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ERROR::FAULT(7stap) ERROR::FAULT(7stap)
error::fault - memory access faults
Read or write faults can occur during the operation of a systemtap
script, if the script causes dereferencing of a pointer that turns
out to be invalid. This can be caused by using context variables
that do not happen to have valid values, or perhaps references to
memory that is unavailable at that moment due to paging.
These fault conditions are benign because they are caught by the
systemtap runtime, which cleanly terminates the script. If quick
termination is not desired, consider using the --skip-badvars or
--suppress-handler-errors or -DMAXERRORS=NN stap options, or
wrapping relevant parts of the probe handlers in a try/catch
block.
It may be possible to adjust the target program, to make it more
likely that needed context variables are paged in when systemtap
looks for them. Consider adding some lightweight processing on
the key variables, like a strlen(foo) for a string, or iterating
across elements of an array or linked list, or touching a few
bytes of a heap-allocated block. The idea is to trigger any page
faults in the target program, before systemtap would need to (but
can't).
stap(1),
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 2025-08-11. (At that
time, the date of the most recent commit that was found in the
repository was 2025-07-24.) 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::FAULT(7stap)
Pages that refer to this page: stapprobes(3stap), error::pass5(7stap)