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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 [email protected].
This page was obtained from the project's upstream Git repository
⟨git://sourceware.org/git/systemtap.git⟩ on 2024-06-14. (At that
time, the date of the most recent commit that was found in the
repository was 2024-06-13.) If you discover any rendering
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(which is not part of the original manual page), send a mail to
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ERROR::FAULT(7stap)
Pages that refer to this page: stapprobes(3stap), error::pass5(7stap)