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| author |   Matthew Wilcox (Oracle) <willy@infradead.org> | 2022-01-07 13:25:55 -0500 |
|---|---|---|
| committer | Matthew Wilcox (Oracle) <willy@infradead.org> | 2022-03-21 12:56:35 -0400 |
| commit | c228afb11ac6938532703ac712992524497aff29 (patch) | |
| tree | 2bf4703ab380845339879cd50456e62d8964ed6a /mm/gup.c | |
| parent | mm/gup: Change the calling convention for compound_next() (diff) | |
| download | linux-dev-c228afb11ac6938532703ac712992524497aff29.tar.xz linux-dev-c228afb11ac6938532703ac712992524497aff29.zip | |
mm/gup: Fix some contiguous memmap assumptions
Several functions in gup.c assume that a compound page has virtually
contiguous page structs. This isn't true for SPARSEMEM configs unless
SPARSEMEM_VMEMMAP is also set. Fix them by using nth_page() instead of
plain pointer arithmetic.
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: William Kucharski <william.kucharski@oracle.com>
Diffstat (limited to 'mm/gup.c')
| -rw-r--r-- | mm/gup.c | 14 |
1 files changed, 7 insertions, 7 deletions
@@ -258,7 +258,7 @@ static inline struct page *compound_range_next(struct page *start, struct page *next, *page; unsigned int nr = 1; - next = start + i; + next = nth_page(start, i); page = compound_head(next); if (PageHead(page)) nr = min_t(unsigned int, @@ -2440,8 +2440,8 @@ static int record_subpages(struct page *page, unsigned long addr, { int nr; - for (nr = 0; addr != end; addr += PAGE_SIZE) - pages[nr++] = page++; + for (nr = 0; addr != end; nr++, addr += PAGE_SIZE) + pages[nr] = nth_page(page, nr); return nr; } @@ -2476,7 +2476,7 @@ static int gup_hugepte(pte_t *ptep, unsigned long sz, unsigned long addr, VM_BUG_ON(!pfn_valid(pte_pfn(pte))); head = pte_page(pte); - page = head + ((addr & (sz-1)) >> PAGE_SHIFT); + page = nth_page(head, (addr & (sz - 1)) >> PAGE_SHIFT); refs = record_subpages(page, addr, end, pages + *nr); head = try_grab_compound_head(head, refs, flags); @@ -2536,7 +2536,7 @@ static int gup_huge_pmd(pmd_t orig, pmd_t *pmdp, unsigned long addr, pages, nr); } - page = pmd_page(orig) + ((addr & ~PMD_MASK) >> PAGE_SHIFT); + page = nth_page(pmd_page(orig), (addr & ~PMD_MASK) >> PAGE_SHIFT); refs = record_subpages(page, addr, end, pages + *nr); head = try_grab_compound_head(pmd_page(orig), refs, flags); @@ -2570,7 +2570,7 @@ static int gup_huge_pud(pud_t orig, pud_t *pudp, unsigned long addr, pages, nr); } - page = pud_page(orig) + ((addr & ~PUD_MASK) >> PAGE_SHIFT); + page = nth_page(pud_page(orig), (addr & ~PUD_MASK) >> PAGE_SHIFT); refs = record_subpages(page, addr, end, pages + *nr); head = try_grab_compound_head(pud_page(orig), refs, flags); @@ -2599,7 +2599,7 @@ static int gup_huge_pgd(pgd_t orig, pgd_t *pgdp, unsigned long addr, BUILD_BUG_ON(pgd_devmap(orig)); - page = pgd_page(orig) + ((addr & ~PGDIR_MASK) >> PAGE_SHIFT); + page = nth_page(pgd_page(orig), (addr & ~PGDIR_MASK) >> PAGE_SHIFT); refs = record_subpages(page, addr, end, pages + *nr); head = try_grab_compound_head(pgd_page(orig), refs, flags); |