[PATCH] add process_session() helper routine: deprecate old field

Add an anonymous union and ((deprecated)) to catch direct usage of the
session field.

[akpm@osdl.org: fix various missed conversions]
[jdike@addtoit.com: fix UML bug]
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Cc: Cedric Le Goater <clg@fr.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

6 files changed, 27 insertions, 11 deletions

diff --git a/drivers/char/tty_io.c b/drivers/char/tty_io.c
index 4ebba7ca1dc9..48cee2004e97 100644
--- a/drivers/char/tty_io.c
+++ b/drivers/char/tty_io.c
@@ -3855,7 +3855,7 @@ EXPORT_SYMBOL(proc_clear_tty);
 void __proc_set_tty(struct task_struct *tsk, struct tty_struct *tty)
 {
         if (tty) {
-                tty->session = tsk->signal->session;
+                tty->session = process_session(tsk);
                 tty->pgrp = process_group(tsk);
         }
         tsk->signal->tty = tty;
diff --git a/fs/proc/array.c b/fs/proc/array.c
index b0cd014a39bd..70e4fab117b1 100644
--- a/fs/proc/array.c
+++ b/fs/proc/array.c
@@ -381,7 +381,7 @@ static int do_task_stat(struct task_struct *task, char * buffer, int whole)
                         stime = cputime_add(stime, sig->stime);
                 }
 
-                sid = sig->session;
+                sid = signal_session(sig);
                 pgid = process_group(task);
                 ppid = rcu_dereference(task->real_parent)->tgid;
 
diff --git a/include/linux/init_task.h b/include/linux/init_task.h
index 733790d4f7db..848a68af3d42 100644
--- a/include/linux/init_task.h
+++ b/include/linux/init_task.h
@@ -57,17 +57,18 @@
         .cpu_vm_mask    = CPU_MASK_ALL,                         \
 }
 
-#define INIT_SIGNALS(sig) {     \
-        .count          = ATOMIC_INIT(1),               \
+#define INIT_SIGNALS(sig) {                                             \
+        .count          = ATOMIC_INIT(1),                               \
         .wait_chldexit  = __WAIT_QUEUE_HEAD_INITIALIZER(sig.wait_chldexit),\
-        .shared_pending = {                             \
+        .shared_pending = {                                             \
                 .list = LIST_HEAD_INIT(sig.shared_pending.list),        \
-                .signal =  {{0}}}, \
+                .signal =  {{0}}},                                      \
         .posix_timers    = LIST_HEAD_INIT(sig.posix_timers),            \
         .cpu_timers     = INIT_CPU_TIMERS(sig.cpu_timers),              \
         .rlim           = INIT_RLIMITS,                                 \
         .pgrp           = 1,                                            \
-        .session        = 1,                                            \
+        .tty_old_pgrp   = 0,                                            \
+        { .__session      = 1},                                         \
 }
 
 extern struct nsproxy init_nsproxy;
diff --git a/include/linux/sched.h b/include/linux/sched.h
index 270d864a8ff1..6fec1d419714 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -436,7 +436,12 @@ struct signal_struct {
         /* job control IDs */
         pid_t pgrp;
         pid_t tty_old_pgrp;
-        pid_t session;
+
+        union {
+                pid_t session __deprecated;
+                pid_t __session;
+        };
+
         /* boolean value for session group leader */
         int leader;
 
@@ -1047,9 +1052,19 @@ static inline pid_t process_group(struct task_struct *tsk)
         return tsk->signal->pgrp;
 }
 
+static inline pid_t signal_session(struct signal_struct *sig)
+{
+        return sig->__session;
+}
+
 static inline pid_t process_session(struct task_struct *tsk)
 {
-        return tsk->signal->session;
+        return signal_session(tsk->signal);
+}
+
+static inline void set_signal_session(struct signal_struct *sig, pid_t session)
+{
+        sig->__session = session;
 }
 
 static inline struct pid *task_pid(struct task_struct *task)
diff --git a/kernel/exit.c b/kernel/exit.c
index 8d289bfc13d1..6267a6cc6113 100644
--- a/kernel/exit.c
+++ b/kernel/exit.c
@@ -304,7 +304,7 @@ void __set_special_pids(pid_t session, pid_t pgrp)
 
         if (process_session(curr) != session) {
                 detach_pid(curr, PIDTYPE_SID);
-                curr->signal->session = session;
+                set_signal_session(curr->signal, session);
                 attach_pid(curr, PIDTYPE_SID, session);
         }
         if (process_group(curr) != pgrp) {
diff --git a/kernel/fork.c b/kernel/fork.c
index 298c4d6ab512..60d2644bfe85 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -1259,7 +1259,7 @@ static struct task_struct *copy_process(unsigned long clone_flags,
                 if (thread_group_leader(p)) {
                         p->signal->tty = current->signal->tty;
                         p->signal->pgrp = process_group(current);
-                        p->signal->session = process_session(current);
+                        set_signal_session(p->signal, process_session(current));
                         attach_pid(p, PIDTYPE_PGID, process_group(p));
                         attach_pid(p, PIDTYPE_SID, process_session(p));