[patch 0/4] /proc/kmsg permissions, take four

[Zack Weinberg <zackw@panix.com>]

Here's yet another revision of the /proc/kmsg permissions patch
series.  To recap, the point is to allow klogd to drop privileges
and continue reading from /proc/kmsg (currently, even if klogd has a
legitimately opened fd on /proc/kmsg, it cannot read from it unless
it has CAP_SYS_ADMIN asserted).  SELinux's pickier and finer-grained
privilege rules for /proc/kmsg are unchanged.

There are two significant changes from the previous revision.  First,
in keeping with the recommended style, I have eliminated the
security_syslog_or_fail() macro.  Instead there is a static array mapping
KLOG_* opcodes to LSM_KLOG_* privilege classes.  This requires slightly
different coding in the security hooks but I think it's clearer overall.
Second, I've incorporated Vincent Legoll's kerneldoc comment for sys_syslog
(nee do_syslog) with some wording improvements and expansion to cover the
klog_* functions introduced part-way through the patch.  I don't think
proc/kmsg.c needs kerneldoc, it's very simple after this patch series.

I've been through Documentation/CodingStyle and satisfied myself that
everything is now in the proper mode.  I don't suppose anyone has comments
on the *content* of the changes...?

zw