ftrace: Support full glob matching

Use glob_match() to support flexible glob wildcards (*,?)
and character classes ([) for ftrace.
Since the full glob matching is slower than the current
partial matching routines(*pat, pat*, *pat*), this leaves
those routines and just add MATCH_GLOB for complex glob
expression.

e.g.
----
[root@localhost tracing]# echo 'sched*group' > set_ftrace_filter
[root@localhost tracing]# cat set_ftrace_filter
sched_free_group
sched_change_group
sched_create_group
sched_online_group
sched_destroy_group
sched_offline_group
[root@localhost tracing]# echo '[Ss]y[Ss]_*' > set_ftrace_filter
[root@localhost tracing]# head set_ftrace_filter
sys_arch_prctl
sys_rt_sigreturn
sys_ioperm
SyS_iopl
sys_modify_ldt
SyS_mmap
SyS_set_thread_area
SyS_get_thread_area
SyS_set_tid_address
sys_fork
----

Link: http://lkml.kernel.org/r/147566869501.29136.6462645009894738056.stgit@devbox

Acked-by: Namhyung Kim <namhyung@kernel.org>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>

1 files changed, 16 insertions, 1 deletions

diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c
index 9daa9b3bc6d9..e1c7e2cdc240 100644
--- a/kernel/trace/trace_events_filter.c
+++ b/kernel/trace/trace_events_filter.c
@@ -344,6 +344,12 @@ static int regex_match_end(char *str, struct regex *r, int len)
 	return 0;
 }
 
+static int regex_match_glob(char *str, struct regex *r, int len __maybe_unused)
+{
+	if (glob_match(r->pattern, str))
+		return 1;
+	return 0;
+}
 /**
  * filter_parse_regex - parse a basic regex
  * @buff:   the raw regex
@@ -380,14 +386,20 @@ enum regex_type filter_parse_regex(char *buff, int len, char **search, int *not)
 			if (!i) {
 				*search = buff + 1;
 				type = MATCH_END_ONLY;
-			} else {
+			} else if (i == len - 1) {
 				if (type == MATCH_END_ONLY)
 					type = MATCH_MIDDLE_ONLY;
 				else
 					type = MATCH_FRONT_ONLY;
 				buff[i] = 0;
 				break;
+			} else {	/* pattern continues, use full glob */
+				type = MATCH_GLOB;
+				break;
 			}
+		} else if (strchr("[?\\", buff[i])) {
+			type = MATCH_GLOB;
+			break;
 		}
 	}
 
@@ -420,6 +432,9 @@ static void filter_build_regex(struct filter_pred *pred)
 	case MATCH_END_ONLY:
 		r->match = regex_match_end;
 		break;
+	case MATCH_GLOB:
+		r->match = regex_match_glob;
+		break;
 	}
 
 	pred->not ^= not;