[PATCH] powerpc: IOMMU: don't ioremap null addresses
240-ioremap-null-ptr-test.patch
Under highly unusual circumstances, a buggy driver will ask a null ptr
to be ioremapped, an operation that curently succeeds but leads to
later trouble. Instead, refuse to remap the null pointer.
Signed-off-by: Linas Vepstas <linas@austin.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
(cherry picked from e71d9e598533c1889e7162f5f4647e5d378c102c commit)
diff --git a/arch/powerpc/mm/pgtable_64.c b/arch/powerpc/mm/pgtable_64.c
index 2ffca63..7b278d83 100644
--- a/arch/powerpc/mm/pgtable_64.c
+++ b/arch/powerpc/mm/pgtable_64.c
@@ -174,7 +174,7 @@
pa = addr & PAGE_MASK;
size = PAGE_ALIGN(addr + size) - pa;
- if (size == 0)
+ if ((size == 0) || (pa == 0))
return NULL;
if (mem_init_done) {