Re: [PATCH 1/2] x86: save r11 into pt_regs->flags on SYSCALL64 fastpath

[Ingo Molnar]

* Denys Vlasenko <dvlasenk@xxxxxxxxxx> wrote:

> Before this patch, r11 was saved in pt_regs->r11.
> Which looks natural, but requires messy shuffling to/from iret frame
> whenever ptrace or e.g. iopl wants to modify flags - because
> that's how this register is used by SYSCALL/SYSRET.
> 
> This patch saves r11 in pt_regs->flags,
> and uses that value for SYSRET64 insn. Shuffling is eliminated.
> 
> stub_iopl is no longer needed: pt_regs->flags needs no fixing up.

Could you please split this into two patches: R11 saving, and 
stub_iopl removal?

For x86/asm changes we want as small changes as physically possible.

Thanks,

	Ingo
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