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Diffstat (limited to 'tapsets/contextinfo/contextinfo.txt')
| -rw-r--r-- | tapsets/contextinfo/contextinfo.txt | 72 |
1 files changed, 0 insertions, 72 deletions
diff --git a/tapsets/contextinfo/contextinfo.txt b/tapsets/contextinfo/contextinfo.txt deleted file mode 100644 index 5f7f725f..00000000 --- a/tapsets/contextinfo/contextinfo.txt +++ /dev/null @@ -1,72 +0,0 @@ -* Application name: probe context information ariables -* Contact: fche -* Motivation: let probes know where/how they were fired; introspective - probe handlers -* Background: discussions on mailing lists -* Target software: various -* Type of description: tapset variables -* Interesting probe points: n/a -* Interesting values: - - $pp_alias: string: the string specification of the probe point, as found - in the original .stp file, before alias and other - expansion - $pp: string: representation of this probe point, after alias and wildcard - expansion - $pp_function: string: source function (if available) - $pp_srcfile: string: source file name (if available) - $pp_srcline: number: line number in source file (if available) - - $function[pc]: string: function name containing given address - $module[pc]: string: kernel module name containing given address - $address[sym]: number: base address of given function symbol - - $pc: number: PC snapshot at invocation - $stack[depth]: number: PC of caller at given depth, if available - - $pid, $tgid, $uid, $comm : number/string : current-> fields - -* Dependencies: - - Debug-info files - -* Restrictions: - - The $pp series of variables are computed at translation time, and thus - are only applicable to those probes that have related debug-info points. - - $pc should be directly available. - - The $function series of read-only pseudo-arrays are calculated at - run time, from symbol table information passed in some way. - $stack[0] might take some probing in the registers, or (eek!) on the - target stack frame. Conservatively returning 0 instead may be okay. - - The current-based series of values ($pid etc.), for kernel-targeted - probes, need to check for !in_interrupt() before dereferencing current->. - -* Data collection: - - Several of the variables are translation-time constants, so these don't - have run-time collection needs. - - For a kernel/module probe, $function[] could be computed from the kallsyms - lookup functions. Alternately, the translator could emit a copy of the - target symbol table into the probe C code, which $function[] could - search. The $stack[] elements would be served by the runtime on a - best-effort basis. - -* Data presentation: - - n/a: variables are simple - -* Competition: - - unknown - -* Cross-references: - - http://sources.redhat.com/ml/systemtap/2005-q2/msg00395.html - http://sources.redhat.com/ml/systemtap/2005-q2/msg00281.html - -* Associated files: |