November 2008 - l4-hackers - example.com Site

Back to UTCB IPC
by Marc CHALAND 11 Oct '09

11 Oct '09

Hi, I am back with my problem with UTCB IPC. To sum up the context : I use pure l4env applications. Here is the scenario between my server and my client : 1. client makes an UTCB IPC to manager. Manager does an l4rm_area_reserve, creates a rcv_fpage, creates worker and sends back worker thread id to client. 2. client allocates memory and associated flexpage and sends it to server. 3. UTCB IPC is sent to worker with 3 parameters : - on client side : utcb->values=0xbff00200: arg1=0x2 arg2=0x1 arg3=0x6 - on server side : utcb->values=0xbff00200: arg1=0x241401 arg2=0x0 arg3=0x7069776c It seems that 0xbff00200 is not mapped on the same memory on client and server side. As there is no problem for first IPC (utcb->values is also 0xbff00200), is there any potential problem with flexpage ? As utcb->values is still the same, what happens if several threads try to make UTCB IPC ? Another question : when I link my application with liblogserver.a, I have strange logs : .rm.sem.mainMain function returned. It seems that .rm .sem and .main are added by l4env, but I didn't find where. Regards Marc

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DDEkit for Linux2.6 from svn
by Shakthi Kannan 03 Jan '09

03 Jan '09

Hi, I would like to know from where I can get the DDEKit (Device Driver Environment) for Linux2.6 from svn? http://wiki.tudos.org/DDE/DDEKit >From the svn documentation: http://www.inf.tu-dresden.de/index.php?node_id=1735&ln=en ./repomgr modules lists the following: dice, fiasco, hello, l4env, l4linux-2.6-env. Thanks! SK -- Shakthi Kannan http://www.shakthimaan.com

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Problem with the configuring user-level code of L4Ka::Pistachio
by Святослав Сидоров 30 Nov '08

30 Nov '08

Hello! I'm trying to configure the user-level code of L4 as written in instruction: http://l4ka.org/projects/pistachio/ia32/gettingstarted.php but there is no configure file in the user directory: debian:/home/svet/l4dev/l4ka-pistachio-081128-01/ia32-user-build# ../user/configure --prefix=../ia32-user-install --with-kerneldir=../x86-kernel-build bash: ../user/configure: No such file or directory debian:/home/svet/l4dev/l4ka-pistachio-081128-01/ia32-user-build# cd ../user; ls apps config.mk.in configure.in contrib include INSTALL install-sh lib Makefile.in Mk README.HG serv util In INSTALL file I read that the configure file should be in the main source directory of L4: <...> The simplest way to compile Pistachio using separate build directories is: 1. Create a directory BUILDDIR to host the build tree. 2. `cd' to the newly created BUILDDIR directory and run the `configure' script located in the main source directory. For example, if you create a directory `SRCDIR/build' and `cd' to this directory, you can run `../configure' to invoke the configure script. <...> but there is no such file too: debian:/home/svet/l4dev/l4ka-pistachio-081128-01/user# cd ..; ls AUTHORS contrib doc ia32-user-build kernel tools user x86-kernel-build What should I do to build the L4? Also this problem is described in message: http://www.mail-archive.com/l4-hackers@os.inf.tu-dresden.de/msg03449.html With the best regards, Svet.

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Re: Problems with l4linux
by Valery V. Sedletski 28 Nov '08

28 Nov '08

On Thu, 20 Nov 2008 19:50:07 +0100, Adam Lackorzynski wrote: > >Those low-level things like GART are not unproblematic, best avoid them >if they seem to make problems (or proper analyse what's going on, much >harder...). > Yes, I'm trying to avoid them by now. On my desktop computer (AMD64) I disabled GART & Co. And on my notebook I disabled iTCO_vendor_support.ko and iTCO_wdt.ko (something watchdog-related) -- they were causing errors with call traces which hang the console. And the most interesting thing -- I found that when adding --isa=0x00800000 to the dm_phys commandline, the panic message disappears and Linux boots OK without errors at all! -- This does something with ISA DMA memory, as I read. It is strange that on AMD64 Linux boots OK without it, but it is needed on the notebook. So, maybe, this panic message is not a problem at all -- this is only configuration problem? Does this make the problem clear or is bootable ISO still needed (I'll trying to make it soon, yet encountered some problems with it -- and I can't reproduce the problem on desktop computer -- must figure out, on what type of hardware it appear. With qemu, all boots OK, so it seems not to be useful, as its emulated hardware does not cause problems, with no regard of --isa=... option) And still no additional messages either on linux console or on log server, only "Kernel Panic, not syncing, out of memory and no killable processes". And also "panic, waiting forever.." on log server. I can make screenshot though, but no useful info here. Maybe, I can recompile with additional debug messages enabled? I added "earlyprintk=1" and "console=ttyLv0" but still no additional messages. >> On my notebook I have ATI Radeon X300 Mobility PCI-express card, so, >> loading AGP drivers have no sense. As with desktop machine, I supposed >> that on notebook kernel panic occurs when loading some driver (maybe, >> video related -- I am not sure, if it makes a sense to load them in >> l4linux), but when I renamed all suspectable drivers, there were no >> errors with call traces, but the single kernel panic message remains, >> without other messages which could tell what causes it. > >Tried earlyprintk=1 on the Linux kernel command line? > Thanks, I added it. >> As I said, the notebook has no comports (I only have PCMCIA serial >> card and USB-to-serial converter); but desktop has them -- when I >> attached a nullmodem cable to the desktop (and connected from the >> notebook with terminal program using usbserial converter), I got debug >> messages from log server, but found nothing suspected (I could post >> logs there, but there are no call traces or other error messages in >> them -- maybe, there is a way to say linux to redirect error messages >> and call traces to log server?) > >There is. In the L4Linux configuration, in the Stub-drivers sub-menu, >enable 'Serial driver' and then use console=ttyLv0 on the kernel command >line. This should do the trick. > Now I got an empty linux console which begin output messages only starting with init process messages. Log server output ends with messages from interrupt service threads attaching to interrupts. But an error appears that linux cannot open /dev/console. I specified console=ttyLv0 but it still tries to open /dev/console. And, maybe, /dev/ttyLv0 must be created, but I don't know its major and minor numbers. >> Maybe, there is something to redirect >> log server messages through network or similar way, not via commport? >> Or, maybe, it's possible to redirect linux messages to log server and >> then from the same machine, to get/view these logs using l4env >> servers, not linux itself (linux is dead but l4env remains alive and >> maybe, I can get some post-mortem info, like logs or task memory dump >> or etc? Or get and save a trace buffer or similar?) (Just an idea -- >> what if include simple http server in l4env and serve log server >> messages, so, they can be viewed from any web browser? Maybe, >> something like this already exist?) > >There's the dmon application which is a DOpE application and a >log-server, i.e. it display log-messages in a window. >The other ideas are nice but do not exist. > Thanks. I also found a logcon application in l4con examples which is a l4con-aware log server. So, viewing log server messages is also possible in l4con environment -- I tried this, it works. Also, 1) with events server I was able to restart l4linux without rebooting -- just do Ctrl-Alt-Del in linux and then "l" option in run application to start it again. 2) by specifying "allow_cli" I was able to reboot computer in "run" application by pressing a tilde ("~") button. But 3) specifying "allow_cli" in run loader script was not sufficient to kill tasks with "run". When I try killing a hung L4Linux, a message appears in log that task F (run) is not allowed to kill tasks. Maybe, some additional option (to the "allow_cli" one) is needed? According the http server -- when I read the log server docs, I found that there is "--net" option that allow to access log server output via telnet! -- So, it appears that my idea is already implemented ;-) But this feature supports only four ethernet cards, unfortunately. I have rtl 8169 Gigabit ethernet and also have NE2000 compatible PCMCIA card on the laptop, but as I understood, PCMCIA is not supported (though, there is NE2000 support in log server) and 8169 is also don't supported. ;( > >I'd like to see the panic message, with the backtrace etc. to be better >able to judge what's going on. A classical screen-shot would also be ok. >Have you considered trying QEmu to play around? This makes all those >issues go away because you get the serial output into your terminal >etc... > As I said, no success with qemu as Linux boots OK with it. The backtrace is possible with calling strace when booting with init=/bin/sh and starting UDEV manually under strace. But here redirecting output to log server is needed, but "console=ttyLv0" still don't work. I can make screenshots then. WBR, valery PS: I forgot to mention -- returning to the problem with GPRS modem card -- this modem is not unique in that it don't work because of not getting high I/O memory area. -- I tried also two dialup PCMCIA modems (detected as ordinary PCMCIA modem/serial card) and one Cardbus serial card -- the same problem -- can't reserve high I/O memory region. So, this problem is not unique to my GPRS card, but it can be reproduced with any standard PCMCIA serial/modem card. (Just to know that this problem is common to all PCMCIA serial devices).

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Re: Problems with l4linux
by Valery V. Sedletski 20 Nov '08

20 Nov '08

On Mon, 27 Oct 2008 01:06:43 +0100, Adam Lackorzynski wrote: > >On Thu Oct 23, 2008 at 21:54:08 +1300, Valery V. Sedletski wrote: >> On Wed, 22 Oct 2008 19:12:59 +0200, Adam Lackorzynski wrote: >> >> ...skipped... >> >> So, this is iret instruction somewhere on return from a syscall, if I understood correctly. >> Maybe, my Fiasco config is wrong? > >Rather not. Can you tell me at which position the f.2 is in user-land? >That would be interesting. > This is the result of executing "tf.2" in kernel debugger: thread: f.02 <001e0801> prio: a0 mcp: ff mode: Con state: 001 ready %dl 001e0804 into wait for: polling: rcv descr: lcked by: ---.-- timeout : cpu time: 2.000 ms timeslice: 4000/10000 ╣s pager : f.00 cap: ---.-- utcb: ffe34200 preemptr: 0.00 not monitored ready lnk: ???.?? 5.00 prsnt lnk: f.04 f.00 EAX=00000000 ESI=001e0801 DS=0023 EBX=a0051454 EDI=00000000 ES=0023 iret ECX=0000000d EBP=afeffe40 GS=0043 lea 0x0(%esi),%esi EDX=afeffe58 ESP=c03c17ec SS=0010 trap 13 (General Protection), error 00000070, from kernel mode CS=0008 EIP=f003622b EFlags=00203246 001e0815 cli c03c17ec f003622b 00000008 00203246 [eacff102] 00000073 00203296 afeffe00 0000007b 001e0818 into the [eacff102] dword was highlighted in backtrace. So, as I understood this, this marks current stack frame. Here we see that previous stack frame is ip=0xf003622b, cs=0x8, eflags=0x00203246 is respectively ip, cs and eflags taken off from the stack by previous iret instruction. Current iret must take off the next frame: eip=0xeacff102, cs=0x73, eflags=0x00203296. Here we can see that selector cs=0x73 is ring3 and eip is 0xeacff102. And also, unassembly at eip=0xeacff102: eacff100 int $0x31 eacff102 ret -- An entering the syscall? <001e0801> -- What is it? If it is an address from where int 0x32 is called then instructions at this point are: 001e07fe dec %dl 001e0800 into 001e0801 cli 001e0802 dec %dl 001e0804 into 001e0805 cli an address 001e0800 (into) is not in CS segment of vmlinux executable (no such address in objdump output) So, what is it? Corrupt stack? Or it is not a return address but something different? >X is very demanding wrt permissions. More recent version should behave >better though. > >> And the question: what does cli instruction do? I guess this must trigger an I/O page fault for I/O >> pages to be mapped? Am I right? > >CLI disables interrupts. Allowing this in user-land is a major security >breach. > I know. But in ioport.c you do CLI and then STI immediately. What it does? >> >I guess not. Which address? Anyway, I guess it should ioremap those... >> > .... > >Some of those addresses are quite low but unfortunately I don't have an >idea what they're used for. > The Cardbus controller uses these addresses, according to windows Device manager: 0xb8008000-0xb8008fff 0xfebff000-0xfebfffff 0xfabff000-0xfebfefff 0x000db000-0x000dbfff and modem itself uses none, only i/o and irq Also, I searched logs and found that piece: Oct 21 04:54:14 localhost kernel: Serial: 8250/16550 driver $Revision: 1.90 $ 4 ports, IRQ sharing enabled Oct 21 04:54:14 localhost kernel: cs: memory probe 0xb8000000-0xb80fffff:__l4x_ioremap: Requested region at b8010000 [0x1000 Bytes] Oct 21 04:54:14 localhost kernel: cs: memory probe 0x70000000-0x700fffff: excluding 0x70000000-0x700fffff Oct 21 04:54:14 localhost kernel: cs: warning: no high memory space available! (This was in the log with info level (there are also error and warning levels)), so, as I understood, this is not fatal. Also here are ioremaps, so, they are present. WBR, valery

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Interested with the TUDOS Demo CD's Virtual Linux
by Neohtm 18 Nov '08

18 Nov '08

Hie, I'm new to the L4 kernel. I'd tried on the TUDOS demo cd and i'm quite interest with the linux virtualization on small kernel system. Can someone show me how to achieve that? I'd downloaded the Fiasco kernel and L4linux via SVN but i don't have the idea on how to make it works. Thanks -- Best Regards, Neoh Tze Ming Research Officer Faculty of Engineering and Technology Multimedia University Melaka, Malaysia

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Re: L4 for Openmoko FreeRunner
by Shakthi Kannan 13 Nov '08

13 Nov '08

Hi, --- On Thu, Nov 13, 2008 at 9:44 AM, Gernot Heiser <gernot(a)ok-labs.com> wrote: | I'm not aware of any L4 version officially supporting the FreeRunner | (GTA02). OKL4 has been ported to the GTA01 (see http://okl4.org) As | the two platforms seem to have the same CPU core and a similar SoC, | getting it going on the GTA02 would probably not be too hard. \-- Thanks! SK -- Shakthi Kannan http://www.shakthimaan.com

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nethub and l4linux
by Mikhail Savchenko 10 Nov '08

10 Nov '08

Are there any working samples of nethub with l4linux as it's broken for running with flips? There are interesting the menu.lst configuration issues for nethub and tun/tap infrastructure for l4linux setting up. Thank you.

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question: is there any implementation of fiasco on s2410(samsung arm920tdmi)?
by zhhwu 10 Nov '08

10 Nov '08

hi all: i want to migrate a implementation of fiasco to s2410, is there any already existed? i find that there are implementations on SA1110 and PXA. And i find that the ARM project of Pistachio has status: discontinued. (why ?) best regards! zhhwu

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L4 for Openmoko FreeRunner
by Shakthi Kannan 08 Nov '08

08 Nov '08

Hi, Where can I find documentation on using L4 with the Openmoko FreeRunner? I've seen this post for the Neo1973: http://lists.okl4.org/pipermail/developer/2007-December/000504.html Appreciate any pointers in this regard, Thanks! SK -- Shakthi Kannan http://www.shakthimaan.com

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