tracing/uprobes: Use dyn_event framework for uprobe events

Use dyn_event framework for uprobe events. This shows
uprobe events on "dynamic_events" file.
User can also define new uprobe events via dynamic_events.

Link: http://lkml.kernel.org/r/154140858481.17322.9091293846515154065.stgit@devbox

Reviewed-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
This commit is contained in:
Masami Hiramatsu 2018-11-05 18:03:04 +09:00 committed by Steven Rostedt (VMware)
parent 6212dd2968
commit 0597c49c69
3 changed files with 157 additions and 134 deletions

View File

@ -18,6 +18,10 @@ current_tracer. Instead of that, add probe points via
However unlike kprobe-event tracer, the uprobe event interface expects the
user to calculate the offset of the probepoint in the object.
You can also use /sys/kernel/debug/tracing/dynamic_events instead of
uprobe_events. That interface will provide unified access to other
dynamic events too.
Synopsis of uprobe_tracer
-------------------------
::

View File

@ -501,6 +501,7 @@ config UPROBE_EVENTS
depends on PERF_EVENTS
select UPROBES
select PROBE_EVENTS
select DYNAMIC_EVENTS
select TRACING
default y
help

View File

@ -7,6 +7,7 @@
*/
#define pr_fmt(fmt) "trace_kprobe: " fmt
#include <linux/ctype.h>
#include <linux/module.h>
#include <linux/uaccess.h>
#include <linux/uprobes.h>
@ -14,6 +15,7 @@
#include <linux/string.h>
#include <linux/rculist.h>
#include "trace_dynevent.h"
#include "trace_probe.h"
#include "trace_probe_tmpl.h"
@ -37,11 +39,26 @@ struct trace_uprobe_filter {
struct list_head perf_events;
};
static int trace_uprobe_create(int argc, const char **argv);
static int trace_uprobe_show(struct seq_file *m, struct dyn_event *ev);
static int trace_uprobe_release(struct dyn_event *ev);
static bool trace_uprobe_is_busy(struct dyn_event *ev);
static bool trace_uprobe_match(const char *system, const char *event,
struct dyn_event *ev);
static struct dyn_event_operations trace_uprobe_ops = {
.create = trace_uprobe_create,
.show = trace_uprobe_show,
.is_busy = trace_uprobe_is_busy,
.free = trace_uprobe_release,
.match = trace_uprobe_match,
};
/*
* uprobe event core functions
*/
struct trace_uprobe {
struct list_head list;
struct dyn_event devent;
struct trace_uprobe_filter filter;
struct uprobe_consumer consumer;
struct path path;
@ -53,6 +70,25 @@ struct trace_uprobe {
struct trace_probe tp;
};
static bool is_trace_uprobe(struct dyn_event *ev)
{
return ev->ops == &trace_uprobe_ops;
}
static struct trace_uprobe *to_trace_uprobe(struct dyn_event *ev)
{
return container_of(ev, struct trace_uprobe, devent);
}
/**
* for_each_trace_uprobe - iterate over the trace_uprobe list
* @pos: the struct trace_uprobe * for each entry
* @dpos: the struct dyn_event * to use as a loop cursor
*/
#define for_each_trace_uprobe(pos, dpos) \
for_each_dyn_event(dpos) \
if (is_trace_uprobe(dpos) && (pos = to_trace_uprobe(dpos)))
#define SIZEOF_TRACE_UPROBE(n) \
(offsetof(struct trace_uprobe, tp.args) + \
(sizeof(struct probe_arg) * (n)))
@ -60,9 +96,6 @@ struct trace_uprobe {
static int register_uprobe_event(struct trace_uprobe *tu);
static int unregister_uprobe_event(struct trace_uprobe *tu);
static DEFINE_MUTEX(uprobe_lock);
static LIST_HEAD(uprobe_list);
struct uprobe_dispatch_data {
struct trace_uprobe *tu;
unsigned long bp_addr;
@ -209,6 +242,22 @@ static inline bool is_ret_probe(struct trace_uprobe *tu)
return tu->consumer.ret_handler != NULL;
}
static bool trace_uprobe_is_busy(struct dyn_event *ev)
{
struct trace_uprobe *tu = to_trace_uprobe(ev);
return trace_probe_is_enabled(&tu->tp);
}
static bool trace_uprobe_match(const char *system, const char *event,
struct dyn_event *ev)
{
struct trace_uprobe *tu = to_trace_uprobe(ev);
return strcmp(trace_event_name(&tu->tp.call), event) == 0 &&
(!system || strcmp(tu->tp.call.class->system, system) == 0);
}
/*
* Allocate new trace_uprobe and initialize it (including uprobes).
*/
@ -236,7 +285,7 @@ alloc_trace_uprobe(const char *group, const char *event, int nargs, bool is_ret)
if (!tu->tp.class.system)
goto error;
INIT_LIST_HEAD(&tu->list);
dyn_event_init(&tu->devent, &trace_uprobe_ops);
INIT_LIST_HEAD(&tu->tp.files);
tu->consumer.handler = uprobe_dispatcher;
if (is_ret)
@ -255,6 +304,9 @@ static void free_trace_uprobe(struct trace_uprobe *tu)
{
int i;
if (!tu)
return;
for (i = 0; i < tu->tp.nr_args; i++)
traceprobe_free_probe_arg(&tu->tp.args[i]);
@ -267,9 +319,10 @@ static void free_trace_uprobe(struct trace_uprobe *tu)
static struct trace_uprobe *find_probe_event(const char *event, const char *group)
{
struct dyn_event *pos;
struct trace_uprobe *tu;
list_for_each_entry(tu, &uprobe_list, list)
for_each_trace_uprobe(tu, pos)
if (strcmp(trace_event_name(&tu->tp.call), event) == 0 &&
strcmp(tu->tp.call.class->system, group) == 0)
return tu;
@ -277,7 +330,7 @@ static struct trace_uprobe *find_probe_event(const char *event, const char *grou
return NULL;
}
/* Unregister a trace_uprobe and probe_event: call with locking uprobe_lock */
/* Unregister a trace_uprobe and probe_event */
static int unregister_trace_uprobe(struct trace_uprobe *tu)
{
int ret;
@ -286,7 +339,7 @@ static int unregister_trace_uprobe(struct trace_uprobe *tu)
if (ret)
return ret;
list_del(&tu->list);
dyn_event_remove(&tu->devent);
free_trace_uprobe(tu);
return 0;
}
@ -302,13 +355,14 @@ static int unregister_trace_uprobe(struct trace_uprobe *tu)
*/
static struct trace_uprobe *find_old_trace_uprobe(struct trace_uprobe *new)
{
struct dyn_event *pos;
struct trace_uprobe *tmp, *old = NULL;
struct inode *new_inode = d_real_inode(new->path.dentry);
old = find_probe_event(trace_event_name(&new->tp.call),
new->tp.call.class->system);
list_for_each_entry(tmp, &uprobe_list, list) {
for_each_trace_uprobe(tmp, pos) {
if ((old ? old != tmp : true) &&
new_inode == d_real_inode(tmp->path.dentry) &&
new->offset == tmp->offset &&
@ -326,7 +380,7 @@ static int register_trace_uprobe(struct trace_uprobe *tu)
struct trace_uprobe *old_tu;
int ret;
mutex_lock(&uprobe_lock);
mutex_lock(&event_mutex);
/* register as an event */
old_tu = find_old_trace_uprobe(tu);
@ -348,10 +402,10 @@ static int register_trace_uprobe(struct trace_uprobe *tu)
goto end;
}
list_add_tail(&tu->list, &uprobe_list);
dyn_event_add(&tu->devent);
end:
mutex_unlock(&uprobe_lock);
mutex_unlock(&event_mutex);
return ret;
}
@ -362,91 +416,49 @@ static int register_trace_uprobe(struct trace_uprobe *tu)
*
* - Remove uprobe: -:[GRP/]EVENT
*/
static int create_trace_uprobe(int argc, char **argv)
static int trace_uprobe_create(int argc, const char **argv)
{
struct trace_uprobe *tu;
char *arg, *event, *group, *filename, *rctr, *rctr_end;
const char *event = NULL, *group = UPROBE_EVENT_SYSTEM;
char *arg, *filename, *rctr, *rctr_end, *tmp;
char buf[MAX_EVENT_NAME_LEN];
struct path path;
unsigned long offset, ref_ctr_offset;
bool is_delete, is_return;
bool is_return = false;
int i, ret;
ret = 0;
is_delete = false;
is_return = false;
event = NULL;
group = NULL;
ref_ctr_offset = 0;
/* argc must be >= 1 */
if (argv[0][0] == '-')
is_delete = true;
else if (argv[0][0] == 'r')
if (argv[0][0] == 'r')
is_return = true;
else if (argv[0][0] != 'p') {
pr_info("Probe definition must be started with 'p', 'r' or '-'.\n");
return -EINVAL;
}
else if (argv[0][0] != 'p' || argc < 2)
return -ECANCELED;
if (argv[0][1] == ':') {
if (argv[0][1] == ':')
event = &argv[0][2];
arg = strchr(event, '/');
if (arg) {
group = event;
event = arg + 1;
event[-1] = '\0';
if (!strchr(argv[1], '/'))
return -ECANCELED;
if (strlen(group) == 0) {
pr_info("Group name is not specified\n");
return -EINVAL;
}
}
if (strlen(event) == 0) {
pr_info("Event name is not specified\n");
return -EINVAL;
}
}
if (!group)
group = UPROBE_EVENT_SYSTEM;
filename = kstrdup(argv[1], GFP_KERNEL);
if (!filename)
return -ENOMEM;
if (is_delete) {
int ret;
if (!event) {
pr_info("Delete command needs an event name.\n");
return -EINVAL;
}
mutex_lock(&uprobe_lock);
tu = find_probe_event(event, group);
if (!tu) {
mutex_unlock(&uprobe_lock);
pr_info("Event %s/%s doesn't exist.\n", group, event);
return -ENOENT;
}
/* delete an event */
ret = unregister_trace_uprobe(tu);
mutex_unlock(&uprobe_lock);
return ret;
}
if (argc < 2) {
pr_info("Probe point is not specified.\n");
return -EINVAL;
}
/* Find the last occurrence, in case the path contains ':' too. */
arg = strrchr(argv[1], ':');
if (!arg)
return -EINVAL;
arg = strrchr(filename, ':');
if (!arg || !isdigit(arg[1])) {
kfree(filename);
return -ECANCELED;
}
*arg++ = '\0';
filename = argv[1];
ret = kern_path(filename, LOOKUP_FOLLOW, &path);
if (ret)
if (ret) {
kfree(filename);
return ret;
}
if (!d_is_reg(path.dentry)) {
ret = -EINVAL;
goto fail_address_parse;
@ -480,7 +492,11 @@ static int create_trace_uprobe(int argc, char **argv)
argv += 2;
/* setup a probe */
if (!event) {
if (event) {
ret = traceprobe_parse_event_name(&event, &group, buf);
if (ret)
goto fail_address_parse;
} else {
char *tail;
char *ptr;
@ -508,18 +524,19 @@ static int create_trace_uprobe(int argc, char **argv)
tu->offset = offset;
tu->ref_ctr_offset = ref_ctr_offset;
tu->path = path;
tu->filename = kstrdup(filename, GFP_KERNEL);
if (!tu->filename) {
pr_info("Failed to allocate filename.\n");
ret = -ENOMEM;
goto error;
}
tu->filename = filename;
/* parse arguments */
for (i = 0; i < argc && i < MAX_TRACE_ARGS; i++) {
ret = traceprobe_parse_probe_arg(&tu->tp, i, argv[i],
tmp = kstrdup(argv[i], GFP_KERNEL);
if (!tmp) {
ret = -ENOMEM;
goto error;
}
ret = traceprobe_parse_probe_arg(&tu->tp, i, tmp,
is_return ? TPARG_FL_RETURN : 0);
kfree(tmp);
if (ret)
goto error;
}
@ -535,55 +552,35 @@ static int create_trace_uprobe(int argc, char **argv)
fail_address_parse:
path_put(&path);
kfree(filename);
pr_info("Failed to parse address or file.\n");
return ret;
}
static int cleanup_all_probes(void)
static int create_or_delete_trace_uprobe(int argc, char **argv)
{
struct trace_uprobe *tu;
int ret = 0;
int ret;
mutex_lock(&uprobe_lock);
/* Ensure no probe is in use. */
list_for_each_entry(tu, &uprobe_list, list)
if (trace_probe_is_enabled(&tu->tp)) {
ret = -EBUSY;
goto end;
}
while (!list_empty(&uprobe_list)) {
tu = list_entry(uprobe_list.next, struct trace_uprobe, list);
ret = unregister_trace_uprobe(tu);
if (ret)
break;
}
end:
mutex_unlock(&uprobe_lock);
return ret;
if (argv[0][0] == '-')
return dyn_event_release(argc, argv, &trace_uprobe_ops);
ret = trace_uprobe_create(argc, (const char **)argv);
return ret == -ECANCELED ? -EINVAL : ret;
}
static int trace_uprobe_release(struct dyn_event *ev)
{
struct trace_uprobe *tu = to_trace_uprobe(ev);
return unregister_trace_uprobe(tu);
}
/* Probes listing interfaces */
static void *probes_seq_start(struct seq_file *m, loff_t *pos)
static int trace_uprobe_show(struct seq_file *m, struct dyn_event *ev)
{
mutex_lock(&uprobe_lock);
return seq_list_start(&uprobe_list, *pos);
}
static void *probes_seq_next(struct seq_file *m, void *v, loff_t *pos)
{
return seq_list_next(v, &uprobe_list, pos);
}
static void probes_seq_stop(struct seq_file *m, void *v)
{
mutex_unlock(&uprobe_lock);
}
static int probes_seq_show(struct seq_file *m, void *v)
{
struct trace_uprobe *tu = v;
struct trace_uprobe *tu = to_trace_uprobe(ev);
char c = is_ret_probe(tu) ? 'r' : 'p';
int i;
@ -601,11 +598,21 @@ static int probes_seq_show(struct seq_file *m, void *v)
return 0;
}
static int probes_seq_show(struct seq_file *m, void *v)
{
struct dyn_event *ev = v;
if (!is_trace_uprobe(ev))
return 0;
return trace_uprobe_show(m, ev);
}
static const struct seq_operations probes_seq_op = {
.start = probes_seq_start,
.next = probes_seq_next,
.stop = probes_seq_stop,
.show = probes_seq_show
.start = dyn_event_seq_start,
.next = dyn_event_seq_next,
.stop = dyn_event_seq_stop,
.show = probes_seq_show
};
static int probes_open(struct inode *inode, struct file *file)
@ -613,7 +620,7 @@ static int probes_open(struct inode *inode, struct file *file)
int ret;
if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) {
ret = cleanup_all_probes();
ret = dyn_events_release_all(&trace_uprobe_ops);
if (ret)
return ret;
}
@ -624,7 +631,8 @@ static int probes_open(struct inode *inode, struct file *file)
static ssize_t probes_write(struct file *file, const char __user *buffer,
size_t count, loff_t *ppos)
{
return trace_parse_run_command(file, buffer, count, ppos, create_trace_uprobe);
return trace_parse_run_command(file, buffer, count, ppos,
create_or_delete_trace_uprobe);
}
static const struct file_operations uprobe_events_ops = {
@ -639,17 +647,22 @@ static const struct file_operations uprobe_events_ops = {
/* Probes profiling interfaces */
static int probes_profile_seq_show(struct seq_file *m, void *v)
{
struct trace_uprobe *tu = v;
struct dyn_event *ev = v;
struct trace_uprobe *tu;
if (!is_trace_uprobe(ev))
return 0;
tu = to_trace_uprobe(ev);
seq_printf(m, " %s %-44s %15lu\n", tu->filename,
trace_event_name(&tu->tp.call), tu->nhit);
return 0;
}
static const struct seq_operations profile_seq_op = {
.start = probes_seq_start,
.next = probes_seq_next,
.stop = probes_seq_stop,
.start = dyn_event_seq_start,
.next = dyn_event_seq_next,
.stop = dyn_event_seq_stop,
.show = probes_profile_seq_show
};
@ -1307,7 +1320,7 @@ static int register_uprobe_event(struct trace_uprobe *tu)
return -ENODEV;
}
ret = trace_add_event_call(call);
ret = trace_add_event_call_nolock(call);
if (ret) {
pr_info("Failed to register uprobe event: %s\n",
@ -1324,7 +1337,7 @@ static int unregister_uprobe_event(struct trace_uprobe *tu)
int ret;
/* tu->event is unregistered in trace_remove_event_call() */
ret = trace_remove_event_call(&tu->tp.call);
ret = trace_remove_event_call_nolock(&tu->tp.call);
if (ret)
return ret;
kfree(tu->tp.call.print_fmt);
@ -1351,7 +1364,7 @@ create_local_trace_uprobe(char *name, unsigned long offs,
}
/*
* local trace_kprobes are not added to probe_list, so they are never
* local trace_kprobes are not added to dyn_event, so they are never
* searched in find_trace_kprobe(). Therefore, there is no concern of
* duplicated name "DUMMY_EVENT" here.
*/
@ -1399,6 +1412,11 @@ void destroy_local_trace_uprobe(struct trace_event_call *event_call)
static __init int init_uprobe_trace(void)
{
struct dentry *d_tracer;
int ret;
ret = dyn_event_register(&trace_uprobe_ops);
if (ret)
return ret;
d_tracer = tracing_init_dentry();
if (IS_ERR(d_tracer))