Commit 3676f9ef authored by Catalin Marinas's avatar Catalin Marinas
Browse files

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
59911ca4 (ARM64: mm: Move PTE_PROT_NONE bit) and moves PTE_PROT_NONE
together with the other software bits.

Signed-off-by: default avatarSteve Capper <steve.capper@linaro.org>
Signed-off-by: default avatarCatalin Marinas <catalin.marinas@arm.com>
Tested-by: default avatarSteve Capper <steve.capper@linaro.org>
Cc: <stable@vger.kernel.org> # 3.11+
parent 4f00130b

arch/arm64/include/asm/pgtable.h

+17 −14
Original line number Diff line number Diff line
@@ -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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