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ftrace: Have set_ftrace_pid use the bitmap like events do
Convert set_ftrace_pid to use the bitmap like set_event_pid does. This allows for instances to use the pid filtering as well, and will allow for function-fork option to set if the children of a traced function should be traced or not. Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
This commit is contained in:
Steven Rostedt (Red Hat)
Steven Rostedt
parent
76c813e266
commit
345ddcc882
5 changed files with 158 additions and 195 deletions
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@ -89,16 +89,16 @@ struct ftrace_ops *function_trace_op __read_mostly = &ftrace_list_end;
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/* What to set function_trace_op to */
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static struct ftrace_ops *set_function_trace_op;
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/* List for set_ftrace_pid's pids. */
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LIST_HEAD(ftrace_pids);
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struct ftrace_pid {
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struct list_head list;
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struct pid *pid;
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};
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static bool ftrace_pids_enabled(void)
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static bool ftrace_pids_enabled(struct ftrace_ops *ops)
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{
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return !list_empty(&ftrace_pids);
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struct trace_array *tr;
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if (!(ops->flags & FTRACE_OPS_FL_PID) || !ops->private)
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return false;
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tr = ops->private;
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return tr->function_pids != NULL;
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}
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static void ftrace_update_trampoline(struct ftrace_ops *ops);
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@ -179,7 +179,9 @@ int ftrace_nr_registered_ops(void)
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static void ftrace_pid_func(unsigned long ip, unsigned long parent_ip,
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struct ftrace_ops *op, struct pt_regs *regs)
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{
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if (!test_tsk_trace_trace(current))
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struct trace_array *tr = op->private;
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if (tr && this_cpu_read(tr->trace_buffer.data->ftrace_ignore_pid))
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return;
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op->saved_func(ip, parent_ip, op, regs);
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@ -417,7 +419,7 @@ static int __register_ftrace_function(struct ftrace_ops *ops)
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/* Always save the function, and reset at unregistering */
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ops->saved_func = ops->func;
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if (ops->flags & FTRACE_OPS_FL_PID && ftrace_pids_enabled())
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if (ftrace_pids_enabled(ops))
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ops->func = ftrace_pid_func;
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ftrace_update_trampoline(ops);
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@ -450,7 +452,6 @@ static int __unregister_ftrace_function(struct ftrace_ops *ops)
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static void ftrace_update_pid_func(void)
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{
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bool enabled = ftrace_pids_enabled();
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struct ftrace_ops *op;
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/* Only do something if we are tracing something */
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@ -459,8 +460,8 @@ static void ftrace_update_pid_func(void)
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do_for_each_ftrace_op(op, ftrace_ops_list) {
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if (op->flags & FTRACE_OPS_FL_PID) {
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op->func = enabled ? ftrace_pid_func :
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op->saved_func;
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op->func = ftrace_pids_enabled(op) ?
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ftrace_pid_func : op->saved_func;
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ftrace_update_trampoline(op);
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}
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} while_for_each_ftrace_op(op);
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@ -5324,134 +5325,46 @@ ftrace_func_t ftrace_ops_get_func(struct ftrace_ops *ops)
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return ops->func;
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}
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static void clear_ftrace_swapper(void)
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static void
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ftrace_filter_pid_sched_switch_probe(void *data, bool preempt,
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struct task_struct *prev, struct task_struct *next)
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{
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struct task_struct *p;
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struct trace_array *tr = data;
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struct trace_pid_list *pid_list;
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pid_list = rcu_dereference_sched(tr->function_pids);
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this_cpu_write(tr->trace_buffer.data->ftrace_ignore_pid,
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trace_ignore_this_task(pid_list, next));
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}
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static void clear_ftrace_pids(struct trace_array *tr)
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{
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struct trace_pid_list *pid_list;
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int cpu;
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get_online_cpus();
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for_each_online_cpu(cpu) {
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p = idle_task(cpu);
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clear_tsk_trace_trace(p);
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}
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put_online_cpus();
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pid_list = rcu_dereference_protected(tr->function_pids,
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lockdep_is_held(&ftrace_lock));
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if (!pid_list)
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return;
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unregister_trace_sched_switch(ftrace_filter_pid_sched_switch_probe, tr);
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for_each_possible_cpu(cpu)
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per_cpu_ptr(tr->trace_buffer.data, cpu)->ftrace_ignore_pid = false;
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rcu_assign_pointer(tr->function_pids, NULL);
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/* Wait till all users are no longer using pid filtering */
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synchronize_sched();
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trace_free_pid_list(pid_list);
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}
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static void set_ftrace_swapper(void)
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static void ftrace_pid_reset(struct trace_array *tr)
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{
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struct task_struct *p;
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int cpu;
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get_online_cpus();
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for_each_online_cpu(cpu) {
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p = idle_task(cpu);
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set_tsk_trace_trace(p);
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}
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put_online_cpus();
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}
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static void clear_ftrace_pid(struct pid *pid)
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{
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struct task_struct *p;
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rcu_read_lock();
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do_each_pid_task(pid, PIDTYPE_PID, p) {
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clear_tsk_trace_trace(p);
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} while_each_pid_task(pid, PIDTYPE_PID, p);
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rcu_read_unlock();
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put_pid(pid);
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}
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static void set_ftrace_pid(struct pid *pid)
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{
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struct task_struct *p;
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rcu_read_lock();
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do_each_pid_task(pid, PIDTYPE_PID, p) {
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set_tsk_trace_trace(p);
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} while_each_pid_task(pid, PIDTYPE_PID, p);
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rcu_read_unlock();
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}
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static void clear_ftrace_pid_task(struct pid *pid)
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{
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if (pid == ftrace_swapper_pid)
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clear_ftrace_swapper();
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else
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clear_ftrace_pid(pid);
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}
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static void set_ftrace_pid_task(struct pid *pid)
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{
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if (pid == ftrace_swapper_pid)
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set_ftrace_swapper();
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else
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set_ftrace_pid(pid);
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}
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static int ftrace_pid_add(int p)
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{
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struct pid *pid;
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struct ftrace_pid *fpid;
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int ret = -EINVAL;
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mutex_lock(&ftrace_lock);
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if (!p)
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pid = ftrace_swapper_pid;
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else
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pid = find_get_pid(p);
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if (!pid)
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goto out;
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ret = 0;
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list_for_each_entry(fpid, &ftrace_pids, list)
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if (fpid->pid == pid)
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goto out_put;
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ret = -ENOMEM;
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fpid = kmalloc(sizeof(*fpid), GFP_KERNEL);
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if (!fpid)
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goto out_put;
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list_add(&fpid->list, &ftrace_pids);
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fpid->pid = pid;
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set_ftrace_pid_task(pid);
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ftrace_update_pid_func();
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ftrace_startup_all(0);
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mutex_unlock(&ftrace_lock);
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return 0;
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out_put:
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if (pid != ftrace_swapper_pid)
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put_pid(pid);
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out:
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mutex_unlock(&ftrace_lock);
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return ret;
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}
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static void ftrace_pid_reset(void)
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{
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struct ftrace_pid *fpid, *safe;
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mutex_lock(&ftrace_lock);
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list_for_each_entry_safe(fpid, safe, &ftrace_pids, list) {
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struct pid *pid = fpid->pid;
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clear_ftrace_pid_task(pid);
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list_del(&fpid->list);
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kfree(fpid);
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}
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clear_ftrace_pids(tr);
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ftrace_update_pid_func();
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ftrace_startup_all(0);
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@ -5459,44 +5372,52 @@ static void ftrace_pid_reset(void)
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mutex_unlock(&ftrace_lock);
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}
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/* Greater than any max PID */
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#define FTRACE_NO_PIDS (void *)(PID_MAX_LIMIT + 1)
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static void *fpid_start(struct seq_file *m, loff_t *pos)
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__acquires(RCU)
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{
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struct trace_pid_list *pid_list;
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struct trace_array *tr = m->private;
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mutex_lock(&ftrace_lock);
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rcu_read_lock_sched();
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if (!ftrace_pids_enabled() && (!*pos))
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return (void *) 1;
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pid_list = rcu_dereference_sched(tr->function_pids);
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return seq_list_start(&ftrace_pids, *pos);
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if (!pid_list)
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return !(*pos) ? FTRACE_NO_PIDS : NULL;
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return trace_pid_start(pid_list, pos);
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}
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static void *fpid_next(struct seq_file *m, void *v, loff_t *pos)
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{
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if (v == (void *)1)
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struct trace_array *tr = m->private;
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struct trace_pid_list *pid_list = rcu_dereference_sched(tr->function_pids);
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if (v == FTRACE_NO_PIDS)
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return NULL;
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return seq_list_next(v, &ftrace_pids, pos);
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return trace_pid_next(pid_list, v, pos);
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}
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static void fpid_stop(struct seq_file *m, void *p)
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__releases(RCU)
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{
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rcu_read_unlock_sched();
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mutex_unlock(&ftrace_lock);
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}
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static int fpid_show(struct seq_file *m, void *v)
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{
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const struct ftrace_pid *fpid = list_entry(v, struct ftrace_pid, list);
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if (v == (void *)1) {
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if (v == FTRACE_NO_PIDS) {
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seq_puts(m, "no pid\n");
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return 0;
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}
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if (fpid->pid == ftrace_swapper_pid)
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seq_puts(m, "swapper tasks\n");
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else
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seq_printf(m, "%u\n", pid_vnr(fpid->pid));
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return 0;
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return trace_pid_show(m, v);
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}
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static const struct seq_operations ftrace_pid_sops = {
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@ -5509,58 +5430,103 @@ static const struct seq_operations ftrace_pid_sops = {
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static int
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ftrace_pid_open(struct inode *inode, struct file *file)
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{
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struct trace_array *tr = inode->i_private;
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struct seq_file *m;
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int ret = 0;
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if (trace_array_get(tr) < 0)
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return -ENODEV;
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if ((file->f_mode & FMODE_WRITE) &&
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(file->f_flags & O_TRUNC))
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ftrace_pid_reset();
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ftrace_pid_reset(tr);
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if (file->f_mode & FMODE_READ)
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ret = seq_open(file, &ftrace_pid_sops);
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if (ret < 0) {
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trace_array_put(tr);
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} else {
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m = file->private_data;
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/* copy tr over to seq ops */
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m->private = tr;
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}
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return ret;
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}
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static void ignore_task_cpu(void *data)
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{
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struct trace_array *tr = data;
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struct trace_pid_list *pid_list;
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/*
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* This function is called by on_each_cpu() while the
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* event_mutex is held.
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*/
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pid_list = rcu_dereference_protected(tr->function_pids,
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mutex_is_locked(&ftrace_lock));
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this_cpu_write(tr->trace_buffer.data->ftrace_ignore_pid,
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trace_ignore_this_task(pid_list, current));
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}
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static ssize_t
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ftrace_pid_write(struct file *filp, const char __user *ubuf,
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size_t cnt, loff_t *ppos)
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{
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char buf[64], *tmp;
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long val;
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int ret;
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struct seq_file *m = filp->private_data;
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struct trace_array *tr = m->private;
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struct trace_pid_list *filtered_pids = NULL;
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struct trace_pid_list *pid_list;
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ssize_t ret;
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if (cnt >= sizeof(buf))
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return -EINVAL;
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if (!cnt)
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return 0;
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if (copy_from_user(&buf, ubuf, cnt))
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return -EFAULT;
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mutex_lock(&ftrace_lock);
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buf[cnt] = 0;
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filtered_pids = rcu_dereference_protected(tr->function_pids,
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lockdep_is_held(&ftrace_lock));
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ret = trace_pid_write(filtered_pids, &pid_list, ubuf, cnt);
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if (ret < 0)
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goto out;
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rcu_assign_pointer(tr->function_pids, pid_list);
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if (filtered_pids) {
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synchronize_sched();
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trace_free_pid_list(filtered_pids);
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} else if (pid_list) {
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/* Register a probe to set whether to ignore the tracing of a task */
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register_trace_sched_switch(ftrace_filter_pid_sched_switch_probe, tr);
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}
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/*
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* Allow "echo > set_ftrace_pid" or "echo -n '' > set_ftrace_pid"
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* to clean the filter quietly.
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* Ignoring of pids is done at task switch. But we have to
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* check for those tasks that are currently running.
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* Always do this in case a pid was appended or removed.
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*/
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tmp = strstrip(buf);
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if (strlen(tmp) == 0)
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return 1;
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on_each_cpu(ignore_task_cpu, tr, 1);
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ftrace_update_pid_func();
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ftrace_startup_all(0);
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out:
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mutex_unlock(&ftrace_lock);
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if (ret > 0)
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*ppos += ret;
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ret = kstrtol(tmp, 10, &val);
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if (ret < 0)
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return ret;
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ret = ftrace_pid_add(val);
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return ret ? ret : cnt;
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}
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static int
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ftrace_pid_release(struct inode *inode, struct file *file)
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{
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if (file->f_mode & FMODE_READ)
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seq_release(inode, file);
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struct trace_array *tr = inode->i_private;
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return 0;
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trace_array_put(tr);
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return seq_release(inode, file);
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}
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static const struct file_operations ftrace_pid_fops = {
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@ -5571,24 +5537,17 @@ static const struct file_operations ftrace_pid_fops = {
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.release = ftrace_pid_release,
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};
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static __init int ftrace_init_tracefs(void)
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void ftrace_init_tracefs(struct trace_array *tr, struct dentry *d_tracer)
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{
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struct dentry *d_tracer;
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d_tracer = tracing_init_dentry();
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if (IS_ERR(d_tracer))
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return 0;
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/* Only the top level directory has the dyn_tracefs and profile */
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if (tr->flags & TRACE_ARRAY_FL_GLOBAL) {
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ftrace_init_dyn_tracefs(d_tracer);
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ftrace_profile_tracefs(d_tracer);
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}
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trace_create_file("set_ftrace_pid", 0644, d_tracer,
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NULL, &ftrace_pid_fops);
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ftrace_profile_tracefs(d_tracer);
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return 0;
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tr, &ftrace_pid_fops);
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}
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fs_initcall(ftrace_init_tracefs);
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/**
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* ftrace_kill - kill ftrace
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@ -7233,6 +7233,7 @@ init_tracer_tracefs(struct trace_array *tr, struct dentry *d_tracer)
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for_each_tracing_cpu(cpu)
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tracing_init_tracefs_percpu(tr, cpu);
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ftrace_init_tracefs(tr, d_tracer);
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}
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static struct vfsmount *trace_automount(void *ingore)
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@ -156,6 +156,9 @@ struct trace_array_cpu {
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char comm[TASK_COMM_LEN];
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bool ignore_pid;
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#ifdef CONFIG_FUNCTION_TRACER
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bool ftrace_ignore_pid;
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#endif
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};
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struct tracer;
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@ -247,6 +250,7 @@ struct trace_array {
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int ref;
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#ifdef CONFIG_FUNCTION_TRACER
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struct ftrace_ops *ops;
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struct trace_pid_list __rcu *function_pids;
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/* function tracing enabled */
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int function_enabled;
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#endif
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@ -840,12 +844,9 @@ extern struct list_head ftrace_pids;
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|||
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||||
#ifdef CONFIG_FUNCTION_TRACER
|
||||
extern bool ftrace_filter_param __initdata;
|
||||
static inline int ftrace_trace_task(struct task_struct *task)
|
||||
static inline int ftrace_trace_task(struct trace_array *tr)
|
||||
{
|
||||
if (list_empty(&ftrace_pids))
|
||||
return 1;
|
||||
|
||||
return test_tsk_trace_trace(task);
|
||||
return !this_cpu_read(tr->trace_buffer.data->ftrace_ignore_pid);
|
||||
}
|
||||
extern int ftrace_is_dead(void);
|
||||
int ftrace_create_function_files(struct trace_array *tr,
|
||||
|
|
@ -855,8 +856,9 @@ void ftrace_init_global_array_ops(struct trace_array *tr);
|
|||
void ftrace_init_array_ops(struct trace_array *tr, ftrace_func_t func);
|
||||
void ftrace_reset_array_ops(struct trace_array *tr);
|
||||
int using_ftrace_ops_list_func(void);
|
||||
void ftrace_init_tracefs(struct trace_array *tr, struct dentry *d_tracer);
|
||||
#else
|
||||
static inline int ftrace_trace_task(struct task_struct *task)
|
||||
static inline int ftrace_trace_task(struct trace_array *tr)
|
||||
{
|
||||
return 1;
|
||||
}
|
||||
|
|
@ -871,6 +873,7 @@ static inline void ftrace_destroy_function_files(struct trace_array *tr) { }
|
|||
static inline __init void
|
||||
ftrace_init_global_array_ops(struct trace_array *tr) { }
|
||||
static inline void ftrace_reset_array_ops(struct trace_array *tr) { }
|
||||
static inline void ftrace_init_tracefs(struct trace_array *tr, struct dentry *d) { }
|
||||
/* ftace_func_t type is not defined, use macro instead of static inline */
|
||||
#define ftrace_init_array_ops(tr, func) do { } while (0)
|
||||
#endif /* CONFIG_FUNCTION_TRACER */
|
||||
|
|
|
|||
|
|
@ -43,7 +43,7 @@ static int allocate_ftrace_ops(struct trace_array *tr)
|
|||
|
||||
/* Currently only the non stack verision is supported */
|
||||
ops->func = function_trace_call;
|
||||
ops->flags = FTRACE_OPS_FL_RECURSION_SAFE;
|
||||
ops->flags = FTRACE_OPS_FL_RECURSION_SAFE | FTRACE_OPS_FL_PID;
|
||||
|
||||
tr->ops = ops;
|
||||
ops->private = tr;
|
||||
|
|
|
|||
|
|
@ -319,7 +319,7 @@ int trace_graph_entry(struct ftrace_graph_ent *trace)
|
|||
int cpu;
|
||||
int pc;
|
||||
|
||||
if (!ftrace_trace_task(current))
|
||||
if (!ftrace_trace_task(tr))
|
||||
return 0;
|
||||
|
||||
/* trace it when it is-nested-in or is a function enabled. */
|
||||
|
|
|
|||
Loading…
Reference in a new issue