From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Eric W. Biederman" Subject: [PATCH 05/21] userns: Make seq_file's user namespace accessible Date: Mon, 13 Aug 2012 13:18:19 -0700 Message-ID: <1344889115-21610-5-git-send-email-ebiederm@xmission.com> References: <87ehnav9n5.fsf@xmission.com> <1344889115-21610-1-git-send-email-ebiederm@xmission.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: Eric Dumazet , containers-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Al Viro , Alexey Dobriyan , "Eric W. Biederman" , David Miller To: Return-path: In-Reply-To: <1344889115-21610-1-git-send-email-ebiederm-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: containers-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org Errors-To: containers-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org List-Id: netdev.vger.kernel.org From: "Eric W. Biederman" 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 Cc: Eric Dumazet Cc: KAMEZAWA Hiroyuki Cc: Alexey Dobriyan Acked-by: Serge Hallyn Signed-off-by: Eric W. Biederman --- fs/seq_file.c | 4 ++++ 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 14cf9de..99dffab 100644 --- a/fs/seq_file.c +++ b/fs/seq_file.c @@ -9,6 +9,7 @@ #include #include #include +#include #include #include @@ -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 83c44ee..68a04a3 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 -- 1.7.5.4