PowerPC kernel bug. (fwd)

[James Simmons]

Geert I know you work with the PowerPC people. I don't belong to the list
so it might not go threw. So could you post it as well.

Subject: PowerPC kernel bug.
Date:    Mon, 13 Dec 1999 22:03:26 -0500 (EST)
From:    James Simmons <jsimmons at edgeglobal.com>
To:      GLX mailing list <glx-dev at lists.openprojects.net>, FrameBuffer List
<linux-fbdev at vuser.vu.union.edu>, Linux Kernel Mailing List
<linux-kernel at vger.rutgers.edu>


This message is toward the Fbdev/kernel group to fix this bug but I wanted
to let the GLX group what caused the memset problem on PowerPC. On a
PowerPC when you mmap the framebuffer and use memset on the mmapped
image you get a SIGBUS. Thanks Marcus for finding out what was causing the
problem.

>I noticed today that it's actually a bug in the PPC-kernel. The
>specification for the dcbz (data cache block zero) instruction
>states that for uncached memory the exception handler should clear
>the memory, but on Linux it just causes a SIGBUS to be sent to the
>app...
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