diff --git a/cmds/record.c b/cmds/record.c
index ec40ca179..26537df6a 100644
--- a/cmds/record.c
+++ b/cmds/record.c
@@ -1625,7 +1625,7 @@ static void check_binary(struct uftrace_opts *opts)
 		if (!opts->force && !opts->patch)
 			pr_err_ns(SCRIPT_MSG, opts->exename);
 
-		script = str_ltrim(script);
+		script = str_trim(script);
 
 		/* ignore options */
 		p = strchr(script, ' ');
@@ -2188,7 +2188,7 @@ int do_child_exec(int ready, struct uftrace_opts *opts, int argc, char *argv[])
 		if (strstr(shebang, "python"))
 			is_python = true;
 #endif
-		s = str_ltrim(shebang);
+		s = str_trim(shebang);
 
 		p = strchr(s, ' ');
 		if (p != NULL)
diff --git a/libmcount/dynamic.c b/libmcount/dynamic.c
index c9c058eb5..6e7b56dd9 100644
--- a/libmcount/dynamic.c
+++ b/libmcount/dynamic.c
@@ -384,10 +384,17 @@ static bool match_pattern_module(char *pathname)
 	return ret;
 }
 
-static bool match_pattern_list(struct uftrace_mmap *map, char *soname, char *sym_name)
+/**
+ * match_pattern_list - match a symbol name against a pattern list
+ * @map - memory map of the symbol
+ * @soname - name of the module
+ * @sym_name - name of the symbol
+ * @return - -1 if match negative, 1 if match positive, 0 if no match
+ */
+static int match_pattern_list(struct uftrace_mmap *map, char *soname, char *sym_name)
 {
 	struct patt_list *pl;
-	bool ret = false;
+	int ret = 0;
 	char *libname = basename(map->libname);
 
 	list_for_each_entry(pl, &patterns, list) {
@@ -398,7 +405,7 @@ static bool match_pattern_list(struct uftrace_mmap *map, char *soname, char *sym
 			continue;
 
 		if (match_filter_pattern(&pl->patt, sym_name))
-			ret = pl->positive;
+			ret = pl->positive ? 1 : -1;
 	}
 
 	return ret;
@@ -410,7 +417,6 @@ static void parse_pattern_list(char *patch_funcs, char *def_mod, enum uftrace_pa
 	char *name;
 	int j;
 	struct patt_list *pl;
-	bool all_negative = true;
 
 	strv_split(&funcs, patch_funcs, ";");
 
@@ -421,10 +427,8 @@ static void parse_pattern_list(char *patch_funcs, char *def_mod, enum uftrace_pa
 
 		if (name[0] == '!')
 			name++;
-		else {
+		else
 			pl->positive = true;
-			all_negative = false;
-		}
 
 		delim = strchr(name, '@');
 		if (delim == NULL) {
@@ -439,20 +443,6 @@ static void parse_pattern_list(char *patch_funcs, char *def_mod, enum uftrace_pa
 		list_add_tail(&pl->list, &patterns);
 	}
 
-	/* prepend match-all pattern, if all patterns are negative */
-	if (all_negative) {
-		pl = xzalloc(sizeof(*pl));
-		pl->positive = true;
-		pl->module = xstrdup(def_mod);
-
-		if (ptype == PATT_REGEX)
-			init_filter_pattern(ptype, &pl->patt, ".");
-		else
-			init_filter_pattern(PATT_GLOB, &pl->patt, "*");
-
-		list_add(&pl->list, &patterns);
-	}
-
 	strv_free(&funcs);
 }
 
@@ -487,12 +477,6 @@ static bool skip_sym(struct uftrace_symbol *sym, struct mcount_dynamic_info *mdi
 	if (sym->type != ST_LOCAL_FUNC && sym->type != ST_GLOBAL_FUNC && sym->type != ST_WEAK_FUNC)
 		return true;
 
-	if (!match_pattern_list(map, soname, sym->name)) {
-		if (mcount_unpatch_func(mdi, sym, &disasm) == 0)
-			stats.unpatch++;
-		return true;
-	}
-
 	return false;
 }
 
@@ -559,6 +543,7 @@ static void patch_normal_func_matched(struct mcount_dynamic_info *mdi, struct uf
 	unsigned i;
 	struct uftrace_symbol *sym;
 	bool found = false;
+	int match;
 	char *soname = get_soname(map->libname);
 
 	symtab = &map->mod->symtab;
@@ -568,9 +553,15 @@ static void patch_normal_func_matched(struct mcount_dynamic_info *mdi, struct uf
 
 		if (skip_sym(sym, mdi, map, soname))
 			continue;
-
 		found = true;
-		mcount_patch_func_with_stats(mdi, sym);
+
+		match = match_pattern_list(map, soname, sym->name);
+		if (!match)
+			continue;
+		else if (match == 1)
+			mcount_patch_func_with_stats(mdi, sym);
+		else
+			mcount_unpatch_func(mdi, sym, NULL);
 	}
 
 	if (!found)
@@ -846,27 +837,27 @@ TEST_CASE(dynamic_pattern_list)
 	pr_dbg("check simple match with default module\n");
 	parse_pattern_list("abc;!def", "main", PATT_SIMPLE);
 
-	TEST_EQ(match_pattern_list(main_map, NULL, "abc"), true);
-	TEST_EQ(match_pattern_list(main_map, NULL, "def"), false);
-	TEST_EQ(match_pattern_list(other_map, NULL, "xyz"), false);
+	TEST_EQ(match_pattern_list(main_map, NULL, "abc"), 1);
+	TEST_EQ(match_pattern_list(main_map, NULL, "def"), -1);
+	TEST_EQ(match_pattern_list(other_map, NULL, "xyz"), 0);
 
 	release_pattern_list();
 
 	pr_dbg("check negative regex match with default module\n");
 	parse_pattern_list("!^a", "main", PATT_REGEX);
 
-	TEST_EQ(match_pattern_list(main_map, NULL, "abc"), false);
-	TEST_EQ(match_pattern_list(main_map, NULL, "def"), true);
-	TEST_EQ(match_pattern_list(other_map, NULL, "xyz"), false);
+	TEST_EQ(match_pattern_list(main_map, NULL, "abc"), -1);
+	TEST_EQ(match_pattern_list(main_map, NULL, "def"), 0);
+	TEST_EQ(match_pattern_list(other_map, NULL, "xyz"), 0);
 
 	release_pattern_list();
 
 	pr_dbg("check wildcard match with other module\n");
 	parse_pattern_list("*@other", "main", PATT_GLOB);
 
-	TEST_EQ(match_pattern_list(main_map, NULL, "abc"), false);
-	TEST_EQ(match_pattern_list(main_map, NULL, "def"), false);
-	TEST_EQ(match_pattern_list(other_map, NULL, "xyz"), true);
+	TEST_EQ(match_pattern_list(main_map, NULL, "abc"), 0);
+	TEST_EQ(match_pattern_list(main_map, NULL, "def"), 0);
+	TEST_EQ(match_pattern_list(other_map, NULL, "xyz"), 1);
 
 	release_pattern_list();
 
diff --git a/utils/utils.c b/utils/utils.c
index cd49bb8da..953ba06e8 100644
--- a/utils/utils.c
+++ b/utils/utils.c
@@ -595,33 +595,33 @@ char *strjoin(char *left, char *right, const char *delim)
 }
 
 /**
- * str_ltrim - to trim left spaces
+ * str_trim - to trim all spaces
  * @str: input string
  *
- * This function make @str to left trimmed @str
+ * This function make @str to right trimmed @str
  */
-char *str_ltrim(char *str)
+char *str_trim(char *str)
 {
+	int i = 0;
+	int j = 0;
+	bool spaceFound = false;
+
 	if (!str)
 		return NULL;
-	while (isspace((unsigned char)*str)) {
-		str++;
+
+	while (str[j]) {
+		if (str[j] != ' ' || !spaceFound) {
+			str[i] = str[j];
+			i++;
+			spaceFound = (str[j] == ' ');
+		}
+		j++;
 	}
-	return str;
-}
 
-/**
- * str_rtrim - to trim right spaces
- * @str: input string
- *
- * This function make @str to right trimmed @str
- */
-char *str_rtrim(char *str)
-{
-	char *p = strchr(str, '\0');
-	while (--p >= str && isspace(*p))
-		;
-	*(p + 1) = '\0';
+	if (i > 0 && str[i - 1] == ' ')
+		i--;
+
+	str[i] = '\0';
 	return str;
 }
 
diff --git a/utils/utils.h b/utils/utils.h
index 393def811..9dc03f8fc 100644
--- a/utils/utils.h
+++ b/utils/utils.h
@@ -389,8 +389,7 @@ void strv_append(struct strv *strv, const char *str);
 void strv_replace(struct strv *strv, int idx, const char *str);
 char *strv_join(struct strv *strv, const char *delim);
 void strv_free(struct strv *strv);
-char *str_ltrim(char *str);
-char *str_rtrim(char *str);
+char *str_trim(char *str);
 
 char **parse_cmdline(char *cmd, int *argc);
 void free_parsed_cmdline(char **argv);