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Date: Tue, 14 Oct 2003 16:15:00 -0000
From: Andrew Cagney <ac131313@redhat.com>
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To: Daniel Jacobowitz <drow@mvista.com>
Cc: Joel Brobecker <brobecker@gnat.com>,
	Andrew Cagney <ac131313@redhat.com>, gdb-patches@sources.redhat.com
Subject: Re: problem unwinding past pthread_cond_wait() on x86 RedHat 9.0
References: <20031014054225.GB919@gnat.com> <20031014125731.GA14097@nevyn.them.org> <3F8C1523.5040704@redhat.com> <20031014154649.GA989@gnat.com> <20031014155211.GB10669@nevyn.them.org>
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> On Tue, Oct 14, 2003 at 08:46:49AM -0700, Joel Brobecker wrote:
> 
>> > Joel, what happens if you type:
>> > 
>> > (gdb) x/i 0xffffe002
> 
>> 
>> Something like "Cannot read memory at 0xffffe002" (already tried it :-).
>> What is this address, BTW. I always wondered... Kernel code? Special
>> address?
> 
> 
> Search for "vsyscall DSO" in the gdb@ archives to learn more than you
> ever wanted to know :)  Patches to fully support it are still pending.

No.

No matter how much you patch GDB, GDB isn't going to dig itself out of 
thishole.  It's not able to access the code/data/whatever at that 
address so it's never going to correctly unwind from it.

Kernel bug - incomplete functionality.

Andrew