2020-07-15 04:11:13

by Yue Haibing

Subject: [PATCH] tools/bpftool: Fix error return code in do_skeleton()

The error return code should be PTR_ERR(obj) other than
PTR_ERR(NULL).

Fixes: 5dc7a8b21144 ("bpftool, selftests/bpf: Embed object file inside skeleton")
Signed-off-by: YueHaibing <[email protected]>
---
tools/bpf/bpftool/gen.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/tools/bpf/bpftool/gen.c b/tools/bpf/bpftool/gen.c
index 10de76b296ba..35f62273cdbd 100644
--- a/tools/bpf/bpftool/gen.c
+++ b/tools/bpf/bpftool/gen.c
@@ -305,8 +305,9 @@ static int do_skeleton(int argc, char **argv)
opts.object_name = obj_name;
obj = bpf_object__open_mem(obj_data, file_sz, &opts);
if (IS_ERR(obj)) {
+ err = PTR_ERR(obj);
+ p_err("failed to open BPF object file: %ld", err);
obj = NULL;
- p_err("failed to open BPF object file: %ld", PTR_ERR(obj));
goto out;
}

--
2.17.1

2020-07-15 16:51:47

by Quentin Monnet

Subject: Re: [PATCH] tools/bpftool: Fix error return code in do_skeleton()

2020-07-15 11:13 UTC+0800 ~ YueHaibing <[email protected]>
> The error return code should be PTR_ERR(obj) other than
> PTR_ERR(NULL).
>
> Fixes: 5dc7a8b21144 ("bpftool, selftests/bpf: Embed object file inside skeleton")
> Signed-off-by: YueHaibing <[email protected]>


Reviewed-by: Quentin Monnet <[email protected]>

Thanks!

2020-07-15 19:24:15

by Daniel Borkmann

Subject: Re: [PATCH] tools/bpftool: Fix error return code in do_skeleton()

On 7/15/20 5:13 AM, YueHaibing wrote:
> The error return code should be PTR_ERR(obj) other than
> PTR_ERR(NULL).
>
> Fixes: 5dc7a8b21144 ("bpftool, selftests/bpf: Embed object file inside skeleton")
> Signed-off-by: YueHaibing <[email protected]>
> ---
> tools/bpf/bpftool/gen.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/tools/bpf/bpftool/gen.c b/tools/bpf/bpftool/gen.c
> index 10de76b296ba..35f62273cdbd 100644
> --- a/tools/bpf/bpftool/gen.c
> +++ b/tools/bpf/bpftool/gen.c
> @@ -305,8 +305,9 @@ static int do_skeleton(int argc, char **argv)
> opts.object_name = obj_name;
> obj = bpf_object__open_mem(obj_data, file_sz, &opts);
> if (IS_ERR(obj)) {
> + err = PTR_ERR(obj);
> + p_err("failed to open BPF object file: %ld", err);
> obj = NULL;
> - p_err("failed to open BPF object file: %ld", PTR_ERR(obj));
> goto out;

Instead of just the error number, could we dump something useful to the user here
via libbpf_strerror() given you touch this line? Also, I think the convention in
do_skeleton() is to just return {0,-1} given this is propagated as return code
for bpftool.

> }
>
>

2020-07-17 12:32:13

by Yue Haibing

Subject: [PATCH v2] tools/bpftool: Fix error handing in do_skeleton()

Fix pass 0 to PTR_ERR, also dump more err info using
libbpf_strerror.

Fixes: 5dc7a8b21144 ("bpftool, selftests/bpf: Embed object file inside skeleton")
Signed-off-by: YueHaibing <[email protected]>
Reviewed-by: Quentin Monnet <[email protected]>
---
v2: use libbpf_strerror
---
tools/bpf/bpftool/gen.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/tools/bpf/bpftool/gen.c b/tools/bpf/bpftool/gen.c
index b59d26e89367..8a4c2b3b0cd6 100644
--- a/tools/bpf/bpftool/gen.c
+++ b/tools/bpf/bpftool/gen.c
@@ -302,8 +302,11 @@ static int do_skeleton(int argc, char **argv)
opts.object_name = obj_name;
obj = bpf_object__open_mem(obj_data, file_sz, &opts);
if (IS_ERR(obj)) {
+ char err_buf[256];
+
+ libbpf_strerror(PTR_ERR(obj), err_buf, sizeof(err_buf));
+ p_err("failed to open BPF object file: %s", err_buf);
obj = NULL;
- p_err("failed to open BPF object file: %ld", PTR_ERR(obj));
goto out;
}

--
2.17.1

2020-07-21 19:37:28

by Alexei Starovoitov

Subject: Re: [PATCH v2] tools/bpftool: Fix error handing in do_skeleton()

On Fri, Jul 17, 2020 at 5:31 AM YueHaibing <[email protected]> wrote:
>
> Fix pass 0 to PTR_ERR, also dump more err info using
> libbpf_strerror.
>
> Fixes: 5dc7a8b21144 ("bpftool, selftests/bpf: Embed object file inside skeleton")
> Signed-off-by: YueHaibing <[email protected]>
> Reviewed-by: Quentin Monnet <[email protected]>

Applied. Thanks