On Tue, 25 Apr 2023 10:16:34 +0100 Alan Maguire <alan.maguire@xxxxxxxxxx> wrote: > 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. Nice! And I also would like to use something like "dst == ipv6(::1)" because it seems easy to make a mistake on the number of zeros. Can we add such type casting feature to the filter? Thank you, > > 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@xxxxxxxxxx/ > > 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 > > -- > 2.31.1 > -- Masami Hiramatsu (Google) <mhiramat@xxxxxxxxxx>
