Re: [RFC PATCH] Series short description

From: Masami Hiramatsu
Date: Thu Sep 23 2021 - 08:41:38 EST


Oops, ignore this. I forgot to update subjects.

On Thu, 23 Sep 2021 21:38:55 +0900
Masami Hiramatsu <mhiramat@xxxxxxxxxx> wrote:

> Hi Steve,
>
> Here I share my testing patch of the BTF for kprobe events.
> Currently this only allow user to specify '$$args' for
> tracing all arguments of the function. This is only
> avaialbe if
> - the probe point is on the function entry
> - the kernel is compiled with BTF (CONFIG_DEBUG_INFO_BTF)
> - the kernel is enables BPF (CONFIG_BPF_SYSCALL)
>
> And Special thanks to Sven! Most of BTF handling part of
> this patch comes from his patch [1]
>
> [1] https://stackframe.org/0001-ftrace-arg-hack.patch
>
> What I thought while coding this were;
> - kernel/bpf/btf.c can be moved under lib/ so that
> the other subsystems can reuse it, independent
> from BPF. (Also, this should depends on CONFIG_DEBUG_INFO_BTF)
> - some more utility functions can be exposed.
> e.g. I copied btf_type_int() from btf.c
> - If there are more comments for the BTF APIs, it will
> be more useful...
> - Overall, the BTF is easy to understand for who
> already understand DWARF. Great work!
> - I think I need 'ptr' and 'bool' types for fetcharg types.
>
> Anyway, this is just for testing. I have to add some
> more cleanup, features and documentations, etc.
>
> Thank you,
>
> ---
>
> Masami Hiramatsu (1):
> tracing/kprobe: Support $$args for function entry
>
>
> kernel/trace/trace_kprobe.c | 60 ++++++++++++++++++++++++-
> kernel/trace/trace_probe.c | 105 +++++++++++++++++++++++++++++++++++++++++++
> kernel/trace/trace_probe.h | 5 ++
> 3 files changed, 168 insertions(+), 2 deletions(-)
>
> --
> Masami Hiramatsu (Linaro) <mhiramat@xxxxxxxxxx>


--
Masami Hiramatsu <mhiramat@xxxxxxxxxx>