Re: [kmemcheck] WARNING: kmemcheck: Caught 32-bit read from uninitialized memory, in hid_output_report

[Jiri Kosina <jkosina@suse.cz>]

On Sun, 30 Aug 2009, Jeff Smith wrote:

> A patch follows. It corrects a typo in the comment, changes the function 
> name "implement" to "set_into_le_bitstream", changes the parameter name 
> "n" to "bitfield_size", printk's unsigned using %u not %d, and only does 
> a 32-bit read-modify-write when a 64-bit one is not necessary.
> 
> A patch that writes only the bytes that need to be changed, rather than 
> 32 or 64-bit quantities that potentially access irrelevant memory 
> locations -- and that therefore require more complicated verification 
> logic -- would be a better approach. However, as we are at -rc8 already 
> and I don't fully understand the structures that are being changed, or 
> the reasons the code is as it is, I didn't feel confident about 
> presenting such a restructuring here.

Hi Jeff,

thanks for the patch, it looks correct on a quick glance. I would however 
prefer the other approach you proposed. 

We probably don't have to be nervous about being currently at -rc8, as 
this will probably be fixed only in .32-rc1 anyway (as the unitialized 
data is not used in any way, and therefore it doesn't require emergency 
fix just to silence the kmemcheck warning).

Thanks,

-- 
Jiri Kosina
SUSE Labs