diff options
Diffstat (limited to 'stap.1.in')
| -rw-r--r-- | stap.1.in | 27 |
1 files changed, 26 insertions, 1 deletions
@@ -100,6 +100,10 @@ section for details. Add the given directory to the tapset search directory. See the description of pass 2 for details. .TP +.BI \-D " NAME=VALUE" +Add the given preprocessor directive to the module Makefile. These can +be used to override limit parameters described below. +.TP .BI \-R " DIR" Look for the systemtap runtime sources in the given directory. .TP @@ -471,7 +475,6 @@ See the .IR stapex (5) manual page for a collection of samples. - .SH SAFETY AND SECURITY Systemtap is an administrative tool. It exposes kernel internal data structures and potentially private user information. It acquires root @@ -497,6 +500,28 @@ against manipulation by concurrent probe handlers. Use of guru mode constructs such as embedded C can violate these constraints, leading to kernel crash or data corruption. .PP +The resource use limits are set by macros in the generated C code. +These may be overridden with the +.R -D +flag. A selection of these is as follows: +.TP +MAXNESTING +Maximum number of recursive function call levels. +.TP +MAXSTRINGLEN +Maximum length of strings. +.TP +MAXTRYLOCK +Maximum number of iterations to wait for locks on global variables +before declaring possible deadlock. +.TP +MAXACTION +Maximum number of statements to execute during any single probe hit. +.TP +MAXMAPENTRIES +Maximum number of rows in any single global array. + +.PP In case something goes wrong with .IR stap " or " stpd after a probe has already started running, one may safely kill both |