| /* |
| * 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/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/uaccess.h> |
| #include <asm/tlbflush.h> |
| #include <asm/shmparam.h> |
| |
| #include "internal.h" |
| |
| 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 *llnode = llist_del_all(&p->list); |
| while (llnode) { |
| void *p = llnode; |
| llnode = llist_next(llnode); |
| __vunmap(p, 1); |
| } |
| } |
| |
| /*** Page table manipulation functions ***/ |
| |
| static void vunmap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end) |
| { |
| 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); |
| } |
| |
| static void vunmap_pmd_range(pud_t *pud, unsigned long addr, unsigned long end) |
| { |
| pmd_t *pmd; |
| unsigned long next; |
| |
| pmd = pmd_offset(pud, addr); |
| do { |
| next = pmd_addr_end(addr, end); |
| if (pmd_clear_huge(pmd)) |
| continue; |
| if (pmd_none_or_clear_bad(pmd)) |
| continue; |
| vunmap_pte_range(pmd, addr, next); |
| } while (pmd++, addr = next, addr != end); |
| } |
| |
| static void vunmap_pud_range(p4d_t *p4d, unsigned long addr, unsigned long end) |
| { |
| pud_t *pud; |
| unsigned long next; |
| |
| pud = pud_offset(p4d, addr); |
| do { |
| next = pud_addr_end(addr, end); |
| if (pud_clear_huge(pud)) |
| continue; |
| if (pud_none_or_clear_bad(pud)) |
| continue; |
| vunmap_pmd_range(pud, addr, next); |
| } while (pud++, addr = next, addr != end); |
| } |
| |
| static void vunmap_p4d_range(pgd_t *pgd, unsigned long addr, unsigned long end) |
| { |
| p4d_t *p4d; |
| unsigned long next; |
| |
| p4d = p4d_offset(pgd, addr); |
| do { |
| next = p4d_addr_end(addr, end); |
| if (p4d_clear_huge(p4d)) |
| continue; |
| if (p4d_none_or_clear_bad(p4d)) |
| continue; |
| vunmap_pud_range(p4d, addr, next); |
| } while (p4d++, addr = next, addr != end); |
| } |
| |
| static void vunmap_page_range(unsigned long addr, unsigned long end) |
| { |
| pgd_t *pgd; |
| unsigned long next; |
| |
| BUG_ON(addr >= end); |
| pgd = pgd_offset_k(addr); |
| do { |
| next = pgd_addr_end(addr, end); |
| if (pgd_none_or_clear_bad(pgd)) |
| continue; |
| vunmap_p4d_range(pgd, addr, next); |
| } while (pgd++, addr = next, addr != end); |
| } |
| |
| static int vmap_pte_range(pmd_t *pmd, unsigned long addr, |
| unsigned long end, pgprot_t prot, struct page **pages, int *nr) |
| { |
| 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(pmd, addr); |
| 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); |
| return 0; |
| } |
| |
| static int vmap_pmd_range(pud_t *pud, unsigned long addr, |
| unsigned long end, pgprot_t prot, struct page **pages, int *nr) |
| { |
| pmd_t *pmd; |
| unsigned long next; |
| |
| pmd = pmd_alloc(&init_mm, pud, addr); |
| if (!pmd) |
| return -ENOMEM; |
| do { |
| next = pmd_addr_end(addr, end); |
| if (vmap_pte_range(pmd, addr, next, prot, pages, nr)) |
| 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) |
| { |
| pud_t *pud; |
| unsigned long next; |
| |
| pud = pud_alloc(&init_mm, p4d, addr); |
| if (!pud) |
| return -ENOMEM; |
| do { |
| next = pud_addr_end(addr, end); |
| if (vmap_pmd_range(pud, addr, next, prot, pages, nr)) |
| 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) |
| { |
| p4d_t *p4d; |
| unsigned long next; |
| |
| p4d = p4d_alloc(&init_mm, pgd, addr); |
| if (!p4d) |
| return -ENOMEM; |
| do { |
| next = p4d_addr_end(addr, end); |
| if (vmap_pud_range(p4d, addr, next, prot, pages, nr)) |
| return -ENOMEM; |
| } while (p4d++, addr = next, addr != end); |
| return 0; |
| } |
| |
| /* |
| * Set up page tables in kva (addr, end). The ptes shall have prot "prot", and |
| * will have pfns corresponding to the "pages" array. |
| * |
| * Ie. pte at addr+N*PAGE_SIZE shall point to pfn corresponding to pages[N] |
| */ |
| static int vmap_page_range_noflush(unsigned long start, unsigned long end, |
| pgprot_t prot, struct page **pages) |
| { |
| pgd_t *pgd; |
| unsigned long next; |
| unsigned long addr = start; |
| int err = 0; |
| int nr = 0; |
| |
| BUG_ON(addr >= end); |
| pgd = pgd_offset_k(addr); |
| do { |
| next = pgd_addr_end(addr, end); |
| err = vmap_p4d_range(pgd, addr, next, prot, pages, &nr); |
| if (err) |
| return err; |
| } while (pgd++, addr = next, addr != end); |
| |
| return nr; |
| } |
| |
| static int vmap_page_range(unsigned long start, unsigned long end, |
| pgprot_t prot, struct page **pages) |
| { |
| int ret; |
| |
| ret = vmap_page_range_noflush(start, end, prot, pages); |
| flush_cache_vmap(start, end); |
| 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); |
| if (pud_none(*pud)) |
| return NULL; |
| pmd = pmd_offset(pud, addr); |
| if (pmd_none(*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 VM_VM_AREA 0x04 |
| |
| static DEFINE_SPINLOCK(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; |
| |
| /* The vmap cache globals are protected by vmap_area_lock */ |
| static struct rb_node *free_vmap_cache; |
| static unsigned long cached_hole_size; |
| static unsigned long cached_vstart; |
| static unsigned long cached_align; |
| |
| static unsigned long vmap_area_pcpu_hole; |
| |
| 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; |
| } |
| |
| static void __insert_vmap_area(struct vmap_area *va) |
| { |
| struct rb_node **p = &vmap_area_root.rb_node; |
| struct rb_node *parent = NULL; |
| struct rb_node *tmp; |
| |
| while (*p) { |
| struct vmap_area *tmp_va; |
| |
| parent = *p; |
| tmp_va = rb_entry(parent, struct vmap_area, rb_node); |
| if (va->va_start < tmp_va->va_end) |
| p = &(*p)->rb_left; |
| else if (va->va_end > tmp_va->va_start) |
| p = &(*p)->rb_right; |
| else |
| BUG(); |
| } |
| |
| rb_link_node(&va->rb_node, parent, p); |
| rb_insert_color(&va->rb_node, &vmap_area_root); |
| |
| /* address-sort this list */ |
| tmp = rb_prev(&va->rb_node); |
| if (tmp) { |
| struct vmap_area *prev; |
| prev = rb_entry(tmp, struct vmap_area, rb_node); |
| list_add_rcu(&va->list, &prev->list); |
| } else |
| list_add_rcu(&va->list, &vmap_area_list); |
| } |
| |
| static void purge_vmap_area_lazy(void); |
| |
| static BLOCKING_NOTIFIER_HEAD(vmap_notify_list); |
| |
| /* |
| * 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; |
| struct rb_node *n; |
| unsigned long addr; |
| int purged = 0; |
| struct vmap_area *first; |
| |
| BUG_ON(!size); |
| BUG_ON(offset_in_page(size)); |
| BUG_ON(!is_power_of_2(align)); |
| |
| might_sleep(); |
| |
| va = kmalloc_node(sizeof(struct vmap_area), |
| gfp_mask & GFP_RECLAIM_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 & GFP_RECLAIM_MASK); |
| |
| retry: |
| spin_lock(&vmap_area_lock); |
| /* |
| * Invalidate cache if we have more permissive parameters. |
| * cached_hole_size notes the largest hole noticed _below_ |
| * the vmap_area cached in free_vmap_cache: if size fits |
| * into that hole, we want to scan from vstart to reuse |
| * the hole instead of allocating above free_vmap_cache. |
| * Note that __free_vmap_area may update free_vmap_cache |
| * without updating cached_hole_size or cached_align. |
| */ |
| if (!free_vmap_cache || |
| size < cached_hole_size || |
| vstart < cached_vstart || |
| align < cached_align) { |
| nocache: |
| cached_hole_size = 0; |
| free_vmap_cache = NULL; |
| } |
| /* record if we encounter less permissive parameters */ |
| cached_vstart = vstart; |
| cached_align = align; |
| |
| /* find starting point for our search */ |
| if (free_vmap_cache) { |
| first = rb_entry(free_vmap_cache, struct vmap_area, rb_node); |
| addr = ALIGN(first->va_end, align); |
| if (addr < vstart) |
| goto nocache; |
| if (addr + size < addr) |
| goto overflow; |
| |
| } else { |
| addr = ALIGN(vstart, align); |
| if (addr + size < addr) |
| goto overflow; |
| |
| n = vmap_area_root.rb_node; |
| first = NULL; |
| |
| while (n) { |
| struct vmap_area *tmp; |
| tmp = rb_entry(n, struct vmap_area, rb_node); |
| if (tmp->va_end >= addr) { |
| first = tmp; |
| if (tmp->va_start <= addr) |
| break; |
| n = n->rb_left; |
| } else |
| n = n->rb_right; |
| } |
| |
| if (!first) |
| goto found; |
| } |
| |
| /* from the starting point, walk areas until a suitable hole is found */ |
| while (addr + size > first->va_start && addr + size <= vend) { |
| if (addr + cached_hole_size < first->va_start) |
| cached_hole_size = first->va_start - addr; |
| addr = ALIGN(first->va_end, align); |
| if (addr + size < addr) |
| goto overflow; |
| |
| if (list_is_last(&first->list, &vmap_area_list)) |
| goto found; |
| |
| first = list_next_entry(first, list); |
| } |
| |
| found: |
| if (addr + size > vend) |
| goto overflow; |
| |
| va->va_start = addr; |
| va->va_end = addr + size; |
| va->flags = 0; |
| __insert_vmap_area(va); |
| free_vmap_cache = &va->rb_node; |
| 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); |
| |
| return va; |
| |
| overflow: |
| spin_unlock(&vmap_area_lock); |
| 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 (printk_ratelimit()) |
| pr_warn("vmap allocation for size %lu failed: use vmalloc=<size> to increase size\n", |
| size); |
| kfree(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); |
| |
| static void __free_vmap_area(struct vmap_area *va) |
| { |
| BUG_ON(RB_EMPTY_NODE(&va->rb_node)); |
| |
| if (free_vmap_cache) { |
| if (va->va_end < cached_vstart) { |
| free_vmap_cache = NULL; |
| } else { |
| struct vmap_area *cache; |
| cache = rb_entry(free_vmap_cache, struct vmap_area, rb_node); |
| if (va->va_start <= cache->va_start) { |
| free_vmap_cache = rb_prev(&va->rb_node); |
| /* |
| * We don't try to update cached_hole_size or |
| * cached_align, but it won't go very wrong. |
| */ |
| } |
| } |
| } |
| rb_erase(&va->rb_node, &vmap_area_root); |
| RB_CLEAR_NODE(&va->rb_node); |
| list_del_rcu(&va->list); |
| |
| /* |
| * Track the highest possible candidate for pcpu area |
| * allocation. Areas outside of vmalloc area can be returned |
| * here too, consider only end addresses which fall inside |
| * vmalloc area proper. |
| */ |
| if (va->va_end > VMALLOC_START && va->va_end <= VMALLOC_END) |
| vmap_area_pcpu_hole = max(vmap_area_pcpu_hole, va->va_end); |
| |
| kfree_rcu(va, rcu_head); |
| } |
| |
| /* |
| * Free a region of KVA allocated by alloc_vmap_area |
| */ |
| static void free_vmap_area(struct vmap_area *va) |
| { |
| spin_lock(&vmap_area_lock); |
| __free_vmap_area(va); |
| spin_unlock(&vmap_area_lock); |
| } |
| |
| /* |
| * Clear the pagetable entries of a given vmap_area |
| */ |
| static void unmap_vmap_area(struct vmap_area *va) |
| { |
| vunmap_page_range(va->va_start, va->va_end); |
| } |
| |
| static void vmap_debug_free_range(unsigned long start, unsigned long end) |
| { |
| /* |
| * Unmap page tables and force a TLB flush immediately if pagealloc |
| * debugging is enabled. This catches use after free bugs similarly to |
| * those in linear kernel virtual address space after a page has been |
| * freed. |
| * |
| * All the lazy freeing logic is still retained, in order to minimise |
| * intrusiveness of this debugging feature. |
| * |
| * This is going to be *slow* (linear kernel virtual address debugging |
| * doesn't do a broadcast TLB flush so it is a lot faster). |
| */ |
| if (debug_pagealloc_enabled()) { |
| vunmap_page_range(start, end); |
| flush_tlb_kernel_range(start, end); |
| } |
| } |
| |
| /* |
| * 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_t vmap_lazy_nr = ATOMIC_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_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) |
| { |
| struct llist_node *valist; |
| struct vmap_area *va; |
| struct vmap_area *n_va; |
| bool do_free = false; |
| |
| lockdep_assert_held(&vmap_purge_lock); |
| |
| valist = llist_del_all(&vmap_purge_list); |
| 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; |
| do_free = true; |
| } |
| |
| if (!do_free) |
| return false; |
| |
| flush_tlb_kernel_range(start, end); |
| |
| spin_lock(&vmap_area_lock); |
| llist_for_each_entry_safe(va, n_va, valist, purge_list) { |
| int nr = (va->va_end - va->va_start) >> PAGE_SHIFT; |
| |
| __free_vmap_area(va); |
| atomic_sub(nr, &vmap_lazy_nr); |
| cond_resched_lock(&vmap_area_lock); |
| } |
| spin_unlock(&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) |
| { |
| int nr_lazy; |
| |
| nr_lazy = atomic_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_vmap_area(va); |
| 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) |
| |
| static bool vmap_initialized __read_mostly = false; |
| |
| 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 |
| * |
| * Returns: 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(const void *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((unsigned long)addr, (unsigned long)addr + size); |
| |
| order = get_order(size); |
| |
| offset = (unsigned long)addr & (VMAP_BLOCK_SIZE - 1); |
| offset >>= PAGE_SHIFT; |
| |
| vb_idx = addr_to_vb_idx((unsigned long)addr); |
| rcu_read_lock(); |
| vb = radix_tree_lookup(&vmap_block_tree, vb_idx); |
| rcu_read_unlock(); |
| BUG_ON(!vb); |
| |
| vunmap_page_range((unsigned long)addr, (unsigned long)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); |
| } |
| |
| /** |
| * 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 cpu; |
| int flush = 0; |
| |
| 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); |
| } |
| 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)); |
| |
| debug_check_no_locks_freed(mem, size); |
| vmap_debug_free_range(addr, addr+size); |
| |
| if (likely(count <= VMAP_MAX_ALLOC)) { |
| vb_free(mem, size); |
| return; |
| } |
| |
| va = find_vmap_area(addr); |
| BUG_ON(!va); |
| 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, pgprot_t prot) |
| { |
| 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; |
| } |
| if (vmap_page_range(addr, addr + size, prot, 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); |
| } |
| |
| void __init vmalloc_init(void) |
| { |
| struct vmap_area *va; |
| struct vm_struct *tmp; |
| int i; |
| |
| 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 = kzalloc(sizeof(struct vmap_area), GFP_NOWAIT); |
| va->flags = VM_VM_AREA; |
| va->va_start = (unsigned long)tmp->addr; |
| va->va_end = va->va_start + tmp->size; |
| va->vm = tmp; |
| __insert_vmap_area(va); |
| } |
| |
| vmap_area_pcpu_hole = VMALLOC_END; |
| |
| vmap_initialized = true; |
| } |
| |
| /** |
| * 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: |
| * The number of pages mapped on success, -errno on failure. |
| */ |
| int map_kernel_range_noflush(unsigned long addr, unsigned long size, |
| pgprot_t prot, struct page **pages) |
| { |
| return vmap_page_range_noflush(addr, addr + size, prot, pages); |
| } |
| |
| /** |
| * unmap_kernel_range_noflush - unmap kernel VM area |
| * @addr: 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 addr, unsigned long size) |
| { |
| vunmap_page_range(addr, addr + size); |
| } |
| EXPORT_SYMBOL_GPL(unmap_kernel_range_noflush); |
| |
| /** |
| * 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); |
| vunmap_page_range(addr, end); |
| flush_tlb_kernel_range(addr, end); |
| } |
| EXPORT_SYMBOL_GPL(unmap_kernel_range); |
| |
| int map_vm_area(struct vm_struct *area, pgprot_t prot, struct page **pages) |
| { |
| unsigned long addr = (unsigned long)area->addr; |
| unsigned long end = addr + get_vm_area_size(area); |
| int err; |
| |
| err = vmap_page_range(addr, end, prot, pages); |
| |
| return err > 0 ? 0 : err; |
| } |
| EXPORT_SYMBOL_GPL(map_vm_area); |
| |
| static void setup_vmalloc_vm(struct vm_struct *vm, struct vmap_area *va, |
| unsigned long flags, const void *caller) |
| { |
| spin_lock(&vmap_area_lock); |
| vm->flags = flags; |
| vm->addr = (void *)va->va_start; |
| vm->size = va->va_end - va->va_start; |
| vm->caller = caller; |
| va->vm = vm; |
| va->flags |= VM_VM_AREA; |
| 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; |
| |
| 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; |
| } |
| |
| setup_vmalloc_vm(area, va, flags, caller); |
| |
| return area; |
| } |
| |
| struct vm_struct *__get_vm_area(unsigned long size, unsigned long flags, |
| unsigned long start, unsigned long end) |
| { |
| return __get_vm_area_node(size, 1, flags, start, end, NUMA_NO_NODE, |
| GFP_KERNEL, __builtin_return_address(0)); |
| } |
| EXPORT_SYMBOL_GPL(__get_vm_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. |
| */ |
| 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. |
| */ |
| struct vm_struct *find_vm_area(const void *addr) |
| { |
| struct vmap_area *va; |
| |
| va = find_vmap_area((unsigned long)addr); |
| if (va && va->flags & VM_VM_AREA) |
| return va->vm; |
| |
| return NULL; |
| } |
| |
| /** |
| * 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. |
| */ |
| struct vm_struct *remove_vm_area(const void *addr) |
| { |
| struct vmap_area *va; |
| |
| might_sleep(); |
| |
| va = find_vmap_area((unsigned long)addr); |
| if (va && va->flags & VM_VM_AREA) { |
| struct vm_struct *vm = va->vm; |
| |
| spin_lock(&vmap_area_lock); |
| va->vm = NULL; |
| va->flags &= ~VM_VM_AREA; |
| spin_unlock(&vmap_area_lock); |
| |
| vmap_debug_free_range(va->va_start, va->va_end); |
| kasan_free_shadow(vm); |
| free_unmap_vmap_area(va); |
| |
| return vm; |
| } |
| return NULL; |
| } |
| |
| 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 = remove_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(addr, get_vm_area_size(area)); |
| debug_check_no_obj_freed(addr, get_vm_area_size(area)); |
| |
| 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); |
| } |
| |
| 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 |
| * nother 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); |
| } |
| |
| /** |
| * 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) |
| * |
| * 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); |
| |
| if (!addr) |
| return; |
| if (unlikely(in_interrupt())) |
| __vfree_deferred(addr); |
| else |
| __vunmap(addr, 1); |
| } |
| 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. |
| */ |
| 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_vm_area(area, prot, pages)) { |
| vunmap(area->addr); |
| return NULL; |
| } |
| |
| return area->addr; |
| } |
| EXPORT_SYMBOL(vmap); |
| |
| static void *__vmalloc_node(unsigned long size, unsigned long align, |
| gfp_t gfp_mask, pgprot_t prot, |
| int node, const void *caller); |
| 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; |
| |
| nr_pages = get_vm_area_size(area) >> PAGE_SHIFT; |
| array_size = (nr_pages * sizeof(struct page *)); |
| |
| area->nr_pages = nr_pages; |
| /* Please note that the recursion is strictly bounded. */ |
| if (array_size > PAGE_SIZE) { |
| pages = __vmalloc_node(array_size, 1, nested_gfp|__GFP_HIGHMEM, |
| PAGE_KERNEL, node, area->caller); |
| } else { |
| pages = kmalloc_node(array_size, nested_gfp, node); |
| } |
| area->pages = pages; |
| if (!area->pages) { |
| remove_vm_area(area->addr); |
| kfree(area); |
| return NULL; |
| } |
| |
| for (i = 0; i < area->nr_pages; i++) { |
| struct page *page; |
| |
| if (fatal_signal_pending(current)) { |
| area->nr_pages = i; |
| goto fail_no_warn; |
| } |
| |
| if (node == NUMA_NO_NODE) |
| page = alloc_page(alloc_mask); |
| else |
| page = alloc_pages_node(node, alloc_mask, 0); |
| |
| if (unlikely(!page)) { |
| /* Successfully allocated i pages, free them in __vunmap() */ |
| area->nr_pages = i; |
| goto fail; |
| } |
| area->pages[i] = page; |
| if (gfpflags_allow_blocking(gfp_mask)) |
| cond_resched(); |
| } |
| |
| if (map_vm_area(area, prot, pages)) |
| 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); |
| fail_no_warn: |
| 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. |
| */ |
| 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(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); |
| |
| /* |
| * A ref_count = 2 is needed because vm_struct allocated in |
| * __get_vm_area_node() contains a reference to the virtual address of |
| * the vmalloc'ed block. |
| */ |
| kmemleak_alloc(addr, real_size, 2, 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 |
| * @prot: protection mask for the allocated pages |
| * @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. |
| * |
| * Reclaim modifiers in @gfp_mask - __GFP_NORETRY, __GFP_REPEAT |
| * and __GFP_NOFAIL are not supported |
| * |
| * Any use of gfp flags outside of GFP_KERNEL should be consulted |
| * with mm people. |
| * |
| */ |
| static void *__vmalloc_node(unsigned long size, unsigned long align, |
| gfp_t gfp_mask, pgprot_t prot, |
| int node, const void *caller) |
| { |
| return __vmalloc_node_range(size, align, VMALLOC_START, VMALLOC_END, |
| gfp_mask, prot, 0, node, caller); |
| } |
| |
| void *__vmalloc(unsigned long size, gfp_t gfp_mask, pgprot_t prot) |
| { |
| return __vmalloc_node(size, 1, gfp_mask, prot, NUMA_NO_NODE, |
| __builtin_return_address(0)); |
| } |
| EXPORT_SYMBOL(__vmalloc); |
| |
| void *__vmalloc_node_flags(unsigned long size, |
| int node, gfp_t flags) |
| { |
| return __vmalloc_node(size, 1, flags, PAGE_KERNEL, |
| node, __builtin_return_address(0)); |
| } |
| |
| /** |
| * 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. |
| */ |
| void *vmalloc(unsigned long size) |
| { |
| return __vmalloc_node_flags(size, NUMA_NO_NODE, |
| GFP_KERNEL | __GFP_HIGHMEM); |
| } |
| 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. |
| */ |
| void *vzalloc(unsigned long size) |
| { |
| return __vmalloc_node_flags(size, NUMA_NO_NODE, |
| GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO); |
| } |
| 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. |
| */ |
| void *vmalloc_user(unsigned long size) |
| { |
| struct vm_struct *area; |
| void *ret; |
| |
| ret = __vmalloc_node(size, SHMLBA, |
| GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO, |
| PAGE_KERNEL, NUMA_NO_NODE, |
| __builtin_return_address(0)); |
| if (ret) { |
| area = find_vm_area(ret); |
| area->flags |= VM_USERMAP; |
| } |
| return ret; |
| } |
| 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. |
| */ |
| void *vmalloc_node(unsigned long size, int node) |
| { |
| return __vmalloc_node(size, 1, GFP_KERNEL | __GFP_HIGHMEM, PAGE_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. |
| * |
| * For tight control over page level allocator and protection flags |
| * use __vmalloc_node() instead. |
| */ |
| void *vzalloc_node(unsigned long size, int node) |
| { |
| return __vmalloc_node_flags(size, node, |
| GFP_KERNEL | __GFP_HIGHMEM | __GFP_ZERO); |
| } |
| EXPORT_SYMBOL(vzalloc_node); |
| |
| #ifndef PAGE_KERNEL_EXEC |
| # define PAGE_KERNEL_EXEC PAGE_KERNEL |
| #endif |
| |
| /** |
| * 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. |
| */ |
| |
| void *vmalloc_exec(unsigned long size) |
| { |
| return __vmalloc_node(size, 1, GFP_KERNEL | __GFP_HIGHMEM, PAGE_KERNEL_EXEC, |
| 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 |
| #define GFP_VMALLOC32 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. |
| */ |
| void *vmalloc_32(unsigned long size) |
| { |
| return __vmalloc_node(size, 1, GFP_VMALLOC32, PAGE_KERNEL, |
| 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. |
| */ |
| void *vmalloc_32_user(unsigned long size) |
| { |
| struct vm_struct *area; |
| void *ret; |
| |
| ret = __vmalloc_node(size, 1, GFP_VMALLOC32 | __GFP_ZERO, PAGE_KERNEL, |
| NUMA_NO_NODE, __builtin_return_address(0)); |
| if (ret) { |
| area = find_vm_area(ret); |
| area->flags |= VM_USERMAP; |
| } |
| return ret; |
| } |
| 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. |
| * |
| * Returns # of bytes which addr and buf should be increased. |
| * (same number to @count). Returns 0 if [addr...addr+count) doesn't |
| * includes any intersect with alive vmalloc area. |
| * |
| * 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 informaion, as /dev/kmem. |
| * |
| */ |
| |
| 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->flags & VM_VM_AREA)) |
| 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. |
| * |
| * Returns # of bytes which addr and buf should be incresed. |
| * (same number to @count). |
| * If [addr...addr+count) doesn't includes any intersect with valid |
| * vmalloc area, returns 0. |
| * |
| * 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 informaion, as /dev/kmem. |
| */ |
| |
| 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->flags & VM_VM_AREA)) |
| 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 |
| * @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 size) |
| { |
| struct vm_struct *area; |
| |
| 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)) |
| return -EINVAL; |
| |
| if (kaddr + size > area->addr + area->size) |
| return -EINVAL; |
| |
| 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 << PAGE_SHIFT), |
| vma->vm_end - vma->vm_start); |
| } |
| EXPORT_SYMBOL(remap_vmalloc_range); |
| |
| /* |
| * Implement a stub for vmalloc_sync_all() if the architecture chose not to |
| * have one. |
| */ |
| void __weak vmalloc_sync_all(void) |
| { |
| } |
| |
| |
| static int f(pte_t *pte, pgtable_t table, 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_next_prev - find the next and prev vmap_area surrounding @end |
| * @end: target address |
| * @pnext: out arg for the next vmap_area |
| * @pprev: out arg for the previous vmap_area |
| * |
| * Returns: %true if either or both of next and prev are found, |
| * %false if no vmap_area exists |
| * |
| * Find vmap_areas end addresses of which enclose @end. ie. if not |
| * NULL, *pnext->va_end > @end and *pprev->va_end <= @end. |
| */ |
| static bool pvm_find_next_prev(unsigned long end, |
| struct vmap_area **pnext, |
| struct vmap_area **pprev) |
| { |
| struct rb_node *n = vmap_area_root.rb_node; |
| struct vmap_area *va = NULL; |
| |
| while (n) { |
| va = rb_entry(n, struct vmap_area, rb_node); |
| if (end < va->va_end) |
| n = n->rb_left; |
| else if (end > va->va_end) |
| n = n->rb_right; |
| else |
| break; |
| } |
| |
| if (!va) |
| return false; |
| |
| if (va->va_end > end) { |
| *pnext = va; |
| *pprev = node_to_va(rb_prev(&(*pnext)->rb_node)); |
| } else { |
| *pprev = va; |
| *pnext = node_to_va(rb_next(&(*pprev)->rb_node)); |
| } |
| return true; |
| } |
| |
| /** |
| * pvm_determine_end - find the highest aligned address between two vmap_areas |
| * @pnext: in/out arg for the next vmap_area |
| * @pprev: in/out arg for the previous vmap_area |
| * @align: alignment |
| * |
| * Returns: determined end address |
| * |
| * Find the highest aligned address between *@pnext and *@pprev below |
| * VMALLOC_END. *@pnext and *@pprev are adjusted so that the aligned |
| * down address is between the end addresses of the two vmap_areas. |
| * |
| * Please note that the address returned by this function may fall |
| * inside *@pnext vmap_area. The caller is responsible for checking |
| * that. |
| */ |
| static unsigned long pvm_determine_end(struct vmap_area **pnext, |
| struct vmap_area **pprev, |
| unsigned long align) |
| { |
| const unsigned long vmalloc_end = VMALLOC_END & ~(align - 1); |
| unsigned long addr; |
| |
| if (*pnext) |
| addr = min((*pnext)->va_start & ~(align - 1), vmalloc_end); |
| else |
| addr = vmalloc_end; |
| |
| while (*pprev && (*pprev)->va_end > addr) { |
| *pnext = *pprev; |
| *pprev = node_to_va(rb_prev(&(*pnext)->rb_node)); |
| } |
| |
| return addr; |
| } |
| |
| /** |
| * 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 areas from the end looking for |
| * matching slot. While scanning, if any of the areas overlaps with |
| * existing vmap_area, the base address is pulled down to fit the |
| * area. Scanning is repeated till all the areas fit and then all |
| * necessary data structres 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, *prev, *next; |
| struct vm_struct **vms; |
| int area, area2, last_area, term_area; |
| unsigned long base, start, end, last_end; |
| bool purged = false; |
| |
| /* 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 = 0; area2 < nr_vms; area2++) { |
| unsigned long start2 = offsets[area2]; |
| unsigned long end2 = start2 + sizes[area2]; |
| |
| if (area2 == area) |
| continue; |
| |
| BUG_ON(start2 >= start && start2 < end); |
| BUG_ON(end2 <= end && end2 > start); |
| } |
| } |
| 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] = kzalloc(sizeof(struct vmap_area), GFP_KERNEL); |
| vms[area] = kzalloc(sizeof(struct vm_struct), GFP_KERNEL); |
| if (!vas[area] || !vms[area]) |
| goto err_free; |
| } |
| retry: |
| spin_lock(&vmap_area_lock); |
| |
| /* start scanning - we scan from the top, begin with the last area */ |
| area = term_area = last_area; |
| start = offsets[area]; |
| end = start + sizes[area]; |
| |
| if (!pvm_find_next_prev(vmap_area_pcpu_hole, &next, &prev)) { |
| base = vmalloc_end - last_end; |
| goto found; |
| } |
| base = pvm_determine_end(&next, &prev, align) - end; |
| |
| while (true) { |
| BUG_ON(next && next->va_end <= base + end); |
| BUG_ON(prev && prev->va_end > base + end); |
| |
| /* |
| * base might have underflowed, add last_end before |
| * comparing. |
| */ |
| if (base + last_end < vmalloc_start + last_end) { |
| spin_unlock(&vmap_area_lock); |
| if (!purged) { |
| purge_vmap_area_lazy(); |
| purged = true; |
| goto retry; |
| } |
| goto err_free; |
| } |
| |
| /* |
| * If next overlaps, move base downwards so that it's |
| * right below next and then recheck. |
| */ |
| if (next && next->va_start < base + end) { |
| base = pvm_determine_end(&next, &prev, align) - end; |
| term_area = area; |
| continue; |
| } |
| |
| /* |
| * If prev overlaps, shift down next and prev and move |
| * base so that it's right below new next and then |
| * recheck. |
| */ |
| if (prev && prev->va_end > base + start) { |
| next = prev; |
| prev = node_to_va(rb_prev(&next->rb_node)); |
| base = pvm_determine_end(&next, &prev, align) - end; |
| term_area = area; |
| continue; |
| } |
| |
| /* |
| * This area fits, move on to the previous one. If |
| * the previous one is the terminal one, we're done. |
| */ |
| area = (area + nr_vms - 1) % nr_vms; |
| if (area == term_area) |
| break; |
| start = offsets[area]; |
| end = start + sizes[area]; |
| pvm_find_next_prev(base + end, &next, &prev); |
| } |
| found: |
| /* we've found a fitting base, insert all va's */ |
| for (area = 0; area < nr_vms; area++) { |
| struct vmap_area *va = vas[area]; |
| |
| va->va_start = base + offsets[area]; |
| va->va_end = va->va_start + sizes[area]; |
| __insert_vmap_area(va); |
| } |
| |
| vmap_area_pcpu_hole = base + offsets[last_area]; |
| |
| spin_unlock(&vmap_area_lock); |
| |
| /* insert all vm's */ |
| for (area = 0; area < nr_vms; area++) |
| setup_vmalloc_vm(vms[area], vas[area], VM_ALLOC, |
| pcpu_get_vm_areas); |
| |
| kfree(vas); |
| return vms; |
| |
| err_free: |
| for (area = 0; area < nr_vms; area++) { |
| kfree(vas[area]); |
| kfree(vms[area]); |
| } |
| err_free2: |
| kfree(vas); |
| kfree(vms); |
| return NULL; |
| } |
| |
| /** |
| * pcpu_free_vm_areas - free vmalloc areas for percpu allocator |
| * @vms: vm_struct pointer array returned by pcpu_get_vm_areas() |
| * @nr_vms: the number of allocated areas |
| * |
| * Free vm_structs and the array allocated by pcpu_get_vm_areas(). |
| */ |
| void pcpu_free_vm_areas(struct vm_struct **vms, int nr_vms) |
| { |
| int i; |
| |
| for (i = 0; i < nr_vms; i++) |
| free_vm_area(vms[i]); |
| kfree(vms); |
| } |
| #endif /* CONFIG_SMP */ |
| |
| #ifdef CONFIG_PROC_FS |
| static void *s_start(struct seq_file *m, loff_t *pos) |
| __acquires(&vmap_area_lock) |
| { |
| spin_lock(&vmap_area_lock); |
| return seq_list_start(&vmap_area_list, *pos); |
| } |
| |
| static void *s_next(struct seq_file *m, void *p, loff_t *pos) |
| { |
| return seq_list_next(p, &vmap_area_list, pos); |
| } |
| |
| static void s_stop(struct seq_file *m, void *p) |
| __releases(&vmap_area_lock) |
| { |
| spin_unlock(&vmap_area_lock); |
| } |
| |
| static void show_numa_info(struct seq_file *m, struct vm_struct *v) |
| { |
| if (IS_ENABLED(CONFIG_NUMA)) { |
| unsigned int nr, *counters = m->private; |
| |
| if (!counters) |
| return; |
| |
| if (v->flags & VM_UNINITIALIZED) |
| return; |
| /* Pair with smp_wmb() in clear_vm_uninitialized_flag() */ |
| smp_rmb(); |
| |
| memset(counters, 0, nr_node_ids * sizeof(unsigned int)); |
| |
| for (nr = 0; nr < v->nr_pages; nr++) |
| counters[page_to_nid(v->pages[nr])]++; |
| |
| for_each_node_state(nr, N_HIGH_MEMORY) |
| if (counters[nr]) |
| seq_printf(m, " N%u=%u", nr, counters[nr]); |
| } |
| } |
| |
| static int s_show(struct seq_file *m, void *p) |
| { |
| struct vmap_area *va; |
| struct vm_struct *v; |
| |
| va = list_entry(p, struct vmap_area, list); |
| |
| /* |
| * s_show can encounter race with remove_vm_area, !VM_VM_AREA on |
| * behalf of vmap area is being tear down or vm_map_ram allocation. |
| */ |
| if (!(va->flags & VM_VM_AREA)) |
| return 0; |
| |
| v = va->vm; |
| |
| seq_printf(m, "0x%pK-0x%pK %7ld", |
| v->addr, v->addr + v->size, v->size); |
| |
| if (v->caller) |
| seq_printf(m, " %pS", v->caller); |
| |
| if (v->nr_pages) |
| seq_printf(m, " pages=%d", v->nr_pages); |
| |
| if (v->phys_addr) |
| seq_printf(m, " phys=%pa", &v->phys_addr); |
| |
| if (v->flags & VM_IOREMAP) |
| seq_puts(m, " ioremap"); |
| |
| if (v->flags & VM_ALLOC) |
| seq_puts(m, " vmalloc"); |
| |
| if (v->flags & VM_MAP) |
| seq_puts(m, " vmap"); |
| |
| if (v->flags & VM_USERMAP) |
| seq_puts(m, " user"); |
| |
| if (is_vmalloc_addr(v->pages)) |
| seq_puts(m, " vpages"); |
| |
| show_numa_info(m, v); |
| seq_putc(m, '\n'); |
| return 0; |
| } |
| |
| static const struct seq_operations vmalloc_op = { |
| .start = s_start, |
| .next = s_next, |
| .stop = s_stop, |
| .show = s_show, |
| }; |
| |
| static int vmalloc_open(struct inode *inode, struct file *file) |
| { |
| if (IS_ENABLED(CONFIG_NUMA)) |
| return seq_open_private(file, &vmalloc_op, |
| nr_node_ids * sizeof(unsigned int)); |
| else |
| return seq_open(file, &vmalloc_op); |
| } |
| |
| static const struct file_operations proc_vmalloc_operations = { |
| .open = vmalloc_open, |
| .read = seq_read, |
| .llseek = seq_lseek, |
| .release = seq_release_private, |
| }; |
| |
| static int __init proc_vmalloc_init(void) |
| { |
| proc_create("vmallocinfo", S_IRUSR, NULL, &proc_vmalloc_operations); |
| return 0; |
| } |
| module_init(proc_vmalloc_init); |
| |
| #endif |
| |