Re: [PATCH bpf-next v4 0/3] add support for writable bare tracepoint

[Hou Tao <houtao1@huawei.com>]

Oops, I mistakenly send out the zero-patch again. Sorry for that.

On 9/30/2021 5:13 PM, Hou Tao wrote:
> Hi,
>
> The patchset series supports writable context for bare tracepoint.
>
> The main idea comes from patchset "writable contexts for bpf raw
> tracepoints" [1], but it only supports normal tracepoint with
> associated trace event under tracefs. Now we have one use case
> in which we will add bare tracepoint in VFS layer, and update
> file::f_mode for specific files. The reason using bare tracepoint
> is that it doesn't form a ABI and we can change it freely. So
> add support for it in BPF.
>
> Comments are always welcome.
>
> [1]: https://lore.kernel.org/lkml/20190426184951.21812-1-mmullins@fb.com
>
> Change log:
> v4:
>  * rebased on bpf-next
>  * patch 2 is updated to add support for writable raw tracepoint
>    attachment in attach_raw_tp().
>
> v3: https://www.spinics.net/lists/bpf/msg46824.html
>   * use raw_tp.w instead of raw_tp_writable as section
>     name of writable tp
>   * use ASSERT_XXX() instead of CHECK()
>   * define a common macro for "/sys/kernel/bpf_testmod"
>
> v2: https://www.spinics.net/lists/bpf/msg46356.html 
>   * rebase on bpf-next tree
>   * address comments from Yonghong Song
>   * rename bpf_testmode_test_writable_ctx::ret as early_ret to reflect
>     its purpose better.
>
> v1: https://www.spinics.net/lists/bpf/msg46221.html
>
> Hou Tao (3):
>   bpf: support writable context for bare tracepoint
>   libbpf: support detecting and attaching of writable tracepoint program
>   bpf/selftests: add test for writable bare tracepoint
>
>  include/trace/bpf_probe.h                     | 19 +++++++---
>  tools/lib/bpf/libbpf.c                        | 21 ++++++++---
>  .../bpf/bpf_testmod/bpf_testmod-events.h      | 15 ++++++++
>  .../selftests/bpf/bpf_testmod/bpf_testmod.c   | 10 ++++++
>  .../selftests/bpf/bpf_testmod/bpf_testmod.h   |  5 +++
>  .../selftests/bpf/prog_tests/module_attach.c  | 35 +++++++++++++++++++
>  .../selftests/bpf/progs/test_module_attach.c  | 14 ++++++++
>  tools/testing/selftests/bpf/test_progs.c      |  4 +--
>  tools/testing/selftests/bpf/test_progs.h      |  2 ++
>  9 files changed, 114 insertions(+), 11 deletions(-)
>