| Message ID | 20210226232229.1076199-1-colin.king@canonical.com |
|---|---|
| State | New |
| Headers | show |
| Series | media: i2c: adp1653: fix error handling from a call to adp1653_get_fault | expand |
On Fri, Feb 26, 2021 at 11:22:29PM +0000, Colin King wrote: > From: Colin Ian King <colin.king@canonical.com> > > The error check on rval from the call to adp1653_get_fault currently > returns if rval is non-zero. This appears to be incorrect as the > following if statement checks for various bit settings in rval so > clearly rval is expected to be non-zero at that point. Coverity > flagged the if statement up as deadcode. Fix this so the error > return path only occurs when rval is negative. > > Addresses-Coverity: ("Logically dead code") > Fixes: 287980e49ffc ("remove lots of IS_ERR_VALUE abuses") > Signed-off-by: Colin Ian King <colin.king@canonical.com> > --- > drivers/media/i2c/adp1653.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/media/i2c/adp1653.c b/drivers/media/i2c/adp1653.c > index 522a0b10e415..1a4878385394 100644 > --- a/drivers/media/i2c/adp1653.c > +++ b/drivers/media/i2c/adp1653.c > @@ -170,7 +170,7 @@ static int adp1653_set_ctrl(struct v4l2_ctrl *ctrl) > int rval; > > rval = adp1653_get_fault(flash); > - if (rval) > + if (rval < 0) > return rval; This is good, but all the other callers need to fixed as well: 140 static int adp1653_get_ctrl(struct v4l2_ctrl *ctrl) 141 { 142 struct adp1653_flash *flash = 143 container_of(ctrl->handler, struct adp1653_flash, ctrls); 144 int rval; 145 146 rval = adp1653_get_fault(flash); 147 if (rval) 148 return rval; 149 150 ctrl->cur.val = 0; 151 152 if (flash->fault & ADP1653_REG_FAULT_FLT_SCP) ^^^^^^^^^^^^ flash->fault is the equivalent of "rval" for non-negative returns so this condition can never be true. We should never be returning these weird firmware ADP1653_REG_FAULT_FLT_SCP fault codes to the v4l2 layers. 153 ctrl->cur.val |= V4L2_FLASH_FAULT_SHORT_CIRCUIT; 154 if (flash->fault & ADP1653_REG_FAULT_FLT_OT) 155 ctrl->cur.val |= V4L2_FLASH_FAULT_OVER_TEMPERATURE; 156 if (flash->fault & ADP1653_REG_FAULT_FLT_TMR) 157 ctrl->cur.val |= V4L2_FLASH_FAULT_TIMEOUT; 158 if (flash->fault & ADP1653_REG_FAULT_FLT_OV) 159 ctrl->cur.val |= V4L2_FLASH_FAULT_OVER_VOLTAGE; 160 161 flash->fault = 0; 162 163 return 0; 164 } regards, dan carpenter
Hi Dan, Colin, On Sat, Feb 27, 2021 at 01:17:20PM +0300, Dan Carpenter wrote: > On Fri, Feb 26, 2021 at 11:22:29PM +0000, Colin King wrote: > > From: Colin Ian King <colin.king@canonical.com> > > > > The error check on rval from the call to adp1653_get_fault currently > > returns if rval is non-zero. This appears to be incorrect as the > > following if statement checks for various bit settings in rval so > > clearly rval is expected to be non-zero at that point. Coverity > > flagged the if statement up as deadcode. Fix this so the error > > return path only occurs when rval is negative. > > > > Addresses-Coverity: ("Logically dead code") > > Fixes: 287980e49ffc ("remove lots of IS_ERR_VALUE abuses") > > Signed-off-by: Colin Ian King <colin.king@canonical.com> > > --- > > drivers/media/i2c/adp1653.c | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/drivers/media/i2c/adp1653.c b/drivers/media/i2c/adp1653.c > > index 522a0b10e415..1a4878385394 100644 > > --- a/drivers/media/i2c/adp1653.c > > +++ b/drivers/media/i2c/adp1653.c > > @@ -170,7 +170,7 @@ static int adp1653_set_ctrl(struct v4l2_ctrl *ctrl) > > int rval; > > > > rval = adp1653_get_fault(flash); > > - if (rval) > > + if (rval < 0) > > return rval; > > This is good, but all the other callers need to fixed as well: > > > 140 static int adp1653_get_ctrl(struct v4l2_ctrl *ctrl) > 141 { > 142 struct adp1653_flash *flash = > 143 container_of(ctrl->handler, struct adp1653_flash, ctrls); > 144 int rval; > 145 > 146 rval = adp1653_get_fault(flash); > 147 if (rval) > 148 return rval; > 149 > 150 ctrl->cur.val = 0; > 151 > 152 if (flash->fault & ADP1653_REG_FAULT_FLT_SCP) > ^^^^^^^^^^^^ > flash->fault is the equivalent of "rval" for non-negative returns so > this condition can never be true. We should never be returning these > weird firmware ADP1653_REG_FAULT_FLT_SCP fault codes to the v4l2 layers. I think this could be fixed and cleaned up by always retuning zero on success, and checking for flash->faults while holding the mutex in adp1653_init_device. I could fix that, too, just let me know... -- Regards, Sakari Ailus
diff --git a/drivers/media/i2c/adp1653.c b/drivers/media/i2c/adp1653.c index 522a0b10e415..1a4878385394 100644 --- a/drivers/media/i2c/adp1653.c +++ b/drivers/media/i2c/adp1653.c @@ -170,7 +170,7 @@ static int adp1653_set_ctrl(struct v4l2_ctrl *ctrl) int rval; rval = adp1653_get_fault(flash); - if (rval) + if (rval < 0) return rval; if ((rval & (ADP1653_REG_FAULT_FLT_SCP | ADP1653_REG_FAULT_FLT_OT |