Subject: Re: commoning up code that changes uids and gids
To: David Laight <firstname.lastname@example.org>
From: Jaromir Dolecek <email@example.com>
Date: 03/04/2003 09:57:36
While commoditation like this is in principle good thing, I don't
think it's wise to do if you are not 200% sure you are right.
E.g. I'm not sure if this in sys_setregid():
> + if (rgid == -1)
> + rgid = p->p_cred->p_rgid;
> + svgid = rgid == p->p_cred->p_rgid ? -1 : egid;
is bug or uncommented code shortcut or harmless completely.
It is VERY bad to change such sensitive code just for change's
> This also stops the 'compat' functions getting out of step with
> any future changes.
Did you confirm the semantics for compat code matches
previous state? E.g. linux_misc.c/linux_misc_notalpha.c has
* Note: These checks are a little different than the NetBSD
* setreuid(2) call performs. This precisely follows the
* behavior of the Linux kernel.
AFAICS most of other compat code uses some variant of setresuid() playing
with saved IDs; adding compat_setresuid() function to compat/common/
and make compat code use that, should be sufficient WRT code sharing.
Jaromir Dolecek <jdolecek@NetBSD.org> http://www.NetBSD.org/
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