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>
This commit is contained in:
KAMEZAWA Hiroyuki 2009-09-21 17:02:35 -07:00 committed by Linus Torvalds
parent d0107eb073
commit 73d7c33e81

View file

@ -328,43 +328,12 @@ read_kcore(struct file *file, char __user *buffer, size_t buflen, loff_t *fpos)
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;