| // 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> |
| #include <linux/page_owner.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; |
| struct page *page; |
| unsigned long size = PAGE_SIZE; |
| |
| pfn = phys_addr >> PAGE_SHIFT; |
| pte = pte_alloc_kernel_track(pmd, addr, mask); |
| if (!pte) |
| return -ENOMEM; |
| do { |
| if (!pte_none(ptep_get(pte))) { |
| if (pfn_valid(pfn)) { |
| page = pfn_to_page(pfn); |
| dump_page(page, "remapping already mapped page"); |
| } |
| BUG(); |
| } |
| |
| #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 vmap_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; |
| } |
| |
| int ioremap_page_range(unsigned long addr, unsigned long end, |
| phys_addr_t phys_addr, pgprot_t prot) |
| { |
| struct vm_struct *area; |
| |
| area = find_vm_area((void *)addr); |
| if (!area || !(area->flags & VM_IOREMAP)) { |
| WARN_ONCE(1, "vm_area at addr %lx is not marked as VM_IOREMAP\n", addr); |
| return -EINVAL; |
| } |
| if (addr != (unsigned long)area->addr || |
| (void *)end != area->addr + get_vm_area_size(area)) { |
| WARN_ONCE(1, "ioremap request [%lx,%lx) doesn't match vm_area [%lx, %lx)\n", |
| addr, end, (long)area->addr, |
| (long)area->addr + get_vm_area_size(area)); |
| return -ERANGE; |
| } |
| return vmap_page_range(addr, end, phys_addr, prot); |
| } |
| |
| 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; |
| } |
| |
| static int check_sparse_vm_area(struct vm_struct *area, unsigned long start, |
| unsigned long end) |
| { |
| might_sleep(); |
| if (WARN_ON_ONCE(area->flags & VM_FLUSH_RESET_PERMS)) |
| return -EINVAL; |
| if (WARN_ON_ONCE(area->flags & VM_NO_GUARD)) |
| return -EINVAL; |
| if (WARN_ON_ONCE(!(area->flags & VM_SPARSE))) |
| return -EINVAL; |
| if ((end - start) >> PAGE_SHIFT > totalram_pages()) |
| return -E2BIG; |
| if (start < (unsigned long)area->addr || |
| (void *)end > area->addr + get_vm_area_size(area)) |
| return -ERANGE; |
| return 0; |
| } |
| |
| /** |
| * vm_area_map_pages - map pages inside given sparse vm_area |
| * @area: vm_area |
| * @start: start address inside vm_area |
| * @end: end address inside vm_area |
| * @pages: pages to map (always PAGE_SIZE pages) |
| */ |
| int vm_area_map_pages(struct vm_struct *area, unsigned long start, |
| unsigned long end, struct page **pages) |
| { |
| int err; |
| |
| err = check_sparse_vm_area(area, start, end); |
| if (err) |
| return err; |
| |
| return vmap_pages_range(start, end, PAGE_KERNEL, pages, PAGE_SHIFT); |
| } |
| |
| /** |
| * vm_area_unmap_pages - unmap pages inside given sparse vm_area |
| * @area: vm_area |
| * @start: start address inside vm_area |
| * @end: end address inside vm_area |
| */ |
| void vm_area_unmap_pages(struct vm_struct *area, unsigned long start, |
| unsigned long end) |
| { |
| if (check_sparse_vm_area(area, start, end)) |
| return; |
| |
| vunmap_range(start, end); |
| } |
| |
| 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_EXECMEM) && 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(free_vmap_area_lock); |
| static bool vmap_initialized __read_mostly; |
| |
| /* |
| * This kmem_cache is used for vmap_area objects. Instead of |
| * allocating from slab we reuse an object from this cache to |
| * make things faster. Especially in "no edge" splitting of |
| * free block. |
| */ |
| static struct kmem_cache *vmap_area_cachep; |
| |
| /* |
| * This linked list is used in pair with free_vmap_area_root. |
| * It gives O(1) access to prev/next to perform fast coalescing. |
| */ |
| static LIST_HEAD(free_vmap_area_list); |
| |
| /* |
| * This augment red-black tree represents the free vmap space. |
| * All vmap_area objects in this tree are sorted by va->va_start |
| * address. It is used for allocation and merging when a vmap |
| * object is released. |
| * |
| * Each vmap_area node contains a maximum available free block |
| * of its sub-tree, right or left. Therefore it is possible to |
| * find a lowest match of free area. |
| */ |
| static struct rb_root free_vmap_area_root = RB_ROOT; |
| |
| /* |
| * Preload a CPU with one object for "no edge" split case. The |
| * aim is to get rid of allocations from the atomic context, thus |
| * to use more permissive allocation masks. |
| */ |
| static DEFINE_PER_CPU(struct vmap_area *, ne_fit_preload_node); |
| |
| /* |
| * This structure defines a single, solid model where a list and |
| * rb-tree are part of one entity protected by the lock. Nodes are |
| * sorted in ascending order, thus for O(1) access to left/right |
| * neighbors a list is used as well as for sequential traversal. |
| */ |
| struct rb_list { |
| struct rb_root root; |
| struct list_head head; |
| spinlock_t lock; |
| }; |
| |
| /* |
| * A fast size storage contains VAs up to 1M size. A pool consists |
| * of linked between each other ready to go VAs of certain sizes. |
| * An index in the pool-array corresponds to number of pages + 1. |
| */ |
| #define MAX_VA_SIZE_PAGES 256 |
| |
| struct vmap_pool { |
| struct list_head head; |
| unsigned long len; |
| }; |
| |
| /* |
| * An effective vmap-node logic. Users make use of nodes instead |
| * of a global heap. It allows to balance an access and mitigate |
| * contention. |
| */ |
| static struct vmap_node { |
| /* Simple size segregated storage. */ |
| struct vmap_pool pool[MAX_VA_SIZE_PAGES]; |
| spinlock_t pool_lock; |
| bool skip_populate; |
| |
| /* Bookkeeping data of this node. */ |
| struct rb_list busy; |
| struct rb_list lazy; |
| |
| /* |
| * Ready-to-free areas. |
| */ |
| struct list_head purge_list; |
| struct work_struct purge_work; |
| unsigned long nr_purged; |
| } single; |
| |
| /* |
| * Initial setup consists of one single node, i.e. a balancing |
| * is fully disabled. Later on, after vmap is initialized these |
| * parameters are updated based on a system capacity. |
| */ |
| static struct vmap_node *vmap_nodes = &single; |
| static __read_mostly unsigned int nr_vmap_nodes = 1; |
| static __read_mostly unsigned int vmap_zone_size = 1; |
| |
| static inline unsigned int |
| addr_to_node_id(unsigned long addr) |
| { |
| return (addr / vmap_zone_size) % nr_vmap_nodes; |
| } |
| |
| static inline struct vmap_node * |
| addr_to_node(unsigned long addr) |
| { |
| return &vmap_nodes[addr_to_node_id(addr)]; |
| } |
| |
| static inline struct vmap_node * |
| id_to_node(unsigned int id) |
| { |
| return &vmap_nodes[id % nr_vmap_nodes]; |
| } |
| |
| /* |
| * We use the value 0 to represent "no node", that is why |
| * an encoded value will be the node-id incremented by 1. |
| * It is always greater then 0. A valid node_id which can |
| * be encoded is [0:nr_vmap_nodes - 1]. If a passed node_id |
| * is not valid 0 is returned. |
| */ |
| static unsigned int |
| encode_vn_id(unsigned int node_id) |
| { |
| /* Can store U8_MAX [0:254] nodes. */ |
| if (node_id < nr_vmap_nodes) |
| return (node_id + 1) << BITS_PER_BYTE; |
| |
| /* Warn and no node encoded. */ |
| WARN_ONCE(1, "Encode wrong node id (%u)\n", node_id); |
| return 0; |
| } |
| |
| /* |
| * Returns an encoded node-id, the valid range is within |
| * [0:nr_vmap_nodes-1] values. Otherwise nr_vmap_nodes is |
| * returned if extracted data is wrong. |
| */ |
| static unsigned int |
| decode_vn_id(unsigned int val) |
| { |
| unsigned int node_id = (val >> BITS_PER_BYTE) - 1; |
| |
| /* Can store U8_MAX [0:254] nodes. */ |
| if (node_id < nr_vmap_nodes) |
| return node_id; |
| |
| /* If it was _not_ zero, warn. */ |
| WARN_ONCE(node_id != UINT_MAX, |
| "Decode wrong node id (%d)\n", node_id); |
| |
| return nr_vmap_nodes; |
| } |
| |
| static bool |
| is_vn_id_valid(unsigned int node_id) |
| { |
| if (node_id < nr_vmap_nodes) |
| return true; |
| |
| return false; |
| } |
| |
| 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); |
| } |
| |
| 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; |
| } |
| |
| /* 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 rb_root *root) |
| { |
| struct vmap_area *va = NULL; |
| struct rb_node *n = 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; |
| } |
| |
| /* |
| * Returns a node where a first VA, that satisfies addr < va_end, resides. |
| * If success, a node is locked. A user is responsible to unlock it when a |
| * VA is no longer needed to be accessed. |
| * |
| * Returns NULL if nothing found. |
| */ |
| static struct vmap_node * |
| find_vmap_area_exceed_addr_lock(unsigned long addr, struct vmap_area **va) |
| { |
| unsigned long va_start_lowest; |
| struct vmap_node *vn; |
| int i; |
| |
| repeat: |
| for (i = 0, va_start_lowest = 0; i < nr_vmap_nodes; i++) { |
| vn = &vmap_nodes[i]; |
| |
| spin_lock(&vn->busy.lock); |
| *va = __find_vmap_area_exceed_addr(addr, &vn->busy.root); |
| |
| if (*va) |
| if (!va_start_lowest || (*va)->va_start < va_start_lowest) |
| va_start_lowest = (*va)->va_start; |
| spin_unlock(&vn->busy.lock); |
| } |
| |
| /* |
| * Check if found VA exists, it might have gone away. In this case we |
| * repeat the search because a VA has been removed concurrently and we |
| * need to proceed to the next one, which is a rare case. |
| */ |
| if (va_start_lowest) { |
| vn = addr_to_node(va_start_lowest); |
| |
| spin_lock(&vn->busy.lock); |
| *va = __find_vmap_area(va_start_lowest, &vn->busy.root); |
| |
| if (*va) |
| return vn; |
| |
| spin_unlock(&vn->busy.lock); |
| goto repeat; |
| } |
| |
| 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 |
| va_clip(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; |
| } |
| |
| static unsigned long |
| va_alloc(struct vmap_area *va, |
| struct rb_root *root, struct list_head *head, |
| unsigned long size, unsigned long align, |
| unsigned long vstart, unsigned long vend) |
| { |
| unsigned long nva_start_addr; |
| int ret; |
| |
| 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 = va_clip(root, head, va, nva_start_addr, size); |
| if (WARN_ON_ONCE(ret)) |
| return vend; |
| |
| return nva_start_addr; |
| } |
| |
| /* |
| * 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; |
| |
| /* |
| * 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; |
| |
| nva_start_addr = va_alloc(va, root, head, size, align, vstart, vend); |
| if (nva_start_addr == vend) |
| 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) |
| { |
| struct vmap_node *vn = addr_to_node(va->va_start); |
| |
| /* |
| * Remove from the busy tree/list. |
| */ |
| spin_lock(&vn->busy.lock); |
| unlink_va(va, &vn->busy.root); |
| spin_unlock(&vn->busy.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, *tmp; |
| |
| /* |
| * 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); |
| |
| tmp = NULL; |
| if (va && !__this_cpu_try_cmpxchg(ne_fit_preload_node, &tmp, va)) |
| kmem_cache_free(vmap_area_cachep, va); |
| } |
| |
| static struct vmap_pool * |
| size_to_va_pool(struct vmap_node *vn, unsigned long size) |
| { |
| unsigned int idx = (size - 1) / PAGE_SIZE; |
| |
| if (idx < MAX_VA_SIZE_PAGES) |
| return &vn->pool[idx]; |
| |
| return NULL; |
| } |
| |
| static bool |
| node_pool_add_va(struct vmap_node *n, struct vmap_area *va) |
| { |
| struct vmap_pool *vp; |
| |
| vp = size_to_va_pool(n, va_size(va)); |
| if (!vp) |
| return false; |
| |
| spin_lock(&n->pool_lock); |
| list_add(&va->list, &vp->head); |
| WRITE_ONCE(vp->len, vp->len + 1); |
| spin_unlock(&n->pool_lock); |
| |
| return true; |
| } |
| |
| static struct vmap_area * |
| node_pool_del_va(struct vmap_node *vn, unsigned long size, |
| unsigned long align, unsigned long vstart, |
| unsigned long vend) |
| { |
| struct vmap_area *va = NULL; |
| struct vmap_pool *vp; |
| int err = 0; |
| |
| vp = size_to_va_pool(vn, size); |
| if (!vp || list_empty(&vp->head)) |
| return NULL; |
| |
| spin_lock(&vn->pool_lock); |
| if (!list_empty(&vp->head)) { |
| va = list_first_entry(&vp->head, struct vmap_area, list); |
| |
| if (IS_ALIGNED(va->va_start, align)) { |
| /* |
| * Do some sanity check and emit a warning |
| * if one of below checks detects an error. |
| */ |
| err |= (va_size(va) != size); |
| err |= (va->va_start < vstart); |
| err |= (va->va_end > vend); |
| |
| if (!WARN_ON_ONCE(err)) { |
| list_del_init(&va->list); |
| WRITE_ONCE(vp->len, vp->len - 1); |
| } else { |
| va = NULL; |
| } |
| } else { |
| list_move_tail(&va->list, &vp->head); |
| va = NULL; |
| } |
| } |
| spin_unlock(&vn->pool_lock); |
| |
| return va; |
| } |
| |
| static struct vmap_area * |
| node_alloc(unsigned long size, unsigned long align, |
| unsigned long vstart, unsigned long vend, |
| unsigned long *addr, unsigned int *vn_id) |
| { |
| struct vmap_area *va; |
| |
| *vn_id = 0; |
| *addr = vend; |
| |
| /* |
| * Fallback to a global heap if not vmalloc or there |
| * is only one node. |
| */ |
| if (vstart != VMALLOC_START || vend != VMALLOC_END || |
| nr_vmap_nodes == 1) |
| return NULL; |
| |
| *vn_id = raw_smp_processor_id() % nr_vmap_nodes; |
| va = node_pool_del_va(id_to_node(*vn_id), size, align, vstart, vend); |
| *vn_id = encode_vn_id(*vn_id); |
| |
| if (va) |
| *addr = va->va_start; |
| |
| return va; |
| } |
| |
| static inline void setup_vmalloc_vm(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; |
| } |
| |
| /* |
| * Allocate a region of KVA of the specified size and alignment, within the |
| * vstart and vend. If vm is passed in, the two will also be bound. |
| */ |
| 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 vm_struct *vm) |
| { |
| struct vmap_node *vn; |
| struct vmap_area *va; |
| unsigned long freed; |
| unsigned long addr; |
| unsigned int vn_id; |
| 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(); |
| |
| /* |
| * If a VA is obtained from a global heap(if it fails here) |
| * it is anyway marked with this "vn_id" so it is returned |
| * to this pool's node later. Such way gives a possibility |
| * to populate pools based on users demand. |
| * |
| * On success a ready to go VA is returned. |
| */ |
| va = node_alloc(size, align, vstart, vend, &addr, &vn_id); |
| if (!va) { |
| 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: |
| if (addr == vend) { |
| 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 | vn_id); |
| |
| if (vm) { |
| vm->addr = (void *)va->va_start; |
| vm->size = va->va_end - va->va_start; |
| va->vm = vm; |
| } |
| |
| vn = addr_to_node(va->va_start); |
| |
| spin_lock(&vn->busy.lock); |
| insert_vmap_area(va, &vn->busy.root, &vn->busy.head); |
| spin_unlock(&vn->busy.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("vmalloc_node_range for size %lu failed: Address range restricted to %#lx - %#lx\n", |
| size, vstart, vend); |
| |
| 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); |
| static cpumask_t purge_nodes; |
| |
| static void |
| reclaim_list_global(struct list_head *head) |
| { |
| struct vmap_area *va, *n; |
| |
| if (list_empty(head)) |
| return; |
| |
| spin_lock(&free_vmap_area_lock); |
| list_for_each_entry_safe(va, n, head, list) |
| merge_or_add_vmap_area_augment(va, |
| &free_vmap_area_root, &free_vmap_area_list); |
| spin_unlock(&free_vmap_area_lock); |
| } |
| |
| static void |
| decay_va_pool_node(struct vmap_node *vn, bool full_decay) |
| { |
| struct vmap_area *va, *nva; |
| struct list_head decay_list; |
| struct rb_root decay_root; |
| unsigned long n_decay; |
| int i; |
| |
| decay_root = RB_ROOT; |
| INIT_LIST_HEAD(&decay_list); |
| |
| for (i = 0; i < MAX_VA_SIZE_PAGES; i++) { |
| struct list_head tmp_list; |
| |
| if (list_empty(&vn->pool[i].head)) |
| continue; |
| |
| INIT_LIST_HEAD(&tmp_list); |
| |
| /* Detach the pool, so no-one can access it. */ |
| spin_lock(&vn->pool_lock); |
| list_replace_init(&vn->pool[i].head, &tmp_list); |
| spin_unlock(&vn->pool_lock); |
| |
| if (full_decay) |
| WRITE_ONCE(vn->pool[i].len, 0); |
| |
| /* Decay a pool by ~25% out of left objects. */ |
| n_decay = vn->pool[i].len >> 2; |
| |
| list_for_each_entry_safe(va, nva, &tmp_list, list) { |
| list_del_init(&va->list); |
| merge_or_add_vmap_area(va, &decay_root, &decay_list); |
| |
| if (!full_decay) { |
| WRITE_ONCE(vn->pool[i].len, vn->pool[i].len - 1); |
| |
| if (!--n_decay) |
| break; |
| } |
| } |
| |
| /* |
| * Attach the pool back if it has been partly decayed. |
| * Please note, it is supposed that nobody(other contexts) |
| * can populate the pool therefore a simple list replace |
| * operation takes place here. |
| */ |
| if (!full_decay && !list_empty(&tmp_list)) { |
| spin_lock(&vn->pool_lock); |
| list_replace_init(&tmp_list, &vn->pool[i].head); |
| spin_unlock(&vn->pool_lock); |
| } |
| } |
| |
| reclaim_list_global(&decay_list); |
| } |
| |
| static void purge_vmap_node(struct work_struct *work) |
| { |
| struct vmap_node *vn = container_of(work, |
| struct vmap_node, purge_work); |
| unsigned long nr_purged_pages = 0; |
| struct vmap_area *va, *n_va; |
| LIST_HEAD(local_list); |
| |
| vn->nr_purged = 0; |
| |
| list_for_each_entry_safe(va, n_va, &vn->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; |
| unsigned int vn_id = decode_vn_id(va->flags); |
| |
| list_del_init(&va->list); |
| |
| if (is_vmalloc_or_module_addr((void *)orig_start)) |
| kasan_release_vmalloc(orig_start, orig_end, |
| va->va_start, va->va_end); |
| |
| nr_purged_pages += nr; |
| vn->nr_purged++; |
| |
| if (is_vn_id_valid(vn_id) && !vn->skip_populate) |
| if (node_pool_add_va(vn, va)) |
| continue; |
| |
| /* Go back to global. */ |
| list_add(&va->list, &local_list); |
| } |
| |
| atomic_long_sub(nr_purged_pages, &vmap_lazy_nr); |
| |
| reclaim_list_global(&local_list); |
| } |
| |
| /* |
| * Purges all lazily-freed vmap areas. |
| */ |
| static bool __purge_vmap_area_lazy(unsigned long start, unsigned long end, |
| bool full_pool_decay) |
| { |
| unsigned long nr_purged_areas = 0; |
| unsigned int nr_purge_helpers; |
| unsigned int nr_purge_nodes; |
| struct vmap_node *vn; |
| int i; |
| |
| lockdep_assert_held(&vmap_purge_lock); |
| |
| /* |
| * Use cpumask to mark which node has to be processed. |
| */ |
| purge_nodes = CPU_MASK_NONE; |
| |
| for (i = 0; i < nr_vmap_nodes; i++) { |
| vn = &vmap_nodes[i]; |
| |
| INIT_LIST_HEAD(&vn->purge_list); |
| vn->skip_populate = full_pool_decay; |
| decay_va_pool_node(vn, full_pool_decay); |
| |
| if (RB_EMPTY_ROOT(&vn->lazy.root)) |
| continue; |
| |
| spin_lock(&vn->lazy.lock); |
| WRITE_ONCE(vn->lazy.root.rb_node, NULL); |
| list_replace_init(&vn->lazy.head, &vn->purge_list); |
| spin_unlock(&vn->lazy.lock); |
| |
| start = min(start, list_first_entry(&vn->purge_list, |
| struct vmap_area, list)->va_start); |
| |
| end = max(end, list_last_entry(&vn->purge_list, |
| struct vmap_area, list)->va_end); |
| |
| cpumask_set_cpu(i, &purge_nodes); |
| } |
| |
| nr_purge_nodes = cpumask_weight(&purge_nodes); |
| if (nr_purge_nodes > 0) { |
| flush_tlb_kernel_range(start, end); |
| |
| /* One extra worker is per a lazy_max_pages() full set minus one. */ |
| nr_purge_helpers = atomic_long_read(&vmap_lazy_nr) / lazy_max_pages(); |
| nr_purge_helpers = clamp(nr_purge_helpers, 1U, nr_purge_nodes) - 1; |
| |
| for_each_cpu(i, &purge_nodes) { |
| vn = &vmap_nodes[i]; |
| |
| if (nr_purge_helpers > 0) { |
| INIT_WORK(&vn->purge_work, purge_vmap_node); |
| |
| if (cpumask_test_cpu(i, cpu_online_mask)) |
| schedule_work_on(i, &vn->purge_work); |
| else |
| schedule_work(&vn->purge_work); |
| |
| nr_purge_helpers--; |
| } else { |
| vn->purge_work.func = NULL; |
| purge_vmap_node(&vn->purge_work); |
| nr_purged_areas += vn->nr_purged; |
| } |
| } |
| |
| for_each_cpu(i, &purge_nodes) { |
| vn = &vmap_nodes[i]; |
| |
| if (vn->purge_work.func) { |
| flush_work(&vn->purge_work); |
| nr_purged_areas += vn->nr_purged; |
| } |
| } |
| } |
| |
| trace_purge_vmap_area_lazy(start, end, nr_purged_areas); |
| return nr_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, true); |
| mutex_unlock(&vmap_purge_lock); |
| } |
| |
| static void drain_vmap_area_work(struct work_struct *work) |
| { |
| mutex_lock(&vmap_purge_lock); |
| __purge_vmap_area_lazy(ULONG_MAX, 0, false); |
| mutex_unlock(&vmap_purge_lock); |
| } |
| |
| /* |
| * 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 int vn_id = decode_vn_id(va->flags); |
| struct vmap_node *vn; |
| 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); |
| |
| /* |
| * If it was request by a certain node we would like to |
| * return it to that node, i.e. its pool for later reuse. |
| */ |
| vn = is_vn_id_valid(vn_id) ? |
| id_to_node(vn_id):addr_to_node(va->va_start); |
| |
| spin_lock(&vn->lazy.lock); |
| insert_vmap_area(va, &vn->lazy.root, &vn->lazy.head); |
| spin_unlock(&vn->lazy.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_node *vn; |
| struct vmap_area *va; |
| int i, j; |
| |
| if (unlikely(!vmap_initialized)) |
| return NULL; |
| |
| /* |
| * An addr_to_node_id(addr) converts an address to a node index |
| * where a VA is located. If VA spans several zones and passed |
| * addr is not the same as va->va_start, what is not common, we |
| * may need to scan extra nodes. See an example: |
| * |
| * <----va----> |
| * -|-----|-----|-----|-----|- |
| * 1 2 0 1 |
| * |
| * VA resides in node 1 whereas it spans 1, 2 an 0. If passed |
| * addr is within 2 or 0 nodes we should do extra work. |
| */ |
| i = j = addr_to_node_id(addr); |
| do { |
| vn = &vmap_nodes[i]; |
| |
| spin_lock(&vn->busy.lock); |
| va = __find_vmap_area(addr, &vn->busy.root); |
| spin_unlock(&vn->busy.lock); |
| |
| if (va) |
| return va; |
| } while ((i = (i + 1) % nr_vmap_nodes) != j); |
| |
| return NULL; |
| } |
| |
| static struct vmap_area *find_unlink_vmap_area(unsigned long addr) |
| { |
| struct vmap_node *vn; |
| struct vmap_area *va; |
| int i, j; |
| |
| /* |
| * Check the comment in the find_vmap_area() about the loop. |
| */ |
| i = j = addr_to_node_id(addr); |
| do { |
| vn = &vmap_nodes[i]; |
| |
| spin_lock(&vn->busy.lock); |
| va = __find_vmap_area(addr, &vn->busy.root); |
| if (va) |
| unlink_va(va, &vn->busy.root); |
| spin_unlock(&vn->busy.lock); |
| |
| if (va) |
| return va; |
| } while ((i = (i + 1) % nr_vmap_nodes) != j); |
| |
| return NULL; |
| } |
| |
| /*** 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; |
| unsigned int cpu; |
| }; |
| |
| /* 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) % nr_cpu_ids; |
| |
| /* |
| * Please note, nr_cpu_ids points on a highest set |
| * possible bit, i.e. we never invoke cpumask_next() |
| * if an index points on it which is nr_cpu_ids - 1. |
| */ |
| if (!cpu_possible(index)) |
| index = cpumask_next(index, cpu_possible_mask); |
| |
| 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, NULL); |
| 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); |
| vb->cpu = raw_smp_processor_id(); |
| |
| 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); |
| } |
| /* |
| * list_add_tail_rcu could happened in another core |
| * rather than vb->cpu due to task migration, which |
| * is safe as list_add_tail_rcu will ensure the list's |
| * integrity together with list_for_each_rcu from read |
| * side. |
| */ |
| vbq = per_cpu_ptr(&vmap_block_queue, vb->cpu); |
| 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_node *vn; |
| 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); |
| |
| vn = addr_to_node(vb->va->va_start); |
| spin_lock(&vn->busy.lock); |
| unlink_va(vb->va, &vn->busy.root); |
| spin_unlock(&vn->busy.lock); |
| |
| free_vmap_area_noflush(vb->va); |
| kfree_rcu(vb, rcu_head); |
| } |
| |
| static bool purge_fragmented_block(struct vmap_block *vb, |
| struct list_head *purge_list, bool force_purge) |
| { |
| struct vmap_block_queue *vbq = &per_cpu(vmap_block_queue, vb->cpu); |
| |
| 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, &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 ERR_PTR(-EINVAL); |
| } |
| 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, &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, false) && 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, |
| NULL); |
| 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 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; |
| |
| area->flags = flags; |
| area->caller = caller; |
| |
| va = alloc_vmap_area(size, align, start, end, node, gfp_mask, 0, area); |
| if (IS_ERR(va)) { |
| kfree(area); |
| return NULL; |
| } |
| |
| /* |
| * 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 = gfp & __GFP_NOFAIL; |
| 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_noprof(bulk_gfp, |
| nr_pages_request, |
| pages + nr_allocated); |
| |
| else |
| nr = alloc_pages_bulk_array_node_noprof(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; |
| } |
| |
| /* High-order pages or fallback path if "bulk" fails. */ |
| while (nr_allocated < nr_pages) { |
| if (!nofail && fatal_signal_pending(current)) |
| break; |
| |
| if (nid == NUMA_NO_NODE) |
| page = alloc_pages_noprof(alloc_gfp, order); |
| else |
| page = alloc_pages_node_noprof(nid, alloc_gfp, order); |
| if (unlikely(!page)) |
| break; |
| |
| /* |
| * 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_noprof(array_size, 1, nested_gfp, node, |
| area->caller); |
| } else { |
| area->pages = kmalloc_node_noprof(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_noprof(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_noprof(unsigned long size, unsigned long align, |
| gfp_t gfp_mask, int node, const void *caller) |
| { |
| return __vmalloc_node_range_noprof(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_noprof); |
| #endif |
| |
| void *__vmalloc_noprof(unsigned long size, gfp_t gfp_mask) |
| { |
| return __vmalloc_node_noprof(size, 1, gfp_mask, NUMA_NO_NODE, |
| __builtin_return_address(0)); |
| } |
| EXPORT_SYMBOL(__vmalloc_noprof); |
| |
| /** |
| * 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_noprof(unsigned long size) |
| { |
| return __vmalloc_node_noprof(size, 1, GFP_KERNEL, NUMA_NO_NODE, |
| __builtin_return_address(0)); |
| } |
| EXPORT_SYMBOL(vmalloc_noprof); |
| |
| /** |
| * 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_noprof(unsigned long size, gfp_t gfp_mask) |
| { |
| return __vmalloc_node_range_noprof(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_noprof); |
| |
| /** |
| * 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_noprof(unsigned long size) |
| { |
| return __vmalloc_node_noprof(size, 1, GFP_KERNEL | __GFP_ZERO, NUMA_NO_NODE, |
| __builtin_return_address(0)); |
| } |
| EXPORT_SYMBOL(vzalloc_noprof); |
| |
| /** |
| * 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_noprof(unsigned long size) |
| { |
| return __vmalloc_node_range_noprof(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_noprof); |
| |
| /** |
| * 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_noprof(unsigned long size, int node) |
| { |
| return __vmalloc_node_noprof(size, 1, GFP_KERNEL, node, |
| __builtin_return_address(0)); |
| } |
| EXPORT_SYMBOL(vmalloc_node_noprof); |
| |
| /** |
| * 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_noprof(unsigned long size, int node) |
| { |
| return __vmalloc_node_noprof(size, 1, GFP_KERNEL | __GFP_ZERO, node, |
| __builtin_return_address(0)); |
| } |
| EXPORT_SYMBOL(vzalloc_node_noprof); |
| |
| #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_noprof(unsigned long size) |
| { |
| return __vmalloc_node_noprof(size, 1, GFP_VMALLOC32, NUMA_NO_NODE, |
| __builtin_return_address(0)); |
| } |
| EXPORT_SYMBOL(vmalloc_32_noprof); |
| |
| /** |
| * 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_noprof(unsigned long size) |
| { |
| return __vmalloc_node_range_noprof(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_noprof); |
| |
| /* |
| * 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_node *vn; |
| struct vmap_area *va; |
| struct vm_struct *vm; |
| char *vaddr; |
| size_t n, size, flags, remains; |
| unsigned long next; |
| |
| addr = kasan_reset_tag(addr); |
| |
| /* Don't allow overflow */ |
| if ((unsigned long) addr + count < count) |
| count = -(unsigned long) addr; |
| |
| remains = count; |
| |
| vn = find_vmap_area_exceed_addr_lock((unsigned long) addr, &va); |
| if (!vn) |
| goto finished_zero; |
| |
| /* no intersects with alive vmap_area */ |
| if ((unsigned long)addr + remains <= va->va_start) |
| goto finished_zero; |
| |
| do { |
| 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) |
| goto next_va; |
| |
| if (vm && (vm->flags & VM_UNINITIALIZED)) |
| goto next_va; |
| |
| /* 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) |
| goto next_va; |
| |
| 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 && (vm->flags & (VM_IOREMAP | VM_SPARSE)))) |
| copied = aligned_vread_iter(iter, addr, n); |
| else /* IOREMAP | SPARSE area is treated as memory hole */ |
| copied = zero_iter(iter, n); |
| |
| addr += copied; |
| remains -= copied; |
| |
| if (copied != n) |
| goto finished; |
| |
| next_va: |
| next = va->va_end; |
| spin_unlock(&vn->busy.lock); |
| } while ((vn = find_vmap_area_exceed_addr_lock(next, &va))); |
| |
| finished_zero: |
| if (vn) |
| spin_unlock(&vn->busy.lock); |
| |
| /* zero-fill memory holes */ |
| return count - remains + zero_iter(iter, remains); |
| finished: |
| /* Nothing remains, or We couldn't copy/zero everything. */ |
| if (vn) |
| spin_unlock(&vn->busy.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 = va_clip(&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 */ |
| for (area = 0; area < nr_vms; area++) { |
| struct vmap_node *vn = addr_to_node(vas[area]->va_start); |
| |
| spin_lock(&vn->busy.lock); |
| insert_vmap_area(vas[area], &vn->busy.root, &vn->busy.head); |
| setup_vmalloc_vm(vms[area], vas[area], VM_ALLOC, |
| pcpu_get_vm_areas); |
| spin_unlock(&vn->busy.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) |
| { |
| const void *caller; |
| struct vm_struct *vm; |
| struct vmap_area *va; |
| struct vmap_node *vn; |
| unsigned long addr; |
| unsigned int nr_pages; |
| |
| addr = PAGE_ALIGN((unsigned long) object); |
| vn = addr_to_node(addr); |
| |
| if (!spin_trylock(&vn->busy.lock)) |
| return false; |
| |
| va = __find_vmap_area(addr, &vn->busy.root); |
| if (!va || !va->vm) { |
| spin_unlock(&vn->busy.lock); |
| return false; |
| } |
| |
| vm = va->vm; |
| addr = (unsigned long) vm->addr; |
| caller = vm->caller; |
| nr_pages = vm->nr_pages; |
| spin_unlock(&vn->busy.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 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_node *vn; |
| struct vmap_area *va; |
| int i; |
| |
| for (i = 0; i < nr_vmap_nodes; i++) { |
| vn = &vmap_nodes[i]; |
| |
| spin_lock(&vn->lazy.lock); |
| list_for_each_entry(va, &vn->lazy.head, 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(&vn->lazy.lock); |
| } |
| } |
| |
| static int vmalloc_info_show(struct seq_file *m, void *p) |
| { |
| struct vmap_node *vn; |
| struct vmap_area *va; |
| struct vm_struct *v; |
| int i; |
| |
| for (i = 0; i < nr_vmap_nodes; i++) { |
| vn = &vmap_nodes[i]; |
| |
| spin_lock(&vn->busy.lock); |
| list_for_each_entry(va, &vn->busy.head, 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); |
| |
| continue; |
| } |
| |
| 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_SPARSE) |
| seq_puts(m, " sparse"); |
| |
| 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'); |
| } |
| spin_unlock(&vn->busy.lock); |
| } |
| |
| /* |
| * As a final step, dump "unpurged" areas. |
| */ |
| show_purge_info(m); |
| return 0; |
| } |
| |
| static int __init proc_vmalloc_init(void) |
| { |
| void *priv_data = NULL; |
| |
| if (IS_ENABLED(CONFIG_NUMA)) |
| priv_data = kmalloc(nr_node_ids * sizeof(unsigned int), GFP_KERNEL); |
| |
| proc_create_single_data("vmallocinfo", |
| 0400, NULL, vmalloc_info_show, priv_data); |
| |
| return 0; |
| } |
| module_init(proc_vmalloc_init); |
| |
| #endif |
| |
| static void __init vmap_init_free_space(void) |
| { |
| unsigned long vmap_start = 1; |
| const unsigned long vmap_end = ULONG_MAX; |
| struct vmap_area *free; |
| struct vm_struct *busy; |
| |
| /* |
| * B F B B B F |
| * -|-----|.....|-----|-----|-----|.....|- |
| * | The KVA space | |
| * |<--------------------------------->| |
| */ |
| for (busy = vmlist; busy; busy = busy->next) { |
| if ((unsigned long) busy->addr - 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 = (unsigned long) busy->addr; |
| |
| insert_vmap_area_augment(free, NULL, |
| &free_vmap_area_root, |
| &free_vmap_area_list); |
| } |
| } |
| |
| vmap_start = (unsigned long) busy->addr + busy->size; |
| } |
| |
| 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 void vmap_init_nodes(void) |
| { |
| struct vmap_node *vn; |
| int i, n; |
| |
| #if BITS_PER_LONG == 64 |
| /* |
| * A high threshold of max nodes is fixed and bound to 128, |
| * thus a scale factor is 1 for systems where number of cores |
| * are less or equal to specified threshold. |
| * |
| * As for NUMA-aware notes. For bigger systems, for example |
| * NUMA with multi-sockets, where we can end-up with thousands |
| * of cores in total, a "sub-numa-clustering" should be added. |
| * |
| * In this case a NUMA domain is considered as a single entity |
| * with dedicated sub-nodes in it which describe one group or |
| * set of cores. Therefore a per-domain purging is supposed to |
| * be added as well as a per-domain balancing. |
| */ |
| n = clamp_t(unsigned int, num_possible_cpus(), 1, 128); |
| |
| if (n > 1) { |
| vn = kmalloc_array(n, sizeof(*vn), GFP_NOWAIT | __GFP_NOWARN); |
| if (vn) { |
| /* Node partition is 16 pages. */ |
| vmap_zone_size = (1 << 4) * PAGE_SIZE; |
| nr_vmap_nodes = n; |
| vmap_nodes = vn; |
| } else { |
| pr_err("Failed to allocate an array. Disable a node layer\n"); |
| } |
| } |
| #endif |
| |
| for (n = 0; n < nr_vmap_nodes; n++) { |
| vn = &vmap_nodes[n]; |
| vn->busy.root = RB_ROOT; |
| INIT_LIST_HEAD(&vn->busy.head); |
| spin_lock_init(&vn->busy.lock); |
| |
| vn->lazy.root = RB_ROOT; |
| INIT_LIST_HEAD(&vn->lazy.head); |
| spin_lock_init(&vn->lazy.lock); |
| |
| for (i = 0; i < MAX_VA_SIZE_PAGES; i++) { |
| INIT_LIST_HEAD(&vn->pool[i].head); |
| WRITE_ONCE(vn->pool[i].len, 0); |
| } |
| |
| spin_lock_init(&vn->pool_lock); |
| } |
| } |
| |
| static unsigned long |
| vmap_node_shrink_count(struct shrinker *shrink, struct shrink_control *sc) |
| { |
| unsigned long count; |
| struct vmap_node *vn; |
| int i, j; |
| |
| for (count = 0, i = 0; i < nr_vmap_nodes; i++) { |
| vn = &vmap_nodes[i]; |
| |
| for (j = 0; j < MAX_VA_SIZE_PAGES; j++) |
| count += READ_ONCE(vn->pool[j].len); |
| } |
| |
| return count ? count : SHRINK_EMPTY; |
| } |
| |
| static unsigned long |
| vmap_node_shrink_scan(struct shrinker *shrink, struct shrink_control *sc) |
| { |
| int i; |
| |
| for (i = 0; i < nr_vmap_nodes; i++) |
| decay_va_pool_node(&vmap_nodes[i], true); |
| |
| return SHRINK_STOP; |
| } |
| |
| void __init vmalloc_init(void) |
| { |
| struct shrinker *vmap_node_shrinker; |
| struct vmap_area *va; |
| struct vmap_node *vn; |
| 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); |
| } |
| |
| /* |
| * Setup nodes before importing vmlist. |
| */ |
| vmap_init_nodes(); |
| |
| /* 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; |
| |
| vn = addr_to_node(va->va_start); |
| insert_vmap_area(va, &vn->busy.root, &vn->busy.head); |
| } |
| |
| /* |
| * Now we can initialize a free vmap space. |
| */ |
| vmap_init_free_space(); |
| vmap_initialized = true; |
| |
| vmap_node_shrinker = shrinker_alloc(0, "vmap-node"); |
| if (!vmap_node_shrinker) { |
| pr_err("Failed to allocate vmap-node shrinker!\n"); |
| return; |
| } |
| |
| vmap_node_shrinker->count_objects = vmap_node_shrink_count; |
| vmap_node_shrinker->scan_objects = vmap_node_shrink_scan; |
| shrinker_register(vmap_node_shrinker); |
| } |