From patchwork Tue Dec 8 14:36:40 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Lorenzo Bianconi X-Patchwork-Id: 11958749 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-17.0 required=3.0 tests=BAYES_00,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id E1901C433FE for ; Tue, 8 Dec 2020 14:37:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9C59823A6A for ; Tue, 8 Dec 2020 14:37:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729335AbgLHOh2 (ORCPT ); Tue, 8 Dec 2020 09:37:28 -0500 Received: from mail.kernel.org ([198.145.29.99]:49502 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729308AbgLHOh2 (ORCPT ); Tue, 8 Dec 2020 09:37:28 -0500 From: Lorenzo Bianconi Authentication-Results: mail.kernel.org; dkim=permerror (bad message/signature format) To: jic23@kernel.org Cc: lorenzo.bianconi@redhat.com, linux-iio@vger.kernel.org, linus.walleij@linaro.org, denis.ciocca@st.com Subject: [PATCH v3] iio: common: st_sensors: fix possible infinite loop in st_sensors_irq_thread Date: Tue, 8 Dec 2020 15:36:40 +0100 Message-Id: X-Mailer: git-send-email 2.28.0 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-iio@vger.kernel.org Return a boolean value in st_sensors_new_samples_available routine in order to avoid an infinite loop in st_sensors_irq_thread if stat_drdy.addr is not defined or stat_drdy read fails Fixes: 90efe05562921 ("iio: st_sensors: harden interrupt handling") Reported-by: Jonathan Cameron Reviewed-by: Linus Walleij Signed-off-by: Lorenzo Bianconi --- Changes since v2: - return -EOPNOTSUPP if the drv requests edge IRQ and the sensor does not support status register Changes since v1: - return true if the sensor does not have stat_drdy register --- .../common/st_sensors/st_sensors_trigger.c | 31 ++++++++++--------- 1 file changed, 17 insertions(+), 14 deletions(-) diff --git a/drivers/iio/common/st_sensors/st_sensors_trigger.c b/drivers/iio/common/st_sensors/st_sensors_trigger.c index 0507283bd4c1..2dbd2646e44e 100644 --- a/drivers/iio/common/st_sensors/st_sensors_trigger.c +++ b/drivers/iio/common/st_sensors/st_sensors_trigger.c @@ -23,35 +23,31 @@ * @sdata: Sensor data. * * returns: - * 0 - no new samples available - * 1 - new samples available - * negative - error or unknown + * false - no new samples available or read error + * true - new samples available */ -static int st_sensors_new_samples_available(struct iio_dev *indio_dev, - struct st_sensor_data *sdata) +static bool st_sensors_new_samples_available(struct iio_dev *indio_dev, + struct st_sensor_data *sdata) { int ret, status; /* How would I know if I can't check it? */ if (!sdata->sensor_settings->drdy_irq.stat_drdy.addr) - return -EINVAL; + return true; /* No scan mask, no interrupt */ if (!indio_dev->active_scan_mask) - return 0; + return false; ret = regmap_read(sdata->regmap, sdata->sensor_settings->drdy_irq.stat_drdy.addr, &status); if (ret < 0) { dev_err(sdata->dev, "error checking samples available\n"); - return ret; + return false; } - if (status & sdata->sensor_settings->drdy_irq.stat_drdy.mask) - return 1; - - return 0; + return !!(status & sdata->sensor_settings->drdy_irq.stat_drdy.mask); } /** @@ -180,9 +176,15 @@ int st_sensors_allocate_trigger(struct iio_dev *indio_dev, /* Tell the interrupt handler that we're dealing with edges */ if (irq_trig == IRQF_TRIGGER_FALLING || - irq_trig == IRQF_TRIGGER_RISING) + irq_trig == IRQF_TRIGGER_RISING) { + if (!sdata->sensor_settings->drdy_irq.stat_drdy.addr) { + dev_err(&indio_dev->dev, + "edge IRQ not supported w/o stat register.\n"); + err = -EOPNOTSUPP; + goto iio_trigger_free; + } sdata->edge_irq = true; - else + } else { /* * If we're not using edges (i.e. level interrupts) we * just mask off the IRQ, handle one interrupt, then @@ -190,6 +192,7 @@ int st_sensors_allocate_trigger(struct iio_dev *indio_dev, * interrupt handler top half again and start over. */ irq_trig |= IRQF_ONESHOT; + } /* * If the interrupt pin is Open Drain, by definition this