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From:   Andrii Nakryiko <andrii.nakryiko@gmail.com>
Date:   Mon, 1 Nov 2021 16:47:42 -0700
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Subject: Re: [PATCH v7 07/11] tools/bpf/bpftool/skeleton: make it adopt to
 task comm size change
To:     Yafang Shao <laoar.shao@gmail.com>
Cc:     Andrew Morton <akpm@linux-foundation.org>,
        Kees Cook <keescook@chromium.org>,
        Steven Rostedt <rostedt@goodmis.org>,
        Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
        Arnaldo Carvalho de Melo <arnaldo.melo@gmail.com>,
        Petr Mladek <pmladek@suse.com>,
        Peter Ziljstra <peterz@infradead.org>,
        Al Viro <viro@zeniv.linux.org.uk>,
        Valentin Schneider <valentin.schneider@arm.com>,
        Qiang Zhang <qiang.zhang@windriver.com>,
        robdclark <robdclark@chromium.org>,
        Christian Brauner <christian@brauner.io>,
        Dietmar Eggemann <dietmar.eggemann@arm.com>,
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        Vincent Guittot <vincent.guittot@linaro.org>,
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        Jakub Kicinski <kuba@kernel.org>,
        Alexei Starovoitov <ast@kernel.org>,
        Daniel Borkmann <daniel@iogearbox.net>,
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        john fastabend <john.fastabend@gmail.com>,
        KP Singh <kpsingh@kernel.org>,
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On Sun, Oct 31, 2021 at 11:04 PM Yafang Shao <laoar.shao@gmail.com> wrote:
>
> bpf_probe_read_kernel_str() will add a nul terminator to the dst, then
> we don't care about if the dst size is big enough.
>
> Signed-off-by: Yafang Shao <laoar.shao@gmail.com>
> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
> Cc: Arnaldo Carvalho de Melo <arnaldo.melo@gmail.com>
> Cc: Alexei Starovoitov <alexei.starovoitov@gmail.com>
> Cc: Andrii Nakryiko <andrii.nakryiko@gmail.com>
> Cc: Peter Zijlstra <peterz@infradead.org>
> Cc: Steven Rostedt <rostedt@goodmis.org>
> Cc: Al Viro <viro@zeniv.linux.org.uk>
> Cc: Kees Cook <keescook@chromium.org>
> Cc: Petr Mladek <pmladek@suse.com>
> ---

LGTM.

Acked-by: Andrii Nakryiko <andrii@kernel.org>

>  tools/bpf/bpftool/skeleton/pid_iter.bpf.c | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/tools/bpf/bpftool/skeleton/pid_iter.bpf.c b/tools/bpf/bpftool/skeleton/pid_iter.bpf.c
> index d9b420972934..f70702fcb224 100644
> --- a/tools/bpf/bpftool/skeleton/pid_iter.bpf.c
> +++ b/tools/bpf/bpftool/skeleton/pid_iter.bpf.c
> @@ -71,8 +71,8 @@ int iter(struct bpf_iter__task_file *ctx)
>
>         e.pid = task->tgid;
>         e.id = get_obj_id(file->private_data, obj_type);
> -       bpf_probe_read_kernel(&e.comm, sizeof(e.comm),
> -                             task->group_leader->comm);
> +       bpf_probe_read_kernel_str(&e.comm, sizeof(e.comm),
> +                                 task->group_leader->comm);
>         bpf_seq_write(ctx->meta->seq, &e, sizeof(e));
>
>         return 0;
> --
> 2.17.1
>