l4-hackers August 2006

l4-hackers@os.inf.tu-dresden.de

27 participants
37 discussions

GDB on Fiasco-UX?
by Andreas Niederl 07 Aug '06

07 Aug '06

Hi, is Fiasco-UX suited for debugging with GDB? I noticed the lines generic.inc: [ -n "$RUN_GDB" ] && gdb_wrap="gdb $GDB_ARGS --args" generic.inc: $gdb_wrap $FIASCODIR/$FIASCO in l4/tools/runux/generic.inc and tried to run GDB by setting the RUN_GDB variable to something when calling one of the predefined ux-scripts, but it always results in segmentation faults concerning the calls to the cli and sti instructions. GDB output: Welcome to Fiasco(ux)! DD-L4(v2)/x86 microkernel (C) 1998-2006 TU Dresden Rev: Thu Aug 3 18:16:37 2006 compiled with gcc 4.0.2 for Intel Pentium 4 Detaching after fork from child process 5989. Program received signal SIGSEGV, Segmentation fault. Dirq::alloc (this=0xce93f, t=0x639f5000, ack_in_kernel=802816) at auto/processor.h:128 128 asm volatile ("cli" : : : "memory"); (gdb) $ gdb --version GNU gdb Red Hat Linux (6.3.0.0-1.84rh) Regards, Andi

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Can we really think at a new OS design nowadays ?
by Guillaume FORTAINE 06 Aug '06

06 Aug '06

Hello, Here is the start point of my reflexion : http://lists.gnu.org/archive/html/l4-hurd/2006-04/msg00053.html I believe that we can do extremely complex and reliable software with a few people, thanks to the powerful formal and design tools available now. Moreover, I think that this OS has to support three key things to be able to survive ( an essential key to have a long term development ) : synergy ,transition & usability. -The first one is the start of any important project : developers can have the possibility to share complex ideas with minimum requirements and to integrate them in a coherent environment. ( see http://www.gnu.org/software/hurd/ => 23 years old and even the goals are not well defined ) -The second feature provide any user the ability to develop on it with existing materials and to have the support of developers of legacy OS. ( see www.tunes.org => maybe too innovative and this : http://symbolx.org/ddf_news.html ). -The third one needs that a device driver framework needs to be rapidly envisaged. ( again http://www.gnu.org/software/hurd/ => no good driver kit at this date, the same for linux : http://www.kroah.com/log/2006/05/24/, 15 years later ). Who wants to have an OS that boots only a black screen with a beep sound ? If we follow the Moore law, an OS design of the future would be thought for quadruple play ( mobility, audio, video, Internet ) and security of course. Time is maybe our worst ennemy : more and more technologies are created day by day and we need to understand and to be able to use them And it's maybe our better friend : as the hardware/software becomes mor and more complex, the tools to develop them becomes more powerful too. The tools developed to understand and create complex systems give us the ability to design and implement an OS design secure & reliable. Here are my guidelines to start : _ First : Users collaboration :_ http://www.opencroquet.org _Second - Formal tools :_ http://www.fmeurope.org Z method : http://czt.sourceforge.net/ http://www.zuser.org/ B-method : http://en.wikipedia.org/wiki/B-Method http://rodin-b-sharp.sourceforge.net/index.html _Second - Software design :_ http://planetmde.org/ http://distributed-software.blogspot.com _ Third - Language Designer's Toolkit :_ http://lambda-the-ultimate.org/node/1562 http://hlvm.org/ Abstraction will be the solution, Best Regards, Guillaume FORTAINE

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Invalid l4x_hybrid_return ?
by Oskar Senft 04 Aug '06

04 Aug '06

Hi L4Linux experts! We are currently doing some experiments with L4Linux L4BD and encounter a problem during a connect call by IPC (see logs). l4x_hybrid_return: Invalid hybrid return for 21.03 (0x00000000, d, 402, -1, b7a2a25e)! l4x_hybrid_return: Currently running: 00.00 I don't know what this error means and how we produced that. We use the L4Linux L4BD as shipped with L4Linux without any patches. What can we do? Regards Oskar. -- Sirrix AG security technologies - http://www.sirrix.com Oskar Senft eMail: o.senft(a)sirrix.com Tel +49 (681) 936 251 - 119 Fax +49 (681) 936 251 - 500 get public key from keyserver Fingerprint 6FC6 3E44 233F 7F4B 33C7 A8D0 2EDA F3BA B5A3 0BA4 This message may contain confidential and/or privileged information. If you are not the addressee, you must not use, copy, disclose or take any action based on this message or any information herein. If you have received this message in error, please advise the sender immediately by reply e-mail and delete this message. l4lx | ======> L4Linux 2.6 starting... <======== l4lx | Linux version 2.6.16-l4 (osk@olaptop) (gcc version 3.3.6 (Debian 1:3. l4lx : 3.6-13)) #4 Thu Aug 3 15:19:50 CEST 2006 l4lx | Binary name: vmlinuz26-minimal l4lx | Kernel command line (6 args): mem=64M noreplacement l4bd.l4blk_name=b l4lx : lockenc root=/dev/hda1 panicblink=0 lang=de l4lx | Image: 00400000 - 00727000 [3228 KiB]. l4lx | Areas: Text: 00400000 - 0063d000 [2292kB] (a bit longer) l4lx | Data: 0063d000 - 00681520 [273kB] l4lx | Initdata: 00684000 - 006a8000 [144kB] l4lx | BSS: 006a8000 - 00725060 [500kB] l4lx | l4lx_thread_create: Created thread 21.03 (server) l4lx | main thread will be 21.03 l4lx | l4env_register_pointer_section: addr = 0063d000 size = 958464 l4lx | l4env_linux_startup thread 3. l4lx | sec-w-init: virt: 0x0063d000 to 0x00726fff [936 KiB] l4lx | sec-w-init: Number of physical regions: 1, 958464 Bytes l4lx | sec-w-init: 1: Phys: 0x006ea000 to 0x007d4000, Size: 958464 l4lx | main thread: received startup message. l4lx | Main thread running, waiting... l4lx | setup_l4env_memory: Forcing superpages for main memory l4lx | Main memory size: 64MB l4lx | Main memory: virt: 0x00800000 to 0x047fffff [65536 KiB] l4lx | Main memory: Number of physical regions: 1, 67108864 Bytes l4lx | Main memory: 1: Phys: 0x11400000 to 0x15400000, Size: 67108864 l4lx | Filling lower ptabs... l4lx | Done (1075 entries). l4lx | l4lx_thread_create: Created thread 21.04 (timer.i0) l4lx | Starting L4FB via CON con | vc_loop(): vc[2] running as D.08 l4lx | l4lx_thread_create: Created thread 21.05 (L4ConInput) con | vc_open_out(): vc[2] 1024x768@16, gmode:0x35 l4lx | l4fbcon: 1024x750 2bypp, size: 1540096 l4lx | l4lx_thread_create: Created thread 21.06 (CON refresher) l4lx | atexit(function = 0x00526130) called l4lx | l4x_hybrid_return: Invalid hybrid return for 21.03 (0x00000000, d, 40 l4lx : 2, -1, b7a2a25e)! l4lx | l4x_hybrid_return: Currently running: 00.00 backtrace (thread 21.03, fp=0080defc, pc=005e4273): #1 005e4273 : l4blk_driver_open_call + 0x53 ... v/drops-060505/l4/pkg/generic_blk/idl/OBJ-x86-l4v2/blk-client.c:82 #2 005e341e : l4blk_open_driver + 0xbe ... /devenv/drops-060505/l4/pkg/generic_blk/lib/client/src/driver.c:133 #3 00698e9a : l4bd_init + 0x3a /home/osk/tmp/drops-060505/l4linux-2.6-minimal/drivers/block/l4bd.c:317 #4 0068479b : do_initcalls + 0x2b /home/osk/tmp/drops-060505/l4linux-2.6-minimal/init/main.c:576 #5 0068483c : do_basic_setup + 0x1c /home/osk/tmp/drops-060505/l4linux-2.6-minimal/init/main.c:615 #6 00400090 : init + 0x30 /home/osk/tmp/drops-060505/l4linux-2.6-minimal/init/main.c:687 #7 00406389 : kernel_thread_start + 0x29 ... s-060505/l4linux-2.6-minimal/arch/l4/kernel/arch-i386/process.c:199 #8 0040635e : ret_kernel_thread_start + 0x6 ... s-060505/l4linux-2.6-minimal/arch/l4/kernel/arch-i386/process.c:174 #9 0040001c : rest_init + 0x1c /home/osk/tmp/drops-060505/l4linux-2.6-minimal/init/main.c:399 #10 0068471b : start_kernel + 0x16b /home/osk/tmp/drops-060505/l4linux-2.6-minimal/init/main.c:546 #11 0068ad3f : l4env_linux_startup + 0xbf ... /osk/tmp/drops-060505/l4linux-2.6-minimal/arch/l4/kernel/main.c:695 #12 000186d3 : l4th_thread_start + 0x73 ... pdate-060505-134059/drops-060505/l4/pkg/thread/lib/src/create.c:72 #13 0001b9a6 : l4th_thread_entry + 0x16 ... opsupdate-060505-134059/drops-060505/l4/pkg/thread/lib/src/l4.c:93 #14 00420804 : .text.lock.rcupdate + 0xa /home/osk/tmp/drops-060505/l4linux-2.6-minimal/kernel/rcupdate.c:603

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Re: The future of L4
by Guillaume FORTAINE 03 Aug '06

03 Aug '06

Hello all, Here are two interesting links : http://www.nondot.org/sabre/os/articles http://www.ps.uni-sb.de/alice/ Best regards, Guillaume FORTAINE

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multithreaded tcp echo server problem & flips
by David Silcott 03 Aug '06

03 Aug '06

hello all, I've ported my multithreaded tcp server to L4 using flips but I am having some problems getting it to run properly. It is a quite a bit to explain so I've written a simple tcp echoserver to demonstrate my problem. The following happens when the server starts and the client connects and send data. 1. Echoserver starts and listens on port 2222 2. client connects, server creates a child_server thread to service client and starts listening again 3. client sends string to child_server thread which is received. child_server however is unable to complete send(echo), it seems to be blocked at this point. 4. The send is only completed when another client attempts a connect(..and the server moves on from the accept(..) statement). I have appended my code at the bottom of this mail maybe someone can spot my mistake and highlight it. To check if I've used the threads properly I also wrote a program in which each thread prints the numbers from 0 to 9 and that runs fine. So I am pointing my finger and the recv(), accept() and send() functions in my echo server :-| Any suggestions will be greatly appreciated. cheers david ============================================================================= /*** GENERAL INCLUDES ***/ #include <stdlib.h> #include <stdio.h> #include <unistd.h> #include <sys/socket.h> #include <sys/types.h> #include <netinet/in.h> #include <arpa/inet.h> #include <string.h> /*** L4 INCLUDES ***/ #include <l4/names/libnames.h> #include <l4/thread/thread.h> #include <l4/log/l4log.h> #include <l4/dm_mem/dm_mem.h> #define BUF_SIZE 100 l4_threadid_t srv; char LOG_tag[9] = "tcpecho"; int data_key; struct th_data{ int c; //socket char foo[10]; //.... }; /* exit handler */ void child_exit(l4thread_t thread, void * data); void child_exit(l4thread_t thread, void * data){ struct th_data *ptr = (struct th_data *)data; /* close the connection and free up memory used by data structure*/ close(ptr->c); free(ptr); } /* declare exit function descriptor */ L4THREAD_EXIT_FN(exit_fn,child_exit); void child_server(void *data); void child_server(void *data){ char databuf[BUF_SIZE]; struct th_data *dptr = (struct th_data *)data; int ret, sock, n; void *ret_val; l4thread_t id; sock = dptr->c; LOG("got socket\n"); /* register exit function */ ret = l4thread_on_exit(&exit_fn, // exit function descriptor data // data pointer ); if (ret < 0){ /* register error function failed */ LOG_Error("Register error function failed\n"); } id = l4thread_myself(); LOG("Server thread starting with id %u\n",id); /* we are up */ if (l4thread_started(ret_val) < 0){ /* startup notification failed */ LOG_Error("Startup notification failed\n"); } LOG("Entering loop to wait for requests on socket %d.... \n",sock); while (1){ LOG("At top of while loop\n"); if((n = recv(sock, databuf, BUF_SIZE-1, 0)<=0)){ LOG_Error("recv failed %d returned \n",n); break; } databuf[4] = '\0'; databuf[5] = '\n'; LOG("GOT MESSAGE\n"); LOG(">%s; sending ....\n",databuf); databuf[0] = 'X'; send(sock,databuf,6,0); memset(databuf,0,BUF_SIZE); LOG("Looping\n"); } /* Call on exit function to terminate */ l4thread_exit(); } /* Start the server */ int main(int argc, char *argv[]){ int c, s,err, ret_val, errcount=0; struct sockaddr_in addr; if ((argc < 2) || strcmp("--nowait", argv[1])) while (names_waitfor_name("ifconfig", &srv, 30000) == 0) { LOG("Client(main): \"mini_ifconfig\" not available, keep trying..."); } memset(&addr, 0, sizeof(addr)); addr.sin_addr.s_addr = htonl(INADDR_ANY); addr.sin_family = AF_INET; addr.sin_port = htons(2222); LOG("try to open socket"); if ((s=socket(AF_INET, SOCK_STREAM, IPPROTO_TCP)) < 0) { LOG("Couldn't create socket"); return -1; } if (bind(s, (struct sockaddr *)&addr, sizeof(struct sockaddr)) < 0) { LOG("Couldn't bind"); return -1; } LOG("bound to socket %d, call listen",s); if ((err=listen(s, 1)) < 0) { LOG("listen(%d): %d", s, err); return -1; } LOG("echo server is up and accepting..."); names_register("echoserver"); while(1){ struct sockaddr dummyaddr; int addrlen; l4thread_t th; struct th_data *th_dptr; LOG("waiting for another connection\n"); if ((c=accept(s, &dummyaddr, &addrlen)) < 0) { LOG("accept(%d): %d", s, c); if (++errcount > 10) { LOG("maximum error count reached---giving up..."); exit(1); } continue; } LOG("Allocating thread data struct\n"); th_dptr = (struct th_data*)l4dm_mem_allocate( sizeof(struct th_data), L4DM_CONTIGUOUS); memset(th_dptr,0,sizeof(struct th_data)); th_dptr->c = c; LOG("Got a connection request, creating thread to handle client on socket %d\n", c); th = l4thread_create( child_server ,(void *)th_dptr ,L4THREAD_CREATE_SYNC); ret_val = l4thread_startup_return(th); /* Thread started ... listening for other requests */ LOG("thread created ... listening again\n"); } return 0; } __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com

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Re: The future of L4
by Guillaume FORTAINE 03 Aug '06

03 Aug '06

Hello all, I believe that the Mozart-Oz language could be a marvellous start point : object-oriented, concurrency, logic verification, security (planned)... What do we need now ? A good kernel design : security, asynchronous IPC, threading, real time scheduler A compiler : parser and optimization ( i think a sort of Elsa & Mozart-oz front-end for llvm ) A driver development environment : I believe the most time consuming part Forget Glibc .... or a poor fork of this => a new library design will be a good challenge too ;-) ! Powerful tools to reengineer legacy programs : http://www.program-transformation.org/Transform/WebHome 1 year of work and 100 very good programmers at least, and I think we will be able to enjoy it ... ;-) ! I am contacting some of the hall of fame, preparing my weapons, no problem. Makus & Neal were too weak because too few, but thanks to their effort, they show us the good way : we can revolutionize the world : linux was only a start point, it's time to port open source philosophy and community to a "military grade" quality ;-) ! Nowadays, is GNU really GNU is not Unix ( I would say GNU is only Linux ... ). Open source life behind a legacy OS ( 30 years ) design : Unix ( & C language too...) Hey guys, 15 years of development and I send you a mail with a LiveCd : very impressive, all my hardware is detected ( sound & video ok) => better than M$ ... But the security and the " raw" performance are indeed disappointing ( debian.org hacked 2 times in 2 years => 2000 developers behind ... ) kernel.org shut down one week ( ext3 ... ) Why an asynchronous IPC and a massively multithread model ? Asynchronous, like in real life : each one takes it times ;-) ! Massively multithread : performance, of course :-) ! I believe that security could be "easily" implemented with a good logic framework, we have marvellous tools to do that. Best regards, Guillaume FORTAINE

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Re: The future of L4
by Guillaume FORTAINE 01 Aug '06

01 Aug '06

Hello, I believe we need only one language and not multiple languages : why ? There are few developers for L4, no need to divide them .... C++ is for me the best language ever : In the order ;-) !: Hardware design : http://www.systemc.org/ Low level optimization : http://llvm.org llvm is for fpga programming (used by los alamos ;-) !) : High level programming : c++ with concurrency : u++ http://plg.uwaterloo.ca/~usystem/uC++.html Metaprogramming : http://opencxx.sourceforge.net/ No language was so powerful ! If you hate unix, you can try plan9 : http://cm.bell-labs.com/plan9/ Future plans : An alpha kernel for work ( mix of L4.x2 v6 and L4.sec) A robust file system ( I think data log like nilfs with encryption support => trustedFS) A device driver development framework (like linux driver develoment kit) Support for sound/video I sincerely believe that we need to focus on the best things that Linux produces and put our efforts to simplify them (one file system, sound system, video system, desktop environment system) to reasonably produce an alpha os usable and not to wait 2020 or so to have only an IDE driver ... Best Regards, Guillaume FORTAINE

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l4-hackers August 2006