diff options
Diffstat (limited to 'stapprobes.5.in')
| -rw-r--r-- | stapprobes.5.in | 24 |
1 files changed, 17 insertions, 7 deletions
diff --git a/stapprobes.5.in b/stapprobes.5.in index 24075248..d20ea006 100644 --- a/stapprobes.5.in +++ b/stapprobes.5.in @@ -292,9 +292,10 @@ operators to match multiple names. The second part is optional and begins with the "@" character. It is followed by the path to the source file containing the function, which may include a wildcard pattern, such as mm/slab*. -In most cases, the path should be relative to the top of the -linux source directory, although an absolute path may be necessary for some kernels. -If a relative pathname doesn't work, try absolute. +If it does not match as is, an implicit "*/" is optionally added +.I before +the pattern, so that a script need only name the last few components +of a possibly long source directory path. .IP \(bu 4 Finally, the third part is optional if the file name part was given, and identifies the line number in the source file preceded by a ":" @@ -305,9 +306,16 @@ All the lines in the function can be matched with ":*". A range of lines x through y can be matched with ":x-y". .PP As an alternative, PATTERN may be a numeric constant, indicating an -(module-relative or kernel-_stext-relative) address. In guru mode -only, absolute kernel addresses may be specified with the ".absolute" -suffix. +address. Such an address may be found from symbol tables of the +appropriate kernel / module object file. It is verified against +known statement code boundaries, and will be relocated for use at +run time. +.PP +In guru mode only, absolute kernel-space addresses may be specified with +the ".absolute" suffix. Such an address is considered already relocated, +as if it came from +.BR /proc/kallsyms , +so it cannot be checked against statement/instruction boundaries. .PP Some of the source-level context variables, such as function parameters, locals, globals visible in the compilation unit, may be visible to @@ -412,7 +420,9 @@ probe gets called for every single step of the process described by PID or PATH. .PP Note that .I PATH -pathnames must be absolute. +names refer to executables that are searched the same way shells do: relative +to the working directory if they contain a "/" character, otherwise in +.BR $PATH . .SS PROCFS |