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arm64: Move PTE_PROT_NONE higher up

PTE_PROT_NONE means that a pte is present but does not have any
read/write attributes. However, setting the memory type like
pgprot_writecombine() is allowed and such bits overlap with
PTE_PROT_NONE. This causes mmap/munmap issues in drivers that change the
vma->vm_pg_prot on PROT_NONE mappings.

This patch reverts the PTE_FILE/PTE_PROT_NONE shift in commit
59911ca432 (ARM64: mm: Move PTE_PROT_NONE bit) and moves PTE_PROT_NONE
together with the other software bits.

Signed-off-by: Steve Capper <steve.capper@linaro.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Tested-by: Steve Capper <steve.capper@linaro.org>
Cc: <stable@vger.kernel.org> # 3.11+
master
Catalin Marinas 8 years ago
parent
commit
3676f9ef54
  1. 31
      arch/arm64/include/asm/pgtable.h

31
arch/arm64/include/asm/pgtable.h

@ -25,10 +25,11 @@
* Software defined PTE bits definition.
*/
#define PTE_VALID (_AT(pteval_t, 1) << 0)
#define PTE_PROT_NONE (_AT(pteval_t, 1) << 2) /* only when !PTE_VALID */
#define PTE_FILE (_AT(pteval_t, 1) << 3) /* only when !pte_present() */
#define PTE_FILE (_AT(pteval_t, 1) << 2) /* only when !pte_present() */
#define PTE_DIRTY (_AT(pteval_t, 1) << 55)
#define PTE_SPECIAL (_AT(pteval_t, 1) << 56)
/* bit 57 for PMD_SECT_SPLITTING */
#define PTE_PROT_NONE (_AT(pteval_t, 1) << 58) /* only when !PTE_VALID */
/*
* VMALLOC and SPARSEMEM_VMEMMAP ranges.
@ -357,18 +358,20 @@ extern pgd_t idmap_pg_dir[PTRS_PER_PGD];
/*
* Encode and decode a swap entry:
* bits 0, 2: present (must both be zero)
* bit 3: PTE_FILE
* bits 4-8: swap type
* bits 9-63: swap offset
* bits 0-1: present (must be zero)
* bit 2: PTE_FILE
* bits 3-8: swap type
* bits 9-57: swap offset
*/
#define __SWP_TYPE_SHIFT 4
#define __SWP_TYPE_SHIFT 3
#define __SWP_TYPE_BITS 6
#define __SWP_OFFSET_BITS 49
#define __SWP_TYPE_MASK ((1 << __SWP_TYPE_BITS) - 1)
#define __SWP_OFFSET_SHIFT (__SWP_TYPE_BITS + __SWP_TYPE_SHIFT)
#define __SWP_OFFSET_MASK ((1UL << __SWP_OFFSET_BITS) - 1)
#define __swp_type(x) (((x).val >> __SWP_TYPE_SHIFT) & __SWP_TYPE_MASK)
#define __swp_offset(x) ((x).val >> __SWP_OFFSET_SHIFT)
#define __swp_offset(x) (((x).val >> __SWP_OFFSET_SHIFT) & __SWP_OFFSET_MASK)
#define __swp_entry(type,offset) ((swp_entry_t) { ((type) << __SWP_TYPE_SHIFT) | ((offset) << __SWP_OFFSET_SHIFT) })
#define __pte_to_swp_entry(pte) ((swp_entry_t) { pte_val(pte) })
@ -382,15 +385,15 @@ extern pgd_t idmap_pg_dir[PTRS_PER_PGD];
/*
* Encode and decode a file entry:
* bits 0, 2: present (must both be zero)
* bit 3: PTE_FILE
* bits 4-63: file offset / PAGE_SIZE
* bits 0-1: present (must be zero)
* bit 2: PTE_FILE
* bits 3-57: file offset / PAGE_SIZE
*/
#define pte_file(pte) (pte_val(pte) & PTE_FILE)
#define pte_to_pgoff(x) (pte_val(x) >> 4)
#define pgoff_to_pte(x) __pte(((x) << 4) | PTE_FILE)
#define pte_to_pgoff(x) (pte_val(x) >> 3)
#define pgoff_to_pte(x) __pte(((x) << 3) | PTE_FILE)
#define PTE_FILE_MAX_BITS 60
#define PTE_FILE_MAX_BITS 55
extern int kern_addr_valid(unsigned long addr);

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