From: Robin L. P. <rlp...@di...> - 2005-09-27 00:24:39
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I have UML set up far enough that it will allow me to log in in single user mode, and networking is set up (in as much as I can ping the host and the host can ping the guest). inetd runs fine. However, as soon as I run sshd by any means, the guest hangs. I have no idea what to do about this. Help? -Robin -- http://www.digitalkingdom.org/~rlpowell/ *** http://www.lojban.org/ Reason #237 To Learn Lojban: "Homonyms: Their Grate!" Proud Supporter of the Singularity Institute - http://singinst.org/ |
From: Jeff D. <jd...@ad...> - 2005-09-27 02:12:44
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On Mon, Sep 26, 2005 at 05:24:30PM -0700, Robin Lee Powell wrote: > However, as soon as I run sshd by any means, the guest hangs. I > have no idea what to do about this. Help? Are you sure the guest hangs? I.e. you can't ping it any more, consoles freeze, etc? If not, then it might be an entropy shortage, and the UML random driver might be handy. If so, then information like the version and a stack trace would be good. Jeff |
From: Jim C. <ji...@ma...> - 2005-09-27 03:34:28
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On Mon, 26 Sep 2005, Jeff Dike wrote: > On Mon, Sep 26, 2005 at 05:24:30PM -0700, Robin Lee Powell wrote: > > However, as soon as I run sshd by any means, the guest hangs. I > > have no idea what to do about this. Help? > > If not, then it might be an entropy shortage, and the UML random driver > might be handy. On my SuSE 9.3 installation, openssh-3.9p1-12 uses libcrypto-0.9.7 from openssl-0.9.7e-3. According to their FAQ http://www.openssl.org/support/faq.html#USER1 the library will use /dev/urandom (or /dev/random if no urandom) to seed the random generator. Thus it should not block even if entropy is exhausted. Even so, UML's tend to have much lower entropy production than the host, like by a factor of 100, so the random pass-through driver is a really good idea. Hmm, /dev/urandom does exist within the guest, right? If neither device can be found, libcrypto requires an initialization call which I didn't read the section about, but which probably involves hanging if it isn't done. James F. Carter Voice 310 825 2897 FAX 310 206 6673 UCLA-Mathnet; 6115 MSA; 405 Hilgard Ave.; Los Angeles, CA, USA 90095-1555 Email: ji...@ma... http://www.math.ucla.edu/~jimc (q.v. for PGP key) |
From: Robin L. P. <rlp...@di...> - 2005-09-27 04:06:20
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On Mon, Sep 26, 2005 at 08:34:16PM -0700, Jim Carter wrote: > On Mon, 26 Sep 2005, Jeff Dike wrote: > > On Mon, Sep 26, 2005 at 05:24:30PM -0700, Robin Lee Powell wrote: > > > However, as soon as I run sshd by any means, the guest hangs. I > > > have no idea what to do about this. Help? > > > > If not, then it might be an entropy shortage, and the UML random driver > > might be handy. > > Hmm, /dev/urandom does exist within the guest, right? If neither > device can be found, libcrypto requires an initialization call > which I didn't read the section about, but which probably involves > hanging if it isn't done. crw-rw-rw- 1 root root 1, 8 Apr 21 2004 /dev/random cr--r--r-- 1 root root 1, 9 Sep 27 04:02 /dev/urandom For the record. -Robin -- http://www.digitalkingdom.org/~rlpowell/ *** http://www.lojban.org/ Reason #237 To Learn Lojban: "Homonyms: Their Grate!" Proud Supporter of the Singularity Institute - http://singinst.org/ |
From: Robin L. P. <rlp...@di...> - 2005-09-27 04:30:58
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On Mon, Sep 26, 2005 at 09:13:15PM -0400, Jeff Dike wrote: > On Mon, Sep 26, 2005 at 05:24:30PM -0700, Robin Lee Powell wrote: > > However, as soon as I run sshd by any means, the guest hangs. I > > have no idea what to do about this. Help? > > Are you sure the guest hangs? I.e. you can't ping it any more, > consoles freeze, etc? Exactly that, yes. I've never let it go more than a few minutes. > If so, then information like the version and a stack trace would > be good. Debian unstable; 2.4.26-3um-1 Started with the Debian-3.0r2.ext2 image, which I haven't done much with. I can post my exact procedure if you like. Full strace at http://teddyb.org/~rlpowell/media/big/uml.strace.gz, but without -f (it wouldn't work for some reason; said "ptrace: Operation not permitted" even when run as root). During the hang, the end of the file says: ptrace(PTRACE_CONT, 8924, 0, SIGUSR2) = 0 waitpid(-1, [{WIFEXITED(s) && WEXITSTATUS(s) == 1}], WUNTRACED) = 8924 --- SIGCHLD (Child exited) @ 0 (0) --- waitpid(-1, After I run pkill, the following is added: 0xbffff608, WUNTRACED) = ? ERESTARTSYS (To be restarted) --- SIGTERM (Terminated) @ 0 (0) --- rt_sigaction(SIGINT, {SIG_DFL}, {0xa000f1b0, [], SA_RESTORER|SA_NOMASK|SA_ONESHOT, 0xa0201ad8}, 8) = 0 --- SIGCHLD (Child exited) @ 0 (0) --- rt_sigaction(SIGTERM, {SIG_DFL}, {SIG_DFL}, 8) = 0 rt_sigaction(SIGHUP, {SIG_DFL}, {0xa000f1b0, [], SA_RESTORER|SA_NOMASK|SA_ONESHOT, 0xa0201ad8}, 8) = 0 getpid() = 8473 kill(8504, SIGKILL) = 0 kill(8483, SIGKILL) = 0 kill(8485, SIGKILL) = 0 kill(8487, SIGKILL) = 0 kill(8489, SIGKILL) = 0 kill(8491, SIGKILL) = 0 kill(8493, SIGKILL) = 0 kill(8495, SIGKILL) = 0 kill(8497, SIGKILL) = 0 kill(8502, SIGKILL) = 0 kill(8887, SIGKILL) = 0 kill(8897, SIGKILL) = 0 kill(8920, SIGKILL) = 0 kill(8924, SIGKILL) = -1 ESRCH (No such process) kill(8478, SIGKILL) = 0 kill(8499, SIGKILL) = -1 ESRCH (No such process) waitpid(8499, NULL, 0) = -1 ECHILD (No child processes) close(34) = -1 EBADF (Bad file descriptor) close(33) = -1 EBADF (Bad file descriptor) rt_sigprocmask(SIG_UNBLOCK, [], [IO], 8) = 0 rt_sigprocmask(SIG_BLOCK, [ALRM VTALRM IO], NULL, 8) = 0 rt_sigprocmask(SIG_UNBLOCK, [ALRM VTALRM], [ALRM VTALRM IO], 8) = 0 rt_sigprocmask(SIG_BLOCK, [IO], NULL, 8) = 0 rt_sigprocmask(SIG_UNBLOCK, [], [IO], 8) = 0 rt_sigprocmask(SIG_BLOCK, [ALRM VTALRM IO], NULL, 8) = 0 rt_sigprocmask(SIG_UNBLOCK, [ALRM VTALRM], [ALRM VTALRM IO], 8) = 0 rt_sigprocmask(SIG_BLOCK, [IO], NULL, 8) = 0 rt_sigprocmask(SIG_UNBLOCK, [], [IO], 8) = 0 rt_sigprocmask(SIG_BLOCK, [ALRM VTALRM IO], NULL, 8) = 0 rt_sigprocmask(SIG_UNBLOCK, [ALRM VTALRM], [ALRM VTALRM IO], 8) = 0 rt_sigprocmask(SIG_BLOCK, [IO], NULL, 8) = 0 kill(8498, SIGKILL) = -1 ESRCH (No such process) waitpid(8498, NULL, 0) = -1 ECHILD (No child processes) getpid() = 8473 kill(8500, SIGKILL) = 0 waitpid(8500, NULL, 0) = -1 ECHILD (No child processes) open("/dev/null", O_RDONLY|O_NONBLOCK|O_DIRECTORY) = -1 ENOTDIR (Not a directory) open("/home/mooix/.uml/240", O_RDONLY|O_NONBLOCK|O_LARGEFILE|O_DIRECTORY) = 33 fstat64(33, {st_mode=S_IFDIR|0755, st_size=4096, ...}) = 0 fcntl64(33, F_SETFD, FD_CLOEXEC) = 0 getdents64(33, /* 4 entries */, 4096) = 104 unlink("/home/mooix/.uml/240/pid") = 0 unlink("/home/mooix/.uml/240/mconsole") = 0 getdents64(33, /* 0 entries */, 4096) = 0 rmdir("/home/mooix/.uml/240") = 0 munmap(0x40000000, 4096) = 0 exit_group(1) = ? -Robin -- http://www.digitalkingdom.org/~rlpowell/ *** http://www.lojban.org/ Reason #237 To Learn Lojban: "Homonyms: Their Grate!" Proud Supporter of the Singularity Institute - http://singinst.org/ |
From: Robin L. P. <rlp...@di...> - 2005-09-27 18:52:05
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On Mon, Sep 26, 2005 at 09:30:53PM -0700, Robin Lee Powell wrote: > On Mon, Sep 26, 2005 at 09:13:15PM -0400, Jeff Dike wrote: > > On Mon, Sep 26, 2005 at 05:24:30PM -0700, Robin Lee Powell > > wrote: > > > However, as soon as I run sshd by any means, the guest hangs. > > > I have no idea what to do about this. Help? > > > > Are you sure the guest hangs? I.e. you can't ping it any more, > > consoles freeze, etc? > > Exactly that, yes. I've never let it go more than a few minutes. > > > If so, then information like the version and a stack trace would > > be good. > > Debian unstable; 2.4.26-3um-1 > > Started with the Debian-3.0r2.ext2 image, which I haven't done > much with. I can post my exact procedure if you like. It's not just sshd, it turns out; just happened during a rather massive apt-get: Get:51 http://http.us.debian.org stable/main exim 3.36-16 [759kB] Fetched 15.3MB in 30m3s (8507B/s) Preconfiguring packages ... Tried to segfault it so I could get a core file, and got: Tracing thread segfault at address 0x0, ip 0xa0217b6b on the console, but it didn't die (or dump core). Regular kill did cause it to dump core, though. Or maybe it was just taking a really, really long time to dump all that stuff out. Dunno. Boy, my machine is basically totally unusable right now. Yeesh. Several minutes of type ahead and such. Dumping 512MiB to disk (it made two core files) from RAM on a machine with a fully encrypted disk turns out be painful. :-) gdb on the core file, unfortunately, gives nothing useful. Just a (very) long list of things like: #12009 0x00000024 in ?? () #12010 0xc890ba00 in ?? () #12011 0x5489a019 in ?? () So no help there, but if someone wants to provide me with a debugging symbols version, I'll try that. On the off chance that it matters, here's my start command: linux mem=256M ubd0=Debian-3.0r2.ext3 con=null con0=fd:0,fd:1 con1=none eth0=daemon single If people have other things I should try to debug this, I'll be happy to do them. -Robin |
From: Blaisorblade <bla...@ya...> - 2005-09-28 12:07:23
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On Tuesday 27 September 2005 20:52, Robin Lee Powell wrote: > On Mon, Sep 26, 2005 at 09:30:53PM -0700, Robin Lee Powell wrote: > > On Mon, Sep 26, 2005 at 09:13:15PM -0400, Jeff Dike wrote: > > > On Mon, Sep 26, 2005 at 05:24:30PM -0700, Robin Lee Powell > > > wrote: > > > > However, as soon as I run sshd by any means, the guest hangs. > > > > I have no idea what to do about this. Help? > > > Are you sure the guest hangs? I.e. you can't ping it any more, > > > consoles freeze, etc? > > Exactly that, yes. I've never let it go more than a few minutes. > > > If so, then information like the version and a stack trace would > > > be good. > > Debian unstable; 2.4.26-3um-1 Ah, they went to -3um, at least... however, you'd probably better try 2.4.28-bs2 from my homepage (applied on latest 2.4, i.e. 2.4.31) > > Started with the Debian-3.0r2.ext2 image, which I haven't done > > much with. I can post my exact procedure if you like. > It's not just sshd, it turns out; just happened during a rather > massive apt-get: > Get:51 http://http.us.debian.org stable/main exim 3.36-16 [759kB] > Fetched 15.3MB in 30m3s (8507B/s) > Preconfiguring packages ... I.e. it went to Sarge, right? Ok, I'd first check the /lib/tls issue (shouldn't happen with 2.4 guests, but still check) and the "upgrade UML" thing. -- Inform me of my mistakes, so I can keep imitating Homer Simpson's "Doh!". Paolo Giarrusso, aka Blaisorblade (Skype ID "PaoloGiarrusso", ICQ 215621894) http://www.user-mode-linux.org/~blaisorblade ___________________________________ Yahoo! Mail: gratis 1GB per i messaggi e allegati da 10MB http://mail.yahoo.it |
From: Robin L. P. <rlp...@di...> - 2005-09-28 19:16:08
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On Wed, Sep 28, 2005 at 02:06:19PM +0200, Blaisorblade wrote: > On Tuesday 27 September 2005 20:52, Robin Lee Powell wrote: > > On Mon, Sep 26, 2005 at 09:30:53PM -0700, Robin Lee Powell > > wrote: > > > On Mon, Sep 26, 2005 at 09:13:15PM -0400, Jeff Dike wrote: > > > > On Mon, Sep 26, 2005 at 05:24:30PM -0700, Robin Lee Powell > > > > > wrote: > > > > > However, as soon as I run sshd by any means, the guest > > > > > hangs. I have no idea what to do about this. Help? > > > > > Are you sure the guest hangs? I.e. you can't ping it any > > > > more, consoles freeze, etc? > > > > Exactly that, yes. I've never let it go more than a few > > > minutes. > > > > > If so, then information like the version and a stack trace > > > > would be good. > > > > Debian unstable; 2.4.26-3um-1 > > Ah, they went to -3um, at least... however, you'd probably better > try 2.4.28-bs2 from my homepage (applied on latest 2.4, i.e. > 2.4.31) After several hours of trying, I couldn't get it to compile. If you can provide me with built kernels, I'd be happy to host them. > > > Started with the Debian-3.0r2.ext2 image, which I haven't done > > > much with. I can post my exact procedure if you like. > > > It's not just sshd, it turns out; just happened during a rather > > massive apt-get: > > > Get:51 http://http.us.debian.org stable/main exim 3.36-16 [759kB] > > Fetched 15.3MB in 30m3s (8507B/s) > > Preconfiguring packages ... > I.e. it went to Sarge, right? Right. > Ok, I'd first check the /lib/tls issue (shouldn't happen with 2.4 > guests, but still check) and the "upgrade UML" thing. I'll try the tls thing. -Robin -- http://www.digitalkingdom.org/~rlpowell/ *** http://www.lojban.org/ Reason #237 To Learn Lojban: "Homonyms: Their Grate!" Proud Supporter of the Singularity Institute - http://singinst.org/ |