From mboxrd@z Thu Jan 1 00:00:00 1970 From: dserrg@gmail.com (Sergey Dyasly) Date: Thu, 27 Jun 2013 21:24:35 +0400 Subject: [PATCH] ARM: LPAE: don't reject mapping /dev/mem above 4GB Message-ID: <1372353875-3262-1-git-send-email-dserrg@gmail.com> To: linux-arm-kernel@lists.infradead.org List-Id: linux-arm-kernel.lists.infradead.org With LPAE enabled, physical address space is larger than 4GB. Allow mapping any part of it via /dev/mem by utilizing the same check as in arm64. Reported-by: Vassili Karpov Tested-by: Vassili Karpov Signed-off-by: Sergey Dyasly --- arch/arm/mm/mmap.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/arch/arm/mm/mmap.c b/arch/arm/mm/mmap.c index 10062ce..8f1bbbc 100644 --- a/arch/arm/mm/mmap.c +++ b/arch/arm/mm/mmap.c @@ -203,6 +203,15 @@ int valid_phys_addr_range(phys_addr_t addr, size_t size) return 1; } +#ifdef CONFIG_ARM_LPAE +/* + * 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 << PAGE_SHIFT) + size) & ~PHYS_MASK); +} +#else /* * 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 @@ -212,6 +221,7 @@ int valid_mmap_phys_addr_range(unsigned long pfn, size_t size) { return !(pfn + (size >> PAGE_SHIFT) > 0x00100000); } +#endif #ifdef CONFIG_STRICT_DEVMEM -- 1.8.1.2