From: David S. Miller <davem@sunset.davemloft.net>
Date: Sat, 24 Dec 2005 20:06:10 +0000 (-0800)
Subject: [VIDEO] sbuslib: Disallow private mmaps.
X-Git-Url: https://git.stricted.de/?a=commitdiff_plain;h=e445ee65cbefaa19131c972ae7fe221c95cf4cc4;p=GitHub%2FLineageOS%2Fandroid_kernel_samsung_universal7580.git

[VIDEO] sbuslib: Disallow private mmaps.

The COW semantics just do not make any sense especially
with the physically discontiguous I/O mappings possible
here.

Signed-off-by: David S. Miller <davem@davemloft.net>
---

diff --git a/drivers/video/sbuslib.c b/drivers/video/sbuslib.c
index 646c43f921c..3a74a63dd4f 100644
--- a/drivers/video/sbuslib.c
+++ b/drivers/video/sbuslib.c
@@ -46,6 +46,9 @@ int sbusfb_mmap_helper(struct sbus_mmap_map *map,
 	unsigned long off;
 	int i;
                                         
+	if (!(vma->vm_flags & (VM_SHARED | VM_MAYSHARE)))
+		return -EINVAL;
+
 	size = vma->vm_end - vma->vm_start;
 	if (vma->vm_pgoff > (~0UL >> PAGE_SHIFT))
 		return -EINVAL;