Re: [PATCH bpf-next v2 0/5] Subskeleton support for BPF libraries

[Delyan Kratunov <delyank@fb.com>]

On Thu, 2022-03-10 at 21:10 -0800, Yonghong Song wrote:
> 
> On 3/10/22 4:11 PM, Delyan Kratunov wrote:
[..]
> 
> When I tried to build the patch set with parallel mode (-j),
>     make -C tools/testing/selftests/bpf -j
> I hit the following errors:
> 
> /bin/sh: line 1: 3484984 Bus error               (core dumped) 
> /home/yhs/work/bpf-next/tools/testing/selftests/bpf/tools/sbin/bpftool 
> gen skeleton 
> /home/yhs/work/bpf-next/tools/testing/selftests/bpf/test_ksyms_weak.linked3.o 
> name test_ksyms_weak > 
> /home/yhs/work/bpf-next/tools/testing/selftests/bpf/test_ksyms_weak.skel.h
> make: *** [Makefile:496: 
> /home/yhs/work/bpf-next/tools/testing/selftests/bpf/test_ksyms_weak.skel.h] 
> Error 135
> make: *** Deleting file 
> '/home/yhs/work/bpf-next/tools/testing/selftests/bpf/test_ksyms_weak.skel.h'
> make: *** Waiting for unfinished jobs....
> make: Leaving directory 
> '/home/yhs/work/bpf-next/tools/testing/selftests/bpf'
> 
> Probably some make file related issues.
> I didn't hit this issue before without this patch set.

Hm, that's interesting, can you reproduce it? I build everything with -j and
have not seen any bpftool issues. I also use ASAN for bpftool and that's not
complaining about anything either.

SIGBUS suggests a memory mapped file was not there. I'll try and come up with
ways that can happen, especially given that it's a `gen skeleton` invocation,
which I haven't changed at all.

--Delyan