kcore: /proc/kcore should use vread
/proc/kcore has its own routine to access vmallc area. It can be replaced
with vread(). And by this, /proc/kcore can do safe access to vmalloc
area.
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: WANG Cong <xiyou.wangcong@gmail.com>
Cc: Mike Smith <scgtrp@gmail.com>
Cc: Nick Piggin <nickpiggin@yahoo.com.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/fs/proc/kcore.c b/fs/proc/kcore.c
index 59b43a0..f06f45b4 100644
--- a/fs/proc/kcore.c
+++ b/fs/proc/kcore.c
@@ -328,43 +328,12 @@
return -EFAULT;
} else if (is_vmalloc_addr((void *)start)) {
char * elf_buf;
- struct vm_struct *m;
- unsigned long curstart = start;
- unsigned long cursize = tsz;
elf_buf = kzalloc(tsz, GFP_KERNEL);
if (!elf_buf)
return -ENOMEM;
-
- read_lock(&vmlist_lock);
- for (m=vmlist; m && cursize; m=m->next) {
- unsigned long vmstart;
- unsigned long vmsize;
- unsigned long msize = m->size - PAGE_SIZE;
-
- if (((unsigned long)m->addr + msize) <
- curstart)
- continue;
- if ((unsigned long)m->addr > (curstart +
- cursize))
- break;
- vmstart = (curstart < (unsigned long)m->addr ?
- (unsigned long)m->addr : curstart);
- if (((unsigned long)m->addr + msize) >
- (curstart + cursize))
- vmsize = curstart + cursize - vmstart;
- else
- vmsize = (unsigned long)m->addr +
- msize - vmstart;
- curstart = vmstart + vmsize;
- cursize -= vmsize;
- /* don't dump ioremap'd stuff! (TA) */
- if (m->flags & VM_IOREMAP)
- continue;
- memcpy(elf_buf + (vmstart - start),
- (char *)vmstart, vmsize);
- }
- read_unlock(&vmlist_lock);
+ vread(elf_buf, (char *)start, tsz);
+ /* we have to zero-fill user buffer even if no read */
if (copy_to_user(buffer, elf_buf, tsz)) {
kfree(elf_buf);
return -EFAULT;