Messages in this thread | | | Date | Mon, 25 May 2015 13:50:47 +0200 | From | Nicholas Mc Guire <> | Subject | Re: [PATCH] cgroup: add explicit cast and comment for return type conversion |
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On Mon, 25 May 2015, Tejun Heo wrote:
> Hello, Nicholas. > > On Mon, May 25, 2015 at 07:57:42AM +0200, Nicholas Mc Guire wrote: > > nop not downward but signed/unsigned if it were down it would not be > > a problem but signed/unsigned can be - for those cases where it can't > > be fixed up by changing the declarations or return variable types > > explicit cast might make sense - as noted in the patch Im not sure either > > if this form of cleanups is helpful. > > > > In the kernel core there are about 400 signed/unsigned implicit > > conversions (about 3k in the entire kernel) which is what Im trying to > > remove or if that is not possible in a resonable way mark as false positive. > > I still don't get it. What does this buy us actually? If we continue > to do this, people would just learn to add explicit cast when doing > sign conversions. We just converge to a different behavior without > actually gaining any protection. What's the benefit of doing this? > that would be no benefit of course - the goal is not to simply put casts in but to use casts as last resort if type cleanups are not doable or if the type missmatch is intended - the cast then should document that it is intentional and comments explain why it is justified. If that were the result of type cleanup I think it would benefit the kernel code as I suspect that quite a few of the type missmatches simply happened.
thx! hofrat
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