For cases like IPv6 addresses, having a means to supply tracing predicates for fields with more than 8 bytes would be convenient. This series provides a simple way to support this by allowing simple ==, != memory comparison with the predicate supplied when the size of the field exceeds 8 bytes. For example, to trace ::1, the predicate
"dst == 0x00000000000000000000000000000001"
..could be used.
Patch 1 provides the support for > 8 byte fields via a memcmp()-style predicate. Patch 2 adds tests for filter predicates, and patch 3 documents the fact that for > 8 bytes. only == and != are supported.
Changes since RFC [1]:
- originally a fix was intermixed with the new functionality as patch 1 in series [1]; the fix landed separately - small tweaks to how filter predicates are defined via fn_num as opposed to via fn directly
[1] https://lore.kernel.org/lkml/1659910883-18223-1-git-send-email-alan.maguire@...
Alan Maguire (3): tracing: support > 8 byte array filter predicates selftests/ftrace: add test coverage for filter predicates tracing: document > 8 byte numeric filtering support
Documentation/trace/events.rst | 9 +++ kernel/trace/trace_events_filter.c | 55 +++++++++++++++- .../selftests/ftrace/test.d/event/filter.tc | 62 +++++++++++++++++++ 3 files changed, 125 insertions(+), 1 deletion(-) create mode 100644 tools/testing/selftests/ftrace/test.d/event/filter.tc