Re: [patch V9 00/39] x86/entry: Rework leftovers (was part V)

2020-06-04 Thread Peter Zijlstra
On Thu, Jun 04, 2020 at 08:42:52AM -0700, Andy Lutomirski wrote: > x86 is not an architecture. x86 is a gauntlet through which operating > system developers must run. That made my day :-) > I think we can tolerate this particular mess -- can't we just say that > a BUS LOCK DEBUG EXCEPTION is

Re: [patch V9 00/39] x86/entry: Rework leftovers (was part V)

2020-06-04 Thread Andy Lutomirski
On Thu, Jun 4, 2020 at 6:35 AM Peter Zijlstra wrote: > > On Thu, Jun 04, 2020 at 03:29:26PM +0200, Paolo Bonzini wrote: > > On 04/06/20 15:25, Peter Zijlstra wrote: > > > It being enabled through IA32_DEBUGCTL instead of through DR7 means that > > > the current code doesn't disable it and this

Re: [patch V9 00/39] x86/entry: Rework leftovers (was part V)

2020-06-04 Thread Peter Zijlstra
On Thu, Jun 04, 2020 at 03:29:26PM +0200, Paolo Bonzini wrote: > On 04/06/20 15:25, Peter Zijlstra wrote: > > It being enabled through IA32_DEBUGCTL instead of through DR7 means that > > the current code doesn't disable it and this then means we can have > > nested #DB again. > > /me bangs head

Re: [patch V9 00/39] x86/entry: Rework leftovers (was part V)

2020-06-04 Thread Paolo Bonzini
On 04/06/20 15:25, Peter Zijlstra wrote: > It being enabled through IA32_DEBUGCTL instead of through DR7 means that > the current code doesn't disable it and this then means we can have > nested #DB again. /me bangs head on door > Who sodding throught this was a good idea ?! What happened to #AC

Re: [patch V9 00/39] x86/entry: Rework leftovers (was part V)

2020-06-04 Thread Peter Zijlstra
On Wed, Jun 03, 2020 at 08:18:44PM +0100, Andrew Cooper wrote: > Well that didn't last long... > > The new ISE (rev 39, published today) introduces BUS LOCK DEBUG > EXCEPTION which is now a second inverted polarity sticky bit (bit 11) in > %dr6. > > This one is liable to get more traction than

Re: [patch V9 00/39] x86/entry: Rework leftovers (was part V)

2020-06-03 Thread Andrew Cooper
On 22/05/2020 22:17, Peter Zijlstra wrote: > On Fri, May 22, 2020 at 08:20:15AM +0100, Andrew Cooper wrote: >> Apologies for opening a related can of worms. >> >> The new debug_enter() has propagated a pre-existing issue forward, >> ultimately caused by bad advice in the SDM. >> >> Because the RTM

Re: [patch V9 00/39] x86/entry: Rework leftovers (was part V)

2020-05-25 Thread Andy Lutomirski
On Thu, May 21, 2020 at 1:31 PM Thomas Gleixner wrote: > > Folks! > > This is V9 of the rework series. V7 and V8 were never posted but I used the > version numbers for tags while fixing up 0day complaints. The last posted > version was V6 which can be found here: The whole pile is Acked-by: Andy

Re: [patch V9 00/39] x86/entry: Rework leftovers (was part V)

2020-05-22 Thread Peter Zijlstra
On Fri, May 22, 2020 at 08:20:15AM +0100, Andrew Cooper wrote: > Apologies for opening a related can of worms. > > The new debug_enter() has propagated a pre-existing issue forward, > ultimately caused by bad advice in the SDM. > > Because the RTM status bit in DR6 has inverted polarity, writing

Re: [patch V9 00/39] x86/entry: Rework leftovers (was part V)

2020-05-22 Thread Thomas Gleixner
Thomas Gleixner writes: > Boris Ostrovsky writes: >> On 5/21/20 4:05 PM, Thomas Gleixner wrote: >>> >>> The full series is available from: >>> >>> git://git.kernel.org/pub/scm/linux/kernel/git/tglx/devel.git >>> entry-v9-the-rest >> >> >> Did you mean noinstr-v9-the-rest? I don't see

Re: [patch V9 00/39] x86/entry: Rework leftovers (was part V)

2020-05-22 Thread Thomas Gleixner
Boris Ostrovsky writes: > On 5/21/20 4:05 PM, Thomas Gleixner wrote: >> >> The full series is available from: >> >> git://git.kernel.org/pub/scm/linux/kernel/git/tglx/devel.git >> entry-v9-the-rest > > > Did you mean noinstr-v9-the-rest? I don't see entry-v9-the-rest tag. Bah. Yes. > (Also,

Re: [patch V9 00/39] x86/entry: Rework leftovers (was part V)

2020-05-22 Thread Boris Ostrovsky
On 5/21/20 4:05 PM, Thomas Gleixner wrote: > > The full series is available from: > > git://git.kernel.org/pub/scm/linux/kernel/git/tglx/devel.git > entry-v9-the-rest Did you mean noinstr-v9-the-rest? I don't see entry-v9-the-rest tag. (Also, this series as posted probably won't build. At

Re: [patch V9 00/39] x86/entry: Rework leftovers (was part V)

2020-05-22 Thread Andrew Cooper
On 21/05/2020 21:05, Thomas Gleixner wrote: > Folks! > > This is V9 of the rework series. V7 and V8 were never posted but I used the > version numbers for tags while fixing up 0day complaints. The last posted > version was V6 which can be found here: > >

[patch V9 00/39] x86/entry: Rework leftovers (was part V)

2020-05-21 Thread Thomas Gleixner
Folks! This is V9 of the rework series. V7 and V8 were never posted but I used the version numbers for tags while fixing up 0day complaints. The last posted version was V6 which can be found here: https://lore.kernel.org/r/20200515234547.710474...@linutronix.de The V9 leftover series is based