RE: [tip:x86/urgent] x86/entry: Restore traditional SYSENTER calling convention

[Zhuo, Qiuxu]

Hi Linus and Andy,

  We did test in our side with v4.4-rc8 + Andy's vDSO v2 patches + Android M (bionic libc using sysenter) ==> Device can boot up successfully

  Other tests were:
  - Android L (bionic libc using int80) + v4.4-rc8 ==> Device can boot up successfully
  - Android L (bionic libc using int80) + v4.4-rc8 + Andy's v2 patches ==> Device can boot up successfully
  - Android M (bionic libc using sysenter) + v4.4-rc8 ==> Device can NOT boot up successfully
  - Android M (bionic libc using sysenter) + v4.4-rc8 + Andy's v2 patches ==> Device can boot up successfully

   Thanks!
BR
qiuxu

-----Original Message-----
From: linus971@xxxxxxxxx [mailto:linus971@xxxxxxxxx] On Behalf Of Linus Torvalds
Sent: Tuesday, January 5, 2016 3:28 AM
To: H. Peter Anvin
Cc: Andy Lutomirski; Shi, Mingwei; Fu, Borun; Gross, Mark; Andrew Lutomirski; Su, Tao; Borislav Petkov; Ingo Molnar; Brian Gerst; linux-kernel@xxxxxxxxxxxxxxx; Zhuo, Qiuxu; Thomas Gleixner; Denys Vlasenko; Wang, Frank; linux-tip-commits@xxxxxxxxxxxxxxx
Subject: Re: [tip:x86/urgent] x86/entry: Restore traditional SYSENTER calling convention

On Mon, Jan 4, 2016 at 10:48 AM, H. Peter Anvin <hpa@xxxxxxxxx> wrote:
>
> Linus has frequently stated that if it is something that is critical 
> enough for stable, it is critical enough for final.  Linus will decide 
> if an additional -rc is needed for that reason.

So it would have been good to have it in an -rc, but at the same time I'm not particularly worried about this one.

It's not like it's complicated, and I'm assuming it got tested and passed all our current test-cases (which are much more complete than anything we've ever had historically).

                     Linus