1ERROR::PASS5(7stap)                                        ERROR::PASS5(7stap)
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NAME

6       error::pass5 - systemtap pass-5 errors
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DESCRIPTION

10       Errors  that  occur  during  pass  5  (execution) can have a variety of
11       causes.
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14       exceptional events during script execution
15              The systemtap translator  and  runtime  include  numerous  error
16              checks  that  aim to protect the systems and the users from mis‐
17              takes or transient conditions.  The script may deliberately call
18              the  error()  tapset  function to signal a problem.  Some memory
19              needed for accessing $context variables may be  temporarily  un‐
20              available.   Consider  using  the  try/catch  construct  to wrap
21              script fragments in exception-handling code.  Consider using the
22              stap --suppress-handler-errors or stap --skip-badvars option.
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25       resource exhaustion
26              One of several types of space or time resource limits may be ex‐
27              ceeded by the script, including system overload, too many tuples
28              to be stored in an array, etc.  Some of the error messages iden‐
29              tify the constraint by macro name,  which  may  be  individually
30              raised.    Consider  using  the  stap  --suppress-handler-errors
31              and/or stap -g --suppress-time-limits options.  Extend  or  dis‐
32              able individual resource limits using the stap -DSOME_LIMIT=NNNN
33              option.  The stap -t option may identify those probes  that  are
34              taking too long.
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37       remote execution server problems
38              If you use the stap --remote option to direct a systemtap script
39              to be executed somewhere else, ensure that an SSH connection may
40              be  made to the remote host, and that it has the current system‐
41              tap runtime installed & available.
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44       installation/permission problems
45              It is possible that your copy of systemtap was not correctly in‐
46              stalled.  For example, the /usr/bin/staprun program may lack the
47              necessary setuid permissions, or your invoking userid might  not
48              have  sufficient  privileges (root, or stapusr and related group
49              memberships).  Environment variables may interfere with locating
50              /usr/libexec/.../stapio.
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53       security configuration
54              SecureBoot  or  other module signing machinery may be in effect,
55              preventing .ko module loading.  A local  or  remote  stap-server
56              service would be necessary to securely manage keys.  This situa‐
57              tion is detected automatically on most kernels, but on some, the
58              SYSTEMTAP_SIGN environment varible may have to be set to trigger
59              this extra signing-related processing.
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61              The normal kernel-module based systemtap  backend  may  be  more
62              than   your  script  requires.   Try  stap --runtime=bpf  and/or
63              stap --runtime=dyninst backends.  Though they have inherent lim‐
64              itations,  they  operate  with  lesser  privileges and perceived
65              risks.
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67              It may be possible to disable secure/lockdown measures temporar‐
68              ily   with   the   SysRQ+x   keystroke,   or   permanently  with
69              sudo mokutil --disable-validation and a reboot.
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72       errors from target program
73              The program invoked by the stap -c CMD option may  exit  with  a
74              non-zero code.
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77       uncaught exceptions in the target program
78              When  using  --runtime=dyninst  you may encounter an issue where
79              the target program aborts with a message like "terminate  called
80              after  throwing an instance of 'foo_exception'".  This is unfor‐
81              tunately a limitation of Dyninst, which sometimes  prevents  ex‐
82              ceptions from properly unwinding through instrumented code.
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GATHERING MORE INFORMATION

87       Increasing  the  verbosity  of pass-5 with an option such as --vp 00001
88       can help pinpoint the problem.
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SEE ALSO

92       stap(1),
93       http://sourceware.org/systemtap/wiki/TipExhaustedResourceErrors,
94       error::fault(7stap),
95       error::reporting(7stap)
96       warning::pass5(7stap)
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100                                                           ERROR::PASS5(7stap)
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