From: Steven Rostedt <rostedt@goodmis.org>
To: "Masami Hiramatsu (Google)" <mhiramat@kernel.org>
Cc: linux-trace-kernel@vger.kernel.org, linux-kernel@vger.kernel.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
Date: Mon, 17 Jul 2023 19:51:29 -0400 [thread overview]
Message-ID: <20230717195129.14759151@gandalf.local.home> (raw)
In-Reply-To: <20230718084634.7746b16b470f5fa1b0d99521@kernel.org>
On Tue, 18 Jul 2023 08:46:34 +0900
Masami Hiramatsu (Google) <mhiramat@kernel.org> wrote:
> > > + * Get function parameter with the number of parameters.
> > > + * This can return NULL if the function has no parameters.
> >
> > " It can return EINVAL if this function's parameters are NULL."
>
> No, as you can see the code, if btf_type_vlen(func_proto) returns 0 (means
> the function proto type has no parameters), btf_get_func_param() returns
> NULL. This is important point because user needs to use IS_ERR_OR_NULL(ret)
> instead of IS_ERR(ret).
I didn't mean to replace what you had, I meant you left that part out. In
other words, you have to check for IS_ERR_OR_NULL(ret), not just "!ret".
-- Steve
> >
> > > + */
> > > +const struct btf_param *btf_get_func_param(const struct btf_type *func_proto, s32 *nr)
> > > +{
> > > + if (!func_proto || !nr)
> > > + return ERR_PTR(-EINVAL);
> > > +
next prev parent reply other threads:[~2023-07-17 23:51 UTC|newest]
Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-07-17 15:23 [PATCH v2 0/9] tracing: Improbe BTF support on probe events Masami Hiramatsu (Google)
2023-07-17 15:23 ` [PATCH v2 1/9] tracing/probes: Fix to add NULL check for BTF APIs Masami Hiramatsu (Google)
2023-07-17 15:23 ` [PATCH v2 2/9] bpf/btf: tracing: Move finding func-proto API and getting func-param API to BTF Masami Hiramatsu (Google)
2023-07-17 18:39 ` Steven Rostedt
2023-07-17 23:46 ` Masami Hiramatsu
2023-07-17 23:51 ` Alexei Starovoitov
2023-07-18 1:03 ` Masami Hiramatsu
2023-07-17 23:51 ` Steven Rostedt [this message]
2023-07-18 1:02 ` Masami Hiramatsu
2023-07-18 2:40 ` Donglin Peng
2023-07-18 10:44 ` Masami Hiramatsu
2023-07-18 13:56 ` Masami Hiramatsu
2023-07-18 17:11 ` Alexei Starovoitov
2023-07-18 23:03 ` Masami Hiramatsu
2023-07-18 23:12 ` Alexei Starovoitov
2023-07-19 15:17 ` Masami Hiramatsu
2023-07-19 2:09 ` Donglin Peng
2023-07-19 15:15 ` Masami Hiramatsu
2023-07-19 12:36 ` Alan Maguire
2023-07-19 15:24 ` Masami Hiramatsu
2023-07-19 15:49 ` Alan Maguire
2023-07-17 15:23 ` [PATCH v2 3/9] bpf/btf: Add a function to search a member of a struct/union Masami Hiramatsu (Google)
2023-07-20 22:34 ` Alan Maguire
2023-07-21 14:22 ` Masami Hiramatsu
2023-07-17 15:23 ` [PATCH v2 4/9] tracing/probes: Support BTF based data structure field access Masami Hiramatsu (Google)
2023-07-20 22:51 ` Alan Maguire
2023-07-21 14:22 ` Masami Hiramatsu
2023-07-17 15:24 ` [PATCH v2 5/9] tracing/probes: Support BTF field access from $retval Masami Hiramatsu (Google)
2023-07-17 15:24 ` [PATCH v2 6/9] tracing/probes: Add string type check with BTF Masami Hiramatsu (Google)
2023-07-17 15:24 ` [PATCH v2 7/9] tracing/fprobe-event: Assume fprobe is a return event by $retval Masami Hiramatsu (Google)
2023-07-17 15:24 ` [PATCH v2 8/9] selftests/ftrace: Add BTF fields access testcases Masami Hiramatsu (Google)
2023-07-20 23:00 ` Alan Maguire
2023-07-21 1:42 ` Masami Hiramatsu
2023-07-17 15:24 ` [PATCH v2 9/9] Documentation: tracing: Update fprobe event example with BTF field Masami Hiramatsu (Google)
2023-07-20 22:53 ` Alan Maguire
2023-07-21 13:58 ` Masami Hiramatsu
2023-07-19 9:02 ` [PATCH v2 0/9] tracing: Improbe BTF support on probe events Alan Maguire
2023-07-19 16:01 ` Masami Hiramatsu
2023-07-20 21:50 ` Alan Maguire
2023-07-25 23:45 ` Masami Hiramatsu
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