1ERROR::PASS5(7stap) ERROR::PASS5(7stap)
2
6 error::pass5 - systemtap pass-5 errors
7
10 Errors that occur during pass 5 (execution) can have a variety of
11 causes.
12 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.
23 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.
35 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.
42 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.
51 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.
60 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.
66 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.
70 errors from target program
73 The program invoked by the stap -c CMD option may exit with a
74 non-zero code.
75 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.
83
87 Increasing the verbosity of pass-5 with an option such as --vp 00001
88 can help pinpoint the problem.
89
92 stap(1),
93 http://sourceware.org/systemtap/wiki/TipExhaustedResourceErrors,
94 error::fault(7stap),
95 error::reporting(7stap)
96 ERROR::PASS5(7stap)