1043 lines
24 KiB
Diff
1043 lines
24 KiB
Diff
From: Tom Zanussi <tom.zanussi@linux.intel.com>
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Date: Mon, 15 Jan 2018 20:51:58 -0600
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Subject: [PATCH 32/48] tracing: Add support for 'synthetic' events
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Origin: https://www.kernel.org/pub/linux/kernel/projects/rt/4.16/older/patches-4.16.7-rt1.tar.xz
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Synthetic events are user-defined events generated from hist trigger
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variables saved from one or more other events.
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To define a synthetic event, the user writes a simple specification
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consisting of the name of the new event along with one or more
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variables and their type(s), to the tracing/synthetic_events file.
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For instance, the following creates a new event named 'wakeup_latency'
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with 3 fields: lat, pid, and prio:
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# echo 'wakeup_latency u64 lat; pid_t pid; int prio' >> \
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/sys/kernel/debug/tracing/synthetic_events
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Reading the tracing/synthetic_events file lists all the
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currently-defined synthetic events, in this case the event we defined
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above:
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# cat /sys/kernel/debug/tracing/synthetic_events
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wakeup_latency u64 lat; pid_t pid; int prio
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At this point, the synthetic event is ready to use, and a histogram
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can be defined using it:
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# echo 'hist:keys=pid,prio,lat.log2:sort=pid,lat' >> \
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/sys/kernel/debug/tracing/events/synthetic/wakeup_latency/trigger
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The new event is created under the tracing/events/synthetic/ directory
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and looks and behaves just like any other event:
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# ls /sys/kernel/debug/tracing/events/synthetic/wakeup_latency
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enable filter format hist id trigger
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Although a histogram can be defined for it, nothing will happen until
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an action tracing that event via the trace_synth() function occurs.
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The trace_synth() function is very similar to all the other trace_*
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invocations spread throughout the kernel, except in this case the
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trace_ function and its corresponding tracepoint isn't statically
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generated but defined by the user at run-time.
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How this can be automatically hooked up via a hist trigger 'action' is
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discussed in a subsequent patch.
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Link: http://lkml.kernel.org/r/c68df2284b7d172669daf9be29db62ad49bbc559.1516069914.git.tom.zanussi@linux.intel.com
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Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
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[fix noderef.cocci warnings, sizeof pointer for kcalloc of event->fields]
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Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
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Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
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(cherry picked from commit cc9371f8641efd7ce6c8d4e1fd44eae249deadb4)
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Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
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---
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kernel/trace/trace_events_hist.c | 895 ++++++++++++++++++++++++++++++++++++++-
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1 file changed, 893 insertions(+), 2 deletions(-)
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--- a/kernel/trace/trace_events_hist.c
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+++ b/kernel/trace/trace_events_hist.c
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@@ -20,10 +20,16 @@
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#include <linux/slab.h>
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#include <linux/stacktrace.h>
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#include <linux/rculist.h>
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+#include <linux/tracefs.h>
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#include "tracing_map.h"
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#include "trace.h"
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+#define SYNTH_SYSTEM "synthetic"
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+#define SYNTH_FIELDS_MAX 16
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+
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+#define STR_VAR_LEN_MAX 32 /* must be multiple of sizeof(u64) */
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+
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struct hist_field;
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typedef u64 (*hist_field_fn_t) (struct hist_field *field,
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@@ -270,6 +276,26 @@ struct hist_trigger_data {
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unsigned int n_actions;
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};
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+struct synth_field {
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+ char *type;
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+ char *name;
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+ size_t size;
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+ bool is_signed;
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+ bool is_string;
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+};
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+
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+struct synth_event {
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+ struct list_head list;
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+ int ref;
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+ char *name;
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+ struct synth_field **fields;
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+ unsigned int n_fields;
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+ unsigned int n_u64;
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+ struct trace_event_class class;
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+ struct trace_event_call call;
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+ struct tracepoint *tp;
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+};
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+
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struct action_data;
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typedef void (*action_fn_t) (struct hist_trigger_data *hist_data,
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@@ -282,6 +308,790 @@ struct action_data {
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unsigned int var_ref_idx;
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};
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+static LIST_HEAD(synth_event_list);
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+static DEFINE_MUTEX(synth_event_mutex);
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+
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+struct synth_trace_event {
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+ struct trace_entry ent;
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+ u64 fields[];
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+};
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+
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+static int synth_event_define_fields(struct trace_event_call *call)
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+{
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+ struct synth_trace_event trace;
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+ int offset = offsetof(typeof(trace), fields);
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+ struct synth_event *event = call->data;
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+ unsigned int i, size, n_u64;
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+ char *name, *type;
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+ bool is_signed;
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+ int ret = 0;
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+
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+ for (i = 0, n_u64 = 0; i < event->n_fields; i++) {
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+ size = event->fields[i]->size;
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+ is_signed = event->fields[i]->is_signed;
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+ type = event->fields[i]->type;
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+ name = event->fields[i]->name;
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+ ret = trace_define_field(call, type, name, offset, size,
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+ is_signed, FILTER_OTHER);
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+ if (ret)
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+ break;
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+
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+ if (event->fields[i]->is_string) {
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+ offset += STR_VAR_LEN_MAX;
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+ n_u64 += STR_VAR_LEN_MAX / sizeof(u64);
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+ } else {
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+ offset += sizeof(u64);
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+ n_u64++;
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+ }
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+ }
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+
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+ event->n_u64 = n_u64;
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+
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+ return ret;
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+}
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+
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+static bool synth_field_signed(char *type)
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+{
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+ if (strncmp(type, "u", 1) == 0)
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+ return false;
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+
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+ return true;
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+}
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+
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+static int synth_field_is_string(char *type)
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+{
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+ if (strstr(type, "char[") != NULL)
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+ return true;
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+
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+ return false;
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+}
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+
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+static int synth_field_string_size(char *type)
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+{
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+ char buf[4], *end, *start;
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+ unsigned int len;
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+ int size, err;
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+
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+ start = strstr(type, "char[");
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+ if (start == NULL)
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+ return -EINVAL;
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+ start += strlen("char[");
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+
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+ end = strchr(type, ']');
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+ if (!end || end < start)
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+ return -EINVAL;
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+
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+ len = end - start;
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+ if (len > 3)
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+ return -EINVAL;
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+
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+ strncpy(buf, start, len);
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+ buf[len] = '\0';
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+
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+ err = kstrtouint(buf, 0, &size);
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+ if (err)
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+ return err;
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+
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+ if (size > STR_VAR_LEN_MAX)
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+ return -EINVAL;
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+
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+ return size;
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+}
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+
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+static int synth_field_size(char *type)
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+{
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+ int size = 0;
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+
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+ if (strcmp(type, "s64") == 0)
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+ size = sizeof(s64);
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+ else if (strcmp(type, "u64") == 0)
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+ size = sizeof(u64);
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+ else if (strcmp(type, "s32") == 0)
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+ size = sizeof(s32);
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+ else if (strcmp(type, "u32") == 0)
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+ size = sizeof(u32);
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+ else if (strcmp(type, "s16") == 0)
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+ size = sizeof(s16);
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+ else if (strcmp(type, "u16") == 0)
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+ size = sizeof(u16);
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+ else if (strcmp(type, "s8") == 0)
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+ size = sizeof(s8);
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+ else if (strcmp(type, "u8") == 0)
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+ size = sizeof(u8);
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+ else if (strcmp(type, "char") == 0)
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+ size = sizeof(char);
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+ else if (strcmp(type, "unsigned char") == 0)
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+ size = sizeof(unsigned char);
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+ else if (strcmp(type, "int") == 0)
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+ size = sizeof(int);
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+ else if (strcmp(type, "unsigned int") == 0)
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+ size = sizeof(unsigned int);
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+ else if (strcmp(type, "long") == 0)
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+ size = sizeof(long);
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+ else if (strcmp(type, "unsigned long") == 0)
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+ size = sizeof(unsigned long);
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+ else if (strcmp(type, "pid_t") == 0)
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+ size = sizeof(pid_t);
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+ else if (synth_field_is_string(type))
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+ size = synth_field_string_size(type);
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+
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+ return size;
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+}
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+
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+static const char *synth_field_fmt(char *type)
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+{
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+ const char *fmt = "%llu";
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+
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+ if (strcmp(type, "s64") == 0)
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+ fmt = "%lld";
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+ else if (strcmp(type, "u64") == 0)
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+ fmt = "%llu";
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+ else if (strcmp(type, "s32") == 0)
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+ fmt = "%d";
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+ else if (strcmp(type, "u32") == 0)
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+ fmt = "%u";
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+ else if (strcmp(type, "s16") == 0)
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+ fmt = "%d";
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+ else if (strcmp(type, "u16") == 0)
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+ fmt = "%u";
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+ else if (strcmp(type, "s8") == 0)
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+ fmt = "%d";
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+ else if (strcmp(type, "u8") == 0)
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+ fmt = "%u";
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+ else if (strcmp(type, "char") == 0)
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+ fmt = "%d";
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+ else if (strcmp(type, "unsigned char") == 0)
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+ fmt = "%u";
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+ else if (strcmp(type, "int") == 0)
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+ fmt = "%d";
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+ else if (strcmp(type, "unsigned int") == 0)
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+ fmt = "%u";
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+ else if (strcmp(type, "long") == 0)
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+ fmt = "%ld";
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+ else if (strcmp(type, "unsigned long") == 0)
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+ fmt = "%lu";
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+ else if (strcmp(type, "pid_t") == 0)
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+ fmt = "%d";
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+ else if (synth_field_is_string(type))
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+ fmt = "%s";
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+
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+ return fmt;
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+}
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+
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+static enum print_line_t print_synth_event(struct trace_iterator *iter,
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+ int flags,
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+ struct trace_event *event)
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+{
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+ struct trace_array *tr = iter->tr;
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+ struct trace_seq *s = &iter->seq;
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+ struct synth_trace_event *entry;
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+ struct synth_event *se;
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+ unsigned int i, n_u64;
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+ char print_fmt[32];
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+ const char *fmt;
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+
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+ entry = (struct synth_trace_event *)iter->ent;
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+ se = container_of(event, struct synth_event, call.event);
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+
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+ trace_seq_printf(s, "%s: ", se->name);
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+
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+ for (i = 0, n_u64 = 0; i < se->n_fields; i++) {
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+ if (trace_seq_has_overflowed(s))
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+ goto end;
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+
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+ fmt = synth_field_fmt(se->fields[i]->type);
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+
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+ /* parameter types */
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+ if (tr->trace_flags & TRACE_ITER_VERBOSE)
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+ trace_seq_printf(s, "%s ", fmt);
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+
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+ snprintf(print_fmt, sizeof(print_fmt), "%%s=%s%%s", fmt);
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+
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+ /* parameter values */
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+ if (se->fields[i]->is_string) {
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+ trace_seq_printf(s, print_fmt, se->fields[i]->name,
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+ (char *)&entry->fields[n_u64],
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+ i == se->n_fields - 1 ? "" : " ");
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+ n_u64 += STR_VAR_LEN_MAX / sizeof(u64);
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+ } else {
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+ trace_seq_printf(s, print_fmt, se->fields[i]->name,
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+ entry->fields[n_u64],
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+ i == se->n_fields - 1 ? "" : " ");
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+ n_u64++;
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+ }
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+ }
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+end:
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+ trace_seq_putc(s, '\n');
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+
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+ return trace_handle_return(s);
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+}
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+
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+static struct trace_event_functions synth_event_funcs = {
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+ .trace = print_synth_event
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+};
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+
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+static notrace void trace_event_raw_event_synth(void *__data,
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+ u64 *var_ref_vals,
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+ unsigned int var_ref_idx)
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+{
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+ struct trace_event_file *trace_file = __data;
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+ struct synth_trace_event *entry;
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+ struct trace_event_buffer fbuffer;
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+ struct synth_event *event;
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+ unsigned int i, n_u64;
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+ int fields_size = 0;
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+
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+ event = trace_file->event_call->data;
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+
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+ if (trace_trigger_soft_disabled(trace_file))
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+ return;
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+
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+ fields_size = event->n_u64 * sizeof(u64);
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+
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+ entry = trace_event_buffer_reserve(&fbuffer, trace_file,
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+ sizeof(*entry) + fields_size);
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+ if (!entry)
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+ return;
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+
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+ for (i = 0, n_u64 = 0; i < event->n_fields; i++) {
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+ if (event->fields[i]->is_string) {
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+ char *str_val = (char *)(long)var_ref_vals[var_ref_idx + i];
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+ char *str_field = (char *)&entry->fields[n_u64];
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+
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+ strncpy(str_field, str_val, STR_VAR_LEN_MAX);
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+ n_u64 += STR_VAR_LEN_MAX / sizeof(u64);
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+ } else {
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+ entry->fields[n_u64] = var_ref_vals[var_ref_idx + i];
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+ n_u64++;
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+ }
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+ }
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+
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+ trace_event_buffer_commit(&fbuffer);
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+}
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+
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+static void free_synth_event_print_fmt(struct trace_event_call *call)
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+{
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+ if (call) {
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+ kfree(call->print_fmt);
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+ call->print_fmt = NULL;
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+ }
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+}
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+
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+static int __set_synth_event_print_fmt(struct synth_event *event,
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+ char *buf, int len)
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+{
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+ const char *fmt;
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+ int pos = 0;
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+ int i;
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+
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+ /* When len=0, we just calculate the needed length */
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+#define LEN_OR_ZERO (len ? len - pos : 0)
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+
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+ pos += snprintf(buf + pos, LEN_OR_ZERO, "\"");
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+ for (i = 0; i < event->n_fields; i++) {
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+ fmt = synth_field_fmt(event->fields[i]->type);
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+ pos += snprintf(buf + pos, LEN_OR_ZERO, "%s=%s%s",
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+ event->fields[i]->name, fmt,
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+ i == event->n_fields - 1 ? "" : ", ");
|
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+ }
|
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+ pos += snprintf(buf + pos, LEN_OR_ZERO, "\"");
|
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+
|
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+ for (i = 0; i < event->n_fields; i++) {
|
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+ pos += snprintf(buf + pos, LEN_OR_ZERO,
|
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+ ", REC->%s", event->fields[i]->name);
|
|
+ }
|
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+
|
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+#undef LEN_OR_ZERO
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+
|
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+ /* return the length of print_fmt */
|
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+ return pos;
|
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+}
|
|
+
|
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+static int set_synth_event_print_fmt(struct trace_event_call *call)
|
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+{
|
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+ struct synth_event *event = call->data;
|
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+ char *print_fmt;
|
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+ int len;
|
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+
|
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+ /* First: called with 0 length to calculate the needed length */
|
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+ len = __set_synth_event_print_fmt(event, NULL, 0);
|
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+
|
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+ print_fmt = kmalloc(len + 1, GFP_KERNEL);
|
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+ if (!print_fmt)
|
|
+ return -ENOMEM;
|
|
+
|
|
+ /* Second: actually write the @print_fmt */
|
|
+ __set_synth_event_print_fmt(event, print_fmt, len + 1);
|
|
+ call->print_fmt = print_fmt;
|
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+
|
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+ return 0;
|
|
+}
|
|
+
|
|
+static void free_synth_field(struct synth_field *field)
|
|
+{
|
|
+ kfree(field->type);
|
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+ kfree(field->name);
|
|
+ kfree(field);
|
|
+}
|
|
+
|
|
+static struct synth_field *parse_synth_field(char *field_type,
|
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+ char *field_name)
|
|
+{
|
|
+ struct synth_field *field;
|
|
+ int len, ret = 0;
|
|
+ char *array;
|
|
+
|
|
+ if (field_type[0] == ';')
|
|
+ field_type++;
|
|
+
|
|
+ len = strlen(field_name);
|
|
+ if (field_name[len - 1] == ';')
|
|
+ field_name[len - 1] = '\0';
|
|
+
|
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+ field = kzalloc(sizeof(*field), GFP_KERNEL);
|
|
+ if (!field)
|
|
+ return ERR_PTR(-ENOMEM);
|
|
+
|
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+ len = strlen(field_type) + 1;
|
|
+ array = strchr(field_name, '[');
|
|
+ if (array)
|
|
+ len += strlen(array);
|
|
+ field->type = kzalloc(len, GFP_KERNEL);
|
|
+ if (!field->type) {
|
|
+ ret = -ENOMEM;
|
|
+ goto free;
|
|
+ }
|
|
+ strcat(field->type, field_type);
|
|
+ if (array) {
|
|
+ strcat(field->type, array);
|
|
+ *array = '\0';
|
|
+ }
|
|
+
|
|
+ field->size = synth_field_size(field->type);
|
|
+ if (!field->size) {
|
|
+ ret = -EINVAL;
|
|
+ goto free;
|
|
+ }
|
|
+
|
|
+ if (synth_field_is_string(field->type))
|
|
+ field->is_string = true;
|
|
+
|
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+ field->is_signed = synth_field_signed(field->type);
|
|
+
|
|
+ field->name = kstrdup(field_name, GFP_KERNEL);
|
|
+ if (!field->name) {
|
|
+ ret = -ENOMEM;
|
|
+ goto free;
|
|
+ }
|
|
+ out:
|
|
+ return field;
|
|
+ free:
|
|
+ free_synth_field(field);
|
|
+ field = ERR_PTR(ret);
|
|
+ goto out;
|
|
+}
|
|
+
|
|
+static void free_synth_tracepoint(struct tracepoint *tp)
|
|
+{
|
|
+ if (!tp)
|
|
+ return;
|
|
+
|
|
+ kfree(tp->name);
|
|
+ kfree(tp);
|
|
+}
|
|
+
|
|
+static struct tracepoint *alloc_synth_tracepoint(char *name)
|
|
+{
|
|
+ struct tracepoint *tp;
|
|
+
|
|
+ tp = kzalloc(sizeof(*tp), GFP_KERNEL);
|
|
+ if (!tp)
|
|
+ return ERR_PTR(-ENOMEM);
|
|
+
|
|
+ tp->name = kstrdup(name, GFP_KERNEL);
|
|
+ if (!tp->name) {
|
|
+ kfree(tp);
|
|
+ return ERR_PTR(-ENOMEM);
|
|
+ }
|
|
+
|
|
+ return tp;
|
|
+}
|
|
+
|
|
+typedef void (*synth_probe_func_t) (void *__data, u64 *var_ref_vals,
|
|
+ unsigned int var_ref_idx);
|
|
+
|
|
+static inline void trace_synth(struct synth_event *event, u64 *var_ref_vals,
|
|
+ unsigned int var_ref_idx)
|
|
+{
|
|
+ struct tracepoint *tp = event->tp;
|
|
+
|
|
+ if (unlikely(atomic_read(&tp->key.enabled) > 0)) {
|
|
+ struct tracepoint_func *probe_func_ptr;
|
|
+ synth_probe_func_t probe_func;
|
|
+ void *__data;
|
|
+
|
|
+ if (!(cpu_online(raw_smp_processor_id())))
|
|
+ return;
|
|
+
|
|
+ probe_func_ptr = rcu_dereference_sched((tp)->funcs);
|
|
+ if (probe_func_ptr) {
|
|
+ do {
|
|
+ probe_func = probe_func_ptr->func;
|
|
+ __data = probe_func_ptr->data;
|
|
+ probe_func(__data, var_ref_vals, var_ref_idx);
|
|
+ } while ((++probe_func_ptr)->func);
|
|
+ }
|
|
+ }
|
|
+}
|
|
+
|
|
+static struct synth_event *find_synth_event(const char *name)
|
|
+{
|
|
+ struct synth_event *event;
|
|
+
|
|
+ list_for_each_entry(event, &synth_event_list, list) {
|
|
+ if (strcmp(event->name, name) == 0)
|
|
+ return event;
|
|
+ }
|
|
+
|
|
+ return NULL;
|
|
+}
|
|
+
|
|
+static int register_synth_event(struct synth_event *event)
|
|
+{
|
|
+ struct trace_event_call *call = &event->call;
|
|
+ int ret = 0;
|
|
+
|
|
+ event->call.class = &event->class;
|
|
+ event->class.system = kstrdup(SYNTH_SYSTEM, GFP_KERNEL);
|
|
+ if (!event->class.system) {
|
|
+ ret = -ENOMEM;
|
|
+ goto out;
|
|
+ }
|
|
+
|
|
+ event->tp = alloc_synth_tracepoint(event->name);
|
|
+ if (IS_ERR(event->tp)) {
|
|
+ ret = PTR_ERR(event->tp);
|
|
+ event->tp = NULL;
|
|
+ goto out;
|
|
+ }
|
|
+
|
|
+ INIT_LIST_HEAD(&call->class->fields);
|
|
+ call->event.funcs = &synth_event_funcs;
|
|
+ call->class->define_fields = synth_event_define_fields;
|
|
+
|
|
+ ret = register_trace_event(&call->event);
|
|
+ if (!ret) {
|
|
+ ret = -ENODEV;
|
|
+ goto out;
|
|
+ }
|
|
+ call->flags = TRACE_EVENT_FL_TRACEPOINT;
|
|
+ call->class->reg = trace_event_reg;
|
|
+ call->class->probe = trace_event_raw_event_synth;
|
|
+ call->data = event;
|
|
+ call->tp = event->tp;
|
|
+
|
|
+ ret = trace_add_event_call(call);
|
|
+ if (ret) {
|
|
+ pr_warn("Failed to register synthetic event: %s\n",
|
|
+ trace_event_name(call));
|
|
+ goto err;
|
|
+ }
|
|
+
|
|
+ ret = set_synth_event_print_fmt(call);
|
|
+ if (ret < 0) {
|
|
+ trace_remove_event_call(call);
|
|
+ goto err;
|
|
+ }
|
|
+ out:
|
|
+ return ret;
|
|
+ err:
|
|
+ unregister_trace_event(&call->event);
|
|
+ goto out;
|
|
+}
|
|
+
|
|
+static int unregister_synth_event(struct synth_event *event)
|
|
+{
|
|
+ struct trace_event_call *call = &event->call;
|
|
+ int ret;
|
|
+
|
|
+ ret = trace_remove_event_call(call);
|
|
+
|
|
+ return ret;
|
|
+}
|
|
+
|
|
+static void free_synth_event(struct synth_event *event)
|
|
+{
|
|
+ unsigned int i;
|
|
+
|
|
+ if (!event)
|
|
+ return;
|
|
+
|
|
+ for (i = 0; i < event->n_fields; i++)
|
|
+ free_synth_field(event->fields[i]);
|
|
+
|
|
+ kfree(event->fields);
|
|
+ kfree(event->name);
|
|
+ kfree(event->class.system);
|
|
+ free_synth_tracepoint(event->tp);
|
|
+ free_synth_event_print_fmt(&event->call);
|
|
+ kfree(event);
|
|
+}
|
|
+
|
|
+static struct synth_event *alloc_synth_event(char *event_name, int n_fields,
|
|
+ struct synth_field **fields)
|
|
+{
|
|
+ struct synth_event *event;
|
|
+ unsigned int i;
|
|
+
|
|
+ event = kzalloc(sizeof(*event), GFP_KERNEL);
|
|
+ if (!event) {
|
|
+ event = ERR_PTR(-ENOMEM);
|
|
+ goto out;
|
|
+ }
|
|
+
|
|
+ event->name = kstrdup(event_name, GFP_KERNEL);
|
|
+ if (!event->name) {
|
|
+ kfree(event);
|
|
+ event = ERR_PTR(-ENOMEM);
|
|
+ goto out;
|
|
+ }
|
|
+
|
|
+ event->fields = kcalloc(n_fields, sizeof(*event->fields), GFP_KERNEL);
|
|
+ if (!event->fields) {
|
|
+ free_synth_event(event);
|
|
+ event = ERR_PTR(-ENOMEM);
|
|
+ goto out;
|
|
+ }
|
|
+
|
|
+ for (i = 0; i < n_fields; i++)
|
|
+ event->fields[i] = fields[i];
|
|
+
|
|
+ event->n_fields = n_fields;
|
|
+ out:
|
|
+ return event;
|
|
+}
|
|
+
|
|
+static void add_or_delete_synth_event(struct synth_event *event, int delete)
|
|
+{
|
|
+ if (delete)
|
|
+ free_synth_event(event);
|
|
+ else {
|
|
+ mutex_lock(&synth_event_mutex);
|
|
+ if (!find_synth_event(event->name))
|
|
+ list_add(&event->list, &synth_event_list);
|
|
+ else
|
|
+ free_synth_event(event);
|
|
+ mutex_unlock(&synth_event_mutex);
|
|
+ }
|
|
+}
|
|
+
|
|
+static int create_synth_event(int argc, char **argv)
|
|
+{
|
|
+ struct synth_field *field, *fields[SYNTH_FIELDS_MAX];
|
|
+ struct synth_event *event = NULL;
|
|
+ bool delete_event = false;
|
|
+ int i, n_fields = 0, ret = 0;
|
|
+ char *name;
|
|
+
|
|
+ mutex_lock(&synth_event_mutex);
|
|
+
|
|
+ /*
|
|
+ * Argument syntax:
|
|
+ * - Add synthetic event: <event_name> field[;field] ...
|
|
+ * - Remove synthetic event: !<event_name> field[;field] ...
|
|
+ * where 'field' = type field_name
|
|
+ */
|
|
+ if (argc < 1) {
|
|
+ ret = -EINVAL;
|
|
+ goto out;
|
|
+ }
|
|
+
|
|
+ name = argv[0];
|
|
+ if (name[0] == '!') {
|
|
+ delete_event = true;
|
|
+ name++;
|
|
+ }
|
|
+
|
|
+ event = find_synth_event(name);
|
|
+ if (event) {
|
|
+ if (delete_event) {
|
|
+ if (event->ref) {
|
|
+ event = NULL;
|
|
+ ret = -EBUSY;
|
|
+ goto out;
|
|
+ }
|
|
+ list_del(&event->list);
|
|
+ goto out;
|
|
+ }
|
|
+ event = NULL;
|
|
+ ret = -EEXIST;
|
|
+ goto out;
|
|
+ } else if (delete_event)
|
|
+ goto out;
|
|
+
|
|
+ if (argc < 2) {
|
|
+ ret = -EINVAL;
|
|
+ goto out;
|
|
+ }
|
|
+
|
|
+ for (i = 1; i < argc - 1; i++) {
|
|
+ if (strcmp(argv[i], ";") == 0)
|
|
+ continue;
|
|
+ if (n_fields == SYNTH_FIELDS_MAX) {
|
|
+ ret = -EINVAL;
|
|
+ goto err;
|
|
+ }
|
|
+
|
|
+ field = parse_synth_field(argv[i], argv[i + 1]);
|
|
+ if (IS_ERR(field)) {
|
|
+ ret = PTR_ERR(field);
|
|
+ goto err;
|
|
+ }
|
|
+ fields[n_fields] = field;
|
|
+ i++; n_fields++;
|
|
+ }
|
|
+
|
|
+ if (i < argc) {
|
|
+ ret = -EINVAL;
|
|
+ goto err;
|
|
+ }
|
|
+
|
|
+ event = alloc_synth_event(name, n_fields, fields);
|
|
+ if (IS_ERR(event)) {
|
|
+ ret = PTR_ERR(event);
|
|
+ event = NULL;
|
|
+ goto err;
|
|
+ }
|
|
+ out:
|
|
+ mutex_unlock(&synth_event_mutex);
|
|
+
|
|
+ if (event) {
|
|
+ if (delete_event) {
|
|
+ ret = unregister_synth_event(event);
|
|
+ add_or_delete_synth_event(event, !ret);
|
|
+ } else {
|
|
+ ret = register_synth_event(event);
|
|
+ add_or_delete_synth_event(event, ret);
|
|
+ }
|
|
+ }
|
|
+
|
|
+ return ret;
|
|
+ err:
|
|
+ mutex_unlock(&synth_event_mutex);
|
|
+
|
|
+ for (i = 0; i < n_fields; i++)
|
|
+ free_synth_field(fields[i]);
|
|
+ free_synth_event(event);
|
|
+
|
|
+ return ret;
|
|
+}
|
|
+
|
|
+static int release_all_synth_events(void)
|
|
+{
|
|
+ struct list_head release_events;
|
|
+ struct synth_event *event, *e;
|
|
+ int ret = 0;
|
|
+
|
|
+ INIT_LIST_HEAD(&release_events);
|
|
+
|
|
+ mutex_lock(&synth_event_mutex);
|
|
+
|
|
+ list_for_each_entry(event, &synth_event_list, list) {
|
|
+ if (event->ref) {
|
|
+ mutex_unlock(&synth_event_mutex);
|
|
+ return -EBUSY;
|
|
+ }
|
|
+ }
|
|
+
|
|
+ list_splice_init(&event->list, &release_events);
|
|
+
|
|
+ mutex_unlock(&synth_event_mutex);
|
|
+
|
|
+ list_for_each_entry_safe(event, e, &release_events, list) {
|
|
+ list_del(&event->list);
|
|
+
|
|
+ ret = unregister_synth_event(event);
|
|
+ add_or_delete_synth_event(event, !ret);
|
|
+ }
|
|
+
|
|
+ return ret;
|
|
+}
|
|
+
|
|
+
|
|
+static void *synth_events_seq_start(struct seq_file *m, loff_t *pos)
|
|
+{
|
|
+ mutex_lock(&synth_event_mutex);
|
|
+
|
|
+ return seq_list_start(&synth_event_list, *pos);
|
|
+}
|
|
+
|
|
+static void *synth_events_seq_next(struct seq_file *m, void *v, loff_t *pos)
|
|
+{
|
|
+ return seq_list_next(v, &synth_event_list, pos);
|
|
+}
|
|
+
|
|
+static void synth_events_seq_stop(struct seq_file *m, void *v)
|
|
+{
|
|
+ mutex_unlock(&synth_event_mutex);
|
|
+}
|
|
+
|
|
+static int synth_events_seq_show(struct seq_file *m, void *v)
|
|
+{
|
|
+ struct synth_field *field;
|
|
+ struct synth_event *event = v;
|
|
+ unsigned int i;
|
|
+
|
|
+ seq_printf(m, "%s\t", event->name);
|
|
+
|
|
+ for (i = 0; i < event->n_fields; i++) {
|
|
+ field = event->fields[i];
|
|
+
|
|
+ /* parameter values */
|
|
+ seq_printf(m, "%s %s%s", field->type, field->name,
|
|
+ i == event->n_fields - 1 ? "" : "; ");
|
|
+ }
|
|
+
|
|
+ seq_putc(m, '\n');
|
|
+
|
|
+ return 0;
|
|
+}
|
|
+
|
|
+static const struct seq_operations synth_events_seq_op = {
|
|
+ .start = synth_events_seq_start,
|
|
+ .next = synth_events_seq_next,
|
|
+ .stop = synth_events_seq_stop,
|
|
+ .show = synth_events_seq_show
|
|
+};
|
|
+
|
|
+static int synth_events_open(struct inode *inode, struct file *file)
|
|
+{
|
|
+ int ret;
|
|
+
|
|
+ if ((file->f_mode & FMODE_WRITE) && (file->f_flags & O_TRUNC)) {
|
|
+ ret = release_all_synth_events();
|
|
+ if (ret < 0)
|
|
+ return ret;
|
|
+ }
|
|
+
|
|
+ return seq_open(file, &synth_events_seq_op);
|
|
+}
|
|
+
|
|
+static ssize_t synth_events_write(struct file *file,
|
|
+ const char __user *buffer,
|
|
+ size_t count, loff_t *ppos)
|
|
+{
|
|
+ return trace_parse_run_command(file, buffer, count, ppos,
|
|
+ create_synth_event);
|
|
+}
|
|
+
|
|
+static const struct file_operations synth_events_fops = {
|
|
+ .open = synth_events_open,
|
|
+ .write = synth_events_write,
|
|
+ .read = seq_read,
|
|
+ .llseek = seq_lseek,
|
|
+ .release = seq_release,
|
|
+};
|
|
+
|
|
static u64 hist_field_timestamp(struct hist_field *hist_field,
|
|
struct tracing_map_elt *elt,
|
|
struct ring_buffer_event *rbe,
|
|
@@ -2963,6 +3773,28 @@ static int hist_trigger_enable(struct ev
|
|
return ret;
|
|
}
|
|
|
|
+static bool have_hist_trigger_match(struct event_trigger_data *data,
|
|
+ struct trace_event_file *file)
|
|
+{
|
|
+ struct hist_trigger_data *hist_data = data->private_data;
|
|
+ struct event_trigger_data *test, *named_data = NULL;
|
|
+ bool match = false;
|
|
+
|
|
+ if (hist_data->attrs->name)
|
|
+ named_data = find_named_trigger(hist_data->attrs->name);
|
|
+
|
|
+ list_for_each_entry_rcu(test, &file->triggers, list) {
|
|
+ if (test->cmd_ops->trigger_type == ETT_EVENT_HIST) {
|
|
+ if (hist_trigger_match(data, test, named_data, false)) {
|
|
+ match = true;
|
|
+ break;
|
|
+ }
|
|
+ }
|
|
+ }
|
|
+
|
|
+ return match;
|
|
+}
|
|
+
|
|
static bool hist_trigger_check_refs(struct event_trigger_data *data,
|
|
struct trace_event_file *file)
|
|
{
|
|
@@ -3038,6 +3870,8 @@ static void hist_unreg_all(struct trace_
|
|
{
|
|
struct event_trigger_data *test, *n;
|
|
struct hist_trigger_data *hist_data;
|
|
+ struct synth_event *se;
|
|
+ const char *se_name;
|
|
|
|
if (hist_file_check_refs(file))
|
|
return;
|
|
@@ -3047,6 +3881,14 @@ static void hist_unreg_all(struct trace_
|
|
hist_data = test->private_data;
|
|
list_del_rcu(&test->list);
|
|
trace_event_trigger_enable_disable(file, 0);
|
|
+
|
|
+ mutex_lock(&synth_event_mutex);
|
|
+ se_name = trace_event_name(file->event_call);
|
|
+ se = find_synth_event(se_name);
|
|
+ if (se)
|
|
+ se->ref--;
|
|
+ mutex_unlock(&synth_event_mutex);
|
|
+
|
|
update_cond_flag(file);
|
|
if (hist_data->enable_timestamps)
|
|
tracing_set_time_stamp_abs(file->tr, false);
|
|
@@ -3065,6 +3907,8 @@ static int event_hist_trigger_func(struc
|
|
struct hist_trigger_attrs *attrs;
|
|
struct event_trigger_ops *trigger_ops;
|
|
struct hist_trigger_data *hist_data;
|
|
+ struct synth_event *se;
|
|
+ const char *se_name;
|
|
bool remove = false;
|
|
char *trigger;
|
|
int ret = 0;
|
|
@@ -3095,10 +3939,11 @@ static int event_hist_trigger_func(struc
|
|
|
|
trigger_ops = cmd_ops->get_trigger_ops(cmd, trigger);
|
|
|
|
- ret = -ENOMEM;
|
|
trigger_data = kzalloc(sizeof(*trigger_data), GFP_KERNEL);
|
|
- if (!trigger_data)
|
|
+ if (!trigger_data) {
|
|
+ ret = -ENOMEM;
|
|
goto out_free;
|
|
+ }
|
|
|
|
trigger_data->count = -1;
|
|
trigger_data->ops = trigger_ops;
|
|
@@ -3117,12 +3962,23 @@ static int event_hist_trigger_func(struc
|
|
}
|
|
|
|
if (remove) {
|
|
+ if (!have_hist_trigger_match(trigger_data, file))
|
|
+ goto out_free;
|
|
+
|
|
if (hist_trigger_check_refs(trigger_data, file)) {
|
|
ret = -EBUSY;
|
|
goto out_free;
|
|
}
|
|
|
|
cmd_ops->unreg(glob+1, trigger_ops, trigger_data, file);
|
|
+
|
|
+ mutex_lock(&synth_event_mutex);
|
|
+ se_name = trace_event_name(file->event_call);
|
|
+ se = find_synth_event(se_name);
|
|
+ if (se)
|
|
+ se->ref--;
|
|
+ mutex_unlock(&synth_event_mutex);
|
|
+
|
|
ret = 0;
|
|
goto out_free;
|
|
}
|
|
@@ -3158,6 +4014,13 @@ static int event_hist_trigger_func(struc
|
|
if (ret)
|
|
goto out_unreg;
|
|
|
|
+ mutex_lock(&synth_event_mutex);
|
|
+ se_name = trace_event_name(file->event_call);
|
|
+ se = find_synth_event(se_name);
|
|
+ if (se)
|
|
+ se->ref++;
|
|
+ mutex_unlock(&synth_event_mutex);
|
|
+
|
|
/* Just return zero, not the number of registered triggers */
|
|
ret = 0;
|
|
out:
|
|
@@ -3330,3 +4193,31 @@ static __init void unregister_trigger_hi
|
|
|
|
return ret;
|
|
}
|
|
+
|
|
+static __init int trace_events_hist_init(void)
|
|
+{
|
|
+ struct dentry *entry = NULL;
|
|
+ struct dentry *d_tracer;
|
|
+ int err = 0;
|
|
+
|
|
+ d_tracer = tracing_init_dentry();
|
|
+ if (IS_ERR(d_tracer)) {
|
|
+ err = PTR_ERR(d_tracer);
|
|
+ goto err;
|
|
+ }
|
|
+
|
|
+ entry = tracefs_create_file("synthetic_events", 0644, d_tracer,
|
|
+ NULL, &synth_events_fops);
|
|
+ if (!entry) {
|
|
+ err = -ENODEV;
|
|
+ goto err;
|
|
+ }
|
|
+
|
|
+ return err;
|
|
+ err:
|
|
+ pr_warn("Could not create tracefs 'synthetic_events' entry\n");
|
|
+
|
|
+ return err;
|
|
+}
|
|
+
|
|
+fs_initcall(trace_events_hist_init);
|