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[23.128.96.18]) by mx.google.com with ESMTP id w16si10125920ejb.521.2020.04.15.14.47.25; Wed, 15 Apr 2020 14:47:49 -0700 (PDT) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2503073AbgDNRyb (ORCPT + 99 others); Tue, 14 Apr 2020 13:54:31 -0400 Received: from saturn.retrosnub.co.uk ([46.235.226.198]:56986 "EHLO saturn.retrosnub.co.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729303AbgDNRy1 (ORCPT ); Tue, 14 Apr 2020 13:54:27 -0400 Received: from archlinux (cpc149474-cmbg20-2-0-cust94.5-4.cable.virginm.net [82.4.196.95]) by saturn.retrosnub.co.uk (Postfix; Retrosnub mail submission) with ESMTPSA id 8EDD29E7402; Tue, 14 Apr 2020 18:54:19 +0100 (BST) Date: Tue, 14 Apr 2020 18:54:16 +0100 From: Jonathan Cameron To: Jeremy Fertic Cc: Alexandru Ardelean , linux-iio@vger.kernel.org, linux-kernel@vger.kernel.org, alexandru.tachici@analog.com Subject: Re: [PATCH v3 1/2] iio: adc: ad7192: fix null pointer de-reference crash during probe Message-ID: <20200414185416.098062f7@archlinux> In-Reply-To: <20200413220631.GA4884@r2700x.localdomain> References: <20200413082044.81101-1-alexandru.ardelean@analog.com> <20200413220631.GA4884@r2700x.localdomain> X-Mailer: Claws Mail 3.17.5 (GTK+ 2.24.32; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 13 Apr 2020 16:06:31 -0600 Jeremy Fertic wrote: > On Mon, Apr 13, 2020 at 11:20:43AM +0300, Alexandru Ardelean wrote: > > When the 'spi_device_id' table was removed, it omitted to cleanup/fix the > > assignment: > > 'indio_dev->name = spi_get_device_id(spi)->name;' > > > > After that patch 'spi_get_device_id(spi)' returns NULL, so this crashes > > during probe with null de-ref. > > > > This change fixes this by introducing an ad7192_chip_info struct, and > > defines all part-names [that should be assigned to indio_dev->name] in a > > 'ad7192_chip_info_tbl' table. > > > > With this change, the old 'st->devid' is also moved to be a > > 'chip_info->chip_id'. And the old 'ID_AD719X' macros have been renamed to > > 'CHIPID_AD719X'. Tld identifiers have been re-purposed to be enum/index > > values in the new 'ad7192_chip_info_tbl'. > > > > This should fix the bug, and maintain the ABI for the 'indio_dev->name' > > field. > > > > Fixes: 66614ab2be38 ("staging: iio: adc: ad7192: removed spi_device_id") > > Signed-off-by: Alexandru Ardelean > > --- > > > > Changelog v2 -> v3: > > * reworked patch to introduce a chip_info struct for the part-name > > * added 2nd patch to move of-table closer to the end of the file; this > > patch is more cosmetic; has no fixes tag, but is on top of the previous > > > > Changelog v1 -> v2: > > * fix colon for Fixes tag > > * updated commit title a bit; to make it longer > > > > drivers/iio/adc/ad7192.c | 61 ++++++++++++++++++++++++++++++---------- > > 1 file changed, 46 insertions(+), 15 deletions(-) > > > > diff --git a/drivers/iio/adc/ad7192.c b/drivers/iio/adc/ad7192.c > > index 8ec28aa8fa8a..7e8662c5cb0e 100644 > > --- a/drivers/iio/adc/ad7192.c > > +++ b/drivers/iio/adc/ad7192.c > > @@ -125,10 +125,10 @@ > > #define AD7193_CH_AINCOM 0x600 /* AINCOM - AINCOM */ > > > > /* ID Register Bit Designations (AD7192_REG_ID) */ > > -#define ID_AD7190 0x4 > > -#define ID_AD7192 0x0 > > -#define ID_AD7193 0x2 > > -#define ID_AD7195 0x6 > > +#define CHIPID_AD7190 0x4 > > +#define CHIPID_AD7192 0x0 > > +#define CHIPID_AD7193 0x2 > > +#define CHIPID_AD7195 0x6 > > #define AD7192_ID_MASK 0x0F > > > > /* GPOCON Register Bit Designations (AD7192_REG_GPOCON) */ > > @@ -161,7 +161,20 @@ enum { > > AD7192_SYSCALIB_FULL_SCALE, > > }; > > > > +enum { > > + ID_AD7190, > > + ID_AD7192, > > + ID_AD7193, > > + ID_AD7195, > > +}; > > + > > +struct ad7192_chip_info { > > + unsigned int chip_id; > > + const char *name; > > +}; > > + > > struct ad7192_state { > > + const struct ad7192_chip_info *chip_info; > > struct regulator *avdd; > > struct regulator *dvdd; > > struct clk *mclk; > > @@ -172,7 +185,6 @@ struct ad7192_state { > > u32 conf; > > u32 scale_avail[8][2]; > > u8 gpocon; > > - u8 devid; > > u8 clock_sel; > > struct mutex lock; /* protect sensor state */ > > u8 syscalib_mode[8]; > > @@ -348,7 +360,7 @@ static int ad7192_setup(struct ad7192_state *st, struct device_node *np) > > > > id &= AD7192_ID_MASK; > > > > - if (id != st->devid) > > + if (id != st->chip_info->chip_id) > > dev_warn(&st->sd.spi->dev, "device ID query failed (0x%X)\n", > > id); > > > > @@ -363,7 +375,7 @@ static int ad7192_setup(struct ad7192_state *st, struct device_node *np) > > st->mode |= AD7192_MODE_REJ60; > > > > refin2_en = of_property_read_bool(np, "adi,refin2-pins-enable"); > > - if (refin2_en && st->devid != ID_AD7195) > > + if (refin2_en && st->chip_info->chip_id != CHIPID_AD7195) > > st->conf |= AD7192_CONF_REFSEL; > > > > st->conf &= ~AD7192_CONF_CHOP; > > @@ -859,11 +871,30 @@ static const struct iio_chan_spec ad7193_channels[] = { > > IIO_CHAN_SOFT_TIMESTAMP(14), > > }; > > > > +static const struct ad7192_chip_info ad7192_chip_info_tbl[] = { > > + [ID_AD7190] = { > > + .chip_id = CHIPID_AD7190, > > + .name = "ad7190", > > + }, > > + [ID_AD7192] = { > > + .chip_id = CHIPID_AD7192, > > + .name = "ad7192", > > + }, > > + [ID_AD7193] = { > > + .chip_id = CHIPID_AD7193, > > + .name = "ad7193", > > + }, > > + [ID_AD7195] = { > > + .chip_id = CHIPID_AD7195, > > + .name = "ad7195", > > + }, > > +}; > > + > > static int ad7192_channels_config(struct iio_dev *indio_dev) > > { > > struct ad7192_state *st = iio_priv(indio_dev); > > > > - switch (st->devid) { > > + switch (st->chip_info->chip_id) { > > case ID_AD7193: > > Would it be better to change this to CHIPID_AD7193? It looks like it works > the way you have it, but only by coincidence since it happens to be true > that ID_AD7193 == CHIPID_AD7193. > dropped patch from my fixes branch whilst this is resolved! Thanks, Jonathan > Jeremy > > > indio_dev->channels = ad7193_channels; > > indio_dev->num_channels = ARRAY_SIZE(ad7193_channels); > > @@ -878,10 +909,10 @@ static int ad7192_channels_config(struct iio_dev *indio_dev) > > } > > > > static const struct of_device_id ad7192_of_match[] = { > > - { .compatible = "adi,ad7190", .data = (void *)ID_AD7190 }, > > - { .compatible = "adi,ad7192", .data = (void *)ID_AD7192 }, > > - { .compatible = "adi,ad7193", .data = (void *)ID_AD7193 }, > > - { .compatible = "adi,ad7195", .data = (void *)ID_AD7195 }, > > + { .compatible = "adi,ad7190", .data = &ad7192_chip_info_tbl[ID_AD7190] }, > > + { .compatible = "adi,ad7192", .data = &ad7192_chip_info_tbl[ID_AD7192] }, > > + { .compatible = "adi,ad7193", .data = &ad7192_chip_info_tbl[ID_AD7193] }, > > + { .compatible = "adi,ad7195", .data = &ad7192_chip_info_tbl[ID_AD7195] }, > > {} > > }; > > MODULE_DEVICE_TABLE(of, ad7192_of_match); > > @@ -938,16 +969,16 @@ static int ad7192_probe(struct spi_device *spi) > > } > > > > spi_set_drvdata(spi, indio_dev); > > - st->devid = (unsigned long)of_device_get_match_data(&spi->dev); > > + st->chip_info = of_device_get_match_data(&spi->dev); > > indio_dev->dev.parent = &spi->dev; > > - indio_dev->name = spi_get_device_id(spi)->name; > > + indio_dev->name = st->chip_info->name; > > indio_dev->modes = INDIO_DIRECT_MODE; > > > > ret = ad7192_channels_config(indio_dev); > > if (ret < 0) > > goto error_disable_dvdd; > > > > - if (st->devid == ID_AD7195) > > + if (st->chip_info->chip_id == CHIPID_AD7195) > > indio_dev->info = &ad7195_info; > > else > > indio_dev->info = &ad7192_info; > > -- > > 2.17.1 > >