From 8053bdd5ce15dcf043d41a4dd6cac4a5567effdc Mon Sep 17 00:00:00 2001 From: Oleg Nesterov Date: Wed, 17 Jun 2009 16:27:34 -0700 Subject: ptrace_get_task_struct: s/tasklist/rcu/, make it static - Use rcu_read_lock() instead of tasklist_lock to find/get the task in ptrace_get_task_struct(). - Make it static, it has no callers outside of ptrace.c. - The comment doesn't match the reality, this helper does not do any checks. Beacuse it is really trivial and static I removed the whole comment. Signed-off-by: Oleg Nesterov Acked-by: Roland McGrath Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- kernel/ptrace.c | 16 +++------------- 1 file changed, 3 insertions(+), 13 deletions(-) (limited to 'kernel/ptrace.c') diff --git a/kernel/ptrace.c b/kernel/ptrace.c index 38fdfea1a15..a64fe75a48b 100644 --- a/kernel/ptrace.c +++ b/kernel/ptrace.c @@ -581,26 +581,16 @@ int ptrace_request(struct task_struct *child, long request, return ret; } -/** - * ptrace_get_task_struct -- grab a task struct reference for ptrace - * @pid: process id to grab a task_struct reference of - * - * This function is a helper for ptrace implementations. It checks - * permissions and then grabs a task struct for use of the actual - * ptrace implementation. - * - * Returns the task_struct for @pid or an ERR_PTR() on failure. - */ -struct task_struct *ptrace_get_task_struct(pid_t pid) +static struct task_struct *ptrace_get_task_struct(pid_t pid) { struct task_struct *child; - read_lock(&tasklist_lock); + rcu_read_lock(); child = find_task_by_vpid(pid); if (child) get_task_struct(child); + rcu_read_unlock(); - read_unlock(&tasklist_lock); if (!child) return ERR_PTR(-ESRCH); return child; -- cgit v1.2.3