diff mbox series

[bpf] samples/bpf: Fix the error return code of xdp_redirect's main()

Message ID 20210616042534.315097-1-wanghai38@huawei.com (mailing list archive)
State Accepted
Commit 7c6090ee2a7b3315410cfc83a94c3eb057407b25
Delegated to: BPF
Headers show
Series [bpf] samples/bpf: Fix the error return code of xdp_redirect's main() | expand

Checks

Context Check Description
netdev/cover_letter success Link
netdev/fixes_present success Link
netdev/patch_count success Link
netdev/tree_selection success Clearly marked for bpf
netdev/subject_prefix success Link
netdev/cc_maintainers success CCed 13 of 13 maintainers
netdev/source_inline success Was 0 now: 0
netdev/verify_signedoff success Link
netdev/module_param success Was 0 now: 0
netdev/build_32bit success Errors and warnings before: 0 this patch: 0
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/verify_fixes success Link
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 6 lines checked
netdev/build_allmodconfig_warn success Errors and warnings before: 0 this patch: 0
netdev/header_inline success Link

Commit Message

wanghai (M) June 16, 2021, 4:25 a.m. UTC
Fix to return a negative error code from the error handling
case instead of 0, as done elsewhere in this function.

If bpf_map_update_elem() failed, main() should return a negative error.

Fixes: 832622e6bd18 ("xdp: sample program for new bpf_redirect helper")
Signed-off-by: Wang Hai <wanghai38@huawei.com>
---
 samples/bpf/xdp_redirect_user.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

Comments

patchwork-bot+netdevbpf@kernel.org June 18, 2021, 6:20 p.m. UTC | #1
Hello:

This patch was applied to bpf/bpf-next.git (refs/heads/master):

On Wed, 16 Jun 2021 12:25:34 +0800 you wrote:
> Fix to return a negative error code from the error handling
> case instead of 0, as done elsewhere in this function.
> 
> If bpf_map_update_elem() failed, main() should return a negative error.
> 
> Fixes: 832622e6bd18 ("xdp: sample program for new bpf_redirect helper")
> Signed-off-by: Wang Hai <wanghai38@huawei.com>
> 
> [...]

Here is the summary with links:
  - [bpf] samples/bpf: Fix the error return code of xdp_redirect's main()
    https://git.kernel.org/bpf/bpf-next/c/7c6090ee2a7b

You are awesome, thank you!
--
Deet-doot-dot, I am a bot.
https://korg.docs.kernel.org/patchwork/pwbot.html
Jesper Dangaard Brouer July 2, 2021, 10:29 a.m. UTC | #2
On 16/06/2021 06.25, Wang Hai wrote:
> Fix to return a negative error code from the error handling
> case instead of 0, as done elsewhere in this function.

The main() function in C should never return a negative value on Unix 
POSIX systems.


There is a good explaination in exit(3p): `man 3p exit`

    The  value  of  status may be 0, EXIT_SUCCESS, EXIT_FAILURE, or any 
other value, though only the least significant 8 bits (that is, status & 
0377) shall be available to a waiting parent process.

Thus, negative values are often seen as 255 in the $? program exit 
status variable $?.


Also explained in exit(3):

     The C standard specifies two constants, EXIT_SUCCESS=0 and 
EXIT_FAILURE=1.

I see the 'samples/bpf/xdp_redirect_user.c' in most places just use 0 or 1.


> If bpf_map_update_elem() failed, main() should return a negative error.
>
> Fixes: 832622e6bd18 ("xdp: sample program for new bpf_redirect helper")
> Signed-off-by: Wang Hai <wanghai38@huawei.com>
> ---
>   samples/bpf/xdp_redirect_user.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/samples/bpf/xdp_redirect_user.c b/samples/bpf/xdp_redirect_user.c
> index 41d705c3a1f7..c903f1ccc15e 100644
> --- a/samples/bpf/xdp_redirect_user.c
> +++ b/samples/bpf/xdp_redirect_user.c
> @@ -213,5 +213,5 @@ int main(int argc, char **argv)
>   	poll_stats(2, ifindex_out);
>   
>   out:
> -	return 0;
> +	return ret;
>   }


(Sorry, I didn't complain it time as I see this patch is already applied)
wanghai (M) July 5, 2021, 7:45 a.m. UTC | #3
在 2021/7/2 18:29, Jesper Dangaard Brouer 写道:
>
> On 16/06/2021 06.25, Wang Hai wrote:
>> Fix to return a negative error code from the error handling
>> case instead of 0, as done elsewhere in this function.
>
> The main() function in C should never return a negative value on Unix 
> POSIX systems.
>
>
> There is a good explaination in exit(3p): `man 3p exit`
>
>    The  value  of  status may be 0, EXIT_SUCCESS, EXIT_FAILURE, or any 
> other value, though only the least significant 8 bits (that is, status 
> & 0377) shall be available to a waiting parent process.
>
> Thus, negative values are often seen as 255 in the $? program exit 
> status variable $?.
>
>
> Also explained in exit(3):
>
>     The C standard specifies two constants, EXIT_SUCCESS=0 and 
> EXIT_FAILURE=1.
>
> I see the 'samples/bpf/xdp_redirect_user.c' in most places just use 0 
> or 1.
>
Got it, thanks for the explanation, I will fix it to return 1, just like 
the other error paths in samples/bpf/xdp_redirect_user.c
>
>> If bpf_map_update_elem() failed, main() should return a negative error.
>>
>> Fixes: 832622e6bd18 ("xdp: sample program for new bpf_redirect helper")
>> Signed-off-by: Wang Hai <wanghai38@huawei.com>
>> ---
>>   samples/bpf/xdp_redirect_user.c | 2 +-
>>   1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/samples/bpf/xdp_redirect_user.c 
>> b/samples/bpf/xdp_redirect_user.c
>> index 41d705c3a1f7..c903f1ccc15e 100644
>> --- a/samples/bpf/xdp_redirect_user.c
>> +++ b/samples/bpf/xdp_redirect_user.c
>> @@ -213,5 +213,5 @@ int main(int argc, char **argv)
>>       poll_stats(2, ifindex_out);
>>     out:
>> -    return 0;
>> +    return ret;
>>   }
>
>
> (Sorry, I didn't complain it time as I see this patch is already applied)
>
> .
>
diff mbox series

Patch

diff --git a/samples/bpf/xdp_redirect_user.c b/samples/bpf/xdp_redirect_user.c
index 41d705c3a1f7..c903f1ccc15e 100644
--- a/samples/bpf/xdp_redirect_user.c
+++ b/samples/bpf/xdp_redirect_user.c
@@ -213,5 +213,5 @@  int main(int argc, char **argv)
 	poll_stats(2, ifindex_out);
 
 out:
-	return 0;
+	return ret;
 }