On Wed, Apr 18, 2012 at 12:16 AM, David Miller <davem@xxxxxxxxxxxxx> wrote: > From: "Carlos O'Donell" <carlos@xxxxxxxxxxxxxxxx> > Date: Wed, 18 Apr 2012 00:08:47 -0400 > >> I don't clearly understand your position here, and perhaps that's my >> own ignorance, but could you please clarify, with examples, exactly >> why the change is not acceptable? > > My position is that since millions upon millions of Linux systems, in > fact every single Linux system, exists right now with the current > behavior we are not helping application writers at all by changing > behavior now after it's been this way for nearly 20 years. > > Because if an application writer wants his code to work on systems > that actually exist he has to accomodate the non-NULL termination > situation if he wants to inspect or print out an AF_UNIX path. > > Because every system in existence right now allows the non-NULL > terminated AF_UNIX paths, therefore it's possible on every system > in existence right now. > > Catch my drift? > > The very thing the patch claims to help, it doesn't. We install this > kernel patch now and then tell application writers that they can just > assume all AF_UNIX paths are NULL terminated when they want to print > it out, because such code will not actually be guarenteed to work on > all deployed Linux machines out there. > > You cannot just ignore 20 years of precedence and say "oh let's change > this in the kernel now, and that way application writers don't have to > worry about that lack of NULL termination any more." It simply > doesn't work like that. > > All of this talk about whether applications actually create non-NULL > terminated AF_UNIX paths don't even factor into the conversation. > > So the value proposition for this patch simply does not exist. Thank you, this is the kind of position statement I can point to if I ever get asked about this again. In summary your opinion is that the API has and always will allow up to 108 chars to be used in sun_path? In which case I will talk to the Austin group to get a good example added to POSIX showing safe usage. Cheers, Carlos. -- To unsubscribe from this list: send the line "unsubscribe linux-api" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
