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Well, I suppose I should be happy that mksh is actually used…

  • [tg] Correct shf buffer I/O routines to avoid a memory corruption bug discovered by Waldemar Brodkorb and other bad effects
  • [tg] Fix NULL pointer dereference during iteration loop when checking for alias recursion; discovered by Michal Hlavinka

That’s OpenADK (Waldemar’s fork of FreeWRT, which is Waldemar’s fork of OpenWrt), and Red Hat Enterprise Linux, respectively. Popcon in Debian and its derivates is also pleasant.

I could use some help bugfixing this though:

	(sleep 3; exit 12) &
	bgprocpid=$!
	sleep 6
	# background process is done by now
	wait $bgprocpid
	# POSIX mandates that, since $! was asked
	# for, wait is to reply its errorlevel

Somehow, JF_KNOWN is never set – and I can’t debug this with gdb(1).

(There’s also a dashism in some *buntu start scripts that does pretty much the same except it uses “wait %1” there. In fact it doesn’t even seem to use $! – no idea whether we can support that at all in a POSIX shell – which dash clearly isn’t… – without keeping track of background processes forever.)

I’ve got some interesting results using r1.1 of an example test programme (r1.2 got cleaned up and more output) on various systems, regarding ASLR. The 1.1 revision tests everything mksh R40+ will use (except there will probably no larger than page sized allocations) for its LCG PRNG. On OpenBSD (MirBSD, ÆrieBSD) malloc(3) uses in fact mmap(2), which is randomised. (Though -pie doesn’t yet work as it’s supposed to.) Some OSes are better than others… but look for yourself. (Read on to continue, not part of the RSS for size reasons. This wlog entry may be updated – with bumped date – unperiodically.)

MirBSD-current/i386

tg@blau:~ $ mgcc -static x.c
x.c:0: note: someone does not honour COPTS correctly, passed 0 times
x.c: In function `foo':
x.c:27: warning: function returns address of local variable
tg@blau:~ $ ./a.out
0xa9332000 0xaba65000 0xa0ae7000 0xcfbed990 0xcfbed994
tg@blau:~ $ ./a.out
0xa91b4000 0xa02b1000 0xa1602000 0xcfbf8680 0xcfbf8684
tg@blau:~ $ ./a.out
0x9f731000 0x9cb2a000 0xa94ca000 0xcfbf5840 0xcfbf5844
tg@blau:~ $ ./a.out
0x9c2af000 0xa6a0b000 0xa4ce1000 0xcfbefac0 0xcfbefac4
tg@blau:~ $ ./a.out
0xa3b61000 0xa96de000 0xa96df000 0xcfbedcc0 0xcfbedcc4

Debian Ätsch/i386

tg@frozenfish:~ $ gcc -static x.c
x.c: In function ‘foo’:
x.c:27: warning: function returns address of local variable
x.c: In function ‘bar’:
x.c:33: warning: function returns address of local variable
tg@frozenfish:~ $ ./a.out
0x80b2a20 0x80b2a30 0xb7745008 0xbf985ce0 0xbf985cd4
tg@frozenfish:~ $ ./a.out
0x80b2a20 0x80b2a30 0xb7726008 0xbfb911b0 0xbfb911a4
tg@frozenfish:~ $ ./a.out
0x80b2a20 0x80b2a30 0xb7784008 0xbf83d040 0xbf83d034
tg@frozenfish:~ $ ./a.out
0x80b2a20 0x80b2a30 0xb77e8008 0xbfc0f840 0xbfc0f834

tg@frozenfish:~ $ sid
I: [sid chroot] Running command: “mksh -l”
tg@frozenfish:~ $ gcc -static x.c
x.c: In function ‘foo’:
x.c:27: warning: function returns address of local variable
x.c: In function ‘bar’:
x.c:33: warning: function returns address of local variable
tg@frozenfish:~ $ ./a.out
0x80c86a8 0x80c86b8 0xb77c3008 0xbfaa1900 0xbfaa18f4
tg@frozenfish:~ $ ./a.out
0x80c86a8 0x80c86b8 0xb77d2008 0xbfcc0260 0xbfcc0254
tg@frozenfish:~ $ ./a.out
0x80c86a8 0x80c86b8 0xb77c1008 0xbfbe2120 0xbfbe2114

uname: Linux frozenfish 2.6.18-6-686 #1 SMP Fri Feb 19 23:40:03 UTC 2010 i686 GNU/Linux

Solaris 8/sparc64

tg@stinky:~ $ gcc -static x.c
x.c: In function `foo':
x.c:27: warning: function returns address of local variable
tg@stinky:~ $ ./a.out
595f0 59bf0 59d00 ffbefbb4 ffbefb5c
tg@stinky:~ $ ./a.out
595f0 59bf0 59d00 ffbefbb4 ffbefb5c
tg@stinky:~ $ ./a.out
595f0 59bf0 59d00 ffbefbb4 ffbefb5c
tg@stinky:~ $ gcc x.c
x.c: In function `foo':
x.c:27: warning: function returns address of local variable
tg@stinky:~ $ ./a.out
20950 20f50 21060 ffbefb3c ffbefae4
tg@stinky:~ $ ./a.out
20950 20f50 21060 ffbefb3c ffbefae4

MidnightBSD/amd64

mirabilos@stargazer:~ $ gcc -static x.c
x.c: In function 'foo':
x.c:27: warning: function returns address of local variable
x.c: In function 'bar':
x.c:33: warning: function returns address of local variable
mirabilos@stargazer:~ $ ./a.out
0x800603080 0x800605040 0x800700000 0x7fffffffe62c 0x7fffffffe62c
mirabilos@stargazer:~ $ ./a.out
0x800603080 0x800605040 0x800700000 0x7fffffffe63c 0x7fffffffe63c
mirabilos@stargazer:~ $ ./a.out
0x800603080 0x800605040 0x800700000 0x7fffffffe62c 0x7fffffffe62c

uname: MidnightBSD stargazer.midnightbsd.org 0.3-CURRENT MidnightBSD 0.3-CURRENT #1: Thu May 27 22:13:45 EDT 2010 root@stargazer.midnightbsd.org:/usr/obj/usr/src/sys/GENERIC amd64

Debian sid/mipsel

(QEMU, thanks to Aurélien! Debian unstable from approx. Jan 2010)

root@debian-mipsel:~ # gcc-4.4 -static x.c
x.c: In function 'foo':
x.c:27: warning: function returns address of local variable
x.c: In function 'bar':
x.c:33: warning: function returns address of local variable
root@debian-mipsel:~ # ./a.out
0x4aa740 0x4aa750 0x2aaa8008 0x7fa417e8 0x7fa417d8
root@debian-mipsel:~ # ./a.out
0x4aa740 0x4aa750 0x2aaa8008 0x7fc67708 0x7fc676f8
root@debian-mipsel:~ # ./a.out
0x4aa740 0x4aa750 0x2aaa8008 0x7fb68238 0x7fb68228
root@debian-mipsel:~ # ./a.out
0x4aa740 0x4aa750 0x2aaa8008 0x7fc586c8 0x7fc586b8

uname: Linux debian-mipsel 2.6.32-trunk-4kc-malta #1 Mon Jan 11 03:45:08 UTC 2010 mips GNU/Linux

Gentoo GNU/Linux on amd64

gcc-4.4.4, glibc-2.11.2-r0, 2.6.35-rc4 x86_64

0x20cc010 0x20cc030 0x7fef0c497010 0x7fff32148fec 0x7fff32148fec
 0xa35010  0xa35030 0x7f575d0e4010 0x7fff0dd7220c 0x7fff0dd7220c
0x1f90010 0x1f90030 0x7f8657107010 0x7fff6116813c 0x7fff6116813c
 0x9dd010  0x9dd030 0x7f1eab0a6010 0x7fff3dcc638c 0x7fff3dcc638c

Conclusion

Not everyone does ASLR… but there’s enough variety (and with eglibc’s AT_RANDOM even proper entropy) inside for our purposes. On OpenBSD and MirBSD, we’ll still use KERN_ARND as it’s extremely cheap entropy (code paths checked on both) but not for every call of $RANDOM. On things like Debian/m68k mksh(1) ought to have gained a possibly noticeable speed-up.

Back home

11.07.2010 by tg@
Tags: bug debian event geocache mksh news release snapshot

Bordeaux was very nice (and towards the end much cooler… it’s actually hotter here at more than 50½° north – too warm to think, or do anything) but the LSM/RMLL was very french. They’ll be in Straßburg and Lüttich the next two years so we can probably be expected to attend. I don’t think I can eat duck (which, in south-west france, is a vegetable) or like all that classic french multi-course food so much, but I had enough Couscous Merguez and Thé à la menthe fraîche… and similar good stuff. Many people spoke English and actually asked me whether I do (probably they couldn’t bear me trying to spea^W^W^Wbutchering the language of the Grande Nation) and in general were a friendly bunch. I did see some people with machine guns in the city on the last day, though. No idea what/why… didn’t dare asking ☻

Just another reason to boycott flying: Mario Lang (one of the speakers) was apparently held on the airport and treated as a terrorist due to his Braille line… they thought it was a bomb or somesuch thing.

Read on for more…

Travelling with the Thalys and TGV was nice (but I loathe the Métro parisienne… they should build a ring train like the Berlin S-Bahn and just put another stop before Paris Nord and Montparnasse for people who just want to switch trains to take the ring train to the other line). And I want air conditioned trams in Germany too!

I met Uriel (invited him for some food and talked lengthy with him and some 9grid guy), XTaran (who was rather busy organising things), and a number of other people. Did some PGP keysigning as well. There’s now an experimental MirOS presence at Launchpad, not sure what exactly we’re going to do with it but, as Canonical does not care (as Jonathan said in his talk – great slides, by the way, really impressive), there’s no harm in having it. Some Perl guy from America (USA… just to make sure ☺) wanted a photograph of me with a sign “I love CVS” just so people back at home would believe him he’s met such a person *grins* of course I plugged in a little advertising but cvs(GNU) is honestly good. The forge hacking session was a little under-visited (but still a success in terms of getting more communication and maybe collaboration underways, especially thinking of common interfaces, DC, semantic web, OSLC-CM) and since the room was (in contrast to my hotel room and the trams!) not air conditioned we didn’t get much hacking done. The Debian booth was about 40% of one FOSDEM style table wide… and subsequently crowded. There were more people (of course, I was trying to get mksh into Haikuports, Mandriva, and other things; talked about KDE 3.5.11 (Trinity), Qt 3 vs Qt 4, and kwalletcli, and in general to a not-so-usual bunch of suspects – like I said, LSM/RMLL really is pretty french-only).

It is too hot, but I still committed src/etc/rc,v version 1.110 which you want to upgrade your /etc/rc to before upgrading mksh(1) in MirBSD. (All in the name of better performance on platforms such as Debian/m68k and not raiding Linux’ inferior RNG… but it does simplify things.)

I could probably write more but at the moment just want to lie down and die until it gets cooler… even the rain didn’t help. My feet hurt (Montparnasse-Bienvenue didn’t help) too.

The current version of mksh had use of arc4random(3) removed, including “set -o arc4random”, to speed it up (on some architectures, a lot) – this will break some existing scripts (such as /etc/rc *cough* on MirBSD…). Hence I decided to publish the next version of mksh(1) as R40 based upon current development, and defer plans for associative arrays (and multidimensional arrays) for mksh R41. There’s also already the change to Build.sh arguments, so this suits me quite fine.

(Read: if running MirBSD, don’t upgrade mksh at the moment.) There will be a new MirBSD snapshot once this is fixed, maybe a few more changes to the shell for better POSuX compliance, and the recently mentioned patent on LFNs (long filename) in FAT will be taken into account with a patch to msdosfs.

I’ll travel to LSM/RMLL 2010, the Libre Software Meeting (Rencontres Mondiales du Logiciel Libre) tomorrow until the weekend, to hack some on FusionForge (this is worktime for me), visit XTaran, Uriel, and maybe a couple of other “usual people”.

Thundersday, between 10:00 UTC and 12:00 UTC, eurynome will be shut down by gecko2@ due to power supply maintenance on the host system data centre.

We have a new mirror in the Americas, thanks a lot to Mike 'Fuzzy' Partin! Benny will mention it on the webpages once it’s working.

odem is dead

17.06.2010 by tg@

My laptop odem has a somewhat split personality… half of it ended up in the waste bin, the other half will probably end up being sold under price to someone who may then sell the parts separately from each other (I’m not in the mood to do packaging and shipping). Salvaged parts: some PC133 SO-SDRAM (probably 512 and 256 MiB), an Athlon XP 1400+ CPU, an Acer Aspire 1300XC(?) BIOS, floppy drive, DVD-ROM/CD-RW drive, complete display (panel, inverter and chassis), CMOS battery, a lot of screws, the fan, some cables, the upper half of the chassis, the keyboard, and probably other things.

In case someone noticed: the mksh web page now looks nicer, and it’s even mentioned in some forum thread as the “popular” shell ☺

Mojito tastes good… we had a soldering social evening at $orkplace followed by an ad-hōc visit to the cocktail bar due to missing the tram (caught the next one). Summer’s gone again though… rain really is imminent now ☹

This wlog entry is presented you by gecko2@’s nagging… we’re really working though, so don’t expect many… I’m even doing the Debian stuff only at ork at the moment.

SPARCstation 20 (75 MHz)

09.06.2010 by tg@
Tags: debian rant

Wenn Du denkst, MirBSD wäre langsam und sein Installer in irgendeiner Art und Weise doof, dann installiere mal Debian (etch, neuere Versionen können nur noch sun4u und sun4v, kein sun4m mehr) auf einer SPARCstation 20.

Lahm wie Sau, das Teil. Und der Installer ist schwarz auf weiß – was nicht so schlimm wäre, wenn der Cursor (und die dialog-Markierungen) nicht ebenfalls schwarz auf weiß wären…

Ich bin ja mal gespannt, ob das durchläuft.

In response to a planet.d.o series (mentioned in #grml on IRC) of postings: In a sensible shell, Esc+# not only pushes it back but also re-enables the command. Try it out: l s Esc # Cursor-Up Esc #

tg@blau:~ $ #ls
tg@blau:~ $ ls

The command sticks in the history, and is not immediately shown in the next interactive input line, which I consider a plus in most use cases. Anyway, try mksh (just a-g i it), there are a lot of goodies. I found out about Ctrl-O only a year or so ago myself…

I wonder why schizo didn’t write about how to do it in posh tho ☺

Hello, World!

22.05.2010 by tg@
Tags: mksh

Just a random status update: I’ve been too busy with the dayjob, now ill for about two weeks already. There have been some minor mksh fixes but I’d still like to catch up on the Austin ML postings before releasing R39d; Android discussion is live. The base system has some issues found, but I will take a while (no hacking mood, even when not ill).

Scan this! and Google’s playable logo is just weird (at least no sound in Opera) but at least it’s not Fläsh. I played it but there’s no second level. Tonnerre likes «Forth op de Fiets» (as a pun on Ruby on Rails), which lets me remember the Forth Glockenspiel.

Sorry for the lack of updates, but MirBSD is still pretty much a fun project, and Benny is working on his Doctor thesis too.

FWIW: Patents on software are evil and times are worsening. I suppose, if we’ll be able to continue MirBSD at all, I need to disable FAT LFN support. Sucks.

The bsiegert-cfgfile branch of the MirPorts package tools is coming along nicely. Today I committed a patch to info/perform.c that puts its logic from the head on its feet, making the function more readable and, incidentally, getting rid of two gotos. The header of the information has become a little more informative. Watch:

% pkg_info foo
pkg_info(foo): cannot find package 'foo' installed or in a file!

% pkg_info tiff | head -4
Information for tiff-3.7.4-1 (installed):

Comment:
library routines for working with TIFF images

Something new that I got working is support for giving the name of an uninstalled package in a repository mentioned in the new /etc/pkgtools/pkgtools.conf file. This works for both local and remote repos:

% pkg_info tiff-cxx | head -4
Information for /usr/ports/Packages/tiff-cxx-3.7.4-1.cgz:

Comment:
C++ API for working with TIFF images

% pkg_info mc | head -4
>>> ftp -o - http://www.mirbsd.org/MirOS/Pkgs/current/i386//mc-4.6.1-16.cgz
Information for /var/folders/Xk/XkVpSyd8F0WZnoK9NwgsWU+++TI/-Tmp-//instmp.4OV2INPVOK:

Comment:
free Norton Commander clone with many useful features

Actually, in the last case, the output could be improved some more :). You can also give it a package specification such as "tiff->=3.0". If more than one package matches the specification given, then a menu is displayed from which you choose one. This happens, for instance, if you have an older version built locally and a newer version of the same package in a remote repo, or if several flavours of the package are available.

The changes are not in the HEAD branch yet, I will merge them when I consider it "done".

Some things are ugly.

Waldi’s suggestion fails.

db4.6_upgrade: Program version 4.6 doesn’t match environment version 4.4
db4.6_upgrade: DB_ENV->open: DB_VERSION_MISMATCH: Database environment version mismatch

Can’t start it manually.

debian-sks@dev:~$ /usr/sbin/sks recon
Fatal error: exception Bdb.DBError(“Program version 4.6 doesn’t match environment version 4.4″)

The log only shows:

2010-05-09 16:59:29 Opening log
2010-05-09 16:59:29 sks_db, SKS version 1.1.0
2010-05-09 16:59:29 Copyright Yaron Minsky 2002, 2003, 2004
2010-05-09 16:59:29 Licensed under GPL. See COPYING file for details
2010-05-09 16:59:29 http port: 11371
2010-05-09 16:59:29 Malformed entry
2010-05-09 16:59:29 Malformed entry
2010-05-09 16:59:29 Malformed entry
2010-05-09 16:59:29 Malformed entry
2010-05-09 16:59:29 Malformed entry
2010-05-09 16:59:29 Malformed entry
2010-05-09 16:59:29 Malformed entry
2010-05-09 16:59:29 Malformed entry
2010-05-09 16:59:29 Malformed entry
2010-05-09 16:59:29 Malformed entry
2010-05-09 16:59:29 Malformed entry
2010-05-09 16:59:29 Malformed entry
2010-05-09 16:59:29 Malformed entry
2010-05-09 16:59:29 Opening KeyDB database
2010-05-09 16:59:29 Shutting down database

The solution is ugly as hell, too:

root@dev:/ # su – debian-sks
debian-sks@dev:~$ cd DB
debian-sks@dev:~/DB$ db4.4_checkpoint -1
debian-sks@dev:~/DB$ db4.4_recover
debian-sks@dev:~/DB$ db4.4_archive
log.0000002839
log.0000002840
log.0000002841
log.0000002842
log.0000002843
log.0000002844
log.0000002845
debian-sks@dev:~/DB$ db4.6_archive -d
debian-sks@dev:~/dump$ cd ../PTree/
debian-sks@dev:~/PTree$ db4.4_checkpoint -1
debian-sks@dev:~/PTree$ db4.4_recover
debian-sks@dev:~/PTree$ db4.4_archive
debian-sks@dev:~/PTree$ db4.6_archive -d
debian-sks@dev:~/PTree$ logout
root@dev:/ # /etc/init.d/sks start
Starting sks daemons: sksdb.. sksrecon.. done.

Wow, our internal keyserver works again. Thank you, Debian…

This solution courtesy of Uwe Hermann, although it was for Suckwürstchen.

Upcoming migrations

03.04.2010 by tg@

I finally managed to move my arse and buy a new Socket 7 CPU fan for herc, two new 160 GB IDE HDDs for tear, and plan a number of other migrations. Within the next time, the SSL certificates will be renewed (changed away from CAcert to some as of yet undefined CA for the main (web)server and to ca.mirbsd.org for the secondary services), www will possible move to a dedicated box, cvs from herc to tear for sure though. I’m at gecko2@’s place right now though, so it’ll take a while more (obviously). I’ll take the chance to re-design a number of things during the process and clean up old, no longer used things, as well.

I know I should probably have written something about CLT (it was great, except for the social event, which confused everyone about the who where etc. and I had a headache and the sounds they provided (no music…) didn’t help either, but it was planned and exercised very well and much cleaner than ULB too ☺) and that I managed to do two geocaches in East Germany… and a plethora of other things (I did staff the Debian booth, there were neither a MirBSD nor FreeWRT booth after all; there is interest in makefs(8) but the 31/32-bit limit must go; etc). I’ve had a demanding three weeks at work though, and I’ll probably not write much content for the website anyway any more, but I’ll try to get more hacking done. mksh got more POSIX compliance, and we’re discussing about the things on the Austin Group mailing list. I’ll be writing a bootloaderloader for mika and Grml, with special consideration for a blind user. I need to get screws, RAM, a hard disc and a PSU for my new Cobalt Qube2 and put Debian on it to debug things. I plan to buy the upgrade kit (to 20 MiB RAM) and a new battery for nwt (and use glue to put the broken-off edge back there) just like I started renovating my hardware pool. OpenSSH needs an import, others may need work. So, I’ve got a TODO longer than a lifetime, so I get to pick my things ;-)

There will not be a MirBSD booth at LinuxTag in Berlin. If I’m going (even that’s not sure), I join a shared AllBSD booth, which seems to not happen, or… bsiegert@ will be at some conference for his Chemistry stuff again, and it’s too far for gecko2@ to attend, so I would’ve been alone anyway. At FrOSCon, though, we’ll be sure to happen (I’m even trying to cobble together a FreeWRT booth again, but there are not enough volunteers coming who aren’t expected as another booths’ staff).

gecko2@ upgraded ports/editors/nano and desired documentation, possibly in the form of a tutorial, on how to do it. And I hope bsiegert@ will remember that Google’s “Go” is the second one of that name and use something like ports/lang/google-go (on second thought, a company name in a directory is bad too). And there’s kencc in ports already so I’d like an Inferno port first.

ciruZ said that Syllable is pretty much dead… sad, since mksh now works on Haiku and both Syllable and Plan 9 had similar issues with it, so I was hoping we could get them fixed… (bsiegert@ is our resident Plan 9 expert, so I need to push him into looking at it.) Speaking of MirWorldDomination, /system/bin/sh on Android-x86 is an mksh(1) already ☺

Go

02.04.2010 by bsiegert@

Today was a fine day, which I spent at the excellent Zoo de Mulhouse. Alas, most of the plants there are still in “winter mode”.

Recently, i mentioned in a thread on reddit that Limbo (under Inferno) is “my favorite obscure programming language”. Someone else replied that “it is now called Go”. This led me to take a look at the Go programming language made by Google. Sure enough, there are big names behind it: Rob Pike and Ken Thompson, of Unix (and Plan9) fame, and also Russ Cox, one of the most prolific Plan 9 fans.

When you compile Go, the first thing that is built is a lib9, which contains Plan 9 code, such as the rune routines for UTF-8. The Go compiler is derived from kencc. For the 386 architecture (the one I tested), you get 8g (Go), 8c (C), 8l (linker) and 8a (assembler). For the record, there is also a Go compiler using gcc, which is able to call C code.

Leaving obvious syntax differences aside, Go indeed resembles Limbo quite closely. There is no first-class list data type however, and there exists a curious difference between arrays and slices. Slices are some sort of pointer to (part of) an array. Arrays are passed by-value to functions while slices are passed by reference, it seems. There is also an associative array type that maps one data type of your choice to another, for example a string to an int. Other Limbo niceties, such as easy string manipulations, are also present.

The first thing I tried was porting a scientific program I had written in Limbo before. The math module looks almost like its counterpart in Inferno but is missing the gemm() function (generic matrix multiplication) from BLAS3. Thus, I ported it from the Inferno sources, where gemm() is written in C. (By the way, that code looks like it has been ported from Fortran 77.) Porting from C just involves removing a few parentheses (in if and for clauses) and semicolons (just about everywhere).

I have not explored it much further yet. But it does look very interesting for system programming and similar things. The only thing missing now is a MirPort ...

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