diff options
| author | Eric W. Biederman <ebiederm@xmission.com> | 2012-05-23 18:01:20 -0600 |
|---|---|---|
| committer | Eric W. Biederman <ebiederm@xmission.com> | 2012-08-14 21:47:55 -0700 |
| commit | adb37c4c67f807f16beb222028fb3ce9a354dc2b (patch) | |
| tree | 59f46f84b013f1a6390c72d58fe5b158c6e4b58e | |
| parent | fc5795c8a94c2d0b221dffae9ebb22686b3dafd8 (diff) | |
| download | lwn-adb37c4c67f807f16beb222028fb3ce9a354dc2b.tar.gz lwn-adb37c4c67f807f16beb222028fb3ce9a354dc2b.zip | |
userns: Make seq_file's user namespace accessible
struct file already has a user namespace associated with it
in file->f_cred->user_ns, unfortunately because struct
seq_file has no struct file backpointer associated with
it, it is difficult to get at the user namespace in seq_file
context. Therefore add a helper function seq_user_ns to return
the associated user namespace and a user_ns field to struct
seq_file to be used in implementing seq_user_ns.
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Alexey Dobriyan <adobriyan@gmail.com>
Acked-by: David S. Miller <davem@davemloft.net>
Acked-by: Serge Hallyn <serge.hallyn@canonical.com>
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
| -rw-r--r-- | fs/seq_file.c | 4 | ||||
| -rw-r--r-- | include/linux/seq_file.h | 14 |
2 files changed, 18 insertions, 0 deletions
diff --git a/fs/seq_file.c b/fs/seq_file.c index 14cf9de1dbe1..99dffab4c4e4 100644 --- a/fs/seq_file.c +++ b/fs/seq_file.c @@ -9,6 +9,7 @@ #include <linux/export.h> #include <linux/seq_file.h> #include <linux/slab.h> +#include <linux/cred.h> #include <asm/uaccess.h> #include <asm/page.h> @@ -56,6 +57,9 @@ int seq_open(struct file *file, const struct seq_operations *op) memset(p, 0, sizeof(*p)); mutex_init(&p->lock); p->op = op; +#ifdef CONFIG_USER_NS + p->user_ns = file->f_cred->user_ns; +#endif /* * Wrappers around seq_open(e.g. swaps_open) need to be diff --git a/include/linux/seq_file.h b/include/linux/seq_file.h index 83c44eefe698..68a04a343cad 100644 --- a/include/linux/seq_file.h +++ b/include/linux/seq_file.h @@ -13,6 +13,7 @@ struct file; struct path; struct inode; struct dentry; +struct user_namespace; struct seq_file { char *buf; @@ -25,6 +26,9 @@ struct seq_file { struct mutex lock; const struct seq_operations *op; int poll_event; +#ifdef CONFIG_USER_NS + struct user_namespace *user_ns; +#endif void *private; }; @@ -128,6 +132,16 @@ int seq_put_decimal_ull(struct seq_file *m, char delimiter, int seq_put_decimal_ll(struct seq_file *m, char delimiter, long long num); +static inline struct user_namespace *seq_user_ns(struct seq_file *seq) +{ +#ifdef CONFIG_USER_NS + return seq->user_ns; +#else + extern struct user_namespace init_user_ns; + return &init_user_ns; +#endif +} + #define SEQ_START_TOKEN ((void *)1) /* * Helpers for iteration over list_head-s in seq_files |