--- /dev/null	Fri Dec 21 15:00:01 2018
+++ new/usr/src/tools/smatch/src/check_bit_shift.c	Fri Dec 21 15:00:01 2018
@@ -0,0 +1,169 @@
+/*
+ * 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 test is used to warn about mixups between bit shifters and bit flags.
+ *
+ */
+
+#include "smatch.h"
+#include "smatch_function_hashtable.h"
+
+static int my_id;
+
+static DEFINE_HASHTABLE_INSERT(insert_struct, char, int);
+static DEFINE_HASHTABLE_SEARCH(search_struct, char, int);
+static struct hashtable *shifters;
+
+static const char *get_shifter(struct expression *expr)
+{
+	const char *name;
+	sval_t expr_value;
+	const int *shifter_value;
+
+	expr = strip_expr(expr);
+	if (expr->type != EXPR_VALUE)
+		return NULL;
+	if (!get_value(expr, &expr_value))
+		return NULL;
+	name = pos_ident(expr->pos);
+	if (!name)
+		return NULL;
+	shifter_value = search_struct(shifters, (char *)name);
+	if (!shifter_value)
+		return NULL;
+	if (sval_cmp_val(expr_value, *shifter_value) != 0)
+		return NULL;
+	return name;
+}
+
+static void match_assign(struct expression *expr)
+{
+	const char *name;
+
+	if (expr->op != SPECIAL_OR_ASSIGN)
+		return;
+	if (positions_eq(expr->pos, expr->right->pos))
+		return;
+	name = get_shifter(expr->right);
+	if (!name)
+		return;
+
+	sm_warning("'%s' is a shifter (not for '%s').",
+			name, show_special(expr->op));
+}
+
+static void match_binop(struct expression *expr)
+{
+	const char *name;
+
+	if (positions_eq(expr->pos, expr->right->pos))
+		return;
+	if (expr->op != '&')
+		return;
+	name = get_shifter(expr->right);
+	if (!name)
+		return;
+
+	sm_warning("bit shifter '%s' used for logical '%s'",
+			name, show_special(expr->op));
+}
+
+static void register_shifters(void)
+{
+	char filename[256];
+	struct token *token;
+	char *name;
+	int *val;
+
+	snprintf(filename, sizeof(filename), "%s.bit_shifters", option_project_str);
+	token = get_tokens_file(filename);
+	if (!token)
+		return;
+	if (token_type(token) != TOKEN_STREAMBEGIN)
+		return;
+	token = token->next;
+	while (token_type(token) != TOKEN_STREAMEND) {
+		if (token_type(token) != TOKEN_IDENT)
+			return;
+		name = alloc_string(show_ident(token->ident));
+		token = token->next;
+		if (token_type(token) != TOKEN_NUMBER)
+			return;
+		val = malloc(sizeof(int));
+		*val = atoi(token->number);
+		insert_struct(shifters, name, val);
+		token = token->next;
+	}
+	clear_token_alloc();
+}
+
+static void match_binop_info(struct expression *expr)
+{
+	char *name;
+	sval_t sval;
+
+	if (positions_eq(expr->pos, expr->right->pos))
+		return;
+	if (expr->op != SPECIAL_LEFTSHIFT)
+		return;
+	if (expr->right->type != EXPR_VALUE)
+		return;
+	name = pos_ident(expr->right->pos);
+	if (!name)
+		return;
+	if (!get_value(expr->right, &sval))
+		return;
+	sm_msg("info: bit shifter '%s' '%s'", name, sval_to_str(sval));
+}
+
+static void match_call(const char *fn, struct expression *expr, void *_arg_no)
+{
+	struct expression *arg_expr;
+	int arg_no = PTR_INT(_arg_no);
+	sval_t sval;
+	char *name;
+
+	arg_expr = get_argument_from_call_expr(expr->args, arg_no);
+	if (positions_eq(expr->pos, arg_expr->pos))
+		return;
+	name = pos_ident(arg_expr->pos);
+	if (!name)
+		return;
+	if (!get_value(arg_expr, &sval))
+		return;
+	sm_msg("info: bit shifter '%s' '%s'", name, sval_to_str(sval));
+}
+
+void check_bit_shift(int id)
+{
+	my_id = id;
+
+	shifters = create_function_hashtable(5000);
+	register_shifters();
+
+	add_hook(&match_assign, ASSIGNMENT_HOOK);
+	add_hook(&match_binop, BINOP_HOOK);
+
+	if (option_info) {
+		add_hook(&match_binop_info, BINOP_HOOK);
+		if (option_project == PROJ_KERNEL) {
+			add_function_hook("set_bit", &match_call, INT_PTR(0));
+			add_function_hook("test_bit", &match_call, INT_PTR(0));
+		}
+	}
+}
