mirror of https://gitee.com/openkylin/linux.git
tracing/kprobes: Support ftrace_event_file base multibuffer
Support multi-buffer on kprobe-based dynamic events by using ftrace_event_file. Link: http://lkml.kernel.org/r/20130509054449.30398.88343.stgit@mhiramat-M0-7522 Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: Tom Zanussi <tom.zanussi@intel.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com> Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
This commit is contained in:
Masami Hiramatsu
Steven Rostedt
parent
2b106aabe6
commit
41a7dd420c
|
|
@ -27,7 +27,6 @@
|
|||
/**
|
||||
* Kprobe event core functions
|
||||
*/
|
||||
|
||||
struct trace_probe {
|
||||
struct list_head list;
|
||||
struct kretprobe rp; /* Use rp.kp for kprobe use */
|
||||
|
|
@ -36,6 +35,7 @@ struct trace_probe {
|
|||
const char *symbol; /* symbol name */
|
||||
struct ftrace_event_class class;
|
||||
struct ftrace_event_call call;
|
||||
struct ftrace_event_file **files;
|
||||
ssize_t size; /* trace entry size */
|
||||
unsigned int nr_args;
|
||||
struct probe_arg args[];
|
||||
|
|
@ -183,12 +183,57 @@ static struct trace_probe *find_trace_probe(const char *event,
|
|||
return NULL;
|
||||
}
|
||||
|
||||
/* Enable trace_probe - @flag must be TP_FLAG_TRACE or TP_FLAG_PROFILE */
|
||||
static int enable_trace_probe(struct trace_probe *tp, int flag)
|
||||
static int trace_probe_nr_files(struct trace_probe *tp)
|
||||
{
|
||||
struct ftrace_event_file **file = tp->files;
|
||||
int ret = 0;
|
||||
|
||||
if (file)
|
||||
while (*(file++))
|
||||
ret++;
|
||||
|
||||
return ret;
|
||||
}
|
||||
|
||||
static DEFINE_MUTEX(probe_enable_lock);
|
||||
|
||||
/*
|
||||
* Enable trace_probe
|
||||
* if the file is NULL, enable "perf" handler, or enable "trace" handler.
|
||||
*/
|
||||
static int
|
||||
enable_trace_probe(struct trace_probe *tp, struct ftrace_event_file *file)
|
||||
{
|
||||
int ret = 0;
|
||||
|
||||
tp->flags |= flag;
|
||||
mutex_lock(&probe_enable_lock);
|
||||
|
||||
if (file) {
|
||||
struct ftrace_event_file **new, **old = tp->files;
|
||||
int n = trace_probe_nr_files(tp);
|
||||
|
||||
/* 1 is for new one and 1 is for stopper */
|
||||
new = kzalloc((n + 2) * sizeof(struct ftrace_event_file *),
|
||||
GFP_KERNEL);
|
||||
if (!new) {
|
||||
ret = -ENOMEM;
|
||||
goto out_unlock;
|
||||
}
|
||||
memcpy(new, old, n * sizeof(struct ftrace_event_file *));
|
||||
new[n] = file;
|
||||
/* The last one keeps a NULL */
|
||||
|
||||
rcu_assign_pointer(tp->files, new);
|
||||
tp->flags |= TP_FLAG_TRACE;
|
||||
|
||||
if (old) {
|
||||
/* Make sure the probe is done with old files */
|
||||
synchronize_sched();
|
||||
kfree(old);
|
||||
}
|
||||
} else
|
||||
tp->flags |= TP_FLAG_PROFILE;
|
||||
|
||||
if (trace_probe_is_enabled(tp) && trace_probe_is_registered(tp) &&
|
||||
!trace_probe_has_gone(tp)) {
|
||||
if (trace_probe_is_return(tp))
|
||||
|
|
@ -197,19 +242,83 @@ static int enable_trace_probe(struct trace_probe *tp, int flag)
|
|||
ret = enable_kprobe(&tp->rp.kp);
|
||||
}
|
||||
|
||||
out_unlock:
|
||||
mutex_unlock(&probe_enable_lock);
|
||||
|
||||
return ret;
|
||||
}
|
||||
|
||||
/* Disable trace_probe - @flag must be TP_FLAG_TRACE or TP_FLAG_PROFILE */
|
||||
static void disable_trace_probe(struct trace_probe *tp, int flag)
|
||||
static int
|
||||
trace_probe_file_index(struct trace_probe *tp, struct ftrace_event_file *file)
|
||||
{
|
||||
tp->flags &= ~flag;
|
||||
int i;
|
||||
|
||||
if (tp->files) {
|
||||
for (i = 0; tp->files[i]; i++)
|
||||
if (tp->files[i] == file)
|
||||
return i;
|
||||
}
|
||||
|
||||
return -1;
|
||||
}
|
||||
|
||||
/*
|
||||
* Disable trace_probe
|
||||
* if the file is NULL, disable "perf" handler, or disable "trace" handler.
|
||||
*/
|
||||
static int
|
||||
disable_trace_probe(struct trace_probe *tp, struct ftrace_event_file *file)
|
||||
{
|
||||
int ret = 0;
|
||||
|
||||
mutex_lock(&probe_enable_lock);
|
||||
|
||||
if (file) {
|
||||
struct ftrace_event_file **new, **old = tp->files;
|
||||
int n = trace_probe_nr_files(tp);
|
||||
int i, j;
|
||||
|
||||
if (n == 0 || trace_probe_file_index(tp, file) < 0) {
|
||||
ret = -EINVAL;
|
||||
goto out_unlock;
|
||||
}
|
||||
|
||||
if (n == 1) { /* Remove the last file */
|
||||
tp->flags &= ~TP_FLAG_TRACE;
|
||||
new = NULL;
|
||||
} else {
|
||||
new = kzalloc(n * sizeof(struct ftrace_event_file *),
|
||||
GFP_KERNEL);
|
||||
if (!new) {
|
||||
ret = -ENOMEM;
|
||||
goto out_unlock;
|
||||
}
|
||||
|
||||
/* This copy & check loop copies the NULL stopper too */
|
||||
for (i = 0, j = 0; j < n && i < n + 1; i++)
|
||||
if (old[i] != file)
|
||||
new[j++] = old[i];
|
||||
}
|
||||
|
||||
rcu_assign_pointer(tp->files, new);
|
||||
|
||||
/* Make sure the probe is done with old files */
|
||||
synchronize_sched();
|
||||
kfree(old);
|
||||
} else
|
||||
tp->flags &= ~TP_FLAG_PROFILE;
|
||||
|
||||
if (!trace_probe_is_enabled(tp) && trace_probe_is_registered(tp)) {
|
||||
if (trace_probe_is_return(tp))
|
||||
disable_kretprobe(&tp->rp);
|
||||
else
|
||||
disable_kprobe(&tp->rp.kp);
|
||||
}
|
||||
|
||||
out_unlock:
|
||||
mutex_unlock(&probe_enable_lock);
|
||||
|
||||
return ret;
|
||||
}
|
||||
|
||||
/* Internal register function - just handle k*probes and flags */
|
||||
|
|
@ -724,7 +833,8 @@ static __kprobes void store_trace_args(int ent_size, struct trace_probe *tp,
|
|||
|
||||
/* Kprobe handler */
|
||||
static __kprobes void
|
||||
kprobe_trace_func(struct trace_probe *tp, struct pt_regs *regs)
|
||||
__kprobe_trace_func(struct trace_probe *tp, struct pt_regs *regs,
|
||||
struct ftrace_event_file *ftrace_file)
|
||||
{
|
||||
struct kprobe_trace_entry_head *entry;
|
||||
struct ring_buffer_event *event;
|
||||
|
|
@ -733,13 +843,16 @@ kprobe_trace_func(struct trace_probe *tp, struct pt_regs *regs)
|
|||
unsigned long irq_flags;
|
||||
struct ftrace_event_call *call = &tp->call;
|
||||
|
||||
WARN_ON(call != ftrace_file->event_call);
|
||||
|
||||
local_save_flags(irq_flags);
|
||||
pc = preempt_count();
|
||||
|
||||
dsize = __get_data_size(tp, regs);
|
||||
size = sizeof(*entry) + tp->size + dsize;
|
||||
|
||||
event = trace_current_buffer_lock_reserve(&buffer, call->event.type,
|
||||
event = trace_event_buffer_lock_reserve(&buffer, ftrace_file,
|
||||
call->event.type,
|
||||
size, irq_flags, pc);
|
||||
if (!event)
|
||||
return;
|
||||
|
|
@ -753,10 +866,23 @@ kprobe_trace_func(struct trace_probe *tp, struct pt_regs *regs)
|
|||
irq_flags, pc, regs);
|
||||
}
|
||||
|
||||
static __kprobes void
|
||||
kprobe_trace_func(struct trace_probe *tp, struct pt_regs *regs)
|
||||
{
|
||||
struct ftrace_event_file **file = tp->files;
|
||||
|
||||
/* Note: preempt is already disabled around the kprobe handler */
|
||||
while (*file) {
|
||||
__kprobe_trace_func(tp, regs, *file);
|
||||
file++;
|
||||
}
|
||||
}
|
||||
|
||||
/* Kretprobe handler */
|
||||
static __kprobes void
|
||||
kretprobe_trace_func(struct trace_probe *tp, struct kretprobe_instance *ri,
|
||||
struct pt_regs *regs)
|
||||
__kretprobe_trace_func(struct trace_probe *tp, struct kretprobe_instance *ri,
|
||||
struct pt_regs *regs,
|
||||
struct ftrace_event_file *ftrace_file)
|
||||
{
|
||||
struct kretprobe_trace_entry_head *entry;
|
||||
struct ring_buffer_event *event;
|
||||
|
|
@ -765,13 +891,16 @@ kretprobe_trace_func(struct trace_probe *tp, struct kretprobe_instance *ri,
|
|||
unsigned long irq_flags;
|
||||
struct ftrace_event_call *call = &tp->call;
|
||||
|
||||
WARN_ON(call != ftrace_file->event_call);
|
||||
|
||||
local_save_flags(irq_flags);
|
||||
pc = preempt_count();
|
||||
|
||||
dsize = __get_data_size(tp, regs);
|
||||
size = sizeof(*entry) + tp->size + dsize;
|
||||
|
||||
event = trace_current_buffer_lock_reserve(&buffer, call->event.type,
|
||||
event = trace_event_buffer_lock_reserve(&buffer, ftrace_file,
|
||||
call->event.type,
|
||||
size, irq_flags, pc);
|
||||
if (!event)
|
||||
return;
|
||||
|
|
@ -786,6 +915,19 @@ kretprobe_trace_func(struct trace_probe *tp, struct kretprobe_instance *ri,
|
|||
irq_flags, pc, regs);
|
||||
}
|
||||
|
||||
static __kprobes void
|
||||
kretprobe_trace_func(struct trace_probe *tp, struct kretprobe_instance *ri,
|
||||
struct pt_regs *regs)
|
||||
{
|
||||
struct ftrace_event_file **file = tp->files;
|
||||
|
||||
/* Note: preempt is already disabled around the kprobe handler */
|
||||
while (*file) {
|
||||
__kretprobe_trace_func(tp, ri, regs, *file);
|
||||
file++;
|
||||
}
|
||||
}
|
||||
|
||||
/* Event entry printers */
|
||||
enum print_line_t
|
||||
print_kprobe_event(struct trace_iterator *iter, int flags,
|
||||
|
|
@ -1041,20 +1183,19 @@ int kprobe_register(struct ftrace_event_call *event,
|
|||
enum trace_reg type, void *data)
|
||||
{
|
||||
struct trace_probe *tp = (struct trace_probe *)event->data;
|
||||
struct ftrace_event_file *file = data;
|
||||
|
||||
switch (type) {
|
||||
case TRACE_REG_REGISTER:
|
||||
return enable_trace_probe(tp, TP_FLAG_TRACE);
|
||||
return enable_trace_probe(tp, file);
|
||||
case TRACE_REG_UNREGISTER:
|
||||
disable_trace_probe(tp, TP_FLAG_TRACE);
|
||||
return 0;
|
||||
return disable_trace_probe(tp, file);
|
||||
|
||||
#ifdef CONFIG_PERF_EVENTS
|
||||
case TRACE_REG_PERF_REGISTER:
|
||||
return enable_trace_probe(tp, TP_FLAG_PROFILE);
|
||||
return enable_trace_probe(tp, NULL);
|
||||
case TRACE_REG_PERF_UNREGISTER:
|
||||
disable_trace_probe(tp, TP_FLAG_PROFILE);
|
||||
return 0;
|
||||
return disable_trace_probe(tp, NULL);
|
||||
case TRACE_REG_PERF_OPEN:
|
||||
case TRACE_REG_PERF_CLOSE:
|
||||
case TRACE_REG_PERF_ADD:
|
||||
|
|
@ -1190,11 +1331,24 @@ static __used int kprobe_trace_selftest_target(int a1, int a2, int a3,
|
|||
return a1 + a2 + a3 + a4 + a5 + a6;
|
||||
}
|
||||
|
||||
static struct ftrace_event_file *
|
||||
find_trace_probe_file(struct trace_probe *tp, struct trace_array *tr)
|
||||
{
|
||||
struct ftrace_event_file *file;
|
||||
|
||||
list_for_each_entry(file, &tr->events, list)
|
||||
if (file->event_call == &tp->call)
|
||||
return file;
|
||||
|
||||
return NULL;
|
||||
}
|
||||
|
||||
static __init int kprobe_trace_self_tests_init(void)
|
||||
{
|
||||
int ret, warn = 0;
|
||||
int (*target)(int, int, int, int, int, int);
|
||||
struct trace_probe *tp;
|
||||
struct ftrace_event_file *file;
|
||||
|
||||
target = kprobe_trace_selftest_target;
|
||||
|
||||
|
|
@ -1204,31 +1358,43 @@ static __init int kprobe_trace_self_tests_init(void)
|
|||
"$stack $stack0 +0($stack)",
|
||||
create_trace_probe);
|
||||
if (WARN_ON_ONCE(ret)) {
|
||||
pr_warning("error on probing function entry.\n");
|
||||
pr_warn("error on probing function entry.\n");
|
||||
warn++;
|
||||
} else {
|
||||
/* Enable trace point */
|
||||
tp = find_trace_probe("testprobe", KPROBE_EVENT_SYSTEM);
|
||||
if (WARN_ON_ONCE(tp == NULL)) {
|
||||
pr_warning("error on getting new probe.\n");
|
||||
pr_warn("error on getting new probe.\n");
|
||||
warn++;
|
||||
} else {
|
||||
file = find_trace_probe_file(tp, top_trace_array());
|
||||
if (WARN_ON_ONCE(file == NULL)) {
|
||||
pr_warn("error on getting probe file.\n");
|
||||
warn++;
|
||||
} else
|
||||
enable_trace_probe(tp, TP_FLAG_TRACE);
|
||||
enable_trace_probe(tp, file);
|
||||
}
|
||||
}
|
||||
|
||||
ret = traceprobe_command("r:testprobe2 kprobe_trace_selftest_target "
|
||||
"$retval", create_trace_probe);
|
||||
if (WARN_ON_ONCE(ret)) {
|
||||
pr_warning("error on probing function return.\n");
|
||||
pr_warn("error on probing function return.\n");
|
||||
warn++;
|
||||
} else {
|
||||
/* Enable trace point */
|
||||
tp = find_trace_probe("testprobe2", KPROBE_EVENT_SYSTEM);
|
||||
if (WARN_ON_ONCE(tp == NULL)) {
|
||||
pr_warning("error on getting new probe.\n");
|
||||
pr_warn("error on getting 2nd new probe.\n");
|
||||
warn++;
|
||||
} else {
|
||||
file = find_trace_probe_file(tp, top_trace_array());
|
||||
if (WARN_ON_ONCE(file == NULL)) {
|
||||
pr_warn("error on getting probe file.\n");
|
||||
warn++;
|
||||
} else
|
||||
enable_trace_probe(tp, TP_FLAG_TRACE);
|
||||
enable_trace_probe(tp, file);
|
||||
}
|
||||
}
|
||||
|
||||
if (warn)
|
||||
|
|
@ -1239,27 +1405,39 @@ static __init int kprobe_trace_self_tests_init(void)
|
|||
/* Disable trace points before removing it */
|
||||
tp = find_trace_probe("testprobe", KPROBE_EVENT_SYSTEM);
|
||||
if (WARN_ON_ONCE(tp == NULL)) {
|
||||
pr_warning("error on getting test probe.\n");
|
||||
pr_warn("error on getting test probe.\n");
|
||||
warn++;
|
||||
} else {
|
||||
file = find_trace_probe_file(tp, top_trace_array());
|
||||
if (WARN_ON_ONCE(file == NULL)) {
|
||||
pr_warn("error on getting probe file.\n");
|
||||
warn++;
|
||||
} else
|
||||
disable_trace_probe(tp, TP_FLAG_TRACE);
|
||||
disable_trace_probe(tp, file);
|
||||
}
|
||||
|
||||
tp = find_trace_probe("testprobe2", KPROBE_EVENT_SYSTEM);
|
||||
if (WARN_ON_ONCE(tp == NULL)) {
|
||||
pr_warning("error on getting 2nd test probe.\n");
|
||||
pr_warn("error on getting 2nd test probe.\n");
|
||||
warn++;
|
||||
} else {
|
||||
file = find_trace_probe_file(tp, top_trace_array());
|
||||
if (WARN_ON_ONCE(file == NULL)) {
|
||||
pr_warn("error on getting probe file.\n");
|
||||
warn++;
|
||||
} else
|
||||
disable_trace_probe(tp, TP_FLAG_TRACE);
|
||||
disable_trace_probe(tp, file);
|
||||
}
|
||||
|
||||
ret = traceprobe_command("-:testprobe", create_trace_probe);
|
||||
if (WARN_ON_ONCE(ret)) {
|
||||
pr_warning("error on deleting a probe.\n");
|
||||
pr_warn("error on deleting a probe.\n");
|
||||
warn++;
|
||||
}
|
||||
|
||||
ret = traceprobe_command("-:testprobe2", create_trace_probe);
|
||||
if (WARN_ON_ONCE(ret)) {
|
||||
pr_warning("error on deleting a probe.\n");
|
||||
pr_warn("error on deleting a probe.\n");
|
||||
warn++;
|
||||
}
|
||||
|
||||
|
|
|
|||
Loading…
Reference in New Issue