linux/arch/sparc/mm/hugetlbpage.c

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License cleanup: add SPDX GPL-2.0 license identifier to files with no license Many source files in the tree are missing licensing information, which makes it harder for compliance tools to determine the correct license. By default all files without license information are under the default license of the kernel, which is GPL version 2. Update the files which contain no license information with the 'GPL-2.0' SPDX license identifier. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This patch is based on work done by Thomas Gleixner and Kate Stewart and Philippe Ombredanne. How this work was done: Patches were generated and checked against linux-4.14-rc6 for a subset of the use cases: - file had no licensing information it it. - file was a */uapi/* one with no licensing information in it, - file was a */uapi/* one with existing licensing information, Further patches will be generated in subsequent months to fix up cases where non-standard license headers were used, and references to license had to be inferred by heuristics based on keywords. The analysis to determine which SPDX License Identifier to be applied to a file was done in a spreadsheet of side by side results from of the output of two independent scanners (ScanCode & Windriver) producing SPDX tag:value files created by Philippe Ombredanne. Philippe prepared the base worksheet, and did an initial spot review of a few 1000 files. The 4.13 kernel was the starting point of the analysis with 60,537 files assessed. Kate Stewart did a file by file comparison of the scanner results in the spreadsheet to determine which SPDX license identifier(s) to be applied to the file. She confirmed any determination that was not immediately clear with lawyers working with the Linux Foundation. Criteria used to select files for SPDX license identifier tagging was: - Files considered eligible had to be source code files. - Make and config files were included as candidates if they contained >5 lines of source - File already had some variant of a license header in it (even if <5 lines). All documentation files were explicitly excluded. The following heuristics were used to determine which SPDX license identifiers to apply. - when both scanners couldn't find any license traces, file was considered to have no license information in it, and the top level COPYING file license applied. For non */uapi/* files that summary was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 11139 and resulted in the first patch in this series. If that file was a */uapi/* path one, it was "GPL-2.0 WITH Linux-syscall-note" otherwise it was "GPL-2.0". Results of that was: SPDX license identifier # files ---------------------------------------------------|------- GPL-2.0 WITH Linux-syscall-note 930 and resulted in the second patch in this series. - if a file had some form of licensing information in it, and was one of the */uapi/* ones, it was denoted with the Linux-syscall-note if any GPL family license was found in the file or had no licensing in it (per prior point). Results summary: SPDX license identifier # files ---------------------------------------------------|------ GPL-2.0 WITH Linux-syscall-note 270 GPL-2.0+ WITH Linux-syscall-note 169 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause) 21 ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause) 17 LGPL-2.1+ WITH Linux-syscall-note 15 GPL-1.0+ WITH Linux-syscall-note 14 ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause) 5 LGPL-2.0+ WITH Linux-syscall-note 4 LGPL-2.1 WITH Linux-syscall-note 3 ((GPL-2.0 WITH Linux-syscall-note) OR MIT) 3 ((GPL-2.0 WITH Linux-syscall-note) AND MIT) 1 and that resulted in the third patch in this series. - when the two scanners agreed on the detected license(s), that became the concluded license(s). - when there was disagreement between the two scanners (one detected a license but the other didn't, or they both detected different licenses) a manual inspection of the file occurred. - In most cases a manual inspection of the information in the file resulted in a clear resolution of the license that should apply (and which scanner probably needed to revisit its heuristics). - When it was not immediately clear, the license identifier was confirmed with lawyers working with the Linux Foundation. - If there was any question as to the appropriate license identifier, the file was flagged for further research and to be revisited later in time. In total, over 70 hours of logged manual review was done on the spreadsheet to determine the SPDX license identifiers to apply to the source files by Kate, Philippe, Thomas and, in some cases, confirmation by lawyers working with the Linux Foundation. Kate also obtained a third independent scan of the 4.13 code base from FOSSology, and compared selected files where the other two scanners disagreed against that SPDX file, to see if there was new insights. The Windriver scanner is based on an older version of FOSSology in part, so they are related. Thomas did random spot checks in about 500 files from the spreadsheets for the uapi headers and agreed with SPDX license identifier in the files he inspected. For the non-uapi files Thomas did random spot checks in about 15000 files. In initial set of patches against 4.14-rc6, 3 files were found to have copy/paste license identifier errors, and have been fixed to reflect the correct identifier. Additionally Philippe spent 10 hours this week doing a detailed manual inspection and review of the 12,461 patched files from the initial patch version early this week with: - a full scancode scan run, collecting the matched texts, detected license ids and scores - reviewing anything where there was a license detected (about 500+ files) to ensure that the applied SPDX license was correct - reviewing anything where there was no detection but the patch license was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied SPDX license was correct This produced a worksheet with 20 files needing minor correction. This worksheet was then exported into 3 different .csv files for the different types of files to be modified. These .csv files were then reviewed by Greg. Thomas wrote a script to parse the csv files and add the proper SPDX tag to the file, in the format that the file expected. This script was further refined by Greg based on the output to detect more types of files automatically and to distinguish between header and source .c files (which need different comment types.) Finally Greg ran the script using the .csv files to generate the patches. Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Reviewed-by: Philippe Ombredanne <pombredanne@nexb.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-11-01 22:07:57 +08:00
// SPDX-License-Identifier: GPL-2.0
/*
* SPARC64 Huge TLB page support.
*
* Copyright (C) 2002, 2003, 2006 David S. Miller (davem@davemloft.net)
*/
#include <linux/fs.h>
#include <linux/mm.h>
#include <linux/sched/mm.h>
#include <linux/hugetlb.h>
#include <linux/pagemap.h>
#include <linux/sysctl.h>
#include <asm/mman.h>
#include <asm/pgalloc.h>
#include <asm/pgtable.h>
#include <asm/tlb.h>
#include <asm/tlbflush.h>
#include <asm/cacheflush.h>
#include <asm/mmu_context.h>
/* Slightly simplified from the non-hugepage variant because by
* definition we don't have to worry about any page coloring stuff
*/
static unsigned long hugetlb_get_unmapped_area_bottomup(struct file *filp,
unsigned long addr,
unsigned long len,
unsigned long pgoff,
unsigned long flags)
{
struct hstate *h = hstate_file(filp);
unsigned long task_size = TASK_SIZE;
struct vm_unmapped_area_info info;
if (test_thread_flag(TIF_32BIT))
task_size = STACK_TOP32;
info.flags = 0;
info.length = len;
info.low_limit = TASK_UNMAPPED_BASE;
info.high_limit = min(task_size, VA_EXCLUDE_START);
info.align_mask = PAGE_MASK & ~huge_page_mask(h);
info.align_offset = 0;
addr = vm_unmapped_area(&info);
if ((addr & ~PAGE_MASK) && task_size > VA_EXCLUDE_END) {
VM_BUG_ON(addr != -ENOMEM);
info.low_limit = VA_EXCLUDE_END;
info.high_limit = task_size;
addr = vm_unmapped_area(&info);
}
return addr;
}
static unsigned long
hugetlb_get_unmapped_area_topdown(struct file *filp, const unsigned long addr0,
const unsigned long len,
const unsigned long pgoff,
const unsigned long flags)
{
struct hstate *h = hstate_file(filp);
struct mm_struct *mm = current->mm;
unsigned long addr = addr0;
struct vm_unmapped_area_info info;
/* This should only ever run for 32-bit processes. */
BUG_ON(!test_thread_flag(TIF_32BIT));
info.flags = VM_UNMAPPED_AREA_TOPDOWN;
info.length = len;
info.low_limit = PAGE_SIZE;
info.high_limit = mm->mmap_base;
info.align_mask = PAGE_MASK & ~huge_page_mask(h);
info.align_offset = 0;
addr = vm_unmapped_area(&info);
/*
* A failed mmap() very likely causes application failure,
* so fall back to the bottom-up function here. This scenario
* can happen with large stack limits and large mmap()
* allocations.
*/
if (addr & ~PAGE_MASK) {
VM_BUG_ON(addr != -ENOMEM);
info.flags = 0;
info.low_limit = TASK_UNMAPPED_BASE;
info.high_limit = STACK_TOP32;
addr = vm_unmapped_area(&info);
}
return addr;
}
unsigned long
hugetlb_get_unmapped_area(struct file *file, unsigned long addr,
unsigned long len, unsigned long pgoff, unsigned long flags)
{
struct hstate *h = hstate_file(file);
struct mm_struct *mm = current->mm;
struct vm_area_struct *vma;
unsigned long task_size = TASK_SIZE;
if (test_thread_flag(TIF_32BIT))
task_size = STACK_TOP32;
if (len & ~huge_page_mask(h))
return -EINVAL;
if (len > task_size)
return -ENOMEM;
if (flags & MAP_FIXED) {
if (prepare_hugepage_range(file, addr, len))
return -EINVAL;
return addr;
}
if (addr) {
addr = ALIGN(addr, huge_page_size(h));
vma = find_vma(mm, addr);
if (task_size - len >= addr &&
mm: larger stack guard gap, between vmas Stack guard page is a useful feature to reduce a risk of stack smashing into a different mapping. We have been using a single page gap which is sufficient to prevent having stack adjacent to a different mapping. But this seems to be insufficient in the light of the stack usage in userspace. E.g. glibc uses as large as 64kB alloca() in many commonly used functions. Others use constructs liks gid_t buffer[NGROUPS_MAX] which is 256kB or stack strings with MAX_ARG_STRLEN. This will become especially dangerous for suid binaries and the default no limit for the stack size limit because those applications can be tricked to consume a large portion of the stack and a single glibc call could jump over the guard page. These attacks are not theoretical, unfortunatelly. Make those attacks less probable by increasing the stack guard gap to 1MB (on systems with 4k pages; but make it depend on the page size because systems with larger base pages might cap stack allocations in the PAGE_SIZE units) which should cover larger alloca() and VLA stack allocations. It is obviously not a full fix because the problem is somehow inherent, but it should reduce attack space a lot. One could argue that the gap size should be configurable from userspace, but that can be done later when somebody finds that the new 1MB is wrong for some special case applications. For now, add a kernel command line option (stack_guard_gap) to specify the stack gap size (in page units). Implementation wise, first delete all the old code for stack guard page: because although we could get away with accounting one extra page in a stack vma, accounting a larger gap can break userspace - case in point, a program run with "ulimit -S -v 20000" failed when the 1MB gap was counted for RLIMIT_AS; similar problems could come with RLIMIT_MLOCK and strict non-overcommit mode. Instead of keeping gap inside the stack vma, maintain the stack guard gap as a gap between vmas: using vm_start_gap() in place of vm_start (or vm_end_gap() in place of vm_end if VM_GROWSUP) in just those few places which need to respect the gap - mainly arch_get_unmapped_area(), and and the vma tree's subtree_gap support for that. Original-patch-by: Oleg Nesterov <oleg@redhat.com> Original-patch-by: Michal Hocko <mhocko@suse.com> Signed-off-by: Hugh Dickins <hughd@google.com> Acked-by: Michal Hocko <mhocko@suse.com> Tested-by: Helge Deller <deller@gmx.de> # parisc Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-06-19 19:03:24 +08:00
(!vma || addr + len <= vm_start_gap(vma)))
return addr;
}
if (mm->get_unmapped_area == arch_get_unmapped_area)
return hugetlb_get_unmapped_area_bottomup(file, addr, len,
pgoff, flags);
else
return hugetlb_get_unmapped_area_topdown(file, addr, len,
pgoff, flags);
}
static pte_t sun4u_hugepage_shift_to_tte(pte_t entry, unsigned int shift)
{
return entry;
}
static pte_t sun4v_hugepage_shift_to_tte(pte_t entry, unsigned int shift)
{
unsigned long hugepage_size = _PAGE_SZ4MB_4V;
pte_val(entry) = pte_val(entry) & ~_PAGE_SZALL_4V;
switch (shift) {
case HPAGE_16GB_SHIFT:
hugepage_size = _PAGE_SZ16GB_4V;
pte_val(entry) |= _PAGE_PUD_HUGE;
break;
case HPAGE_2GB_SHIFT:
hugepage_size = _PAGE_SZ2GB_4V;
pte_val(entry) |= _PAGE_PMD_HUGE;
break;
case HPAGE_256MB_SHIFT:
hugepage_size = _PAGE_SZ256MB_4V;
pte_val(entry) |= _PAGE_PMD_HUGE;
break;
case HPAGE_SHIFT:
pte_val(entry) |= _PAGE_PMD_HUGE;
break;
case HPAGE_64K_SHIFT:
hugepage_size = _PAGE_SZ64K_4V;
break;
default:
WARN_ONCE(1, "unsupported hugepage shift=%u\n", shift);
}
pte_val(entry) = pte_val(entry) | hugepage_size;
return entry;
}
static pte_t hugepage_shift_to_tte(pte_t entry, unsigned int shift)
{
if (tlb_type == hypervisor)
return sun4v_hugepage_shift_to_tte(entry, shift);
else
return sun4u_hugepage_shift_to_tte(entry, shift);
}
pte_t arch_make_huge_pte(pte_t entry, struct vm_area_struct *vma,
struct page *page, int writeable)
{
unsigned int shift = huge_page_shift(hstate_vma(vma));
return hugepage_shift_to_tte(entry, shift);
}
static unsigned int sun4v_huge_tte_to_shift(pte_t entry)
{
unsigned long tte_szbits = pte_val(entry) & _PAGE_SZALL_4V;
unsigned int shift;
switch (tte_szbits) {
case _PAGE_SZ16GB_4V:
shift = HPAGE_16GB_SHIFT;
break;
case _PAGE_SZ2GB_4V:
shift = HPAGE_2GB_SHIFT;
break;
case _PAGE_SZ256MB_4V:
shift = HPAGE_256MB_SHIFT;
break;
case _PAGE_SZ4MB_4V:
shift = REAL_HPAGE_SHIFT;
break;
case _PAGE_SZ64K_4V:
shift = HPAGE_64K_SHIFT;
break;
default:
shift = PAGE_SHIFT;
break;
}
return shift;
}
static unsigned int sun4u_huge_tte_to_shift(pte_t entry)
{
unsigned long tte_szbits = pte_val(entry) & _PAGE_SZALL_4U;
unsigned int shift;
switch (tte_szbits) {
case _PAGE_SZ256MB_4U:
shift = HPAGE_256MB_SHIFT;
break;
case _PAGE_SZ4MB_4U:
shift = REAL_HPAGE_SHIFT;
break;
case _PAGE_SZ64K_4U:
shift = HPAGE_64K_SHIFT;
break;
default:
shift = PAGE_SHIFT;
break;
}
return shift;
}
static unsigned int huge_tte_to_shift(pte_t entry)
{
unsigned long shift;
if (tlb_type == hypervisor)
shift = sun4v_huge_tte_to_shift(entry);
else
shift = sun4u_huge_tte_to_shift(entry);
if (shift == PAGE_SHIFT)
WARN_ONCE(1, "tto_to_shift: invalid hugepage tte=0x%lx\n",
pte_val(entry));
return shift;
}
static unsigned long huge_tte_to_size(pte_t pte)
{
unsigned long size = 1UL << huge_tte_to_shift(pte);
if (size == REAL_HPAGE_SIZE)
size = HPAGE_SIZE;
return size;
}
pte_t *huge_pte_alloc(struct mm_struct *mm,
unsigned long addr, unsigned long sz)
{
pgd_t *pgd;
pud_t *pud;
pmd_t *pmd;
pgd = pgd_offset(mm, addr);
pud = pud_alloc(mm, pgd, addr);
if (!pud)
return NULL;
if (sz >= PUD_SIZE)
return (pte_t *)pud;
pmd = pmd_alloc(mm, pud, addr);
if (!pmd)
return NULL;
if (sz >= PMD_SIZE)
return (pte_t *)pmd;
return pte_alloc_map(mm, pmd, addr);
}
mm/hugetlb: add size parameter to huge_pte_offset() A poisoned or migrated hugepage is stored as a swap entry in the page tables. On architectures that support hugepages consisting of contiguous page table entries (such as on arm64) this leads to ambiguity in determining the page table entry to return in huge_pte_offset() when a poisoned entry is encountered. Let's remove the ambiguity by adding a size parameter to convey additional information about the requested address. Also fixup the definition/usage of huge_pte_offset() throughout the tree. Link: http://lkml.kernel.org/r/20170522133604.11392-4-punit.agrawal@arm.com Signed-off-by: Punit Agrawal <punit.agrawal@arm.com> Acked-by: Steve Capper <steve.capper@arm.com> Cc: Catalin Marinas <catalin.marinas@arm.com> Cc: Will Deacon <will.deacon@arm.com> Cc: Tony Luck <tony.luck@intel.com> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: James Hogan <james.hogan@imgtec.com> (odd fixer:METAG ARCHITECTURE) Cc: Ralf Baechle <ralf@linux-mips.org> (supporter:MIPS) Cc: "James E.J. Bottomley" <jejb@parisc-linux.org> Cc: Helge Deller <deller@gmx.de> Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Paul Mackerras <paulus@samba.org> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Martin Schwidefsky <schwidefsky@de.ibm.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Yoshinori Sato <ysato@users.sourceforge.jp> Cc: Rich Felker <dalias@libc.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: Chris Metcalf <cmetcalf@mellanox.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Michal Hocko <mhocko@suse.com> Cc: Mike Kravetz <mike.kravetz@oracle.com> Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com> Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com> Cc: Hillf Danton <hillf.zj@alibaba-inc.com> Cc: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-07-07 06:39:42 +08:00
pte_t *huge_pte_offset(struct mm_struct *mm,
unsigned long addr, unsigned long sz)
{
pgd_t *pgd;
pud_t *pud;
pmd_t *pmd;
pgd = pgd_offset(mm, addr);
if (pgd_none(*pgd))
return NULL;
pud = pud_offset(pgd, addr);
if (pud_none(*pud))
return NULL;
if (is_hugetlb_pud(*pud))
return (pte_t *)pud;
pmd = pmd_offset(pud, addr);
if (pmd_none(*pmd))
return NULL;
if (is_hugetlb_pmd(*pmd))
return (pte_t *)pmd;
return pte_offset_map(pmd, addr);
}
void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
pte_t *ptep, pte_t entry)
{
unsigned int nptes, orig_shift, shift;
unsigned long i, size;
pte_t orig;
size = huge_tte_to_size(entry);
shift = PAGE_SHIFT;
if (size >= PUD_SIZE)
shift = PUD_SHIFT;
else if (size >= PMD_SIZE)
shift = PMD_SHIFT;
else
shift = PAGE_SHIFT;
nptes = size >> shift;
if (!pte_present(*ptep) && pte_present(entry))
mm->context.hugetlb_pte_count += nptes;
addr &= ~(size - 1);
orig = *ptep;
orig_shift = pte_none(orig) ? PAGE_SHIFT : huge_tte_to_shift(orig);
for (i = 0; i < nptes; i++)
ptep[i] = __pte(pte_val(entry) + (i << shift));
maybe_tlb_batch_add(mm, addr, ptep, orig, 0, orig_shift);
/* An HPAGE_SIZE'ed page is composed of two REAL_HPAGE_SIZE'ed pages */
if (size == HPAGE_SIZE)
maybe_tlb_batch_add(mm, addr + REAL_HPAGE_SIZE, ptep, orig, 0,
orig_shift);
}
pte_t huge_ptep_get_and_clear(struct mm_struct *mm, unsigned long addr,
pte_t *ptep)
{
unsigned int i, nptes, orig_shift, shift;
unsigned long size;
pte_t entry;
entry = *ptep;
size = huge_tte_to_size(entry);
shift = PAGE_SHIFT;
if (size >= PUD_SIZE)
shift = PUD_SHIFT;
else if (size >= PMD_SIZE)
shift = PMD_SHIFT;
else
shift = PAGE_SHIFT;
nptes = size >> shift;
orig_shift = pte_none(entry) ? PAGE_SHIFT : huge_tte_to_shift(entry);
if (pte_present(entry))
mm->context.hugetlb_pte_count -= nptes;
addr &= ~(size - 1);
for (i = 0; i < nptes; i++)
ptep[i] = __pte(0UL);
maybe_tlb_batch_add(mm, addr, ptep, entry, 0, orig_shift);
/* An HPAGE_SIZE'ed page is composed of two REAL_HPAGE_SIZE'ed pages */
if (size == HPAGE_SIZE)
maybe_tlb_batch_add(mm, addr + REAL_HPAGE_SIZE, ptep, entry, 0,
orig_shift);
return entry;
}
int pmd_huge(pmd_t pmd)
{
return !pmd_none(pmd) &&
(pmd_val(pmd) & (_PAGE_VALID|_PAGE_PMD_HUGE)) != _PAGE_VALID;
}
int pud_huge(pud_t pud)
{
return !pud_none(pud) &&
(pud_val(pud) & (_PAGE_VALID|_PAGE_PUD_HUGE)) != _PAGE_VALID;
}
static void hugetlb_free_pte_range(struct mmu_gather *tlb, pmd_t *pmd,
unsigned long addr)
{
pgtable_t token = pmd_pgtable(*pmd);
pmd_clear(pmd);
pte_free_tlb(tlb, token, addr);
atomic_long_dec(&tlb->mm->nr_ptes);
}
static void hugetlb_free_pmd_range(struct mmu_gather *tlb, pud_t *pud,
unsigned long addr, unsigned long end,
unsigned long floor, unsigned long ceiling)
{
pmd_t *pmd;
unsigned long next;
unsigned long start;
start = addr;
pmd = pmd_offset(pud, addr);
do {
next = pmd_addr_end(addr, end);
if (pmd_none(*pmd))
continue;
if (is_hugetlb_pmd(*pmd))
pmd_clear(pmd);
else
hugetlb_free_pte_range(tlb, pmd, addr);
} while (pmd++, addr = next, addr != end);
start &= PUD_MASK;
if (start < floor)
return;
if (ceiling) {
ceiling &= PUD_MASK;
if (!ceiling)
return;
}
if (end - 1 > ceiling - 1)
return;
pmd = pmd_offset(pud, start);
pud_clear(pud);
pmd_free_tlb(tlb, pmd, start);
mm_dec_nr_pmds(tlb->mm);
}
static void hugetlb_free_pud_range(struct mmu_gather *tlb, pgd_t *pgd,
unsigned long addr, unsigned long end,
unsigned long floor, unsigned long ceiling)
{
pud_t *pud;
unsigned long next;
unsigned long start;
start = addr;
pud = pud_offset(pgd, addr);
do {
next = pud_addr_end(addr, end);
if (pud_none_or_clear_bad(pud))
continue;
if (is_hugetlb_pud(*pud))
pud_clear(pud);
else
hugetlb_free_pmd_range(tlb, pud, addr, next, floor,
ceiling);
} while (pud++, addr = next, addr != end);
start &= PGDIR_MASK;
if (start < floor)
return;
if (ceiling) {
ceiling &= PGDIR_MASK;
if (!ceiling)
return;
}
if (end - 1 > ceiling - 1)
return;
pud = pud_offset(pgd, start);
pgd_clear(pgd);
pud_free_tlb(tlb, pud, start);
mm_dec_nr_puds(tlb->mm);
}
void hugetlb_free_pgd_range(struct mmu_gather *tlb,
unsigned long addr, unsigned long end,
unsigned long floor, unsigned long ceiling)
{
pgd_t *pgd;
unsigned long next;
addr &= PMD_MASK;
if (addr < floor) {
addr += PMD_SIZE;
if (!addr)
return;
}
if (ceiling) {
ceiling &= PMD_MASK;
if (!ceiling)
return;
}
if (end - 1 > ceiling - 1)
end -= PMD_SIZE;
if (addr > end - 1)
return;
pgd = pgd_offset(tlb->mm, addr);
do {
next = pgd_addr_end(addr, end);
if (pgd_none_or_clear_bad(pgd))
continue;
hugetlb_free_pud_range(tlb, pgd, addr, next, floor, ceiling);
} while (pgd++, addr = next, addr != end);
}