Re: kgdb on CURRENT?

From: Dimitry Andric <dim_at_FreeBSD.org>
Date: Thu, 6 Mar 2014 17:53:22 +0100
On 06 Mar 2014, at 17:33, Lev Serebryakov <lev_at_freebsd.org> wrote:
> CURRENT r262833, kernel from custom config (with symbols ad debugging
> info), crash.
> 
> savecore says "Unable to find matching kernel"
> 
> kgdb /var/crash/vmcore.1 /boot/kerne/kernel says:
> 
> Dwarf Error: wrong version in compilation unit header (is 4, should be 2) [in module /boot/kernel/kernel.symbols]
> 
> Is it local problem or kgdb is broken with latest clang import?

No, clang 3.4 just defaults to DWARF4 format, which kgdb does not grok.
Please put the following in your custom kernel configuration, similar to
GENERIC:

makeoptions     DEBUG=-gdwarf-2         # Build kernel with gdb(1) debug symbols

Now on a side note, it would be very nice if our kernel debugging
extensions were ported to the ports version of gdb, which is
non-ancient... :-)

-Dimitry


Received on Thu Mar 06 2014 - 15:53:41 UTC

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