From: Jiri Olsa <olsajiri@gmail.com>
To: Li kunyu <kunyu@nfschina.com>
Cc: lkp@intel.com, andrii@kernel.org, ast@kernel.org,
bpf@vger.kernel.org, daniel@iogearbox.net, haoluo@google.com,
john.fastabend@gmail.com, kbuild-all@lists.01.org,
kpsingh@kernel.org, linux-kernel@vger.kernel.org,
martin.lau@linux.dev, sdf@google.com, song@kernel.org,
yhs@fb.com
Subject: Re: [PATCH] lib: bpf: Optimized variable usage in the btf_parse_elf function
Date: Sun, 9 Oct 2022 14:53:42 +0200 [thread overview]
Message-ID: <Y0LEVuvk/O93xBAn@krava> (raw)
In-Reply-To: <20221009070827.525694-2-kunyu@nfschina.com>
On Sun, Oct 09, 2022 at 03:08:28PM +0800, Li kunyu wrote:
> The following changes were made in the btf_parse_elf function:
> 1. The initialization assignments of err, fd, scn and elf variables are
> removed, and they do not affect function security after analysis.
> 2. Remove unnecessary assignments to err variable (-error).
>
> Signed-off-by: Li kunyu <kunyu@nfschina.com>
> ---
> tools/lib/bpf/btf.c | 11 ++++-------
> 1 file changed, 4 insertions(+), 7 deletions(-)
>
> diff --git a/tools/lib/bpf/btf.c b/tools/lib/bpf/btf.c
> index 2d14f1a52d7a..fa9d5fa03da4 100644
> --- a/tools/lib/bpf/btf.c
> +++ b/tools/lib/bpf/btf.c
> @@ -910,10 +910,10 @@ static struct btf *btf_parse_elf(const char *path, struct btf *base_btf,
> struct btf_ext **btf_ext)
> {
> Elf_Data *btf_data = NULL, *btf_ext_data = NULL;
> - int err = 0, fd = -1, idx = 0;
> + int err, fd, idx = 0;
> struct btf *btf = NULL;
> - Elf_Scn *scn = NULL;
> - Elf *elf = NULL;
> + Elf_Scn *scn;
> + Elf *elf;
> GElf_Ehdr ehdr;
> size_t shstrndx;
>
> @@ -924,9 +924,8 @@ static struct btf *btf_parse_elf(const char *path, struct btf *base_btf,
>
> fd = open(path, O_RDONLY | O_CLOEXEC);
> if (fd < 0) {
> - err = -errno;
> pr_warn("failed to open %s: %s\n", path, strerror(errno));
> - return ERR_PTR(err);
> + return ERR_PTR(-errno);
hum, pr_warn could potentionally change errno
jirka
> }
>
> err = -LIBBPF_ERRNO__FORMAT;
> @@ -987,8 +986,6 @@ static struct btf *btf_parse_elf(const char *path, struct btf *base_btf,
> }
> }
>
> - err = 0;
> -
> if (!btf_data) {
> err = -ENOENT;
> goto done;
> --
> 2.18.2
>
prev parent reply other threads:[~2022-10-09 12:53 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-10-08 8:21 [PATCH] lib: bpf: Optimized variable usage in the btf_parse_elf function Li kunyu
2022-10-08 11:06 ` kernel test robot
2022-10-08 12:30 ` kernel test robot
2022-10-09 7:08 ` Li kunyu
2022-10-09 12:53 ` Jiri Olsa [this message]
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