On Tue, Jul 31, 2012 at 03:40:01PM +0200, Ralf Baechle wrote:
> On Sat, Jun 16, 2012 at 12:22:53AM +0200, Lluis Batlle i Rossell wrote:
>
> > Reusing most of the code from lw,ld,sw,sd emulation,
> > I add the emulation for lwc1,ldc1,swc1,sdc1.
> >
> > This avoids the direct SIGBUS sent to userspace processes that have
> > misaligned memory accesses.
> >
> > I've tested the change in Loongson2F, with an own test program, and
> > WebKit 1.4.0, as both were killed by sigbus without this patch.
>
> A misaligned FPU access is a strong indication for broken, non-portable
> software. which means you're likely trying to fix the wrong issue. It's
> quite intentional that there is no unaligned handling for the FPU in the
> kernel - and afaics there isn't for any other MIPS UNIX.
Ah, I had no idea it was intentional.
Maybe there could be a cleaner declaration of that intention, though. The only
code there was "I herewith declare: this does not happen. So send SIGBUS."
Thank you,
Lluís.
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