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Valeriy E. Ushakov | 1 Jun 2008 03:57
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Re: sh3 mcontext change

On Mon, May 26, 2008 at 23:19:07 +0400, Valeriy E. Ushakov wrote:

> On Mon, May 26, 2008 at 18:35:24 +0000, Christos Zoulas wrote:
> 
> > In article <20080526174637.GE15029 <at> bigmac.stderr.spb.ru>,
> > Valeriy E. Ushakov <uwe <at> NetBSD.org> wrote:
> > > With NetBSD 5.0 looming, I'd like to fix a problem with sh3 mcontext
> > > that's been there since the very beginning - it doesn't have a slot
> > > for GBR register.
> > >
> > > Currently kernel doesn't preserve GBR and userland doesn't use it
> > > either - unless you write you own asm code, in which case you lose -
> > > which is bad by itself already.  And GBR is also used by TLS, though
> > > our ld.so doesn't support it yet.
> > >
> > > The problem of course is how to change mcontext without breaking ABI
> > > (sizeof(struct mcontext)).  Fortunately, it seems we have a slot we
> > > can steal - we have _REG_EXPEVT slot in gregs and it seems it's
> > > unused.  cpu_setmcontext() in the kernel doesn't set it for obvious
> > > reasons and as far as I can tell no code ever examines it - all kernel
> > > code that is interested in expevt uses trapframe for that.  Userland
> > > code that might be interested in expevt (reason for the trap) already
> > > gets the same info via siginfo.
> > >
> > > So i would like to recycle that currently useless slot for GBR and
> > > thus avoid breaking ABI.
> > >
> > > Just in case - is there anything I'm missing here?  Any
> > > objections/comments?
> >
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David Laight | 4 Jun 2008 23:09
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Re: sh3 mcontext change

On Sun, Jun 01, 2008 at 05:57:30AM +0400, Valeriy E. Ushakov wrote:
> 
> Anything *else* I'm missing?

gdb ?
It probably has it's own private definition of (one of) the register layouts,
with nothing at all anywhere to help you cross link the definitions.

	David

--

-- 
David Laight: david <at> l8s.co.uk
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Paula Grassi | 12 Jun 2008 06:09

Uma frase e uma sugestao


 ,

Saudaçoes. Tenho certeza que conhece a frase que diz: "Propaganda e a alma do 
negocio". Por isso estou escrevendo para te lembrar da grande utilidade do email 
marketing para a divulgaçao do seu negocio.

Os   estao a sua disposiçao, mas estao tambem a disposiçao dos seus concorrentes. 
Por isso conquiste primeiro este mercado antes que seja conquistado por outras 
pessoas. Que tal iniciar a sua campanha esta semana?

Cordialmente,
Paula Grassi
http://www.divulgaemails.com
(0xx71)3491-9005 ou (0xx71)9932-0158(24h)
MSN e SKYPE: dvgmail
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