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| author | Sergey Dyasly <dserrg@gmail.com> | 2013-09-24 16:38:00 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2014-05-13 13:59:41 +0200 |
| commit | b6b461e90f8fbebb8fa46f363999ed5023be7d3c (patch) | |
| tree | f1c57d2f39278100b4329d249c37877d3d55c965 | |
| parent | d306606e58d53a9d8cd78fefacbe9a50b3aa9fcd (diff) | |
| download | lwn-b6b461e90f8fbebb8fa46f363999ed5023be7d3c.tar.gz lwn-b6b461e90f8fbebb8fa46f363999ed5023be7d3c.zip | |
ARM: 7840/1: LPAE: don't reject mapping /dev/mem above 4GB
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 <av1474@comtv.ru>
Signed-off-by: Sergey Dyasly <dserrg@gmail.com>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Cc: hujianyang <hujianyang@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | arch/arm/mm/mmap.c | 6 |
1 files changed, 2 insertions, 4 deletions
diff --git a/arch/arm/mm/mmap.c b/arch/arm/mm/mmap.c index f0ef2f7d4ad7..5ef506c6f492 100644 --- a/arch/arm/mm/mmap.c +++ b/arch/arm/mm/mmap.c @@ -204,13 +204,11 @@ 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 |