ARM: 7931/1: Correct virt_addr_valid

commit efea3403d4b7c6d1dd5d5ac3234c161e8b314d66 upstream.

The definition of virt_addr_valid is that virt_addr_valid should
return true if and only if virt_to_page returns a valid pointer.
The current definition of virt_addr_valid only checks against the
virtual address range. There's no guarantee that just because a
virtual address falls bewteen PAGE_OFFSET and high_memory the
associated physical memory has a valid backing struct page. Follow
the example of other architectures and convert to pfn_valid to
verify that the virtual address is actually valid. The check for
an address between PAGE_OFFSET and high_memory is still necessary
as vmalloc/highmem addresses are not valid with virt_to_page.

Cc: Will Deacon <will.deacon@arm.com>
Cc: Nicolas Pitre <nico@linaro.org>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Laura Abbott <lauraa@codeaurora.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Jiri Slaby <jslaby@suse.cz>

diff --git a/arch/arm/include/asm/memory.h b/arch/arm/include/asm/memory.h
index e750a938fd3ce283ccd351cb73ed9c3d8df84e75..152b8e67f8b8b5827477a451f080f3cdaf2e0c7e 100644 (file)
--- a/arch/arm/include/asm/memory.h
+++ b/arch/arm/include/asm/memory.h
@@ -285,7 +285,8 @@ static inline __deprecated void *bus_to_virt(unsigned long x)
 #define ARCH_PFN_OFFSET                PHYS_PFN_OFFSET
 
 #define virt_to_page(kaddr)    pfn_to_page(__pa(kaddr) >> PAGE_SHIFT)
-#define virt_addr_valid(kaddr) ((unsigned long)(kaddr) >= PAGE_OFFSET && (unsigned long)(kaddr) < (unsigned long)high_memory)
+#define virt_addr_valid(kaddr) (((unsigned long)(kaddr) >= PAGE_OFFSET && (unsigned long)(kaddr) < (unsigned long)high_memory) \
+                                       && pfn_valid(__pa(kaddr) >> PAGE_SHIFT) )
 
 #endif