Messages in this thread | | | From | Cengiz Can <> | Date | Thu, 06 Aug 2020 21:34:22 +0300 | Subject | Re: [PATCH v6] staging: atomisp: move null check to earlier point |
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Hello Andy,
Can I get some feedback on v6 please?
I hope it suits your standards this time.
Thank you
On August 2, 2020 01:02:22 Cengiz Can <cengiz@kernel.wtf> wrote:
> `find_gmin_subdev()` that returns a pointer to `struct > gmin_subdev` can return NULL. > > In `gmin_v2p8_ctrl()` there's a call to this function but the > possibility of a NULL was not checked before its being dereferenced, > i.e.: > > /* Acquired here --------v */ > struct gmin_subdev *gs = find_gmin_subdev(subdev); > > /* v------Dereferenced here */ > if (gs->v2p8_gpio >= 0) { > ... > } > > With this change we're null checking `find_gmin_subdev()` result > and we return an error if that's the case. We also WARN() > for the sake of debugging. > > Signed-off-by: Cengiz Can <cengiz@kernel.wtf> > Reported-by: Coverity Static Analyzer CID 1465536 > Suggested-by: Mauro Carvalho Chehab <mchehab@kernel.org> > --- > > Please do note that this change introduces a new return value to > `gmin_v2p8_ctrl()`. > > [NEW] - raise a WARN and return -ENODEV if there are no subdevices. > - return result of `gpio_request` or `gpio_direction_output`. > - return 0 if GPIO is ON. > - return results of `regulator_enable` or `regulator_disable`. > - according to PMIC type, return result of `axp_regulator_set` > or `gmin_i2c_write`. > - return -EINVAL if unknown PMIC type. > > Patch Changelog: > v4: Fix minor typo in commit message > v5: Remove typo from email subject > v6: Remove duplicate Signed-off-by tag > > drivers/staging/media/atomisp/pci/atomisp_gmin_platform.c | 5 ++++- > 1 file changed, 4 insertions(+), 1 deletion(-) > > diff --git a/drivers/staging/media/atomisp/pci/atomisp_gmin_platform.c > b/drivers/staging/media/atomisp/pci/atomisp_gmin_platform.c > index 0df46a1af5f0..1ad0246764a6 100644 > --- a/drivers/staging/media/atomisp/pci/atomisp_gmin_platform.c > +++ b/drivers/staging/media/atomisp/pci/atomisp_gmin_platform.c > @@ -871,6 +871,9 @@ static int gmin_v2p8_ctrl(struct v4l2_subdev *subdev, > int on) > int ret; > int value; > > + if (WARN_ON(!gs)) > + return -ENODEV; > + > if (gs->v2p8_gpio >= 0) { > pr_info("atomisp_gmin_platform: 2.8v power on GPIO %d\n", > gs->v2p8_gpio); > @@ -881,7 +884,7 @@ static int gmin_v2p8_ctrl(struct v4l2_subdev *subdev, > int on) > pr_err("V2P8 GPIO initialization failed\n"); > } > > - if (!gs || gs->v2p8_on == on) > + if (gs->v2p8_on == on) > return 0; > gs->v2p8_on = on; > > -- > 2.27.0
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