[PATCH 6/7] pid: mark struct task const in helper functions

From: Richard Guy Briggs
Date: Thu Jan 23 2014 - 14:34:42 EST


It doesn't make any sense to recallers to pass in a non-const struct
task so update the function signatures to only require a const struct
task.

(informed by ebiederman's c76b2526)
Cc: "Eric W. Biederman" <ebiederm@xxxxxxxxxxxx>
Signed-off-by: Richard Guy Briggs <rgb@xxxxxxxxxx>
---
include/linux/sched.h | 36 ++++++++++++++++++------------------
kernel/pid.c | 4 ++--
2 files changed, 20 insertions(+), 20 deletions(-)

diff --git a/include/linux/sched.h b/include/linux/sched.h
index f60de19..2016d92 100644
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -1488,12 +1488,12 @@ static inline void task_numa_free(struct task_struct *p)
}
#endif

-static inline struct pid *task_pid(struct task_struct *task)
+static inline struct pid *task_pid(const struct task_struct *task)
{
return task->pids[PIDTYPE_PID].pid;
}

-static inline struct pid *task_tgid(struct task_struct *task)
+static inline struct pid *task_tgid(const struct task_struct *task)
{
return task->group_leader->pids[PIDTYPE_PID].pid;
}
@@ -1503,12 +1503,12 @@ static inline struct pid *task_tgid(struct task_struct *task)
* the result of task_pgrp/task_session even if task == current,
* we can race with another thread doing sys_setsid/sys_setpgid.
*/
-static inline struct pid *task_pgrp(struct task_struct *task)
+static inline struct pid *task_pgrp(const struct task_struct *task)
{
return task->group_leader->pids[PIDTYPE_PGID].pid;
}

-static inline struct pid *task_session(struct task_struct *task)
+static inline struct pid *task_session(const struct task_struct *task)
{
return task->group_leader->pids[PIDTYPE_SID].pid;
}
@@ -1528,64 +1528,64 @@ struct pid_namespace;
*
* see also pid_nr() etc in include/linux/pid.h
*/
-pid_t __task_pid_nr_ns(struct task_struct *task, enum pid_type type,
+pid_t __task_pid_nr_ns(const struct task_struct *task, enum pid_type type,
struct pid_namespace *ns);

-static inline pid_t task_pid_nr(struct task_struct *tsk)
+static inline pid_t task_pid_nr(const struct task_struct *tsk)
{
return tsk->pid;
}

-static inline pid_t task_pid_nr_ns(struct task_struct *tsk,
+static inline pid_t task_pid_nr_ns(const struct task_struct *tsk,
struct pid_namespace *ns)
{
return __task_pid_nr_ns(tsk, PIDTYPE_PID, ns);
}

-static inline pid_t task_pid_vnr(struct task_struct *tsk)
+static inline pid_t task_pid_vnr(const struct task_struct *tsk)
{
return __task_pid_nr_ns(tsk, PIDTYPE_PID, NULL);
}


-static inline pid_t task_tgid_nr(struct task_struct *tsk)
+static inline pid_t task_tgid_nr(const const struct task_struct *tsk)
{
return pid_nr(task_tgid(tsk));
}

-pid_t task_tgid_nr_ns(struct task_struct *tsk, struct pid_namespace *ns);
+pid_t task_tgid_nr_ns(const struct task_struct *tsk, struct pid_namespace *ns);

-static inline pid_t task_tgid_vnr(struct task_struct *tsk)
+static inline pid_t task_tgid_vnr(const struct task_struct *tsk)
{
return pid_vnr(task_tgid(tsk));
}


-static inline pid_t task_pgrp_nr_ns(struct task_struct *tsk,
+static inline pid_t task_pgrp_nr_ns(const struct task_struct *tsk,
struct pid_namespace *ns)
{
return __task_pid_nr_ns(tsk, PIDTYPE_PGID, ns);
}

-static inline pid_t task_pgrp_vnr(struct task_struct *tsk)
+static inline pid_t task_pgrp_vnr(const struct task_struct *tsk)
{
return __task_pid_nr_ns(tsk, PIDTYPE_PGID, NULL);
}


-static inline pid_t task_session_nr_ns(struct task_struct *tsk,
+static inline pid_t task_session_nr_ns(const struct task_struct *tsk,
struct pid_namespace *ns)
{
return __task_pid_nr_ns(tsk, PIDTYPE_SID, ns);
}

-static inline pid_t task_session_vnr(struct task_struct *tsk)
+static inline pid_t task_session_vnr(const struct task_struct *tsk)
{
return __task_pid_nr_ns(tsk, PIDTYPE_SID, NULL);
}

/* obsolete, do not use */
-static inline pid_t task_pgrp_nr(struct task_struct *tsk)
+static inline pid_t task_pgrp_nr(const struct task_struct *tsk)
{
return task_pgrp_nr_ns(tsk, &init_pid_ns);
}
@@ -1600,7 +1600,7 @@ static inline pid_t task_pgrp_nr(struct task_struct *tsk)
*
* Return: 1 if the process is alive. 0 otherwise.
*/
-static inline int pid_alive(struct task_struct *p)
+static inline int pid_alive(const struct task_struct *p)
{
return p->pids[PIDTYPE_PID].pid != NULL;
}
@@ -1613,7 +1613,7 @@ static inline int pid_alive(struct task_struct *p)
*
* Return: 1 if the task structure is init. 0 otherwise.
*/
-static inline int is_global_init(struct task_struct *tsk)
+static inline int is_global_init(const struct task_struct *tsk)
{
return task_pid_nr(tsk) == 1;
}
diff --git a/kernel/pid.c b/kernel/pid.c
index 9b9a266..468b35c 100644
--- a/kernel/pid.c
+++ b/kernel/pid.c
@@ -512,7 +512,7 @@ pid_t pid_vnr(struct pid *pid)
}
EXPORT_SYMBOL_GPL(pid_vnr);

-pid_t __task_pid_nr_ns(struct task_struct *task, enum pid_type type,
+pid_t __task_pid_nr_ns(const struct task_struct *task, enum pid_type type,
struct pid_namespace *ns)
{
pid_t nr = 0;
@@ -531,7 +531,7 @@ pid_t __task_pid_nr_ns(struct task_struct *task, enum pid_type type,
}
EXPORT_SYMBOL(__task_pid_nr_ns);

-pid_t task_tgid_nr_ns(struct task_struct *tsk, struct pid_namespace *ns)
+pid_t task_tgid_nr_ns(const struct task_struct *tsk, struct pid_namespace *ns)
{
return pid_nr_ns(task_tgid(tsk), ns);
}
--
1.7.1

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