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Diffstat (limited to '')
| -rw-r--r-- | mm/vmalloc.c | 4495 |
1 files changed, 4495 insertions, 0 deletions
diff --git a/mm/vmalloc.c b/mm/vmalloc.c new file mode 100644 index 0000000000..a3fedb3ee0 --- /dev/null +++ b/mm/vmalloc.c @@ -0,0 +1,4495 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 1993 Linus Torvalds + * Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 1999 + * SMP-safe vmalloc/vfree/ioremap, Tigran Aivazian <tigran@veritas.com>, May 2000 + * Major rework to support vmap/vunmap, Christoph Hellwig, SGI, August 2002 + * Numa awareness, Christoph Lameter, SGI, June 2005 + * Improving global KVA allocator, Uladzislau Rezki, Sony, May 2019 + */ + +#include <linux/vmalloc.h> +#include <linux/mm.h> +#include <linux/module.h> +#include <linux/highmem.h> +#include <linux/sched/signal.h> +#include <linux/slab.h> +#include <linux/spinlock.h> +#include <linux/interrupt.h> +#include <linux/proc_fs.h> +#include <linux/seq_file.h> +#include <linux/set_memory.h> +#include <linux/debugobjects.h> +#include <linux/kallsyms.h> +#include <linux/list.h> +#include <linux/notifier.h> +#include <linux/rbtree.h> +#include <linux/xarray.h> +#include <linux/io.h> +#include <linux/rcupdate.h> +#include <linux/pfn.h> +#include <linux/kmemleak.h> +#include <linux/atomic.h> +#include <linux/compiler.h> +#include <linux/memcontrol.h> +#include <linux/llist.h> +#include <linux/uio.h> +#include <linux/bitops.h> +#include <linux/rbtree_augmented.h> +#include <linux/overflow.h> +#include <linux/pgtable.h> +#include <linux/hugetlb.h> +#include <linux/sched/mm.h> +#include <asm/tlbflush.h> +#include <asm/shmparam.h> + +#define CREATE_TRACE_POINTS +#include <trace/events/vmalloc.h> + +#include "internal.h" +#include "pgalloc-track.h" + +#ifdef CONFIG_HAVE_ARCH_HUGE_VMAP +static unsigned int __ro_after_init ioremap_max_page_shift = BITS_PER_LONG - 1; + +static int __init set_nohugeiomap(char *str) +{ + ioremap_max_page_shift = PAGE_SHIFT; + return 0; +} +early_param("nohugeiomap", set_nohugeiomap); +#else /* CONFIG_HAVE_ARCH_HUGE_VMAP */ +static const unsigned int ioremap_max_page_shift = PAGE_SHIFT; +#endif /* CONFIG_HAVE_ARCH_HUGE_VMAP */ + +#ifdef CONFIG_HAVE_ARCH_HUGE_VMALLOC +static bool __ro_after_init vmap_allow_huge = true; + +static int __init set_nohugevmalloc(char *str) +{ + vmap_allow_huge = false; + return 0; +} +early_param("nohugevmalloc", set_nohugevmalloc); +#else /* CONFIG_HAVE_ARCH_HUGE_VMALLOC */ +static const bool vmap_allow_huge = false; +#endif /* CONFIG_HAVE_ARCH_HUGE_VMALLOC */ + +bool is_vmalloc_addr(const void *x) +{ + unsigned long addr = (unsigned long)kasan_reset_tag(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); + +/*** Page table manipulation functions ***/ +static int vmap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end, + phys_addr_t phys_addr, pgprot_t prot, + unsigned int max_page_shift, pgtbl_mod_mask *mask) +{ + pte_t *pte; + u64 pfn; + unsigned long size = PAGE_SIZE; + + pfn = phys_addr >> PAGE_SHIFT; + pte = pte_alloc_kernel_track(pmd, addr, mask); + if (!pte) + return -ENOMEM; + do { + BUG_ON(!pte_none(ptep_get(pte))); + +#ifdef CONFIG_HUGETLB_PAGE + size = arch_vmap_pte_range_map_size(addr, end, pfn, max_page_shift); + if (size != PAGE_SIZE) { + pte_t entry = pfn_pte(pfn, prot); + + entry = arch_make_huge_pte(entry, ilog2(size), 0); + set_huge_pte_at(&init_mm, addr, pte, entry, size); + pfn += PFN_DOWN(size); + continue; + } +#endif + set_pte_at(&init_mm, addr, pte, pfn_pte(pfn, prot)); + pfn++; + } while (pte += PFN_DOWN(size), addr += size, addr != end); + *mask |= PGTBL_PTE_MODIFIED; + return 0; +} + +static int vmap_try_huge_pmd(pmd_t *pmd, unsigned long addr, unsigned long end, + phys_addr_t phys_addr, pgprot_t prot, + unsigned int max_page_shift) +{ + if (max_page_shift < PMD_SHIFT) + return 0; + + if (!arch_vmap_pmd_supported(prot)) + return 0; + + if ((end - addr) != PMD_SIZE) + return 0; + + if (!IS_ALIGNED(addr, PMD_SIZE)) + return 0; + + if (!IS_ALIGNED(phys_addr, PMD_SIZE)) + return 0; + + if (pmd_present(*pmd) && !pmd_free_pte_page(pmd, addr)) + return 0; + + return pmd_set_huge(pmd, phys_addr, prot); +} + +static int vmap_pmd_range(pud_t *pud, unsigned long addr, unsigned long end, + phys_addr_t phys_addr, pgprot_t prot, + unsigned int max_page_shift, 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_try_huge_pmd(pmd, addr, next, phys_addr, prot, + max_page_shift)) { + *mask |= PGTBL_PMD_MODIFIED; + continue; + } + + if (vmap_pte_range(pmd, addr, next, phys_addr, prot, max_page_shift, mask)) + return -ENOMEM; + } while (pmd++, phys_addr += (next - addr), addr = next, addr != end); + return 0; +} + +static int vmap_try_huge_pud(pud_t *pud, unsigned long addr, unsigned long end, + phys_addr_t phys_addr, pgprot_t prot, + unsigned int max_page_shift) +{ + if (max_page_shift < PUD_SHIFT) + return 0; + + if (!arch_vmap_pud_supported(prot)) + return 0; + + if ((end - addr) != PUD_SIZE) + return 0; + + if (!IS_ALIGNED(addr, PUD_SIZE)) + return 0; + + if (!IS_ALIGNED(phys_addr, PUD_SIZE)) + return 0; + + if (pud_present(*pud) && !pud_free_pmd_page(pud, addr)) + return 0; + + return pud_set_huge(pud, phys_addr, prot); +} + +static int vmap_pud_range(p4d_t *p4d, unsigned long addr, unsigned long end, + phys_addr_t phys_addr, pgprot_t prot, + unsigned int max_page_shift, 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_try_huge_pud(pud, addr, next, phys_addr, prot, + max_page_shift)) { + *mask |= PGTBL_PUD_MODIFIED; + continue; + } + + if (vmap_pmd_range(pud, addr, next, phys_addr, prot, + max_page_shift, mask)) + return -ENOMEM; + } while (pud++, phys_addr += (next - addr), addr = next, addr != end); + return 0; +} + +static int vmap_try_huge_p4d(p4d_t *p4d, unsigned long addr, unsigned long end, + phys_addr_t phys_addr, pgprot_t prot, + unsigned int max_page_shift) +{ + if (max_page_shift < P4D_SHIFT) + return 0; + + if (!arch_vmap_p4d_supported(prot)) + return 0; + + if ((end - addr) != P4D_SIZE) + return 0; + + if (!IS_ALIGNED(addr, P4D_SIZE)) + return 0; + + if (!IS_ALIGNED(phys_addr, P4D_SIZE)) + return 0; + + if (p4d_present(*p4d) && !p4d_free_pud_page(p4d, addr)) + return 0; + + return p4d_set_huge(p4d, phys_addr, prot); +} + +static int vmap_p4d_range(pgd_t *pgd, unsigned long addr, unsigned long end, + phys_addr_t phys_addr, pgprot_t prot, + unsigned int max_page_shift, 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_try_huge_p4d(p4d, addr, next, phys_addr, prot, + max_page_shift)) { + *mask |= PGTBL_P4D_MODIFIED; + continue; + } + + if (vmap_pud_range(p4d, addr, next, phys_addr, prot, + max_page_shift, mask)) + return -ENOMEM; + } while (p4d++, phys_addr += (next - addr), addr = next, addr != end); + return 0; +} + +static int vmap_range_noflush(unsigned long addr, unsigned long end, + phys_addr_t phys_addr, pgprot_t prot, + unsigned int max_page_shift) +{ + pgd_t *pgd; + unsigned long start; + unsigned long next; + int err; + pgtbl_mod_mask mask = 0; + + might_sleep(); + BUG_ON(addr >= end); + + start = addr; + pgd = pgd_offset_k(addr); + do { + next = pgd_addr_end(addr, end); + err = vmap_p4d_range(pgd, addr, next, phys_addr, prot, + max_page_shift, &mask); + if (err) + break; + } while (pgd++, phys_addr += (next - addr), addr = next, addr != end); + + if (mask & ARCH_PAGE_TABLE_SYNC_MASK) + arch_sync_kernel_mappings(start, end); + + return err; +} + +int ioremap_page_range(unsigned long addr, unsigned long end, + phys_addr_t phys_addr, pgprot_t prot) +{ + int err; + + err = vmap_range_noflush(addr, end, phys_addr, pgprot_nx(prot), + ioremap_max_page_shift); + flush_cache_vmap(addr, end); + if (!err) + err = kmsan_ioremap_page_range(addr, end, phys_addr, prot, + ioremap_max_page_shift); + return err; +} + +static void vunmap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end, + pgtbl_mod_mask *mask) +{ + pte_t *pte; + + pte = pte_offset_kernel(pmd, addr); + do { + pte_t ptent = ptep_get_and_clear(&init_mm, addr, pte); + WARN_ON(!pte_none(ptent) && !pte_present(ptent)); + } while (pte++, addr += PAGE_SIZE, addr != end); + *mask |= PGTBL_PTE_MODIFIED; +} + +static void vunmap_pmd_range(pud_t *pud, unsigned long addr, unsigned long end, + pgtbl_mod_mask *mask) +{ + pmd_t *pmd; + unsigned long next; + int cleared; + + pmd = pmd_offset(pud, addr); + do { + next = pmd_addr_end(addr, end); + + cleared = pmd_clear_huge(pmd); + if (cleared || pmd_bad(*pmd)) + *mask |= PGTBL_PMD_MODIFIED; + + if (cleared) + continue; + if (pmd_none_or_clear_bad(pmd)) + continue; + vunmap_pte_range(pmd, addr, next, mask); + + cond_resched(); + } while (pmd++, addr = next, addr != end); +} + +static void vunmap_pud_range(p4d_t *p4d, unsigned long addr, unsigned long end, + pgtbl_mod_mask *mask) +{ + pud_t *pud; + unsigned long next; + int cleared; + + pud = pud_offset(p4d, addr); + do { + next = pud_addr_end(addr, end); + + cleared = pud_clear_huge(pud); + if (cleared || pud_bad(*pud)) + *mask |= PGTBL_PUD_MODIFIED; + + if (cleared) + continue; + if (pud_none_or_clear_bad(pud)) + continue; + vunmap_pmd_range(pud, addr, next, mask); + } while (pud++, addr = next, addr != end); +} + +static void vunmap_p4d_range(pgd_t *pgd, unsigned long addr, unsigned long end, + pgtbl_mod_mask *mask) +{ + p4d_t *p4d; + unsigned long next; + + p4d = p4d_offset(pgd, addr); + do { + next = p4d_addr_end(addr, end); + + p4d_clear_huge(p4d); + if (p4d_bad(*p4d)) + *mask |= PGTBL_P4D_MODIFIED; + + if (p4d_none_or_clear_bad(p4d)) + continue; + vunmap_pud_range(p4d, addr, next, mask); + } while (p4d++, addr = next, addr != end); +} + +/* + * vunmap_range_noflush is similar to vunmap_range, but does not + * flush caches or TLBs. + * + * The caller is responsible for calling flush_cache_vmap() before calling + * this function, and flush_tlb_kernel_range after it has returned + * successfully (and before the addresses are expected to cause a page fault + * or be re-mapped for something else, if TLB flushes are being delayed or + * coalesced). + * + * This is an internal function only. Do not use outside mm/. + */ +void __vunmap_range_noflush(unsigned long start, unsigned long end) +{ + unsigned long next; + pgd_t *pgd; + unsigned long addr = start; + pgtbl_mod_mask mask = 0; + + BUG_ON(addr >= end); + pgd = pgd_offset_k(addr); + do { + next = pgd_addr_end(addr, end); + if (pgd_bad(*pgd)) + mask |= PGTBL_PGD_MODIFIED; + if (pgd_none_or_clear_bad(pgd)) + continue; + vunmap_p4d_range(pgd, addr, next, &mask); + } while (pgd++, addr = next, addr != end); + + if (mask & ARCH_PAGE_TABLE_SYNC_MASK) + arch_sync_kernel_mappings(start, end); +} + +void vunmap_range_noflush(unsigned long start, unsigned long end) +{ + kmsan_vunmap_range_noflush(start, end); + __vunmap_range_noflush(start, end); +} + +/** + * vunmap_range - unmap kernel virtual addresses + * @addr: start of the VM area to unmap + * @end: end of the VM area to unmap (non-inclusive) + * + * Clears any present PTEs in the virtual address range, flushes TLBs and + * caches. Any subsequent access to the address before it has been re-mapped + * is a kernel bug. + */ +void vunmap_range(unsigned long addr, unsigned long end) +{ + flush_cache_vunmap(addr, end); + vunmap_range_noflush(addr, end); + flush_tlb_kernel_range(addr, end); +} + +static int vmap_pages_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(ptep_get(pte)))) + return -EBUSY; + if (WARN_ON(!page)) + return -ENOMEM; + if (WARN_ON(!pfn_valid(page_to_pfn(page)))) + return -EINVAL; + + 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_pages_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_pages_pte_range(pmd, addr, next, prot, pages, nr, mask)) + return -ENOMEM; + } while (pmd++, addr = next, addr != end); + return 0; +} + +static int vmap_pages_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_pages_pmd_range(pud, addr, next, prot, pages, nr, mask)) + return -ENOMEM; + } while (pud++, addr = next, addr != end); + return 0; +} + +static int vmap_pages_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_pages_pud_range(p4d, addr, next, prot, pages, nr, mask)) + return -ENOMEM; + } while (p4d++, addr = next, addr != end); + return 0; +} + +static int vmap_small_pages_range_noflush(unsigned long addr, unsigned long end, + pgprot_t prot, struct page **pages) +{ + unsigned long start = addr; + pgd_t *pgd; + unsigned long next; + 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_pages_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; +} + +/* + * vmap_pages_range_noflush is similar to vmap_pages_range, but does not + * flush caches. + * + * The caller is responsible for calling flush_cache_vmap() after this + * function returns successfully and before the addresses are accessed. + * + * This is an internal function only. Do not use outside mm/. + */ +int __vmap_pages_range_noflush(unsigned long addr, unsigned long end, + pgprot_t prot, struct page **pages, unsigned int page_shift) +{ + unsigned int i, nr = (end - addr) >> PAGE_SHIFT; + + WARN_ON(page_shift < PAGE_SHIFT); + + if (!IS_ENABLED(CONFIG_HAVE_ARCH_HUGE_VMALLOC) || + page_shift == PAGE_SHIFT) + return vmap_small_pages_range_noflush(addr, end, prot, pages); + + for (i = 0; i < nr; i += 1U << (page_shift - PAGE_SHIFT)) { + int err; + + err = vmap_range_noflush(addr, addr + (1UL << page_shift), + page_to_phys(pages[i]), prot, + page_shift); + if (err) + return err; + + addr += 1UL << page_shift; + } + + return 0; +} + +int vmap_pages_range_noflush(unsigned long addr, unsigned long end, + pgprot_t prot, struct page **pages, unsigned int page_shift) +{ + int ret = kmsan_vmap_pages_range_noflush(addr, end, prot, pages, + page_shift); + + if (ret) + return ret; + return __vmap_pages_range_noflush(addr, end, prot, pages, page_shift); +} + +/** + * vmap_pages_range - map pages to a kernel virtual address + * @addr: start of the VM area to map + * @end: end of the VM area to map (non-inclusive) + * @prot: page protection flags to use + * @pages: pages to map (always PAGE_SIZE pages) + * @page_shift: maximum shift that the pages may be mapped with, @pages must + * be aligned and contiguous up to at least this shift. + * + * RETURNS: + * 0 on success, -errno on failure. + */ +static int vmap_pages_range(unsigned long addr, unsigned long end, + pgprot_t prot, struct page **pages, unsigned int page_shift) +{ + int err; + + err = vmap_pages_range_noflush(addr, end, prot, pages, page_shift); + flush_cache_vmap(addr, end); + return err; +} + +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)kasan_reset_tag(x); + if (addr >= MODULES_VADDR && addr < MODULES_END) + return 1; +#endif + return is_vmalloc_addr(x); +} +EXPORT_SYMBOL_GPL(is_vmalloc_or_module_addr); + +/* + * Walk a vmap address to the struct page it maps. Huge vmap mappings will + * return the tail page that corresponds to the base page address, which + * matches small vmap mappings. + */ +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; + if (WARN_ON_ONCE(pgd_leaf(*pgd))) + return NULL; /* XXX: no allowance for huge pgd */ + if (WARN_ON_ONCE(pgd_bad(*pgd))) + return NULL; + + p4d = p4d_offset(pgd, addr); + if (p4d_none(*p4d)) + return NULL; + if (p4d_leaf(*p4d)) + return p4d_page(*p4d) + ((addr & ~P4D_MASK) >> PAGE_SHIFT); + if (WARN_ON_ONCE(p4d_bad(*p4d))) + return NULL; + + pud = pud_offset(p4d, addr); + if (pud_none(*pud)) + return NULL; + if (pud_leaf(*pud)) + return pud_page(*pud) + ((addr & ~PUD_MASK) >> PAGE_SHIFT); + if (WARN_ON_ONCE(pud_bad(*pud))) + return NULL; + + pmd = pmd_offset(pud, addr); + if (pmd_none(*pmd)) + return NULL; + if (pmd_leaf(*pmd)) + return pmd_page(*pmd) + ((addr & ~PMD_MASK) >> PAGE_SHIFT); + if (WARN_ON_ONCE(pmd_bad(*pmd))) + return NULL; + + ptep = pte_offset_kernel(pmd, addr); + pte = ptep_get(ptep); + if (pte_present(pte)) + page = pte_page(pte); + + 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 struct rb_root vmap_area_root = RB_ROOT; +static bool vmap_initialized __read_mostly; + +static struct rb_root purge_vmap_area_root = RB_ROOT; +static LIST_HEAD(purge_vmap_area_list); +static DEFINE_SPINLOCK(purge_vmap_area_lock); + +/* + * 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; +} + +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 reclaim_and_purge_vmap_areas(void); +static BLOCKING_NOTIFIER_HEAD(vmap_notify_list); +static void drain_vmap_area_work(struct work_struct *work); +static DECLARE_WORK(drain_vmap_work, drain_vmap_area_work); + +static atomic_long_t nr_vmalloc_pages; + +unsigned long vmalloc_nr_pages(void) +{ + return atomic_long_read(&nr_vmalloc_pages); +} + +/* Look up the first VA which satisfies addr < va_end, NULL if none. */ +static struct vmap_area *find_vmap_area_exceed_addr(unsigned long addr) +{ + struct vmap_area *va = NULL; + struct rb_node *n = vmap_area_root.rb_node; + + addr = (unsigned long)kasan_reset_tag((void *)addr); + + while (n) { + struct vmap_area *tmp; + + tmp = rb_entry(n, struct vmap_area, rb_node); + if (tmp->va_end > addr) { + va = tmp; + if (tmp->va_start <= addr) + break; + + n = n->rb_left; + } else + n = n->rb_right; + } + + return va; +} + +static struct vmap_area *__find_vmap_area(unsigned long addr, struct rb_root *root) +{ + struct rb_node *n = root->rb_node; + + addr = (unsigned long)kasan_reset_tag((void *)addr); + + while (n) { + struct vmap_area *va; + + va = rb_entry(n, struct vmap_area, rb_node); + if (addr < va->va_start) + n = n->rb_left; + else if (addr >= va->va_end) + n = n->rb_right; + else + return va; + } + + return NULL; +} + +/* + * This function returns back addresses of parent node + * and its left or right link for further processing. + * + * Otherwise NULL is returned. In that case all further + * steps regarding inserting of conflicting overlap range + * have to be declined and actually considered as a bug. + */ +static __always_inline struct rb_node ** +find_va_links(struct vmap_area *va, + struct rb_root *root, struct rb_node *from, + struct rb_node **parent) +{ + struct vmap_area *tmp_va; + struct rb_node **link; + + if (root) { + link = &root->rb_node; + if (unlikely(!*link)) { + *parent = NULL; + return link; + } + } else { + link = &from; + } + + /* + * Go to the bottom of the tree. When we hit the last point + * we end up with parent rb_node and correct direction, i name + * it link, where the new va->rb_node will be attached to. + */ + do { + tmp_va = rb_entry(*link, struct vmap_area, rb_node); + + /* + * During the traversal we also do some sanity check. + * Trigger the BUG() if there are sides(left/right) + * or full overlaps. + */ + if (va->va_end <= tmp_va->va_start) + link = &(*link)->rb_left; + else if (va->va_start >= tmp_va->va_end) + link = &(*link)->rb_right; + else { + WARN(1, "vmalloc bug: 0x%lx-0x%lx overlaps with 0x%lx-0x%lx\n", + va->va_start, va->va_end, tmp_va->va_start, tmp_va->va_end); + + return NULL; + } + } while (*link); + + *parent = &tmp_va->rb_node; + return link; +} + +static __always_inline struct list_head * +get_va_next_sibling(struct rb_node *parent, struct rb_node **link) +{ + struct list_head *list; + + if (unlikely(!parent)) + /* + * The red-black tree where we try to find VA neighbors + * before merging or inserting is empty, i.e. it means + * there is no free vmap space. Normally it does not + * happen but we handle this case anyway. + */ + return NULL; + + list = &rb_entry(parent, struct vmap_area, rb_node)->list; + return (&parent->rb_right == link ? list->next : list); +} + +static __always_inline void +__link_va(struct vmap_area *va, struct rb_root *root, + struct rb_node *parent, struct rb_node **link, + struct list_head *head, bool augment) +{ + /* + * 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 (augment) { + /* + * 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 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 +link_va(struct vmap_area *va, struct rb_root *root, + struct rb_node *parent, struct rb_node **link, + struct list_head *head) +{ + __link_va(va, root, parent, link, head, false); +} + +static __always_inline void +link_va_augment(struct vmap_area *va, struct rb_root *root, + struct rb_node *parent, struct rb_node **link, + struct list_head *head) +{ + __link_va(va, root, parent, link, head, true); +} + +static __always_inline void +__unlink_va(struct vmap_area *va, struct rb_root *root, bool augment) +{ + if (WARN_ON(RB_EMPTY_NODE(&va->rb_node))) + return; + + if (augment) + rb_erase_augmented(&va->rb_node, + root, &free_vmap_area_rb_augment_cb); + else + rb_erase(&va->rb_node, root); + + list_del_init(&va->list); + RB_CLEAR_NODE(&va->rb_node); +} + +static __always_inline void +unlink_va(struct vmap_area *va, struct rb_root *root) +{ + __unlink_va(va, root, false); +} + +static __always_inline void +unlink_va_augment(struct vmap_area *va, struct rb_root *root) +{ + __unlink_va(va, root, true); +} + +#if DEBUG_AUGMENT_PROPAGATE_CHECK +/* + * 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)); +} + +static void +augment_tree_propagate_check(void) +{ + struct vmap_area *va; + unsigned long computed_size; + + list_for_each_entry(va, &free_vmap_area_list, list) { + computed_size = compute_subtree_max_size(va); + if (computed_size != va->subtree_max_size) + pr_emerg("tree is corrupted: %lu, %lu\n", + va_size(va), va->subtree_max_size); + } +} +#endif + +/* + * This function populates subtree_max_size from bottom to upper + * levels starting from VA point. The propagation must be done + * when VA size is modified by changing its va_start/va_end. Or + * in case of newly inserting of VA to the tree. + * + * It means that __augment_tree_propagate_from() must be called: + * - After VA has been inserted to the tree(free path); + * - After VA has been shrunk(allocation path); + * - After VA has been increased(merging path). + * + * Please note that, it does not mean that upper parent nodes + * and their subtree_max_size are recalculated all the time up + * to the root node. + * + * 4--8 + * /\ + * / \ + * / \ + * 2--2 8--8 + * + * For example if we modify the node 4, shrinking it to 2, then + * no any modification is required. If we shrink the node 2 to 1 + * its subtree_max_size is updated only, and set to 1. If we shrink + * the node 8 to 6, then its subtree_max_size is set to 6 and parent + * node becomes 4--6. + */ +static __always_inline void +augment_tree_propagate_from(struct vmap_area *va) +{ + /* + * Populate the tree from bottom towards the root until + * the calculated maximum available size of checked node + * is equal to its current one. + */ + free_vmap_area_rb_augment_cb_propagate(&va->rb_node, NULL); + +#if DEBUG_AUGMENT_PROPAGATE_CHECK + augment_tree_propagate_check(); +#endif +} + +static void +insert_vmap_area(struct vmap_area *va, + struct rb_root *root, struct list_head *head) +{ + struct rb_node **link; + struct rb_node *parent; + + link = find_va_links(va, root, NULL, &parent); + if (link) + link_va(va, root, parent, link, head); +} + +static void +insert_vmap_area_augment(struct vmap_area *va, + struct rb_node *from, struct rb_root *root, + struct list_head *head) +{ + struct rb_node **link; + struct rb_node *parent; + + if (from) + link = find_va_links(va, NULL, from, &parent); + else + link = find_va_links(va, root, NULL, &parent); + + if (link) { + link_va_augment(va, root, parent, link, head); + augment_tree_propagate_from(va); + } +} + +/* + * Merge de-allocated chunk of VA memory with previous + * and next free blocks. If coalesce is not done a new + * free area is inserted. If VA has been merged, it is + * freed. + * + * Please note, it can return NULL in case of overlap + * ranges, followed by WARN() report. Despite it is a + * buggy behaviour, a system can be alive and keep + * ongoing. + */ +static __always_inline struct vmap_area * +__merge_or_add_vmap_area(struct vmap_area *va, + struct rb_root *root, struct list_head *head, bool augment) +{ + struct vmap_area *sibling; + struct list_head *next; + struct rb_node **link; + struct rb_node *parent; + bool merged = false; + + /* + * Find a place in the tree where VA potentially will be + * inserted, unless it is merged with its sibling/siblings. + */ + link = find_va_links(va, root, NULL, &parent); + if (!link) + return NULL; + + /* + * Get next node of VA to check if merging can be done. + */ + next = get_va_next_sibling(parent, link); + if (unlikely(next == NULL)) + goto insert; + + /* + * start end + * | | + * |<------VA------>|<-----Next----->| + * | | + * start end + */ + if (next != head) { + sibling = list_entry(next, struct vmap_area, list); + if (sibling->va_start == va->va_end) { + sibling->va_start = va->va_start; + + /* Free vmap_area object. */ + kmem_cache_free(vmap_area_cachep, va); + + /* Point to the new merged area. */ + va = sibling; + merged = true; + } + } + + /* + * start end + * | | + * |<-----Prev----->|<------VA------>| + * | | + * start end + */ + if (next->prev != head) { + sibling = list_entry(next->prev, struct vmap_area, list); + if (sibling->va_end == va->va_start) { + /* + * If both neighbors are coalesced, it is important + * to unlink the "next" node first, followed by merging + * with "previous" one. Otherwise the tree might not be + * fully populated if a sibling's augmented value is + * "normalized" because of rotation operations. + */ + if (merged) + __unlink_va(va, root, augment); + + sibling->va_end = va->va_end; + + /* Free vmap_area object. */ + kmem_cache_free(vmap_area_cachep, va); + + /* Point to the new merged area. */ + va = sibling; + merged = true; + } + } + +insert: + if (!merged) + __link_va(va, root, parent, link, head, augment); + + return va; +} + +static __always_inline struct vmap_area * +merge_or_add_vmap_area(struct vmap_area *va, + struct rb_root *root, struct list_head *head) +{ + return __merge_or_add_vmap_area(va, root, head, false); +} + +static __always_inline struct vmap_area * +merge_or_add_vmap_area_augment(struct vmap_area *va, + struct rb_root *root, struct list_head *head) +{ + va = __merge_or_add_vmap_area(va, root, head, true); + if (va) + 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. Please note, with an alignment bigger than PAGE_SIZE, + * a search length is adjusted to account for worst case alignment + * overhead. + */ +static __always_inline struct vmap_area * +find_vmap_lowest_match(struct rb_root *root, unsigned long size, + unsigned long align, unsigned long vstart, bool adjust_search_size) +{ + struct vmap_area *va; + struct rb_node *node; + unsigned long length; + + /* Start from the root. */ + node = root->rb_node; + + /* Adjust the search size for alignment overhead. */ + length = adjust_search_size ? size + align - 1 : size; + + 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 + * due to "vstart" restriction or an alignment overhead + * that is bigger then PAGE_SIZE. + */ + 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) { + /* + * Shift the vstart forward. Please note, we update it with + * parent's start address adding "1" because we do not want + * to enter same sub-tree after it has already been checked + * and no suitable free block found there. + */ + vstart = va->va_start + 1; + 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(struct list_head *head, unsigned long size, + unsigned long align, unsigned long vstart) +{ + struct vmap_area *va; + + list_for_each_entry(va, head, list) { + if (!is_within_this_va(va, size, align, vstart)) + continue; + + return va; + } + + return NULL; +} + +static void +find_vmap_lowest_match_check(struct rb_root *root, struct list_head *head, + unsigned long size, unsigned long align) +{ + 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(root, size, align, vstart, false); + va_2 = find_vmap_lowest_linear_match(head, size, align, 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 rb_root *root, struct list_head *head, + struct vmap_area *va, unsigned long nva_start_addr, + unsigned long size) +{ + struct vmap_area *lva = NULL; + enum fit_type type = classify_va_fit_type(va, nva_start_addr, size); + + if (type == FL_FIT_TYPE) { + /* + * No need to split VA, it fully fits. + * + * | | + * V NVA V + * |---------------| + */ + unlink_va_augment(va, 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, root, head); + } + + 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(struct rb_root *root, struct list_head *head, + unsigned long size, unsigned long align, + unsigned long vstart, unsigned long vend) +{ + bool adjust_search_size = true; + unsigned long nva_start_addr; + struct vmap_area *va; + int ret; + + /* + * Do not adjust when: + * a) align <= PAGE_SIZE, because it does not make any sense. + * All blocks(their start addresses) are at least PAGE_SIZE + * aligned anyway; + * b) a short range where a requested size corresponds to exactly + * specified [vstart:vend] interval and an alignment > PAGE_SIZE. + * With adjusted search length an allocation would not succeed. + */ + if (align <= PAGE_SIZE || (align > PAGE_SIZE && (vend - vstart) == size)) + adjust_search_size = false; + + va = find_vmap_lowest_match(root, size, align, vstart, adjust_search_size); + 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; + + /* Update the free vmap_area. */ + ret = adjust_va_to_fit_type(root, head, va, nva_start_addr, size); + if (WARN_ON_ONCE(ret)) + return vend; + +#if DEBUG_AUGMENT_LOWEST_MATCH_CHECK + find_vmap_lowest_match_check(root, head, size, align); +#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_augment(va, &free_vmap_area_root, &free_vmap_area_list); + spin_unlock(&free_vmap_area_lock); +} + +static inline void +preload_this_cpu_lock(spinlock_t *lock, gfp_t gfp_mask, int node) +{ + struct vmap_area *va = NULL; + + /* + * Preload this CPU with one extra vmap_area object. It is used + * when fit type of free area is NE_FIT_TYPE. It guarantees that + * a CPU that does an allocation is preloaded. + * + * We do it 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. + */ + if (!this_cpu_read(ne_fit_preload_node)) + va = kmem_cache_alloc_node(vmap_area_cachep, gfp_mask, node); + + spin_lock(lock); + + if (va && __this_cpu_cmpxchg(ne_fit_preload_node, NULL, va)) + kmem_cache_free(vmap_area_cachep, va); +} + +/* + * 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, + unsigned long va_flags) +{ + struct vmap_area *va; + unsigned long freed; + unsigned long addr; + int purged = 0; + int ret; + + if (unlikely(!size || offset_in_page(size) || !is_power_of_2(align))) + return ERR_PTR(-EINVAL); + + 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_lock(&free_vmap_area_lock, gfp_mask, node); + addr = __alloc_vmap_area(&free_vmap_area_root, &free_vmap_area_list, + size, align, vstart, vend); + spin_unlock(&free_vmap_area_lock); + + trace_alloc_vmap_area(addr, size, align, vstart, vend, addr == vend); + + /* + * If an allocation fails, the "vend" address is + * returned. Therefore trigger the overflow path. + */ + if (unlikely(addr == vend)) + goto overflow; + + va->va_start = addr; + va->va_end = addr + size; + va->vm = NULL; + va->flags = va_flags; + + 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) { + reclaim_and_purge_vmap_areas(); + purged = 1; + goto retry; + } + + 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 critical section protected + * by this lock, 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); + +/* + * Purges all lazily-freed vmap areas. + */ +static bool __purge_vmap_area_lazy(unsigned long start, unsigned long end) +{ + unsigned long resched_threshold; + unsigned int num_purged_areas = 0; + struct list_head local_purge_list; + struct vmap_area *va, *n_va; + + lockdep_assert_held(&vmap_purge_lock); + + spin_lock(&purge_vmap_area_lock); + purge_vmap_area_root = RB_ROOT; + list_replace_init(&purge_vmap_area_list, &local_purge_list); + spin_unlock(&purge_vmap_area_lock); + + if (unlikely(list_empty(&local_purge_list))) + goto out; + + start = min(start, + list_first_entry(&local_purge_list, + struct vmap_area, list)->va_start); + + end = max(end, + list_last_entry(&local_purge_list, + struct vmap_area, list)->va_end); + + flush_tlb_kernel_range(start, end); + resched_threshold = lazy_max_pages() << 1; + + spin_lock(&free_vmap_area_lock); + list_for_each_entry_safe(va, n_va, &local_purge_list, 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_augment(va, &free_vmap_area_root, + &free_vmap_area_list); + + if (!va) + continue; + + if (is_vmalloc_or_module_addr((void *)orig_start)) + kasan_release_vmalloc(orig_start, orig_end, + va->va_start, va->va_end); + + atomic_long_sub(nr, &vmap_lazy_nr); + num_purged_areas++; + + if (atomic_long_read(&vmap_lazy_nr) < resched_threshold) + cond_resched_lock(&free_vmap_area_lock); + } + spin_unlock(&free_vmap_area_lock); + +out: + trace_purge_vmap_area_lazy(start, end, num_purged_areas); + return num_purged_areas > 0; +} + +/* + * Reclaim vmap areas by purging fragmented blocks and purge_vmap_area_list. + */ +static void reclaim_and_purge_vmap_areas(void) + +{ + mutex_lock(&vmap_purge_lock); + purge_fragmented_blocks_allcpus(); + __purge_vmap_area_lazy(ULONG_MAX, 0); + mutex_unlock(&vmap_purge_lock); +} + +static void drain_vmap_area_work(struct work_struct *work) +{ + unsigned long nr_lazy; + + do { + mutex_lock(&vmap_purge_lock); + __purge_vmap_area_lazy(ULONG_MAX, 0); + mutex_unlock(&vmap_purge_lock); + + /* Recheck if further work is required. */ + nr_lazy = atomic_long_read(&vmap_lazy_nr); + } while (nr_lazy > lazy_max_pages()); +} + +/* + * Free a vmap area, caller ensuring that the area has been unmapped, + * unlinked 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_max = lazy_max_pages(); + unsigned long va_start = va->va_start; + unsigned long nr_lazy; + + if (WARN_ON_ONCE(!list_empty(&va->list))) + return; + + nr_lazy = atomic_long_add_return((va->va_end - va->va_start) >> + PAGE_SHIFT, &vmap_lazy_nr); + + /* + * Merge or place it to the purge tree/list. + */ + spin_lock(&purge_vmap_area_lock); + merge_or_add_vmap_area(va, + &purge_vmap_area_root, &purge_vmap_area_list); + spin_unlock(&purge_vmap_area_lock); + + trace_free_vmap_area_noflush(va_start, nr_lazy, nr_lazy_max); + + /* After this point, we may free va at any time */ + if (unlikely(nr_lazy > nr_lazy_max)) + schedule_work(&drain_vmap_work); +} + +/* + * 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); + vunmap_range_noflush(va->va_start, va->va_end); + if (debug_pagealloc_enabled_static()) + flush_tlb_kernel_range(va->va_start, va->va_end); + + free_vmap_area_noflush(va); +} + +struct vmap_area *find_vmap_area(unsigned long addr) +{ + struct vmap_area *va; + + spin_lock(&vmap_area_lock); + va = __find_vmap_area(addr, &vmap_area_root); + spin_unlock(&vmap_area_lock); + + return va; +} + +static struct vmap_area *find_unlink_vmap_area(unsigned long addr) +{ + struct vmap_area *va; + + spin_lock(&vmap_area_lock); + va = __find_vmap_area(addr, &vmap_area_root); + if (va) + unlink_va(va, &vmap_area_root); + 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) + +/* + * Purge threshold to prevent overeager purging of fragmented blocks for + * regular operations: Purge if vb->free is less than 1/4 of the capacity. + */ +#define VMAP_PURGE_THRESHOLD (VMAP_BBMAP_BITS / 4) + +#define VMAP_RAM 0x1 /* indicates vm_map_ram area*/ +#define VMAP_BLOCK 0x2 /* mark out the vmap_block sub-type*/ +#define VMAP_FLAGS_MASK 0x3 + +struct vmap_block_queue { + spinlock_t lock; + struct list_head free; + + /* + * An xarray requires an extra memory dynamically to + * be allocated. If it is an issue, we can use rb-tree + * instead. + */ + struct xarray vmap_blocks; +}; + +struct vmap_block { + spinlock_t lock; + struct vmap_area *va; + unsigned long free, dirty; + DECLARE_BITMAP(used_map, VMAP_BBMAP_BITS); + 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); + +/* + * In order to fast access to any "vmap_block" associated with a + * specific address, we use a hash. + * + * A per-cpu vmap_block_queue is used in both ways, to serialize + * an access to free block chains among CPUs(alloc path) and it + * also acts as a vmap_block hash(alloc/free paths). It means we + * overload it, since we already have the per-cpu array which is + * used as a hash table. When used as a hash a 'cpu' passed to + * per_cpu() is not actually a CPU but rather a hash index. + * + * A hash function is addr_to_vb_xa() which hashes any address + * to a specific index(in a hash) it belongs to. This then uses a + * per_cpu() macro to access an array with generated index. + * + * An example: + * + * CPU_1 CPU_2 CPU_0 + * | | | + * V V V + * 0 10 20 30 40 50 60 + * |------|------|------|------|------|------|...<vmap address space> + * CPU0 CPU1 CPU2 CPU0 CPU1 CPU2 + * + * - CPU_1 invokes vm_unmap_ram(6), 6 belongs to CPU0 zone, thus + * it access: CPU0/INDEX0 -> vmap_blocks -> xa_lock; + * + * - CPU_2 invokes vm_unmap_ram(11), 11 belongs to CPU1 zone, thus + * it access: CPU1/INDEX1 -> vmap_blocks -> xa_lock; + * + * - CPU_0 invokes vm_unmap_ram(20), 20 belongs to CPU2 zone, thus + * it access: CPU2/INDEX2 -> vmap_blocks -> xa_lock. + * + * This technique almost always avoids lock contention on insert/remove, + * however xarray spinlocks protect against any contention that remains. + */ +static struct xarray * +addr_to_vb_xa(unsigned long addr) +{ + int index = (addr / VMAP_BLOCK_SIZE) % num_possible_cpus(); + + return &per_cpu(vmap_block_queue, index).vmap_blocks; +} + +/* + * We should probably have a fallback mechanism to allocate virtual memory + * out of partially filled vmap blocks. However vmap block sizing should be + * fairly reasonable according to the vmalloc size, so it shouldn't be a + * big problem. + */ + +static unsigned long addr_to_vb_idx(unsigned long addr) +{ + addr -= VMALLOC_START & ~(VMAP_BLOCK_SIZE-1); + addr /= VMAP_BLOCK_SIZE; + return addr; +} + +static void *vmap_block_vaddr(unsigned long va_start, unsigned long pages_off) +{ + unsigned long addr; + + addr = va_start + (pages_off << PAGE_SHIFT); + BUG_ON(addr_to_vb_idx(addr) != addr_to_vb_idx(va_start)); + return (void *)addr; +} + +/** + * new_vmap_block - allocates new vmap_block and occupies 2^order pages in this + * block. Of course pages number can't exceed VMAP_BBMAP_BITS + * @order: how many 2^order pages should be occupied in newly allocated block + * @gfp_mask: flags for the page level allocator + * + * Return: virtual address in a newly allocated block or ERR_PTR(-errno) + */ +static void *new_vmap_block(unsigned int order, gfp_t gfp_mask) +{ + struct vmap_block_queue *vbq; + struct vmap_block *vb; + struct vmap_area *va; + struct xarray *xa; + 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, + VMAP_RAM|VMAP_BLOCK); + if (IS_ERR(va)) { + kfree(vb); + return ERR_CAST(va); + } + + vaddr = vmap_block_vaddr(va->va_start, 0); + spin_lock_init(&vb->lock); + vb->va = va; + /* At least something should be left free */ + BUG_ON(VMAP_BBMAP_BITS <= (1UL << order)); + bitmap_zero(vb->used_map, VMAP_BBMAP_BITS); + vb->free = VMAP_BBMAP_BITS - (1UL << order); + vb->dirty = 0; + vb->dirty_min = VMAP_BBMAP_BITS; + vb->dirty_max = 0; + bitmap_set(vb->used_map, 0, (1UL << order)); + INIT_LIST_HEAD(&vb->free_list); + + xa = addr_to_vb_xa(va->va_start); + vb_idx = addr_to_vb_idx(va->va_start); + err = xa_insert(xa, vb_idx, vb, gfp_mask); + if (err) { + kfree(vb); + free_vmap_area(va); + return ERR_PTR(err); + } + + vbq = raw_cpu_ptr(&vmap_block_queue); + spin_lock(&vbq->lock); + list_add_tail_rcu(&vb->free_list, &vbq->free); + spin_unlock(&vbq->lock); + + return vaddr; +} + +static void free_vmap_block(struct vmap_block *vb) +{ + struct vmap_block *tmp; + struct xarray *xa; + + xa = addr_to_vb_xa(vb->va->va_start); + tmp = xa_erase(xa, addr_to_vb_idx(vb->va->va_start)); + BUG_ON(tmp != vb); + + spin_lock(&vmap_area_lock); + unlink_va(vb->va, &vmap_area_root); + spin_unlock(&vmap_area_lock); + + free_vmap_area_noflush(vb->va); + kfree_rcu(vb, rcu_head); +} + +static bool purge_fragmented_block(struct vmap_block *vb, + struct vmap_block_queue *vbq, struct list_head *purge_list, + bool force_purge) +{ + if (vb->free + vb->dirty != VMAP_BBMAP_BITS || + vb->dirty == VMAP_BBMAP_BITS) + return false; + + /* Don't overeagerly purge usable blocks unless requested */ + if (!(force_purge || vb->free < VMAP_PURGE_THRESHOLD)) + return false; + + /* prevent further allocs after releasing lock */ + WRITE_ONCE(vb->free, 0); + /* prevent purging it again */ + WRITE_ONCE(vb->dirty, VMAP_BBMAP_BITS); + vb->dirty_min = 0; + vb->dirty_max = VMAP_BBMAP_BITS; + spin_lock(&vbq->lock); + list_del_rcu(&vb->free_list); + spin_unlock(&vbq->lock); + list_add_tail(&vb->purge, purge_list); + return true; +} + +static void free_purged_blocks(struct list_head *purge_list) +{ + struct vmap_block *vb, *n_vb; + + list_for_each_entry_safe(vb, n_vb, purge_list, purge) { + list_del(&vb->purge); + free_vmap_block(vb); + } +} + +static void purge_fragmented_blocks(int cpu) +{ + LIST_HEAD(purge); + struct vmap_block *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) { + unsigned long free = READ_ONCE(vb->free); + unsigned long dirty = READ_ONCE(vb->dirty); + + if (free + dirty != VMAP_BBMAP_BITS || + dirty == VMAP_BBMAP_BITS) + continue; + + spin_lock(&vb->lock); + purge_fragmented_block(vb, vbq, &purge, true); + spin_unlock(&vb->lock); + } + rcu_read_unlock(); + free_purged_blocks(&purge); +} + +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 = raw_cpu_ptr(&vmap_block_queue); + list_for_each_entry_rcu(vb, &vbq->free, free_list) { + unsigned long pages_off; + + if (READ_ONCE(vb->free) < (1UL << order)) + continue; + + 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); + WRITE_ONCE(vb->free, vb->free - (1UL << order)); + bitmap_set(vb->used_map, pages_off, (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; + } + + rcu_read_unlock(); + + /* Allocate new block if nothing was found */ + if (!vaddr) + vaddr = new_vmap_block(order, gfp_mask); + + return vaddr; +} + +static void vb_free(unsigned long addr, unsigned long size) +{ + unsigned long offset; + unsigned int order; + struct vmap_block *vb; + struct xarray *xa; + + 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; + + xa = addr_to_vb_xa(addr); + vb = xa_load(xa, addr_to_vb_idx(addr)); + + spin_lock(&vb->lock); + bitmap_clear(vb->used_map, offset, (1UL << order)); + spin_unlock(&vb->lock); + + vunmap_range_noflush(addr, addr + size); + + if (debug_pagealloc_enabled_static()) + flush_tlb_kernel_range(addr, addr + size); + + spin_lock(&vb->lock); + + /* Expand the not yet TLB flushed dirty range */ + vb->dirty_min = min(vb->dirty_min, offset); + vb->dirty_max = max(vb->dirty_max, offset + (1UL << order)); + + WRITE_ONCE(vb->dirty, 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) +{ + LIST_HEAD(purge_list); + int cpu; + + if (unlikely(!vmap_initialized)) + return; + + mutex_lock(&vmap_purge_lock); + + for_each_possible_cpu(cpu) { + struct vmap_block_queue *vbq = &per_cpu(vmap_block_queue, cpu); + struct vmap_block *vb; + unsigned long idx; + + rcu_read_lock(); + xa_for_each(&vbq->vmap_blocks, idx, vb) { + spin_lock(&vb->lock); + + /* + * Try to purge a fragmented block first. If it's + * not purgeable, check whether there is dirty + * space to be flushed. + */ + if (!purge_fragmented_block(vb, vbq, &purge_list, false) && + vb->dirty_max && vb->dirty != VMAP_BBMAP_BITS) { + 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); + + /* Prevent that this is flushed again */ + vb->dirty_min = VMAP_BBMAP_BITS; + vb->dirty_max = 0; + + flush = 1; + } + spin_unlock(&vb->lock); + } + rcu_read_unlock(); + } + free_purged_blocks(&purge_list); + + 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)kasan_reset_tag(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_unlink_vmap_area(addr); + if (WARN_ON_ONCE(!va)) + return; + + debug_check_no_locks_freed((void *)va->va_start, + (va->va_end - va->va_start)); + free_unmap_vmap_area(va); +} +EXPORT_SYMBOL(vm_unmap_ram); + +/** + * vm_map_ram - map pages linearly into kernel virtual address (vmalloc space) + * @pages: an array of pointers to the pages to be mapped + * @count: number of pages + * @node: prefer to allocate data structures on this node + * + * If you use this function for less than VMAP_MAX_ALLOC pages, it could be + * faster than vmap so it's good. But if you mix long-life and short-life + * objects with vm_map_ram(), it could consume lots of address space through + * fragmentation (especially on a 32bit machine). You could see failures in + * the end. Please use this function for short-lived objects. + * + * Returns: a pointer to the address that has been mapped, or %NULL on failure + */ +void *vm_map_ram(struct page **pages, unsigned int count, int node) +{ + unsigned long size = (unsigned long)count << PAGE_SHIFT; + unsigned long addr; + void *mem; + + if (likely(count <= VMAP_MAX_ALLOC)) { + mem = vb_alloc(size, GFP_KERNEL); + if (IS_ERR(mem)) + return NULL; + addr = (unsigned long)mem; + } else { + struct vmap_area *va; + va = alloc_vmap_area(size, PAGE_SIZE, + VMALLOC_START, VMALLOC_END, + node, GFP_KERNEL, VMAP_RAM); + if (IS_ERR(va)) + return NULL; + + addr = va->va_start; + mem = (void *)addr; + } + + if (vmap_pages_range(addr, addr + size, PAGE_KERNEL, + pages, PAGE_SHIFT) < 0) { + vm_unmap_ram(mem, count); + return NULL; + } + + /* + * Mark the pages as accessible, now that they are mapped. + * With hardware tag-based KASAN, marking is skipped for + * non-VM_ALLOC mappings, see __kasan_unpoison_vmalloc(). + */ + mem = kasan_unpoison_vmalloc(mem, size, KASAN_VMALLOC_PROT_NORMAL); + + return mem; +} +EXPORT_SYMBOL(vm_map_ram); + +static struct vm_struct *vmlist __initdata; + +static inline unsigned int vm_area_page_order(struct vm_struct *vm) +{ +#ifdef CONFIG_HAVE_ARCH_HUGE_VMALLOC + return vm->page_order; +#else + return 0; +#endif +} + +static inline void set_vm_area_page_order(struct vm_struct *vm, unsigned int order) +{ +#ifdef CONFIG_HAVE_ARCH_HUGE_VMALLOC + vm->page_order = order; +#else + BUG_ON(order != 0); +#endif +} + +/** + * 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) +{ + unsigned long addr = ALIGN(VMALLOC_START, align); + struct vm_struct *cur, **p; + + BUG_ON(vmap_initialized); + + for (p = &vmlist; (cur = *p) != NULL; p = &cur->next) { + if ((unsigned long)cur->addr - addr >= vm->size) + break; + addr = ALIGN((unsigned long)cur->addr + cur->size, align); + } + + BUG_ON(addr > VMALLOC_END - vm->size); + vm->addr = (void *)addr; + vm->next = *p; + *p = vm; + kasan_populate_early_vm_area_shadow(vm->addr, vm->size); +} + +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); + } + } +} + +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 shift, 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 = ALIGN(size, 1ul << shift); + 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, 0); + if (IS_ERR(va)) { + kfree(area); + return NULL; + } + + setup_vmalloc_vm(area, va, flags, caller); + + /* + * Mark pages for non-VM_ALLOC mappings as accessible. Do it now as a + * best-effort approach, as they can be mapped outside of vmalloc code. + * For VM_ALLOC mappings, the pages are marked as accessible after + * getting mapped in __vmalloc_node_range(). + * With hardware tag-based KASAN, marking is skipped for + * non-VM_ALLOC mappings, see __kasan_unpoison_vmalloc(). + */ + if (!(flags & VM_ALLOC)) + area->addr = kasan_unpoison_vmalloc(area->addr, requested_size, + KASAN_VMALLOC_PROT_NORMAL); + + 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, PAGE_SHIFT, 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, PAGE_SHIFT, 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, PAGE_SHIFT, flags, + VMALLOC_START, VMALLOC_END, + NUMA_NO_NODE, GFP_KERNEL, caller); +} + +/** + * find_vm_area - find a continuous kernel virtual area + * @addr: base address + * + * Search for the kernel VM area starting at @addr, and return it. + * It is up to the caller to do all required locking to keep the returned + * pointer valid. + * + * Return: the area descriptor on success or %NULL on failure. + */ +struct vm_struct *find_vm_area(const void *addr) +{ + struct vmap_area *va; + + va = find_vmap_area((unsigned long)addr); + if (!va) + return NULL; + + return va->vm; +} + +/** + * remove_vm_area - find and remove a continuous kernel virtual area + * @addr: base address + * + * Search for the kernel VM area starting at @addr, and remove it. + * This function returns the found VM area, but using it is NOT safe + * on SMP machines, except for its size or flags. + * + * Return: the area descriptor on success or %NULL on failure. + */ +struct vm_struct *remove_vm_area(const void *addr) +{ + struct vmap_area *va; + struct vm_struct *vm; + + might_sleep(); + + if (WARN(!PAGE_ALIGNED(addr), "Trying to vfree() bad address (%p)\n", + addr)) + return NULL; + + va = find_unlink_vmap_area((unsigned long)addr); + if (!va || !va->vm) + return NULL; + vm = va->vm; + + debug_check_no_locks_freed(vm->addr, get_vm_area_size(vm)); + debug_check_no_obj_freed(vm->addr, get_vm_area_size(vm)); + kasan_free_module_shadow(vm); + kasan_poison_vmalloc(vm->addr, get_vm_area_size(vm)); + + free_unmap_vmap_area(va); + return vm; +} + +static inline void set_area_direct_map(const struct vm_struct *area, + int (*set_direct_map)(struct page *page)) +{ + int i; + + /* HUGE_VMALLOC passes small pages to set_direct_map */ + for (i = 0; i < area->nr_pages; i++) + if (page_address(area->pages[i])) + set_direct_map(area->pages[i]); +} + +/* + * Flush the vm mapping and reset the direct map. + */ +static void vm_reset_perms(struct vm_struct *area) +{ + unsigned long start = ULONG_MAX, end = 0; + unsigned int page_order = vm_area_page_order(area); + int flush_dmap = 0; + int i; + + /* + * Find the start and end range of the direct mappings to make sure that + * the vm_unmap_aliases() flush includes the direct map. + */ + for (i = 0; i < area->nr_pages; i += 1U << page_order) { + unsigned long addr = (unsigned long)page_address(area->pages[i]); + + if (addr) { + unsigned long page_size; + + page_size = PAGE_SIZE << page_order; + 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 delayed_vfree_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)) + vfree(llnode); +} + +/** + * 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) +{ + struct vfree_deferred *p = raw_cpu_ptr(&vfree_deferred); + + BUG_ON(in_nmi()); + kmemleak_free(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. + */ + if (addr && llist_add((struct llist_node *)addr, &p->list)) + schedule_work(&p->wq); +} + +/** + * vfree - Release memory allocated by vmalloc() + * @addr: Memory base address + * + * Free the virtually continuous memory area starting at @addr, as obtained + * from one of the vmalloc() family of APIs. This will usually also free the + * physical memory underlying the virtual allocation, but that memory is + * reference counted, so it will not be freed until the last user goes away. + * + * If @addr is NULL, no operation is performed. + * + * Context: + * May sleep if called *not* from interrupt context. + * Must not be called in NMI context (strictly speaking, it could be + * if we have CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG, but making the calling + * conventions for vfree() arch-dependent would be a really bad idea). + */ +void vfree(const void *addr) +{ + struct vm_struct *vm; + int i; + + if (unlikely(in_interrupt())) { + vfree_atomic(addr); + return; + } + + BUG_ON(in_nmi()); + kmemleak_free(addr); + might_sleep(); + + if (!addr) + return; + + vm = remove_vm_area(addr); + if (unlikely(!vm)) { + WARN(1, KERN_ERR "Trying to vfree() nonexistent vm area (%p)\n", + addr); + return; + } + + if (unlikely(vm->flags & VM_FLUSH_RESET_PERMS)) + vm_reset_perms(vm); + for (i = 0; i < vm->nr_pages; i++) { + struct page *page = vm->pages[i]; + + BUG_ON(!page); + mod_memcg_page_state(page, MEMCG_VMALLOC, -1); + /* + * High-order allocs for huge vmallocs are split, so + * can be freed as an array of order-0 allocations + */ + __free_page(page); + cond_resched(); + } + atomic_long_sub(vm->nr_pages, &nr_vmalloc_pages); + kvfree(vm->pages); + kfree(vm); +} +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) +{ + struct vm_struct *vm; + + BUG_ON(in_interrupt()); + might_sleep(); + + if (!addr) + return; + vm = remove_vm_area(addr); + if (unlikely(!vm)) { + WARN(1, KERN_ERR "Trying to vunmap() nonexistent vm area (%p)\n", + addr); + return; + } + kfree(vm); +} +EXPORT_SYMBOL(vunmap); + +/** + * vmap - map an array of pages into virtually contiguous space + * @pages: array of page pointers + * @count: number of pages to map + * @flags: vm_area->flags + * @prot: page protection for the mapping + * + * Maps @count pages from @pages into contiguous kernel virtual space. + * If @flags contains %VM_MAP_PUT_PAGES the ownership of the pages array itself + * (which must be kmalloc or vmalloc memory) and one reference per pages in it + * are transferred from the caller to vmap(), and will be freed / dropped when + * vfree() is called on the return value. + * + * Return: the address of the area or %NULL on failure + */ +void *vmap(struct page **pages, unsigned int count, + unsigned long flags, pgprot_t prot) +{ + struct vm_struct *area; + unsigned long addr; + unsigned long size; /* In bytes */ + + might_sleep(); + + if (WARN_ON_ONCE(flags & VM_FLUSH_RESET_PERMS)) + return NULL; + + /* + * Your top guard is someone else's bottom guard. Not having a top + * guard compromises someone else's mappings too. + */ + if (WARN_ON_ONCE(flags & VM_NO_GUARD)) + flags &= ~VM_NO_GUARD; + + 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; + + addr = (unsigned long)area->addr; + if (vmap_pages_range(addr, addr + size, pgprot_nx(prot), + pages, PAGE_SHIFT) < 0) { + vunmap(area->addr); + return NULL; + } + + if (flags & VM_MAP_PUT_PAGES) { + area->pages = pages; + area->nr_pages = count; + } + return area->addr; +} +EXPORT_SYMBOL(vmap); + +#ifdef CONFIG_VMAP_PFN +struct vmap_pfn_data { + unsigned long *pfns; + pgprot_t prot; + unsigned int idx; +}; + +static int vmap_pfn_apply(pte_t *pte, unsigned long addr, void *private) +{ + struct vmap_pfn_data *data = private; + unsigned long pfn = data->pfns[data->idx]; + pte_t ptent; + + if (WARN_ON_ONCE(pfn_valid(pfn))) + return -EINVAL; + + ptent = pte_mkspecial(pfn_pte(pfn, data->prot)); + set_pte_at(&init_mm, addr, pte, ptent); + + data->idx++; + return 0; +} + +/** + * vmap_pfn - map an array of PFNs into virtually contiguous space + * @pfns: array of PFNs + * @count: number of pages to map + * @prot: page protection for the mapping + * + * Maps @count PFNs from @pfns into contiguous kernel virtual space and returns + * the start address of the mapping. + */ +void *vmap_pfn(unsigned long *pfns, unsigned int count, pgprot_t prot) +{ + struct vmap_pfn_data data = { .pfns = pfns, .prot = pgprot_nx(prot) }; + struct vm_struct *area; + + area = get_vm_area_caller(count * PAGE_SIZE, VM_IOREMAP, + __builtin_return_address(0)); + if (!area) + return NULL; + if (apply_to_page_range(&init_mm, (unsigned long)area->addr, + count * PAGE_SIZE, vmap_pfn_apply, &data)) { + free_vm_area(area); + return NULL; + } + + flush_cache_vmap((unsigned long)area->addr, + (unsigned long)area->addr + count * PAGE_SIZE); + + return area->addr; +} +EXPORT_SYMBOL_GPL(vmap_pfn); +#endif /* CONFIG_VMAP_PFN */ + +static inline unsigned int +vm_area_alloc_pages(gfp_t gfp, int nid, + unsigned int order, unsigned int nr_pages, struct page **pages) +{ + unsigned int nr_allocated = 0; + gfp_t alloc_gfp = gfp; + bool nofail = false; + struct page *page; + int i; + + /* + * For order-0 pages we make use of bulk allocator, if + * the page array is partly or not at all populated due + * to fails, fallback to a single page allocator that is + * more permissive. + */ + if (!order) { + /* bulk allocator doesn't support nofail req. officially */ + gfp_t bulk_gfp = gfp & ~__GFP_NOFAIL; + + while (nr_allocated < nr_pages) { + unsigned int nr, nr_pages_request; + + /* + * A maximum allowed request is hard-coded and is 100 + * pages per call. That is done in order to prevent a + * long preemption off scenario in the bulk-allocator + * so the range is [1:100]. + */ + nr_pages_request = min(100U, nr_pages - nr_allocated); + + /* memory allocation should consider mempolicy, we can't + * wrongly use nearest node when nid == NUMA_NO_NODE, + * otherwise memory may be allocated in only one node, + * but mempolicy wants to alloc memory by interleaving. + */ + if (IS_ENABLED(CONFIG_NUMA) && nid == NUMA_NO_NODE) + nr = alloc_pages_bulk_array_mempolicy(bulk_gfp, + nr_pages_request, + pages + nr_allocated); + + else + nr = alloc_pages_bulk_array_node(bulk_gfp, nid, + nr_pages_request, + pages + nr_allocated); + + nr_allocated += nr; + cond_resched(); + + /* + * If zero or pages were obtained partly, + * fallback to a single page allocator. + */ + if (nr != nr_pages_request) + break; + } + } else if (gfp & __GFP_NOFAIL) { + /* + * Higher order nofail allocations are really expensive and + * potentially dangerous (pre-mature OOM, disruptive reclaim + * and compaction etc. + */ + alloc_gfp &= ~__GFP_NOFAIL; + nofail = true; + } + + /* High-order pages or fallback path if "bulk" fails. */ + while (nr_allocated < nr_pages) { + if (fatal_signal_pending(current)) + break; + + if (nid == NUMA_NO_NODE) + page = alloc_pages(alloc_gfp, order); + else + page = alloc_pages_node(nid, alloc_gfp, order); + if (unlikely(!page)) { + if (!nofail) + break; + + /* fall back to the zero order allocations */ + alloc_gfp |= __GFP_NOFAIL; + order = 0; + continue; + } + + /* + * Higher order allocations must be able to be treated as + * indepdenent small pages by callers (as they can with + * small-page vmallocs). Some drivers do their own refcounting + * on vmalloc_to_page() pages, some use page->mapping, + * page->lru, etc. + */ + if (order) + split_page(page, order); + + /* + * Careful, we allocate and map page-order pages, but + * tracking is done per PAGE_SIZE page so as to keep the + * vm_struct APIs independent of the physical/mapped size. + */ + for (i = 0; i < (1U << order); i++) + pages[nr_allocated + i] = page + i; + + cond_resched(); + nr_allocated += 1U << order; + } + + return nr_allocated; +} + +static void *__vmalloc_area_node(struct vm_struct *area, gfp_t gfp_mask, + pgprot_t prot, unsigned int page_shift, + int node) +{ + const gfp_t nested_gfp = (gfp_mask & GFP_RECLAIM_MASK) | __GFP_ZERO; + bool nofail = gfp_mask & __GFP_NOFAIL; + unsigned long addr = (unsigned long)area->addr; + unsigned long size = get_vm_area_size(area); + unsigned long array_size; + unsigned int nr_small_pages = size >> PAGE_SHIFT; + unsigned int page_order; + unsigned int flags; + int ret; + + array_size = (unsigned long)nr_small_pages * sizeof(struct page *); + + if (!(gfp_mask & (GFP_DMA | GFP_DMA32))) + gfp_mask |= __GFP_HIGHMEM; + + /* Please note that the recursion is strictly bounded. */ + if (array_size > PAGE_SIZE) { + area->pages = __vmalloc_node(array_size, 1, nested_gfp, node, + area->caller); + } else { + area->pages = kmalloc_node(array_size, nested_gfp, node); + } + + if (!area->pages) { + warn_alloc(gfp_mask, NULL, + "vmalloc error: size %lu, failed to allocated page array size %lu", + nr_small_pages * PAGE_SIZE, array_size); + free_vm_area(area); + return NULL; + } + + set_vm_area_page_order(area, page_shift - PAGE_SHIFT); + page_order = vm_area_page_order(area); + + area->nr_pages = vm_area_alloc_pages(gfp_mask | __GFP_NOWARN, + node, page_order, nr_small_pages, area->pages); + + atomic_long_add(area->nr_pages, &nr_vmalloc_pages); + if (gfp_mask & __GFP_ACCOUNT) { + int i; + + for (i = 0; i < area->nr_pages; i++) + mod_memcg_page_state(area->pages[i], MEMCG_VMALLOC, 1); + } + + /* + * If not enough pages were obtained to accomplish an + * allocation request, free them via vfree() if any. + */ + if (area->nr_pages != nr_small_pages) { + /* + * vm_area_alloc_pages() can fail due to insufficient memory but + * also:- + * + * - a pending fatal signal + * - insufficient huge page-order pages + * + * Since we always retry allocations at order-0 in the huge page + * case a warning for either is spurious. + */ + if (!fatal_signal_pending(current) && page_order == 0) + warn_alloc(gfp_mask, NULL, + "vmalloc error: size %lu, failed to allocate pages", + area->nr_pages * PAGE_SIZE); + goto fail; + } + + /* + * page tables allocations ignore external gfp mask, enforce it + * by the scope API + */ + if ((gfp_mask & (__GFP_FS | __GFP_IO)) == __GFP_IO) + flags = memalloc_nofs_save(); + else if ((gfp_mask & (__GFP_FS | __GFP_IO)) == 0) + flags = memalloc_noio_save(); + + do { + ret = vmap_pages_range(addr, addr + size, prot, area->pages, + page_shift); + if (nofail && (ret < 0)) + schedule_timeout_uninterruptible(1); + } while (nofail && (ret < 0)); + + if ((gfp_mask & (__GFP_FS | __GFP_IO)) == __GFP_IO) + memalloc_nofs_restore(flags); + else if ((gfp_mask & (__GFP_FS | __GFP_IO)) == 0) + memalloc_noio_restore(flags); + + if (ret < 0) { + warn_alloc(gfp_mask, NULL, + "vmalloc error: size %lu, failed to map pages", + area->nr_pages * PAGE_SIZE); + goto fail; + } + + return area->addr; + +fail: + 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. Please note that the full set of gfp + * flags are not supported. GFP_KERNEL, GFP_NOFS and GFP_NOIO are all + * supported. + * Zone modifiers are not supported. From the reclaim modifiers + * __GFP_DIRECT_RECLAIM is required (aka GFP_NOWAIT is not supported) + * and only __GFP_NOFAIL is supported (i.e. __GFP_NORETRY and + * __GFP_RETRY_MAYFAIL are not supported). + * + * __GFP_NOWARN can be used to suppress failures messages. + * + * 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 *ret; + kasan_vmalloc_flags_t kasan_flags = KASAN_VMALLOC_NONE; + unsigned long real_size = size; + unsigned long real_align = align; + unsigned int shift = PAGE_SHIFT; + + if (WARN_ON_ONCE(!size)) + return NULL; + + if ((size >> PAGE_SHIFT) > totalram_pages()) { + warn_alloc(gfp_mask, NULL, + "vmalloc error: size %lu, exceeds total pages", + real_size); + return NULL; + } + + if (vmap_allow_huge && (vm_flags & VM_ALLOW_HUGE_VMAP)) { + unsigned long size_per_node; + + /* + * Try huge pages. Only try for PAGE_KERNEL allocations, + * others like modules don't yet expect huge pages in + * their allocations due to apply_to_page_range not + * supporting them. + */ + + size_per_node = size; + if (node == NUMA_NO_NODE) + size_per_node /= num_online_nodes(); + if (arch_vmap_pmd_supported(prot) && size_per_node >= PMD_SIZE) + shift = PMD_SHIFT; + else + shift = arch_vmap_pte_supported_shift(size_per_node); + + align = max(real_align, 1UL << shift); + size = ALIGN(real_size, 1UL << shift); + } + +again: + area = __get_vm_area_node(real_size, align, shift, VM_ALLOC | + VM_UNINITIALIZED | vm_flags, start, end, node, + gfp_mask, caller); + if (!area) { + bool nofail = gfp_mask & __GFP_NOFAIL; + warn_alloc(gfp_mask, NULL, + "vmalloc error: size %lu, vm_struct allocation failed%s", + real_size, (nofail) ? ". Retrying." : ""); + if (nofail) { + schedule_timeout_uninterruptible(1); + goto again; + } + goto fail; + } + + /* + * Prepare arguments for __vmalloc_area_node() and + * kasan_unpoison_vmalloc(). + */ + if (pgprot_val(prot) == pgprot_val(PAGE_KERNEL)) { + if (kasan_hw_tags_enabled()) { + /* + * Modify protection bits to allow tagging. + * This must be done before mapping. + */ + prot = arch_vmap_pgprot_tagged(prot); + + /* + * Skip page_alloc poisoning and zeroing for physical + * pages backing VM_ALLOC mapping. Memory is instead + * poisoned and zeroed by kasan_unpoison_vmalloc(). + */ + gfp_mask |= __GFP_SKIP_KASAN | __GFP_SKIP_ZERO; + } + + /* Take note that the mapping is PAGE_KERNEL. */ + kasan_flags |= KASAN_VMALLOC_PROT_NORMAL; + } + + /* Allocate physical pages and map them into vmalloc space. */ + ret = __vmalloc_area_node(area, gfp_mask, prot, shift, node); + if (!ret) + goto fail; + + /* + * Mark the pages as accessible, now that they are mapped. + * The condition for setting KASAN_VMALLOC_INIT should complement the + * one in post_alloc_hook() with regards to the __GFP_SKIP_ZERO check + * to make sure that memory is initialized under the same conditions. + * Tag-based KASAN modes only assign tags to normal non-executable + * allocations, see __kasan_unpoison_vmalloc(). + */ + kasan_flags |= KASAN_VMALLOC_VM_ALLOC; + if (!want_init_on_free() && want_init_on_alloc(gfp_mask) && + (gfp_mask & __GFP_SKIP_ZERO)) + kasan_flags |= KASAN_VMALLOC_INIT; + /* KASAN_VMALLOC_PROT_NORMAL already set if required. */ + area->addr = kasan_unpoison_vmalloc(area->addr, real_size, kasan_flags); + + /* + * 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); + + size = PAGE_ALIGN(size); + if (!(vm_flags & VM_DEFER_KMEMLEAK)) + kmemleak_vmalloc(area, size, gfp_mask); + + return area->addr; + +fail: + if (shift > PAGE_SHIFT) { + shift = PAGE_SHIFT; + align = real_align; + size = real_size; + goto again; + } + + 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); + +/** + * vmalloc_huge - allocate virtually contiguous memory, allow huge pages + * @size: allocation size + * @gfp_mask: flags for the page level allocator + * + * Allocate enough pages to cover @size from the page level + * allocator and map them into contiguous kernel virtual space. + * If @size is greater than or equal to PMD_SIZE, allow using + * huge pages for the memory + * + * Return: pointer to the allocated memory or %NULL on error + */ +void *vmalloc_huge(unsigned long size, gfp_t gfp_mask) +{ + return __vmalloc_node_range(size, 1, VMALLOC_START, VMALLOC_END, + gfp_mask, PAGE_KERNEL, VM_ALLOW_HUGE_VMAP, + NUMA_NO_NODE, __builtin_return_address(0)); +} +EXPORT_SYMBOL_GPL(vmalloc_huge); + +/** + * vzalloc - allocate virtually contiguous memory with zero fill + * @size: allocation size + * + * Allocate enough pages to cover @size from the page level + * allocator and map them into contiguous kernel virtual space. + * The memory allocated is set to zero. + * + * For tight control over page level allocator and protection flags + * use __vmalloc() instead. + * + * Return: pointer to the allocated memory or %NULL on error + */ +void *vzalloc(unsigned long size) +{ + return __vmalloc_node(size, 1, GFP_KERNEL | __GFP_ZERO, NUMA_NO_NODE, + __builtin_return_address(0)); +} +EXPORT_SYMBOL(vzalloc); + +/** + * vmalloc_user - allocate zeroed virtually contiguous memory for userspace + * @size: allocation size + * + * The resulting memory area is zeroed so it can be mapped to userspace + * without leaking data. + * + * Return: pointer to the allocated memory or %NULL on error + */ +void *vmalloc_user(unsigned long size) +{ + return __vmalloc_node_range(size, SHMLBA, VMALLOC_START, VMALLOC_END, + GFP_KERNEL | __GFP_ZERO, PAGE_KERNEL, + VM_USERMAP, NUMA_NO_NODE, + __builtin_return_address(0)); +} +EXPORT_SYMBOL(vmalloc_user); + +/** + * vmalloc_node - allocate memory on a specific node + * @size: allocation size + * @node: numa node + * + * Allocate enough pages to cover @size from the page level + * allocator and map them into contiguous kernel virtual space. + * + * For tight control over page level allocator and protection flags + * use __vmalloc() instead. + * + * Return: pointer to the allocated memory or %NULL on error + */ +void *vmalloc_node(unsigned long size, int node) +{ + return __vmalloc_node(size, 1, GFP_KERNEL, node, + __builtin_return_address(0)); +} +EXPORT_SYMBOL(vmalloc_node); + +/** + * vzalloc_node - allocate memory on a specific node with zero fill + * @size: allocation size + * @node: numa node + * + * Allocate enough pages to cover @size from the page level + * allocator and map them into contiguous kernel virtual space. + * The memory allocated is set to zero. + * + * Return: pointer to the allocated memory or %NULL on error + */ +void *vzalloc_node(unsigned long size, int node) +{ + return __vmalloc_node(size, 1, GFP_KERNEL | __GFP_ZERO, node, + __builtin_return_address(0)); +} +EXPORT_SYMBOL(vzalloc_node); + +#if defined(CONFIG_64BIT) && defined(CONFIG_ZONE_DMA32) +#define GFP_VMALLOC32 (GFP_DMA32 | GFP_KERNEL) +#elif defined(CONFIG_64BIT) && defined(CONFIG_ZONE_DMA) +#define GFP_VMALLOC32 (GFP_DMA | GFP_KERNEL) +#else +/* + * 64b systems should always have either DMA or DMA32 zones. For others + * GFP_DMA32 should do the right thing and use the normal zone. + */ +#define GFP_VMALLOC32 (GFP_DMA32 | GFP_KERNEL) +#endif + +/** + * vmalloc_32 - allocate virtually contiguous memory (32bit addressable) + * @size: allocation size + * + * Allocate enough 32bit PA addressable pages to cover @size from the + * page level allocator and map them into contiguous kernel virtual space. + * + * Return: pointer to the allocated memory or %NULL on error + */ +void *vmalloc_32(unsigned long size) +{ + return __vmalloc_node(size, 1, GFP_VMALLOC32, NUMA_NO_NODE, + __builtin_return_address(0)); +} +EXPORT_SYMBOL(vmalloc_32); + +/** + * vmalloc_32_user - allocate zeroed virtually contiguous 32bit memory + * @size: allocation size + * + * The resulting memory area is 32bit addressable and zeroed so it can be + * mapped to userspace without leaking data. + * + * Return: pointer to the allocated memory or %NULL on error + */ +void *vmalloc_32_user(unsigned long size) +{ + return __vmalloc_node_range(size, SHMLBA, VMALLOC_START, VMALLOC_END, + GFP_VMALLOC32 | __GFP_ZERO, PAGE_KERNEL, + VM_USERMAP, NUMA_NO_NODE, + __builtin_return_address(0)); +} +EXPORT_SYMBOL(vmalloc_32_user); + +/* + * Atomically zero bytes in the iterator. + * + * Returns the number of zeroed bytes. + */ +static size_t zero_iter(struct iov_iter *iter, size_t count) +{ + size_t remains = count; + + while (remains > 0) { + size_t num, copied; + + num = min_t(size_t, remains, PAGE_SIZE); + copied = copy_page_to_iter_nofault(ZERO_PAGE(0), 0, num, iter); + remains -= copied; + + if (copied < num) + break; + } + + return count - remains; +} + +/* + * small helper routine, copy contents to iter from addr. + * If the page is not present, fill zero. + * + * Returns the number of copied bytes. + */ +static size_t aligned_vread_iter(struct iov_iter *iter, + const char *addr, size_t count) +{ + size_t remains = count; + struct page *page; + + while (remains > 0) { + unsigned long offset, length; + size_t copied = 0; + + offset = offset_in_page(addr); + length = PAGE_SIZE - offset; + if (length > remains) + length = remains; + page = 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() calls for this _debug_ interface, rarely + * used. Instead of that, we'll use an local mapping via + * copy_page_to_iter_nofault() and accept a small overhead in + * this access function. + */ + if (page) + copied = copy_page_to_iter_nofault(page, offset, + length, iter); + else + copied = zero_iter(iter, length); + + addr += copied; + remains -= copied; + + if (copied != length) + break; + } + + return count - remains; +} + +/* + * Read from a vm_map_ram region of memory. + * + * Returns the number of copied bytes. + */ +static size_t vmap_ram_vread_iter(struct iov_iter *iter, const char *addr, + size_t count, unsigned long flags) +{ + char *start; + struct vmap_block *vb; + struct xarray *xa; + unsigned long offset; + unsigned int rs, re; + size_t remains, n; + + /* + * If it's area created by vm_map_ram() interface directly, but + * not further subdividing and delegating management to vmap_block, + * handle it here. + */ + if (!(flags & VMAP_BLOCK)) + return aligned_vread_iter(iter, addr, count); + + remains = count; + + /* + * Area is split into regions and tracked with vmap_block, read out + * each region and zero fill the hole between regions. + */ + xa = addr_to_vb_xa((unsigned long) addr); + vb = xa_load(xa, addr_to_vb_idx((unsigned long)addr)); + if (!vb) + goto finished_zero; + + spin_lock(&vb->lock); + if (bitmap_empty(vb->used_map, VMAP_BBMAP_BITS)) { + spin_unlock(&vb->lock); + goto finished_zero; + } + + for_each_set_bitrange(rs, re, vb->used_map, VMAP_BBMAP_BITS) { + size_t copied; + + if (remains == 0) + goto finished; + + start = vmap_block_vaddr(vb->va->va_start, rs); + + if (addr < start) { + size_t to_zero = min_t(size_t, start - addr, remains); + size_t zeroed = zero_iter(iter, to_zero); + + addr += zeroed; + remains -= zeroed; + + if (remains == 0 || zeroed != to_zero) + goto finished; + } + + /*it could start reading from the middle of used region*/ + offset = offset_in_page(addr); + n = ((re - rs + 1) << PAGE_SHIFT) - offset; + if (n > remains) + n = remains; + + copied = aligned_vread_iter(iter, start + offset, n); + + addr += copied; + remains -= copied; + + if (copied != n) + goto finished; + } + + spin_unlock(&vb->lock); + +finished_zero: + /* zero-fill the left dirty or free regions */ + return count - remains + zero_iter(iter, remains); +finished: + /* We couldn't copy/zero everything */ + spin_unlock(&vb->lock); + return count - remains; +} + +/** + * vread_iter() - read vmalloc area in a safe way to an iterator. + * @iter: the iterator to which data should be written. + * @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 /proc/kcore. + * + * 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_iter(struct iov_iter *iter, const char *addr, size_t count) +{ + struct vmap_area *va; + struct vm_struct *vm; + char *vaddr; + size_t n, size, flags, remains; + + addr = kasan_reset_tag(addr); + + /* Don't allow overflow */ + if ((unsigned long) addr + count < count) + count = -(unsigned long) addr; + + remains = count; + + spin_lock(&vmap_area_lock); + va = find_vmap_area_exceed_addr((unsigned long)addr); + if (!va) + goto finished_zero; + + /* no intersects with alive vmap_area */ + if ((unsigned long)addr + remains <= va->va_start) + goto finished_zero; + + list_for_each_entry_from(va, &vmap_area_list, list) { + size_t copied; + + if (remains == 0) + goto finished; + + vm = va->vm; + flags = va->flags & VMAP_FLAGS_MASK; + /* + * VMAP_BLOCK indicates a sub-type of vm_map_ram area, need + * be set together with VMAP_RAM. + */ + WARN_ON(flags == VMAP_BLOCK); + + if (!vm && !flags) + continue; + + if (vm && (vm->flags & VM_UNINITIALIZED)) + continue; + + /* Pair with smp_wmb() in clear_vm_uninitialized_flag() */ + smp_rmb(); + + vaddr = (char *) va->va_start; + size = vm ? get_vm_area_size(vm) : va_size(va); + + if (addr >= vaddr + size) + continue; + + if (addr < vaddr) { + size_t to_zero = min_t(size_t, vaddr - addr, remains); + size_t zeroed = zero_iter(iter, to_zero); + + addr += zeroed; + remains -= zeroed; + + if (remains == 0 || zeroed != to_zero) + goto finished; + } + + n = vaddr + size - addr; + if (n > remains) + n = remains; + + if (flags & VMAP_RAM) + copied = vmap_ram_vread_iter(iter, addr, n, flags); + else if (!(vm->flags & VM_IOREMAP)) + copied = aligned_vread_iter(iter, addr, n); + else /* IOREMAP area is treated as memory hole */ + copied = zero_iter(iter, n); + + addr += copied; + remains -= copied; + + if (copied != n) + goto finished; + } + +finished_zero: + spin_unlock(&vmap_area_lock); + /* zero-fill memory holes */ + return count - remains + zero_iter(iter, remains); +finished: + /* Nothing remains, or We couldn't copy/zero everything. */ + spin_unlock(&vmap_area_lock); + + return count - remains; +} + +/** + * 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); + + vm_flags_set(vma, VM_DONTEXPAND | VM_DONTDUMP); + + return 0; +} + +/** + * remap_vmalloc_range - map vmalloc pages to userspace + * @vma: vma to cover (map full range of vma) + * @addr: vmalloc memory + * @pgoff: number of pages into addr before first page to map + * + * Returns: 0 for success, -Exxx on failure + * + * This function checks that addr is a valid vmalloc'ed area, and + * that it is big enough to cover the vma. Will return failure if + * that criteria isn't met. + * + * Similar to remap_pfn_range() (see mm/memory.c) + */ +int remap_vmalloc_range(struct vm_area_struct *vma, void *addr, + unsigned long pgoff) +{ + return remap_vmalloc_range_partial(vma, vma->vm_start, + addr, pgoff, + vma->vm_end - vma->vm_start); +} +EXPORT_SYMBOL(remap_vmalloc_range); + +void free_vm_area(struct vm_struct *area) +{ + struct vm_struct *ret; + ret = remove_vm_area(area->addr); + BUG_ON(ret != area); + kfree(area); +} +EXPORT_SYMBOL_GPL(free_vm_area); + +#ifdef CONFIG_SMP +static struct vmap_area *node_to_va(struct rb_node *n) +{ + return rb_entry_safe(n, struct vmap_area, rb_node); +} + +/** + * pvm_find_va_enclose_addr - find the vmap_area @addr belongs to + * @addr: target address + * + * Returns: vmap_area if it is found. If there is no such area + * the first highest(reverse order) vmap_area is returned + * i.e. va->va_start < addr && va->va_end < addr or NULL + * if there are no any areas before @addr. + */ +static struct vmap_area * +pvm_find_va_enclose_addr(unsigned long addr) +{ + struct vmap_area *va, *tmp; + struct rb_node *n; + + n = free_vmap_area_root.rb_node; + va = NULL; + + while (n) { + tmp = rb_entry(n, struct vmap_area, rb_node); + if (tmp->va_start <= addr) { + va = tmp; + if (tmp->va_end >= addr) + break; + + n = n->rb_right; + } else { + n = n->rb_left; + } + } + + return va; +} + +/** + * pvm_determine_end_from_reverse - find the highest aligned address + * of free block below VMALLOC_END + * @va: + * in - the VA we start the search(reverse order); + * out - the VA with the highest aligned end address. + * @align: alignment for required highest 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; + + /* verify parameters and allocate data structures */ + BUG_ON(offset_in_page(align) || !is_power_of_2(align)); + for (last_area = 0, area = 0; area < nr_vms; area++) { + start = offsets[area]; + end = start + sizes[area]; + + /* is everything aligned properly? */ + BUG_ON(!IS_ALIGNED(offsets[area], align)); + BUG_ON(!IS_ALIGNED(sizes[area], align)); + + /* detect the area with the highest address */ + if (start > offsets[last_area]) + last_area = area; + + for (area2 = area + 1; area2 < nr_vms; area2++) { + unsigned long start2 = offsets[area2]; + unsigned long end2 = start2 + sizes[area2]; + + BUG_ON(start2 < end && start < end2); + } + } + last_end = offsets[last_area] + sizes[last_area]; + + if (vmalloc_end - vmalloc_start < last_end) { + WARN_ON(true); + return NULL; + } + + vms = kcalloc(nr_vms, sizeof(vms[0]), GFP_KERNEL); + vas = kcalloc(nr_vms, sizeof(vas[0]), GFP_KERNEL); + if (!vas || !vms) + goto err_free2; + + for (area = 0; area < nr_vms; area++) { + vas[area] = kmem_cache_zalloc(vmap_area_cachep, GFP_KERNEL); + vms[area] = kzalloc(sizeof(struct vm_struct), GFP_KERNEL); + if (!vas[area] || !vms[area]) + goto err_free; + } +retry: + spin_lock(&free_vmap_area_lock); + + /* start scanning - we scan from the top, begin with the last area */ + area = term_area = last_area; + start = offsets[area]; + end = start + sizes[area]; + + va = pvm_find_va_enclose_addr(vmalloc_end); + base = pvm_determine_end_from_reverse(&va, align) - end; + + while (true) { + /* + * base might have underflowed, add last_end before + * comparing. + */ + if (base + last_end < vmalloc_start + last_end) + goto overflow; + + /* + * Fitting base has not been found. + */ + if (va == NULL) + goto overflow; + + /* + * If required width exceeds current VA block, move + * base downwards and then recheck. + */ + if (base + end > va->va_end) { + base = pvm_determine_end_from_reverse(&va, align) - end; + term_area = area; + continue; + } + + /* + * If this VA does not fit, move base downwards and recheck. + */ + if (base + start < va->va_start) { + va = node_to_va(rb_prev(&va->rb_node)); + base = pvm_determine_end_from_reverse(&va, align) - end; + term_area = area; + continue; + } + + /* + * This area fits, move on to the previous one. If + * the previous one is the terminal one, we're done. + */ + area = (area + nr_vms - 1) % nr_vms; + if (area == term_area) + break; + + start = offsets[area]; + end = start + sizes[area]; + va = pvm_find_va_enclose_addr(base + end); + } + + /* we've found a fitting base, insert all va's */ + for (area = 0; area < nr_vms; area++) { + int ret; + + start = base + offsets[area]; + size = sizes[area]; + + va = pvm_find_va_enclose_addr(start); + if (WARN_ON_ONCE(va == NULL)) + /* It is a BUG(), but trigger recovery instead. */ + goto recovery; + + ret = adjust_va_to_fit_type(&free_vmap_area_root, + &free_vmap_area_list, + va, start, size); + if (WARN_ON_ONCE(unlikely(ret))) + /* It is a BUG(), but trigger recovery instead. */ + goto recovery; + + /* Allocated area. */ + va = vas[area]; + va->va_start = start; + va->va_end = start + size; + } + + spin_unlock(&free_vmap_area_lock); + + /* populate the kasan shadow space */ + for (area = 0; area < nr_vms; area++) { + if (kasan_populate_vmalloc(vas[area]->va_start, sizes[area])) + goto err_free_shadow; + } + + /* insert all vm's */ + spin_lock(&vmap_area_lock); + for (area = 0; area < nr_vms; area++) { + insert_vmap_area(vas[area], &vmap_area_root, &vmap_area_list); + + setup_vmalloc_vm_locked(vms[area], vas[area], VM_ALLOC, + pcpu_get_vm_areas); + } + spin_unlock(&vmap_area_lock); + + /* + * Mark allocated areas as accessible. Do it now as a best-effort + * approach, as they can be mapped outside of vmalloc code. + * With hardware tag-based KASAN, marking is skipped for + * non-VM_ALLOC mappings, see __kasan_unpoison_vmalloc(). + */ + for (area = 0; area < nr_vms; area++) + vms[area]->addr = kasan_unpoison_vmalloc(vms[area]->addr, + vms[area]->size, KASAN_VMALLOC_PROT_NORMAL); + + kfree(vas); + return vms; + +recovery: + /* + * Remove previously allocated areas. There is no + * need in removing these areas from the busy tree, + * because they are inserted only on the final step + * and when pcpu_get_vm_areas() is success. + */ + while (area--) { + orig_start = vas[area]->va_start; + orig_end = vas[area]->va_end; + va = merge_or_add_vmap_area_augment(vas[area], &free_vmap_area_root, + &free_vmap_area_list); + if (va) + kasan_release_vmalloc(orig_start, orig_end, + va->va_start, va->va_end); + vas[area] = NULL; + } + +overflow: + spin_unlock(&free_vmap_area_lock); + if (!purged) { + reclaim_and_purge_vmap_areas(); + purged = true; + + /* Before "retry", check if we recover. */ + for (area = 0; area < nr_vms; area++) { + if (vas[area]) + continue; + + vas[area] = kmem_cache_zalloc( + vmap_area_cachep, GFP_KERNEL); + if (!vas[area]) + goto err_free; + } + + goto retry; + } + +err_free: + for (area = 0; area < nr_vms; area++) { + if (vas[area]) + kmem_cache_free(vmap_area_cachep, vas[area]); + + kfree(vms[area]); + } +err_free2: + kfree(vas); + kfree(vms); + return NULL; + +err_free_shadow: + spin_lock(&free_vmap_area_lock); + /* + * We release all the vmalloc shadows, even the ones for regions that + * hadn't been successfully added. This relies on kasan_release_vmalloc + * being able to tolerate this case. + */ + for (area = 0; area < nr_vms; area++) { + orig_start = vas[area]->va_start; + orig_end = vas[area]->va_end; + va = merge_or_add_vmap_area_augment(vas[area], &free_vmap_area_root, + &free_vmap_area_list); + if (va) + kasan_release_vmalloc(orig_start, orig_end, + va->va_start, va->va_end); + vas[area] = NULL; + kfree(vms[area]); + } + spin_unlock(&free_vmap_area_lock); + kfree(vas); + kfree(vms); + return NULL; +} + +/** + * pcpu_free_vm_areas - free vmalloc areas for percpu allocator + * @vms: vm_struct pointer array returned by pcpu_get_vm_areas() + * @nr_vms: the number of allocated areas + * + * Free vm_structs and the array allocated by pcpu_get_vm_areas(). + */ +void pcpu_free_vm_areas(struct vm_struct **vms, int nr_vms) +{ + int i; + + for (i = 0; i < nr_vms; i++) + free_vm_area(vms[i]); + kfree(vms); +} +#endif /* CONFIG_SMP */ + +#ifdef CONFIG_PRINTK +bool vmalloc_dump_obj(void *object) +{ + void *objp = (void *)PAGE_ALIGN((unsigned long)object); + const void *caller; + struct vm_struct *vm; + struct vmap_area *va; + unsigned long addr; + unsigned int nr_pages; + + if (!spin_trylock(&vmap_area_lock)) + return false; + va = __find_vmap_area((unsigned long)objp, &vmap_area_root); + if (!va) { + spin_unlock(&vmap_area_lock); + return false; + } + + vm = va->vm; + if (!vm) { + spin_unlock(&vmap_area_lock); + return false; + } + addr = (unsigned long)vm->addr; + caller = vm->caller; + nr_pages = vm->nr_pages; + spin_unlock(&vmap_area_lock); + pr_cont(" %u-page vmalloc region starting at %#lx allocated at %pS\n", + nr_pages, addr, caller); + return true; +} +#endif + +#ifdef CONFIG_PROC_FS +static void *s_start(struct seq_file *m, loff_t *pos) + __acquires(&vmap_purge_lock) + __acquires(&vmap_area_lock) +{ + mutex_lock(&vmap_purge_lock); + spin_lock(&vmap_area_lock); + + return seq_list_start(&vmap_area_list, *pos); +} + +static void *s_next(struct seq_file *m, void *p, loff_t *pos) +{ + return seq_list_next(p, &vmap_area_list, pos); +} + +static void s_stop(struct seq_file *m, void *p) + __releases(&vmap_area_lock) + __releases(&vmap_purge_lock) +{ + spin_unlock(&vmap_area_lock); + mutex_unlock(&vmap_purge_lock); +} + +static void show_numa_info(struct seq_file *m, struct vm_struct *v) +{ + if (IS_ENABLED(CONFIG_NUMA)) { + unsigned int nr, *counters = m->private; + unsigned int step = 1U << vm_area_page_order(v); + + 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 += step) + counters[page_to_nid(v->pages[nr])] += step; + for_each_node_state(nr, N_HIGH_MEMORY) + if (counters[nr]) + seq_printf(m, " N%u=%u", nr, counters[nr]); + } +} + +static void show_purge_info(struct seq_file *m) +{ + struct vmap_area *va; + + spin_lock(&purge_vmap_area_lock); + list_for_each_entry(va, &purge_vmap_area_list, list) { + seq_printf(m, "0x%pK-0x%pK %7ld unpurged vm_area\n", + (void *)va->va_start, (void *)va->va_end, + va->va_end - va->va_start); + } + spin_unlock(&purge_vmap_area_lock); +} + +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); + + if (!va->vm) { + if (va->flags & VMAP_RAM) + seq_printf(m, "0x%pK-0x%pK %7ld vm_map_ram\n", + (void *)va->va_start, (void *)va->va_end, + va->va_end - va->va_start); + + goto final; + } + + v = va->vm; + + seq_printf(m, "0x%pK-0x%pK %7ld", + v->addr, v->addr + v->size, v->size); + + if (v->caller) + seq_printf(m, " %pS", v->caller); + + if (v->nr_pages) + seq_printf(m, " pages=%d", v->nr_pages); + + if (v->phys_addr) + seq_printf(m, " phys=%pa", &v->phys_addr); + + if (v->flags & VM_IOREMAP) + seq_puts(m, " ioremap"); + + if (v->flags & VM_ALLOC) + seq_puts(m, " vmalloc"); + + if (v->flags & VM_MAP) + seq_puts(m, " vmap"); + + if (v->flags & VM_USERMAP) + seq_puts(m, " user"); + + if (v->flags & VM_DMA_COHERENT) + seq_puts(m, " dma-coherent"); + + if (is_vmalloc_addr(v->pages)) + seq_puts(m, " vpages"); + + show_numa_info(m, v); + seq_putc(m, '\n'); + + /* + * As a final step, dump "unpurged" areas. + */ +final: + if (list_is_last(&va->list, &vmap_area_list)) + show_purge_info(m); + + return 0; +} + +static const struct seq_operations vmalloc_op = { + .start = s_start, + .next = s_next, + .stop = s_stop, + .show = s_show, +}; + +static int __init proc_vmalloc_init(void) +{ + if (IS_ENABLED(CONFIG_NUMA)) + proc_create_seq_private("vmallocinfo", 0400, NULL, + &vmalloc_op, + nr_node_ids * sizeof(unsigned int), NULL); + else + proc_create_seq("vmallocinfo", 0400, NULL, &vmalloc_op); + return 0; +} +module_init(proc_vmalloc_init); + +#endif + +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, delayed_vfree_work); + xa_init(&vbq->vmap_blocks); + } + + /* 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; +} |