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Message-ID: <20150611123654.GA24528@amd>
Date: Thu, 11 Jun 2015 14:36:54 +0200
From: Pavel Machek <pavel@....cz>
To: Josh Poimboeuf <jpoimboe@...hat.com>
Cc: Thomas Gleixner <tglx@...utronix.de>,
Ingo Molnar <mingo@...hat.com>,
"H. Peter Anvin" <hpa@...or.com>, Michal Marek <mmarek@...e.cz>,
Peter Zijlstra <peterz@...radead.org>,
Andy Lutomirski <luto@...nel.org>,
Borislav Petkov <bp@...en8.de>,
Linus Torvalds <torvalds@...ux-foundation.org>,
Andi Kleen <andi@...stfloor.org>, x86@...nel.org,
live-patching@...r.kernel.org, linux-kernel@...r.kernel.org,
"Rafael J. Wysocki" <rjw@...ysocki.net>,
Len Brown <len.brown@...el.com>, linux-pm@...r.kernel.org
Subject: Re: [PATCH v5 07/10] x86/asm/acpi: Fix asmvalidate warnings for
wakeup_64.S
Hi!
> > > 5. Remove superfluous rsp changes.
> >
> > Did you test the changes?
>
> Yes, I verified that it didn't break suspend/resume on my system.
Ok, so I can not see anything wrong, either. I'd like to understand
why the original code manipulated %rsp, but...
If you did testing with frame pointer on, you can get my
Acked-by: Pavel Machek <pavel@....cz>
> > Do you plan to make similar changes to wakeup_32.S?
>
> Currently, asmvalidate is x86_64 only, so I'm only fixing the 64-bit
> stuff right now.
Well, you are "improving debuggability", afaict. It worked well before.
> > > @@ -108,8 +108,9 @@ ENTRY(do_suspend_lowlevel)
> > > movq pt_regs_r15(%rax), %r15
> > >
> > > xorl %eax, %eax
> > > - addq $8, %rsp
> > > - jmp restore_processor_state
> > > + call restore_processor_state
> > > + FP_RESTORE
> > > + ret
> > > ENDPROC(do_suspend_lowlevel)
> >
> > Umm. I rather liked the direct jump.
>
> Why?
It is both smaller and faster than the new code. But...
Pavel
--
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