From mboxrd@z Thu Jan 1 00:00:00 1970 From: Daniel Thompson Date: Mon, 07 Jan 2019 11:12:14 +0000 Subject: Re: [PATCH] v2 bakclight: fix missing checks in ambient_light_zone_store Message-Id: <20190107111214.hl3issz5yzs5muqc@holly.lan> List-Id: References: <20190105184807.4827-1-pakki001@umn.edu> In-Reply-To: <20190105184807.4827-1-pakki001@umn.edu> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: Aditya Pakki Cc: linux-fbdev@vger.kernel.org, Bartlomiej Zolnierkiewicz , Jingoo Han , kjlu@umn.edu, linux-kernel@vger.kernel.org, dri-devel@lists.freedesktop.org, Lee Jones On Sat, Jan 05, 2019 at 12:48:07PM -0600, Aditya Pakki wrote: > In adp8870_bl_ambient_light_zone_store, set, clear, and write I'm curious... What attracted you to this particular _store function? AFAICT the same ignoring of return values occurs in other _store functions in this file? > can return an error but are not checked. The fix adds a check for these > cases and returns -1 to match the return type (ssize_t). This isn't right. The caller of the store function expects -errno values (this is the default for almost all kernel functions). > Signed-off-by: Aditya Pakki > --- > drivers/video/backlight/adp8870_bl.c | 16 +++++++++++++--- > 1 file changed, 13 insertions(+), 3 deletions(-) > > diff --git a/drivers/video/backlight/adp8870_bl.c b/drivers/video/backlight/adp8870_bl.c > index 8d50e0299578..56a640587a82 100644 > --- a/drivers/video/backlight/adp8870_bl.c > +++ b/drivers/video/backlight/adp8870_bl.c > @@ -800,10 +800,14 @@ static ssize_t adp8870_bl_ambient_light_zone_store(struct device *dev, > > if (val = 0) { > /* Enable automatic ambient light sensing */ > - adp8870_set_bits(data->client, ADP8870_MDCR, CMP_AUTOEN); > + ret = adp8870_set_bits(data->client, ADP8870_MDCR, CMP_AUTOEN); > + if (ret < 0) > + goto adp8870_bl_err; There's nothing *wrong* with goto for error handling but is it really needed here (there is no recovery code)? > } else if ((val > 0) && (val < 6)) { > /* Disable automatic ambient light sensing */ > - adp8870_clr_bits(data->client, ADP8870_MDCR, CMP_AUTOEN); > + ret = adp8870_clr_bits(data->client, ADP8870_MDCR, CMP_AUTOEN); > + if (ret < 0) > + goto adp8870_bl_err; +1 > > /* Set user supplied ambient light zone */ > mutex_lock(&data->lock); > @@ -811,12 +815,18 @@ static ssize_t adp8870_bl_ambient_light_zone_store(struct device *dev, > if (!ret) { > reg_val &= ~(CFGR_BLV_MASK << CFGR_BLV_SHIFT); > reg_val |= (val - 1) << CFGR_BLV_SHIFT; > - adp8870_write(data->client, ADP8870_CFGR, reg_val); > + ret = adp8870_write(data->client, ADP8870_CFGR, > + reg_val); > } > mutex_unlock(&data->lock); > + if (ret < 0) > + goto adp8870_bl_err; +1 Daniel. > } > > return count; > + > +adp8870_bl_err: > + return -1; > } > static DEVICE_ATTR(ambient_light_zone, 0664, > adp8870_bl_ambient_light_zone_show, > -- > 2.17.1 >