tracing: Add hist trigger 'syscall' modifier
Allow users to have syscall id fields displayed as syscall names in
the output by appending '.syscall' to field names:
# echo hist:keys=aaa.syscall ... \
[ if filter] > event/trigger
Link: http://lkml.kernel.org/r/2bab1e59933d76a14b545bd2e02f80b8b08ac4d3.1457029949.git.tom.zanussi@linux.intel.com
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Tested-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c
index 58a8bee..0dd23c5 100644
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -3858,7 +3858,8 @@
"\t .hex display a number as a hex value\n"
"\t .sym display an address as a symbol\n"
"\t .sym-offset display an address as a symbol and offset\n"
- "\t .execname display a common_pid as a program name\n\n"
+ "\t .execname display a common_pid as a program name\n"
+ "\t .syscall display a syscall id as a syscall name\n\n"
"\t The 'pause' parameter can be used to pause an existing hist\n"
"\t trigger or to start a hist trigger but not log any events\n"
"\t until told to do so. 'continue' can be used to start or\n"
diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c
index 227e6c2..f9e7ecb 100644
--- a/kernel/trace/trace_events_hist.c
+++ b/kernel/trace/trace_events_hist.c
@@ -84,6 +84,7 @@
HIST_FIELD_FL_SYM = 16,
HIST_FIELD_FL_SYM_OFFSET = 32,
HIST_FIELD_FL_EXECNAME = 64,
+ HIST_FIELD_FL_SYSCALL = 128,
};
struct hist_trigger_attrs {
@@ -474,6 +475,8 @@
else if ((strcmp(field_str, "execname") == 0) &&
(strcmp(field_name, "common_pid") == 0))
flags |= HIST_FIELD_FL_EXECNAME;
+ else if (strcmp(field_str, "syscall") == 0)
+ flags |= HIST_FIELD_FL_SYSCALL;
else {
ret = -EINVAL;
goto out;
@@ -854,6 +857,16 @@
uval = *(u64 *)(key + key_field->offset);
seq_printf(m, "%s: %-16s[%10llu]",
key_field->field->name, comm, uval);
+ } else if (key_field->flags & HIST_FIELD_FL_SYSCALL) {
+ const char *syscall_name;
+
+ uval = *(u64 *)(key + key_field->offset);
+ syscall_name = get_syscall_name(uval);
+ if (!syscall_name)
+ syscall_name = "unknown_syscall";
+
+ seq_printf(m, "%s: %-30s[%3llu]",
+ key_field->field->name, syscall_name, uval);
} else if (key_field->flags & HIST_FIELD_FL_STRING) {
seq_printf(m, "%s: %-50s", key_field->field->name,
(char *)(key + key_field->offset));
@@ -975,6 +988,8 @@
flags_str = "sym-offset";
else if (hist_field->flags & HIST_FIELD_FL_EXECNAME)
flags_str = "execname";
+ else if (hist_field->flags & HIST_FIELD_FL_SYSCALL)
+ flags_str = "syscall";
return flags_str;
}