diff --git a/include/linux/trace_events.h b/include/linux/trace_events.h
index f85693bbcdc317e1bdcc693e63253be60787f23c..429fdfc3baf59e018d0e198062f894642af8a5bc 100644
--- a/include/linux/trace_events.h
+++ b/include/linux/trace_events.h
@@ -328,6 +328,7 @@ enum {
EVENT_FILE_FL_SOFT_DISABLED_BIT,
EVENT_FILE_FL_TRIGGER_MODE_BIT,
EVENT_FILE_FL_TRIGGER_COND_BIT,
+ EVENT_FILE_FL_PID_FILTER_BIT,
};
/*
@@ -341,6 +342,7 @@ enum {
* tracepoint may be enabled)
* TRIGGER_MODE - When set, invoke the triggers associated with the event
* TRIGGER_COND - When set, one or more triggers has an associated filter
+ * PID_FILTER - When set, the event is filtered based on pid
*/
enum {
EVENT_FILE_FL_ENABLED = (1 << EVENT_FILE_FL_ENABLED_BIT),
@@ -351,6 +353,7 @@ enum {
EVENT_FILE_FL_SOFT_DISABLED = (1 << EVENT_FILE_FL_SOFT_DISABLED_BIT),
EVENT_FILE_FL_TRIGGER_MODE = (1 << EVENT_FILE_FL_TRIGGER_MODE_BIT),
EVENT_FILE_FL_TRIGGER_COND = (1 << EVENT_FILE_FL_TRIGGER_COND_BIT),
+ EVENT_FILE_FL_PID_FILTER = (1 << EVENT_FILE_FL_PID_FILTER_BIT),
};
struct trace_event_file {
@@ -429,6 +432,8 @@ extern enum event_trigger_type event_triggers_call(struct trace_event_file *file
extern void event_triggers_post_call(struct trace_event_file *file,
enum event_trigger_type tt);
+bool trace_event_ignore_this_pid(struct trace_event_file *trace_file);
+
/**
* trace_trigger_soft_disabled - do triggers and test if soft disabled
* @file: The file pointer of the event to test
@@ -448,6 +453,8 @@ trace_trigger_soft_disabled(struct trace_event_file *file)
event_triggers_call(file, NULL);
if (eflags & EVENT_FILE_FL_SOFT_DISABLED)
return true;
+ if (eflags & EVENT_FILE_FL_PID_FILTER)
+ return trace_event_ignore_this_pid(file);
}
return false;
}
diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h
index 250481043bb531356b77aa723fb2d618e5a36301..89ffdaf3e3718b55db75e938394936d92d61b563 100644
--- a/kernel/trace/trace.h
+++ b/kernel/trace/trace.h
@@ -156,6 +156,8 @@ struct trace_array_cpu {
pid_t pid;
kuid_t uid;
char comm[TASK_COMM_LEN];
+
+ bool ignore_pid;
};
struct tracer;
diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c
index 2ad7014707eec009cc3bbc0af4e5565f45035bb6..ab07058e27c1d3f9d188387abd51bb2bec9ce86e 100644
--- a/kernel/trace/trace_events.c
+++ b/kernel/trace/trace_events.c
@@ -22,6 +22,8 @@
#include <linux/slab.h>
#include <linux/delay.h>
+#include <trace/events/sched.h>
+
#include <asm/setup.h>
#include "trace_output.h"
@@ -212,12 +214,32 @@ int trace_event_raw_init(struct trace_event_call *call)
}
EXPORT_SYMBOL_GPL(trace_event_raw_init);
+bool trace_event_ignore_this_pid(struct trace_event_file *trace_file)
+{
+ struct trace_array *tr = trace_file->tr;
+ struct trace_array_cpu *data;
+ struct trace_pid_list *pid_list;
+
+ pid_list = rcu_dereference_sched(tr->filtered_pids);
+ if (!pid_list)
+ return false;
+
+ data = this_cpu_ptr(tr->trace_buffer.data);
+
+ return data->ignore_pid;
+}
+EXPORT_SYMBOL_GPL(trace_event_ignore_this_pid);
+
void *trace_event_buffer_reserve(struct trace_event_buffer *fbuffer,
struct trace_event_file *trace_file,
unsigned long len)
{
struct trace_event_call *event_call = trace_file->event_call;
+ if ((trace_file->flags & EVENT_FILE_FL_PID_FILTER) &&
+ trace_event_ignore_this_pid(trace_file))
+ return NULL;
+
local_save_flags(fbuffer->flags);
fbuffer->pc = preempt_count();
fbuffer->trace_file = trace_file;
@@ -459,15 +481,114 @@ static int cmp_pid(const void *key, const void *elt)
return 1;
}
+static bool
+check_ignore_pid(struct trace_pid_list *filtered_pids, struct task_struct *task)
+{
+ pid_t search_pid;
+ pid_t *pid;
+
+ /*
+ * Return false, because if filtered_pids does not exist,
+ * all pids are good to trace.
+ */
+ if (!filtered_pids)
+ return false;
+
+ search_pid = task->pid;
+
+ pid = bsearch(&search_pid, filtered_pids->pids,
+ filtered_pids->nr_pids, sizeof(pid_t),
+ cmp_pid);
+ if (!pid)
+ return true;
+
+ return false;
+}
+
+static void
+event_filter_pid_sched_switch_probe_pre(void *data,
+ struct task_struct *prev, struct task_struct *next)
+{
+ struct trace_array *tr = data;
+ struct trace_pid_list *pid_list;
+
+ pid_list = rcu_dereference_sched(tr->filtered_pids);
+
+ this_cpu_write(tr->trace_buffer.data->ignore_pid,
+ check_ignore_pid(pid_list, prev) &&
+ check_ignore_pid(pid_list, next));
+}
+
+static void
+event_filter_pid_sched_switch_probe_post(void *data,
+ struct task_struct *prev, struct task_struct *next)
+{
+ struct trace_array *tr = data;
+ struct trace_pid_list *pid_list;
+
+ pid_list = rcu_dereference_sched(tr->filtered_pids);
+
+ this_cpu_write(tr->trace_buffer.data->ignore_pid,
+ check_ignore_pid(pid_list, next));
+}
+
+static void
+event_filter_pid_sched_wakeup_probe_pre(void *data, struct task_struct *task)
+{
+ struct trace_array *tr = data;
+ struct trace_pid_list *pid_list;
+
+ /* Nothing to do if we are already tracing */
+ if (!this_cpu_read(tr->trace_buffer.data->ignore_pid))
+ return;
+
+ pid_list = rcu_dereference_sched(tr->filtered_pids);
+
+ this_cpu_write(tr->trace_buffer.data->ignore_pid,
+ check_ignore_pid(pid_list, task));
+}
+
+static void
+event_filter_pid_sched_wakeup_probe_post(void *data, struct task_struct *task)
+{
+ struct trace_array *tr = data;
+ struct trace_pid_list *pid_list;
+
+ /* Nothing to do if we are not tracing */
+ if (this_cpu_read(tr->trace_buffer.data->ignore_pid))
+ return;
+
+ pid_list = rcu_dereference_sched(tr->filtered_pids);
+
+ /* Set tracing if current is enabled */
+ this_cpu_write(tr->trace_buffer.data->ignore_pid,
+ check_ignore_pid(pid_list, current));
+}
+
static void __ftrace_clear_event_pids(struct trace_array *tr)
{
struct trace_pid_list *pid_list;
+ struct trace_event_file *file;
+ int cpu;
pid_list = rcu_dereference_protected(tr->filtered_pids,
lockdep_is_held(&event_mutex));
if (!pid_list)
return;
+ unregister_trace_sched_switch(event_filter_pid_sched_switch_probe_pre, tr);
+ unregister_trace_sched_switch(event_filter_pid_sched_switch_probe_post, tr);
+
+ unregister_trace_sched_wakeup(event_filter_pid_sched_wakeup_probe_pre, tr);
+ unregister_trace_sched_wakeup(event_filter_pid_sched_wakeup_probe_post, tr);
+
+ list_for_each_entry(file, &tr->events, list) {
+ clear_bit(EVENT_FILE_FL_PID_FILTER_BIT, &file->flags);
+ }
+
+ for_each_possible_cpu(cpu)
+ per_cpu_ptr(tr->trace_buffer.data, cpu)->ignore_pid = false;
+
rcu_assign_pointer(tr->filtered_pids, NULL);
/* Wait till all users are no longer using pid filtering */
@@ -1429,13 +1550,14 @@ static int max_pids(struct trace_pid_list *pid_list)
}
static ssize_t
-ftrace_event_pid_write(struct file *file, const char __user *ubuf,
+ftrace_event_pid_write(struct file *filp, const char __user *ubuf,
size_t cnt, loff_t *ppos)
{
- struct seq_file *m = file->private_data;
+ 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 = NULL;
+ struct trace_event_file *file;
struct trace_parser parser;
unsigned long val;
loff_t this_pos;
@@ -1564,15 +1686,35 @@ ftrace_event_pid_write(struct file *file, const char __user *ubuf,
rcu_assign_pointer(tr->filtered_pids, pid_list);
- mutex_unlock(&event_mutex);
+ list_for_each_entry(file, &tr->events, list) {
+ set_bit(EVENT_FILE_FL_PID_FILTER_BIT, &file->flags);
+ }
if (filtered_pids) {
synchronize_sched();
free_pages((unsigned long)filtered_pids->pids, filtered_pids->order);
kfree(filtered_pids);
+ } else {
+ /*
+ * Register a probe that is called before all other probes
+ * to set ignore_pid if next or prev do not match.
+ * Register a probe this is called after all other probes
+ * to only keep ignore_pid set if next pid matches.
+ */
+ register_trace_prio_sched_switch(event_filter_pid_sched_switch_probe_pre,
+ tr, INT_MAX);
+ register_trace_prio_sched_switch(event_filter_pid_sched_switch_probe_post,
+ tr, 0);
+
+ register_trace_prio_sched_wakeup(event_filter_pid_sched_wakeup_probe_pre,
+ tr, INT_MAX);
+ register_trace_prio_sched_wakeup(event_filter_pid_sched_wakeup_probe_post,
+ tr, 0);
}
+ mutex_unlock(&event_mutex);
+
ret = read;
*ppos += read;