Messages in this thread Patch in this message | | | From | Divya Indi <> | Subject | [PATCH 3/3] tracing: Add 2 new funcs. for kernel access to Ftrace instances. | Date | Tue, 4 Jun 2019 17:42:05 -0700 |
| |
Adding 2 new functions - 1) trace_array_lookup : Look up and return a trace array, given its name. 2) trace_array_set_clr_event : Enable/disable event recording to the given trace array.
Signed-off-by: Divya Indi <divya.indi@oracle.com> --- include/linux/trace_events.h | 3 +++ kernel/trace/trace.c | 11 +++++++++++ kernel/trace/trace_events.c | 22 ++++++++++++++++++++++ 3 files changed, 36 insertions(+)
diff --git a/include/linux/trace_events.h b/include/linux/trace_events.h index d7b7d85..0cc99a8 100644 --- a/include/linux/trace_events.h +++ b/include/linux/trace_events.h @@ -545,7 +545,10 @@ int trace_array_printk(struct trace_array *tr, unsigned long ip, struct trace_array *trace_array_create(const char *name); int trace_array_destroy(struct trace_array *tr); int ftrace_set_clr_event(struct trace_array *tr, char *buf, int set); +struct trace_array *trace_array_lookup(const char *name); int trace_set_clr_event(const char *system, const char *event, int set); +int trace_array_set_clr_event(struct trace_array *tr, const char *system, + const char *event, int set); /* * The double __builtin_constant_p is because gcc will give us an error diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index a60dc13..1d171fd 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -8465,6 +8465,17 @@ static int instance_rmdir(const char *name) return ret; } +struct trace_array *trace_array_lookup(const char *name) +{ + struct trace_array *tr; + list_for_each_entry(tr, &ftrace_trace_arrays, list) { + if (tr->name && strcmp(tr->name, name) == 0) + return tr; + } + return NULL; +} +EXPORT_SYMBOL_GPL(trace_array_lookup); + static __init void create_trace_instances(struct dentry *d_tracer) { trace_instance_dir = tracefs_create_instance_dir("instances", d_tracer, diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c index 445b059..c126d2c 100644 --- a/kernel/trace/trace_events.c +++ b/kernel/trace/trace_events.c @@ -859,6 +859,28 @@ int trace_set_clr_event(const char *system, const char *event, int set) } EXPORT_SYMBOL_GPL(trace_set_clr_event); +/** + * trace_array_set_clr_event - enable or disable an event for a trace array + * @system: system name to match (NULL for any system) + * @event: event name to match (NULL for all events, within system) + * @set: 1 to enable, 0 to disable + * + * This is a way for other parts of the kernel to enable or disable + * event recording to instances. + * + * Returns 0 on success, -EINVAL if the parameters do not match any + * registered events. + */ +int trace_array_set_clr_event(struct trace_array *tr, const char *system, + const char *event, int set) +{ + if (!tr) + return -ENODEV; + + return __ftrace_set_clr_event(tr, NULL, system, event, set); +} +EXPORT_SYMBOL_GPL(trace_array_set_clr_event); + /* 128 should be much more than enough */ #define EVENT_BUF_SIZE 127 -- 1.8.3.1
| |