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Commit 345ddcc8 authored by Steven Rostedt (Red Hat)'s avatar Steven Rostedt (Red Hat) Committed by Steven Rostedt
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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: default avatarSteven Rostedt <rostedt@goodmis.org>
parent 76c813e2

kernel/trace/ftrace.c

+136 −177
Original line number Diff line number Diff line
@@ -89,16 +89,16 @@ struct ftrace_ops *function_trace_op __read_mostly = &ftrace_list_end; 
/* What to set function_trace_op to */

static struct ftrace_ops *set_function_trace_op;



/* List for set_ftrace_pid's pids. */

LIST_HEAD(ftrace_pids);

struct ftrace_pid {

	struct list_head list;

	struct pid *pid;

};



static bool ftrace_pids_enabled(void)

static bool ftrace_pids_enabled(struct ftrace_ops *ops)

{

	return !list_empty(&ftrace_pids);

	struct trace_array *tr;



	if (!(ops->flags & FTRACE_OPS_FL_PID) || !ops->private)

		return false;



	tr = ops->private;



	return tr->function_pids != NULL;

}



static void ftrace_update_trampoline(struct ftrace_ops *ops);
@@ -179,7 +179,9 @@ int ftrace_nr_registered_ops(void) 
static void ftrace_pid_func(unsigned long ip, unsigned long parent_ip,

			    struct ftrace_ops *op, struct pt_regs *regs)

{

	if (!test_tsk_trace_trace(current))

	struct trace_array *tr = op->private;



	if (tr && this_cpu_read(tr->trace_buffer.data->ftrace_ignore_pid))

		return;



	op->saved_func(ip, parent_ip, op, regs);
@@ -417,7 +419,7 @@ static int __register_ftrace_function(struct ftrace_ops *ops) 
	/* Always save the function, and reset at unregistering */

	ops->saved_func = ops->func;



	if (ops->flags & FTRACE_OPS_FL_PID && ftrace_pids_enabled())

	if (ftrace_pids_enabled(ops))

		ops->func = ftrace_pid_func;



	ftrace_update_trampoline(ops);
@@ -450,7 +452,6 @@ static int __unregister_ftrace_function(struct ftrace_ops *ops) 


static void ftrace_update_pid_func(void)

{

	bool enabled = ftrace_pids_enabled();

	struct ftrace_ops *op;



	/* Only do something if we are tracing something */
@@ -459,8 +460,8 @@ static void ftrace_update_pid_func(void) 


	do_for_each_ftrace_op(op, ftrace_ops_list) {

		if (op->flags & FTRACE_OPS_FL_PID) {

			op->func = enabled ? ftrace_pid_func :

				op->saved_func;

			op->func = ftrace_pids_enabled(op) ?

				ftrace_pid_func : op->saved_func;

			ftrace_update_trampoline(op);

		}

	} while_for_each_ftrace_op(op);
@@ -5324,179 +5325,99 @@ ftrace_func_t ftrace_ops_get_func(struct ftrace_ops *ops) 
	return ops->func;

}



static void clear_ftrace_swapper(void)

static void

ftrace_filter_pid_sched_switch_probe(void *data, bool preempt,

		    struct task_struct *prev, struct task_struct *next)

{

	struct task_struct *p;

	int cpu;

	struct trace_array *tr = data;

	struct trace_pid_list *pid_list;



	get_online_cpus();

	for_each_online_cpu(cpu) {

		p = idle_task(cpu);

		clear_tsk_trace_trace(p);

	}

	put_online_cpus();

}



static void set_ftrace_swapper(void)

{

	struct task_struct *p;

	int cpu;

	pid_list = rcu_dereference_sched(tr->function_pids);



	get_online_cpus();

	for_each_online_cpu(cpu) {

		p = idle_task(cpu);

		set_tsk_trace_trace(p);

	}

	put_online_cpus();

	this_cpu_write(tr->trace_buffer.data->ftrace_ignore_pid,

		       trace_ignore_this_task(pid_list, next));

}



static void clear_ftrace_pid(struct pid *pid)

static void clear_ftrace_pids(struct trace_array *tr)

{

	struct task_struct *p;

	struct trace_pid_list *pid_list;

	int cpu;



	rcu_read_lock();

	do_each_pid_task(pid, PIDTYPE_PID, p) {

		clear_tsk_trace_trace(p);

	} while_each_pid_task(pid, PIDTYPE_PID, p);

	rcu_read_unlock();

	pid_list = rcu_dereference_protected(tr->function_pids,

					     lockdep_is_held(&ftrace_lock));

	if (!pid_list)

		return;



	put_pid(pid);

}

	unregister_trace_sched_switch(ftrace_filter_pid_sched_switch_probe, tr);



static void set_ftrace_pid(struct pid *pid)

{

	struct task_struct *p;

	for_each_possible_cpu(cpu)

		per_cpu_ptr(tr->trace_buffer.data, cpu)->ftrace_ignore_pid = false;



	rcu_read_lock();

	do_each_pid_task(pid, PIDTYPE_PID, p) {

		set_tsk_trace_trace(p);

	} while_each_pid_task(pid, PIDTYPE_PID, p);

	rcu_read_unlock();

}

	rcu_assign_pointer(tr->function_pids, NULL);



static void clear_ftrace_pid_task(struct pid *pid)

{

	if (pid == ftrace_swapper_pid)

		clear_ftrace_swapper();

	else

		clear_ftrace_pid(pid);

}

	/* Wait till all users are no longer using pid filtering */

	synchronize_sched();



static void set_ftrace_pid_task(struct pid *pid)

{

	if (pid == ftrace_swapper_pid)

		set_ftrace_swapper();

	else

		set_ftrace_pid(pid);

	trace_free_pid_list(pid_list);

}



static int ftrace_pid_add(int p)

static void ftrace_pid_reset(struct trace_array *tr)

{

	struct pid *pid;

	struct ftrace_pid *fpid;

	int ret = -EINVAL;



	mutex_lock(&ftrace_lock);



	if (!p)

		pid = ftrace_swapper_pid;

	else

		pid = find_get_pid(p);



	if (!pid)

		goto out;



	ret = 0;



	list_for_each_entry(fpid, &ftrace_pids, list)

		if (fpid->pid == pid)

			goto out_put;



	ret = -ENOMEM;



	fpid = kmalloc(sizeof(*fpid), GFP_KERNEL);

	if (!fpid)

		goto out_put;



	list_add(&fpid->list, &ftrace_pids);

	fpid->pid = pid;



	set_ftrace_pid_task(pid);

	clear_ftrace_pids(tr);



	ftrace_update_pid_func();



	ftrace_startup_all(0);



	mutex_unlock(&ftrace_lock);

	return 0;



out_put:

	if (pid != ftrace_swapper_pid)

		put_pid(pid);



out:

	mutex_unlock(&ftrace_lock);

	return ret;

}



static void ftrace_pid_reset(void)

{

	struct ftrace_pid *fpid, *safe;



	mutex_lock(&ftrace_lock);

	list_for_each_entry_safe(fpid, safe, &ftrace_pids, list) {

		struct pid *pid = fpid->pid;



		clear_ftrace_pid_task(pid);



		list_del(&fpid->list);

		kfree(fpid);

	}



	ftrace_update_pid_func();

	ftrace_startup_all(0);



	mutex_unlock(&ftrace_lock);

}

/* Greater than any max PID */

#define FTRACE_NO_PIDS		(void *)(PID_MAX_LIMIT + 1)



static void *fpid_start(struct seq_file *m, loff_t *pos)

	__acquires(RCU)

{

	struct trace_pid_list *pid_list;

	struct trace_array *tr = m->private;



	mutex_lock(&ftrace_lock);

	rcu_read_lock_sched();



	if (!ftrace_pids_enabled() && (!*pos))

		return (void *) 1;

	pid_list = rcu_dereference_sched(tr->function_pids);



	if (!pid_list)

		return !(*pos) ? FTRACE_NO_PIDS : NULL;



	return seq_list_start(&ftrace_pids, *pos);

	return trace_pid_start(pid_list, pos);

}



static void *fpid_next(struct seq_file *m, void *v, loff_t *pos)

{

	if (v == (void *)1)

	struct trace_array *tr = m->private;

	struct trace_pid_list *pid_list = rcu_dereference_sched(tr->function_pids);



	if (v == FTRACE_NO_PIDS)

		return NULL;



	return seq_list_next(v, &ftrace_pids, pos);

	return trace_pid_next(pid_list, v, pos);

}



static void fpid_stop(struct seq_file *m, void *p)

	__releases(RCU)

{

	rcu_read_unlock_sched();

	mutex_unlock(&ftrace_lock);

}



static int fpid_show(struct seq_file *m, void *v)

{

	const struct ftrace_pid *fpid = list_entry(v, struct ftrace_pid, list);



	if (v == (void *)1) {

	if (v == FTRACE_NO_PIDS) {

		seq_puts(m, "no pid\n");

		return 0;

	}



	if (fpid->pid == ftrace_swapper_pid)

		seq_puts(m, "swapper tasks\n");

	else

		seq_printf(m, "%u\n", pid_vnr(fpid->pid));



	return 0;

	return trace_pid_show(m, v);

}



static const struct seq_operations ftrace_pid_sops = {
@@ -5509,58 +5430,103 @@ static const struct seq_operations ftrace_pid_sops = { 
static int

ftrace_pid_open(struct inode *inode, struct file *file)

{

	struct trace_array *tr = inode->i_private;

	struct seq_file *m;

	int ret = 0;



	if (trace_array_get(tr) < 0)

		return -ENODEV;



	if ((file->f_mode & FMODE_WRITE) &&

	    (file->f_flags & O_TRUNC))

		ftrace_pid_reset();

		ftrace_pid_reset(tr);



	if (file->f_mode & FMODE_READ)

	ret = seq_open(file, &ftrace_pid_sops);

	if (ret < 0) {

		trace_array_put(tr);

	} else {

		m = file->private_data;

		/* copy tr over to seq ops */

		m->private = tr;

	}



	return ret;

}



static void ignore_task_cpu(void *data)

{

	struct trace_array *tr = data;

	struct trace_pid_list *pid_list;



	/*

	 * This function is called by on_each_cpu() while the

	 * event_mutex is held.

	 */

	pid_list = rcu_dereference_protected(tr->function_pids,

					     mutex_is_locked(&ftrace_lock));



	this_cpu_write(tr->trace_buffer.data->ftrace_ignore_pid,

		       trace_ignore_this_task(pid_list, current));

}



static ssize_t

ftrace_pid_write(struct file *filp, const char __user *ubuf,

		   size_t cnt, loff_t *ppos)

{

	char buf[64], *tmp;

	long val;

	int ret;

	struct seq_file *m = filp->private_data;

	struct trace_array *tr = m->private;

	struct trace_pid_list *filtered_pids = NULL;

	struct trace_pid_list *pid_list;

	ssize_t ret;



	if (cnt >= sizeof(buf))

		return -EINVAL;

	if (!cnt)

		return 0;



	if (copy_from_user(&buf, ubuf, cnt))

		return -EFAULT;

	mutex_lock(&ftrace_lock);



	filtered_pids = rcu_dereference_protected(tr->function_pids,

					     lockdep_is_held(&ftrace_lock));



	ret = trace_pid_write(filtered_pids, &pid_list, ubuf, cnt);

	if (ret < 0)

		goto out;



	rcu_assign_pointer(tr->function_pids, pid_list);



	buf[cnt] = 0;

	if (filtered_pids) {

		synchronize_sched();

		trace_free_pid_list(filtered_pids);

	} else if (pid_list) {

		/* Register a probe to set whether to ignore the tracing of a task */

		register_trace_sched_switch(ftrace_filter_pid_sched_switch_probe, tr);

	}



	/*

	 * Allow "echo > set_ftrace_pid" or "echo -n '' > set_ftrace_pid"

	 * to clean the filter quietly.

	 * Ignoring of pids is done at task switch. But we have to

	 * check for those tasks that are currently running.

	 * Always do this in case a pid was appended or removed.

	 */

	tmp = strstrip(buf);

	if (strlen(tmp) == 0)

		return 1;

	on_each_cpu(ignore_task_cpu, tr, 1);



	ret = kstrtol(tmp, 10, &val);

	if (ret < 0)

		return ret;

	ftrace_update_pid_func();

	ftrace_startup_all(0);

 out:

	mutex_unlock(&ftrace_lock);



	ret = ftrace_pid_add(val);

	if (ret > 0)

		*ppos += ret;



	return ret ? ret : cnt;

	return ret;

}



static int

ftrace_pid_release(struct inode *inode, struct file *file)

{

	if (file->f_mode & FMODE_READ)

		seq_release(inode, file);

	struct trace_array *tr = inode->i_private;



	return 0;

	trace_array_put(tr);



	return seq_release(inode, file);

}



static const struct file_operations ftrace_pid_fops = {
@@ -5571,24 +5537,17 @@ static const struct file_operations ftrace_pid_fops = { 
	.release	= ftrace_pid_release,

};



static __init int ftrace_init_tracefs(void)

void ftrace_init_tracefs(struct trace_array *tr, struct dentry *d_tracer)

{

	struct dentry *d_tracer;



	d_tracer = tracing_init_dentry();

	if (IS_ERR(d_tracer))

		return 0;



	/* Only the top level directory has the dyn_tracefs and profile */

	if (tr->flags & TRACE_ARRAY_FL_GLOBAL) {

		ftrace_init_dyn_tracefs(d_tracer);



	trace_create_file("set_ftrace_pid", 0644, d_tracer,

			    NULL, &ftrace_pid_fops);



		ftrace_profile_tracefs(d_tracer);

	}



	return 0;

	trace_create_file("set_ftrace_pid", 0644, d_tracer,

			    tr, &ftrace_pid_fops);

}

fs_initcall(ftrace_init_tracefs);



/**

 * ftrace_kill - kill ftrace

kernel/trace/trace.c

+1 −0
Original line number Diff line number Diff line
@@ -7233,6 +7233,7 @@ init_tracer_tracefs(struct trace_array *tr, struct dentry *d_tracer) 
	for_each_tracing_cpu(cpu)

		tracing_init_tracefs_percpu(tr, cpu);



	ftrace_init_tracefs(tr, d_tracer);

}



static struct vfsmount *trace_automount(void *ingore)

kernel/trace/trace.h

+9 −6
Original line number Diff line number Diff line
@@ -156,6 +156,9 @@ struct trace_array_cpu { 
	char			comm[TASK_COMM_LEN];



	bool			ignore_pid;

#ifdef CONFIG_FUNCTION_TRACER

	bool			ftrace_ignore_pid;

#endif

};



struct tracer;
@@ -247,6 +250,7 @@ struct trace_array { 
	int			ref;

#ifdef CONFIG_FUNCTION_TRACER

	struct ftrace_ops	*ops;

	struct trace_pid_list	__rcu *function_pids;

	/* function tracing enabled */

	int			function_enabled;

#endif
@@ -840,12 +844,9 @@ extern struct list_head ftrace_pids; 


#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 */

kernel/trace/trace_functions.c

+1 −1
Original line number Diff line number Diff line
@@ -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;

kernel/trace/trace_functions_graph.c

+1 −1
Original line number Diff line number Diff line
@@ -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. */