Messages in this thread | | | Date | Fri, 31 Jul 2020 11:38:56 +0300 | From | Andy Shevchenko <> | Subject | Re: [PATCH v2] staging: atomisp: move null check to earlier point |
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On Fri, Jul 31, 2020 at 01:17:38AM +0300, Cengiz Can wrote: > `find_gmin_subdev` function that returns a pointer to `struct
func() are referred with name followed by parentheses.
> 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. ie:
'. ie:' -> ', i.e.:'
> ```
Instead just shift right by two spaces.
> /* Acquired here --------v */ > struct gmin_subdev *gs = find_gmin_subdev(subdev); > > /* v------Dereferenced here */ > if (gs->v2p8_gpio >= 0) { > ... > }
> ```
Drop this as per above comment.
> To avoid the issue, null check has been moved to an earlier point > and return semantics has been changed to reflect this exception.
> Please do note that this change introduces a new return value to > `gmin_v2p8_ctrl`.
This rather should explain better the semantics change, e.g. "Now the function() refuses to take NULL argument and returns an error. We also WARN() for sake of the debugging."
> [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.
This has to go after cutter '---' line below.
> Caught-by: Coverity Static Analyzer CID 1465536
Reported-by:
And as discussed previously, Suggested-by: Mauro ...
> Signed-off-by: Cengiz Can <cengiz@kernel.wtf>
The code looks good enough (WARN() will probably go away when driver gains better quality).
-- With Best Regards, Andy Shevchenko
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