There are several functions that do find_task_by_vpid() followed by get_task_struct(). We can use a helper function instead.
Signed-off-by: Mike Rapoport <[email protected]> --- include/linux/sched.h | 5 +++++ kernel/futex.c | 7 +------ kernel/pid.c | 13 +++++++++++++ kernel/ptrace.c | 6 +----- kernel/taskstats.c | 6 +----- mm/process_vm_access.c | 6 +----- 6 files changed, 22 insertions(+), 21 deletions(-) diff --git a/include/linux/sched.h b/include/linux/sched.h index 26a7df4e558c..4c3af5255fcf 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1484,6 +1484,11 @@ static inline struct thread_info *task_thread_info(struct task_struct *task) extern struct task_struct *find_task_by_vpid(pid_t nr); extern struct task_struct *find_task_by_pid_ns(pid_t nr, struct pid_namespace *ns); +/* + * find a task by its virtual pid and get the task struct + */ +extern struct task_struct *find_get_task_by_vpid(pid_t nr); + extern int wake_up_state(struct task_struct *tsk, unsigned int state); extern int wake_up_process(struct task_struct *tsk); extern void wake_up_new_task(struct task_struct *tsk); diff --git a/kernel/futex.c b/kernel/futex.c index 0518a0bfc746..6446aa9f2288 100644 --- a/kernel/futex.c +++ b/kernel/futex.c @@ -870,12 +870,7 @@ static struct task_struct *futex_find_get_task(pid_t pid) { struct task_struct *p; - rcu_read_lock(); - p = find_task_by_vpid(pid); - if (p) - get_task_struct(p); - - rcu_read_unlock(); + p = find_get_task_by_vpid(pid); return p; } diff --git a/kernel/pid.c b/kernel/pid.c index 020dedbdf066..ead086b0ef8e 100644 --- a/kernel/pid.c +++ b/kernel/pid.c @@ -462,6 +462,19 @@ struct task_struct *find_task_by_vpid(pid_t vnr) return find_task_by_pid_ns(vnr, task_active_pid_ns(current)); } +struct task_struct *find_get_task_by_vpid(pid_t nr) +{ + struct task_struct *task; + + rcu_read_lock(); + task = find_task_by_vpid(nr); + if (task) + get_task_struct(task); + rcu_read_unlock(); + + return task; +} + struct pid *get_task_pid(struct task_struct *task, enum pid_type type) { struct pid *pid; diff --git a/kernel/ptrace.c b/kernel/ptrace.c index 84b1367935e4..91efc97674ce 100644 --- a/kernel/ptrace.c +++ b/kernel/ptrace.c @@ -1103,11 +1103,7 @@ static struct task_struct *ptrace_get_task_struct(pid_t pid) { struct task_struct *child; - rcu_read_lock(); - child = find_task_by_vpid(pid); - if (child) - get_task_struct(child); - rcu_read_unlock(); + child = find_get_task_by_vpid(pid); if (!child) return ERR_PTR(-ESRCH); diff --git a/kernel/taskstats.c b/kernel/taskstats.c index 4559e914452b..4e62a4a8fa91 100644 --- a/kernel/taskstats.c +++ b/kernel/taskstats.c @@ -194,11 +194,7 @@ static int fill_stats_for_pid(pid_t pid, struct taskstats *stats) { struct task_struct *tsk; - rcu_read_lock(); - tsk = find_task_by_vpid(pid); - if (tsk) - get_task_struct(tsk); - rcu_read_unlock(); + tsk = find_get_task_by_vpid(pid); if (!tsk) return -ESRCH; fill_stats(current_user_ns(), task_active_pid_ns(current), tsk, stats); diff --git a/mm/process_vm_access.c b/mm/process_vm_access.c index 8973cd231ece..16424b9ae424 100644 --- a/mm/process_vm_access.c +++ b/mm/process_vm_access.c @@ -197,11 +197,7 @@ static ssize_t process_vm_rw_core(pid_t pid, struct iov_iter *iter, } /* Get process information */ - rcu_read_lock(); - task = find_task_by_vpid(pid); - if (task) - get_task_struct(task); - rcu_read_unlock(); + task = find_get_task_by_vpid(pid); if (!task) { rc = -ESRCH; goto free_proc_pages; -- 2.7.4
