Debian unstable libc6 upgrade killed my system
I seem to have killed my system dead. fork() is forked.
simon@stout:~$ ls
-bash: ../nptl/sysdeps/unix/sysv/linux/fork.c:132: __libc_fork: Assertion `({ __typeof (self->tid) __value; if (sizeof (__value) == 1) asm volatile ("movb %%gs:%P2,%b0" : "=q" (__value) : "0" (0), "i" (((size_t) &((struct pthread *)0)->tid))); else if (sizeof (__value) == 4) asm volatile ("movl %%gs:%P1,%0" : "=r" (__value) : "i" (((size_t) &((struct pthread *)0)->tid))); else { if (sizeof (__value) != 8) abort (); asm volatile ("movl %%gs:%P1,%%eax\n\t" "movl %%gs:%P2,%%edx" : "=A" (__value) : "i" (((size_t) &((struct pthread *)0)->tid)), "i" (((size_t) &((struct pthread *)0)->tid) + 4)); } __value; }) != ppid' failed.
Aborted
I can ssh in and an existing mutt session seems to be able to run, including run sudo for root privs.
Any suggestions on recovery greatly appreciated.
Options I'm thinking are:
1. Unpack an older libc6 package somewhere else, scp it up and manually install all the bits. Cross fingers and hope it works. I'm not a C guru though, so mabye this is boneheaded thinking?
2. Purchase some more disk space temporarily and create a new partition. Boot from that, reinstall Debian on it, mount the old drive, copy data across. Then remove the temporarily added disk space (and stop paying for it)
Any more sensible suggestions greatly appreciated.
9 Replies
caker
Linode Staff
mv /lib/tls /lib/tls-disabled
After that, running an NPTL enabled libc under a 2.6-um kernel will work…
-Chris
Caker, could I ask you to work with Bruce Stephens <
@Shermozle:
Ouch. If you're running Debian unstable, be vewwy vewwy careful upgrading right now.
http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=265486 I seem to have killed my system dead. fork() is forked.
[snip]
Any more sensible suggestions greatly appreciated.
Did this show up in the apt-listbugs output when you did apt-get upgrade? I see that the bug report is only from today.
I run testing, and have seen some grave and some critical bugs reported by apt-listbugs, so I've held off upgrading perl, for example.
@caker:
Boot under a 2.4 based kernel, and then:
mv /lib/tls /lib/tls-disabledAfter that, running an NPTL enabled libc under a 2.6-um kernel will work…
Chris, can you explain (use small words and speak slowly for me) to me exactly what the problem here is? I can try and get some kind of check incorporated in the upgrade process of the Debian package.
The difference in the way the problem manifests itself (or not) between 2.4 and 2.6 is because NPTL enabled /lib/ld.so checks 'uname' in 2.4 kernels. If extraversion begins with "-ntpl" then this 2.4 kernel has NPTL (and TLS) support. If extraversion doesn't have that string, ld.so assumes that the kernel doesn't have NPTL (or TLS) support. If the kernel is >=2.6, then ld.so assumes that NPTL (and TLS) support is present, so things start to go haywire under UML, where this assumption is invalid.
and all was well, except I couldn't log in via ssh, so I also added:
devpts /dev/pts devpts defaults 0 0
to /etc/fstab (as per instructions I found on google).
There is no /lib/tls directory on a normal woody install, so caker's instructions don't seem to apply.
@Shermozle:
Chris, can you explain (use small words and speak slowly for me) to me exactly what the problem here is? I can try and get some kind of check incorporated in the upgrade process of the Debian package.
I wrote up a little howto and explanation of the whole /lib/tls thing: