/proc/kcore: fix stat.st_size
Presently the size of /proc/kcore which can be read by 'ls -l' is 0. But
it's not the correct value.
On x86-64, ls -l shows
... root root 140737486266368 2009-09-17 10:29 /proc/kcore
Then, 7FFFFFFE02000. This comes from vmalloc area's size.
(*) This shows "core" size, not memory size.
This patch shows the size by updating "size" field in struct
proc_dir_entry. Later, lookup routine will create inode and fill
inode->i_size based on this value. Then, this has a problem.
- Once inode is cached, inode->i_size will never be updated.
Then, this patch is not memory-hotplug-aware.
To update inode->i_size, we have to know dentry or inode.
But there is no way to lookup them by inside kernel. Hmmm....
Next patch will try it.
Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Acked-by: WANG Cong <xiyou.wangcong@gmail.com>
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 7073378..3d0485c 100644
--- a/fs/proc/kcore.c
+++ b/fs/proc/kcore.c
@@ -107,6 +107,8 @@
*/
static void __kcore_update_ram(struct list_head *list)
{
+ int nphdr;
+ size_t size;
struct kcore_list *tmp, *pos;
LIST_HEAD(garbage);
@@ -121,6 +123,7 @@
} else
list_splice(list, &garbage);
kcore_need_update = 0;
+ proc_root_kcore->size = get_kcore_size(&nphdr, &size);
write_unlock(&kclist_lock);
free_kclist_ents(&garbage);
@@ -429,7 +432,8 @@
unsigned long start;
read_lock(&kclist_lock);
- proc_root_kcore->size = size = get_kcore_size(&nphdr, &elf_buflen);
+ size = get_kcore_size(&nphdr, &elf_buflen);
+
if (buflen == 0 || *fpos >= size) {
read_unlock(&kclist_lock);
return 0;
