aboutsummaryrefslogtreecommitdiff
path: root/arch/riscv/include/asm/pgtable.h
diff options
context:
space:
mode:
authorStefan O'Rear <sorear2@gmail.com>2018-12-16 13:03:36 -0500
committerPalmer Dabbelt <palmer@sifive.com>2019-02-11 15:24:45 -0800
commite3613bb8afc2a9474c9214d65c8326c5ac02135e (patch)
tree0d6154dd8b888012626472436e12cc33da1565d9 /arch/riscv/include/asm/pgtable.h
parentd13937116f1e82bf508a6325111b322c30c85eb9 (diff)
downloadlinux-e3613bb8afc2a9474c9214d65c8326c5ac02135e.tar.gz
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.h')
-rw-r--r--arch/riscv/include/asm/pgtable.h8
1 files changed, 4 insertions, 4 deletions
diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h
index 16301966d65b..a8179a8c1491 100644
--- a/arch/riscv/include/asm/pgtable.h
+++ b/arch/riscv/include/asm/pgtable.h
@@ -44,7 +44,7 @@
/* Page protection bits */
#define _PAGE_BASE (_PAGE_PRESENT | _PAGE_ACCESSED | _PAGE_USER)
-#define PAGE_NONE __pgprot(0)
+#define PAGE_NONE __pgprot(_PAGE_PROT_NONE)
#define PAGE_READ __pgprot(_PAGE_BASE | _PAGE_READ)
#define PAGE_WRITE __pgprot(_PAGE_BASE | _PAGE_READ | _PAGE_WRITE)
#define PAGE_EXEC __pgprot(_PAGE_BASE | _PAGE_EXEC)
@@ -98,7 +98,7 @@ extern unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)];
static inline int pmd_present(pmd_t pmd)
{
- return (pmd_val(pmd) & _PAGE_PRESENT);
+ return (pmd_val(pmd) & (_PAGE_PRESENT | _PAGE_PROT_NONE));
}
static inline int pmd_none(pmd_t pmd)
@@ -178,7 +178,7 @@ static inline pte_t *pte_offset_kernel(pmd_t *pmd, unsigned long addr)
static inline int pte_present(pte_t pte)
{
- return (pte_val(pte) & _PAGE_PRESENT);
+ return (pte_val(pte) & (_PAGE_PRESENT | _PAGE_PROT_NONE));
}
static inline int pte_none(pte_t pte)
@@ -380,7 +380,7 @@ static inline int ptep_clear_flush_young(struct vm_area_struct *vma,
*
* Format of swap PTE:
* bit 0: _PAGE_PRESENT (zero)
- * bit 1: reserved for future use (zero)
+ * bit 1: _PAGE_PROT_NONE (zero)
* bits 2 to 6: swap type
* bits 7 to XLEN-1: swap offset
*/