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Subject: Re: [PATCH] net: skbuff: fix missing a __noreturn annotation warning
To:     Paolo Abeni <pabeni@redhat.com>,
        Kuniyuki Iwashima <kuniyu@amazon.com>
CC:     <davem@davemloft.net>, <edumazet@google.com>, <kuba@kernel.org>,
        <linux-kernel@vger.kernel.org>, <netdev@vger.kernel.org>
References: <20230527110409.497408-1-linmiaohe@huawei.com>
 <20230527040038.6783-1-kuniyu@amazon.com>
 <0ab4f3ea2bd97c7067ed332c0128829f4a7ea596.camel@redhat.com>
From:   Miaohe Lin <linmiaohe@huawei.com>
Message-ID: <89ec1a82-7f1d-21f9-4ece-e321b261e9a5@huawei.com>
Date:   Sat, 3 Jun 2023 11:09:23 +0800
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On 2023/5/30 18:28, Paolo Abeni wrote:
> On Fri, 2023-05-26 at 21:00 -0700, Kuniyuki Iwashima wrote:
>> From: Miaohe Lin <linmiaohe@huawei.com>
>> Date: Sat, 27 May 2023 19:04:09 +0800
>>> Add __noreturn annotation to fix the warning:
>>>  net/core/skbuff.o: warning: objtool: skb_push+0x3c: skb_panic() is missing a __noreturn annotation
>>>  net/core/skbuff.o: warning: objtool: skb_put+0x4e: skb_panic() is missing a __noreturn annotation
>>
>> What arch are you using ?
>>
>> IIUC, BUG() should have an annotation for objtool, for
>> example, __builtin_unreachable() for x86.
>>
>> Maybe the arch is missing such an annotation ?
>>
>> Also I'm curious why objtool complains about only skb_push(),
>> there should be more non-inline functions that has BUG().
> 
> AFAICS, the BUG() macro implementation should already carry the
> __noreturn annotation, via panic() or other arch-specific way.
> 
> This looks like the old toolchain not being able to
> successfully/correctly propagate the annotation???

I tend to agree with you. Will drop it. Thanks for your comment.

> 
> I think we can drop this patch.
> 
> Cheers,
> 
> Paolo
> 
> .
>