tracing: Add support for 'synthetic' events
Synthetic events are user-defined events generated from hist trigger
variables saved from one or more other events.
To define a synthetic event, the user writes a simple specification
consisting of the name of the new event along with one or more
variables and their type(s), to the tracing/synthetic_events file.
For instance, the following creates a new event named 'wakeup_latency'
with 3 fields: lat, pid, and prio:
# echo 'wakeup_latency u64 lat; pid_t pid; int prio' >> \
/sys/kernel/debug/tracing/synthetic_events
Reading the tracing/synthetic_events file lists all the
currently-defined synthetic events, in this case the event we defined
above:
# cat /sys/kernel/debug/tracing/synthetic_events
wakeup_latency u64 lat; pid_t pid; int prio
At this point, the synthetic event is ready to use, and a histogram
can be defined using it:
# echo 'hist:keys=pid,prio,lat.log2:sort=pid,lat' >> \
/sys/kernel/debug/tracing/events/synthetic/wakeup_latency/trigger
The new event is created under the tracing/events/synthetic/ directory
and looks and behaves just like any other event:
# ls /sys/kernel/debug/tracing/events/synthetic/wakeup_latency
enable filter format hist id trigger
Although a histogram can be defined for it, nothing will happen until
an action tracing that event via the trace_synth() function occurs.
The trace_synth() function is very similar to all the other trace_*
invocations spread throughout the kernel, except in this case the
trace_ function and its corresponding tracepoint isn't statically
generated but defined by the user at run-time.
How this can be automatically hooked up via a hist trigger 'action' is
discussed in a subsequent patch.
Link: http://lkml.kernel.org/r/c68df2284b7d172669daf9be29db62ad49bbc559.1516069914.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
[fix noderef.cocci warnings, sizeof pointer for kcalloc of event->fields]
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
This commit is contained in:
Tom Zanussi
Steven Rostedt (VMware)
parent
0212e2aa30
commit
4b147936fa
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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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#define STR_VAR_LEN_MAX 32 /* must be multiple of sizeof(u64) */
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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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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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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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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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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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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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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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event->n_u64 = n_u64;
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return ret;
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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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return true;
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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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return false;
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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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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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end = strchr(type, ']');
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if (!end || end < start)
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return -EINVAL;
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len = end - start;
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if (len > 3)
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return -EINVAL;
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strncpy(buf, start, len);
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buf[len] = '\0';
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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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if (size > STR_VAR_LEN_MAX)
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return -EINVAL;
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return size;
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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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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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return size;
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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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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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return fmt;
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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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entry = (struct synth_trace_event *)iter->ent;
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se = container_of(event, struct synth_event, call.event);
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trace_seq_printf(s, "%s: ", se->name);
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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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fmt = synth_field_fmt(se->fields[i]->type);
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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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snprintf(print_fmt, sizeof(print_fmt), "%%s=%s%%s", fmt);
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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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return trace_handle_return(s);
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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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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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event = trace_file->event_call->data;
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if (trace_trigger_soft_disabled(trace_file))
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return;
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fields_size = event->n_u64 * sizeof(u64);
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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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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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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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trace_event_buffer_commit(&fbuffer);
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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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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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/* 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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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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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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/* 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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/* 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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print_fmt = kmalloc(len + 1, GFP_KERNEL);
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if (!print_fmt)
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return -ENOMEM;
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/* Second: actually write the @print_fmt */
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__set_synth_event_print_fmt(event, print_fmt, len + 1);
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call->print_fmt = print_fmt;
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return 0;
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}
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static void free_synth_field(struct synth_field *field)
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{
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kfree(field->type);
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kfree(field->name);
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kfree(field);
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}
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static struct synth_field *parse_synth_field(char *field_type,
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char *field_name)
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{
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struct synth_field *field;
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int len, ret = 0;
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char *array;
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if (field_type[0] == ';')
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field_type++;
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len = strlen(field_name);
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if (field_name[len - 1] == ';')
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field_name[len - 1] = '\0';
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field = kzalloc(sizeof(*field), GFP_KERNEL);
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if (!field)
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return ERR_PTR(-ENOMEM);
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len = strlen(field_type) + 1;
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array = strchr(field_name, '[');
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if (array)
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len += strlen(array);
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field->type = kzalloc(len, GFP_KERNEL);
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if (!field->type) {
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ret = -ENOMEM;
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goto free;
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}
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strcat(field->type, field_type);
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if (array) {
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strcat(field->type, array);
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*array = '\0';
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}
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field->size = synth_field_size(field->type);
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if (!field->size) {
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ret = -EINVAL;
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goto free;
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}
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if (synth_field_is_string(field->type))
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field->is_string = true;
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field->is_signed = synth_field_signed(field->type);
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field->name = kstrdup(field_name, GFP_KERNEL);
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if (!field->name) {
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ret = -ENOMEM;
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goto free;
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}
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out:
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return field;
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free:
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free_synth_field(field);
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field = ERR_PTR(ret);
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goto out;
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}
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static void free_synth_tracepoint(struct tracepoint *tp)
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{
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if (!tp)
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return;
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kfree(tp->name);
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kfree(tp);
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}
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static struct tracepoint *alloc_synth_tracepoint(char *name)
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{
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struct tracepoint *tp;
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tp = kzalloc(sizeof(*tp), GFP_KERNEL);
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if (!tp)
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return ERR_PTR(-ENOMEM);
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tp->name = kstrdup(name, GFP_KERNEL);
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if (!tp->name) {
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kfree(tp);
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return ERR_PTR(-ENOMEM);
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}
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return tp;
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}
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typedef void (*synth_probe_func_t) (void *__data, u64 *var_ref_vals,
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unsigned int var_ref_idx);
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static inline void trace_synth(struct synth_event *event, u64 *var_ref_vals,
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unsigned int var_ref_idx)
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{
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struct tracepoint *tp = event->tp;
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if (unlikely(atomic_read(&tp->key.enabled) > 0)) {
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struct tracepoint_func *probe_func_ptr;
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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 event_trigger_data *data,
|
|||
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_event_file *file)
|
|||
{
|
||||
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_event_file *file)
|
|||
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(struct event_command *cmd_ops,
|
|||
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(struct event_command *cmd_ops,
|
|||
|
||||
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(struct event_command *cmd_ops,
|
|||
}
|
||||
|
||||
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 @@ enable:
|
|||
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 @@ __init int register_trigger_hist_enable_disable_cmds(void)
|
|||
|
||||
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);
|
||||
|
|
|
|||
Loading…
Reference in New Issue