get_user_pages: don't try to follow PFNMAP pages
Nick Piggin points out that a few drivers play games with VM_IO (why?
who knows..) and thus a pfn-remapped area may not have that bit set even
if remap_pfn_range() set it originally.
So make it explicit in get_user_pages() that we don't follow VM_PFNMAP
pages, since pretty much by definition they do not have a "struct page"
associated with them.
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/mm/memory.c b/mm/memory.c
index 47c533e..d22f78c 100644
--- a/mm/memory.c
+++ b/mm/memory.c
@@ -1009,7 +1009,7 @@
continue;
}
- if (!vma || (vma->vm_flags & VM_IO)
+ if (!vma || (vma->vm_flags & (VM_IO | VM_PFNMAP))
|| !(vm_flags & vma->vm_flags))
return i ? : -EFAULT;