From patchwork Mon Mar 8 09:23:22 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?q?Uwe_Kleine-K=C3=B6nig?= X-Patchwork-Id: 1448929 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Authentication-Results: ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org (client-ip=23.128.96.18; helo=vger.kernel.org; envelope-from=linux-pwm-owner@vger.kernel.org; receiver=) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by ozlabs.org (Postfix) with ESMTP id 4DvCbb4l1Qz9sWT for ; Mon, 8 Mar 2021 20:24:43 +1100 (AEDT) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230034AbhCHJYC (ORCPT ); Mon, 8 Mar 2021 04:24:02 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:46912 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229468AbhCHJXb (ORCPT ); Mon, 8 Mar 2021 04:23:31 -0500 Received: from metis.ext.pengutronix.de (metis.ext.pengutronix.de [IPv6:2001:67c:670:201:290:27ff:fe1d:cc33]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4677EC06174A for ; Mon, 8 Mar 2021 01:23:30 -0800 (PST) Received: from ptx.hi.pengutronix.de ([2001:67c:670:100:1d::c0]) by metis.ext.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1lJC6q-00077I-8Z; Mon, 08 Mar 2021 10:23:28 +0100 Received: from ukl by ptx.hi.pengutronix.de with local (Exim 4.92) (envelope-from ) id 1lJC6n-0008EA-MI; Mon, 08 Mar 2021 10:23:25 +0100 From: =?utf-8?q?Uwe_Kleine-K=C3=B6nig?= To: Thierry Reding , Lee Jones Cc: linux-pwm@vger.kernel.org, kernel@pengutronix.de Subject: [PATCH] pwm: soften potential loss of precision in compat code Date: Mon, 8 Mar 2021 10:23:22 +0100 Message-Id: <20210308092322.24502-1-u.kleine-koenig@pengutronix.de> X-Mailer: git-send-email 2.30.1 MIME-Version: 1.0 X-SA-Exim-Connect-IP: 2001:67c:670:100:1d::c0 X-SA-Exim-Mail-From: ukl@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-pwm@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pwm@vger.kernel.org The legacy callback .config() only uses int for period and duty_cycle while the corresponding values in struct pwm_state are u64. To prevent that a value bigger than INT_MAX is discarded to a very small value, explicitly check for big values and pass INT_MAX instead of discarding. Signed-off-by: Uwe Kleine-König --- drivers/pwm/core.c | 15 +++++++++++++-- 1 file changed, 13 insertions(+), 2 deletions(-) diff --git a/drivers/pwm/core.c b/drivers/pwm/core.c index c4d5c0667137..4058d3c86a45 100644 --- a/drivers/pwm/core.c +++ b/drivers/pwm/core.c @@ -599,9 +599,20 @@ int pwm_apply_state(struct pwm_device *pwm, const struct pwm_state *state) if (state->period != pwm->state.period || state->duty_cycle != pwm->state.duty_cycle) { + int duty_cycle, period; + + if (state->period < INT_MAX) + period = state->period; + else + period = INT_MAX; + + if (state->duty_cycle < INT_MAX) + duty_cycle = state->duty_cycle; + else + duty_cycle = INT_MAX; + err = chip->ops->config(pwm->chip, pwm, - state->duty_cycle, - state->period); + duty_cycle, period); if (err) return err;