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| author | Stefan O'Rear <sorear2@gmail.com> | 2018-12-16 13:03:36 -0500 |
|---|---|---|
| committer | Palmer Dabbelt <palmer@sifive.com> | 2019-02-11 15:24:45 -0800 |
| commit | e3613bb8afc2a9474c9214d65c8326c5ac02135e (patch) | |
| tree | 0d6154dd8b888012626472436e12cc33da1565d9 /arch/riscv/include/asm/pgtable-bits.h | |
| parent | d13937116f1e82bf508a6325111b322c30c85eb9 (diff) | |
| download | linux-0-day-e3613bb8afc2a9474c9214d65c8326c5ac02135e.tar.gz linux-0-day-e3613bb8afc2a9474c9214d65c8326c5ac02135e.tar.xz | |
riscv: Add pte bit to distinguish swap from invalid
Previously, invalid PTEs and swap PTEs had the same binary
representation, causing errors when attempting to unmap PROT_NONE
mappings, including implicit unmap on exit.
Typical error:
swap_info_get: Bad swap file entry 40000000007a9879
BUG: Bad page map in process a.out pte:3d4c3cc0 pmd:3e521401
Cc: stable@vger.kernel.org
Signed-off-by: Stefan O'Rear <sorear2@gmail.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Palmer Dabbelt <palmer@sifive.com>
Diffstat (limited to 'arch/riscv/include/asm/pgtable-bits.h')
| -rw-r--r-- | arch/riscv/include/asm/pgtable-bits.h | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/arch/riscv/include/asm/pgtable-bits.h b/arch/riscv/include/asm/pgtable-bits.h index 2fa2942be221e..470755cb75584 100644 --- a/arch/riscv/include/asm/pgtable-bits.h +++ b/arch/riscv/include/asm/pgtable-bits.h @@ -35,6 +35,12 @@ #define _PAGE_SPECIAL _PAGE_SOFT #define _PAGE_TABLE _PAGE_PRESENT +/* + * _PAGE_PROT_NONE is set on not-present pages (and ignored by the hardware) to + * distinguish them from swapped out pages + */ +#define _PAGE_PROT_NONE _PAGE_READ + #define _PAGE_PFN_SHIFT 10 /* Set of bits to preserve across pte_modify() */ |