hello,

i got a warning during kernel compilation.

net/core/skbuff.o: warning: objtool: skb_push.cold()+0x15: unreachable instruction

related clips...

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(gdb) l skb_push.cold 1880 void *skb_push(struct sk_buff *skb, unsigned int len) 1881 { 1882 skb->data -= len; 1883 skb->len += len; 1884 if (unlikely(skb->data < skb->head)) 1885 skb_under_panic(skb, len, __builtin_return_address(0)); 1886 return skb->data; 1887 } 1888 EXPORT_SYMBOL(skb_push); 1889 (gdb) l *0xffffffff815ffc8e 0xffffffff815ffc8e is in skb_push (net/core/skbuff.c:1885). 1880 void *skb_push(struct sk_buff *skb, unsigned int len) 1881 { 1882 skb->data -= len; 1883 skb->len += len; 1884 if (unlikely(skb->data < skb->head)) 1885 skb_under_panic(skb, len, __builtin_return_address(0)); 1886 return skb->data; 1887 } 1888 EXPORT_SYMBOL(skb_push); 1889 (gdb)

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$uname -a Linux debian 5.4.0-rc1+ #1 SMP Sat Nov 9 21:29:48 IST 2019 x86_64 GNU/Linux $

this kernel is from linux-kselftest tree

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$gcc --version gcc (Debian 9.2.1-14) 9.2.1 20191025 Copyright (C) 2019 Free Software Foundation, Inc. This is free software; see the source for copying conditions. There is NO warranty; not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.

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Linux debian 5.4.0-rc1+ #1 SMP Sat Nov 9 21:29:48 IST 2019 x86_64 GNU/Linux

GNU Make 4.2.1 Binutils 2.33.1 Util-linux 2.33.1 Mount 2.33.1 Linux C Library 2.29 Dynamic linker (ldd) 2.29 Procps 3.3.15 Kbd 2.0.4 Console-tools 2.0.4 Sh-utils 8.30 Udev 241

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-- software engineer rajagiri school of engineering and technology