diff options
author | Peter Xu <peterx@redhat.com> | 2024-03-27 18:23:27 +0300 |
---|---|---|
committer | Andrew Morton <akpm@linux-foundation.org> | 2024-04-26 06:56:22 +0300 |
commit | 878b0c4516210b613468fea827f4cc0f71b87970 (patch) | |
tree | 901d6a03b9e317ab732a22c28f7844ff0b4fb3cc | |
parent | f3c94c625fe38823cc8010e60b9cc23fbf058ee3 (diff) | |
download | linux-878b0c4516210b613468fea827f4cc0f71b87970.tar.xz |
mm/gup: handle hugetlb for no_page_table()
no_page_table() is not yet used for hugetlb code paths. Make it prepared.
The major difference here is hugetlb will return -EFAULT as long as page
cache does not exist, even if VM_SHARED. See hugetlb_follow_page_mask().
Pass "address" into no_page_table() too, as hugetlb will need it.
Link: https://lkml.kernel.org/r/20240327152332.950956-9-peterx@redhat.com
Signed-off-by: Peter Xu <peterx@redhat.com>
Reviewed-by: Christoph Hellwig <hch@infradead.org>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Tested-by: Ryan Roberts <ryan.roberts@arm.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Andrew Jones <andrew.jones@linux.dev>
Cc: Aneesh Kumar K.V (IBM) <aneesh.kumar@kernel.org>
Cc: Axel Rasmussen <axelrasmussen@google.com>
Cc: Christophe Leroy <christophe.leroy@csgroup.eu>
Cc: David Hildenbrand <david@redhat.com>
Cc: James Houghton <jthoughton@google.com>
Cc: John Hubbard <jhubbard@nvidia.com>
Cc: Kirill A. Shutemov <kirill@shutemov.name>
Cc: Lorenzo Stoakes <lstoakes@gmail.com>
Cc: Matthew Wilcox (Oracle) <willy@infradead.org>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: "Mike Rapoport (IBM)" <rppt@kernel.org>
Cc: Muchun Song <muchun.song@linux.dev>
Cc: Rik van Riel <riel@surriel.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Yang Shi <shy828301@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
-rw-r--r-- | mm/gup.c | 44 |
1 files changed, 26 insertions, 18 deletions
@@ -501,19 +501,27 @@ static inline void mm_set_has_pinned_flag(unsigned long *mm_flags) #ifdef CONFIG_MMU static struct page *no_page_table(struct vm_area_struct *vma, - unsigned int flags) + unsigned int flags, unsigned long address) { + if (!(flags & FOLL_DUMP)) + return NULL; + /* - * When core dumping an enormous anonymous area that nobody - * has touched so far, we don't want to allocate unnecessary pages or + * When core dumping, we don't want to allocate unnecessary pages or * page tables. Return error instead of NULL to skip handle_mm_fault, * then get_dump_page() will return NULL to leave a hole in the dump. * But we can only make this optimization where a hole would surely * be zero-filled if handle_mm_fault() actually did handle it. */ - if ((flags & FOLL_DUMP) && - (vma_is_anonymous(vma) || !vma->vm_ops->fault)) + if (is_vm_hugetlb_page(vma)) { + struct hstate *h = hstate_vma(vma); + + if (!hugetlbfs_pagecache_present(h, vma, address)) + return ERR_PTR(-EFAULT); + } else if ((vma_is_anonymous(vma) || !vma->vm_ops->fault)) { return ERR_PTR(-EFAULT); + } + return NULL; } @@ -593,7 +601,7 @@ static struct page *follow_page_pte(struct vm_area_struct *vma, ptep = pte_offset_map_lock(mm, pmd, address, &ptl); if (!ptep) - return no_page_table(vma, flags); + return no_page_table(vma, flags, address); pte = ptep_get(ptep); if (!pte_present(pte)) goto no_page; @@ -685,7 +693,7 @@ no_page: pte_unmap_unlock(ptep, ptl); if (!pte_none(pte)) return NULL; - return no_page_table(vma, flags); + return no_page_table(vma, flags, address); } static struct page *follow_pmd_mask(struct vm_area_struct *vma, @@ -701,27 +709,27 @@ static struct page *follow_pmd_mask(struct vm_area_struct *vma, pmd = pmd_offset(pudp, address); pmdval = pmdp_get_lockless(pmd); if (pmd_none(pmdval)) - return no_page_table(vma, flags); + return no_page_table(vma, flags, address); if (!pmd_present(pmdval)) - return no_page_table(vma, flags); + return no_page_table(vma, flags, address); if (pmd_devmap(pmdval)) { ptl = pmd_lock(mm, pmd); page = follow_devmap_pmd(vma, address, pmd, flags, &ctx->pgmap); spin_unlock(ptl); if (page) return page; - return no_page_table(vma, flags); + return no_page_table(vma, flags, address); } if (likely(!pmd_trans_huge(pmdval))) return follow_page_pte(vma, address, pmd, flags, &ctx->pgmap); if (pmd_protnone(pmdval) && !gup_can_follow_protnone(vma, flags)) - return no_page_table(vma, flags); + return no_page_table(vma, flags, address); ptl = pmd_lock(mm, pmd); if (unlikely(!pmd_present(*pmd))) { spin_unlock(ptl); - return no_page_table(vma, flags); + return no_page_table(vma, flags, address); } if (unlikely(!pmd_trans_huge(*pmd))) { spin_unlock(ptl); @@ -752,17 +760,17 @@ static struct page *follow_pud_mask(struct vm_area_struct *vma, pud = pud_offset(p4dp, address); if (pud_none(*pud)) - return no_page_table(vma, flags); + return no_page_table(vma, flags, address); if (pud_devmap(*pud)) { ptl = pud_lock(mm, pud); page = follow_devmap_pud(vma, address, pud, flags, &ctx->pgmap); spin_unlock(ptl); if (page) return page; - return no_page_table(vma, flags); + return no_page_table(vma, flags, address); } if (unlikely(pud_bad(*pud))) - return no_page_table(vma, flags); + return no_page_table(vma, flags, address); return follow_pmd_mask(vma, address, pud, flags, ctx); } @@ -777,10 +785,10 @@ static struct page *follow_p4d_mask(struct vm_area_struct *vma, p4dp = p4d_offset(pgdp, address); p4d = READ_ONCE(*p4dp); if (!p4d_present(p4d)) - return no_page_table(vma, flags); + return no_page_table(vma, flags, address); BUILD_BUG_ON(p4d_leaf(p4d)); if (unlikely(p4d_bad(p4d))) - return no_page_table(vma, flags); + return no_page_table(vma, flags, address); return follow_pud_mask(vma, address, p4dp, flags, ctx); } @@ -830,7 +838,7 @@ static struct page *follow_page_mask(struct vm_area_struct *vma, pgd = pgd_offset(mm, address); if (pgd_none(*pgd) || unlikely(pgd_bad(*pgd))) - return no_page_table(vma, flags); + return no_page_table(vma, flags, address); return follow_p4d_mask(vma, address, pgd, flags, ctx); } |