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NAME | DESCRIPTION | SEE ALSO | COLOPHON |
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ERROR::BUILDID(7stap) ERROR::BUILDID(7stap)
error::buildid - build-id verification failures
Because systemtap's script translation / execution stages may be
executed at different times and places, it is sometimes necessary to
verify certain invariants. One such invariant is that if a script
was informed by translate-time analysis of executables, then those
same executables need to be used at run time. This checking is done
based upon the build-id, a binary hash that modern (post-2007)
compilers/toolchains add as an NT_GNU_BUILD_ID ELF note to object
files and executables. Use the readelf -n command to examine the
build-ids of binaries, if you are interested.
Only scripts are sensitive to executables' build-ids: generally those
that perform deep analysis of the binaries or their debuginfo. For
example, scripts that place .function or .statement probes, or use
stack backtrace-related tapset functions may be sensitive. Other
scripts that rely only on process.mark or kernel.trace probes do not
require debuginfo. See the DWARF DEBUGINFO section in the
stapprobes(3stap) man page.
During translation, systemtap saves a copy of the relevant files'
build-ids within the compiled modules. At run-time, the modules
compare the saved ones to the actual run-time build-ids in memory.
The error message indicates that they did not match, so the module
will decline placing a probe that was computed based upon obsolete
data. This is important for safety, as placing them at an
inappropriate address could crash the programs. However, this is not
necessarily a fatal error, since probes unrelated to the mismatching
binaries may operate.
A build-id mismatch could be caused by a few different situations.
The main one is where the executable versions or architecture were
different between the systemtap translation and execution
times/places. For example, one may run a stap-server on a slightly
different version of the OS distribution. Someone may have rebuilt a
new kernel image, but preserved the previous version numbers. The
kernel running on the workstation may be slightly different from the
version being targeted - perhaps due to a pending kernel upgrade
leaving different files on disk versus running in memory. If your OS
distribution uses separate debuginfo packages, the split .debug files
may not exactly match the main binaries.
To disable build-id verification errors, if one is confident that
they are an artefact of build accidents rather than a real mismatch,
one might try the -DSTP_NO_BUILDID_CHECK option.
http://fedoraproject.org/wiki/Releases/FeatureBuildId ,
stap(1),
stapprobes(3stap),
warning::debuginfo(7stap),
error::reporting(7stap)
This page is part of the systemtap (a tracing and live-system
analysis tool) project. Information about the project can be found
at ⟨https://sourceware.org/systemtap/⟩. If you have a bug report for
this manual page, send it to systemtap@sourceware.org. This page was
obtained from the project's upstream Git repository
⟨git://sourceware.org/git/systemtap.git⟩ on 2018-02-02. (At that
time, the date of the most recent commit that was found in the repos‐
itory was 2018-02-01.) If you discover any rendering problems in
this HTML version of the page, or you believe there is a better or
more up-to-date source for the page, or you have corrections or
improvements to the information in this COLOPHON (which is not part
of the original manual page), send a mail to man-pages@man7.org
ERROR::BUILDID(7stap)
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