[lkml]   [1999]   [Jan]   [8]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
SubjectRe: UID width
On Tue, Jan 05, 1999 at 12:05:48AM +0000, H. Peter Anvin wrote:

> This is an FAQ. This is part of Linux' Minix legacy, and will be
> fixed in the 2.3 kernel series. Binary backwards compatibility
> will be provided with libc6 binaries, but not libc5 or earlier if
> uid/gid >= 65535 are in use.

Actually... >= 65534 because '-1' has a special meaning for some
system calls (eg. setreuid).

btw... I've made partial patches for 32-bit uid_t support (I know
someone else has too, against 2.0.36 or thereabouts) and this
introduces a whole bunch of new system calls, even for things like
fcntl (think SET_OWN).

At some point in the future we might also want 32-bit dev_t and
32-bit pid_t so its probably worth trying to do them all at once,
that way we don't end up with 15 different flavours of the same
system calls (think about stat et al and all the combinations of
short/long system calls... yuck).

One problem I have in doing this, is some of the glibc IPC structures
assume 16-bit pid_t -- which IMO is damned silly.

Anyhow, if anyone wants to lend a hand here, it would be most
appreciated -- please contact me off the list. There are library
issues that also need to be resolved, and various user-land tools
need fixing so as not to introduce security problems.

Oh, and please don't tell me about not every needing more than a
16-bit pid_t -- mingo has already posted patches (twice) to make this
possible, even though its presently not terribly practical...


To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to
Please read the FAQ at

 \ /
  Last update: 2005-03-22 13:49    [W:0.066 / U:0.816 seconds]
©2003-2018 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site