systemtap reports error 'Build-id mismatch'

[visual2me]

My desktop runs Ubuntu precise with linux kernel 3.2.0-24-generic-pae (i686), and I have installed the relevant linux-image-$(uname -r)-dbgsym package from the ddebs repository.

When I run the command "sudo stap --vp 00001 -e 'probe vfs.read { print("hello from read\n"); exit()}'" in bash, it finally gets an error in Pass 5, saying "ERROR: Build-id mismatch: "kernel" vs. "vmlinux-3.2.0-24-generic-pae" byte 0 (0x54 vs 0xc9) address 0xc15b0850 rc 0".

Then I check the vmlinux-3.2.0-24-generic-pae file with the command "readelf -x .notes /usr/lib/debug/boot/vmlinux-3.2.0-24-generic-pae", which shows the value at the address 0xc15b0850 is 0x54. Seems this value (build-id) in vmlinux-3.2.0-24-generic-pae is not equal to that in the running kernel.

BTW, when I try to run "sudo stap --vp 00001 -e 'probe vfs.read { print("hello from read\n"); exit()}'", it generates lots of WARNINGS, saying "WARNING: cannot find module sunrpc debuginfo: No DWARF information found" and "WARNING: cannot find module nfs debuginfo: No DWARF information found". Even after I setup the .debug-id folder under /usr/lib/debug/ as the instructions at http://sourceware.org/systemtap/wiki/SystemtapOnUbuntu, the WARNINGs remain. Seems systemtap doesn't look for the module debug info from /usr/lib/debug/ directory.

[Timo Juhani Lindfors (timo-lindfors)]

I'm trying to improve the error messages. Can you please tell me what the output of

http://lindi.iki.fi/lindi/systemtap/diagnose-error-cases.bash

is on your system?

[visual2me (visual2me)]

the output of the script is as below,

Package linux-image-3.2.0-24-generic-pae-dbgsym version 3.2.0-24.38 does not match version of currently running kernel: 3.2.0-24.37

It does not match! But how can I upgrade the running kernel from 3.2.0-24.37 to 3.2.0-24.38?

[Timo Juhani Lindfors (timo-lindfors)]

You have upgraded your kernel but not yet rebooted to this new version. Just reboot?

[visual2me (visual2me)]

Just after I installed the new Ubuntu precise, I upgraded the kernel from 3.2.0-23 to 3.2.0-24 and rebooted the machine. And 'uname -r' also shows it's running 3.2.0-24 now.

But what's strange is that 'uname -a' shows it's "... 3.2.0-24-generic-pae #37-Ubuntu ...", but the dbgsym package is 3.2.0-24-38. Seems these two packages don't match~~

[Timo Juhani Lindfors (timo-lindfors)]

"3.2.0-24" is not the full version number. You can see the version number of your linux packages using e.g.

dpkg -l | grep linux-image

[visual2me (visual2me)]

the output is
ii linux-image-3.2.0-24-generic-pae 3.2.0-24.37 Linux kernel image for version 3.2.0 on 64 bit x86 SMP
ii linux-image-3.2.0-24-generic-pae-dbgsym 3.2.0-24.38 Linux kernel debug image for version 3.2.0 on 64 bit x86 SMP
ii linux-image-generic-pae 3.2.0.24.26 Generic Linux kernel image

But I can't find linux-image-3.2.0-24-generic-pae of version 3.2.0-24.38 in the repository.

[Timo Juhani Lindfors (timo-lindfors)]

ftp://ftp.ubuntu.com/ubuntu/pool/main/l/linux/linux-image-3.2.0-24-generic-pae_3.2.0-24.38_i386.deb

?

[visual2me (visual2me)]

With web browser, I can see both the two packages, i.e. linux-image-3.2.0-24-generic-pae_3.2.0-24.37_i386.deb and linux-image-3.2.0-24-generic-pae_3.2.0-24.38_i386.deb, But why only the first one is visible in aptitude?

[visual2me (visual2me)]

I download the deb package linux-image-3.2.0-24-generic-pae_3.2.0-24.38_i386.deb from the server and install it manually with 'dpkg -i', then systemtap works. No idea why apt-get or aptitude or synaptic can't see and install the kernel of this release...

[Timo Juhani Lindfors (timo-lindfors)]

Are you sure you did aptitude update? Which mirror are you using?

[visual2me (visual2me)]

Sure, I run 'apt-get autoclean' and 'apt-get update' for several times, and I also switch several mirrors, including China, US, and the main server.

[Timo Juhani Lindfors (timo-lindfors)]

Can you try

apt-cache policy linux-image-3.2.0-24-generic-pae

?

[visual2me (visual2me)]

the output:

linux-image-3.2.0-24-generic-pae:
  Installed: 3.2.0-24.38
  Candidate: 3.2.0-24.38
  Version table:
 *** 3.2.0-24.38 0
        100 /var/lib/dpkg/status
     3.2.0-24.37 0
        500 http://us.archive.ubuntu.com/ubuntu/ precise-updates/main i386 Packages

[Timo Juhani Lindfors (timo-lindfors)]

Ok so it indeed still shows 3.2.0-24.37 for the us.archive.ubuntu.com mirror. Unfortunately I have no idea why :(

Anyways, this is definitely not a bug in systemtap.

[visual2me (visual2me)]

Thank you all the same. I agree that this is not a bug in systemtap.

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Timo Juhani Lindfors (timo-lindfors)]

Closing as INVALID since in comment #14 and #15 we agreed that the bug is not in systemtap.