starting at + * @uaddr in @vma. Will return failure if that criteria isn't + * met. + * + * Similar to remap_pfn_range() (see mm/memory.c) + */ +int remap_vmalloc_range_partial(struct vm_area_struct *vma, unsigned long uaddr, + void *kaddr, unsigned long pgoff, + unsigned long size) +{ + struct vm_struct *area; + unsigned long off; + unsigned long end_index; + + if (check_shl_overflow(pgoff, PAGE_SHIFT, &off)) + return -EINVAL; + + size = PAGE_ALIGN(size); + + if (!PAGE_ALIGNED(uaddr) || !PAGE_ALIGNED(kaddr)) + return -EINVAL; + + area = find_vm_area(kaddr); + if (!area) + return -EINVAL; + + if (!(area->flags & (VM_USERMAP | VM_DMA_COHERENT))) + return -EINVAL; + + if (check_add_overflow(size, off, &end_index) || + end_index > get_vm_area_size(area)) + return -EINVAL; + kaddr += off; + + do { + struct page *page = vmalloc_to_page(kaddr); + int ret; + + ret = vm_insert_page(vma, uaddr, page); + if (ret) + return ret; + + uaddr += PAGE_SIZE; + kaddr += PAGE_SIZE; + size -= PAGE_SIZE; + } while (size > 0); + + vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP; + + return 0; +} +EXPORT_SYMBOL(remap_vmalloc_range_partial); + +/** + * remap_vmalloc_range - map vmalloc pages to userspace + * @vma: vma to cover (map full range of vma) + * @addr: vmalloc memory + * @pgoff: number of pages into addr before first page to map + * + * Returns: 0 for success, -Exxx on failure + * + * This function checks that addr is a valid vmalloc'ed area, and + * that it is big enough to cover the vma. Will return failure if + * that criteria isn't met. + * + * Similar to remap_pfn_range() (see mm/memory.c) + */ +int remap_vmalloc_range(struct vm_area_struct *vma, void *addr, + unsigned long pgoff) +{ + return remap_vmalloc_range_partial(vma, vma->vm_start, + addr, pgoff, + vma->vm_end - vma->vm_start); +} +EXPORT_SYMBOL(remap_vmalloc_range); + +void free_vm_area(struct vm_struct *area) +{ + struct vm_struct *ret; + ret = remove_vm_area(area->addr); + BUG_ON(ret != area); + kfree(area); +} +EXPORT_SYMBOL_GPL(free_vm_area); + +#ifdef CONFIG_SMP +static struct vmap_area *node_to_va(struct rb_node *n) +{ + return rb_entry_safe(n, struct vmap_area, rb_node); +} + +/** + * pvm_find_va_enclose_addr - find the vmap_area @addr belongs to + * @addr: target address + * + * Returns: vmap_area if it is found. If there is no such area + * the first highest(reverse order) vmap_area is returned + * i.e. va->va_start < addr && va->va_end < addr or NULL + * if there are no any areas before @addr. + */ +static struct vmap_area * +pvm_find_va_enclose_addr(unsigned long addr) +{ + struct vmap_area *va, *tmp; + struct rb_node *n; + + n = free_vmap_area_root.rb_node; + va = NULL; + + while (n) { + tmp = rb_entry(n, struct vmap_area, rb_node); + if (tmp->va_start <= addr) { + va = tmp; + if (tmp->va_end >= addr) + break; + + n = n->rb_right; + } else { + n = n->rb_left; + } + } + + return va; +} + +/** + * pvm_determine_end_from_reverse - find the highest aligned address + * of free block below VMALLOC_END + * @va: + * in - the VA we start the search(reverse order); + * out - the VA with the highest aligned end address. + * + * Returns: determined end address within vmap_area + */ +static unsigned long +pvm_determine_end_from_reverse(struct vmap_area **va, unsigned long align) +{ + unsigned long vmalloc_end = VMALLOC_END & ~(align - 1); + unsigned long addr; + + if (likely(*va)) { + list_for_each_entry_from_reverse((*va), + &free_vmap_area_list, list) { + addr = min((*va)->va_end & ~(align - 1), vmalloc_end); + if ((*va)->va_start < addr) + return addr; + } + } + + return 0; +} + +/** + * pcpu_get_vm_areas - allocate vmalloc areas for percpu allocator + * @offsets: array containing offset of each area + * @sizes: array containing size of each area + * @nr_vms: the number of areas to allocate + * @align: alignment, all entries in @offsets and @sizes must be aligned to this + * + * Returns: kmalloc'd vm_struct pointer array pointing to allocated + * vm_structs on success, %NULL on failure + * + * Percpu allocator wants to use congruent vm areas so that it can + * maintain the offsets among percpu areas. This function allocates + * congruent vmalloc areas for it with GFP_KERNEL. These areas tend to + * be scattered pretty far, distance between two areas easily going up + * to gigabytes. To avoid interacting with regular vmallocs, these + * areas are allocated from top. + * + * Despite its complicated look, this allocator is rather simple. It + * does everything top-down and scans free blocks from the end looking + * for matching base. While scanning, if any of the areas do not fit the + * base address is pulled down to fit the area. Scanning is repeated till + * all the areas fit and then all necessary data structures are inserted + * and the result is returned. + */ +struct vm_struct **pcpu_get_vm_areas(const unsigned long *offsets, + const size_t *sizes, int nr_vms, + size_t align) +{ + const unsigned long vmalloc_start = ALIGN(VMALLOC_START, align); + const unsigned long vmalloc_end = VMALLOC_END & ~(align - 1); + struct vmap_area **vas, *va; + struct vm_struct **vms; + int area, area2, last_area, term_area; + unsigned long base, start, size, end, last_end, orig_start, orig_end; + bool purged = false; + enum fit_type type; + + /* verify parameters and allocate data structures */ + BUG_ON(offset_in_page(align) || !is_power_of_2(align)); + for (last_area = 0, area = 0; area < nr_vms; area++) { + start = offsets[area]; + end = start + sizes[area]; + + /* is everything aligned properly? */ + BUG_ON(!IS_ALIGNED(offsets[area], align)); + BUG_ON(!IS_ALIGNED(sizes[area], align)); + + /* detect the area with the highest address */ + if (start > offsets[last_area]) + last_area = area; + + for (area2 = area + 1; area2 < nr_vms; area2++) { + unsigned long start2 = offsets[area2]; + unsigned long end2 = start2 + sizes[area2]; + + BUG_ON(start2 < end && start < end2); + } + } + last_end = offsets[last_area] + sizes[last_area]; + + if (vmalloc_end - vmalloc_start < last_end) { + WARN_ON(true); + return NULL; + } + + vms = kcalloc(nr_vms, sizeof(vms[0]), GFP_KERNEL); + vas = kcalloc(nr_vms, sizeof(vas[0]), GFP_KERNEL); + if (!vas || !vms) + goto err_free2; + + for (area = 0; area < nr_vms; area++) { + vas[area] = kmem_cache_zalloc(vmap_area_cachep, GFP_KERNEL); + vms[area] = kzalloc(sizeof(struct vm_struct), GFP_KERNEL); + if (!vas[area] || !vms[area]) + goto err_free; + } +retry: + spin_lock(&free_vmap_area_lock); + + /* start scanning - we scan from the top, begin with the last area */ + area = term_area = last_area; + start = offsets[area]; + end = start + sizes[area]; + + va = pvm_find_va_enclose_addr(vmalloc_end); + base = pvm_determine_end_from_reverse(&va, align) - end; + + while (true) { + /* + * base might have underflowed, add last_end before + * comparing. + */ + if (base + last_end < vmalloc_start + last_end) + goto overflow; + + /* + * Fitting base has not been found. + */ + if (va == NULL) + goto overflow; + + /* + * If required width exceeds current VA block, move + * base downwards and then recheck. + */ + if (base + end > va->va_end) { + base = pvm_determine_end_from_reverse(&va, align) - end; + term_area = area; + continue; + } + + /* + * If this VA does not fit, move base downwards and recheck. + */ + if (base + start < va->va_start) { + va = node_to_va(rb_prev(&va->rb_node)); + base = pvm_determine_end_from_reverse(&va, align) - end; + term_area = area; + continue; + } + + /* + * This area fits, move on to the previous one. If + * the previous one is the terminal one, we're done. + */ + area = (area + nr_vms - 1) % nr_vms; + if (area == term_area) + break; + + start = offsets[area]; + end = start + sizes[area]; + va = pvm_find_va_enclose_addr(base + end); + } + + /* we've found a fitting base, insert all va's */ + for (area = 0; area < nr_vms; area++) { + int ret; + + start = base + offsets[area]; + size = sizes[area]; + + va = pvm_find_va_enclose_addr(start); + if (WARN_ON_ONCE(va == NULL)) + /* It is a BUG(), but trigger recovery instead. */ + goto recovery; + + type = classify_va_fit_type(va, start, size); + if (WARN_ON_ONCE(type == NOTHING_FIT)) + /* It is a BUG(), but trigger recovery instead. */ + goto recovery; + + ret = adjust_va_to_fit_type(va, start, size, type); + if (unlikely(ret)) + goto recovery; + + /* Allocated area. */ + va = vas[area]; + va->va_start = start; + va->va_end = start + size; + } + + spin_unlock(&free_vmap_area_lock); + + /* populate the kasan shadow space */ + for (area = 0; area < nr_vms; area++) { + if (kasan_populate_vmalloc(vas[area]->va_start, sizes[area])) + goto err_free_shadow; + + kasan_unpoison_vmalloc((void *)vas[area]->va_start, + sizes[area]); + } + + /* insert all vm's */ + spin_lock(&vmap_area_lock); + for (area = 0; area < nr_vms; area++) { + insert_vmap_area(vas[area], &vmap_area_root, &vmap_area_list); + + setup_vmalloc_vm_locked(vms[area], vas[area], VM_ALLOC, + pcpu_get_vm_areas); + } + spin_unlock(&vmap_area_lock); + + kfree(vas); + return vms; + +recovery: + /* + * Remove previously allocated areas. There is no + * need in removing these areas from the busy tree, + * because they are inserted only on the final step + * and when pcpu_get_vm_areas() is success. + */ + while (area--) { + orig_start = vas[area]->va_start; + orig_end = vas[area]->va_end; + va = merge_or_add_vmap_area(vas[area], &free_vmap_area_root, + &free_vmap_area_list); + if (va) + kasan_release_vmalloc(orig_start, orig_end, + va->va_start, va->va_end); + vas[area] = NULL; + } + +overflow: + spin_unlock(&free_vmap_area_lock); + if (!purged) { + purge_vmap_area_lazy(); + purged = true; + + /* Before "retry", check if we recover. */ + for (area = 0; area < nr_vms; area++) { + if (vas[area]) + continue; + + vas[area] = kmem_cache_zalloc( + vmap_area_cachep, GFP_KERNEL); + if (!vas[area]) + goto err_free; + } + + goto retry; + } + +err_free: + for (area = 0; area < nr_vms; area++) { + if (vas[area]) + kmem_cache_free(vmap_area_cachep, vas[area]); + + kfree(vms[area]); + } +err_free2: + kfree(vas); + kfree(vms); + return NULL; + +err_free_shadow: + spin_lock(&free_vmap_area_lock); + /* + * We release all the vmalloc shadows, even the ones for regions that + * hadn't been successfully added. This relies on kasan_release_vmalloc + * being able to tolerate this case. + */ + for (area = 0; area < nr_vms; area++) { + orig_start = vas[area]->va_start; + orig_end = vas[area]->va_end; + va = merge_or_add_vmap_area(vas[area], &free_vmap_area_root, + &free_vmap_area_list); + if (va) + kasan_release_vmalloc(orig_start, orig_end, + va->va_start, va->va_end); + vas[area] = NULL; + kfree(vms[area]); + } + spin_unlock(&free_vmap_area_lock); + kfree(vas); + kfree(vms); + return NULL; +} + +/** + * pcpu_free_vm_areas - free vmalloc areas for percpu allocator + * @vms: vm_struct pointer array returned by pcpu_get_vm_areas() + * @nr_vms: the number of allocated areas + * + * Free vm_structs and the array allocated by pcpu_get_vm_areas(). + */ +void pcpu_free_vm_areas(struct vm_struct **vms, int nr_vms) +{ + int i; + + for (i = 0; i < nr_vms; i++) + free_vm_area(vms[i]); + kfree(vms); +} +#endif /* CONFIG_SMP */ + +#ifdef CONFIG_PROC_FS +static void *s_start(struct seq_file *m, loff_t *pos) + __acquires(&vmap_purge_lock) + __acquires(&vmap_area_lock) +{ + mutex_lock(&vmap_purge_lock); + spin_lock(&vmap_area_lock); + + return seq_list_start(&vmap_area_list, *pos); +} + +static void *s_next(struct seq_file *m, void *p, loff_t *pos) +{ + return seq_list_next(p, &vmap_area_list, pos); +} + +static void s_stop(struct seq_file *m, void *p) + __releases(&vmap_area_lock) + __releases(&vmap_purge_lock) +{ + spin_unlock(&vmap_area_lock); + mutex_unlock(&vmap_purge_lock); +} + +static void show_numa_info(struct seq_file *m, struct vm_struct *v) +{ + if (IS_ENABLED(CONFIG_NUMA)) { + unsigned int nr, *counters = m->private; + + if (!counters) + return; + + if (v->flags & VM_UNINITIALIZED) + return; + /* Pair with smp_wmb() in clear_vm_uninitialized_flag() */ + smp_rmb(); + + memset(counters, 0, nr_node_ids * sizeof(unsigned int)); + + for (nr = 0; nr < v->nr_pages; nr++) + counters[page_to_nid(v->pages[nr])]++; + + for_each_node_state(nr, N_HIGH_MEMORY) + if (counters[nr]) + seq_printf(m, " N%u=%u", nr, counters[nr]); + } +} + +static void show_purge_info(struct seq_file *m) +{ + struct llist_node *head; + struct vmap_area *va; + + head = READ_ONCE(vmap_purge_list.first); + if (head == NULL) + return; + + llist_for_each_entry(va, head, purge_list) { + seq_printf(m, "0x%pK-0x%pK %7ld unpurged vm_area\n", + (void *)va->va_start, (void *)va->va_end, + va->va_end - va->va_start); + } +} + +static int s_show(struct seq_file *m, void *p) +{ + struct vmap_area *va; + struct vm_struct *v; + + va = list_entry(p, struct vmap_area, list); + + /* + * s_show can encounter race with remove_vm_area, !vm on behalf + * of vmap area is being tear down or vm_map_ram allocation. + */ + if (!va->vm) { + seq_printf(m, "0x%pK-0x%pK %7ld vm_map_ram\n", + (void *)va->va_start, (void *)va->va_end, + va->va_end - va->va_start); + + return 0; + } + + v = va->vm; + + seq_printf(m, "0x%pK-0x%pK %7ld", + v->addr, v->addr + v->size, v->size); + + if (v->caller) + seq_printf(m, " %pS", v->caller); + + if (v->nr_pages) + seq_printf(m, " pages=%d", v->nr_pages); + + if (v->phys_addr) + seq_printf(m, " phys=%pa", &v->phys_addr); + + if (v->flags & VM_IOREMAP) + seq_puts(m, " ioremap"); + + if (v->flags & VM_ALLOC) + seq_puts(m, " vmalloc"); + + if (v->flags & VM_MAP) + seq_puts(m, " vmap"); + + if (v->flags & VM_USERMAP) + seq_puts(m, " user"); + + if (v->flags & VM_DMA_COHERENT) + seq_puts(m, " dma-coherent"); + + if (is_vmalloc_addr(v->pages)) + seq_puts(m, " vpages"); + + show_numa_info(m, v); + seq_putc(m, '\n'); + + /* + * As a final step, dump "unpurged" areas. Note, + * that entire "/proc/vmallocinfo" output will not + * be address sorted, because the purge list is not + * sorted. + */ + if (list_is_last(&va->list, &vmap_area_list)) + show_purge_info(m); + + return 0; +} + +static const struct seq_operations vmalloc_op = { + .start = s_start, + .next = s_next, + .stop = s_stop, + .show = s_show, +}; + +static int __init proc_vmalloc_init(void) +{ + if (IS_ENABLED(CONFIG_NUMA)) + proc_create_seq_private("vmallocinfo", 0400, NULL, + &vmalloc_op, + nr_node_ids * sizeof(unsigned int), NULL); + else + proc_create_seq("vmallocinfo", 0400, NULL, &vmalloc_op); + return 0; +} +module_init(proc_vmalloc_init); + +#endif |