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mm/gup: handle hugetlb for no_page_table()

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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>
This commit is contained in:
Peter Xu 2024-03-27 11:23:27 -04:00 committed by Andrew Morton
parent f3c94c625f
commit 878b0c4516
1 changed files with 26 additions and 18 deletions
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44
mm/gup.c
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@ -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);
}