Re: [GIT PULL] x86: unify sys_iopl

From: Jeremy Fitzhardinge
Date: Fri Sep 25 2009 - 20:22:47 EST


On 09/25/09 16:54, Brian Gerst wrote:
> Using task_pt_regs is less effecient than getting the pointer directly
> from the syscall entry code.

(really not an issue in this case)

> On 32-bit it probably doesn't matter too
> much, but on 64-bit, you still need the special stub code in
> entry_64.S to put the full pt_regs struct on the stack. Changing the
> calling conventions should be a seperate patch, and should be done for
> all pt_regs-using syscalls.
>

iopl only really cares about [er]flags, so it probably doesn't need a
full ptregs structure anyway. But I'm not sure what changes you'd
consider for the rest of the ptregs calls; sigaltstack probably doesn't
need full ptregs either (it just updates [er]sp I think), but fork/clone
definitely do.

J
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