[gentoo-dev] Re: Bleeding edge hardened-sources: move PaX markings from ELF to Extended Attributes

[Duncan]

Anthony G. Basile posted on Thu, 01 Dec 2011 11:08:37 -0500 as excerpted:

> I've been doing some experimental work with PaX enabled kernels

> The disadvantage is that xattrs is not supported on all filesystems

> b) Kernels 3.0 and above support xattrs in tmpfs, squashfs and other
> filesystems.

[I debated sending this offlist as my interest isn't entirely on-topic, 
but as I wrote it up, it became apparent that the question itself isn't 
as off-topic as I thought, so on-list it stayed.]


TL;DR:  reiserfs (v3), for both caps and XT_PAX ??


Longer:  Does reiserfs (v3) support xattrs and thus, presumably caps and 
XT_PAX?  Kernel reiserfs options suggest yes, but everything I've read 
elsewhere (including gentoo-dev caps project discussions) seems to 
indicate no.  Is the "no" simply outdated, since reiserfs xattrs support 
was added relatively late in the game, or is it still correct and I have 
the purpose of those kernel options all wrong, or ???

If both reiserfs and tmpfs (my $PORTAGE_TMPDIR) support xattrs, both caps 
and XT_PAX should be good to go, correct?


Ignorable background:  I've been running reiserfs since early in the 
kernel 2.4 era, before switching to gentoo, and have had quite a good 
experience on it since it got ordered journals by default (before that, 
let's not talk about), despite a period with bad RAM that was hard-
crashing the system frequently, no UPS, and apparently missing barriers 
until quite recently.  I've even been stable when others had problems 
with ext3 due to its writeback-by-default period.  I intend to eventually 
switch to btrfs but there's still more kernel churn there than I'm 
comfortable with, especially running live-git kernels as I normally do, 
and of course, it's still lacking a proper fsck (tho arguably reiserfs' 
fsck support has always been "interesting" as well, and that's not such a 
big deal given the backups I already keep based on pre-ordered era 
experience).

My interest is therefore in whether USE=caps does people on reiserfs any 
good or not, but the same concerns would appear to apply to XT_PAX on 
reiserfs, as well.

-- 
Duncan - List replies preferred.   No HTML msgs.
"Every nonfree program has a lord, a master --
and if you use the program, he is your master."  Richard Stallman