[PATCH] Check if start address is in vma region in NOMMU function get_user_pages()
In NOMMU arch, if run "cat /proc/self/mem", data from physical address 0
are read. This behavior is different from MMU arch. In IA32, message
"cat: /proc/self/mem: Input/output error" is reported.
This issue is rootcaused by not validate the start address in NOMMU
function get_user_pages(). Following patch solves this issue.
Signed-off-by: Sonic Zhang <sonic.adi@gmail.com>
Cc: David Howells <dhowells@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/mm/nommu.c b/mm/nommu.c
index 00ffa97..2af5083 100644
--- a/mm/nommu.c
+++ b/mm/nommu.c
@@ -129,16 +129,20 @@
struct page **pages, struct vm_area_struct **vmas)
{
int i;
- static struct vm_area_struct dummy_vma;
+ struct vm_area_struct *vma;
for (i = 0; i < len; i++) {
+ vma = find_vma(mm, start);
+ if(!vma)
+ return i ? : -EFAULT;
+
if (pages) {
pages[i] = virt_to_page(start);
if (pages[i])
page_cache_get(pages[i]);
}
if (vmas)
- vmas[i] = &dummy_vma;
+ vmas[i] = vma;
start += PAGE_SIZE;
}
return(i);
