Hi,
Here is the 11th version of series to introduce more typecast features
to probe events. The previous version is here:
https://lore.kernel.org/all/178243982430.790911.17439694390021542101.stgit@devnote2/
In this version, I fixed minor issues and add 2 patches to fix
in-tree tools to ignore comment lines in dynamic_events[3/11][4/11].
This series extends BTF typecast feature and add more options:
1. Expanding BTF typecast to kprobe and fprobe.
(currently only function entry/exit)
2. Introduce container_of like typecast. This adds a "assigned
member" option to the typecast.
(STRUCT,MEMBER)VAR->ANOTHER_MEMBER
This casts VAR to STRUCT type but the VAR is as the address
of STRUCT.MEMBER. In C, it is:
container_of(VAR, STRUCT, MEMBER)->ANOTHER_MEMBER
3. Support nested typecast, e.g.
(STRUCT)((STRUCT2)VAR->MEMBER2)->MEMBER
the nest level must be smaller than 3.
4. Add $current variable to point "current" task_struct.
This is useful with typecast, e.g.
(task_struct)$current->pid
5. per-cpu dereference support.
Intrdouce this_cpu_read(VAR) and this_cpu_ptr(VAR) to
access per-cpu data on the current CPU (accessing other CPU
data is not stable, because it can be changed.)
You can access the member of per-cpu data structure using
typecast like:
(STRUCT)this_cpu_ptr(VAR)->MEMBER
6. Support event fields without $ prefix on eprobes.
Now eprobe events can access its event fields.
And added fetcharg dump feature (for debug) and updated test scripts
to test part of them.
Thanks,
---
base-commit: c69b5f959286395e94c237ce6d7d4970bad7f6e3
Masami Hiramatsu (Google) (11):
tracing/probes: Allow eprobe to use variable without $ prefix
tracing/probes: Support dumping fetcharg program for debugging dynamic events
tools/bootconfig: Ignore comment lines in dynamic_events/kprobe_events file
perf/probe: Ignore comment lines in dynamic_events/kprobe_events file
tracing/probes: Support typecast for various probe events
tracing/probes: Support nested typecast
tracing/probes: Type casting always involves nested calls
tracing/probes: Support field specifier option for typecast
tracing/probes: Add $current variable support
tracing/probes: Add this_cpu_read() and this_cpu_ptr() dereference method to fetcharg
tracing/probes: Add a new testcase for BTF typecasts
Documentation/trace/eprobetrace.rst | 7
Documentation/trace/fprobetrace.rst | 10
Documentation/trace/kprobetrace.rst | 11
kernel/trace/Kconfig | 12
kernel/trace/trace.c | 8
kernel/trace/trace_eprobe.c | 2
kernel/trace/trace_fprobe.c | 2
kernel/trace/trace_kprobe.c | 2
kernel/trace/trace_probe.c | 585 ++++++++++++++++----
kernel/trace/trace_probe.h | 100 ++-
kernel/trace/trace_probe_tmpl.h | 25 +
kernel/trace/trace_uprobe.c | 3
samples/trace_events/trace-events-sample.c | 40 +
samples/trace_events/trace-events-sample.h | 34 +
tools/bootconfig/scripts/ftrace2bconf.sh | 2
tools/perf/util/probe-file.c | 2
.../ftrace/test.d/dynevent/btf_probe_event.tc | 51 ++
.../test.d/dynevent/btf_typecast_accepted.tc | 107 ++++
.../test.d/dynevent/eprobes_syntax_errors.tc | 12
.../ftrace/test.d/dynevent/fprobe_syntax_errors.tc | 12
.../ftrace/test.d/kprobe/kprobe_syntax_errors.tc | 12
.../ftrace/test.d/kprobe/uprobe_syntax_errors.tc | 5
22 files changed, 890 insertions(+), 154 deletions(-)
create mode 100644 tools/testing/selftests/ftrace/test.d/dynevent/btf_probe_event.tc
create mode 100644 tools/testing/selftests/ftrace/test.d/dynevent/btf_typecast_accepted.tc
--
Masami Hiramatsu (Google) <mhiramat@kernel.org>