From 678ad5d8aaf8925cb8465f84e1e47d9b1284666a Mon Sep 17 00:00:00 2001 From: KAMEZAWA Hiroyuki Date: Tue, 22 Sep 2009 16:45:51 -0700 Subject: [PATCH] /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 Acked-by: WANG Cong Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/proc/kcore.c | 6 +++++- 1 file changed, 5 insertions(+), 1 deletion(-) diff --git a/fs/proc/kcore.c b/fs/proc/kcore.c index 70733780fdd..3d0485c361c 100644 --- a/fs/proc/kcore.c +++ b/fs/proc/kcore.c @@ -107,6 +107,8 @@ static void free_kclist_ents(struct list_head *head) */ 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 @@ static void __kcore_update_ram(struct list_head *list) } 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 @@ read_kcore(struct file *file, char __user *buffer, size_t buflen, loff_t *fpos) 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;