diff options
Diffstat (limited to 'arch/arm64/mm/mmap.c')
| -rw-r--r-- | arch/arm64/mm/mmap.c | 19 |
1 files changed, 13 insertions, 6 deletions
diff --git a/arch/arm64/mm/mmap.c b/arch/arm64/mm/mmap.c index 7b0d55756eb1..adc208c2ae9c 100644 --- a/arch/arm64/mm/mmap.c +++ b/arch/arm64/mm/mmap.c @@ -18,6 +18,7 @@ #include <linux/elf.h> #include <linux/fs.h> +#include <linux/memblock.h> #include <linux/mm.h> #include <linux/mman.h> #include <linux/export.h> @@ -103,12 +104,18 @@ void arch_pick_mmap_layout(struct mm_struct *mm) */ int valid_phys_addr_range(phys_addr_t addr, size_t size) { - if (addr < PHYS_OFFSET) - return 0; - if (addr + size > __pa(high_memory - 1) + 1) - return 0; - - return 1; + /* + * Check whether addr is covered by a memory region without the + * MEMBLOCK_NOMAP attribute, and whether that region covers the + * entire range. In theory, this could lead to false negatives + * if the range is covered by distinct but adjacent memory regions + * that only differ in other attributes. However, few of such + * attributes have been defined, and it is debatable whether it + * follows that /dev/mem read() calls should be able traverse + * such boundaries. + */ + return memblock_is_region_memory(addr, size) && + memblock_is_map_memory(addr); } /* |