From: Andrii Nakryiko <andrii.nakryiko@gmail.com>
To: Alan Maguire <alan.maguire@oracle.com>
Cc: Alexei Starovoitov <ast@kernel.org>,
Daniel Borkmann <daniel@iogearbox.net>,
Andrii Nakryiko <andrii@kernel.org>, Martin Lau <kafai@fb.com>,
Song Liu <songliubraving@fb.com>, Yonghong Song <yhs@fb.com>,
john fastabend <john.fastabend@gmail.com>,
KP Singh <kpsingh@kernel.org>, Bill Wendling <morbo@google.com>,
Shuah Khan <shuah@kernel.org>, bpf <bpf@vger.kernel.org>,
Networking <netdev@vger.kernel.org>,
"open list:KERNEL SELFTEST FRAMEWORK"
<linux-kselftest@vger.kernel.org>,
open list <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH v2 bpf-next 3/3] libbpf: btf typed dump does not need to allocate dump data
Date: Fri, 16 Jul 2021 17:32:54 -0700 [thread overview]
Message-ID: <CAEf4BzbQKy=wuCnNBVPa+8HLkGWCYQ4nyPWMSW02=jnpNmOS6A@mail.gmail.com> (raw)
In-Reply-To: <1626475617-25984-4-git-send-email-alan.maguire@oracle.com>
On Fri, Jul 16, 2021 at 3:47 PM Alan Maguire <alan.maguire@oracle.com> wrote:
>
> By using the stack for this small structure, we avoid the need
> for freeing memory in error paths.
>
> Suggested-by: Andrii Nakryiko <andrii@kernel.org>
> Signed-off-by: Alan Maguire <alan.maguire@oracle.com>
> ---
> tools/lib/bpf/btf_dump.c | 5 ++---
> 1 file changed, 2 insertions(+), 3 deletions(-)
>
> diff --git a/tools/lib/bpf/btf_dump.c b/tools/lib/bpf/btf_dump.c
> index e5fbfb8..bd8e005 100644
> --- a/tools/lib/bpf/btf_dump.c
> +++ b/tools/lib/bpf/btf_dump.c
> @@ -2240,6 +2240,7 @@ int btf_dump__dump_type_data(struct btf_dump *d, __u32 id,
> const void *data, size_t data_sz,
> const struct btf_dump_type_data_opts *opts)
> {
> + struct btf_dump_data typed_dump = {};
> const struct btf_type *t;
> int ret;
>
> @@ -2250,7 +2251,7 @@ int btf_dump__dump_type_data(struct btf_dump *d, __u32 id,
> if (!t)
> return libbpf_err(-ENOENT);
>
> - d->typed_dump = calloc(1, sizeof(struct btf_dump_data));
> + d->typed_dump = &typed_dump;
> if (!d->typed_dump)
> return libbpf_err(-ENOMEM);
can't happen, removed, please pay attention to the surrounding code
>
> @@ -2269,7 +2270,5 @@ int btf_dump__dump_type_data(struct btf_dump *d, __u32 id,
>
> ret = btf_dump_dump_type_data(d, NULL, t, id, data, 0, 0);
>
> - free(d->typed_dump);
> -
added resetting to NULL here, so that we don't have an accidental
dangling pointers
> return libbpf_err(ret);
> }
> --
> 1.8.3.1
>
next prev parent reply other threads:[~2021-07-17 0:33 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-07-16 22:46 [PATCH v2 bpf-next 0/3] libbpf: BTF typed dump cleanups Alan Maguire
2021-07-16 22:46 ` [PATCH v2 bpf-next 1/3] libbpf: clarify/fix unaligned data issues for btf typed dump Alan Maguire
2021-07-17 0:32 ` Andrii Nakryiko
2021-07-16 22:46 ` [PATCH v2 bpf-next 2/3] libbpf: fix compilation errors on ppc64le for btf dump typed data Alan Maguire
2021-07-17 0:32 ` Andrii Nakryiko
2021-07-16 22:46 ` [PATCH v2 bpf-next 3/3] libbpf: btf typed dump does not need to allocate dump data Alan Maguire
2021-07-17 0:32 ` Andrii Nakryiko [this message]
2021-07-17 0:32 ` [PATCH v2 bpf-next 0/3] libbpf: BTF typed dump cleanups Andrii Nakryiko
2021-07-17 0:38 ` Andrii Nakryiko
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to='CAEf4BzbQKy=wuCnNBVPa+8HLkGWCYQ4nyPWMSW02=jnpNmOS6A@mail.gmail.com' \
--to=andrii.nakryiko@gmail.com \
--cc=alan.maguire@oracle.com \
--cc=andrii@kernel.org \
--cc=ast@kernel.org \
--cc=bpf@vger.kernel.org \
--cc=daniel@iogearbox.net \
--cc=john.fastabend@gmail.com \
--cc=kafai@fb.com \
--cc=kpsingh@kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-kselftest@vger.kernel.org \
--cc=morbo@google.com \
--cc=netdev@vger.kernel.org \
--cc=shuah@kernel.org \
--cc=songliubraving@fb.com \
--cc=yhs@fb.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).