MIPS: mm: fixed mappings: correct initialisation

[ Upstream commit 71eb989a ]

fixrange_init operates at PMD-granularity and expects the addresses to
be PMD-size aligned, but currently that might not be the case for
PKMAP_BASE unless it is defined properly, so ensure a correct alignment
is used before passing the address to fixrange_init.

fixed mappings: only align the start address that is passed to
fixrange_init rather than the value before adding the size, as we may
end up with uninitialised upper part of the range.
Signed-off-by: Marcin Nowakowski <marcin.nowakowski@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/15948/Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

arch/mips/mm/pgtable-32.c

@@ -51,15 +51,15 @@ void __init pagetable_init(void)
 	/*
 	 * Fixed mappings:
 	 */
-	vaddr = __fix_to_virt(__end_of_fixed_addresses - 1) & PMD_MASK;
-	fixrange_init(vaddr, vaddr + FIXADDR_SIZE, pgd_base);
+	vaddr = __fix_to_virt(__end_of_fixed_addresses - 1);
+	fixrange_init(vaddr & PMD_MASK, vaddr + FIXADDR_SIZE, pgd_base);
 
 #ifdef CONFIG_HIGHMEM
 	/*
 	 * Permanent kmaps:
 	 */
 	vaddr = PKMAP_BASE;
-	fixrange_init(vaddr, vaddr + PAGE_SIZE*LAST_PKMAP, pgd_base);
+	fixrange_init(vaddr & PMD_MASK, vaddr + PAGE_SIZE*LAST_PKMAP, pgd_base);
 
 	pgd = swapper_pg_dir + __pgd_offset(vaddr);
 	pud = pud_offset(pgd, vaddr);