By type - http://sourceware.org/systemtap/tutorial/node23.html This chapter explains the most common errors you may encounter while using SystemTap.

understanding SystemTap errors parse/semantics error errors parse/semantics error parse/semantics error understanding SystemTap errors These types of errors occur while SystemTap attempts to parse and translate the script into C, prior to being converted into a kernel module. For example type errors result from operations that assign invalid values to variables or arrays. understanding SystemTap errors parse/semantics error invalid values to variables/arrays errors parse/semantics error invalid values to variables/arrays parse/semantics error understanding SystemTap errors invalid values to variables/arrays invalid values to variables/arrays parse/semantics error understanding SystemTap errors understanding SystemTap errors parse/semantics error grammatical/typographical script error errors parse/semantics error grammatical/typographical script error parse/semantics error understanding SystemTap errors grammatical/typographical script error grammatical/typographical script error parse/semantics error understanding SystemTap errors typographical script error parse/semantics error understanding SystemTap errors The script contains a grammatical/typographical error. SystemTap detected type of construct that is incorrect, given the context of the probe. need more clarification (example) on this; could not replicate. how to replicate? The following invalid SystemTap script is missing its probe handlers: It results in the following error message showing that the parser was expecting something other than the probe keyword in column 1 of line 2: parse error: expected one of '. , ( ? ! { = +=' saw: keyword at perror.stp:2:1 1 parse error(s). understanding SystemTap errors parse/semantics error embedded code in unprivileged script errors parse/semantics error embedded code in unprivileged script parse/semantics error understanding SystemTap errors embedded code in unprivileged script embedded code in unprivileged script parse/semantics error understanding SystemTap errors unprivileged script, embedded code in parse/semantics error understanding SystemTap errors unsafe embedded code in unprivileged script parse/semantics error understanding SystemTap errors The script contains unsafe embedded C code (blocks of code surrounded by %{ %}. SystemTap allows you to embed C code in a script, which is useful if there are no tapsets to suit your purposes. However, embedded C constructs are not be safe; as such, SystemTap warns you with this error if such constructs appear in the script. understanding SystemTap errors parse/semantics error guru mode errors parse/semantics error guru mode parse/semantics error understanding SystemTap errors guru mode guru mode parse/semantics error understanding SystemTap errors If you are sure of the safety of any similar constructs in the script and are member of stapdev group (or have root privileges), run the script in "guru" mode by using the option -g (i.e. stap -g script). understanding SystemTap errors parse/semantics error type mismatch for identifier errors parse/semantics error type mismatch for identifier parse/semantics error understanding SystemTap errors type mismatch for identifier type mismatch for identifier parse/semantics error understanding SystemTap errors identifier type mismatch parse/semantics error understanding SystemTap errors The function foo in the script used the wrong type (i.e. %s or %d). This error will present itself in , because the function execname() returns a string the format specifier should be a %s, not %d. probe syscall.open { printf ("%d(%d) open\n", execname(), pid()) } understanding SystemTap errors parse/semantics error unresolved type for identifier errors parse/semantics error unresolved type for identifier parse/semantics error understanding SystemTap errors unresolved type for identifier unresolved type for identifier parse/semantics error understanding SystemTap errors The identifier (e.g. a variable) was used, but no type (integer or string) could be determined. This occurs, for instance, if you use a variable in a printf statement while the script never assigns a value to the variable. understanding SystemTap errors parse/semantics error expected symbol/array index expression errors parse/semantics error expected symbol/array index expression parse/semantics error understanding SystemTap errors expected symbol/array index expression expected symbol/array index expression parse/semantics error understanding SystemTap errors SystemTap could not assign a value to a variable or to a location in an array. The destination for the assignment is not a valid destination. The following example code would generate this error: understanding SystemTap errors parse/semantics error unresolved function call errors parse/semantics error unresolved function call parse/semantics error understanding SystemTap errors unresolved function call unresolved function call parse/semantics error understanding SystemTap errors function call (unresolved) parse/semantics error understanding SystemTap errors A function call or array index expression in the script used an invalid number of arguments/parameters. In SystemTap arity can either refer to the number of indices for an array, or the number of parameters to a function. array locals not supported parse/semantics error understanding SystemTap errors understanding SystemTap errors parse/semantics error non-global arrays errors parse/semantics error non-global arrays parse/semantics error understanding SystemTap errors non-global arrays non-global arrays parse/semantics error understanding SystemTap errors The script used an array operation without declaring the array as a global variable (global variables can be declared after their use in Systemtap scripts). Similar messages appear if an array is used, but with inconsistent arities. understanding SystemTap errors parse/semantics error variable modified during 'foreach' errors parse/semantics error variable modified during 'foreach' parse/semantics error understanding SystemTap errors variable modified during 'foreach' variable modified during 'foreach' parse/semantics error understanding SystemTap errors The array foo is being modifed (being assigned to or deleted from) within an active foreach loop. This error also displays if an operation within the script performs a function call within the foreach loop. understanding SystemTap errors parse/semantics error probe mismatch errors parse/semantics error probe mismatch parse/semantics error understanding SystemTap errors probe mismatch probe mismatch parse/semantics error understanding SystemTap errors SystemTap did not understand what the event or SystemTap function foo refers to. This usually means that SystemTap could not find a match for foo in the tapset library. The N refers to the line and column of the error. how to explain N in previous? "The divergence from the “tree” of probe point namespace is at position N (starting with zero at left)." (from tutorial) understanding SystemTap errors parse/semantics error no match for probe point errors parse/semantics error no match for probe point parse/semantics error understanding SystemTap errors no match for probe point no match for probe point parse/semantics error understanding SystemTap errors probe point (no match for) parse/semantics error understanding SystemTap errors The events / handler function foo could not be resolved altogether, for a variety of reasons. This error occurs when the script contains the event kernel.function("blah"), and blah does not exist. In some cases, the error could also mean the script contains an invalid kernel file name or source line number. understanding SystemTap errors parse/semantics error unresolved target-symbol expression errors parse/semantics error unresolved target-symbol expression parse/semantics error understanding SystemTap errors unresolved target-symbol expression unresolved target-symbol expression parse/semantics error understanding SystemTap errors target-symbol expression, unresolved parse/semantics error understanding SystemTap errors A handler in the script references a target variable, but the value of the variable could not be resolved. This error could also mean that a handler is referencing a target variable that is not valid in the context when it was referenced. This may be a result of compiler optimization of the generated code. understanding SystemTap errors parse/semantics error libdwfl failure errors parse/semantics error libdwfl failure parse/semantics error understanding SystemTap errors libdwfl failure libdwfl failure parse/semantics error understanding SystemTap errors There was a problem processing the debugging information. In most cases, this error results from the installation of a kernel-debuginfo RPM whose version does not match the probed kernel exactly. The installed kernel-debuginfo RPM itself may have some consistency / correctness problems. SystemTap could not find a suitable kernel-debuginfo at all.

understainding SystemTap errors runtime errors/warnings errors runtime errors/warnings runtime errors/warnings understainding SystemTap errors Runtime errors and warnings occur when the SystemTap instrumentation has been installed and is collecting data on the system. understainding SystemTap errors runtime errors/warnings number of errors: N, skipped probes: M errors runtime errors/warnings number of errors: N, skipped probes: M runtime errors/warnings understainding SystemTap errors number of errors: N, skipped probes: M number of errors: N, skipped probes: M runtime errors/warnings understainding SystemTap errors Errors and/or skipped probes occurred during this run. Both N and M are the counts of the number of probes that were not executed due to conditions such as too much time required to execute event handlers over an interval of time. understainding SystemTap errors runtime errors/warnings division by 0 errors runtime errors/warnings division by 0 runtime errors/warnings understainding SystemTap errors division by 0 division by 0 runtime errors/warnings understainding SystemTap errors invalid division runtime errors/warnings understainding SystemTap errors The script code performed an invalid division. understainding SystemTap errors runtime errors/warnings aggregate element not found errors runtime errors/warnings aggregate element not found runtime errors/warnings understainding SystemTap errors aggregate element not found aggregate element not found runtime errors/warnings understainding SystemTap errors An statistics extractor function other than @count was invoked on an aggregate that has not had any values accumulated yet. This is similar to a division by zero. understainding SystemTap errors runtime errors/warnings aggregation overflow errors runtime errors/warnings aggregation overflow runtime errors/warnings understainding SystemTap errors aggregation overflow aggregation overflow runtime errors/warnings understainding SystemTap errors overflow of aggregation runtime errors/warnings understainding SystemTap errors An array containing aggregate values contains too many distinct key pairs at this time. understainding SystemTap errors runtime errors/warnings MAXNESTING exceeded errors runtime errors/warnings MAXNESTING exceeded runtime errors/warnings understainding SystemTap errors MAXNESTING exceeded MAXNESTING exceeded runtime errors/warnings understainding SystemTap errors exceeded MAXNESTING runtime errors/warnings understainding SystemTap errors Too many levels of function call nesting were attempted. The default nesting of function calls allowed is 10. understainding SystemTap errors runtime errors/warnings MAXACTION exceeded errors runtime errors/warnings MAXACTION exceeded runtime errors/warnings understainding SystemTap errors MAXACTION exceeded MAXACTION exceeded runtime errors/warnings understainding SystemTap errors exceeded MAXACTION runtime errors/warnings understainding SystemTap errors The probe handler attempted to execute too many statements in the probe handler. The default number of actions allow in a probe handler is 1000. understainding SystemTap errors runtime errors/warnings copy fault errors runtime errors/warnings copy fault runtime errors/warnings understainding SystemTap errors copy fault copy fault runtime errors/warnings understainding SystemTap errors The probe handler attempted to copy a string from kernel or user space at an invalid address (ADDR). understainding SystemTap errors runtime errors/warnings pointer dereference fault errors runtime errors/warnings pointer dereference fault runtime errors/warnings understainding SystemTap errors pointer dereference fault pointer dereference fault runtime errors/warnings understainding SystemTap errors There was a fault encountered during a pointer dereference operation such as a target variable evaluation.