arm64: Fix for the arm64 kern_addr_valid() function

Fix for the arm64 kern_addr_valid() function to recognize
virtual addresses in the kernel logical memory map.  The
function fails as written because it does not check whether
the addresses in that region are mapped at the pmd level to
2MB or 512MB pages, continues the page table walk to the
pte level, and issues a garbage value to pfn_valid().

Tested on 4K-page and 64K-page kernels.

Signed-off-by: Dave Anderson <anderson@redhat.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c
index 6b7e89569a3a9ff8518e7c6ee856603f1e9fb93b..0a472c41a67fa9dc33e9c746c24a402d6f306289 100644 (file)
--- a/arch/arm64/mm/mmu.c
+++ b/arch/arm64/mm/mmu.c
@@ -374,6 +374,9 @@ int kern_addr_valid(unsigned long addr)
        if (pmd_none(*pmd))
                return 0;
 
+       if (pmd_sect(*pmd))
+               return pfn_valid(pmd_pfn(*pmd));
+
        pte = pte_offset_kernel(pmd, addr);
        if (pte_none(*pte))
                return 0;