3.12-stable review patch. If anyone has any objections, please let me know.
------------------
From: Catalin Marinas <catalin.marinas@xxxxxxx>
commit 3676f9ef5481d614f8c5c857f5319755be248268 upstream.
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
59911ca4325d (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@xxxxxxxxxx>
Signed-off-by: Catalin Marinas <catalin.marinas@xxxxxxx>
Tested-by: Steve Capper <steve.capper@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
arch/arm64/include/asm/pgtable.h | 31 +++++++++++++++++--------------
1 file changed, 17 insertions(+), 14 deletions(-)
--- a/arch/arm64/include/asm/pgtable.h
+++ b/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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