Al Viro discovered some breakage with the parsing of the set_ftrace_filter

as well as the removing of function probes.
 
 This fixes the code with Al's suggestions. I also added a few selftests
 to test the broken cases such that they wont happen again.
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Merge tag 'trace-v4.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace

Pull tracing fixes from Steven Rostedt:
 "Al Viro discovered some breakage with the parsing of the
  set_ftrace_filter as well as the removing of function probes.

  This fixes the code with Al's suggestions. I also added a few
  selftests to test the broken cases such that they wont happen
  again"

* tag 'trace-v4.16-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  selftests/ftrace: Add more tests for removing of function probes
  selftests/ftrace: Add some missing glob checks
  selftests/ftrace: Have reset_ftrace_filter handle multiple instances
  selftests/ftrace: Have reset_ftrace_filter handle modules
  tracing: Fix parsing of globs with a wildcard at the beginning
  ftrace: Remove incorrect setting of glob search field

kernel/trace/ftrace.c

@@ -4456,7 +4456,6 @@ unregister_ftrace_function_probe_func(char *glob, struct trace_array *tr,
 		func_g.type = filter_parse_regex(glob, strlen(glob),
 						 &func_g.search, &not);
 		func_g.len = strlen(func_g.search);
-		func_g.search = glob;
 
 		/* we do not support '!' for function probes */
 		if (WARN_ON(not))

kernel/trace/trace_events_filter.c

@@ -400,7 +400,6 @@ enum regex_type filter_parse_regex(char *buff, int len, char **search, int *not)
 	for (i = 0; i < len; i++) {
 		if (buff[i] == '*') {
 			if (!i) {
-				*search = buff + 1;
 				type = MATCH_END_ONLY;
 			} else if (i == len - 1) {
 				if (type == MATCH_END_ONLY)
@@ -410,14 +409,14 @@ enum regex_type filter_parse_regex(char *buff, int len, char **search, int *not)
 				buff[i] = 0;
 				break;
 			} else {	/* pattern continues, use full glob */
-				type = MATCH_GLOB;
-				break;
+				return MATCH_GLOB;
 			}
 		} else if (strchr("[?\\", buff[i])) {
-			type = MATCH_GLOB;
-			break;
+			return MATCH_GLOB;
 		}
 	}
+	if (buff[0] == '*')
+		*search = buff + 1;
 
 	return type;
 }

tools/testing/selftests/ftrace/test.d/ftrace/func-filter-glob.tc

@@ -29,6 +29,12 @@ ftrace_filter_check '*schedule*' '^.*schedule.*$'
 # filter by *, end match
 ftrace_filter_check 'schedule*' '^schedule.*$'
 
+# filter by *mid*end
+ftrace_filter_check '*aw*lock' '.*aw.*lock$'
+
+# filter by start*mid*
+ftrace_filter_check 'mutex*try*' '^mutex.*try.*'
+
 # Advanced full-glob matching feature is recently supported.
 # Skip the tests if we are sure the kernel does not support it.
 if grep -q 'accepts: .* glob-matching-pattern' README ; then

tools/testing/selftests/ftrace/test.d/ftrace/func_set_ftrace_file.tc

@@ -128,6 +128,43 @@ if check_set_ftrace_filter "$FUNC1" "$FUNC2" ; then
     fail "Expected $FUNC1 and $FUNC2"
 fi
 
+test_actual() { # Compares $TMPDIR/expected with set_ftrace_filter
+    cat set_ftrace_filter | grep -v '#' | cut -d' ' -f1 | cut -d':' -f1 | sort -u > $TMPDIR/actual
+    DIFF=`diff $TMPDIR/actual $TMPDIR/expected`
+    test -z "$DIFF"
+}
+
+# Set traceoff trigger for all fuctions with "lock" in their name
+cat available_filter_functions | cut -d' ' -f1 |  grep 'lock' | sort -u > $TMPDIR/expected
+echo '*lock*:traceoff' > set_ftrace_filter
+test_actual
+
+# now remove all with 'try' in it, and end with lock
+grep -v 'try.*lock$' $TMPDIR/expected > $TMPDIR/expected2
+mv $TMPDIR/expected2 $TMPDIR/expected
+echo '!*try*lock:traceoff' >> set_ftrace_filter
+test_actual
+
+# remove all that start with "m" and end with "lock"
+grep -v '^m.*lock$' $TMPDIR/expected > $TMPDIR/expected2
+mv $TMPDIR/expected2 $TMPDIR/expected
+echo '!m*lock:traceoff' >> set_ftrace_filter
+test_actual
+
+# remove all that start with "c" and have "unlock"
+grep -v '^c.*unlock' $TMPDIR/expected > $TMPDIR/expected2
+mv $TMPDIR/expected2 $TMPDIR/expected
+echo '!c*unlock*:traceoff' >> set_ftrace_filter
+test_actual
+
+# clear all the rest
+> $TMPDIR/expected
+echo '!*:traceoff' >> set_ftrace_filter
+test_actual
+
+rm $TMPDIR/expected
+rm $TMPDIR/actual
+
 do_reset
 
 exit 0

tools/testing/selftests/ftrace/test.d/functions

@@ -37,17 +37,21 @@ reset_ftrace_filter() { # reset all triggers in set_ftrace_filter
 	if [ "$tr" = "" ]; then
 	    continue
 	fi
+	if ! grep -q "$t" set_ftrace_filter; then
+		continue;
+	fi
+	name=`echo $t | cut -d: -f1 | cut -d' ' -f1`
 	if [ $tr = "enable_event" -o $tr = "disable_event" ]; then
-	    tr=`echo $t | cut -d: -f1-4`
+	    tr=`echo $t | cut -d: -f2-4`
 	    limit=`echo $t | cut -d: -f5`
 	else
-	    tr=`echo $t | cut -d: -f1-2`
+	    tr=`echo $t | cut -d: -f2`
 	    limit=`echo $t | cut -d: -f3`
 	fi
 	if [ "$limit" != "unlimited" ]; then
 	    tr="$tr:$limit"
 	fi
-	echo "!$tr" > set_ftrace_filter
+	echo "!$name:$tr" > set_ftrace_filter
     done
 }