From: Sergey Dyasly <[email protected]> 3.12-stable review patch. If anyone has any objections, please let me know.
=============== commit 3159f372354e8e1f5dee714663d705dd2c7e0759 upstream. With LPAE enabled, physical address space is larger than 4GB. Allow mapping any part of it via /dev/mem by using PHYS_MASK to determine valid range. PHYS_MASK covers 40 bits with LPAE enabled and 32 bits otherwise. Reported-by: Vassili Karpov <[email protected]> Signed-off-by: Sergey Dyasly <[email protected]> Acked-by: Catalin Marinas <[email protected]> Signed-off-by: Russell King <[email protected]> Signed-off-by: Jiri Slaby <[email protected]> --- arch/arm/mm/mmap.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) diff --git a/arch/arm/mm/mmap.c b/arch/arm/mm/mmap.c index 304661d21369..5e85ed371364 100644 --- a/arch/arm/mm/mmap.c +++ b/arch/arm/mm/mmap.c @@ -202,13 +202,11 @@ int valid_phys_addr_range(phys_addr_t addr, size_t size) } /* - * We don't use supersection mappings for mmap() on /dev/mem, which - * means that we can't map the memory area above the 4G barrier into - * userspace. + * Do not allow /dev/mem mappings beyond the supported physical range. */ int valid_mmap_phys_addr_range(unsigned long pfn, size_t size) { - return !(pfn + (size >> PAGE_SHIFT) > 0x00100000); + return (pfn + (size >> PAGE_SHIFT)) <= (1 + (PHYS_MASK >> PAGE_SHIFT)); } #ifdef CONFIG_STRICT_DEVMEM -- 1.9.2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
