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);
 	}
 
 	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

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
>