diff options
| -rw-r--r-- | arch/x86/include/asm/io.h | 4 | ||||
| -rw-r--r-- | arch/x86/mm/mmap.c | 16 | ||||
| -rw-r--r-- | drivers/char/mem.c | 4 |
3 files changed, 24 insertions, 0 deletions
diff --git a/arch/x86/include/asm/io.h b/arch/x86/include/asm/io.h index 93ae8aee1780..95e948627fd0 100644 --- a/arch/x86/include/asm/io.h +++ b/arch/x86/include/asm/io.h @@ -111,6 +111,10 @@ build_mmio_write(__writeq, "q", unsigned long, "r", ) #endif +#define ARCH_HAS_VALID_PHYS_ADDR_RANGE +extern int valid_phys_addr_range(phys_addr_t addr, size_t size); +extern int valid_mmap_phys_addr_range(unsigned long pfn, size_t size); + /** * virt_to_phys - map virtual addresses to physical * @address: address to remap diff --git a/arch/x86/mm/mmap.c b/arch/x86/mm/mmap.c index 62285fe77b0f..155ecbac9e28 100644 --- a/arch/x86/mm/mmap.c +++ b/arch/x86/mm/mmap.c @@ -33,6 +33,8 @@ #include <linux/compat.h> #include <asm/elf.h> +#include "physaddr.h" + struct va_alignment __read_mostly va_align = { .flags = -1, }; @@ -220,3 +222,17 @@ bool mmap_address_hint_valid(unsigned long addr, unsigned long len) return (addr > DEFAULT_MAP_WINDOW) == (addr + len > DEFAULT_MAP_WINDOW); } + +/* Can we access it for direct reading/writing? Must be RAM: */ +int valid_phys_addr_range(phys_addr_t addr, size_t count) +{ + return addr + count <= __pa(high_memory); +} + +/* Can we access it through mmap? Must be a valid physical address: */ +int valid_mmap_phys_addr_range(unsigned long pfn, size_t count) +{ + phys_addr_t addr = (phys_addr_t)pfn << PAGE_SHIFT; + + return phys_addr_valid(addr + count - 1); +} diff --git a/drivers/char/mem.c b/drivers/char/mem.c index 970e1242a282..6aefe5370e5b 100644 --- a/drivers/char/mem.c +++ b/drivers/char/mem.c @@ -343,6 +343,10 @@ static int mmap_mem(struct file *file, struct vm_area_struct *vma) size_t size = vma->vm_end - vma->vm_start; phys_addr_t offset = (phys_addr_t)vma->vm_pgoff << PAGE_SHIFT; + /* Does it even fit in phys_addr_t? */ + if (offset >> PAGE_SHIFT != vma->vm_pgoff) + return -EINVAL; + /* It's illegal to wrap around the end of the physical address space. */ if (offset + (phys_addr_t)size - 1 < offset) return -EINVAL; |