From: Jakub Kicinski <jakub.kicinski@netronome.com>
To: Jiri Olsa <jolsa@redhat.com>
Cc: Jiri Olsa <jolsa@kernel.org>, Alexei Starovoitov <ast@kernel.org>,
Daniel Borkmann <daniel@iogearbox.net>,
netdev@vger.kernel.org, bpf@vger.kernel.org,
Andrii Nakryiko <andriin@fb.com>, Yonghong Song <yhs@fb.com>,
Martin KaFai Lau <kafai@fb.com>
Subject: Re: [PATCH] bpftool: Try to read btf as raw data if elf read fails
Date: Mon, 21 Oct 2019 16:16:00 -0700 [thread overview]
Message-ID: <20191021161600.282c04fb@cakuba.netronome.com> (raw)
In-Reply-To: <20191021140227.GD32718@krava>
On Mon, 21 Oct 2019 16:02:27 +0200, Jiri Olsa wrote:
> > > static int do_dump(int argc, char **argv)
> > > {
> > > struct btf *btf = NULL;
> > > @@ -397,7 +429,7 @@ static int do_dump(int argc, char **argv)
> > > __u32 btf_id = -1;
> > > const char *src;
> > > int fd = -1;
> > > - int err;
> > > + int err = 0;
> >
> > This change looks unnecessary.
>
> I'm getting confusing warnings from gcc about this,
> but there is a code path where do_dump would return
> untouched err:
>
> do_dump
> int err;
>
> } else if (is_prefix(src, "file")) {
> btf = btf__parse_elf(*argv, NULL); // succeeds
>
> }
>
> while (argc) {
> if (is_prefix(*argv, "format")) {
> else { // in here
> goto done;
> }
>
> done:
> return err;
ugh, right those look legit, although unrelated to you change.
err should always be set before jumping to 'done'. The error
setting in this function looks super messy :( Sometimes is returns
errno codes, sometimes positive values, sometimes negative, sometimes
just -1. Sometimes it jumps to 'done' for no good reason, ahh :/
prev parent reply other threads:[~2019-10-21 23:16 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-10-18 10:34 [PATCH] bpftool: Try to read btf as raw data if elf read fails Jiri Olsa
2019-10-18 16:48 ` Andrii Nakryiko
2019-10-18 20:04 ` Yonghong Song
2019-10-21 13:55 ` Jiri Olsa
2019-10-21 13:54 ` Jiri Olsa
2019-10-18 22:39 ` Jakub Kicinski
2019-10-21 14:02 ` Jiri Olsa
2019-10-21 23:16 ` Jakub Kicinski [this message]
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