Re: [RFC/INCOMPLETE 08/13] x86/entry/64: Migrate 64-bit syscalls to new exit hooks

From: Ingo Molnar <mingo@kernel.org>
To: Andy Lutomirski <luto@kernel.org>
Cc: x86@kernel.org, linux-kernel@vger.kernel.org,
	"Frédéric Weisbecker" <fweisbec@gmail.com>,
	"Rik van Riel" <riel@redhat.com>,
	"Oleg Nesterov" <oleg@redhat.com>,
	"Denys Vlasenko" <vda.linux@googlemail.com>,
	"Borislav Petkov" <bp@alien8.de>,
	"Kees Cook" <keescook@chromium.org>,
	"Brian Gerst" <brgerst@gmail.com>,
	"Linus Torvalds" <torvalds@linux-foundation.org>
Subject: Re: [RFC/INCOMPLETE 08/13] x86/entry/64: Migrate 64-bit syscalls to new exit hooks
Date: Wed, 17 Jun 2015 12:02:42 +0200	[thread overview]
Message-ID: <20150617100242.GA6015@gmail.com> (raw)
In-Reply-To: <20150617100009.GA5673@gmail.com>

* Ingo Molnar <mingo@kernel.org> wrote:

> 
> * Andy Lutomirski <luto@kernel.org> wrote:
> 
> > This is separate for ease of bisection.
> > 
> > Signed-off-by: Andy Lutomirski <luto@kernel.org>
> > ---
> >  arch/x86/entry/entry_64.S | 68 +++++------------------------------------------
> >  1 file changed, 7 insertions(+), 61 deletions(-)
> > 
> > diff --git a/arch/x86/entry/entry_64.S b/arch/x86/entry/entry_64.S
> > index 33acc3dcc281..a5044d7a9d43 100644
> > --- a/arch/x86/entry/entry_64.S
> > +++ b/arch/x86/entry/entry_64.S
> > @@ -229,6 +229,11 @@ entry_SYSCALL_64_fastpath:
> >  	 */
> >  	USERGS_SYSRET64
> >  
> > +GLOBAL(int_ret_from_sys_call_irqs_off)
> > +	TRACE_IRQS_ON
> > +	ENABLE_INTERRUPTS(CLBR_NONE)
> > +	jmp int_ret_from_sys_call
> 
> Any reason why irq state tracking cannot be done in C as well, like the rest of 
> the irq state tracking code?

Never mind, I see you've done exactly that in patch #12.

Thanks,

	Ingo