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Date: Sun, 5 May 2013 14:00:06 +0100
From: Andrew Turner <andrew@fubar.geek.nz>
To: Tim Kientzle <tim@kientzle.com>
Subject: Re: Is this related to the general panic discussed in freebsd-current?
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On Sat, 4 May 2013 15:44:37 -0700
Tim Kientzle <tim@kientzle.com> wrote:
> I'm baffled.  If I insert a printf into the loop in stack_capture,
> the kernel boots. But the generated assembly looks perfectly correct
> to me in either case.  So inserting the printf must have some
> side-effect.
> 
> The stack does end up aligned differently:  The failing version puts
> 16 bytes on the stack, the working version puts 24 bytes.  But I
> can't figure out how that would explain what I'm seeing...

It feels like an alignment issue but those stack sizes should both be
valid. Are you able to send me the asm for the working and broken
versions of the function?

Also which ABI are you using? I have not been able to reproduce it with
EABI, but that may have been because I have a patched clang I've been
using to track down another issue.

Andrew