omap: iovmm: disallow mapping NULL address when IOVMF_DA_ANON is set

commit c7f4ab26e3bcdaeb3e19ec658e3ad9092f1a6ceb allowed mapping the NULL
address if da_start==0, which would then not get unmapped. Disallow
this again if IOVMF_DA_ANON is set. And spell variable 'alignment'
correctly.

Signed-off-by: Michael Jones <michael.jones@matrix-vision.de>
Signed-off-by: Tony Lindgren <tony@atomide.com>

1 files changed, 7 insertions, 6 deletions

diff --git a/arch/arm/plat-omap/iovmm.c b/arch/arm/plat-omap/iovmm.c
index 6dc1296c8c77..ea7eab98a736 100644
--- a/arch/arm/plat-omap/iovmm.c
+++ b/arch/arm/plat-omap/iovmm.c
@@ -271,20 +271,21 @@ static struct iovm_struct *alloc_iovm_area(struct iommu *obj, u32 da,
                                            size_t bytes, u32 flags)
 {
         struct iovm_struct *new, *tmp;
-        u32 start, prev_end, alignement;
+        u32 start, prev_end, alignment;
 
         if (!obj || !bytes)
                 return ERR_PTR(-EINVAL);
 
         start = da;
-        alignement = PAGE_SIZE;
+        alignment = PAGE_SIZE;
 
         if (flags & IOVMF_DA_ANON) {
-                start = obj->da_start;
+                /* Don't map address 0 */
+                start = obj->da_start ? obj->da_start : alignment;
 
                 if (flags & IOVMF_LINEAR)
-                        alignement = iopgsz_max(bytes);
-                start = roundup(start, alignement);
+                        alignment = iopgsz_max(bytes);
+                start = roundup(start, alignment);
         } else if (start < obj->da_start || start > obj->da_end ||
                                         obj->da_end - start < bytes) {
                 return ERR_PTR(-EINVAL);
@@ -304,7 +305,7 @@ static struct iovm_struct *alloc_iovm_area(struct iommu *obj, u32 da,
                         goto found;
 
                 if (tmp->da_end >= start && flags & IOVMF_DA_ANON)
-                        start = roundup(tmp->da_end + 1, alignement);
+                        start = roundup(tmp->da_end + 1, alignment);
 
                 prev_end = tmp->da_end;
         }