Re: Negative Reserved Return values (was Re: Proposal "LUID&Sess...)

From: Linda Walsh (law@sgi.com)
Date: Wed Apr 19 2000 - 15:05:52 EST


Borislav Deianov wrote:
> PIDs are signed int and currently limited to 0x8000, so they don't
> have a problem.

---
	So if we went to a 32-bit pid at some point in the future, that would
likely be limited as well.

> > UIDs are unsigned int. The only calls that return uid_t (getuid and > geteuid) cannot fail, so there's no problem here either. --- Can't currently fail. I dunno about future -- can't think of a scenario, but my imagination is finite.

> What is "etc" above? We can be careful when adding new system calls so > we don't run into this in the future. --- times should added to the list of 'never failing functions' 'dup' is treated special -- shouldn't ever be a problem (by my finite imagination again :-)) 'getgroups' special same way, again shouldn't be a problem

There are a few others where return value is used to indicate a 'positive' value (items returned) or a -1 on failure -- they would all fall into the 'read' class of return values and so aren't problems.

So it would appear, really, that only disallowed UID value would be 0xffff[ffff]. So in the glib files, they need to make sure not to disallow UID's >0x8fff ffff.

Ok dok.

Copacetic to me... -l

-- Linda A Walsh | Trust Technology, Core Linux, SGI law@sgi.com | Voice: (650) 933-5338

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