cvs commit: src/sys/compat/linux linux_misc.c src/sys/kernkern_time.c src/sys/sys systm.h

[Maxim Sobolev]

John Baldwin wrote:
> On Monday 31 January 2005 04:01 pm, Maxim Sobolev wrote:
> 
>>John Baldwin wrote:
>>
>>>On Tuesday 25 January 2005 04:28 pm, Maxim Sobolev wrote:
>>>
>>>>sobomax     2005-01-25 21:28:28 UTC
>>>>
>>>> FreeBSD src repository
>>>>
>>>> Modified files:
>>>>   sys/compat/linux     linux_misc.c
>>>>   sys/kern             kern_time.c
>>>>   sys/sys              systm.h
>>>> Log:
>>>> Split out kernel side of {get,set}itimer(2) into two parts: the first
>>>>that pops data from the userland and pushes results back and the second
>>>>which does actual processing. Use the latter to eliminate stackgap in the
>>>>linux wrappers of those syscalls.
>>>>
>>>> MFC after:      2 weeks
>>>
>>>Hmm, I already implemented kern_[sg]etitimer() locally and fixed all the
>>>ABIs, not just Linux to use them.  I haven't had time to test the patches
>>>though. Would you be interested in them?
>>
>>I would be happy to, but I don't have any platforms other than i386
>>(which is why I have not touched other arches). Therefore I am probably
>>a wrong person to do the testing. Is your approach different/better than
>>mine? I'd be happy to do the merge if so.
> 
> 
> I've already merged.  It's mostly the same except I put the logic to fall back 
> to kern_getitimer() when there is no new itimerval in kern_setitimer() rather 
> than duplicating that in all the ABIs.

Well, I had considered such approach, but rejected it because actually 
it doesn't win you much since you have to add some logic to avoid 
copyin() and submit NULL instead of &aitv to signal kern_setitimer() 
that it has to call kern_getitimer() into each ABI instead. As to my 
taste such obfuscation (which is duplicated among all ABIs) isn't worth 
it. At the same time, linecount wise it is probably the same amount of 
duplication anyway.

-Maxim