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Date: Tue, 4 Sep 2007 12:34:49 +0300
From: "Ivo Vachkov" <ivo.vachkov@gmail.com>
To: freebsd-net <freebsd-net@freebsd.org>
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Subject: Network stack locking question
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X-List-Received-Date: Tue, 04 Sep 2007 09:34:52 -0000

Hello all,

I'm currently working on some ipv6 related code. At some point I have
to do a routing lookup and I meet following problem:

panic: mtx_lock() of spin mutex 'some_strange_chars' ../../../net/route.c:114
cpuid = 0
KDB: enter: panic
[thread pid 17 tid 100021 ]
Stopped at      kdb_enter+0x31: leave

According to the debugger the events happen in the following order:

ether_demux() at ether_demux+
my_func() at my_func+
rtalloc_ign() at rtalloc_ign+
_mtx_lock_flags() at _mtx_lock_flags+
panic() at panic+

I do not include GIANT_REQUIRED in my code. Can you propose a solution
or a pointer to information where I can make myself familiar with the
networking code locking ... besides 'man 9 locking' and related.

Thank you very much in advance.

    Ivo