--- /dev/null	Fri Dec 21 15:00:28 2018
+++ new/usr/src/tools/smatch/src/smatch_param_limit.c	Fri Dec 21 15:00:28 2018
@@ -0,0 +1,208 @@
+/*
+ * Copyright (C) 2012 Oracle.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License
+ * as published by the Free Software Foundation; either version 2
+ * of the License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, see http://www.gnu.org/copyleft/gpl.txt
+ */
+
+/*
+ * This is almost the same as smatch_param_filter.c.  The difference is that
+ * this only deals with values passed on the stack and param filter only deals
+ * with values changed so that the caller sees the new value.  It other words
+ * the key for these should always be "$" and the key for param_filter should
+ * never be "$".  Also smatch_param_set() should never use "$" as the key.
+ * Param set should work together with param_filter to determine the value that
+ * the caller sees at the end.
+ *
+ * This is for functions like this:
+ *
+ * int foo(int a)
+ * {
+ *        if (a >= 0 && a < 10) {
+ *                 a = 42;
+ *                 return 1;
+ *        }
+ *        return 0;
+ * }
+ *
+ * If we pass in 5, it returns 1.
+ *
+ * It's a bit complicated because we can't just consider the final value, we
+ * have to always consider the passed in value.
+ *
+ */
+
+#include "scope.h"
+#include "smatch.h"
+#include "smatch_extra.h"
+#include "smatch_slist.h"
+
+static int my_id;
+
+static struct stree *start_states;
+static struct stree_stack *saved_stack;
+
+static void save_start_states(struct statement *stmt)
+{
+	start_states = get_all_states_stree(SMATCH_EXTRA);
+}
+
+static void free_start_states(void)
+{
+	free_stree(&start_states);
+}
+
+static struct smatch_state *unmatched_state(struct sm_state *sm)
+{
+	struct smatch_state *state;
+
+	state = get_state(SMATCH_EXTRA, sm->name, sm->sym);
+	if (state)
+		return state;
+	return alloc_estate_whole(estate_type(sm->state));
+}
+
+struct smatch_state *get_orig_estate(const char *name, struct symbol *sym)
+{
+	struct smatch_state *state;
+
+	state = get_state(my_id, name, sym);
+	if (state)
+		return state;
+
+	state = get_state(SMATCH_EXTRA, name, sym);
+	if (state)
+		return state;
+	return alloc_estate_rl(alloc_whole_rl(get_real_base_type(sym)));
+}
+
+struct smatch_state *get_orig_estate_type(const char *name, struct symbol *sym, struct symbol *type)
+{
+	struct smatch_state *state;
+
+	state = get_state(my_id, name, sym);
+	if (state)
+		return state;
+
+	state = get_state(SMATCH_EXTRA, name, sym);
+	if (state)
+		return state;
+	return alloc_estate_rl(alloc_whole_rl(type));
+}
+
+static struct range_list *generify_mtag_range(struct smatch_state *state)
+{
+	struct range_list *rl;
+	struct data_range *drange;
+
+	if (!estate_type(state) || estate_type(state)->type != SYM_PTR)
+		return estate_rl(state);
+
+	/*
+	 * The problem is that we get too specific on our param limits when we
+	 * know exactly what pointers are passed to a function.  It gets to the
+	 * point where we say "pointer x will succeed, but everything else will
+	 * fail."  And then we introduce a new caller which passes a different
+	 * pointer and it's like, "Sorry bro, that's not possible."
+	 *
+	 */
+	rl = rl_intersection(estate_rl(state), valid_ptr_rl);
+	if (!rl)
+		return estate_rl(state);
+
+	FOR_EACH_PTR(rl, drange) {
+		if (drange->min.value != drange->max.value)
+			continue;
+		if (drange->min.value > -4096 && drange->min.value <= 0)
+			continue;
+		return rl_union(valid_ptr_rl, rl);
+	} END_FOR_EACH_PTR(drange);
+
+	return estate_rl(state);
+}
+
+static void print_return_value_param(int return_id, char *return_ranges, struct expression *expr)
+{
+	struct smatch_state *state, *old;
+	struct sm_state *tmp;
+	struct range_list *rl;
+	const char *param_name;
+	int param;
+
+	FOR_EACH_MY_SM(SMATCH_EXTRA, __get_cur_stree(), tmp) {
+		param = get_param_num_from_sym(tmp->sym);
+		if (param < 0)
+			continue;
+
+		param_name = get_param_name(tmp);
+		if (!param_name)
+			continue;
+
+		state = __get_state(my_id, tmp->name, tmp->sym);
+		if (!state)
+			state = tmp->state;
+
+		if (estate_is_whole(state) || estate_is_empty(state))
+			continue;
+		old = get_state_stree(start_states, SMATCH_EXTRA, tmp->name, tmp->sym);
+		if (old && rl_equiv(estate_rl(old), estate_rl(state)))
+			continue;
+
+		rl = generify_mtag_range(state);
+		sql_insert_return_states(return_id, return_ranges, PARAM_LIMIT,
+					 param, param_name, show_rl(rl));
+	} END_FOR_EACH_SM(tmp);
+}
+
+static void extra_mod_hook(const char *name, struct symbol *sym, struct expression *expr, struct smatch_state *state)
+{
+	struct smatch_state *orig_vals;
+	int param;
+
+	param = get_param_num_from_sym(sym);
+	if (param < 0)
+		return;
+
+	orig_vals = get_orig_estate_type(name, sym, estate_type(state));
+	set_state(my_id, name, sym, orig_vals);
+}
+
+static void match_save_states(struct expression *expr)
+{
+	push_stree(&saved_stack, start_states);
+	start_states = NULL;
+}
+
+static void match_restore_states(struct expression *expr)
+{
+	free_stree(&start_states);
+	start_states = pop_stree(&saved_stack);
+}
+
+void register_param_limit(int id)
+{
+	my_id = id;
+
+	add_hook(&save_start_states, AFTER_DEF_HOOK);
+	add_hook(&free_start_states, AFTER_FUNC_HOOK);
+
+	add_extra_mod_hook(&extra_mod_hook);
+	add_unmatched_state_hook(my_id, &unmatched_state);
+	add_merge_hook(my_id, &merge_estates);
+
+	add_hook(&match_save_states, INLINE_FN_START);
+	add_hook(&match_restore_states, INLINE_FN_END);
+
+	add_split_return_callback(&print_return_value_param);
+}
+
