Adding upstream version 6.6.15.upstream/6.6.15

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 4495 insertions, 0 deletions

diff --git a/mm/vmalloc.c b/mm/vmalloc.c
new file mode 100644
index 0000000000..a3fedb3ee0
--- /dev/null
+++ b/mm/vmalloc.c
@@ -0,0 +1,4495 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ *  Copyright (C) 1993  Linus Torvalds
+ *  Support of BIGMEM added by Gerhard Wichert, Siemens AG, July 1999
+ *  SMP-safe vmalloc/vfree/ioremap, Tigran Aivazian <tigran@veritas.com>, May 2000
+ *  Major rework to support vmap/vunmap, Christoph Hellwig, SGI, August 2002
+ *  Numa awareness, Christoph Lameter, SGI, June 2005
+ *  Improving global KVA allocator, Uladzislau Rezki, Sony, May 2019
+ */
+
+#include <linux/vmalloc.h>
+#include <linux/mm.h>
+#include <linux/module.h>
+#include <linux/highmem.h>
+#include <linux/sched/signal.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+#include <linux/interrupt.h>
+#include <linux/proc_fs.h>
+#include <linux/seq_file.h>
+#include <linux/set_memory.h>
+#include <linux/debugobjects.h>
+#include <linux/kallsyms.h>
+#include <linux/list.h>
+#include <linux/notifier.h>
+#include <linux/rbtree.h>
+#include <linux/xarray.h>
+#include <linux/io.h>
+#include <linux/rcupdate.h>
+#include <linux/pfn.h>
+#include <linux/kmemleak.h>
+#include <linux/atomic.h>
+#include <linux/compiler.h>
+#include <linux/memcontrol.h>
+#include <linux/llist.h>
+#include <linux/uio.h>
+#include <linux/bitops.h>
+#include <linux/rbtree_augmented.h>
+#include <linux/overflow.h>
+#include <linux/pgtable.h>
+#include <linux/hugetlb.h>
+#include <linux/sched/mm.h>
+#include <asm/tlbflush.h>
+#include <asm/shmparam.h>
+
+#define CREATE_TRACE_POINTS
+#include <trace/events/vmalloc.h>
+
+#include "internal.h"
+#include "pgalloc-track.h"
+
+#ifdef CONFIG_HAVE_ARCH_HUGE_VMAP
+static unsigned int __ro_after_init ioremap_max_page_shift = BITS_PER_LONG - 1;
+
+static int __init set_nohugeiomap(char *str)
+{
+	ioremap_max_page_shift = PAGE_SHIFT;
+	return 0;
+}
+early_param("nohugeiomap", set_nohugeiomap);
+#else /* CONFIG_HAVE_ARCH_HUGE_VMAP */
+static const unsigned int ioremap_max_page_shift = PAGE_SHIFT;
+#endif	/* CONFIG_HAVE_ARCH_HUGE_VMAP */
+
+#ifdef CONFIG_HAVE_ARCH_HUGE_VMALLOC
+static bool __ro_after_init vmap_allow_huge = true;
+
+static int __init set_nohugevmalloc(char *str)
+{
+	vmap_allow_huge = false;
+	return 0;
+}
+early_param("nohugevmalloc", set_nohugevmalloc);
+#else /* CONFIG_HAVE_ARCH_HUGE_VMALLOC */
+static const bool vmap_allow_huge = false;
+#endif	/* CONFIG_HAVE_ARCH_HUGE_VMALLOC */
+
+bool is_vmalloc_addr(const void *x)
+{
+	unsigned long addr = (unsigned long)kasan_reset_tag(x);
+
+	return addr >= VMALLOC_START && addr < VMALLOC_END;
+}
+EXPORT_SYMBOL(is_vmalloc_addr);
+
+struct vfree_deferred {
+	struct llist_head list;
+	struct work_struct wq;
+};
+static DEFINE_PER_CPU(struct vfree_deferred, vfree_deferred);
+
+/*** Page table manipulation functions ***/
+static int vmap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
+			phys_addr_t phys_addr, pgprot_t prot,
+			unsigned int max_page_shift, pgtbl_mod_mask *mask)
+{
+	pte_t *pte;
+	u64 pfn;
+	unsigned long size = PAGE_SIZE;
+
+	pfn = phys_addr >> PAGE_SHIFT;
+	pte = pte_alloc_kernel_track(pmd, addr, mask);
+	if (!pte)
+		return -ENOMEM;
+	do {
+		BUG_ON(!pte_none(ptep_get(pte)));
+
+#ifdef CONFIG_HUGETLB_PAGE
+		size = arch_vmap_pte_range_map_size(addr, end, pfn, max_page_shift);
+		if (size != PAGE_SIZE) {
+			pte_t entry = pfn_pte(pfn, prot);
+
+			entry = arch_make_huge_pte(entry, ilog2(size), 0);
+			set_huge_pte_at(&init_mm, addr, pte, entry, size);
+			pfn += PFN_DOWN(size);
+			continue;
+		}
+#endif
+		set_pte_at(&init_mm, addr, pte, pfn_pte(pfn, prot));
+		pfn++;
+	} while (pte += PFN_DOWN(size), addr += size, addr != end);
+	*mask |= PGTBL_PTE_MODIFIED;
+	return 0;
+}
+
+static int vmap_try_huge_pmd(pmd_t *pmd, unsigned long addr, unsigned long end,
+			phys_addr_t phys_addr, pgprot_t prot,
+			unsigned int max_page_shift)
+{
+	if (max_page_shift < PMD_SHIFT)
+		return 0;
+
+	if (!arch_vmap_pmd_supported(prot))
+		return 0;
+
+	if ((end - addr) != PMD_SIZE)
+		return 0;
+
+	if (!IS_ALIGNED(addr, PMD_SIZE))
+		return 0;
+
+	if (!IS_ALIGNED(phys_addr, PMD_SIZE))
+		return 0;
+
+	if (pmd_present(*pmd) && !pmd_free_pte_page(pmd, addr))
+		return 0;
+
+	return pmd_set_huge(pmd, phys_addr, prot);
+}
+
+static int vmap_pmd_range(pud_t *pud, unsigned long addr, unsigned long end,
+			phys_addr_t phys_addr, pgprot_t prot,
+			unsigned int max_page_shift, pgtbl_mod_mask *mask)
+{
+	pmd_t *pmd;
+	unsigned long next;
+
+	pmd = pmd_alloc_track(&init_mm, pud, addr, mask);
+	if (!pmd)
+		return -ENOMEM;
+	do {
+		next = pmd_addr_end(addr, end);
+
+		if (vmap_try_huge_pmd(pmd, addr, next, phys_addr, prot,
+					max_page_shift)) {
+			*mask |= PGTBL_PMD_MODIFIED;
+			continue;
+		}
+
+		if (vmap_pte_range(pmd, addr, next, phys_addr, prot, max_page_shift, mask))
+			return -ENOMEM;
+	} while (pmd++, phys_addr += (next - addr), addr = next, addr != end);
+	return 0;
+}
+
+static int vmap_try_huge_pud(pud_t *pud, unsigned long addr, unsigned long end,
+			phys_addr_t phys_addr, pgprot_t prot,
+			unsigned int max_page_shift)
+{
+	if (max_page_shift < PUD_SHIFT)
+		return 0;
+
+	if (!arch_vmap_pud_supported(prot))
+		return 0;
+
+	if ((end - addr) != PUD_SIZE)
+		return 0;
+
+	if (!IS_ALIGNED(addr, PUD_SIZE))
+		return 0;
+
+	if (!IS_ALIGNED(phys_addr, PUD_SIZE))
+		return 0;
+
+	if (pud_present(*pud) && !pud_free_pmd_page(pud, addr))
+		return 0;
+
+	return pud_set_huge(pud, phys_addr, prot);
+}
+
+static int vmap_pud_range(p4d_t *p4d, unsigned long addr, unsigned long end,
+			phys_addr_t phys_addr, pgprot_t prot,
+			unsigned int max_page_shift, pgtbl_mod_mask *mask)
+{
+	pud_t *pud;
+	unsigned long next;
+
+	pud = pud_alloc_track(&init_mm, p4d, addr, mask);
+	if (!pud)
+		return -ENOMEM;
+	do {
+		next = pud_addr_end(addr, end);
+
+		if (vmap_try_huge_pud(pud, addr, next, phys_addr, prot,
+					max_page_shift)) {
+			*mask |= PGTBL_PUD_MODIFIED;
+			continue;
+		}
+
+		if (vmap_pmd_range(pud, addr, next, phys_addr, prot,
+					max_page_shift, mask))
+			return -ENOMEM;
+	} while (pud++, phys_addr += (next - addr), addr = next, addr != end);
+	return 0;
+}
+
+static int vmap_try_huge_p4d(p4d_t *p4d, unsigned long addr, unsigned long end,
+			phys_addr_t phys_addr, pgprot_t prot,
+			unsigned int max_page_shift)
+{
+	if (max_page_shift < P4D_SHIFT)
+		return 0;
+
+	if (!arch_vmap_p4d_supported(prot))
+		return 0;
+
+	if ((end - addr) != P4D_SIZE)
+		return 0;
+
+	if (!IS_ALIGNED(addr, P4D_SIZE))
+		return 0;
+
+	if (!IS_ALIGNED(phys_addr, P4D_SIZE))
+		return 0;
+
+	if (p4d_present(*p4d) && !p4d_free_pud_page(p4d, addr))
+		return 0;
+
+	return p4d_set_huge(p4d, phys_addr, prot);
+}
+
+static int vmap_p4d_range(pgd_t *pgd, unsigned long addr, unsigned long end,
+			phys_addr_t phys_addr, pgprot_t prot,
+			unsigned int max_page_shift, pgtbl_mod_mask *mask)
+{
+	p4d_t *p4d;
+	unsigned long next;
+
+	p4d = p4d_alloc_track(&init_mm, pgd, addr, mask);
+	if (!p4d)
+		return -ENOMEM;
+	do {
+		next = p4d_addr_end(addr, end);
+
+		if (vmap_try_huge_p4d(p4d, addr, next, phys_addr, prot,
+					max_page_shift)) {
+			*mask |= PGTBL_P4D_MODIFIED;
+			continue;
+		}
+
+		if (vmap_pud_range(p4d, addr, next, phys_addr, prot,
+					max_page_shift, mask))
+			return -ENOMEM;
+	} while (p4d++, phys_addr += (next - addr), addr = next, addr != end);
+	return 0;
+}
+
+static int vmap_range_noflush(unsigned long addr, unsigned long end,
+			phys_addr_t phys_addr, pgprot_t prot,
+			unsigned int max_page_shift)
+{
+	pgd_t *pgd;
+	unsigned long start;
+	unsigned long next;
+	int err;
+	pgtbl_mod_mask mask = 0;
+
+	might_sleep();
+	BUG_ON(addr >= end);
+
+	start = addr;
+	pgd = pgd_offset_k(addr);
+	do {
+		next = pgd_addr_end(addr, end);
+		err = vmap_p4d_range(pgd, addr, next, phys_addr, prot,
+					max_page_shift, &mask);
+		if (err)
+			break;
+	} while (pgd++, phys_addr += (next - addr), addr = next, addr != end);
+
+	if (mask & ARCH_PAGE_TABLE_SYNC_MASK)
+		arch_sync_kernel_mappings(start, end);
+
+	return err;
+}
+
+int ioremap_page_range(unsigned long addr, unsigned long end,
+		phys_addr_t phys_addr, pgprot_t prot)
+{
+	int err;
+
+	err = vmap_range_noflush(addr, end, phys_addr, pgprot_nx(prot),
+				 ioremap_max_page_shift);
+	flush_cache_vmap(addr, end);
+	if (!err)
+		err = kmsan_ioremap_page_range(addr, end, phys_addr, prot,
+					       ioremap_max_page_shift);
+	return err;
+}
+
+static void vunmap_pte_range(pmd_t *pmd, unsigned long addr, unsigned long end,
+			     pgtbl_mod_mask *mask)
+{
+	pte_t *pte;
+
+	pte = pte_offset_kernel(pmd, addr);
+	do {
+		pte_t ptent = ptep_get_and_clear(&init_mm, addr, pte);
+		WARN_ON(!pte_none(ptent) && !pte_present(ptent));
+	} while (pte++, addr += PAGE_SIZE, addr != end);
+	*mask |= PGTBL_PTE_MODIFIED;
+}
+
+static void vunmap_pmd_range(pud_t *pud, unsigned long addr, unsigned long end,
+			     pgtbl_mod_mask *mask)
+{
+	pmd_t *pmd;
+	unsigned long next;
+	int cleared;
+
+	pmd = pmd_offset(pud, addr);
+	do {
+		next = pmd_addr_end(addr, end);
+
+		cleared = pmd_clear_huge(pmd);
+		if (cleared || pmd_bad(*pmd))
+			*mask |= PGTBL_PMD_MODIFIED;
+
+		if (cleared)
+			continue;
+		if (pmd_none_or_clear_bad(pmd))
+			continue;
+		vunmap_pte_range(pmd, addr, next, mask);
+
+		cond_resched();
+	} while (pmd++, addr = next, addr != end);
+}
+
+static void vunmap_pud_range(p4d_t *p4d, unsigned long addr, unsigned long end,
+			     pgtbl_mod_mask *mask)
+{
+	pud_t *pud;
+	unsigned long next;
+	int cleared;
+
+	pud = pud_offset(p4d, addr);
+	do {
+		next = pud_addr_end(addr, end);
+
+		cleared = pud_clear_huge(pud);
+		if (cleared || pud_bad(*pud))
+			*mask |= PGTBL_PUD_MODIFIED;
+
+		if (cleared)
+			continue;
+		if (pud_none_or_clear_bad(pud))
+			continue;
+		vunmap_pmd_range(pud, addr, next, mask);
+	} while (pud++, addr = next, addr != end);
+}
+
+static void vunmap_p4d_range(pgd_t *pgd, unsigned long addr, unsigned long end,
+			     pgtbl_mod_mask *mask)
+{
+	p4d_t *p4d;
+	unsigned long next;
+
+	p4d = p4d_offset(pgd, addr);
+	do {
+		next = p4d_addr_end(addr, end);
+
+		p4d_clear_huge(p4d);
+		if (p4d_bad(*p4d))
+			*mask |= PGTBL_P4D_MODIFIED;
+
+		if (p4d_none_or_clear_bad(p4d))
+			continue;
+		vunmap_pud_range(p4d, addr, next, mask);
+	} while (p4d++, addr = next, addr != end);
+}
+
+/*
+ * vunmap_range_noflush is similar to vunmap_range, but does not
+ * flush caches or TLBs.
+ *
+ * The caller is responsible for calling flush_cache_vmap() before calling
+ * this function, and flush_tlb_kernel_range after it has returned
+ * successfully (and before the addresses are expected to cause a page fault
+ * or be re-mapped for something else, if TLB flushes are being delayed or
+ * coalesced).
+ *
+ * This is an internal function only. Do not use outside mm/.
+ */
+void __vunmap_range_noflush(unsigned long start, unsigned long end)
+{
+	unsigned long next;
+	pgd_t *pgd;
+	unsigned long addr = start;
+	pgtbl_mod_mask mask = 0;
+
+	BUG_ON(addr >= end);
+	pgd = pgd_offset_k(addr);
+	do {
+		next = pgd_addr_end(addr, end);
+		if (pgd_bad(*pgd))
+			mask |= PGTBL_PGD_MODIFIED;
+		if (pgd_none_or_clear_bad(pgd))
+			continue;
+		vunmap_p4d_range(pgd, addr, next, &mask);
+	} while (pgd++, addr = next, addr != end);
+
+	if (mask & ARCH_PAGE_TABLE_SYNC_MASK)
+		arch_sync_kernel_mappings(start, end);
+}
+
+void vunmap_range_noflush(unsigned long start, unsigned long end)
+{
+	kmsan_vunmap_range_noflush(start, end);
+	__vunmap_range_noflush(start, end);
+}
+
+/**
+ * vunmap_range - unmap kernel virtual addresses
+ * @addr: start of the VM area to unmap
+ * @end: end of the VM area to unmap (non-inclusive)
+ *
+ * Clears any present PTEs in the virtual address range, flushes TLBs and
+ * caches. Any subsequent access to the address before it has been re-mapped
+ * is a kernel bug.
+ */
+void vunmap_range(unsigned long addr, unsigned long end)
+{
+	flush_cache_vunmap(addr, end);
+	vunmap_range_noflush(addr, end);
+	flush_tlb_kernel_range(addr, end);
+}
+
+static int vmap_pages_pte_range(pmd_t *pmd, unsigned long addr,
+		unsigned long end, pgprot_t prot, struct page **pages, int *nr,
+		pgtbl_mod_mask *mask)
+{
+	pte_t *pte;
+
+	/*
+	 * nr is a running index into the array which helps higher level
+	 * callers keep track of where we're up to.
+	 */
+
+	pte = pte_alloc_kernel_track(pmd, addr, mask);
+	if (!pte)
+		return -ENOMEM;
+	do {
+		struct page *page = pages[*nr];
+
+		if (WARN_ON(!pte_none(ptep_get(pte))))
+			return -EBUSY;
+		if (WARN_ON(!page))
+			return -ENOMEM;
+		if (WARN_ON(!pfn_valid(page_to_pfn(page))))
+			return -EINVAL;
+
+		set_pte_at(&init_mm, addr, pte, mk_pte(page, prot));
+		(*nr)++;
+	} while (pte++, addr += PAGE_SIZE, addr != end);
+	*mask |= PGTBL_PTE_MODIFIED;
+	return 0;
+}
+
+static int vmap_pages_pmd_range(pud_t *pud, unsigned long addr,
+		unsigned long end, pgprot_t prot, struct page **pages, int *nr,
+		pgtbl_mod_mask *mask)
+{
+	pmd_t *pmd;
+	unsigned long next;
+
+	pmd = pmd_alloc_track(&init_mm, pud, addr, mask);
+	if (!pmd)
+		return -ENOMEM;
+	do {
+		next = pmd_addr_end(addr, end);
+		if (vmap_pages_pte_range(pmd, addr, next, prot, pages, nr, mask))
+			return -ENOMEM;
+	} while (pmd++, addr = next, addr != end);
+	return 0;
+}
+
+static int vmap_pages_pud_range(p4d_t *p4d, unsigned long addr,
+		unsigned long end, pgprot_t prot, struct page **pages, int *nr,
+		pgtbl_mod_mask *mask)
+{
+	pud_t *pud;
+	unsigned long next;
+
+	pud = pud_alloc_track(&init_mm, p4d, addr, mask);
+	if (!pud)
+		return -ENOMEM;
+	do {
+		next = pud_addr_end(addr, end);
+		if (vmap_pages_pmd_range(pud, addr, next, prot, pages, nr, mask))
+			return -ENOMEM;
+	} while (pud++, addr = next, addr != end);
+	return 0;
+}
+
+static int vmap_pages_p4d_range(pgd_t *pgd, unsigned long addr,
+		unsigned long end, pgprot_t prot, struct page **pages, int *nr,
+		pgtbl_mod_mask *mask)
+{
+	p4d_t *p4d;
+	unsigned long next;
+
+	p4d = p4d_alloc_track(&init_mm, pgd, addr, mask);
+	if (!p4d)
+		return -ENOMEM;
+	do {
+		next = p4d_addr_end(addr, end);
+		if (vmap_pages_pud_range(p4d, addr, next, prot, pages, nr, mask))
+			return -ENOMEM;
+	} while (p4d++, addr = next, addr != end);
+	return 0;
+}
+
+static int vmap_small_pages_range_noflush(unsigned long addr, unsigned long end,
+		pgprot_t prot, struct page **pages)
+{
+	unsigned long start = addr;
+	pgd_t *pgd;
+	unsigned long next;
+	int err = 0;
+	int nr = 0;
+	pgtbl_mod_mask mask = 0;
+
+	BUG_ON(addr >= end);
+	pgd = pgd_offset_k(addr);
+	do {
+		next = pgd_addr_end(addr, end);
+		if (pgd_bad(*pgd))
+			mask |= PGTBL_PGD_MODIFIED;
+		err = vmap_pages_p4d_range(pgd, addr, next, prot, pages, &nr, &mask);
+		if (err)
+			return err;
+	} while (pgd++, addr = next, addr != end);
+
+	if (mask & ARCH_PAGE_TABLE_SYNC_MASK)
+		arch_sync_kernel_mappings(start, end);
+
+	return 0;
+}
+
+/*
+ * vmap_pages_range_noflush is similar to vmap_pages_range, but does not
+ * flush caches.
+ *
+ * The caller is responsible for calling flush_cache_vmap() after this
+ * function returns successfully and before the addresses are accessed.
+ *
+ * This is an internal function only. Do not use outside mm/.
+ */
+int __vmap_pages_range_noflush(unsigned long addr, unsigned long end,
+		pgprot_t prot, struct page **pages, unsigned int page_shift)
+{
+	unsigned int i, nr = (end - addr) >> PAGE_SHIFT;
+
+	WARN_ON(page_shift < PAGE_SHIFT);
+
+	if (!IS_ENABLED(CONFIG_HAVE_ARCH_HUGE_VMALLOC) ||
+			page_shift == PAGE_SHIFT)
+		return vmap_small_pages_range_noflush(addr, end, prot, pages);
+
+	for (i = 0; i < nr; i += 1U << (page_shift - PAGE_SHIFT)) {
+		int err;
+
+		err = vmap_range_noflush(addr, addr + (1UL << page_shift),
+					page_to_phys(pages[i]), prot,
+					page_shift);
+		if (err)
+			return err;
+
+		addr += 1UL << page_shift;
+	}
+
+	return 0;
+}
+
+int vmap_pages_range_noflush(unsigned long addr, unsigned long end,
+		pgprot_t prot, struct page **pages, unsigned int page_shift)
+{
+	int ret = kmsan_vmap_pages_range_noflush(addr, end, prot, pages,
+						 page_shift);
+
+	if (ret)
+		return ret;
+	return __vmap_pages_range_noflush(addr, end, prot, pages, page_shift);
+}
+
+/**
+ * vmap_pages_range - map pages to a kernel virtual address
+ * @addr: start of the VM area to map
+ * @end: end of the VM area to map (non-inclusive)
+ * @prot: page protection flags to use
+ * @pages: pages to map (always PAGE_SIZE pages)
+ * @page_shift: maximum shift that the pages may be mapped with, @pages must
+ * be aligned and contiguous up to at least this shift.
+ *
+ * RETURNS:
+ * 0 on success, -errno on failure.
+ */
+static int vmap_pages_range(unsigned long addr, unsigned long end,
+		pgprot_t prot, struct page **pages, unsigned int page_shift)
+{
+	int err;
+
+	err = vmap_pages_range_noflush(addr, end, prot, pages, page_shift);
+	flush_cache_vmap(addr, end);
+	return err;
+}
+
+int is_vmalloc_or_module_addr(const void *x)
+{
+	/*
+	 * ARM, x86-64 and sparc64 put modules in a special place,
+	 * and fall back on vmalloc() if that fails. Others
+	 * just put it in the vmalloc space.
+	 */
+#if defined(CONFIG_MODULES) && defined(MODULES_VADDR)
+	unsigned long addr = (unsigned long)kasan_reset_tag(x);
+	if (addr >= MODULES_VADDR && addr < MODULES_END)
+		return 1;
+#endif
+	return is_vmalloc_addr(x);
+}
+EXPORT_SYMBOL_GPL(is_vmalloc_or_module_addr);
+
+/*
+ * Walk a vmap address to the struct page it maps. Huge vmap mappings will
+ * return the tail page that corresponds to the base page address, which
+ * matches small vmap mappings.
+ */
+struct page *vmalloc_to_page(const void *vmalloc_addr)
+{
+	unsigned long addr = (unsigned long) vmalloc_addr;
+	struct page *page = NULL;
+	pgd_t *pgd = pgd_offset_k(addr);
+	p4d_t *p4d;
+	pud_t *pud;
+	pmd_t *pmd;
+	pte_t *ptep, pte;
+
+	/*
+	 * XXX we might need to change this if we add VIRTUAL_BUG_ON for
+	 * architectures that do not vmalloc module space
+	 */
+	VIRTUAL_BUG_ON(!is_vmalloc_or_module_addr(vmalloc_addr));
+
+	if (pgd_none(*pgd))
+		return NULL;
+	if (WARN_ON_ONCE(pgd_leaf(*pgd)))
+		return NULL; /* XXX: no allowance for huge pgd */
+	if (WARN_ON_ONCE(pgd_bad(*pgd)))
+		return NULL;
+
+	p4d = p4d_offset(pgd, addr);
+	if (p4d_none(*p4d))
+		return NULL;
+	if (p4d_leaf(*p4d))
+		return p4d_page(*p4d) + ((addr & ~P4D_MASK) >> PAGE_SHIFT);
+	if (WARN_ON_ONCE(p4d_bad(*p4d)))
+		return NULL;
+
+	pud = pud_offset(p4d, addr);
+	if (pud_none(*pud))
+		return NULL;
+	if (pud_leaf(*pud))
+		return pud_page(*pud) + ((addr & ~PUD_MASK) >> PAGE_SHIFT);
+	if (WARN_ON_ONCE(pud_bad(*pud)))
+		return NULL;
+
+	pmd = pmd_offset(pud, addr);
+	if (pmd_none(*pmd))
+		return NULL;
+	if (pmd_leaf(*pmd))
+		return pmd_page(*pmd) + ((addr & ~PMD_MASK) >> PAGE_SHIFT);
+	if (WARN_ON_ONCE(pmd_bad(*pmd)))
+		return NULL;
+
+	ptep = pte_offset_kernel(pmd, addr);
+	pte = ptep_get(ptep);
+	if (pte_present(pte))
+		page = pte_page(pte);
+
+	return page;
+}
+EXPORT_SYMBOL(vmalloc_to_page);
+
+/*
+ * Map a vmalloc()-space virtual address to the physical page frame number.
+ */
+unsigned long vmalloc_to_pfn(const void *vmalloc_addr)
+{
+	return page_to_pfn(vmalloc_to_page(vmalloc_addr));
+}
+EXPORT_SYMBOL(vmalloc_to_pfn);
+
+
+/*** Global kva allocator ***/
+
+#define DEBUG_AUGMENT_PROPAGATE_CHECK 0
+#define DEBUG_AUGMENT_LOWEST_MATCH_CHECK 0
+
+
+static DEFINE_SPINLOCK(vmap_area_lock);
+static DEFINE_SPINLOCK(free_vmap_area_lock);
+/* Export for kexec only */
+LIST_HEAD(vmap_area_list);
+static struct rb_root vmap_area_root = RB_ROOT;
+static bool vmap_initialized __read_mostly;
+
+static struct rb_root purge_vmap_area_root = RB_ROOT;
+static LIST_HEAD(purge_vmap_area_list);
+static DEFINE_SPINLOCK(purge_vmap_area_lock);
+
+/*
+ * This kmem_cache is used for vmap_area objects. Instead of
+ * allocating from slab we reuse an object from this cache to
+ * make things faster. Especially in "no edge" splitting of
+ * free block.
+ */
+static struct kmem_cache *vmap_area_cachep;
+
+/*
+ * This linked list is used in pair with free_vmap_area_root.
+ * It gives O(1) access to prev/next to perform fast coalescing.
+ */
+static LIST_HEAD(free_vmap_area_list);
+
+/*
+ * This augment red-black tree represents the free vmap space.
+ * All vmap_area objects in this tree are sorted by va->va_start
+ * address. It is used for allocation and merging when a vmap
+ * object is released.
+ *
+ * Each vmap_area node contains a maximum available free block
+ * of its sub-tree, right or left. Therefore it is possible to
+ * find a lowest match of free area.
+ */
+static struct rb_root free_vmap_area_root = RB_ROOT;
+
+/*
+ * Preload a CPU with one object for "no edge" split case. The
+ * aim is to get rid of allocations from the atomic context, thus
+ * to use more permissive allocation masks.
+ */
+static DEFINE_PER_CPU(struct vmap_area *, ne_fit_preload_node);
+
+static __always_inline unsigned long
+va_size(struct vmap_area *va)
+{
+	return (va->va_end - va->va_start);
+}
+
+static __always_inline unsigned long
+get_subtree_max_size(struct rb_node *node)
+{
+	struct vmap_area *va;
+
+	va = rb_entry_safe(node, struct vmap_area, rb_node);
+	return va ? va->subtree_max_size : 0;
+}
+
+RB_DECLARE_CALLBACKS_MAX(static, free_vmap_area_rb_augment_cb,
+	struct vmap_area, rb_node, unsigned long, subtree_max_size, va_size)
+
+static void reclaim_and_purge_vmap_areas(void);
+static BLOCKING_NOTIFIER_HEAD(vmap_notify_list);
+static void drain_vmap_area_work(struct work_struct *work);
+static DECLARE_WORK(drain_vmap_work, drain_vmap_area_work);
+
+static atomic_long_t nr_vmalloc_pages;
+
+unsigned long vmalloc_nr_pages(void)
+{
+	return atomic_long_read(&nr_vmalloc_pages);
+}
+
+/* Look up the first VA which satisfies addr < va_end, NULL if none. */
+static struct vmap_area *find_vmap_area_exceed_addr(unsigned long addr)
+{
+	struct vmap_area *va = NULL;
+	struct rb_node *n = vmap_area_root.rb_node;
+
+	addr = (unsigned long)kasan_reset_tag((void *)addr);
+
+	while (n) {
+		struct vmap_area *tmp;
+
+		tmp = rb_entry(n, struct vmap_area, rb_node);
+		if (tmp->va_end > addr) {
+			va = tmp;
+			if (tmp->va_start <= addr)
+				break;
+
+			n = n->rb_left;
+		} else
+			n = n->rb_right;
+	}
+
+	return va;
+}
+
+static struct vmap_area *__find_vmap_area(unsigned long addr, struct rb_root *root)
+{
+	struct rb_node *n = root->rb_node;
+
+	addr = (unsigned long)kasan_reset_tag((void *)addr);
+
+	while (n) {
+		struct vmap_area *va;
+
+		va = rb_entry(n, struct vmap_area, rb_node);
+		if (addr < va->va_start)
+			n = n->rb_left;
+		else if (addr >= va->va_end)
+			n = n->rb_right;
+		else
+			return va;
+	}
+
+	return NULL;
+}
+
+/*
+ * This function returns back addresses of parent node
+ * and its left or right link for further processing.
+ *
+ * Otherwise NULL is returned. In that case all further
+ * steps regarding inserting of conflicting overlap range
+ * have to be declined and actually considered as a bug.
+ */
+static __always_inline struct rb_node **
+find_va_links(struct vmap_area *va,
+	struct rb_root *root, struct rb_node *from,
+	struct rb_node **parent)
+{
+	struct vmap_area *tmp_va;
+	struct rb_node **link;
+
+	if (root) {
+		link = &root->rb_node;
+		if (unlikely(!*link)) {
+			*parent = NULL;
+			return link;
+		}
+	} else {
+		link = &from;
+	}
+
+	/*
+	 * Go to the bottom of the tree. When we hit the last point
+	 * we end up with parent rb_node and correct direction, i name
+	 * it link, where the new va->rb_node will be attached to.
+	 */
+	do {
+		tmp_va = rb_entry(*link, struct vmap_area, rb_node);
+
+		/*
+		 * During the traversal we also do some sanity check.
+		 * Trigger the BUG() if there are sides(left/right)
+		 * or full overlaps.
+		 */
+		if (va->va_end <= tmp_va->va_start)
+			link = &(*link)->rb_left;
+		else if (va->va_start >= tmp_va->va_end)
+			link = &(*link)->rb_right;
+		else {
+			WARN(1, "vmalloc bug: 0x%lx-0x%lx overlaps with 0x%lx-0x%lx\n",
+				va->va_start, va->va_end, tmp_va->va_start, tmp_va->va_end);
+
+			return NULL;
+		}
+	} while (*link);
+
+	*parent = &tmp_va->rb_node;
+	return link;
+}
+
+static __always_inline struct list_head *
+get_va_next_sibling(struct rb_node *parent, struct rb_node **link)
+{
+	struct list_head *list;
+
+	if (unlikely(!parent))
+		/*
+		 * The red-black tree where we try to find VA neighbors
+		 * before merging or inserting is empty, i.e. it means
+		 * there is no free vmap space. Normally it does not
+		 * happen but we handle this case anyway.
+		 */
+		return NULL;
+
+	list = &rb_entry(parent, struct vmap_area, rb_node)->list;
+	return (&parent->rb_right == link ? list->next : list);
+}
+
+static __always_inline void
+__link_va(struct vmap_area *va, struct rb_root *root,
+	struct rb_node *parent, struct rb_node **link,
+	struct list_head *head, bool augment)
+{
+	/*
+	 * VA is still not in the list, but we can
+	 * identify its future previous list_head node.
+	 */
+	if (likely(parent)) {
+		head = &rb_entry(parent, struct vmap_area, rb_node)->list;
+		if (&parent->rb_right != link)
+			head = head->prev;
+	}
+
+	/* Insert to the rb-tree */
+	rb_link_node(&va->rb_node, parent, link);
+	if (augment) {
+		/*
+		 * Some explanation here. Just perform simple insertion
+		 * to the tree. We do not set va->subtree_max_size to
+		 * its current size before calling rb_insert_augmented().
+		 * It is because we populate the tree from the bottom
+		 * to parent levels when the node _is_ in the tree.
+		 *
+		 * Therefore we set subtree_max_size to zero after insertion,
+		 * to let __augment_tree_propagate_from() puts everything to
+		 * the correct order later on.
+		 */
+		rb_insert_augmented(&va->rb_node,
+			root, &free_vmap_area_rb_augment_cb);
+		va->subtree_max_size = 0;
+	} else {
+		rb_insert_color(&va->rb_node, root);
+	}
+
+	/* Address-sort this list */
+	list_add(&va->list, head);
+}
+
+static __always_inline void
+link_va(struct vmap_area *va, struct rb_root *root,
+	struct rb_node *parent, struct rb_node **link,
+	struct list_head *head)
+{
+	__link_va(va, root, parent, link, head, false);
+}
+
+static __always_inline void
+link_va_augment(struct vmap_area *va, struct rb_root *root,
+	struct rb_node *parent, struct rb_node **link,
+	struct list_head *head)
+{
+	__link_va(va, root, parent, link, head, true);
+}
+
+static __always_inline void
+__unlink_va(struct vmap_area *va, struct rb_root *root, bool augment)
+{
+	if (WARN_ON(RB_EMPTY_NODE(&va->rb_node)))
+		return;
+
+	if (augment)
+		rb_erase_augmented(&va->rb_node,
+			root, &free_vmap_area_rb_augment_cb);
+	else
+		rb_erase(&va->rb_node, root);
+
+	list_del_init(&va->list);
+	RB_CLEAR_NODE(&va->rb_node);
+}
+
+static __always_inline void
+unlink_va(struct vmap_area *va, struct rb_root *root)
+{
+	__unlink_va(va, root, false);
+}
+
+static __always_inline void
+unlink_va_augment(struct vmap_area *va, struct rb_root *root)
+{
+	__unlink_va(va, root, true);
+}
+
+#if DEBUG_AUGMENT_PROPAGATE_CHECK
+/*
+ * Gets called when remove the node and rotate.
+ */
+static __always_inline unsigned long
+compute_subtree_max_size(struct vmap_area *va)
+{
+	return max3(va_size(va),
+		get_subtree_max_size(va->rb_node.rb_left),
+		get_subtree_max_size(va->rb_node.rb_right));
+}
+
+static void
+augment_tree_propagate_check(void)
+{
+	struct vmap_area *va;
+	unsigned long computed_size;
+
+	list_for_each_entry(va, &free_vmap_area_list, list) {
+		computed_size = compute_subtree_max_size(va);
+		if (computed_size != va->subtree_max_size)
+			pr_emerg("tree is corrupted: %lu, %lu\n",
+				va_size(va), va->subtree_max_size);
+	}
+}
+#endif
+
+/*
+ * This function populates subtree_max_size from bottom to upper
+ * levels starting from VA point. The propagation must be done
+ * when VA size is modified by changing its va_start/va_end. Or
+ * in case of newly inserting of VA to the tree.
+ *
+ * It means that __augment_tree_propagate_from() must be called:
+ * - After VA has been inserted to the tree(free path);
+ * - After VA has been shrunk(allocation path);
+ * - After VA has been increased(merging path).
+ *
+ * Please note that, it does not mean that upper parent nodes
+ * and their subtree_max_size are recalculated all the time up
+ * to the root node.
+ *
+ *       4--8
+ *        /\
+ *       /  \
+ *      /    \
+ *    2--2  8--8
+ *
+ * For example if we modify the node 4, shrinking it to 2, then
+ * no any modification is required. If we shrink the node 2 to 1
+ * its subtree_max_size is updated only, and set to 1. If we shrink
+ * the node 8 to 6, then its subtree_max_size is set to 6 and parent
+ * node becomes 4--6.
+ */
+static __always_inline void
+augment_tree_propagate_from(struct vmap_area *va)
+{
+	/*
+	 * Populate the tree from bottom towards the root until
+	 * the calculated maximum available size of checked node
+	 * is equal to its current one.
+	 */
+	free_vmap_area_rb_augment_cb_propagate(&va->rb_node, NULL);
+
+#if DEBUG_AUGMENT_PROPAGATE_CHECK
+	augment_tree_propagate_check();
+#endif
+}
+
+static void
+insert_vmap_area(struct vmap_area *va,
+	struct rb_root *root, struct list_head *head)
+{
+	struct rb_node **link;
+	struct rb_node *parent;
+
+	link = find_va_links(va, root, NULL, &parent);
+	if (link)
+		link_va(va, root, parent, link, head);
+}
+
+static void
+insert_vmap_area_augment(struct vmap_area *va,
+	struct rb_node *from, struct rb_root *root,
+	struct list_head *head)
+{
+	struct rb_node **link;
+	struct rb_node *parent;
+
+	if (from)
+		link = find_va_links(va, NULL, from, &parent);
+	else
+		link = find_va_links(va, root, NULL, &parent);
+
+	if (link) {
+		link_va_augment(va, root, parent, link, head);
+		augment_tree_propagate_from(va);
+	}
+}
+
+/*
+ * Merge de-allocated chunk of VA memory with previous
+ * and next free blocks. If coalesce is not done a new
+ * free area is inserted. If VA has been merged, it is
+ * freed.
+ *
+ * Please note, it can return NULL in case of overlap
+ * ranges, followed by WARN() report. Despite it is a
+ * buggy behaviour, a system can be alive and keep
+ * ongoing.
+ */
+static __always_inline struct vmap_area *
+__merge_or_add_vmap_area(struct vmap_area *va,
+	struct rb_root *root, struct list_head *head, bool augment)
+{
+	struct vmap_area *sibling;
+	struct list_head *next;
+	struct rb_node **link;
+	struct rb_node *parent;
+	bool merged = false;
+
+	/*
+	 * Find a place in the tree where VA potentially will be
+	 * inserted, unless it is merged with its sibling/siblings.
+	 */
+	link = find_va_links(va, root, NULL, &parent);
+	if (!link)
+		return NULL;
+
+	/*
+	 * Get next node of VA to check if merging can be done.
+	 */
+	next = get_va_next_sibling(parent, link);
+	if (unlikely(next == NULL))
+		goto insert;
+
+	/*
+	 * start            end
+	 * |                |
+	 * |<------VA------>|<-----Next----->|
+	 *                  |                |
+	 *                  start            end
+	 */
+	if (next != head) {
+		sibling = list_entry(next, struct vmap_area, list);
+		if (sibling->va_start == va->va_end) {
+			sibling->va_start = va->va_start;
+
+			/* Free vmap_area object. */
+			kmem_cache_free(vmap_area_cachep, va);
+
+			/* Point to the new merged area. */
+			va = sibling;
+			merged = true;
+		}
+	}
+
+	/*
+	 * start            end
+	 * |                |
+	 * |<-----Prev----->|<------VA------>|
+	 *                  |                |
+	 *                  start            end
+	 */
+	if (next->prev != head) {
+		sibling = list_entry(next->prev, struct vmap_area, list);
+		if (sibling->va_end == va->va_start) {
+			/*
+			 * If both neighbors are coalesced, it is important
+			 * to unlink the "next" node first, followed by merging
+			 * with "previous" one. Otherwise the tree might not be
+			 * fully populated if a sibling's augmented value is
+			 * "normalized" because of rotation operations.
+			 */
+			if (merged)
+				__unlink_va(va, root, augment);
+
+			sibling->va_end = va->va_end;
+
+			/* Free vmap_area object. */
+			kmem_cache_free(vmap_area_cachep, va);
+
+			/* Point to the new merged area. */
+			va = sibling;
+			merged = true;
+		}
+	}
+
+insert:
+	if (!merged)
+		__link_va(va, root, parent, link, head, augment);
+
+	return va;
+}
+
+static __always_inline struct vmap_area *
+merge_or_add_vmap_area(struct vmap_area *va,
+	struct rb_root *root, struct list_head *head)
+{
+	return __merge_or_add_vmap_area(va, root, head, false);
+}
+
+static __always_inline struct vmap_area *
+merge_or_add_vmap_area_augment(struct vmap_area *va,
+	struct rb_root *root, struct list_head *head)
+{
+	va = __merge_or_add_vmap_area(va, root, head, true);
+	if (va)
+		augment_tree_propagate_from(va);
+
+	return va;
+}
+
+static __always_inline bool
+is_within_this_va(struct vmap_area *va, unsigned long size,
+	unsigned long align, unsigned long vstart)
+{
+	unsigned long nva_start_addr;
+
+	if (va->va_start > vstart)
+		nva_start_addr = ALIGN(va->va_start, align);
+	else
+		nva_start_addr = ALIGN(vstart, align);
+
+	/* Can be overflowed due to big size or alignment. */
+	if (nva_start_addr + size < nva_start_addr ||
+			nva_start_addr < vstart)
+		return false;
+
+	return (nva_start_addr + size <= va->va_end);
+}
+
+/*
+ * Find the first free block(lowest start address) in the tree,
+ * that will accomplish the request corresponding to passing
+ * parameters. Please note, with an alignment bigger than PAGE_SIZE,
+ * a search length is adjusted to account for worst case alignment
+ * overhead.
+ */
+static __always_inline struct vmap_area *
+find_vmap_lowest_match(struct rb_root *root, unsigned long size,
+	unsigned long align, unsigned long vstart, bool adjust_search_size)
+{
+	struct vmap_area *va;
+	struct rb_node *node;
+	unsigned long length;
+
+	/* Start from the root. */
+	node = root->rb_node;
+
+	/* Adjust the search size for alignment overhead. */
+	length = adjust_search_size ? size + align - 1 : size;
+
+	while (node) {
+		va = rb_entry(node, struct vmap_area, rb_node);
+
+		if (get_subtree_max_size(node->rb_left) >= length &&
+				vstart < va->va_start) {
+			node = node->rb_left;
+		} else {
+			if (is_within_this_va(va, size, align, vstart))
+				return va;
+
+			/*
+			 * Does not make sense to go deeper towards the right
+			 * sub-tree if it does not have a free block that is
+			 * equal or bigger to the requested search length.
+			 */
+			if (get_subtree_max_size(node->rb_right) >= length) {
+				node = node->rb_right;
+				continue;
+			}
+
+			/*
+			 * OK. We roll back and find the first right sub-tree,
+			 * that will satisfy the search criteria. It can happen
+			 * due to "vstart" restriction or an alignment overhead
+			 * that is bigger then PAGE_SIZE.
+			 */
+			while ((node = rb_parent(node))) {
+				va = rb_entry(node, struct vmap_area, rb_node);
+				if (is_within_this_va(va, size, align, vstart))
+					return va;
+
+				if (get_subtree_max_size(node->rb_right) >= length &&
+						vstart <= va->va_start) {
+					/*
+					 * Shift the vstart forward. Please note, we update it with
+					 * parent's start address adding "1" because we do not want
+					 * to enter same sub-tree after it has already been checked
+					 * and no suitable free block found there.
+					 */
+					vstart = va->va_start + 1;
+					node = node->rb_right;
+					break;
+				}
+			}
+		}
+	}
+
+	return NULL;
+}
+
+#if DEBUG_AUGMENT_LOWEST_MATCH_CHECK
+#include <linux/random.h>
+
+static struct vmap_area *
+find_vmap_lowest_linear_match(struct list_head *head, unsigned long size,
+	unsigned long align, unsigned long vstart)
+{
+	struct vmap_area *va;
+
+	list_for_each_entry(va, head, list) {
+		if (!is_within_this_va(va, size, align, vstart))
+			continue;
+
+		return va;
+	}
+
+	return NULL;
+}
+
+static void
+find_vmap_lowest_match_check(struct rb_root *root, struct list_head *head,
+			     unsigned long size, unsigned long align)
+{
+	struct vmap_area *va_1, *va_2;
+	unsigned long vstart;
+	unsigned int rnd;
+
+	get_random_bytes(&rnd, sizeof(rnd));
+	vstart = VMALLOC_START + rnd;
+
+	va_1 = find_vmap_lowest_match(root, size, align, vstart, false);
+	va_2 = find_vmap_lowest_linear_match(head, size, align, vstart);
+
+	if (va_1 != va_2)
+		pr_emerg("not lowest: t: 0x%p, l: 0x%p, v: 0x%lx\n",
+			va_1, va_2, vstart);
+}
+#endif
+
+enum fit_type {
+	NOTHING_FIT = 0,
+	FL_FIT_TYPE = 1,	/* full fit */
+	LE_FIT_TYPE = 2,	/* left edge fit */
+	RE_FIT_TYPE = 3,	/* right edge fit */
+	NE_FIT_TYPE = 4		/* no edge fit */
+};
+
+static __always_inline enum fit_type
+classify_va_fit_type(struct vmap_area *va,
+	unsigned long nva_start_addr, unsigned long size)
+{
+	enum fit_type type;
+
+	/* Check if it is within VA. */
+	if (nva_start_addr < va->va_start ||
+			nva_start_addr + size > va->va_end)
+		return NOTHING_FIT;
+
+	/* Now classify. */
+	if (va->va_start == nva_start_addr) {
+		if (va->va_end == nva_start_addr + size)
+			type = FL_FIT_TYPE;
+		else
+			type = LE_FIT_TYPE;
+	} else if (va->va_end == nva_start_addr + size) {
+		type = RE_FIT_TYPE;
+	} else {
+		type = NE_FIT_TYPE;
+	}
+
+	return type;
+}
+
+static __always_inline int
+adjust_va_to_fit_type(struct rb_root *root, struct list_head *head,
+		      struct vmap_area *va, unsigned long nva_start_addr,
+		      unsigned long size)
+{
+	struct vmap_area *lva = NULL;
+	enum fit_type type = classify_va_fit_type(va, nva_start_addr, size);
+
+	if (type == FL_FIT_TYPE) {
+		/*
+		 * No need to split VA, it fully fits.
+		 *
+		 * |               |
+		 * V      NVA      V
+		 * |---------------|
+		 */
+		unlink_va_augment(va, root);
+		kmem_cache_free(vmap_area_cachep, va);
+	} else if (type == LE_FIT_TYPE) {
+		/*
+		 * Split left edge of fit VA.
+		 *
+		 * |       |
+		 * V  NVA  V   R
+		 * |-------|-------|
+		 */
+		va->va_start += size;
+	} else if (type == RE_FIT_TYPE) {
+		/*
+		 * Split right edge of fit VA.
+		 *
+		 *         |       |
+		 *     L   V  NVA  V
+		 * |-------|-------|
+		 */
+		va->va_end = nva_start_addr;
+	} else if (type == NE_FIT_TYPE) {
+		/*
+		 * Split no edge of fit VA.
+		 *
+		 *     |       |
+		 *   L V  NVA  V R
+		 * |---|-------|---|
+		 */
+		lva = __this_cpu_xchg(ne_fit_preload_node, NULL);
+		if (unlikely(!lva)) {
+			/*
+			 * For percpu allocator we do not do any pre-allocation
+			 * and leave it as it is. The reason is it most likely
+			 * never ends up with NE_FIT_TYPE splitting. In case of
+			 * percpu allocations offsets and sizes are aligned to
+			 * fixed align request, i.e. RE_FIT_TYPE and FL_FIT_TYPE
+			 * are its main fitting cases.
+			 *
+			 * There are a few exceptions though, as an example it is
+			 * a first allocation (early boot up) when we have "one"
+			 * big free space that has to be split.
+			 *
+			 * Also we can hit this path in case of regular "vmap"
+			 * allocations, if "this" current CPU was not preloaded.
+			 * See the comment in alloc_vmap_area() why. If so, then
+			 * GFP_NOWAIT is used instead to get an extra object for
+			 * split purpose. That is rare and most time does not
+			 * occur.
+			 *
+			 * What happens if an allocation gets failed. Basically,
+			 * an "overflow" path is triggered to purge lazily freed
+			 * areas to free some memory, then, the "retry" path is
+			 * triggered to repeat one more time. See more details
+			 * in alloc_vmap_area() function.
+			 */
+			lva = kmem_cache_alloc(vmap_area_cachep, GFP_NOWAIT);
+			if (!lva)
+				return -1;
+		}
+
+		/*
+		 * Build the remainder.
+		 */
+		lva->va_start = va->va_start;
+		lva->va_end = nva_start_addr;
+
+		/*
+		 * Shrink this VA to remaining size.
+		 */
+		va->va_start = nva_start_addr + size;
+	} else {
+		return -1;
+	}
+
+	if (type != FL_FIT_TYPE) {
+		augment_tree_propagate_from(va);
+
+		if (lva)	/* type == NE_FIT_TYPE */
+			insert_vmap_area_augment(lva, &va->rb_node, root, head);
+	}
+
+	return 0;
+}
+
+/*
+ * Returns a start address of the newly allocated area, if success.
+ * Otherwise a vend is returned that indicates failure.
+ */
+static __always_inline unsigned long
+__alloc_vmap_area(struct rb_root *root, struct list_head *head,
+	unsigned long size, unsigned long align,
+	unsigned long vstart, unsigned long vend)
+{
+	bool adjust_search_size = true;
+	unsigned long nva_start_addr;
+	struct vmap_area *va;
+	int ret;
+
+	/*
+	 * Do not adjust when:
+	 *   a) align <= PAGE_SIZE, because it does not make any sense.
+	 *      All blocks(their start addresses) are at least PAGE_SIZE
+	 *      aligned anyway;
+	 *   b) a short range where a requested size corresponds to exactly
+	 *      specified [vstart:vend] interval and an alignment > PAGE_SIZE.
+	 *      With adjusted search length an allocation would not succeed.
+	 */
+	if (align <= PAGE_SIZE || (align > PAGE_SIZE && (vend - vstart) == size))
+		adjust_search_size = false;
+
+	va = find_vmap_lowest_match(root, size, align, vstart, adjust_search_size);
+	if (unlikely(!va))
+		return vend;
+
+	if (va->va_start > vstart)
+		nva_start_addr = ALIGN(va->va_start, align);
+	else
+		nva_start_addr = ALIGN(vstart, align);
+
+	/* Check the "vend" restriction. */
+	if (nva_start_addr + size > vend)
+		return vend;
+
+	/* Update the free vmap_area. */
+	ret = adjust_va_to_fit_type(root, head, va, nva_start_addr, size);
+	if (WARN_ON_ONCE(ret))
+		return vend;
+
+#if DEBUG_AUGMENT_LOWEST_MATCH_CHECK
+	find_vmap_lowest_match_check(root, head, size, align);
+#endif
+
+	return nva_start_addr;
+}
+
+/*
+ * Free a region of KVA allocated by alloc_vmap_area
+ */
+static void free_vmap_area(struct vmap_area *va)
+{
+	/*
+	 * Remove from the busy tree/list.
+	 */
+	spin_lock(&vmap_area_lock);
+	unlink_va(va, &vmap_area_root);
+	spin_unlock(&vmap_area_lock);
+
+	/*
+	 * Insert/Merge it back to the free tree/list.
+	 */
+	spin_lock(&free_vmap_area_lock);
+	merge_or_add_vmap_area_augment(va, &free_vmap_area_root, &free_vmap_area_list);
+	spin_unlock(&free_vmap_area_lock);
+}
+
+static inline void
+preload_this_cpu_lock(spinlock_t *lock, gfp_t gfp_mask, int node)
+{
+	struct vmap_area *va = NULL;
+
+	/*
+	 * Preload this CPU with one extra vmap_area object. It is used
+	 * when fit type of free area is NE_FIT_TYPE. It guarantees that
+	 * a CPU that does an allocation is preloaded.
+	 *
+	 * We do it in non-atomic context, thus it allows us to use more
+	 * permissive allocation masks to be more stable under low memory
+	 * condition and high memory pressure.
+	 */
+	if (!this_cpu_read(ne_fit_preload_node))
+		va = kmem_cache_alloc_node(vmap_area_cachep, gfp_mask, node);
+
+	spin_lock(lock);
+
+	if (va && __this_cpu_cmpxchg(ne_fit_preload_node, NULL, va))
+		kmem_cache_free(vmap_area_cachep, va);
+}
+
+/*
+ * Allocate a region of KVA of the specified size and alignment, within the
+ * vstart and vend.
+ */
+static struct vmap_area *alloc_vmap_area(unsigned long size,
+				unsigned long align,
+				unsigned long vstart, unsigned long vend,
+				int node, gfp_t gfp_mask,
+				unsigned long va_flags)
+{
+	struct vmap_area *va;
+	unsigned long freed;
+	unsigned long addr;
+	int purged = 0;
+	int ret;
+
+	if (unlikely(!size || offset_in_page(size) || !is_power_of_2(align)))
+		return ERR_PTR(-EINVAL);
+
+	if (unlikely(!vmap_initialized))
+		return ERR_PTR(-EBUSY);
+
+	might_sleep();
+	gfp_mask = gfp_mask & GFP_RECLAIM_MASK;
+
+	va = kmem_cache_alloc_node(vmap_area_cachep, gfp_mask, node);
+	if (unlikely(!va))
+		return ERR_PTR(-ENOMEM);
+
+	/*
+	 * Only scan the relevant parts containing pointers to other objects
+	 * to avoid false negatives.
+	 */
+	kmemleak_scan_area(&va->rb_node, SIZE_MAX, gfp_mask);
+
+retry:
+	preload_this_cpu_lock(&free_vmap_area_lock, gfp_mask, node);
+	addr = __alloc_vmap_area(&free_vmap_area_root, &free_vmap_area_list,
+		size, align, vstart, vend);
+	spin_unlock(&free_vmap_area_lock);
+
+	trace_alloc_vmap_area(addr, size, align, vstart, vend, addr == vend);
+
+	/*
+	 * If an allocation fails, the "vend" address is
+	 * returned. Therefore trigger the overflow path.
+	 */
+	if (unlikely(addr == vend))
+		goto overflow;
+
+	va->va_start = addr;
+	va->va_end = addr + size;
+	va->vm = NULL;
+	va->flags = va_flags;
+
+	spin_lock(&vmap_area_lock);
+	insert_vmap_area(va, &vmap_area_root, &vmap_area_list);
+	spin_unlock(&vmap_area_lock);
+
+	BUG_ON(!IS_ALIGNED(va->va_start, align));
+	BUG_ON(va->va_start < vstart);
+	BUG_ON(va->va_end > vend);
+
+	ret = kasan_populate_vmalloc(addr, size);
+	if (ret) {
+		free_vmap_area(va);
+		return ERR_PTR(ret);
+	}
+
+	return va;
+
+overflow:
+	if (!purged) {
+		reclaim_and_purge_vmap_areas();
+		purged = 1;
+		goto retry;
+	}
+
+	freed = 0;
+	blocking_notifier_call_chain(&vmap_notify_list, 0, &freed);
+
+	if (freed > 0) {
+		purged = 0;
+		goto retry;
+	}
+
+	if (!(gfp_mask & __GFP_NOWARN) && printk_ratelimit())
+		pr_warn("vmap allocation for size %lu failed: use vmalloc=<size> to increase size\n",
+			size);
+
+	kmem_cache_free(vmap_area_cachep, va);
+	return ERR_PTR(-EBUSY);
+}
+
+int register_vmap_purge_notifier(struct notifier_block *nb)
+{
+	return blocking_notifier_chain_register(&vmap_notify_list, nb);
+}
+EXPORT_SYMBOL_GPL(register_vmap_purge_notifier);
+
+int unregister_vmap_purge_notifier(struct notifier_block *nb)
+{
+	return blocking_notifier_chain_unregister(&vmap_notify_list, nb);
+}
+EXPORT_SYMBOL_GPL(unregister_vmap_purge_notifier);
+
+/*
+ * lazy_max_pages is the maximum amount of virtual address space we gather up
+ * before attempting to purge with a TLB flush.
+ *
+ * There is a tradeoff here: a larger number will cover more kernel page tables
+ * and take slightly longer to purge, but it will linearly reduce the number of
+ * global TLB flushes that must be performed. It would seem natural to scale
+ * this number up linearly with the number of CPUs (because vmapping activity
+ * could also scale linearly with the number of CPUs), however it is likely
+ * that in practice, workloads might be constrained in other ways that mean
+ * vmap activity will not scale linearly with CPUs. Also, I want to be
+ * conservative and not introduce a big latency on huge systems, so go with
+ * a less aggressive log scale. It will still be an improvement over the old
+ * code, and it will be simple to change the scale factor if we find that it
+ * becomes a problem on bigger systems.
+ */
+static unsigned long lazy_max_pages(void)
+{
+	unsigned int log;
+
+	log = fls(num_online_cpus());
+
+	return log * (32UL * 1024 * 1024 / PAGE_SIZE);
+}
+
+static atomic_long_t vmap_lazy_nr = ATOMIC_LONG_INIT(0);
+
+/*
+ * Serialize vmap purging.  There is no actual critical section protected
+ * by this lock, but we want to avoid concurrent calls for performance
+ * reasons and to make the pcpu_get_vm_areas more deterministic.
+ */
+static DEFINE_MUTEX(vmap_purge_lock);
+
+/* for per-CPU blocks */
+static void purge_fragmented_blocks_allcpus(void);
+
+/*
+ * Purges all lazily-freed vmap areas.
+ */
+static bool __purge_vmap_area_lazy(unsigned long start, unsigned long end)
+{
+	unsigned long resched_threshold;
+	unsigned int num_purged_areas = 0;
+	struct list_head local_purge_list;
+	struct vmap_area *va, *n_va;
+
+	lockdep_assert_held(&vmap_purge_lock);
+
+	spin_lock(&purge_vmap_area_lock);
+	purge_vmap_area_root = RB_ROOT;
+	list_replace_init(&purge_vmap_area_list, &local_purge_list);
+	spin_unlock(&purge_vmap_area_lock);
+
+	if (unlikely(list_empty(&local_purge_list)))
+		goto out;
+
+	start = min(start,
+		list_first_entry(&local_purge_list,
+			struct vmap_area, list)->va_start);
+
+	end = max(end,
+		list_last_entry(&local_purge_list,
+			struct vmap_area, list)->va_end);
+
+	flush_tlb_kernel_range(start, end);
+	resched_threshold = lazy_max_pages() << 1;
+
+	spin_lock(&free_vmap_area_lock);
+	list_for_each_entry_safe(va, n_va, &local_purge_list, list) {
+		unsigned long nr = (va->va_end - va->va_start) >> PAGE_SHIFT;
+		unsigned long orig_start = va->va_start;
+		unsigned long orig_end = va->va_end;
+
+		/*
+		 * Finally insert or merge lazily-freed area. It is
+		 * detached and there is no need to "unlink" it from
+		 * anything.
+		 */
+		va = merge_or_add_vmap_area_augment(va, &free_vmap_area_root,
+				&free_vmap_area_list);
+
+		if (!va)
+			continue;
+
+		if (is_vmalloc_or_module_addr((void *)orig_start))
+			kasan_release_vmalloc(orig_start, orig_end,
+					      va->va_start, va->va_end);
+
+		atomic_long_sub(nr, &vmap_lazy_nr);
+		num_purged_areas++;
+
+		if (atomic_long_read(&vmap_lazy_nr) < resched_threshold)
+			cond_resched_lock(&free_vmap_area_lock);
+	}
+	spin_unlock(&free_vmap_area_lock);
+
+out:
+	trace_purge_vmap_area_lazy(start, end, num_purged_areas);
+	return num_purged_areas > 0;
+}
+
+/*
+ * Reclaim vmap areas by purging fragmented blocks and purge_vmap_area_list.
+ */
+static void reclaim_and_purge_vmap_areas(void)
+
+{
+	mutex_lock(&vmap_purge_lock);
+	purge_fragmented_blocks_allcpus();
+	__purge_vmap_area_lazy(ULONG_MAX, 0);
+	mutex_unlock(&vmap_purge_lock);
+}
+
+static void drain_vmap_area_work(struct work_struct *work)
+{
+	unsigned long nr_lazy;
+
+	do {
+		mutex_lock(&vmap_purge_lock);
+		__purge_vmap_area_lazy(ULONG_MAX, 0);
+		mutex_unlock(&vmap_purge_lock);
+
+		/* Recheck if further work is required. */
+		nr_lazy = atomic_long_read(&vmap_lazy_nr);
+	} while (nr_lazy > lazy_max_pages());
+}
+
+/*
+ * Free a vmap area, caller ensuring that the area has been unmapped,
+ * unlinked and flush_cache_vunmap had been called for the correct
+ * range previously.
+ */
+static void free_vmap_area_noflush(struct vmap_area *va)
+{
+	unsigned long nr_lazy_max = lazy_max_pages();
+	unsigned long va_start = va->va_start;
+	unsigned long nr_lazy;
+
+	if (WARN_ON_ONCE(!list_empty(&va->list)))
+		return;
+
+	nr_lazy = atomic_long_add_return((va->va_end - va->va_start) >>
+				PAGE_SHIFT, &vmap_lazy_nr);
+
+	/*
+	 * Merge or place it to the purge tree/list.
+	 */
+	spin_lock(&purge_vmap_area_lock);
+	merge_or_add_vmap_area(va,
+		&purge_vmap_area_root, &purge_vmap_area_list);
+	spin_unlock(&purge_vmap_area_lock);
+
+	trace_free_vmap_area_noflush(va_start, nr_lazy, nr_lazy_max);
+
+	/* After this point, we may free va at any time */
+	if (unlikely(nr_lazy > nr_lazy_max))
+		schedule_work(&drain_vmap_work);
+}
+
+/*
+ * Free and unmap a vmap area
+ */
+static void free_unmap_vmap_area(struct vmap_area *va)
+{
+	flush_cache_vunmap(va->va_start, va->va_end);
+	vunmap_range_noflush(va->va_start, va->va_end);
+	if (debug_pagealloc_enabled_static())
+		flush_tlb_kernel_range(va->va_start, va->va_end);
+
+	free_vmap_area_noflush(va);
+}
+
+struct vmap_area *find_vmap_area(unsigned long addr)
+{
+	struct vmap_area *va;
+
+	spin_lock(&vmap_area_lock);
+	va = __find_vmap_area(addr, &vmap_area_root);
+	spin_unlock(&vmap_area_lock);
+
+	return va;
+}
+
+static struct vmap_area *find_unlink_vmap_area(unsigned long addr)
+{
+	struct vmap_area *va;
+
+	spin_lock(&vmap_area_lock);
+	va = __find_vmap_area(addr, &vmap_area_root);
+	if (va)
+		unlink_va(va, &vmap_area_root);
+	spin_unlock(&vmap_area_lock);
+
+	return va;
+}
+
+/*** Per cpu kva allocator ***/
+
+/*
+ * vmap space is limited especially on 32 bit architectures. Ensure there is
+ * room for at least 16 percpu vmap blocks per CPU.
+ */
+/*
+ * If we had a constant VMALLOC_START and VMALLOC_END, we'd like to be able
+ * to #define VMALLOC_SPACE		(VMALLOC_END-VMALLOC_START). Guess
+ * instead (we just need a rough idea)
+ */
+#if BITS_PER_LONG == 32
+#define VMALLOC_SPACE		(128UL*1024*1024)
+#else
+#define VMALLOC_SPACE		(128UL*1024*1024*1024)
+#endif
+
+#define VMALLOC_PAGES		(VMALLOC_SPACE / PAGE_SIZE)
+#define VMAP_MAX_ALLOC		BITS_PER_LONG	/* 256K with 4K pages */
+#define VMAP_BBMAP_BITS_MAX	1024	/* 4MB with 4K pages */
+#define VMAP_BBMAP_BITS_MIN	(VMAP_MAX_ALLOC*2)
+#define VMAP_MIN(x, y)		((x) < (y) ? (x) : (y)) /* can't use min() */
+#define VMAP_MAX(x, y)		((x) > (y) ? (x) : (y)) /* can't use max() */
+#define VMAP_BBMAP_BITS		\
+		VMAP_MIN(VMAP_BBMAP_BITS_MAX,	\
+		VMAP_MAX(VMAP_BBMAP_BITS_MIN,	\
+			VMALLOC_PAGES / roundup_pow_of_two(NR_CPUS) / 16))
+
+#define VMAP_BLOCK_SIZE		(VMAP_BBMAP_BITS * PAGE_SIZE)
+
+/*
+ * Purge threshold to prevent overeager purging of fragmented blocks for
+ * regular operations: Purge if vb->free is less than 1/4 of the capacity.
+ */
+#define VMAP_PURGE_THRESHOLD	(VMAP_BBMAP_BITS / 4)
+
+#define VMAP_RAM		0x1 /* indicates vm_map_ram area*/
+#define VMAP_BLOCK		0x2 /* mark out the vmap_block sub-type*/
+#define VMAP_FLAGS_MASK		0x3
+
+struct vmap_block_queue {
+	spinlock_t lock;
+	struct list_head free;
+
+	/*
+	 * An xarray requires an extra memory dynamically to
+	 * be allocated. If it is an issue, we can use rb-tree
+	 * instead.
+	 */
+	struct xarray vmap_blocks;
+};
+
+struct vmap_block {
+	spinlock_t lock;
+	struct vmap_area *va;
+	unsigned long free, dirty;
+	DECLARE_BITMAP(used_map, VMAP_BBMAP_BITS);
+	unsigned long dirty_min, dirty_max; /*< dirty range */
+	struct list_head free_list;
+	struct rcu_head rcu_head;
+	struct list_head purge;
+};
+
+/* Queue of free and dirty vmap blocks, for allocation and flushing purposes */
+static DEFINE_PER_CPU(struct vmap_block_queue, vmap_block_queue);
+
+/*
+ * In order to fast access to any "vmap_block" associated with a
+ * specific address, we use a hash.
+ *
+ * A per-cpu vmap_block_queue is used in both ways, to serialize
+ * an access to free block chains among CPUs(alloc path) and it
+ * also acts as a vmap_block hash(alloc/free paths). It means we
+ * overload it, since we already have the per-cpu array which is
+ * used as a hash table. When used as a hash a 'cpu' passed to
+ * per_cpu() is not actually a CPU but rather a hash index.
+ *
+ * A hash function is addr_to_vb_xa() which hashes any address
+ * to a specific index(in a hash) it belongs to. This then uses a
+ * per_cpu() macro to access an array with generated index.
+ *
+ * An example:
+ *
+ *  CPU_1  CPU_2  CPU_0
+ *    |      |      |
+ *    V      V      V
+ * 0     10     20     30     40     50     60
+ * |------|------|------|------|------|------|...<vmap address space>
+ *   CPU0   CPU1   CPU2   CPU0   CPU1   CPU2
+ *
+ * - CPU_1 invokes vm_unmap_ram(6), 6 belongs to CPU0 zone, thus
+ *   it access: CPU0/INDEX0 -> vmap_blocks -> xa_lock;
+ *
+ * - CPU_2 invokes vm_unmap_ram(11), 11 belongs to CPU1 zone, thus
+ *   it access: CPU1/INDEX1 -> vmap_blocks -> xa_lock;
+ *
+ * - CPU_0 invokes vm_unmap_ram(20), 20 belongs to CPU2 zone, thus
+ *   it access: CPU2/INDEX2 -> vmap_blocks -> xa_lock.
+ *
+ * This technique almost always avoids lock contention on insert/remove,
+ * however xarray spinlocks protect against any contention that remains.
+ */
+static struct xarray *
+addr_to_vb_xa(unsigned long addr)
+{
+	int index = (addr / VMAP_BLOCK_SIZE) % num_possible_cpus();
+
+	return &per_cpu(vmap_block_queue, index).vmap_blocks;
+}
+
+/*
+ * We should probably have a fallback mechanism to allocate virtual memory
+ * out of partially filled vmap blocks. However vmap block sizing should be
+ * fairly reasonable according to the vmalloc size, so it shouldn't be a
+ * big problem.
+ */
+
+static unsigned long addr_to_vb_idx(unsigned long addr)
+{
+	addr -= VMALLOC_START & ~(VMAP_BLOCK_SIZE-1);
+	addr /= VMAP_BLOCK_SIZE;
+	return addr;
+}
+
+static void *vmap_block_vaddr(unsigned long va_start, unsigned long pages_off)
+{
+	unsigned long addr;
+
+	addr = va_start + (pages_off << PAGE_SHIFT);
+	BUG_ON(addr_to_vb_idx(addr) != addr_to_vb_idx(va_start));
+	return (void *)addr;
+}
+
+/**
+ * new_vmap_block - allocates new vmap_block and occupies 2^order pages in this
+ *                  block. Of course pages number can't exceed VMAP_BBMAP_BITS
+ * @order:    how many 2^order pages should be occupied in newly allocated block
+ * @gfp_mask: flags for the page level allocator
+ *
+ * Return: virtual address in a newly allocated block or ERR_PTR(-errno)
+ */
+static void *new_vmap_block(unsigned int order, gfp_t gfp_mask)
+{
+	struct vmap_block_queue *vbq;
+	struct vmap_block *vb;
+	struct vmap_area *va;
+	struct xarray *xa;
+	unsigned long vb_idx;
+	int node, err;
+	void *vaddr;
+
+	node = numa_node_id();
+
+	vb = kmalloc_node(sizeof(struct vmap_block),
+			gfp_mask & GFP_RECLAIM_MASK, node);
+	if (unlikely(!vb))
+		return ERR_PTR(-ENOMEM);
+
+	va = alloc_vmap_area(VMAP_BLOCK_SIZE, VMAP_BLOCK_SIZE,
+					VMALLOC_START, VMALLOC_END,
+					node, gfp_mask,
+					VMAP_RAM|VMAP_BLOCK);
+	if (IS_ERR(va)) {
+		kfree(vb);
+		return ERR_CAST(va);
+	}
+
+	vaddr = vmap_block_vaddr(va->va_start, 0);
+	spin_lock_init(&vb->lock);
+	vb->va = va;
+	/* At least something should be left free */
+	BUG_ON(VMAP_BBMAP_BITS <= (1UL << order));
+	bitmap_zero(vb->used_map, VMAP_BBMAP_BITS);
+	vb->free = VMAP_BBMAP_BITS - (1UL << order);
+	vb->dirty = 0;
+	vb->dirty_min = VMAP_BBMAP_BITS;
+	vb->dirty_max = 0;
+	bitmap_set(vb->used_map, 0, (1UL << order));
+	INIT_LIST_HEAD(&vb->free_list);
+
+	xa = addr_to_vb_xa(va->va_start);
+	vb_idx = addr_to_vb_idx(va->va_start);
+	err = xa_insert(xa, vb_idx, vb, gfp_mask);
+	if (err) {
+		kfree(vb);
+		free_vmap_area(va);
+		return ERR_PTR(err);
+	}
+
+	vbq = raw_cpu_ptr(&vmap_block_queue);
+	spin_lock(&vbq->lock);
+	list_add_tail_rcu(&vb->free_list, &vbq->free);
+	spin_unlock(&vbq->lock);
+
+	return vaddr;
+}
+
+static void free_vmap_block(struct vmap_block *vb)
+{
+	struct vmap_block *tmp;
+	struct xarray *xa;
+
+	xa = addr_to_vb_xa(vb->va->va_start);
+	tmp = xa_erase(xa, addr_to_vb_idx(vb->va->va_start));
+	BUG_ON(tmp != vb);
+
+	spin_lock(&vmap_area_lock);
+	unlink_va(vb->va, &vmap_area_root);
+	spin_unlock(&vmap_area_lock);
+
+	free_vmap_area_noflush(vb->va);
+	kfree_rcu(vb, rcu_head);
+}
+
+static bool purge_fragmented_block(struct vmap_block *vb,
+		struct vmap_block_queue *vbq, struct list_head *purge_list,
+		bool force_purge)
+{
+	if (vb->free + vb->dirty != VMAP_BBMAP_BITS ||
+	    vb->dirty == VMAP_BBMAP_BITS)
+		return false;
+
+	/* Don't overeagerly purge usable blocks unless requested */
+	if (!(force_purge || vb->free < VMAP_PURGE_THRESHOLD))
+		return false;
+
+	/* prevent further allocs after releasing lock */
+	WRITE_ONCE(vb->free, 0);
+	/* prevent purging it again */
+	WRITE_ONCE(vb->dirty, VMAP_BBMAP_BITS);
+	vb->dirty_min = 0;
+	vb->dirty_max = VMAP_BBMAP_BITS;
+	spin_lock(&vbq->lock);
+	list_del_rcu(&vb->free_list);
+	spin_unlock(&vbq->lock);
+	list_add_tail(&vb->purge, purge_list);
+	return true;
+}
+
+static void free_purged_blocks(struct list_head *purge_list)
+{
+	struct vmap_block *vb, *n_vb;
+
+	list_for_each_entry_safe(vb, n_vb, purge_list, purge) {
+		list_del(&vb->purge);
+		free_vmap_block(vb);
+	}
+}
+
+static void purge_fragmented_blocks(int cpu)
+{
+	LIST_HEAD(purge);
+	struct vmap_block *vb;
+	struct vmap_block_queue *vbq = &per_cpu(vmap_block_queue, cpu);
+
+	rcu_read_lock();
+	list_for_each_entry_rcu(vb, &vbq->free, free_list) {
+		unsigned long free = READ_ONCE(vb->free);
+		unsigned long dirty = READ_ONCE(vb->dirty);
+
+		if (free + dirty != VMAP_BBMAP_BITS ||
+		    dirty == VMAP_BBMAP_BITS)
+			continue;
+
+		spin_lock(&vb->lock);
+		purge_fragmented_block(vb, vbq, &purge, true);
+		spin_unlock(&vb->lock);
+	}
+	rcu_read_unlock();
+	free_purged_blocks(&purge);
+}
+
+static void purge_fragmented_blocks_allcpus(void)
+{
+	int cpu;
+
+	for_each_possible_cpu(cpu)
+		purge_fragmented_blocks(cpu);
+}
+
+static void *vb_alloc(unsigned long size, gfp_t gfp_mask)
+{
+	struct vmap_block_queue *vbq;
+	struct vmap_block *vb;
+	void *vaddr = NULL;
+	unsigned int order;
+
+	BUG_ON(offset_in_page(size));
+	BUG_ON(size > PAGE_SIZE*VMAP_MAX_ALLOC);
+	if (WARN_ON(size == 0)) {
+		/*
+		 * Allocating 0 bytes isn't what caller wants since
+		 * get_order(0) returns funny result. Just warn and terminate
+		 * early.
+		 */
+		return NULL;
+	}
+	order = get_order(size);
+
+	rcu_read_lock();
+	vbq = raw_cpu_ptr(&vmap_block_queue);
+	list_for_each_entry_rcu(vb, &vbq->free, free_list) {
+		unsigned long pages_off;
+
+		if (READ_ONCE(vb->free) < (1UL << order))
+			continue;
+
+		spin_lock(&vb->lock);
+		if (vb->free < (1UL << order)) {
+			spin_unlock(&vb->lock);
+			continue;
+		}
+
+		pages_off = VMAP_BBMAP_BITS - vb->free;
+		vaddr = vmap_block_vaddr(vb->va->va_start, pages_off);
+		WRITE_ONCE(vb->free, vb->free - (1UL << order));
+		bitmap_set(vb->used_map, pages_off, (1UL << order));
+		if (vb->free == 0) {
+			spin_lock(&vbq->lock);
+			list_del_rcu(&vb->free_list);
+			spin_unlock(&vbq->lock);
+		}
+
+		spin_unlock(&vb->lock);
+		break;
+	}
+
+	rcu_read_unlock();
+
+	/* Allocate new block if nothing was found */
+	if (!vaddr)
+		vaddr = new_vmap_block(order, gfp_mask);
+
+	return vaddr;
+}
+
+static void vb_free(unsigned long addr, unsigned long size)
+{
+	unsigned long offset;
+	unsigned int order;
+	struct vmap_block *vb;
+	struct xarray *xa;
+
+	BUG_ON(offset_in_page(size));
+	BUG_ON(size > PAGE_SIZE*VMAP_MAX_ALLOC);
+
+	flush_cache_vunmap(addr, addr + size);
+
+	order = get_order(size);
+	offset = (addr & (VMAP_BLOCK_SIZE - 1)) >> PAGE_SHIFT;
+
+	xa = addr_to_vb_xa(addr);
+	vb = xa_load(xa, addr_to_vb_idx(addr));
+
+	spin_lock(&vb->lock);
+	bitmap_clear(vb->used_map, offset, (1UL << order));
+	spin_unlock(&vb->lock);
+
+	vunmap_range_noflush(addr, addr + size);
+
+	if (debug_pagealloc_enabled_static())
+		flush_tlb_kernel_range(addr, addr + size);
+
+	spin_lock(&vb->lock);
+
+	/* Expand the not yet TLB flushed dirty range */
+	vb->dirty_min = min(vb->dirty_min, offset);
+	vb->dirty_max = max(vb->dirty_max, offset + (1UL << order));
+
+	WRITE_ONCE(vb->dirty, vb->dirty + (1UL << order));
+	if (vb->dirty == VMAP_BBMAP_BITS) {
+		BUG_ON(vb->free);
+		spin_unlock(&vb->lock);
+		free_vmap_block(vb);
+	} else
+		spin_unlock(&vb->lock);
+}
+
+static void _vm_unmap_aliases(unsigned long start, unsigned long end, int flush)
+{
+	LIST_HEAD(purge_list);
+	int cpu;
+
+	if (unlikely(!vmap_initialized))
+		return;
+
+	mutex_lock(&vmap_purge_lock);
+
+	for_each_possible_cpu(cpu) {
+		struct vmap_block_queue *vbq = &per_cpu(vmap_block_queue, cpu);
+		struct vmap_block *vb;
+		unsigned long idx;
+
+		rcu_read_lock();
+		xa_for_each(&vbq->vmap_blocks, idx, vb) {
+			spin_lock(&vb->lock);
+
+			/*
+			 * Try to purge a fragmented block first. If it's
+			 * not purgeable, check whether there is dirty
+			 * space to be flushed.
+			 */
+			if (!purge_fragmented_block(vb, vbq, &purge_list, false) &&
+			    vb->dirty_max && vb->dirty != VMAP_BBMAP_BITS) {
+				unsigned long va_start = vb->va->va_start;
+				unsigned long s, e;
+
+				s = va_start + (vb->dirty_min << PAGE_SHIFT);
+				e = va_start + (vb->dirty_max << PAGE_SHIFT);
+
+				start = min(s, start);
+				end   = max(e, end);
+
+				/* Prevent that this is flushed again */
+				vb->dirty_min = VMAP_BBMAP_BITS;
+				vb->dirty_max = 0;
+
+				flush = 1;
+			}
+			spin_unlock(&vb->lock);
+		}
+		rcu_read_unlock();
+	}
+	free_purged_blocks(&purge_list);
+
+	if (!__purge_vmap_area_lazy(start, end) && flush)
+		flush_tlb_kernel_range(start, end);
+	mutex_unlock(&vmap_purge_lock);
+}
+
+/**
+ * vm_unmap_aliases - unmap outstanding lazy aliases in the vmap layer
+ *
+ * The vmap/vmalloc layer lazily flushes kernel virtual mappings primarily
+ * to amortize TLB flushing overheads. What this means is that any page you
+ * have now, may, in a former life, have been mapped into kernel virtual
+ * address by the vmap layer and so there might be some CPUs with TLB entries
+ * still referencing that page (additional to the regular 1:1 kernel mapping).
+ *
+ * vm_unmap_aliases flushes all such lazy mappings. After it returns, we can
+ * be sure that none of the pages we have control over will have any aliases
+ * from the vmap layer.
+ */
+void vm_unmap_aliases(void)
+{
+	unsigned long start = ULONG_MAX, end = 0;
+	int flush = 0;
+
+	_vm_unmap_aliases(start, end, flush);
+}
+EXPORT_SYMBOL_GPL(vm_unmap_aliases);
+
+/**
+ * vm_unmap_ram - unmap linear kernel address space set up by vm_map_ram
+ * @mem: the pointer returned by vm_map_ram
+ * @count: the count passed to that vm_map_ram call (cannot unmap partial)
+ */
+void vm_unmap_ram(const void *mem, unsigned int count)
+{
+	unsigned long size = (unsigned long)count << PAGE_SHIFT;
+	unsigned long addr = (unsigned long)kasan_reset_tag(mem);
+	struct vmap_area *va;
+
+	might_sleep();
+	BUG_ON(!addr);
+	BUG_ON(addr < VMALLOC_START);
+	BUG_ON(addr > VMALLOC_END);
+	BUG_ON(!PAGE_ALIGNED(addr));
+
+	kasan_poison_vmalloc(mem, size);
+
+	if (likely(count <= VMAP_MAX_ALLOC)) {
+		debug_check_no_locks_freed(mem, size);
+		vb_free(addr, size);
+		return;
+	}
+
+	va = find_unlink_vmap_area(addr);
+	if (WARN_ON_ONCE(!va))
+		return;
+
+	debug_check_no_locks_freed((void *)va->va_start,
+				    (va->va_end - va->va_start));
+	free_unmap_vmap_area(va);
+}
+EXPORT_SYMBOL(vm_unmap_ram);
+
+/**
+ * vm_map_ram - map pages linearly into kernel virtual address (vmalloc space)
+ * @pages: an array of pointers to the pages to be mapped
+ * @count: number of pages
+ * @node: prefer to allocate data structures on this node
+ *
+ * If you use this function for less than VMAP_MAX_ALLOC pages, it could be
+ * faster than vmap so it's good.  But if you mix long-life and short-life
+ * objects with vm_map_ram(), it could consume lots of address space through
+ * fragmentation (especially on a 32bit machine).  You could see failures in
+ * the end.  Please use this function for short-lived objects.
+ *
+ * Returns: a pointer to the address that has been mapped, or %NULL on failure
+ */
+void *vm_map_ram(struct page **pages, unsigned int count, int node)
+{
+	unsigned long size = (unsigned long)count << PAGE_SHIFT;
+	unsigned long addr;
+	void *mem;
+
+	if (likely(count <= VMAP_MAX_ALLOC)) {
+		mem = vb_alloc(size, GFP_KERNEL);
+		if (IS_ERR(mem))
+			return NULL;
+		addr = (unsigned long)mem;
+	} else {
+		struct vmap_area *va;
+		va = alloc_vmap_area(size, PAGE_SIZE,
+				VMALLOC_START, VMALLOC_END,
+				node, GFP_KERNEL, VMAP_RAM);
+		if (IS_ERR(va))
+			return NULL;
+
+		addr = va->va_start;
+		mem = (void *)addr;
+	}
+
+	if (vmap_pages_range(addr, addr + size, PAGE_KERNEL,
+				pages, PAGE_SHIFT) < 0) {
+		vm_unmap_ram(mem, count);
+		return NULL;
+	}
+
+	/*
+	 * Mark the pages as accessible, now that they are mapped.
+	 * With hardware tag-based KASAN, marking is skipped for
+	 * non-VM_ALLOC mappings, see __kasan_unpoison_vmalloc().
+	 */
+	mem = kasan_unpoison_vmalloc(mem, size, KASAN_VMALLOC_PROT_NORMAL);
+
+	return mem;
+}
+EXPORT_SYMBOL(vm_map_ram);
+
+static struct vm_struct *vmlist __initdata;
+
+static inline unsigned int vm_area_page_order(struct vm_struct *vm)
+{
+#ifdef CONFIG_HAVE_ARCH_HUGE_VMALLOC
+	return vm->page_order;
+#else
+	return 0;
+#endif
+}
+
+static inline void set_vm_area_page_order(struct vm_struct *vm, unsigned int order)
+{
+#ifdef CONFIG_HAVE_ARCH_HUGE_VMALLOC
+	vm->page_order = order;
+#else
+	BUG_ON(order != 0);
+#endif
+}
+
+/**
+ * vm_area_add_early - add vmap area early during boot
+ * @vm: vm_struct to add
+ *
+ * This function is used to add fixed kernel vm area to vmlist before
+ * vmalloc_init() is called.  @vm->addr, @vm->size, and @vm->flags
+ * should contain proper values and the other fields should be zero.
+ *
+ * DO NOT USE THIS FUNCTION UNLESS YOU KNOW WHAT YOU'RE DOING.
+ */
+void __init vm_area_add_early(struct vm_struct *vm)
+{
+	struct vm_struct *tmp, **p;
+
+	BUG_ON(vmap_initialized);
+	for (p = &vmlist; (tmp = *p) != NULL; p = &tmp->next) {
+		if (tmp->addr >= vm->addr) {
+			BUG_ON(tmp->addr < vm->addr + vm->size);
+			break;
+		} else
+			BUG_ON(tmp->addr + tmp->size > vm->addr);
+	}
+	vm->next = *p;
+	*p = vm;
+}
+
+/**
+ * vm_area_register_early - register vmap area early during boot
+ * @vm: vm_struct to register
+ * @align: requested alignment
+ *
+ * This function is used to register kernel vm area before
+ * vmalloc_init() is called.  @vm->size and @vm->flags should contain
+ * proper values on entry and other fields should be zero.  On return,
+ * vm->addr contains the allocated address.
+ *
+ * DO NOT USE THIS FUNCTION UNLESS YOU KNOW WHAT YOU'RE DOING.
+ */
+void __init vm_area_register_early(struct vm_struct *vm, size_t align)
+{
+	unsigned long addr = ALIGN(VMALLOC_START, align);
+	struct vm_struct *cur, **p;
+
+	BUG_ON(vmap_initialized);
+
+	for (p = &vmlist; (cur = *p) != NULL; p = &cur->next) {
+		if ((unsigned long)cur->addr - addr >= vm->size)
+			break;
+		addr = ALIGN((unsigned long)cur->addr + cur->size, align);
+	}
+
+	BUG_ON(addr > VMALLOC_END - vm->size);
+	vm->addr = (void *)addr;
+	vm->next = *p;
+	*p = vm;
+	kasan_populate_early_vm_area_shadow(vm->addr, vm->size);
+}
+
+static void vmap_init_free_space(void)
+{
+	unsigned long vmap_start = 1;
+	const unsigned long vmap_end = ULONG_MAX;
+	struct vmap_area *busy, *free;
+
+	/*
+	 *     B     F     B     B     B     F
+	 * -|-----|.....|-----|-----|-----|.....|-
+	 *  |           The KVA space           |
+	 *  |<--------------------------------->|
+	 */
+	list_for_each_entry(busy, &vmap_area_list, list) {
+		if (busy->va_start - vmap_start > 0) {
+			free = kmem_cache_zalloc(vmap_area_cachep, GFP_NOWAIT);
+			if (!WARN_ON_ONCE(!free)) {
+				free->va_start = vmap_start;
+				free->va_end = busy->va_start;
+
+				insert_vmap_area_augment(free, NULL,
+					&free_vmap_area_root,
+						&free_vmap_area_list);
+			}
+		}
+
+		vmap_start = busy->va_end;
+	}
+
+	if (vmap_end - vmap_start > 0) {
+		free = kmem_cache_zalloc(vmap_area_cachep, GFP_NOWAIT);
+		if (!WARN_ON_ONCE(!free)) {
+			free->va_start = vmap_start;
+			free->va_end = vmap_end;
+
+			insert_vmap_area_augment(free, NULL,
+				&free_vmap_area_root,
+					&free_vmap_area_list);
+		}
+	}
+}
+
+static inline void setup_vmalloc_vm_locked(struct vm_struct *vm,
+	struct vmap_area *va, unsigned long flags, const void *caller)
+{
+	vm->flags = flags;
+	vm->addr = (void *)va->va_start;
+	vm->size = va->va_end - va->va_start;
+	vm->caller = caller;
+	va->vm = vm;
+}
+
+static void setup_vmalloc_vm(struct vm_struct *vm, struct vmap_area *va,
+			      unsigned long flags, const void *caller)
+{
+	spin_lock(&vmap_area_lock);
+	setup_vmalloc_vm_locked(vm, va, flags, caller);
+	spin_unlock(&vmap_area_lock);
+}
+
+static void clear_vm_uninitialized_flag(struct vm_struct *vm)
+{
+	/*
+	 * Before removing VM_UNINITIALIZED,
+	 * we should make sure that vm has proper values.
+	 * Pair with smp_rmb() in show_numa_info().
+	 */
+	smp_wmb();
+	vm->flags &= ~VM_UNINITIALIZED;
+}
+
+static struct vm_struct *__get_vm_area_node(unsigned long size,
+		unsigned long align, unsigned long shift, unsigned long flags,
+		unsigned long start, unsigned long end, int node,
+		gfp_t gfp_mask, const void *caller)
+{
+	struct vmap_area *va;
+	struct vm_struct *area;
+	unsigned long requested_size = size;
+
+	BUG_ON(in_interrupt());
+	size = ALIGN(size, 1ul << shift);
+	if (unlikely(!size))
+		return NULL;
+
+	if (flags & VM_IOREMAP)
+		align = 1ul << clamp_t(int, get_count_order_long(size),
+				       PAGE_SHIFT, IOREMAP_MAX_ORDER);
+
+	area = kzalloc_node(sizeof(*area), gfp_mask & GFP_RECLAIM_MASK, node);
+	if (unlikely(!area))
+		return NULL;
+
+	if (!(flags & VM_NO_GUARD))
+		size += PAGE_SIZE;
+
+	va = alloc_vmap_area(size, align, start, end, node, gfp_mask, 0);
+	if (IS_ERR(va)) {
+		kfree(area);
+		return NULL;
+	}
+
+	setup_vmalloc_vm(area, va, flags, caller);
+
+	/*
+	 * Mark pages for non-VM_ALLOC mappings as accessible. Do it now as a
+	 * best-effort approach, as they can be mapped outside of vmalloc code.
+	 * For VM_ALLOC mappings, the pages are marked as accessible after
+	 * getting mapped in __vmalloc_node_range().
+	 * With hardware tag-based KASAN, marking is skipped for
+	 * non-VM_ALLOC mappings, see __kasan_unpoison_vmalloc().
+	 */
+	if (!(flags & VM_ALLOC))
+		area->addr = kasan_unpoison_vmalloc(area->addr, requested_size,
+						    KASAN_VMALLOC_PROT_NORMAL);
+
+	return area;
+}
+
+struct vm_struct *__get_vm_area_caller(unsigned long size, unsigned long flags,
+				       unsigned long start, unsigned long end,
+				       const void *caller)
+{
+	return __get_vm_area_node(size, 1, PAGE_SHIFT, flags, start, end,
+				  NUMA_NO_NODE, GFP_KERNEL, caller);
+}
+
+/**
+ * get_vm_area - reserve a contiguous kernel virtual area
+ * @size:	 size of the area
+ * @flags:	 %VM_IOREMAP for I/O mappings or VM_ALLOC
+ *
+ * Search an area of @size in the kernel virtual mapping area,
+ * and reserved it for out purposes.  Returns the area descriptor
+ * on success or %NULL on failure.
+ *
+ * Return: the area descriptor on success or %NULL on failure.
+ */
+struct vm_struct *get_vm_area(unsigned long size, unsigned long flags)
+{
+	return __get_vm_area_node(size, 1, PAGE_SHIFT, flags,
+				  VMALLOC_START, VMALLOC_END,
+				  NUMA_NO_NODE, GFP_KERNEL,
+				  __builtin_return_address(0));
+}
+
+struct vm_struct *get_vm_area_caller(unsigned long size, unsigned long flags,
+				const void *caller)
+{
+	return __get_vm_area_node(size, 1, PAGE_SHIFT, flags,
+				  VMALLOC_START, VMALLOC_END,
+				  NUMA_NO_NODE, GFP_KERNEL, caller);
+}
+
+/**
+ * find_vm_area - find a continuous kernel virtual area
+ * @addr:	  base address
+ *
+ * Search for the kernel VM area starting at @addr, and return it.
+ * It is up to the caller to do all required locking to keep the returned
+ * pointer valid.
+ *
+ * Return: the area descriptor on success or %NULL on failure.
+ */
+struct vm_struct *find_vm_area(const void *addr)
+{
+	struct vmap_area *va;
+
+	va = find_vmap_area((unsigned long)addr);
+	if (!va)
+		return NULL;
+
+	return va->vm;
+}
+
+/**
+ * remove_vm_area - find and remove a continuous kernel virtual area
+ * @addr:	    base address
+ *
+ * Search for the kernel VM area starting at @addr, and remove it.
+ * This function returns the found VM area, but using it is NOT safe
+ * on SMP machines, except for its size or flags.
+ *
+ * Return: the area descriptor on success or %NULL on failure.
+ */
+struct vm_struct *remove_vm_area(const void *addr)
+{
+	struct vmap_area *va;
+	struct vm_struct *vm;
+
+	might_sleep();
+
+	if (WARN(!PAGE_ALIGNED(addr), "Trying to vfree() bad address (%p)\n",
+			addr))
+		return NULL;
+
+	va = find_unlink_vmap_area((unsigned long)addr);
+	if (!va || !va->vm)
+		return NULL;
+	vm = va->vm;
+
+	debug_check_no_locks_freed(vm->addr, get_vm_area_size(vm));
+	debug_check_no_obj_freed(vm->addr, get_vm_area_size(vm));
+	kasan_free_module_shadow(vm);
+	kasan_poison_vmalloc(vm->addr, get_vm_area_size(vm));
+
+	free_unmap_vmap_area(va);
+	return vm;
+}
+
+static inline void set_area_direct_map(const struct vm_struct *area,
+				       int (*set_direct_map)(struct page *page))
+{
+	int i;
+
+	/* HUGE_VMALLOC passes small pages to set_direct_map */
+	for (i = 0; i < area->nr_pages; i++)
+		if (page_address(area->pages[i]))
+			set_direct_map(area->pages[i]);
+}
+
+/*
+ * Flush the vm mapping and reset the direct map.
+ */
+static void vm_reset_perms(struct vm_struct *area)
+{
+	unsigned long start = ULONG_MAX, end = 0;
+	unsigned int page_order = vm_area_page_order(area);
+	int flush_dmap = 0;
+	int i;
+
+	/*
+	 * Find the start and end range of the direct mappings to make sure that
+	 * the vm_unmap_aliases() flush includes the direct map.
+	 */
+	for (i = 0; i < area->nr_pages; i += 1U << page_order) {
+		unsigned long addr = (unsigned long)page_address(area->pages[i]);
+
+		if (addr) {
+			unsigned long page_size;
+
+			page_size = PAGE_SIZE << page_order;
+			start = min(addr, start);
+			end = max(addr + page_size, end);
+			flush_dmap = 1;
+		}
+	}
+
+	/*
+	 * Set direct map to something invalid so that it won't be cached if
+	 * there are any accesses after the TLB flush, then flush the TLB and
+	 * reset the direct map permissions to the default.
+	 */
+	set_area_direct_map(area, set_direct_map_invalid_noflush);
+	_vm_unmap_aliases(start, end, flush_dmap);
+	set_area_direct_map(area, set_direct_map_default_noflush);
+}
+
+static void delayed_vfree_work(struct work_struct *w)
+{
+	struct vfree_deferred *p = container_of(w, struct vfree_deferred, wq);
+	struct llist_node *t, *llnode;
+
+	llist_for_each_safe(llnode, t, llist_del_all(&p->list))
+		vfree(llnode);
+}
+
+/**
+ * vfree_atomic - release memory allocated by vmalloc()
+ * @addr:	  memory base address
+ *
+ * This one is just like vfree() but can be called in any atomic context
+ * except NMIs.
+ */
+void vfree_atomic(const void *addr)
+{
+	struct vfree_deferred *p = raw_cpu_ptr(&vfree_deferred);
+
+	BUG_ON(in_nmi());
+	kmemleak_free(addr);
+
+	/*
+	 * Use raw_cpu_ptr() because this can be called from preemptible
+	 * context. Preemption is absolutely fine here, because the llist_add()
+	 * implementation is lockless, so it works even if we are adding to
+	 * another cpu's list. schedule_work() should be fine with this too.
+	 */
+	if (addr && llist_add((struct llist_node *)addr, &p->list))
+		schedule_work(&p->wq);
+}
+
+/**
+ * vfree - Release memory allocated by vmalloc()
+ * @addr:  Memory base address
+ *
+ * Free the virtually continuous memory area starting at @addr, as obtained
+ * from one of the vmalloc() family of APIs.  This will usually also free the
+ * physical memory underlying the virtual allocation, but that memory is
+ * reference counted, so it will not be freed until the last user goes away.
+ *
+ * If @addr is NULL, no operation is performed.
+ *
+ * Context:
+ * May sleep if called *not* from interrupt context.
+ * Must not be called in NMI context (strictly speaking, it could be
+ * if we have CONFIG_ARCH_HAVE_NMI_SAFE_CMPXCHG, but making the calling
+ * conventions for vfree() arch-dependent would be a really bad idea).
+ */
+void vfree(const void *addr)
+{
+	struct vm_struct *vm;
+	int i;
+
+	if (unlikely(in_interrupt())) {
+		vfree_atomic(addr);
+		return;
+	}
+
+	BUG_ON(in_nmi());
+	kmemleak_free(addr);
+	might_sleep();
+
+	if (!addr)
+		return;
+
+	vm = remove_vm_area(addr);
+	if (unlikely(!vm)) {
+		WARN(1, KERN_ERR "Trying to vfree() nonexistent vm area (%p)\n",
+				addr);
+		return;
+	}
+
+	if (unlikely(vm->flags & VM_FLUSH_RESET_PERMS))
+		vm_reset_perms(vm);
+	for (i = 0; i < vm->nr_pages; i++) {
+		struct page *page = vm->pages[i];
+
+		BUG_ON(!page);
+		mod_memcg_page_state(page, MEMCG_VMALLOC, -1);
+		/*
+		 * High-order allocs for huge vmallocs are split, so
+		 * can be freed as an array of order-0 allocations
+		 */
+		__free_page(page);
+		cond_resched();
+	}
+	atomic_long_sub(vm->nr_pages, &nr_vmalloc_pages);
+	kvfree(vm->pages);
+	kfree(vm);
+}
+EXPORT_SYMBOL(vfree);
+
+/**
+ * vunmap - release virtual mapping obtained by vmap()
+ * @addr:   memory base address
+ *
+ * Free the virtually contiguous memory area starting at @addr,
+ * which was created from the page array passed to vmap().
+ *
+ * Must not be called in interrupt context.
+ */
+void vunmap(const void *addr)
+{
+	struct vm_struct *vm;
+
+	BUG_ON(in_interrupt());
+	might_sleep();
+
+	if (!addr)
+		return;
+	vm = remove_vm_area(addr);
+	if (unlikely(!vm)) {
+		WARN(1, KERN_ERR "Trying to vunmap() nonexistent vm area (%p)\n",
+				addr);
+		return;
+	}
+	kfree(vm);
+}
+EXPORT_SYMBOL(vunmap);
+
+/**
+ * vmap - map an array of pages into virtually contiguous space
+ * @pages: array of page pointers
+ * @count: number of pages to map
+ * @flags: vm_area->flags
+ * @prot: page protection for the mapping
+ *
+ * Maps @count pages from @pages into contiguous kernel virtual space.
+ * If @flags contains %VM_MAP_PUT_PAGES the ownership of the pages array itself
+ * (which must be kmalloc or vmalloc memory) and one reference per pages in it
+ * are transferred from the caller to vmap(), and will be freed / dropped when
+ * vfree() is called on the return value.
+ *
+ * Return: the address of the area or %NULL on failure
+ */
+void *vmap(struct page **pages, unsigned int count,
+	   unsigned long flags, pgprot_t prot)
+{
+	struct vm_struct *area;
+	unsigned long addr;
+	unsigned long size;		/* In bytes */
+
+	might_sleep();
+
+	if (WARN_ON_ONCE(flags & VM_FLUSH_RESET_PERMS))
+		return NULL;
+
+	/*
+	 * Your top guard is someone else's bottom guard. Not having a top
+	 * guard compromises someone else's mappings too.
+	 */
+	if (WARN_ON_ONCE(flags & VM_NO_GUARD))
+		flags &= ~VM_NO_GUARD;
+
+	if (count > totalram_pages())
+		return NULL;
+
+	size = (unsigned long)count << PAGE_SHIFT;
+	area = get_vm_area_caller(size, flags, __builtin_return_address(0));
+	if (!area)
+		return NULL;
+
+	addr = (unsigned long)area->addr;
+	if (vmap_pages_range(addr, addr + size, pgprot_nx(prot),
+				pages, PAGE_SHIFT) < 0) {
+		vunmap(area->addr);
+		return NULL;
+	}
+
+	if (flags & VM_MAP_PUT_PAGES) {
+		area->pages = pages;
+		area->nr_pages = count;
+	}
+	return area->addr;
+}
+EXPORT_SYMBOL(vmap);
+
+#ifdef CONFIG_VMAP_PFN
+struct vmap_pfn_data {
+	unsigned long	*pfns;
+	pgprot_t	prot;
+	unsigned int	idx;
+};
+
+static int vmap_pfn_apply(pte_t *pte, unsigned long addr, void *private)
+{
+	struct vmap_pfn_data *data = private;
+	unsigned long pfn = data->pfns[data->idx];
+	pte_t ptent;
+
+	if (WARN_ON_ONCE(pfn_valid(pfn)))
+		return -EINVAL;
+
+	ptent = pte_mkspecial(pfn_pte(pfn, data->prot));
+	set_pte_at(&init_mm, addr, pte, ptent);
+
+	data->idx++;
+	return 0;
+}
+
+/**
+ * vmap_pfn - map an array of PFNs into virtually contiguous space
+ * @pfns: array of PFNs
+ * @count: number of pages to map
+ * @prot: page protection for the mapping
+ *
+ * Maps @count PFNs from @pfns into contiguous kernel virtual space and returns
+ * the start address of the mapping.
+ */
+void *vmap_pfn(unsigned long *pfns, unsigned int count, pgprot_t prot)
+{
+	struct vmap_pfn_data data = { .pfns = pfns, .prot = pgprot_nx(prot) };
+	struct vm_struct *area;
+
+	area = get_vm_area_caller(count * PAGE_SIZE, VM_IOREMAP,
+			__builtin_return_address(0));
+	if (!area)
+		return NULL;
+	if (apply_to_page_range(&init_mm, (unsigned long)area->addr,
+			count * PAGE_SIZE, vmap_pfn_apply, &data)) {
+		free_vm_area(area);
+		return NULL;
+	}
+
+	flush_cache_vmap((unsigned long)area->addr,
+			 (unsigned long)area->addr + count * PAGE_SIZE);
+
+	return area->addr;
+}
+EXPORT_SYMBOL_GPL(vmap_pfn);
+#endif /* CONFIG_VMAP_PFN */
+
+static inline unsigned int
+vm_area_alloc_pages(gfp_t gfp, int nid,
+		unsigned int order, unsigned int nr_pages, struct page **pages)
+{
+	unsigned int nr_allocated = 0;
+	gfp_t alloc_gfp = gfp;
+	bool nofail = false;
+	struct page *page;
+	int i;
+
+	/*
+	 * For order-0 pages we make use of bulk allocator, if
+	 * the page array is partly or not at all populated due
+	 * to fails, fallback to a single page allocator that is
+	 * more permissive.
+	 */
+	if (!order) {
+		/* bulk allocator doesn't support nofail req. officially */
+		gfp_t bulk_gfp = gfp & ~__GFP_NOFAIL;
+
+		while (nr_allocated < nr_pages) {
+			unsigned int nr, nr_pages_request;
+
+			/*
+			 * A maximum allowed request is hard-coded and is 100
+			 * pages per call. That is done in order to prevent a
+			 * long preemption off scenario in the bulk-allocator
+			 * so the range is [1:100].
+			 */
+			nr_pages_request = min(100U, nr_pages - nr_allocated);
+
+			/* memory allocation should consider mempolicy, we can't
+			 * wrongly use nearest node when nid == NUMA_NO_NODE,
+			 * otherwise memory may be allocated in only one node,
+			 * but mempolicy wants to alloc memory by interleaving.
+			 */
+			if (IS_ENABLED(CONFIG_NUMA) && nid == NUMA_NO_NODE)
+				nr = alloc_pages_bulk_array_mempolicy(bulk_gfp,
+							nr_pages_request,
+							pages + nr_allocated);
+
+			else
+				nr = alloc_pages_bulk_array_node(bulk_gfp, nid,
+							nr_pages_request,
+							pages + nr_allocated);
+
+			nr_allocated += nr;
+			cond_resched();
+
+			/*
+			 * If zero or pages were obtained partly,
+			 * fallback to a single page allocator.
+			 */
+			if (nr != nr_pages_request)
+				break;
+		}
+	} else if (gfp & __GFP_NOFAIL) {
+		/*
+		 * Higher order nofail allocations are really expensive and
+		 * potentially dangerous (pre-mature OOM, disruptive reclaim
+		 * and compaction etc.
+		 */
+		alloc_gfp &= ~__GFP_NOFAIL;
+		nofail = true;
+	}
+
+	/* High-order pages or fallback path if "bulk" fails. */
+	while (nr_allocated < nr_pages) {
+		if (fatal_signal_pending(current))
+			break;
+
+		if (nid == NUMA_NO_NODE)
+			page = alloc_pages(alloc_gfp, order);
+		else
+			page = alloc_pages_node(nid, alloc_gfp, order);
+		if (unlikely(!page)) {
+			if (!nofail)
+				break;
+
+			/* fall back to the zero order allocations */
+			alloc_gfp |= __GFP_NOFAIL;
+			order = 0;
+			continue;
+		}
+
+		/*
+		 * Higher order allocations must be able to be treated as
+		 * indepdenent small pages by callers (as they can with
+		 * small-page vmallocs). Some drivers do their own refcounting
+		 * on vmalloc_to_page() pages, some use page->mapping,
+		 * page->lru, etc.
+		 */
+		if (order)
+			split_page(page, order);
+
+		/*
+		 * Careful, we allocate and map page-order pages, but
+		 * tracking is done per PAGE_SIZE page so as to keep the
+		 * vm_struct APIs independent of the physical/mapped size.
+		 */
+		for (i = 0; i < (1U << order); i++)
+			pages[nr_allocated + i] = page + i;
+
+		cond_resched();
+		nr_allocated += 1U << order;
+	}
+
+	return nr_allocated;
+}
+
+static void *__vmalloc_area_node(struct vm_struct *area, gfp_t gfp_mask,
+				 pgprot_t prot, unsigned int page_shift,
+				 int node)
+{
+	const gfp_t nested_gfp = (gfp_mask & GFP_RECLAIM_MASK) | __GFP_ZERO;
+	bool nofail = gfp_mask & __GFP_NOFAIL;
+	unsigned long addr = (unsigned long)area->addr;
+	unsigned long size = get_vm_area_size(area);
+	unsigned long array_size;
+	unsigned int nr_small_pages = size >> PAGE_SHIFT;
+	unsigned int page_order;
+	unsigned int flags;
+	int ret;
+
+	array_size = (unsigned long)nr_small_pages * sizeof(struct page *);
+
+	if (!(gfp_mask & (GFP_DMA | GFP_DMA32)))
+		gfp_mask |= __GFP_HIGHMEM;
+
+	/* Please note that the recursion is strictly bounded. */
+	if (array_size > PAGE_SIZE) {
+		area->pages = __vmalloc_node(array_size, 1, nested_gfp, node,
+					area->caller);
+	} else {
+		area->pages = kmalloc_node(array_size, nested_gfp, node);
+	}
+
+	if (!area->pages) {
+		warn_alloc(gfp_mask, NULL,
+			"vmalloc error: size %lu, failed to allocated page array size %lu",
+			nr_small_pages * PAGE_SIZE, array_size);
+		free_vm_area(area);
+		return NULL;
+	}
+
+	set_vm_area_page_order(area, page_shift - PAGE_SHIFT);
+	page_order = vm_area_page_order(area);
+
+	area->nr_pages = vm_area_alloc_pages(gfp_mask | __GFP_NOWARN,
+		node, page_order, nr_small_pages, area->pages);
+
+	atomic_long_add(area->nr_pages, &nr_vmalloc_pages);
+	if (gfp_mask & __GFP_ACCOUNT) {
+		int i;
+
+		for (i = 0; i < area->nr_pages; i++)
+			mod_memcg_page_state(area->pages[i], MEMCG_VMALLOC, 1);
+	}
+
+	/*
+	 * If not enough pages were obtained to accomplish an
+	 * allocation request, free them via vfree() if any.
+	 */
+	if (area->nr_pages != nr_small_pages) {
+		/*
+		 * vm_area_alloc_pages() can fail due to insufficient memory but
+		 * also:-
+		 *
+		 * - a pending fatal signal
+		 * - insufficient huge page-order pages
+		 *
+		 * Since we always retry allocations at order-0 in the huge page
+		 * case a warning for either is spurious.
+		 */
+		if (!fatal_signal_pending(current) && page_order == 0)
+			warn_alloc(gfp_mask, NULL,
+				"vmalloc error: size %lu, failed to allocate pages",
+				area->nr_pages * PAGE_SIZE);
+		goto fail;
+	}
+
+	/*
+	 * page tables allocations ignore external gfp mask, enforce it
+	 * by the scope API
+	 */
+	if ((gfp_mask & (__GFP_FS | __GFP_IO)) == __GFP_IO)
+		flags = memalloc_nofs_save();
+	else if ((gfp_mask & (__GFP_FS | __GFP_IO)) == 0)
+		flags = memalloc_noio_save();
+
+	do {
+		ret = vmap_pages_range(addr, addr + size, prot, area->pages,
+			page_shift);
+		if (nofail && (ret < 0))
+			schedule_timeout_uninterruptible(1);
+	} while (nofail && (ret < 0));
+
+	if ((gfp_mask & (__GFP_FS | __GFP_IO)) == __GFP_IO)
+		memalloc_nofs_restore(flags);
+	else if ((gfp_mask & (__GFP_FS | __GFP_IO)) == 0)
+		memalloc_noio_restore(flags);
+
+	if (ret < 0) {
+		warn_alloc(gfp_mask, NULL,
+			"vmalloc error: size %lu, failed to map pages",
+			area->nr_pages * PAGE_SIZE);
+		goto fail;
+	}
+
+	return area->addr;
+
+fail:
+	vfree(area->addr);
+	return NULL;
+}
+
+/**
+ * __vmalloc_node_range - allocate virtually contiguous memory
+ * @size:		  allocation size
+ * @align:		  desired alignment
+ * @start:		  vm area range start
+ * @end:		  vm area range end
+ * @gfp_mask:		  flags for the page level allocator
+ * @prot:		  protection mask for the allocated pages
+ * @vm_flags:		  additional vm area flags (e.g. %VM_NO_GUARD)
+ * @node:		  node to use for allocation or NUMA_NO_NODE
+ * @caller:		  caller's return address
+ *
+ * Allocate enough pages to cover @size from the page level
+ * allocator with @gfp_mask flags. Please note that the full set of gfp
+ * flags are not supported. GFP_KERNEL, GFP_NOFS and GFP_NOIO are all
+ * supported.
+ * Zone modifiers are not supported. From the reclaim modifiers
+ * __GFP_DIRECT_RECLAIM is required (aka GFP_NOWAIT is not supported)
+ * and only __GFP_NOFAIL is supported (i.e. __GFP_NORETRY and
+ * __GFP_RETRY_MAYFAIL are not supported).
+ *
+ * __GFP_NOWARN can be used to suppress failures messages.
+ *
+ * Map them into contiguous kernel virtual space, using a pagetable
+ * protection of @prot.
+ *
+ * Return: the address of the area or %NULL on failure
+ */
+void *__vmalloc_node_range(unsigned long size, unsigned long align,
+			unsigned long start, unsigned long end, gfp_t gfp_mask,
+			pgprot_t prot, unsigned long vm_flags, int node,
+			const void *caller)
+{
+	struct vm_struct *area;
+	void *ret;
+	kasan_vmalloc_flags_t kasan_flags = KASAN_VMALLOC_NONE;
+	unsigned long real_size = size;
+	unsigned long real_align = align;
+	unsigned int shift = PAGE_SHIFT;
+
+	if (WARN_ON_ONCE(!size))
+		return NULL;
+
+	if ((size >> PAGE_SHIFT) > totalram_pages()) {
+		warn_alloc(gfp_mask, NULL,
+			"vmalloc error: size %lu, exceeds total pages",
+			real_size);
+		return NULL;
+	}
+
+	if (vmap_allow_huge && (vm_flags & VM_ALLOW_HUGE_VMAP)) {
+		unsigned long size_per_node;
+
+		/*
+		 * Try huge pages. Only try for PAGE_KERNEL allocations,
+		 * others like modules don't yet expect huge pages in
+		 * their allocations due to apply_to_page_range not
+		 * supporting them.
+		 */
+
+		size_per_node = size;
+		if (node == NUMA_NO_NODE)
+			size_per_node /= num_online_nodes();
+		if (arch_vmap_pmd_supported(prot) && size_per_node >= PMD_SIZE)
+			shift = PMD_SHIFT;
+		else
+			shift = arch_vmap_pte_supported_shift(size_per_node);
+
+		align = max(real_align, 1UL << shift);
+		size = ALIGN(real_size, 1UL << shift);
+	}
+
+again:
+	area = __get_vm_area_node(real_size, align, shift, VM_ALLOC |
+				  VM_UNINITIALIZED | vm_flags, start, end, node,
+				  gfp_mask, caller);
+	if (!area) {
+		bool nofail = gfp_mask & __GFP_NOFAIL;
+		warn_alloc(gfp_mask, NULL,
+			"vmalloc error: size %lu, vm_struct allocation failed%s",
+			real_size, (nofail) ? ". Retrying." : "");
+		if (nofail) {
+			schedule_timeout_uninterruptible(1);
+			goto again;
+		}
+		goto fail;
+	}
+
+	/*
+	 * Prepare arguments for __vmalloc_area_node() and
+	 * kasan_unpoison_vmalloc().
+	 */
+	if (pgprot_val(prot) == pgprot_val(PAGE_KERNEL)) {
+		if (kasan_hw_tags_enabled()) {
+			/*
+			 * Modify protection bits to allow tagging.
+			 * This must be done before mapping.
+			 */
+			prot = arch_vmap_pgprot_tagged(prot);
+
+			/*
+			 * Skip page_alloc poisoning and zeroing for physical
+			 * pages backing VM_ALLOC mapping. Memory is instead
+			 * poisoned and zeroed by kasan_unpoison_vmalloc().
+			 */
+			gfp_mask |= __GFP_SKIP_KASAN | __GFP_SKIP_ZERO;
+		}
+
+		/* Take note that the mapping is PAGE_KERNEL. */
+		kasan_flags |= KASAN_VMALLOC_PROT_NORMAL;
+	}
+
+	/* Allocate physical pages and map them into vmalloc space. */
+	ret = __vmalloc_area_node(area, gfp_mask, prot, shift, node);
+	if (!ret)
+		goto fail;
+
+	/*
+	 * Mark the pages as accessible, now that they are mapped.
+	 * The condition for setting KASAN_VMALLOC_INIT should complement the
+	 * one in post_alloc_hook() with regards to the __GFP_SKIP_ZERO check
+	 * to make sure that memory is initialized under the same conditions.
+	 * Tag-based KASAN modes only assign tags to normal non-executable
+	 * allocations, see __kasan_unpoison_vmalloc().
+	 */
+	kasan_flags |= KASAN_VMALLOC_VM_ALLOC;
+	if (!want_init_on_free() && want_init_on_alloc(gfp_mask) &&
+	    (gfp_mask & __GFP_SKIP_ZERO))
+		kasan_flags |= KASAN_VMALLOC_INIT;
+	/* KASAN_VMALLOC_PROT_NORMAL already set if required. */
+	area->addr = kasan_unpoison_vmalloc(area->addr, real_size, kasan_flags);
+
+	/*
+	 * In this function, newly allocated vm_struct has VM_UNINITIALIZED
+	 * flag. It means that vm_struct is not fully initialized.
+	 * Now, it is fully initialized, so remove this flag here.
+	 */
+	clear_vm_uninitialized_flag(area);
+
+	size = PAGE_ALIGN(size);
+	if (!(vm_flags & VM_DEFER_KMEMLEAK))
+		kmemleak_vmalloc(area, size, gfp_mask);
+
+	return area->addr;
+
+fail:
+	if (shift > PAGE_SHIFT) {
+		shift = PAGE_SHIFT;
+		align = real_align;
+		size = real_size;
+		goto again;
+	}
+
+	return NULL;
+}
+
+/**
+ * __vmalloc_node - allocate virtually contiguous memory
+ * @size:	    allocation size
+ * @align:	    desired alignment
+ * @gfp_mask:	    flags for the page level allocator
+ * @node:	    node to use for allocation or NUMA_NO_NODE
+ * @caller:	    caller's return address
+ *
+ * Allocate enough pages to cover @size from the page level allocator with
+ * @gfp_mask flags.  Map them into contiguous kernel virtual space.
+ *
+ * Reclaim modifiers in @gfp_mask - __GFP_NORETRY, __GFP_RETRY_MAYFAIL
+ * and __GFP_NOFAIL are not supported
+ *
+ * Any use of gfp flags outside of GFP_KERNEL should be consulted
+ * with mm people.
+ *
+ * Return: pointer to the allocated memory or %NULL on error
+ */
+void *__vmalloc_node(unsigned long size, unsigned long align,
+			    gfp_t gfp_mask, int node, const void *caller)
+{
+	return __vmalloc_node_range(size, align, VMALLOC_START, VMALLOC_END,
+				gfp_mask, PAGE_KERNEL, 0, node, caller);
+}
+/*
+ * This is only for performance analysis of vmalloc and stress purpose.
+ * It is required by vmalloc test module, therefore do not use it other
+ * than that.
+ */
+#ifdef CONFIG_TEST_VMALLOC_MODULE
+EXPORT_SYMBOL_GPL(__vmalloc_node);
+#endif
+
+void *__vmalloc(unsigned long size, gfp_t gfp_mask)
+{
+	return __vmalloc_node(size, 1, gfp_mask, NUMA_NO_NODE,
+				__builtin_return_address(0));
+}
+EXPORT_SYMBOL(__vmalloc);
+
+/**
+ * vmalloc - allocate virtually contiguous memory
+ * @size:    allocation size
+ *
+ * Allocate enough pages to cover @size from the page level
+ * allocator and map them into contiguous kernel virtual space.
+ *
+ * For tight control over page level allocator and protection flags
+ * use __vmalloc() instead.
+ *
+ * Return: pointer to the allocated memory or %NULL on error
+ */
+void *vmalloc(unsigned long size)
+{
+	return __vmalloc_node(size, 1, GFP_KERNEL, NUMA_NO_NODE,
+				__builtin_return_address(0));
+}
+EXPORT_SYMBOL(vmalloc);
+
+/**
+ * vmalloc_huge - allocate virtually contiguous memory, allow huge pages
+ * @size:      allocation size
+ * @gfp_mask:  flags for the page level allocator
+ *
+ * Allocate enough pages to cover @size from the page level
+ * allocator and map them into contiguous kernel virtual space.
+ * If @size is greater than or equal to PMD_SIZE, allow using
+ * huge pages for the memory
+ *
+ * Return: pointer to the allocated memory or %NULL on error
+ */
+void *vmalloc_huge(unsigned long size, gfp_t gfp_mask)
+{
+	return __vmalloc_node_range(size, 1, VMALLOC_START, VMALLOC_END,
+				    gfp_mask, PAGE_KERNEL, VM_ALLOW_HUGE_VMAP,
+				    NUMA_NO_NODE, __builtin_return_address(0));
+}
+EXPORT_SYMBOL_GPL(vmalloc_huge);
+
+/**
+ * vzalloc - allocate virtually contiguous memory with zero fill
+ * @size:    allocation size
+ *
+ * Allocate enough pages to cover @size from the page level
+ * allocator and map them into contiguous kernel virtual space.
+ * The memory allocated is set to zero.
+ *
+ * For tight control over page level allocator and protection flags
+ * use __vmalloc() instead.
+ *
+ * Return: pointer to the allocated memory or %NULL on error
+ */
+void *vzalloc(unsigned long size)
+{
+	return __vmalloc_node(size, 1, GFP_KERNEL | __GFP_ZERO, NUMA_NO_NODE,
+				__builtin_return_address(0));
+}
+EXPORT_SYMBOL(vzalloc);
+
+/**
+ * vmalloc_user - allocate zeroed virtually contiguous memory for userspace
+ * @size: allocation size
+ *
+ * The resulting memory area is zeroed so it can be mapped to userspace
+ * without leaking data.
+ *
+ * Return: pointer to the allocated memory or %NULL on error
+ */
+void *vmalloc_user(unsigned long size)
+{
+	return __vmalloc_node_range(size, SHMLBA,  VMALLOC_START, VMALLOC_END,
+				    GFP_KERNEL | __GFP_ZERO, PAGE_KERNEL,
+				    VM_USERMAP, NUMA_NO_NODE,
+				    __builtin_return_address(0));
+}
+EXPORT_SYMBOL(vmalloc_user);
+
+/**
+ * vmalloc_node - allocate memory on a specific node
+ * @size:	  allocation size
+ * @node:	  numa node
+ *
+ * Allocate enough pages to cover @size from the page level
+ * allocator and map them into contiguous kernel virtual space.
+ *
+ * For tight control over page level allocator and protection flags
+ * use __vmalloc() instead.
+ *
+ * Return: pointer to the allocated memory or %NULL on error
+ */
+void *vmalloc_node(unsigned long size, int node)
+{
+	return __vmalloc_node(size, 1, GFP_KERNEL, node,
+			__builtin_return_address(0));
+}
+EXPORT_SYMBOL(vmalloc_node);
+
+/**
+ * vzalloc_node - allocate memory on a specific node with zero fill
+ * @size:	allocation size
+ * @node:	numa node
+ *
+ * Allocate enough pages to cover @size from the page level
+ * allocator and map them into contiguous kernel virtual space.
+ * The memory allocated is set to zero.
+ *
+ * Return: pointer to the allocated memory or %NULL on error
+ */
+void *vzalloc_node(unsigned long size, int node)
+{
+	return __vmalloc_node(size, 1, GFP_KERNEL | __GFP_ZERO, node,
+				__builtin_return_address(0));
+}
+EXPORT_SYMBOL(vzalloc_node);
+
+#if defined(CONFIG_64BIT) && defined(CONFIG_ZONE_DMA32)
+#define GFP_VMALLOC32 (GFP_DMA32 | GFP_KERNEL)
+#elif defined(CONFIG_64BIT) && defined(CONFIG_ZONE_DMA)
+#define GFP_VMALLOC32 (GFP_DMA | GFP_KERNEL)
+#else
+/*
+ * 64b systems should always have either DMA or DMA32 zones. For others
+ * GFP_DMA32 should do the right thing and use the normal zone.
+ */
+#define GFP_VMALLOC32 (GFP_DMA32 | GFP_KERNEL)
+#endif
+
+/**
+ * vmalloc_32 - allocate virtually contiguous memory (32bit addressable)
+ * @size:	allocation size
+ *
+ * Allocate enough 32bit PA addressable pages to cover @size from the
+ * page level allocator and map them into contiguous kernel virtual space.
+ *
+ * Return: pointer to the allocated memory or %NULL on error
+ */
+void *vmalloc_32(unsigned long size)
+{
+	return __vmalloc_node(size, 1, GFP_VMALLOC32, NUMA_NO_NODE,
+			__builtin_return_address(0));
+}
+EXPORT_SYMBOL(vmalloc_32);
+
+/**
+ * vmalloc_32_user - allocate zeroed virtually contiguous 32bit memory
+ * @size:	     allocation size
+ *
+ * The resulting memory area is 32bit addressable and zeroed so it can be
+ * mapped to userspace without leaking data.
+ *
+ * Return: pointer to the allocated memory or %NULL on error
+ */
+void *vmalloc_32_user(unsigned long size)
+{
+	return __vmalloc_node_range(size, SHMLBA,  VMALLOC_START, VMALLOC_END,
+				    GFP_VMALLOC32 | __GFP_ZERO, PAGE_KERNEL,
+				    VM_USERMAP, NUMA_NO_NODE,
+				    __builtin_return_address(0));
+}
+EXPORT_SYMBOL(vmalloc_32_user);
+
+/*
+ * Atomically zero bytes in the iterator.
+ *
+ * Returns the number of zeroed bytes.
+ */
+static size_t zero_iter(struct iov_iter *iter, size_t count)
+{
+	size_t remains = count;
+
+	while (remains > 0) {
+		size_t num, copied;
+
+		num = min_t(size_t, remains, PAGE_SIZE);
+		copied = copy_page_to_iter_nofault(ZERO_PAGE(0), 0, num, iter);
+		remains -= copied;
+
+		if (copied < num)
+			break;
+	}
+
+	return count - remains;
+}
+
+/*
+ * small helper routine, copy contents to iter from addr.
+ * If the page is not present, fill zero.
+ *
+ * Returns the number of copied bytes.
+ */
+static size_t aligned_vread_iter(struct iov_iter *iter,
+				 const char *addr, size_t count)
+{
+	size_t remains = count;
+	struct page *page;
+
+	while (remains > 0) {
+		unsigned long offset, length;
+		size_t copied = 0;
+
+		offset = offset_in_page(addr);
+		length = PAGE_SIZE - offset;
+		if (length > remains)
+			length = remains;
+		page = vmalloc_to_page(addr);
+		/*
+		 * To do safe access to this _mapped_ area, we need lock. But
+		 * adding lock here means that we need to add overhead of
+		 * vmalloc()/vfree() calls for this _debug_ interface, rarely
+		 * used. Instead of that, we'll use an local mapping via
+		 * copy_page_to_iter_nofault() and accept a small overhead in
+		 * this access function.
+		 */
+		if (page)
+			copied = copy_page_to_iter_nofault(page, offset,
+							   length, iter);
+		else
+			copied = zero_iter(iter, length);
+
+		addr += copied;
+		remains -= copied;
+
+		if (copied != length)
+			break;
+	}
+
+	return count - remains;
+}
+
+/*
+ * Read from a vm_map_ram region of memory.
+ *
+ * Returns the number of copied bytes.
+ */
+static size_t vmap_ram_vread_iter(struct iov_iter *iter, const char *addr,
+				  size_t count, unsigned long flags)
+{
+	char *start;
+	struct vmap_block *vb;
+	struct xarray *xa;
+	unsigned long offset;
+	unsigned int rs, re;
+	size_t remains, n;
+
+	/*
+	 * If it's area created by vm_map_ram() interface directly, but
+	 * not further subdividing and delegating management to vmap_block,
+	 * handle it here.
+	 */
+	if (!(flags & VMAP_BLOCK))
+		return aligned_vread_iter(iter, addr, count);
+
+	remains = count;
+
+	/*
+	 * Area is split into regions and tracked with vmap_block, read out
+	 * each region and zero fill the hole between regions.
+	 */
+	xa = addr_to_vb_xa((unsigned long) addr);
+	vb = xa_load(xa, addr_to_vb_idx((unsigned long)addr));
+	if (!vb)
+		goto finished_zero;
+
+	spin_lock(&vb->lock);
+	if (bitmap_empty(vb->used_map, VMAP_BBMAP_BITS)) {
+		spin_unlock(&vb->lock);
+		goto finished_zero;
+	}
+
+	for_each_set_bitrange(rs, re, vb->used_map, VMAP_BBMAP_BITS) {
+		size_t copied;
+
+		if (remains == 0)
+			goto finished;
+
+		start = vmap_block_vaddr(vb->va->va_start, rs);
+
+		if (addr < start) {
+			size_t to_zero = min_t(size_t, start - addr, remains);
+			size_t zeroed = zero_iter(iter, to_zero);
+
+			addr += zeroed;
+			remains -= zeroed;
+
+			if (remains == 0 || zeroed != to_zero)
+				goto finished;
+		}
+
+		/*it could start reading from the middle of used region*/
+		offset = offset_in_page(addr);
+		n = ((re - rs + 1) << PAGE_SHIFT) - offset;
+		if (n > remains)
+			n = remains;
+
+		copied = aligned_vread_iter(iter, start + offset, n);
+
+		addr += copied;
+		remains -= copied;
+
+		if (copied != n)
+			goto finished;
+	}
+
+	spin_unlock(&vb->lock);
+
+finished_zero:
+	/* zero-fill the left dirty or free regions */
+	return count - remains + zero_iter(iter, remains);
+finished:
+	/* We couldn't copy/zero everything */
+	spin_unlock(&vb->lock);
+	return count - remains;
+}
+
+/**
+ * vread_iter() - read vmalloc area in a safe way to an iterator.
+ * @iter:         the iterator to which data should be written.
+ * @addr:         vm address.
+ * @count:        number of bytes to be read.
+ *
+ * This function checks that addr is a valid vmalloc'ed area, and
+ * copy data from that area to a given buffer. If the given memory range
+ * of [addr...addr+count) includes some valid address, data is copied to
+ * proper area of @buf. If there are memory holes, they'll be zero-filled.
+ * IOREMAP area is treated as memory hole and no copy is done.
+ *
+ * If [addr...addr+count) doesn't includes any intersects with alive
+ * vm_struct area, returns 0. @buf should be kernel's buffer.
+ *
+ * Note: In usual ops, vread() is never necessary because the caller
+ * should know vmalloc() area is valid and can use memcpy().
+ * This is for routines which have to access vmalloc area without
+ * any information, as /proc/kcore.
+ *
+ * Return: number of bytes for which addr and buf should be increased
+ * (same number as @count) or %0 if [addr...addr+count) doesn't
+ * include any intersection with valid vmalloc area
+ */
+long vread_iter(struct iov_iter *iter, const char *addr, size_t count)
+{
+	struct vmap_area *va;
+	struct vm_struct *vm;
+	char *vaddr;
+	size_t n, size, flags, remains;
+
+	addr = kasan_reset_tag(addr);
+
+	/* Don't allow overflow */
+	if ((unsigned long) addr + count < count)
+		count = -(unsigned long) addr;
+
+	remains = count;
+
+	spin_lock(&vmap_area_lock);
+	va = find_vmap_area_exceed_addr((unsigned long)addr);
+	if (!va)
+		goto finished_zero;
+
+	/* no intersects with alive vmap_area */
+	if ((unsigned long)addr + remains <= va->va_start)
+		goto finished_zero;
+
+	list_for_each_entry_from(va, &vmap_area_list, list) {
+		size_t copied;
+
+		if (remains == 0)
+			goto finished;
+
+		vm = va->vm;
+		flags = va->flags & VMAP_FLAGS_MASK;
+		/*
+		 * VMAP_BLOCK indicates a sub-type of vm_map_ram area, need
+		 * be set together with VMAP_RAM.
+		 */
+		WARN_ON(flags == VMAP_BLOCK);
+
+		if (!vm && !flags)
+			continue;
+
+		if (vm && (vm->flags & VM_UNINITIALIZED))
+			continue;
+
+		/* Pair with smp_wmb() in clear_vm_uninitialized_flag() */
+		smp_rmb();
+
+		vaddr = (char *) va->va_start;
+		size = vm ? get_vm_area_size(vm) : va_size(va);
+
+		if (addr >= vaddr + size)
+			continue;
+
+		if (addr < vaddr) {
+			size_t to_zero = min_t(size_t, vaddr - addr, remains);
+			size_t zeroed = zero_iter(iter, to_zero);
+
+			addr += zeroed;
+			remains -= zeroed;
+
+			if (remains == 0 || zeroed != to_zero)
+				goto finished;
+		}
+
+		n = vaddr + size - addr;
+		if (n > remains)
+			n = remains;
+
+		if (flags & VMAP_RAM)
+			copied = vmap_ram_vread_iter(iter, addr, n, flags);
+		else if (!(vm->flags & VM_IOREMAP))
+			copied = aligned_vread_iter(iter, addr, n);
+		else /* IOREMAP area is treated as memory hole */
+			copied = zero_iter(iter, n);
+
+		addr += copied;
+		remains -= copied;
+
+		if (copied != n)
+			goto finished;
+	}
+
+finished_zero:
+	spin_unlock(&vmap_area_lock);
+	/* zero-fill memory holes */
+	return count - remains + zero_iter(iter, remains);
+finished:
+	/* Nothing remains, or We couldn't copy/zero everything. */
+	spin_unlock(&vmap_area_lock);
+
+	return count - remains;
+}
+
+/**
+ * remap_vmalloc_range_partial - map vmalloc pages to userspace
+ * @vma:		vma to cover
+ * @uaddr:		target user address to start at
+ * @kaddr:		virtual address of vmalloc kernel memory
+ * @pgoff:		offset from @kaddr to start at
+ * @size:		size of map area
+ *
+ * Returns:	0 for success, -Exxx on failure
+ *
+ * This function checks that @kaddr is a valid vmalloc'ed area,
+ * and that it is big enough to cover the range starting at
+ * @uaddr in @vma. Will return failure if that criteria isn't
+ * met.
+ *
+ * Similar to remap_pfn_range() (see mm/memory.c)
+ */
+int remap_vmalloc_range_partial(struct vm_area_struct *vma, unsigned long uaddr,
+				void *kaddr, unsigned long pgoff,
+				unsigned long size)
+{
+	struct vm_struct *area;
+	unsigned long off;
+	unsigned long end_index;
+
+	if (check_shl_overflow(pgoff, PAGE_SHIFT, &off))
+		return -EINVAL;
+
+	size = PAGE_ALIGN(size);
+
+	if (!PAGE_ALIGNED(uaddr) || !PAGE_ALIGNED(kaddr))
+		return -EINVAL;
+
+	area = find_vm_area(kaddr);
+	if (!area)
+		return -EINVAL;
+
+	if (!(area->flags & (VM_USERMAP | VM_DMA_COHERENT)))
+		return -EINVAL;
+
+	if (check_add_overflow(size, off, &end_index) ||
+	    end_index > get_vm_area_size(area))
+		return -EINVAL;
+	kaddr += off;
+
+	do {
+		struct page *page = vmalloc_to_page(kaddr);
+		int ret;
+
+		ret = vm_insert_page(vma, uaddr, page);
+		if (ret)
+			return ret;
+
+		uaddr += PAGE_SIZE;
+		kaddr += PAGE_SIZE;
+		size -= PAGE_SIZE;
+	} while (size > 0);
+
+	vm_flags_set(vma, VM_DONTEXPAND | VM_DONTDUMP);
+
+	return 0;
+}
+
+/**
+ * remap_vmalloc_range - map vmalloc pages to userspace
+ * @vma:		vma to cover (map full range of vma)
+ * @addr:		vmalloc memory
+ * @pgoff:		number of pages into addr before first page to map
+ *
+ * Returns:	0 for success, -Exxx on failure
+ *
+ * This function checks that addr is a valid vmalloc'ed area, and
+ * that it is big enough to cover the vma. Will return failure if
+ * that criteria isn't met.
+ *
+ * Similar to remap_pfn_range() (see mm/memory.c)
+ */
+int remap_vmalloc_range(struct vm_area_struct *vma, void *addr,
+						unsigned long pgoff)
+{
+	return remap_vmalloc_range_partial(vma, vma->vm_start,
+					   addr, pgoff,
+					   vma->vm_end - vma->vm_start);
+}
+EXPORT_SYMBOL(remap_vmalloc_range);
+
+void free_vm_area(struct vm_struct *area)
+{
+	struct vm_struct *ret;
+	ret = remove_vm_area(area->addr);
+	BUG_ON(ret != area);
+	kfree(area);
+}
+EXPORT_SYMBOL_GPL(free_vm_area);
+
+#ifdef CONFIG_SMP
+static struct vmap_area *node_to_va(struct rb_node *n)
+{
+	return rb_entry_safe(n, struct vmap_area, rb_node);
+}
+
+/**
+ * pvm_find_va_enclose_addr - find the vmap_area @addr belongs to
+ * @addr: target address
+ *
+ * Returns: vmap_area if it is found. If there is no such area
+ *   the first highest(reverse order) vmap_area is returned
+ *   i.e. va->va_start < addr && va->va_end < addr or NULL
+ *   if there are no any areas before @addr.
+ */
+static struct vmap_area *
+pvm_find_va_enclose_addr(unsigned long addr)
+{
+	struct vmap_area *va, *tmp;
+	struct rb_node *n;
+
+	n = free_vmap_area_root.rb_node;
+	va = NULL;
+
+	while (n) {
+		tmp = rb_entry(n, struct vmap_area, rb_node);
+		if (tmp->va_start <= addr) {
+			va = tmp;
+			if (tmp->va_end >= addr)
+				break;
+
+			n = n->rb_right;
+		} else {
+			n = n->rb_left;
+		}
+	}
+
+	return va;
+}
+
+/**
+ * pvm_determine_end_from_reverse - find the highest aligned address
+ * of free block below VMALLOC_END
+ * @va:
+ *   in - the VA we start the search(reverse order);
+ *   out - the VA with the highest aligned end address.
+ * @align: alignment for required highest address
+ *
+ * Returns: determined end address within vmap_area
+ */
+static unsigned long
+pvm_determine_end_from_reverse(struct vmap_area **va, unsigned long align)
+{
+	unsigned long vmalloc_end = VMALLOC_END & ~(align - 1);
+	unsigned long addr;
+
+	if (likely(*va)) {
+		list_for_each_entry_from_reverse((*va),
+				&free_vmap_area_list, list) {
+			addr = min((*va)->va_end & ~(align - 1), vmalloc_end);
+			if ((*va)->va_start < addr)
+				return addr;
+		}
+	}
+
+	return 0;
+}
+
+/**
+ * pcpu_get_vm_areas - allocate vmalloc areas for percpu allocator
+ * @offsets: array containing offset of each area
+ * @sizes: array containing size of each area
+ * @nr_vms: the number of areas to allocate
+ * @align: alignment, all entries in @offsets and @sizes must be aligned to this
+ *
+ * Returns: kmalloc'd vm_struct pointer array pointing to allocated
+ *	    vm_structs on success, %NULL on failure
+ *
+ * Percpu allocator wants to use congruent vm areas so that it can
+ * maintain the offsets among percpu areas.  This function allocates
+ * congruent vmalloc areas for it with GFP_KERNEL.  These areas tend to
+ * be scattered pretty far, distance between two areas easily going up
+ * to gigabytes.  To avoid interacting with regular vmallocs, these
+ * areas are allocated from top.
+ *
+ * Despite its complicated look, this allocator is rather simple. It
+ * does everything top-down and scans free blocks from the end looking
+ * for matching base. While scanning, if any of the areas do not fit the
+ * base address is pulled down to fit the area. Scanning is repeated till
+ * all the areas fit and then all necessary data structures are inserted
+ * and the result is returned.
+ */
+struct vm_struct **pcpu_get_vm_areas(const unsigned long *offsets,
+				     const size_t *sizes, int nr_vms,
+				     size_t align)
+{
+	const unsigned long vmalloc_start = ALIGN(VMALLOC_START, align);
+	const unsigned long vmalloc_end = VMALLOC_END & ~(align - 1);
+	struct vmap_area **vas, *va;
+	struct vm_struct **vms;
+	int area, area2, last_area, term_area;
+	unsigned long base, start, size, end, last_end, orig_start, orig_end;
+	bool purged = false;
+
+	/* verify parameters and allocate data structures */
+	BUG_ON(offset_in_page(align) || !is_power_of_2(align));
+	for (last_area = 0, area = 0; area < nr_vms; area++) {
+		start = offsets[area];
+		end = start + sizes[area];
+
+		/* is everything aligned properly? */
+		BUG_ON(!IS_ALIGNED(offsets[area], align));
+		BUG_ON(!IS_ALIGNED(sizes[area], align));
+
+		/* detect the area with the highest address */
+		if (start > offsets[last_area])
+			last_area = area;
+
+		for (area2 = area + 1; area2 < nr_vms; area2++) {
+			unsigned long start2 = offsets[area2];
+			unsigned long end2 = start2 + sizes[area2];
+
+			BUG_ON(start2 < end && start < end2);
+		}
+	}
+	last_end = offsets[last_area] + sizes[last_area];
+
+	if (vmalloc_end - vmalloc_start < last_end) {
+		WARN_ON(true);
+		return NULL;
+	}
+
+	vms = kcalloc(nr_vms, sizeof(vms[0]), GFP_KERNEL);
+	vas = kcalloc(nr_vms, sizeof(vas[0]), GFP_KERNEL);
+	if (!vas || !vms)
+		goto err_free2;
+
+	for (area = 0; area < nr_vms; area++) {
+		vas[area] = kmem_cache_zalloc(vmap_area_cachep, GFP_KERNEL);
+		vms[area] = kzalloc(sizeof(struct vm_struct), GFP_KERNEL);
+		if (!vas[area] || !vms[area])
+			goto err_free;
+	}
+retry:
+	spin_lock(&free_vmap_area_lock);
+
+	/* start scanning - we scan from the top, begin with the last area */
+	area = term_area = last_area;
+	start = offsets[area];
+	end = start + sizes[area];
+
+	va = pvm_find_va_enclose_addr(vmalloc_end);
+	base = pvm_determine_end_from_reverse(&va, align) - end;
+
+	while (true) {
+		/*
+		 * base might have underflowed, add last_end before
+		 * comparing.
+		 */
+		if (base + last_end < vmalloc_start + last_end)
+			goto overflow;
+
+		/*
+		 * Fitting base has not been found.
+		 */
+		if (va == NULL)
+			goto overflow;
+
+		/*
+		 * If required width exceeds current VA block, move
+		 * base downwards and then recheck.
+		 */
+		if (base + end > va->va_end) {
+			base = pvm_determine_end_from_reverse(&va, align) - end;
+			term_area = area;
+			continue;
+		}
+
+		/*
+		 * If this VA does not fit, move base downwards and recheck.
+		 */
+		if (base + start < va->va_start) {
+			va = node_to_va(rb_prev(&va->rb_node));
+			base = pvm_determine_end_from_reverse(&va, align) - end;
+			term_area = area;
+			continue;
+		}
+
+		/*
+		 * This area fits, move on to the previous one.  If
+		 * the previous one is the terminal one, we're done.
+		 */
+		area = (area + nr_vms - 1) % nr_vms;
+		if (area == term_area)
+			break;
+
+		start = offsets[area];
+		end = start + sizes[area];
+		va = pvm_find_va_enclose_addr(base + end);
+	}
+
+	/* we've found a fitting base, insert all va's */
+	for (area = 0; area < nr_vms; area++) {
+		int ret;
+
+		start = base + offsets[area];
+		size = sizes[area];
+
+		va = pvm_find_va_enclose_addr(start);
+		if (WARN_ON_ONCE(va == NULL))
+			/* It is a BUG(), but trigger recovery instead. */
+			goto recovery;
+
+		ret = adjust_va_to_fit_type(&free_vmap_area_root,
+					    &free_vmap_area_list,
+					    va, start, size);
+		if (WARN_ON_ONCE(unlikely(ret)))
+			/* It is a BUG(), but trigger recovery instead. */
+			goto recovery;
+
+		/* Allocated area. */
+		va = vas[area];
+		va->va_start = start;
+		va->va_end = start + size;
+	}
+
+	spin_unlock(&free_vmap_area_lock);
+
+	/* populate the kasan shadow space */
+	for (area = 0; area < nr_vms; area++) {
+		if (kasan_populate_vmalloc(vas[area]->va_start, sizes[area]))
+			goto err_free_shadow;
+	}
+
+	/* insert all vm's */
+	spin_lock(&vmap_area_lock);
+	for (area = 0; area < nr_vms; area++) {
+		insert_vmap_area(vas[area], &vmap_area_root, &vmap_area_list);
+
+		setup_vmalloc_vm_locked(vms[area], vas[area], VM_ALLOC,
+				 pcpu_get_vm_areas);
+	}
+	spin_unlock(&vmap_area_lock);
+
+	/*
+	 * Mark allocated areas as accessible. Do it now as a best-effort
+	 * approach, as they can be mapped outside of vmalloc code.
+	 * With hardware tag-based KASAN, marking is skipped for
+	 * non-VM_ALLOC mappings, see __kasan_unpoison_vmalloc().
+	 */
+	for (area = 0; area < nr_vms; area++)
+		vms[area]->addr = kasan_unpoison_vmalloc(vms[area]->addr,
+				vms[area]->size, KASAN_VMALLOC_PROT_NORMAL);
+
+	kfree(vas);
+	return vms;
+
+recovery:
+	/*
+	 * Remove previously allocated areas. There is no
+	 * need in removing these areas from the busy tree,
+	 * because they are inserted only on the final step
+	 * and when pcpu_get_vm_areas() is success.
+	 */
+	while (area--) {
+		orig_start = vas[area]->va_start;
+		orig_end = vas[area]->va_end;
+		va = merge_or_add_vmap_area_augment(vas[area], &free_vmap_area_root,
+				&free_vmap_area_list);
+		if (va)
+			kasan_release_vmalloc(orig_start, orig_end,
+				va->va_start, va->va_end);
+		vas[area] = NULL;
+	}
+
+overflow:
+	spin_unlock(&free_vmap_area_lock);
+	if (!purged) {
+		reclaim_and_purge_vmap_areas();
+		purged = true;
+
+		/* Before "retry", check if we recover. */
+		for (area = 0; area < nr_vms; area++) {
+			if (vas[area])
+				continue;
+
+			vas[area] = kmem_cache_zalloc(
+				vmap_area_cachep, GFP_KERNEL);
+			if (!vas[area])
+				goto err_free;
+		}
+
+		goto retry;
+	}
+
+err_free:
+	for (area = 0; area < nr_vms; area++) {
+		if (vas[area])
+			kmem_cache_free(vmap_area_cachep, vas[area]);
+
+		kfree(vms[area]);
+	}
+err_free2:
+	kfree(vas);
+	kfree(vms);
+	return NULL;
+
+err_free_shadow:
+	spin_lock(&free_vmap_area_lock);
+	/*
+	 * We release all the vmalloc shadows, even the ones for regions that
+	 * hadn't been successfully added. This relies on kasan_release_vmalloc
+	 * being able to tolerate this case.
+	 */
+	for (area = 0; area < nr_vms; area++) {
+		orig_start = vas[area]->va_start;
+		orig_end = vas[area]->va_end;
+		va = merge_or_add_vmap_area_augment(vas[area], &free_vmap_area_root,
+				&free_vmap_area_list);
+		if (va)
+			kasan_release_vmalloc(orig_start, orig_end,
+				va->va_start, va->va_end);
+		vas[area] = NULL;
+		kfree(vms[area]);
+	}
+	spin_unlock(&free_vmap_area_lock);
+	kfree(vas);
+	kfree(vms);
+	return NULL;
+}
+
+/**
+ * pcpu_free_vm_areas - free vmalloc areas for percpu allocator
+ * @vms: vm_struct pointer array returned by pcpu_get_vm_areas()
+ * @nr_vms: the number of allocated areas
+ *
+ * Free vm_structs and the array allocated by pcpu_get_vm_areas().
+ */
+void pcpu_free_vm_areas(struct vm_struct **vms, int nr_vms)
+{
+	int i;
+
+	for (i = 0; i < nr_vms; i++)
+		free_vm_area(vms[i]);
+	kfree(vms);
+}
+#endif	/* CONFIG_SMP */
+
+#ifdef CONFIG_PRINTK
+bool vmalloc_dump_obj(void *object)
+{
+	void *objp = (void *)PAGE_ALIGN((unsigned long)object);
+	const void *caller;
+	struct vm_struct *vm;
+	struct vmap_area *va;
+	unsigned long addr;
+	unsigned int nr_pages;
+
+	if (!spin_trylock(&vmap_area_lock))
+		return false;
+	va = __find_vmap_area((unsigned long)objp, &vmap_area_root);
+	if (!va) {
+		spin_unlock(&vmap_area_lock);
+		return false;
+	}
+
+	vm = va->vm;
+	if (!vm) {
+		spin_unlock(&vmap_area_lock);
+		return false;
+	}
+	addr = (unsigned long)vm->addr;
+	caller = vm->caller;
+	nr_pages = vm->nr_pages;
+	spin_unlock(&vmap_area_lock);
+	pr_cont(" %u-page vmalloc region starting at %#lx allocated at %pS\n",
+		nr_pages, addr, caller);
+	return true;
+}
+#endif
+
+#ifdef CONFIG_PROC_FS
+static void *s_start(struct seq_file *m, loff_t *pos)
+	__acquires(&vmap_purge_lock)
+	__acquires(&vmap_area_lock)
+{
+	mutex_lock(&vmap_purge_lock);
+	spin_lock(&vmap_area_lock);
+
+	return seq_list_start(&vmap_area_list, *pos);
+}
+
+static void *s_next(struct seq_file *m, void *p, loff_t *pos)
+{
+	return seq_list_next(p, &vmap_area_list, pos);
+}
+
+static void s_stop(struct seq_file *m, void *p)
+	__releases(&vmap_area_lock)
+	__releases(&vmap_purge_lock)
+{
+	spin_unlock(&vmap_area_lock);
+	mutex_unlock(&vmap_purge_lock);
+}
+
+static void show_numa_info(struct seq_file *m, struct vm_struct *v)
+{
+	if (IS_ENABLED(CONFIG_NUMA)) {
+		unsigned int nr, *counters = m->private;
+		unsigned int step = 1U << vm_area_page_order(v);
+
+		if (!counters)
+			return;
+
+		if (v->flags & VM_UNINITIALIZED)
+			return;
+		/* Pair with smp_wmb() in clear_vm_uninitialized_flag() */
+		smp_rmb();
+
+		memset(counters, 0, nr_node_ids * sizeof(unsigned int));
+
+		for (nr = 0; nr < v->nr_pages; nr += step)
+			counters[page_to_nid(v->pages[nr])] += step;
+		for_each_node_state(nr, N_HIGH_MEMORY)
+			if (counters[nr])
+				seq_printf(m, " N%u=%u", nr, counters[nr]);
+	}
+}
+
+static void show_purge_info(struct seq_file *m)
+{
+	struct vmap_area *va;
+
+	spin_lock(&purge_vmap_area_lock);
+	list_for_each_entry(va, &purge_vmap_area_list, list) {
+		seq_printf(m, "0x%pK-0x%pK %7ld unpurged vm_area\n",
+			(void *)va->va_start, (void *)va->va_end,
+			va->va_end - va->va_start);
+	}
+	spin_unlock(&purge_vmap_area_lock);
+}
+
+static int s_show(struct seq_file *m, void *p)
+{
+	struct vmap_area *va;
+	struct vm_struct *v;
+
+	va = list_entry(p, struct vmap_area, list);
+
+	if (!va->vm) {
+		if (va->flags & VMAP_RAM)
+			seq_printf(m, "0x%pK-0x%pK %7ld vm_map_ram\n",
+				(void *)va->va_start, (void *)va->va_end,
+				va->va_end - va->va_start);
+
+		goto final;
+	}
+
+	v = va->vm;
+
+	seq_printf(m, "0x%pK-0x%pK %7ld",
+		v->addr, v->addr + v->size, v->size);
+
+	if (v->caller)
+		seq_printf(m, " %pS", v->caller);
+
+	if (v->nr_pages)
+		seq_printf(m, " pages=%d", v->nr_pages);
+
+	if (v->phys_addr)
+		seq_printf(m, " phys=%pa", &v->phys_addr);
+
+	if (v->flags & VM_IOREMAP)
+		seq_puts(m, " ioremap");
+
+	if (v->flags & VM_ALLOC)
+		seq_puts(m, " vmalloc");
+
+	if (v->flags & VM_MAP)
+		seq_puts(m, " vmap");
+
+	if (v->flags & VM_USERMAP)
+		seq_puts(m, " user");
+
+	if (v->flags & VM_DMA_COHERENT)
+		seq_puts(m, " dma-coherent");
+
+	if (is_vmalloc_addr(v->pages))
+		seq_puts(m, " vpages");
+
+	show_numa_info(m, v);
+	seq_putc(m, '\n');
+
+	/*
+	 * As a final step, dump "unpurged" areas.
+	 */
+final:
+	if (list_is_last(&va->list, &vmap_area_list))
+		show_purge_info(m);
+
+	return 0;
+}
+
+static const struct seq_operations vmalloc_op = {
+	.start = s_start,
+	.next = s_next,
+	.stop = s_stop,
+	.show = s_show,
+};
+
+static int __init proc_vmalloc_init(void)
+{
+	if (IS_ENABLED(CONFIG_NUMA))
+		proc_create_seq_private("vmallocinfo", 0400, NULL,
+				&vmalloc_op,
+				nr_node_ids * sizeof(unsigned int), NULL);
+	else
+		proc_create_seq("vmallocinfo", 0400, NULL, &vmalloc_op);
+	return 0;
+}
+module_init(proc_vmalloc_init);
+
+#endif
+
+void __init vmalloc_init(void)
+{
+	struct vmap_area *va;
+	struct vm_struct *tmp;
+	int i;
+
+	/*
+	 * Create the cache for vmap_area objects.
+	 */
+	vmap_area_cachep = KMEM_CACHE(vmap_area, SLAB_PANIC);
+
+	for_each_possible_cpu(i) {
+		struct vmap_block_queue *vbq;
+		struct vfree_deferred *p;
+
+		vbq = &per_cpu(vmap_block_queue, i);
+		spin_lock_init(&vbq->lock);
+		INIT_LIST_HEAD(&vbq->free);
+		p = &per_cpu(vfree_deferred, i);
+		init_llist_head(&p->list);
+		INIT_WORK(&p->wq, delayed_vfree_work);
+		xa_init(&vbq->vmap_blocks);
+	}
+
+	/* Import existing vmlist entries. */
+	for (tmp = vmlist; tmp; tmp = tmp->next) {
+		va = kmem_cache_zalloc(vmap_area_cachep, GFP_NOWAIT);
+		if (WARN_ON_ONCE(!va))
+			continue;
+
+		va->va_start = (unsigned long)tmp->addr;
+		va->va_end = va->va_start + tmp->size;
+		va->vm = tmp;
+		insert_vmap_area(va, &vmap_area_root, &vmap_area_list);
+	}
+
+	/*
+	 * Now we can initialize a free vmap space.
+	 */
+	vmap_init_free_space();
+	vmap_initialized = true;
+}