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) 2016-04-22 18:11:33 -04:00 committed by Steven Rostedt
parent 76c813e266
commit 345ddcc882
5 changed files with 158 additions and 195 deletions

View file

@ -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);
@ -5324,134 +5325,46 @@ 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;
struct trace_array *tr = data;
struct trace_pid_list *pid_list;
pid_list = rcu_dereference_sched(tr->function_pids);
this_cpu_write(tr->trace_buffer.data->ftrace_ignore_pid,
trace_ignore_this_task(pid_list, next));
}
static void clear_ftrace_pids(struct trace_array *tr)
{
struct trace_pid_list *pid_list;
int cpu;
get_online_cpus();
for_each_online_cpu(cpu) {
p = idle_task(cpu);
clear_tsk_trace_trace(p);
}
put_online_cpus();
pid_list = rcu_dereference_protected(tr->function_pids,
lockdep_is_held(&ftrace_lock));
if (!pid_list)
return;
unregister_trace_sched_switch(ftrace_filter_pid_sched_switch_probe, tr);
for_each_possible_cpu(cpu)
per_cpu_ptr(tr->trace_buffer.data, cpu)->ftrace_ignore_pid = false;
rcu_assign_pointer(tr->function_pids, NULL);
/* Wait till all users are no longer using pid filtering */
synchronize_sched();
trace_free_pid_list(pid_list);
}
static void set_ftrace_swapper(void)
static void ftrace_pid_reset(struct trace_array *tr)
{
struct task_struct *p;
int cpu;
get_online_cpus();
for_each_online_cpu(cpu) {
p = idle_task(cpu);
set_tsk_trace_trace(p);
}
put_online_cpus();
}
static void clear_ftrace_pid(struct pid *pid)
{
struct task_struct *p;
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();
put_pid(pid);
}
static void set_ftrace_pid(struct pid *pid)
{
struct task_struct *p;
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();
}
static void clear_ftrace_pid_task(struct pid *pid)
{
if (pid == ftrace_swapper_pid)
clear_ftrace_swapper();
else
clear_ftrace_pid(pid);
}
static void set_ftrace_pid_task(struct pid *pid)
{
if (pid == ftrace_swapper_pid)
set_ftrace_swapper();
else
set_ftrace_pid(pid);
}
static int ftrace_pid_add(int p)
{
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);
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);
}
clear_ftrace_pids(tr);
ftrace_update_pid_func();
ftrace_startup_all(0);
@ -5459,44 +5372,52 @@ static void ftrace_pid_reset(void)
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);
return seq_list_start(&ftrace_pids, *pos);
if (!pid_list)
return !(*pos) ? FTRACE_NO_PIDS : NULL;
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);
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);
buf[cnt] = 0;
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);
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;
ftrace_init_dyn_tracefs(d_tracer);
/* Only the top level directory has the dyn_tracefs and profile */
if (tr->flags & TRACE_ARRAY_FL_GLOBAL) {
ftrace_init_dyn_tracefs(d_tracer);
ftrace_profile_tracefs(d_tracer);
}
trace_create_file("set_ftrace_pid", 0644, d_tracer,
NULL, &ftrace_pid_fops);
ftrace_profile_tracefs(d_tracer);
return 0;
tr, &ftrace_pid_fops);
}
fs_initcall(ftrace_init_tracefs);
/**
* ftrace_kill - kill ftrace

View file

@ -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)

View file

@ -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 */

View file

@ -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;

View file

@ -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. */