Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 2620:137:e000::1:20 as permitted sender) client-ip=2620:137:e000::1:20;
Date:   Tue, 18 Jul 2023 22:56:06 +0900
From:   Masami Hiramatsu (Google) <mhiramat@kernel.org>
To:     Masami Hiramatsu (Google) <mhiramat@kernel.org>
Cc:     Donglin Peng <dolinux.peng@gmail.com>,
        linux-trace-kernel@vger.kernel.org, linux-kernel@vger.kernel.org,
        Steven Rostedt <rostedt@goodmis.org>,
        Martin KaFai Lau <martin.lau@linux.dev>, bpf@vger.kernel.org,
        Sven Schnelle <svens@linux.ibm.com>,
        Alexei Starovoitov <ast@kernel.org>
Subject: Re: [PATCH v2 2/9] bpf/btf: tracing: Move finding func-proto API
 and getting func-param API to BTF
Message-Id: <20230718225606.926222723cdd8c2c37294e41@kernel.org>
In-Reply-To: <20230718194431.5653b1e89841e6abd9742ede@kernel.org>
References: <168960739768.34107.15145201749042174448.stgit@devnote2>
        <168960741686.34107.6330273416064011062.stgit@devnote2>
        <CAErzpmuvhrj0HhTpH2m-C-=pFV=Q_mxYC59Hw=dm0pqUvtPm0g@mail.gmail.com>
        <20230718194431.5653b1e89841e6abd9742ede@kernel.org>
Mime-Version: 1.0
Content-Type: text/plain; charset=US-ASCII
Content-Transfer-Encoding: 7bit
Precedence: bulk

On Tue, 18 Jul 2023 19:44:31 +0900
Masami Hiramatsu (Google) <mhiramat@kernel.org> wrote:

> > >  static const struct btf_param *find_btf_func_param(const char *funcname, s32 *nr,
> > >                                                    bool tracepoint)
> > >  {
> > > +       struct btf *btf = traceprobe_get_btf();
> > 
> > I found that traceprobe_get_btf() only returns the vmlinux's btf. But
> > if the function is
> > defined in a kernel module, we should get the module's btf.
> > 
> 
> Good catch! That should be a separated fix (or improvement?)
> I think it's better to use btf_get() and btf_put(), and pass btf via
> traceprobe_parse_context.

Hmm, it seems that there is no exposed API to get the module's btf.
Should I use btf_idr and btf_idr_lock directly to find the corresponding
btf? If there isn't yet, I will add it too.

Thank you,

-- 
Masami Hiramatsu (Google) <mhiramat@kernel.org>