| // SPDX-License-Identifier: GPL-2.0-only |
| /* |
| * linux/mm/vmalloc.c |
| * |
| * 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 |
| */ |
| |
| #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/radix-tree.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" |
| |
| 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); |
| } 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); |
| start = addr; |
| 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. |
| */ |
| 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 |
| BUG(); |
| } 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(struct rb_node *n) |
| { |
| struct vmap_area *va; |
| struct rb_node *node; |
| unsigned long size; |
| bool found = false; |
| |
| if (n == NULL) |
| return; |
| |
| va = rb_entry(n, struct vmap_area, rb_node); |
| size = va->subtree_max_size; |
| node = n; |
| |
| while (node) { |
| va = rb_entry(node, struct vmap_area, rb_node); |
| |
| if (get_subtree_max_size(node->rb_left) == size) { |
| node = node->rb_left; |
| } else { |
| if (va_size(va) == size) { |
| found = true; |
| break; |
| } |
| |
| node = node->rb_right; |
| } |
| } |
| |
| if (!found) { |
| va = rb_entry(n, struct vmap_area, rb_node); |
| pr_emerg("tree is corrupted: %lu, %lu\n", |
| va_size(va), va->subtree_max_size); |
| } |
| |
| augment_tree_propagate_check(n->rb_left); |
| augment_tree_propagate_check(n->rb_right); |
| } |
| #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) |
| { |
| struct rb_node *node = &va->rb_node; |
| unsigned long new_va_sub_max_size; |
| |
| while (node) { |
| va = rb_entry(node, struct vmap_area, rb_node); |
| new_va_sub_max_size = compute_subtree_max_size(va); |
| |
| /* |
| * If the newly calculated maximum available size of the |
| * subtree is equal to the current one, then it means that |
| * the tree is propagated correctly. So we have to stop at |
| * this point to save cycles. |
| */ |
| if (va->subtree_max_size == new_va_sub_max_size) |
| break; |
| |
| va->subtree_max_size = new_va_sub_max_size; |
| node = rb_parent(&va->rb_node); |
| } |
| |
| #if DEBUG_AUGMENT_PROPAGATE_CHECK |
| augment_tree_propagate_check(free_vmap_area_root.rb_node); |
| #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); |
| 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); |
| |
| 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. |
| */ |
| 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); |
| |
| /* |
| * 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; |
| |
| /* Check and update the tree if needed. */ |
| augment_tree_propagate_from(sibling); |
| |
| /* 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) { |
| sibling->va_end = va->va_end; |
| |
| /* Check and update the tree if needed. */ |
| augment_tree_propagate_from(sibling); |
| |
| if (merged) |
| unlink_va(va, root); |
| |
| /* 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); |
| 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 (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); |
| |
| /* |
| * Radix tree 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_SPINLOCK(vmap_block_tree_lock); |
| static RADIX_TREE(vmap_block_tree, GFP_ATOMIC); |
| |
| /* |
| * 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); |
| } |
| |
| err = radix_tree_preload(gfp_mask); |
| if (unlikely(err)) { |
| kfree(vb); |
| free_vmap_area(va); |
| return ERR_PTR(err); |
| } |
| |
| 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); |
| spin_lock(&vmap_block_tree_lock); |
| err = radix_tree_insert(&vmap_block_tree, vb_idx, vb); |
| spin_unlock(&vmap_block_tree_lock); |
| BUG_ON(err); |
| radix_tree_preload_end(); |
| |
| 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; |
| unsigned long vb_idx; |
| |
| vb_idx = addr_to_vb_idx(vb->va->va_start); |
| spin_lock(&vmap_block_tree_lock); |
| tmp = radix_tree_delete(&vmap_block_tree, vb_idx); |
| spin_unlock(&vmap_block_tree_lock); |
| 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 long vb_idx; |
| 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_idx = addr_to_vb_idx(addr); |
| rcu_read_lock(); |
| vb = radix_tree_lookup(&vmap_block_tree, vb_idx); |
| rcu_read_unlock(); |
| BUG_ON(!vb); |
| |
| 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 |
| * @prot: memory protection to use. PAGE_KERNEL for regular RAM |
| * |
| * 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: pointer to the found area or %NULL on faulure |
| */ |
| 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: pointer to the found area or %NULL on faulure |
| */ |
| 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, area->size); |
| |
| 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 vmalloc(), vmalloc_32() or __vmalloc(). If @addr is |
| * NULL, no operation is performed. |
| * |
| * Must not be called in NMI context (strictly speaking, only if we don't |
| * have CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG, but making the calling |
| * conventions for vfree() arch-depenedent would be a really bad idea) |
| * |
| * May sleep if called *not* from interrupt context. |
| * |
| * NOTE: assumes that the object at @addr has a size >= sizeof(llist_node) |
| */ |
| 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. |
| * |
| * 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; |
| } |
| |
| return area->addr; |
| } |
| EXPORT_SYMBOL(vmap); |
| |
| static void *__vmalloc_area_node(struct vm_struct *area, gfp_t gfp_mask, |
| pgprot_t prot, int node) |
| { |
| struct page **pages; |
| unsigned int nr_pages, array_size, i; |
| const gfp_t nested_gfp = (gfp_mask & GFP_RECLAIM_MASK) | __GFP_ZERO; |
| const gfp_t alloc_mask = gfp_mask | __GFP_NOWARN; |
| const gfp_t highmem_mask = (gfp_mask & (GFP_DMA | GFP_DMA32)) ? |
| 0 : |
| __GFP_HIGHMEM; |
| |
| nr_pages = get_vm_area_size(area) >> PAGE_SHIFT; |
| array_size = (nr_pages * sizeof(struct page *)); |
| |
| /* Please note that the recursion is strictly bounded. */ |
| if (array_size > PAGE_SIZE) { |
| pages = __vmalloc_node(array_size, 1, nested_gfp|highmem_mask, |
| 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(alloc_mask|highmem_mask); |
| else |
| page = alloc_pages_node(node, alloc_mask|highmem_mask, 0); |
| |
| if (unlikely(!page)) { |
| /* Successfully allocated i pages, free them in __vunmap() */ |
| 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); |
| |
| /** |
| * vmalloc_exec - allocate virtually contiguous, executable memory |
| * @size: allocation size |
| * |
| * Kernel-internal function to allocate enough pages to cover @size |
| * the page level allocator and map them into contiguous and |
| * executable 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_exec(unsigned long size) |
| { |
| return __vmalloc_node_range(size, 1, VMALLOC_START, VMALLOC_END, |
| GFP_KERNEL, PAGE_KERNEL_EXEC, VM_FLUSH_RESET_PERMS, |
| NUMA_NO_NODE, __builtin_return_address(0)); |
| } |
| |
| #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); |
| |
| static int f(pte_t *pte, unsigned long addr, void *data) |
| { |
| pte_t ***p = data; |
| |
| if (p) { |
| *(*p) = pte; |
| (*p)++; |
| } |
| return 0; |
| } |
| |
| /** |
| * alloc_vm_area - allocate a range of kernel address space |
| * @size: size of the area |
| * @ptes: returns the PTEs for the address space |
| * |
| * Returns: NULL on failure, vm_struct on success |
| * |
| * This function reserves a range of kernel address space, and |
| * allocates pagetables to map that range. No actual mappings |
| * are created. |
| * |
| * If @ptes is non-NULL, pointers to the PTEs (in init_mm) |
| * allocated for the VM area are returned. |
| */ |
| struct vm_struct *alloc_vm_area(size_t size, pte_t **ptes) |
| { |
| struct vm_struct *area; |
| |
| area = get_vm_area_caller(size, VM_IOREMAP, |
| __builtin_return_address(0)); |
| if (area == NULL) |
| return NULL; |
| |
| /* |
| * This ensures that page tables are constructed for this region |
| * of kernel virtual address space and mapped into init_mm. |
| */ |
| if (apply_to_page_range(&init_mm, (unsigned long)area->addr, |
| size, f, ptes ? &ptes : NULL)) { |
| free_vm_area(area); |
| return NULL; |
| } |
| |
| return area; |
| } |
| EXPORT_SYMBOL_GPL(alloc_vm_area); |
| |
| 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); |
| |
| <
|