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<p>Hello Alarig,</p>
<p>this was indeed a problem (and there was some more to fix) and if I
haven’t missed anything (but it now looks OK for me), here is a fixed
version: <a
href="https://gitlab.nic.cz/labs/bird/-/commit/2e14832d36c83b2ab5b7fb28b701de554fa5fdd9"
class="uri">https://gitlab.nic.cz/labs/bird/-/commit/2e14832d36c83b2ab5b7fb28b701de554fa5fdd9</a></p>
<p>If you could check that it works for you as well, it would be very
helpful.</p>
<p>Thank you for your report!<br />
Maria</p>
<p>On Tue, Dec 31, 2024 at 10:05:12AM +0100, Alarig Le Lay via
Bird-users wrote:</p>
<blockquote>
<p>I read the coredump (and the source code) with a fresh cup of coffee,
and acted accordingly:</p>
<p>The error is there: Program terminated with signal SIGSEGV,
Segmentation fault. #0 0x000055861e8cb989 in bgp_rte_recalculate
(table=0x55861fe0a250, net=0x55861fe1b320, new_stored=0x7f13aaedd070,
old_stored=0x0, old_best_stored=0x0) at proto/bgp/attrs.c:2696</p>
<p>Which corresponds to the deterministic med:
https://gitlab.nic.cz/labs/bird/-/blob/v3.0.0/proto/bgp/attrs.c?ref_type=tags#L2696
int old_suppressed = old ? !!(old->pflags & BGP_REF_SUPPRESSED) :
0;</p>
<p>To be used there:
https://gitlab.nic.cz/labs/bird/-/blob/v3.0.0/proto/bgp/attrs.c?ref_type=tags#L2455
n = new->pflags & BGP_REF_SUPPRESSED; o = old->pflags &
BGP_REF_SUPPRESSED;</p>
<p>So I commented it and now bird starts: rr3 ~ # grep med
/etc/bird.conf med metric on; #deterministic med on; med metric on;
#deterministic med on;</p>
<p>On Mon 30 Dec 2024 22:35:02 GMT, Alarig Le Lay wrote:</p>
<blockquote>
<p>Hello David,</p>
<p>Here is the coredump:
https://herbizarre.swordarmor.fr/garbage/core-bird.29074.rr3.swordarmor.fr.1735592879
And here is the config:
https://herbizarre.swordarmor.fr/garbage/bird.conf.29074.rr3.swordarmor.fr.1735592879</p>
<p>I compiled bird3 with the two previous patches of this ML:</p>
<ul>
<li>Applying bird-3.0.0-nest-rt-table.c.patch …</li>
<li>Applying bird-3.0.0-proto-lock.patch …</li>
</ul>
<p>And I enabled the debug:</p>
<p>./configure –prefix=/usr –build=x86_64-pc-linux-gnu
–host=x86_64-pc-linux-gnu –mandir=/usr/share/man
–infodir=/usr/share/info –datadir=/usr/share –sysconfdir=/etc
–localstatedir=/var/lib –datarootdir=/usr/share
–docdir=/usr/share/doc/bird-3.0.0
–htmldir=/usr/share/doc/bird-3.0.0/html –libdir=/usr/lib64
–localstatedir=/var –enable-client –enable-debug –disable-libssh</p>
<p>So I have a different trace in dmesg (I supposed that it’s due to
having debug symbols): [1305799.952226] bird[29075]: segfault at 8 ip
000055861e8cb989 sp 00007f13ab6e0b40 error 4 in
bird[55861e7ed000+15c000] [1305799.952251] Code: 89 c7 e8 13 80 ff ff 89
85 6c ff ff ff 48 8b 45 c0 48 89 c7 e8 2d f3 ff ff 89 85 70 ff ff ff 48
83 7d b0 00 74 18 48 8b 45 b0 <0f> b6 00 0f b6 c0 83 e0 01 85 c0
74 07 b8 01 00 00 00 eb 05 b8 00</p>
<p>Regarding the setup, I don’t think that it’s that unconventional, but
it’s a RR outside of the network (it’s on my own network which is pretty
much experimental, so I experiment). I noticed that I never removed the
OSPF from the kernel filters until now, but even with ‘export none’ I
still get the crash.</p>
<p>So I then tried to enable all the debug options: rr3 ~ # grep debug
/etc/bird.conf debug protocols all; debug channels all; debug tables
all;</p>
<p>And here are the logs: https://paste.swordarmor.fr/raw/Owej</p>
<p>I hope it’s useful, don’t hesitate to ask me if you need anything
else.</p>
<p>Happy new year to you too! Alarig</p>
<p>On Mon 30 Dec 2024 16:49:41 GMT, David Petera wrote:</p>
<blockquote>
<p>Hello Alarig,</p>
<p>thanks for reporting!</p>
<p>The coredump and config would be much appreciated, so I can try
to<br />
reproduce it. Also would you say there is something unconventional about
the said<br />
setup that might be causing the problem?</p>
<p>Thanks in advance and happy new year,</p>
<p>David</p>
<p>On 12/19/24 19:16, Alarig Le Lay via Bird-users wrote:</p>
<blockquote>
<p>Hello Maria,</p>
<p>I thought that I had the same bug, but it seems that it’s a different
one as I applied the patch but I still got a segfault at startup.</p>
<p>[342115.227497] bird[19396]: segfault at 8 ip 00005642c37062db sp
00007fc784295ca0 error 4 in bird[5642c366e000+f0000] [342115.227524]
Code: 39 10 0f 85 e3 8c f6 ff 48 8b 90 b0 01 00 00 8b 8a 10 01 00 00 89
4c 24 24 85 c9 0f 84 d6 00 00 00 4d 85 ff 0f 84 e0 00 00 00 <41>
0f b6 44 24 08 89 c2 83 e2 01 4d 85 ed 75 15 83 c8 01 41 88 44</p>
<p>I can generate a coredump and share my configuration if needed.</p>
<p>Alarig</p>
<p>[…]</p>
</blockquote>
</blockquote>
</blockquote>
</blockquote>
<p>–<br />
Maria Matejka (she/her) | BIRD Team Leader | CZ.NIC, z.s.p.o.</p>
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