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tracing/probe: Split trace_event related data from trace_probe
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Split the trace_event related data from trace_probe data structure
and introduce trace_probe_event data structure for its folder.
This trace_probe_event data structure can have multiple trace_probe.

Link: http://lkml.kernel.org/r/156095683995.28024.7552150340561557873.stgit@devnote2

Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
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Masami Hiramatsu authored and Steven Rostedt (VMware) committed Aug 31, 2019
1 parent 17e262e commit 60d53e2
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Showing 4 changed files with 311 additions and 113 deletions.
157 changes: 115 additions & 42 deletions kernel/trace/trace_kprobe.c
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Original file line number Diff line number Diff line change
Expand Up @@ -180,20 +180,33 @@ unsigned long trace_kprobe_address(struct trace_kprobe *tk)
return addr;
}

static nokprobe_inline struct trace_kprobe *
trace_kprobe_primary_from_call(struct trace_event_call *call)
{
struct trace_probe *tp;

tp = trace_probe_primary_from_call(call);
if (WARN_ON_ONCE(!tp))
return NULL;

return container_of(tp, struct trace_kprobe, tp);
}

bool trace_kprobe_on_func_entry(struct trace_event_call *call)
{
struct trace_kprobe *tk = (struct trace_kprobe *)call->data;
struct trace_kprobe *tk = trace_kprobe_primary_from_call(call);

return kprobe_on_func_entry(tk->rp.kp.addr,
return tk ? kprobe_on_func_entry(tk->rp.kp.addr,
tk->rp.kp.addr ? NULL : tk->rp.kp.symbol_name,
tk->rp.kp.addr ? 0 : tk->rp.kp.offset);
tk->rp.kp.addr ? 0 : tk->rp.kp.offset) : false;
}

bool trace_kprobe_error_injectable(struct trace_event_call *call)
{
struct trace_kprobe *tk = (struct trace_kprobe *)call->data;
struct trace_kprobe *tk = trace_kprobe_primary_from_call(call);

return within_error_injection_list(trace_kprobe_address(tk));
return tk ? within_error_injection_list(trace_kprobe_address(tk)) :
false;
}

static int register_kprobe_event(struct trace_kprobe *tk);
Expand Down Expand Up @@ -291,32 +304,75 @@ static inline int __enable_trace_kprobe(struct trace_kprobe *tk)
return ret;
}

static void __disable_trace_kprobe(struct trace_probe *tp)
{
struct trace_probe *pos;
struct trace_kprobe *tk;

list_for_each_entry(pos, trace_probe_probe_list(tp), list) {
tk = container_of(pos, struct trace_kprobe, tp);
if (!trace_kprobe_is_registered(tk))
continue;
if (trace_kprobe_is_return(tk))
disable_kretprobe(&tk->rp);
else
disable_kprobe(&tk->rp.kp);
}
}

/*
* Enable trace_probe
* if the file is NULL, enable "perf" handler, or enable "trace" handler.
*/
static int
enable_trace_kprobe(struct trace_kprobe *tk, struct trace_event_file *file)
static int enable_trace_kprobe(struct trace_event_call *call,
struct trace_event_file *file)
{
bool enabled = trace_probe_is_enabled(&tk->tp);
struct trace_probe *pos, *tp;
struct trace_kprobe *tk;
bool enabled;
int ret = 0;

tp = trace_probe_primary_from_call(call);
if (WARN_ON_ONCE(!tp))
return -ENODEV;
enabled = trace_probe_is_enabled(tp);

/* This also changes "enabled" state */
if (file) {
ret = trace_probe_add_file(&tk->tp, file);
ret = trace_probe_add_file(tp, file);
if (ret)
return ret;
} else
trace_probe_set_flag(&tk->tp, TP_FLAG_PROFILE);
trace_probe_set_flag(tp, TP_FLAG_PROFILE);

if (enabled)
return 0;

ret = __enable_trace_kprobe(tk);
if (ret) {
enabled = false;
list_for_each_entry(pos, trace_probe_probe_list(tp), list) {
tk = container_of(pos, struct trace_kprobe, tp);
if (trace_kprobe_has_gone(tk))
continue;
ret = __enable_trace_kprobe(tk);
if (ret) {
if (enabled) {
__disable_trace_kprobe(tp);
enabled = false;
}
break;
}
enabled = true;
}

if (!enabled) {
/* No probe is enabled. Roll back */
if (file)
trace_probe_remove_file(&tk->tp, file);
trace_probe_remove_file(tp, file);
else
trace_probe_clear_flag(&tk->tp, TP_FLAG_PROFILE);
trace_probe_clear_flag(tp, TP_FLAG_PROFILE);
if (!ret)
/* Since all probes are gone, this is not available */
ret = -EADDRNOTAVAIL;
}

return ret;
Expand All @@ -326,11 +382,14 @@ enable_trace_kprobe(struct trace_kprobe *tk, struct trace_event_file *file)
* Disable trace_probe
* if the file is NULL, disable "perf" handler, or disable "trace" handler.
*/
static int
disable_trace_kprobe(struct trace_kprobe *tk, struct trace_event_file *file)
static int disable_trace_kprobe(struct trace_event_call *call,
struct trace_event_file *file)
{
struct trace_probe *tp = &tk->tp;
int ret = 0;
struct trace_probe *tp;

tp = trace_probe_primary_from_call(call);
if (WARN_ON_ONCE(!tp))
return -ENODEV;

if (file) {
if (!trace_probe_get_file_link(tp, file))
Expand All @@ -341,12 +400,8 @@ disable_trace_kprobe(struct trace_kprobe *tk, struct trace_event_file *file)
} else
trace_probe_clear_flag(tp, TP_FLAG_PROFILE);

if (!trace_probe_is_enabled(tp) && trace_kprobe_is_registered(tk)) {
if (trace_kprobe_is_return(tk))
disable_kretprobe(&tk->rp);
else
disable_kprobe(&tk->rp.kp);
}
if (!trace_probe_is_enabled(tp))
__disable_trace_kprobe(tp);

out:
if (file)
Expand All @@ -358,7 +413,7 @@ disable_trace_kprobe(struct trace_kprobe *tk, struct trace_event_file *file)
*/
trace_probe_remove_file(tp, file);

return ret;
return 0;
}

#if defined(CONFIG_KPROBES_ON_FTRACE) && \
Expand Down Expand Up @@ -1089,7 +1144,10 @@ print_kprobe_event(struct trace_iterator *iter, int flags,
struct trace_probe *tp;

field = (struct kprobe_trace_entry_head *)iter->ent;
tp = container_of(event, struct trace_probe, call.event);
tp = trace_probe_primary_from_call(
container_of(event, struct trace_event_call, event));
if (WARN_ON_ONCE(!tp))
goto out;

trace_seq_printf(s, "%s: (", trace_probe_name(tp));

Expand All @@ -1116,7 +1174,10 @@ print_kretprobe_event(struct trace_iterator *iter, int flags,
struct trace_probe *tp;

field = (struct kretprobe_trace_entry_head *)iter->ent;
tp = container_of(event, struct trace_probe, call.event);
tp = trace_probe_primary_from_call(
container_of(event, struct trace_event_call, event));
if (WARN_ON_ONCE(!tp))
goto out;

trace_seq_printf(s, "%s: (", trace_probe_name(tp));

Expand Down Expand Up @@ -1145,23 +1206,31 @@ static int kprobe_event_define_fields(struct trace_event_call *event_call)
{
int ret;
struct kprobe_trace_entry_head field;
struct trace_kprobe *tk = (struct trace_kprobe *)event_call->data;
struct trace_probe *tp;

tp = trace_probe_primary_from_call(event_call);
if (WARN_ON_ONCE(!tp))
return -ENOENT;

DEFINE_FIELD(unsigned long, ip, FIELD_STRING_IP, 0);

return traceprobe_define_arg_fields(event_call, sizeof(field), &tk->tp);
return traceprobe_define_arg_fields(event_call, sizeof(field), tp);
}

static int kretprobe_event_define_fields(struct trace_event_call *event_call)
{
int ret;
struct kretprobe_trace_entry_head field;
struct trace_kprobe *tk = (struct trace_kprobe *)event_call->data;
struct trace_probe *tp;

tp = trace_probe_primary_from_call(event_call);
if (WARN_ON_ONCE(!tp))
return -ENOENT;

DEFINE_FIELD(unsigned long, func, FIELD_STRING_FUNC, 0);
DEFINE_FIELD(unsigned long, ret_ip, FIELD_STRING_RETIP, 0);

return traceprobe_define_arg_fields(event_call, sizeof(field), &tk->tp);
return traceprobe_define_arg_fields(event_call, sizeof(field), tp);
}

#ifdef CONFIG_PERF_EVENTS
Expand Down Expand Up @@ -1289,20 +1358,19 @@ int bpf_get_kprobe_info(const struct perf_event *event, u32 *fd_type,
static int kprobe_register(struct trace_event_call *event,
enum trace_reg type, void *data)
{
struct trace_kprobe *tk = (struct trace_kprobe *)event->data;
struct trace_event_file *file = data;

switch (type) {
case TRACE_REG_REGISTER:
return enable_trace_kprobe(tk, file);
return enable_trace_kprobe(event, file);
case TRACE_REG_UNREGISTER:
return disable_trace_kprobe(tk, file);
return disable_trace_kprobe(event, file);

#ifdef CONFIG_PERF_EVENTS
case TRACE_REG_PERF_REGISTER:
return enable_trace_kprobe(tk, NULL);
return enable_trace_kprobe(event, NULL);
case TRACE_REG_PERF_UNREGISTER:
return disable_trace_kprobe(tk, NULL);
return disable_trace_kprobe(event, NULL);
case TRACE_REG_PERF_OPEN:
case TRACE_REG_PERF_CLOSE:
case TRACE_REG_PERF_ADD:
Expand Down Expand Up @@ -1369,7 +1437,6 @@ static inline void init_trace_event_call(struct trace_kprobe *tk)

call->flags = TRACE_EVENT_FL_KPROBE;
call->class->reg = kprobe_register;
call->data = tk;
}

static int register_kprobe_event(struct trace_kprobe *tk)
Expand Down Expand Up @@ -1432,7 +1499,9 @@ void destroy_local_trace_kprobe(struct trace_event_call *event_call)
{
struct trace_kprobe *tk;

tk = container_of(event_call, struct trace_kprobe, tp.call);
tk = trace_kprobe_primary_from_call(event_call);
if (unlikely(!tk))
return;

if (trace_probe_is_enabled(&tk->tp)) {
WARN_ON(1);
Expand Down Expand Up @@ -1577,7 +1646,8 @@ static __init int kprobe_trace_self_tests_init(void)
pr_warn("error on getting probe file.\n");
warn++;
} else
enable_trace_kprobe(tk, file);
enable_trace_kprobe(
trace_probe_event_call(&tk->tp), file);
}
}

Expand All @@ -1598,7 +1668,8 @@ static __init int kprobe_trace_self_tests_init(void)
pr_warn("error on getting probe file.\n");
warn++;
} else
enable_trace_kprobe(tk, file);
enable_trace_kprobe(
trace_probe_event_call(&tk->tp), file);
}
}

Expand Down Expand Up @@ -1631,7 +1702,8 @@ static __init int kprobe_trace_self_tests_init(void)
pr_warn("error on getting probe file.\n");
warn++;
} else
disable_trace_kprobe(tk, file);
disable_trace_kprobe(
trace_probe_event_call(&tk->tp), file);
}

tk = find_trace_kprobe("testprobe2", KPROBE_EVENT_SYSTEM);
Expand All @@ -1649,7 +1721,8 @@ static __init int kprobe_trace_self_tests_init(void)
pr_warn("error on getting probe file.\n");
warn++;
} else
disable_trace_kprobe(tk, file);
disable_trace_kprobe(
trace_probe_event_call(&tk->tp), file);
}

ret = trace_run_command("-:testprobe", create_or_delete_trace_kprobe);
Expand Down
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