linux-kernel - Re: [PATCH 23/35] media: dvb-frontends: tda10048: Use the right div

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Date: Tue, 16 Apr 2024 13:27:41 +0300
From: Dan Carpenter <dan.carpenter@...aro.org>
To: Ricardo Ribalda <ribalda@...omium.org>
Cc: Martin Tuma <martin.tuma@...iteqautomotive.com>,
	Mauro Carvalho Chehab <mchehab@...nel.org>,
	Laurent Pinchart <laurent.pinchart@...asonboard.com>,
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Subject: Re: [PATCH 23/35] media: dvb-frontends: tda10048: Use the right div

I have created a Smatch check to warn about code like this:

drivers/media/dvb-frontends/tda10048.c:345 tda10048_set_wref() warn: unnecessary div64_u64(): divisor = '0-u32max'

regards,
dan carpenter

/*
 * Copyright 2024 Linaro Ltd.
 *
 * 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
 */

#include "smatch.h"
#include "smatch_extra.h"

static int my_id;

static const sval_t uint_max  = { .type = &uint_ctype, .value = UINT_MAX };

static void match_div64_u64(struct expression *expr)
{
	struct range_list *rl;

	get_real_absolute_rl(expr, &rl);
	if (sval_cmp(rl_max(rl), uint_max) > 0)
		return;
	sm_warning("unnecessary div64_u64(): divisor = '%s'", show_rl(rl));
}

void check_unnecessary_div64_u64(int id)
{
	my_id = id;

	if (option_project != PROJ_KERNEL)
		return;

	add_param_key_expr_hook("div64_u64", match_div64_u64, 1, "$", NULL);
}