From: Andi Kleen <ak@muc.de>
To: Rusty Russell <rusty@rustcorp.com.au>
Cc: Chuck Ebbert <76306.1226@compuserve.com>,
linux-kernel <linux-kernel@vger.kernel.org>,
Andrew Morton <akpm@osdl.org>
Subject: Re: [PATCH 5/6] Begin abstraction of sensitive instructions: asm files
Date: 24 Jul 2006 19:36:29 +0200
Date: Mon, 24 Jul 2006 19:36:29 +0200 [thread overview]
Message-ID: <20060724173629.GB50320@muc.de> (raw)
In-Reply-To: <1153575288.13198.16.camel@localhost.localdomain>
On Sat, Jul 22, 2006 at 11:34:48PM +1000, Rusty Russell wrote:
> On Fri, 2006-07-21 at 23:23 -0400, Chuck Ebbert wrote:
> > In-Reply-To:<1153527274.13699.36.camel@localhost.localdomain>
> >
> > On Sat, 22 Jul 2006 10:14:34 +1000, Rusty Russell wrote:
> > > +#define GET_CR0 movl %cr0, %eax
> >
> > Could you change GET_CR0 to MOV_CR0_EAX? GET_CR0 seems like it's
> > taking a reference or something.
>
> Hi Chuck,
>
> Agreed: certainly eax should be mentioned. GET_CR0_INTO_EAX? MOV is a
> bit close to describing how it's happening (which, on paravirt it might
> not be) so it might lead the reader to unwarranted assumptions.
>
> ===
> Abstract sensitive instructions in assembler code, replacing them with
> macros (which currently are #defined to the native versions). We use
> long names: assembler is case-insensitive, so if something goes wrong
> and macros do not expand, it would assemble anyway.
>
> Resulting object files are exactly the same as before.
>
> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
> Index: working-2.6.18-rc2-hg-paravirt/arch/i386/kernel/entry.S
> ===================================================================
> --- working-2.6.18-rc2-hg-paravirt.orig/arch/i386/kernel/entry.S 2006-07-21 21:09:22.000000000 +1000
> +++ working-2.6.18-rc2-hg-paravirt/arch/i386/kernel/entry.S 2006-07-22 04:32:25.000000000 +1000
> @@ -76,8 +76,15 @@
> NT_MASK = 0x00004000
> VM_MASK = 0x00020000
>
> +/* These are replaces for paravirtualization */
> +#define DISABLE_INTERRUPTS cli
> +#define ENABLE_INTERRUPTS sti
> +#define ENABLE_INTERRUPTS_SYSEXIT sti; sysexit
> +#define INTERRUPT_RETURN iret
> +#define GET_CR0_INTO_EAX movl %cr0, %eax
I would rather pass the register to the macro? If you start to
clobber registers you would need to pass in the tmp registers
too I guess.
-Andi
next prev parent reply other threads:[~2006-07-24 17:36 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-07-22 3:23 [PATCH 5/6] Begin abstraction of sensitive instructions: asm files Chuck Ebbert
2006-07-22 13:34 ` Rusty Russell
2006-07-24 17:36 ` Andi Kleen [this message]
2006-07-24 20:54 ` Jeremy Fitzhardinge
2006-07-25 23:52 ` Peter Chubb
2006-07-26 3:25 ` Rusty Russell
-- strict thread matches above, loose matches on Subject: below --
2006-07-22 0:14 Rusty Russell
2006-07-30 10:52 ` Pavel Machek
2006-07-30 10:56 ` Pavel Machek
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