Revision e700898fa075c69b3ae02b702ab57fb75e1a82ec authored by Mike Kravetz on 12 December 2022, 23:50:41 UTC, committed by Andrew Morton on 21 December 2022, 22:31:52 UTC
Commit bbff39cc6cbc ("hugetlb: allocate vma lock for all sharable vmas") removed the pmd sharable checks in the vma lock helper routines. However, it left the functional version of helper routines behind #ifdef CONFIG_ARCH_WANT_HUGE_PMD_SHARE. Therefore, the vma lock is not being used for sharable vmas on architectures that do not support pmd sharing. On these architectures, a potential fault/truncation race is exposed that could leave pages in a hugetlb file past i_size until the file is removed. Move the functional vma lock helpers outside the ifdef, and remove the non-functional stubs. Since the vma lock is not just for pmd sharing, rename the routine __vma_shareable_flags_pmd. Link: https://lkml.kernel.org/r/20221212235042.178355-1-mike.kravetz@oracle.com Fixes: bbff39cc6cbc ("hugetlb: allocate vma lock for all sharable vmas") Signed-off-by: Mike Kravetz <mike.kravetz@oracle.com> Reviewed-by: Miaohe Lin <linmiaohe@huawei.com> Cc: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com> Cc: David Hildenbrand <david@redhat.com> Cc: James Houghton <jthoughton@google.com> Cc: Mina Almasry <almasrymina@google.com> Cc: Muchun Song <songmuchun@bytedance.com> Cc: Naoya Horiguchi <naoya.horiguchi@linux.dev> Cc: Peter Xu <peterx@redhat.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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pgalloc-track.h
/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _LINUX_PGALLOC_TRACK_H
#define _LINUX_PGALLOC_TRACK_H
#if defined(CONFIG_MMU)
static inline p4d_t *p4d_alloc_track(struct mm_struct *mm, pgd_t *pgd,
unsigned long address,
pgtbl_mod_mask *mod_mask)
{
if (unlikely(pgd_none(*pgd))) {
if (__p4d_alloc(mm, pgd, address))
return NULL;
*mod_mask |= PGTBL_PGD_MODIFIED;
}
return p4d_offset(pgd, address);
}
static inline pud_t *pud_alloc_track(struct mm_struct *mm, p4d_t *p4d,
unsigned long address,
pgtbl_mod_mask *mod_mask)
{
if (unlikely(p4d_none(*p4d))) {
if (__pud_alloc(mm, p4d, address))
return NULL;
*mod_mask |= PGTBL_P4D_MODIFIED;
}
return pud_offset(p4d, address);
}
static inline pmd_t *pmd_alloc_track(struct mm_struct *mm, pud_t *pud,
unsigned long address,
pgtbl_mod_mask *mod_mask)
{
if (unlikely(pud_none(*pud))) {
if (__pmd_alloc(mm, pud, address))
return NULL;
*mod_mask |= PGTBL_PUD_MODIFIED;
}
return pmd_offset(pud, address);
}
#endif /* CONFIG_MMU */
#define pte_alloc_kernel_track(pmd, address, mask) \
((unlikely(pmd_none(*(pmd))) && \
(__pte_alloc_kernel(pmd) || ({*(mask)|=PGTBL_PMD_MODIFIED;0;})))?\
NULL: pte_offset_kernel(pmd, address))
#endif /* _LINUX_PGALLOC_TRACK_H */
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