2022-08-01 03:06:47

by Florian Fainelli

Subject: [PATCH] libbpf: Initialize err in probe_map_create

GCC-11 warns about the possibly unitialized err variable in
probe_map_create:

libbpf_probes.c: In function 'probe_map_create':
libbpf_probes.c:361:38: error: 'err' may be used uninitialized in this function [-Werror=maybe-uninitialized]
361 | return fd < 0 && err == exp_err ? 1 : 0;
| ~~~~^~~~~~~~~~

Fixes: 878d8def0603 ("libbpf: Rework feature-probing APIs")
Signed-off-by: Florian Fainelli <[email protected]>
---
tools/lib/bpf/libbpf_probes.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/lib/bpf/libbpf_probes.c b/tools/lib/bpf/libbpf_probes.c
index 97b06cede56f..6cf44e61815d 100644
--- a/tools/lib/bpf/libbpf_probes.c
+++ b/tools/lib/bpf/libbpf_probes.c
@@ -247,7 +247,7 @@ static int probe_map_create(enum bpf_map_type map_type, __u32 ifindex)
LIBBPF_OPTS(bpf_map_create_opts, opts);
int key_size, value_size, max_entries;
__u32 btf_key_type_id = 0, btf_value_type_id = 0;
- int fd = -1, btf_fd = -1, fd_inner = -1, exp_err = 0, err;
+ int fd = -1, btf_fd = -1, fd_inner = -1, exp_err = 0, err = 0;

opts.map_ifindex = ifindex;

--
2.25.1

2022-08-01 16:36:19

by Jiri Olsa

Subject: Re: [PATCH] libbpf: Initialize err in probe_map_create

On Sun, Jul 31, 2022 at 07:51:09PM -0700, Florian Fainelli wrote:
> GCC-11 warns about the possibly unitialized err variable in
> probe_map_create:
>
> libbpf_probes.c: In function 'probe_map_create':
> libbpf_probes.c:361:38: error: 'err' may be used uninitialized in this function [-Werror=maybe-uninitialized]
> 361 | return fd < 0 && err == exp_err ? 1 : 0;
> | ~~~~^~~~~~~~~~
>
> Fixes: 878d8def0603 ("libbpf: Rework feature-probing APIs")
> Signed-off-by: Florian Fainelli <[email protected]>

Acked-by: Jiri Olsa <[email protected]>

jirka

> ---
> tools/lib/bpf/libbpf_probes.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/tools/lib/bpf/libbpf_probes.c b/tools/lib/bpf/libbpf_probes.c
> index 97b06cede56f..6cf44e61815d 100644
> --- a/tools/lib/bpf/libbpf_probes.c
> +++ b/tools/lib/bpf/libbpf_probes.c
> @@ -247,7 +247,7 @@ static int probe_map_create(enum bpf_map_type map_type, __u32 ifindex)
> LIBBPF_OPTS(bpf_map_create_opts, opts);
> int key_size, value_size, max_entries;
> __u32 btf_key_type_id = 0, btf_value_type_id = 0;
> - int fd = -1, btf_fd = -1, fd_inner = -1, exp_err = 0, err;
> + int fd = -1, btf_fd = -1, fd_inner = -1, exp_err = 0, err = 0;
>
> opts.map_ifindex = ifindex;
>
> --
> 2.25.1
>

2022-08-04 22:11:20

by patchwork-bot+netdevbpf

Subject: Re: [PATCH] libbpf: Initialize err in probe_map_create

Hello:

This patch was applied to bpf/bpf-next.git (master)
by Andrii Nakryiko <[email protected]>:

On Sun, 31 Jul 2022 19:51:09 -0700 you wrote:
> GCC-11 warns about the possibly unitialized err variable in
> probe_map_create:
>
> libbpf_probes.c: In function 'probe_map_create':
> libbpf_probes.c:361:38: error: 'err' may be used uninitialized in this function [-Werror=maybe-uninitialized]
> 361 | return fd < 0 && err == exp_err ? 1 : 0;
> | ~~~~^~~~~~~~~~
>
> [...]

Here is the summary with links:
- libbpf: Initialize err in probe_map_create
https://git.kernel.org/bpf/bpf-next/c/3045f42a6432

You are awesome, thank you!
--
Deet-doot-dot, I am a bot.
https://korg.docs.kernel.org/patchwork/pwbot.html

2022-08-31 23:09:25

by Florian Fainelli

Subject: Re: [PATCH] libbpf: Initialize err in probe_map_create

On 8/4/2022 2:50 PM, [email protected] wrote:
> Hello:
>
> This patch was applied to bpf/bpf-next.git (master)
> by Andrii Nakryiko <[email protected]>:
>
> On Sun, 31 Jul 2022 19:51:09 -0700 you wrote:
>> GCC-11 warns about the possibly unitialized err variable in
>> probe_map_create:
>>
>> libbpf_probes.c: In function 'probe_map_create':
>> libbpf_probes.c:361:38: error: 'err' may be used uninitialized in this function [-Werror=maybe-uninitialized]
>> 361 | return fd < 0 && err == exp_err ? 1 : 0;
>> | ~~~~^~~~~~~~~~
>>
>> [...]
>
> Here is the summary with links:
> - libbpf: Initialize err in probe_map_create
> https://git.kernel.org/bpf/bpf-next/c/3045f42a6432
>
> You are awesome, thank you!

Thanks for applying, I was sort of expecting this patch to land to Linus
a bit quicker, as far as I can see it is still only in linux-next yet it
does fix a build warning turned error. Any chance of fast tracking it?

Thanks!
--
Florian