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| author | Nicholas Piggin <npiggin@gmail.com> | 2021-12-16 20:33:42 +1000 |
|---|---|---|
| committer | Michael Ellerman <mpe@ellerman.id.au> | 2021-12-20 12:13:32 +1100 |
| commit | 467ba14e1660b52a2f9338b484704c461bd23019 (patch) | |
| tree | 7c68c13ec4aa1c400f4561713f63f4774c30ff28 /arch/powerpc/mm/pgtable_64.c | |
| parent | a605b39e8ef703828b9e26750ea1925a6a5ef848 (diff) | |
| download | linux-467ba14e1660b52a2f9338b484704c461bd23019.tar.gz | |
powerpc/64s/radix: Fix huge vmap false positive
pmd_huge() is defined to false when HUGETLB_PAGE is not configured, but
the vmap code still installs huge PMDs. This leads to false bad PMD
errors when vunmapping because it is not seen as a huge PTE, and the bad
PMD check catches it. The end result may not be much more serious than
some bad pmd warning messages, because the pmd_none_or_clear_bad() does
what we wanted and clears the huge PTE anyway.
Fix this by checking pmd_is_leaf(), which checks for a PTE regardless of
config options. The whole huge/large/leaf stuff is a tangled mess but
that's kernel-wide and not something we can improve much in arch/powerpc
code.
pmd_page(), pud_page(), etc., called by vmalloc_to_page() on huge vmaps
can similarly trigger a false VM_BUG_ON when CONFIG_HUGETLB_PAGE=n, so
those checks are adjusted. The checks were added by commit d6eacedd1f0e
("powerpc/book3s: Use config independent helpers for page table walk"),
while implementing a similar fix for other page table walking functions.
Fixes: d909f9109c30 ("powerpc/64s/radix: Enable HAVE_ARCH_HUGE_VMAP")
Cc: stable@vger.kernel.org # v5.3+
Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20211216103342.609192-1-npiggin@gmail.com
Diffstat (limited to 'arch/powerpc/mm/pgtable_64.c')
| -rw-r--r-- | arch/powerpc/mm/pgtable_64.c | 14 |
1 files changed, 11 insertions, 3 deletions
diff --git a/arch/powerpc/mm/pgtable_64.c b/arch/powerpc/mm/pgtable_64.c index 78c8cf01db5f9..175aabf101e87 100644 --- a/arch/powerpc/mm/pgtable_64.c +++ b/arch/powerpc/mm/pgtable_64.c @@ -102,7 +102,8 @@ EXPORT_SYMBOL(__pte_frag_size_shift); struct page *p4d_page(p4d_t p4d) { if (p4d_is_leaf(p4d)) { - VM_WARN_ON(!p4d_huge(p4d)); + if (!IS_ENABLED(CONFIG_HAVE_ARCH_HUGE_VMAP)) + VM_WARN_ON(!p4d_huge(p4d)); return pte_page(p4d_pte(p4d)); } return virt_to_page(p4d_pgtable(p4d)); @@ -112,7 +113,8 @@ struct page *p4d_page(p4d_t p4d) struct page *pud_page(pud_t pud) { if (pud_is_leaf(pud)) { - VM_WARN_ON(!pud_huge(pud)); + if (!IS_ENABLED(CONFIG_HAVE_ARCH_HUGE_VMAP)) + VM_WARN_ON(!pud_huge(pud)); return pte_page(pud_pte(pud)); } return virt_to_page(pud_pgtable(pud)); @@ -125,7 +127,13 @@ struct page *pud_page(pud_t pud) struct page *pmd_page(pmd_t pmd) { if (pmd_is_leaf(pmd)) { - VM_WARN_ON(!(pmd_large(pmd) || pmd_huge(pmd))); + /* + * vmalloc_to_page may be called on any vmap address (not only + * vmalloc), and it uses pmd_page() etc., when huge vmap is + * enabled so these checks can't be used. + */ + if (!IS_ENABLED(CONFIG_HAVE_ARCH_HUGE_VMAP)) + VM_WARN_ON(!(pmd_large(pmd) || pmd_huge(pmd))); return pte_page(pmd_pte(pmd)); } return virt_to_page(pmd_page_vaddr(pmd)); |