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Diffstat (limited to 'Documentation/trace/kprobetrace.rst')
| -rw-r--r-- | Documentation/trace/kprobetrace.rst | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/Documentation/trace/kprobetrace.rst b/Documentation/trace/kprobetrace.rst index bf9cecb69fc9..a49662ccd53c 100644 --- a/Documentation/trace/kprobetrace.rst +++ b/Documentation/trace/kprobetrace.rst @@ -70,6 +70,15 @@ Synopsis of kprobe_events (\*3) this is useful for fetching a field of data structures. (\*4) "u" means user-space dereference. See :ref:`user_mem_access`. +Function arguments at kretprobe +------------------------------- +Function arguments can be accessed at kretprobe using $arg<N> fetcharg. This +is useful to record the function parameter and return value at once, and +trace the difference of structure fields (for debuging a function whether it +correctly updates the given data structure or not). +See the :ref:`sample<fprobetrace_exit_args_sample>` in fprobe event for how +it works. + .. _kprobetrace_types: Types |