proc: seqfile convert proc_pid_status to properly handle pid namespaces

Currently we possibly lookup the pid in the wrong pid namespace.  So
seq_file convert proc_pid_status which ensures the proper pid namespaces is
passed in.

[akpm@linux-foundation.org: coding-style fixes]
[akpm@linux-foundation.org: build fix]
[akpm@linux-foundation.org: another build fix]
[akpm@linux-foundation.org: s390 build fix]
[akpm@linux-foundation.org: fix task_name() output]
[akpm@linux-foundation.org: fix nommu build]
Signed-off-by: Eric W. Biederman <ebiederm@xmission.com>
Cc: Andrew Morgan <morgan@kernel.org>
Cc: Serge Hallyn <serue@us.ibm.com>
Cc: Cedric Le Goater <clg@fr.ibm.com>
Cc: Pavel Emelyanov <xemul@openvz.org>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Paul Menage <menage@google.com>
Cc: Paul Jackson <pj@sgi.com>
Cc: David Rientjes <rientjes@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 10 insertions, 9 deletions

diff --git a/kernel/cpuset.c b/kernel/cpuset.c
index 67b2bfe27814..3e296ed81d4d 100644
--- a/kernel/cpuset.c
+++ b/kernel/cpuset.c
@@ -2255,13 +2255,14 @@ const struct file_operations proc_cpuset_operations = {
 #endif /* CONFIG_PROC_PID_CPUSET */
 
 /* Display task cpus_allowed, mems_allowed in /proc/<pid>/status file. */
-char *cpuset_task_status_allowed(struct task_struct *task, char *buffer)
-{
-        buffer += sprintf(buffer, "Cpus_allowed:\t");
-        buffer += cpumask_scnprintf(buffer, PAGE_SIZE, task->cpus_allowed);
-        buffer += sprintf(buffer, "\n");
-        buffer += sprintf(buffer, "Mems_allowed:\t");
-        buffer += nodemask_scnprintf(buffer, PAGE_SIZE, task->mems_allowed);
-        buffer += sprintf(buffer, "\n");
-        return buffer;
+void cpuset_task_status_allowed(struct seq_file *m, struct task_struct *task)
+{
+        seq_printf(m, "Cpus_allowed:\t");
+        m->count += cpumask_scnprintf(m->buf + m->count, m->size - m->count,
+                                        task->cpus_allowed);
+        seq_printf(m, "\n");
+        seq_printf(m, "Mems_allowed:\t");
+        m->count += nodemask_scnprintf(m->buf + m->count, m->size - m->count,
+                                        task->mems_allowed);
+        seq_printf(m, "\n");
 }