Re: kernel compile fails if device bpf is not enabled

> On Feb 8, 2023, at 2:32 PM, Gary Jennejohn <garyj@gmx.de> wrote:
> 
> On Wed, 8 Feb 2023 12:49:46 +0800
> Zhenlei Huang <zlei@FreeBSD.org <mailto:zlei@FreeBSD.org>> wrote:
> 
> Hi Zhenlei,
> 
>> Thanks for the report! Post the fix to Phabricator https://reviews.freebsd.org/D38432 <https://reviews.freebsd.org/D38432> <https://reviews.freebsd.org/D38432 <https://reviews.freebsd.org/D38432>> .
>> 
>> Best regards,
>> Zhenlei
>> 
> 
> Thanks!  I see it's been accepted.

Fixed in 9df6eeabb379 .

> 
>>> On Feb 7, 2023, at 5:08 PM, Gary Jennejohn <garyj@gmx.de> wrote:
>>> 
>>> I just saw this error today because I didn't have device bpf enabled in
>>> my kernel configuration file:
>>> 
>>> --------------------------------------------------------------
>>>>>> stage 3.1: building everything
>>> --------------------------------------------------------------
>>> linking kernel.full
>>> ld: error: undefined symbol: bpf_mtap_if
>>>>>> referenced by if.c:4724 (/usr/src/sys/net/if.c:4724)
>>>>>>             if.o:(if_bpfmtap)
>>>>>> referenced by if_tuntap.c:1717 (/usr/src/sys/net/if_tuntap.c:1717)
>>>>>>             if_tuntap.o:(tunread)
>>>>>> referenced by if_vlan.c:1292 (/usr/src/sys/net/if_vlan.c:1292)
>>>>>>             if_vlan.o:(vlan_transmit)
>>> 
>>> ld: error: undefined symbol: bpf_mtap2_if
>>>>>> referenced by if_gif.c:323 (/usr/src/sys/net/if_gif.c:323)
>>>>>>             if_gif.o:(gif_transmit)
>>>>>> referenced by if_tuntap.c:1816 (/usr/src/sys/net/if_tuntap.c:1816)
>>>>>>             if_tuntap.o:(tunwrite)
>>> --- kernel.full ---
>>> *** [kernel.full] Error code 1
>>> 
>>> This happens because a dummy bpf_mtap_if() (called a NOP stub in bpf.c)
>>> isn't being defined if bpf is not enabled.
>>> 
>>> --
>>> Gary Jennejohn
>>> 
> 
> --
> Gary Jennejohn