arm64: Ensure pmd_present() returns false after pmd_mknotpresent()

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commit 5bb1cc0ff9 upstream.

Currently, pmd_present() only checks for a non-zero value, returning
true even after pmd_mknotpresent() (which only clears the type bits).
This patch converts pmd_present() to using pte_present(), similar to the
other pmd_*() checks. As a side effect, it will return true for
PROT_NONE mappings, though they are not yet used by the kernel with
transparent huge pages.

For consistency, also change pmd_mknotpresent() to only clear the
PMD_SECT_VALID bit, even though the PMD_TABLE_BIT is already 0 for block
mappings (no functional change). The unused PMD_SECT_PROT_NONE
definition is removed as transparent huge pages use the pte page prot
values.

Fixes: 9c7e535fcc ("arm64: mm: Route pmd thp functions through pte equivalents")
Reviewed-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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Catalin Marinas 2016-05-05 10:44:02 +01:00 • committed by Greg Kroah-Hartman

parent f07f749170

commit 737b0679fd

2 changed files with 2 additions and 3 deletions

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arch/arm64/include/asm/pgtable-hwdef.h

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4

arch/arm64/include/asm/pgtable.h

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