aic94xx: maybe uninitialized variable in asd_process_ctrl_a_user

aic94xx: maybe uninitialized variable in asd_process_ctrl_a_user

[Filipe Brandenburger]

Hi James,

While building a recent kernel with -Werror I found this warning:

drivers/scsi/aic94xx/aic94xx_sds.c: In function 'asd_read_flash':
drivers/scsi/aic94xx/aic94xx_sds.c:597:21: error: 'offs' may be used
uninitialized in this function [-Werror=maybe-uninitialized]
drivers/scsi/aic94xx/aic94xx_sds.c:985:6: note: 'offs' was declared here

This looks like a valid complaint from the compiler, since in
asd_process_ctrl_a_user if the call to asd_find_flash_de fails (and
returns -ENOENT) then offs will not be set, but that will not prevent
the variable to be later passed to the call to asd_read_flash_seg
later in that same function.

Would you please have a look at it? Let me know if there's a more
appropriate way to report these issues (e.g. bug tracker.)

Thanks,
Filipe

Re: aic94xx: maybe uninitialized variable in asd_process_ctrl_a_user

[Paul Bolle]

On Thu, 2014-04-10 at 22:13 -0700, Filipe Brandenburger wrote:
> While building a recent kernel with -Werror I found this warning:
> 
> drivers/scsi/aic94xx/aic94xx_sds.c: In function 'asd_read_flash':
> drivers/scsi/aic94xx/aic94xx_sds.c:597:21: error: 'offs' may be used
> uninitialized in this function [-Werror=maybe-uninitialized]
> drivers/scsi/aic94xx/aic94xx_sds.c:985:6: note: 'offs' was declared here

This warning is actually rather old.

> This looks like a valid complaint from the compiler, since in
> asd_process_ctrl_a_user if the call to asd_find_flash_de fails (and
> returns -ENOENT) then offs will not be set, but that will not prevent
> the variable to be later passed to the call to asd_read_flash_seg
> later in that same function.
> 
> Would you please have a look at it? Let me know if there's a more
> appropriate way to report these issues (e.g. bug tracker.)

I tried a few times to fix this warning.

In the end I just asked Fedora to disable aic94xx in their kernel builds
(which they did for Rawhide, their development branch). See
https://lists.fedoraproject.org/pipermail/kernel/2014-January/004759.html for all the boring details.


Paul Bolle