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authorPavel Emelyanov <xemul@openvz.org>2008-03-07 14:08:40 -0500
committerDavid S. Miller <davem@davemloft.net>2008-03-07 14:08:40 -0500
commite9720acd728a46cb40daa52c99a979f7c4ff195c (patch)
tree01380f601384cf93f30dedb64afe80359fecb807 /include/linux/proc_fs.h
parent1ff82fe0024e8070c38346b8abc1ff09612dea4c (diff)
[NET]: Make /proc/net a symlink on /proc/self/net (v3)
Current /proc/net is done with so called "shadows", but current implementation is broken and has little chances to get fixed. The problem is that dentries subtree of /proc/net directory has fancy revalidation rules to make processes living in different net namespaces see different entries in /proc/net subtree, but currently, tasks see in the /proc/net subdir the contents of any other namespace, depending on who opened the file first. The proposed fix is to turn /proc/net into a symlink, which points to /proc/self/net, which in turn shows what previously was in /proc/net - the network-related info, from the net namespace the appropriate task lives in. # ls -l /proc/net lrwxrwxrwx 1 root root 8 Mar 5 15:17 /proc/net -> self/net In other words - this behaves like /proc/mounts, but unlike "mounts", "net" is not a file, but a directory. Changes from v2: * Fixed discrepancy of /proc/net nlink count and selinux labeling screwup pointed out by Stephen. To get the correct nlink count the ->getattr callback for /proc/net is overridden to read one from the net->proc_net entry. To make selinux still work the net->proc_net entry is initialized properly, i.e. with the "net" name and the proc_net parent. Selinux fixes are Acked-by: Stephen Smalley <sds@tycho.nsa.gov> Changes from v1: * Fixed a task_struct leak in get_proc_task_net, pointed out by Paul. Signed-off-by: Pavel Emelyanov <xemul@openvz.org> Acked-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include/linux/proc_fs.h')
-rw-r--r--include/linux/proc_fs.h3
1 files changed, 0 insertions, 3 deletions
diff --git a/include/linux/proc_fs.h b/include/linux/proc_fs.h
index d9a9e718ad19..9b6c935f69cf 100644
--- a/include/linux/proc_fs.h
+++ b/include/linux/proc_fs.h
@@ -50,8 +50,6 @@ typedef int (read_proc_t)(char *page, char **start, off_t off,
50typedef int (write_proc_t)(struct file *file, const char __user *buffer, 50typedef int (write_proc_t)(struct file *file, const char __user *buffer,
51 unsigned long count, void *data); 51 unsigned long count, void *data);
52typedef int (get_info_t)(char *, char **, off_t, int); 52typedef int (get_info_t)(char *, char **, off_t, int);
53typedef struct proc_dir_entry *(shadow_proc_t)(struct task_struct *task,
54 struct proc_dir_entry *pde);
55 53
56struct proc_dir_entry { 54struct proc_dir_entry {
57 unsigned int low_ino; 55 unsigned int low_ino;
@@ -82,7 +80,6 @@ struct proc_dir_entry {
82 int pde_users; /* number of callers into module in progress */ 80 int pde_users; /* number of callers into module in progress */
83 spinlock_t pde_unload_lock; /* proc_fops checks and pde_users bumps */ 81 spinlock_t pde_unload_lock; /* proc_fops checks and pde_users bumps */
84 struct completion *pde_unload_completion; 82 struct completion *pde_unload_completion;
85 shadow_proc_t *shadow_proc;
86}; 83};
87 84
88struct kcore_list { 85struct kcore_list {