for OUTPUT device, it will map the page as VM_WRITE
and for INPUT device, it will map the page as
VM_READ. mmap will check the if the prot
is matched with the device type, but not only
check VM_WRITE.
This is actually synced from videobuf2.
Signed-off-by: Kassey Lee <ygli@xxxxxxxxxxx>
hi, Guennadi:
how about sync this enhencement from videbuf2 to videbuf when MMAP is used ?
---
drivers/media/video/videobuf-core.c | 18 ++++++++++++++++--
1 files changed, 16 insertions(+), 2 deletions(-)
diff --git a/drivers/media/video/videobuf-core.c b/drivers/media/video/videobuf-core.c
index de4fa4e..202dd5d 100644
--- a/drivers/media/video/videobuf-core.c
+++ b/drivers/media/video/videobuf-core.c
@@ -1182,10 +1182,24 @@ int videobuf_mmap_mapper(struct videobuf_queue *q, struct vm_area_struct *vma)
MAGIC_CHECK(q->int_ops->magic, MAGIC_QTYPE_OPS);
- if (!(vma->vm_flags & VM_WRITE) || !(vma->vm_flags & VM_SHARED)) {
- dprintk(1, "mmap appl bug: PROT_WRITE and MAP_SHARED are required\n");
+ /*
+ * Check memory area access mode.
+ */
+ if (!(vma->vm_flags & VM_SHARED)) {
+ dprintk(1, "Invalid vma flags, VM_SHARED needed\n");
return -EINVAL;
}
+ if (V4L2_TYPE_IS_OUTPUT(q->type)) {
+ if (!(vma->vm_flags & VM_WRITE)) {
+ dprintk(1, "Invalid vma flags, VM_WRITE needed\n");
+ return -EINVAL;
+ }
+ } else {
+ if (!(vma->vm_flags & VM_READ)) {
+ dprintk(1, "Invalid vma flags, VM_READ needed\n");
+ return -EINVAL;
+ }
+ }
videobuf_queue_lock(q);
for (i = 0; i < VIDEO_MAX_FRAME; i++) {
--
1.7.4.1
--
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