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| author | Dave Airlie <airlied@redhat.com> | 2017-06-27 07:24:49 +1000 |
|---|---|---|
| committer | Dave Airlie <airlied@redhat.com> | 2017-06-27 08:28:30 +1000 |
| commit | 6d61e70ccc21606ffb8a0a03bd3aba24f659502b (patch) | |
| tree | 69f5bfb29d085cc42839445d34170bd3ee4f7408 /mm/vmalloc.c | |
| parent | 338ffbf7cb5eee0ed4600650d03cd2d7cd1cac9d (diff) | |
| parent | c0bc126f97fb929b3ae02c1c62322645d70eb408 (diff) | |
Backmerge tag 'v4.12-rc7' into drm-next
Linux 4.12-rc7
Needed at least rc6 for drm-misc-next-fixes, may as well go to rc7
Diffstat (limited to 'mm/vmalloc.c')
| -rw-r--r-- | mm/vmalloc.c | 15 |
1 files changed, 13 insertions, 2 deletions
diff --git a/mm/vmalloc.c b/mm/vmalloc.c index 34a1c3e46ed7..ecc97f74ab18 100644 --- a/mm/vmalloc.c +++ b/mm/vmalloc.c @@ -287,10 +287,21 @@ struct page *vmalloc_to_page(const void *vmalloc_addr) if (p4d_none(*p4d)) return NULL; pud = pud_offset(p4d, addr); - if (pud_none(*pud)) + + /* + * Don't dereference bad PUD or PMD (below) entries. This will also + * identify huge mappings, which we may encounter on architectures + * that define CONFIG_HAVE_ARCH_HUGE_VMAP=y. Such regions will be + * identified as vmalloc addresses by is_vmalloc_addr(), but are + * not [unambiguously] associated with a struct page, so there is + * no correct value to return for them. + */ + WARN_ON_ONCE(pud_bad(*pud)); + if (pud_none(*pud) || pud_bad(*pud)) return NULL; pmd = pmd_offset(pud, addr); - if (pmd_none(*pmd)) + WARN_ON_ONCE(pmd_bad(*pmd)); + if (pmd_none(*pmd) || pmd_bad(*pmd)) return NULL; ptep = pte_offset_map(pmd, addr); |