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From: Sean Christopherson <sean.j.christopherson@intel.com>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Lutomirski <luto@kernel.org>,
	Steven Rostedt <rostedt@goodmis.org>,
	Peter Zijlstra <peterz@infradead.org>,
	Nicolai Stange <nstange@suse.de>,
	Thomas Gleixner <tglx@linutronix.de>,
	Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
	"H. Peter Anvin" <hpa@zytor.com>,
	the arch/x86 maintainers <x86@kernel.org>,
	Josh Poimboeuf <jpoimboe@redhat.com>,
	Jiri Kosina <jikos@kernel.org>, Miroslav Benes <mbenes@suse.cz>,
	Petr Mladek <pmladek@suse.com>,
	Joe Lawrence <joe.lawrence@redhat.com>,
	Shuah Khan <shuah@kernel.org>,
	Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>,
	Tim Chen <tim.c.chen@linux.intel.com>,
	Sebastian Andrzej Siewior <bigeasy@linutronix.de>,
	Mimi Zohar <zohar@linux.ibm.com>, Juergen Gross <jgross@suse.com>,
	Nick Desaulniers <ndesaulniers@google.com>,
	Nayna Jain <nayna@linux.ibm.com>,
	Masahiro Yamada <yamada.masahiro@socionext.com>,
	Joerg Roedel <jroedel@suse.de>,
	Linux List Kernel Mailing <linux-kernel@vger.kernel.org>,
	live-patching@vger.kernel.org,
	"open list:KERNEL SELFTEST FRAMEWORK" 
	<linux-kselftest@vger.kernel.org>
Subject: Re: [PATCH 3/4] x86/ftrace: make ftrace_int3_handler() not to skip fops invocation
Date: Mon, 29 Apr 2019 17:45:04 -0700	[thread overview]
Message-ID: <20190430004504.GH31379@linux.intel.com> (raw)
In-Reply-To: <20190430000846.GG31379@linux.intel.com>

On Mon, Apr 29, 2019 at 05:08:46PM -0700, Sean Christopherson wrote:
> On Mon, Apr 29, 2019 at 03:22:09PM -0700, Linus Torvalds wrote:
> > On Mon, Apr 29, 2019 at 3:08 PM Sean Christopherson
> > <sean.j.christopherson@intel.com> wrote:
> > >
> > > FWIW, Lakemont (Quark) doesn't block NMI/SMI in the STI shadow, but I'm
> > > not sure that counters the "horrible errata" statement ;-).  SMI+RSM saves
> > > and restores STI blocking in that case, but AFAICT NMI has no such
> > > protection and will effectively break the shadow on its IRET.
> > 
> > Ugh. I can't say I care deeply about Quark (ie never seemed to go
> > anywhere), but it's odd. I thought it was based on a Pentium core (or
> > i486+?). Are you saying those didn't do it either?
> 
> It's 486 based, but either way I suspect the answer is "yes".  IIRC,
> Knights Corner, a.k.a. Larrabee, also had funkiness around SMM and that
> was based on P54C, though I'm struggling to recall exactly what the
> Larrabee weirdness was.

Aha!  Found an ancient comment that explicitly states P5 does not block
NMI/SMI in the STI shadow, while P6 does block NMI/SMI.

WARNING: multiple messages have this Message-ID (diff)
From: sean.j.christopherson at intel.com (Sean Christopherson)
Subject: [PATCH 3/4] x86/ftrace: make ftrace_int3_handler() not to skip fops invocation
Date: Mon, 29 Apr 2019 17:45:04 -0700	[thread overview]
Message-ID: <20190430004504.GH31379@linux.intel.com> (raw)
In-Reply-To: <20190430000846.GG31379@linux.intel.com>

On Mon, Apr 29, 2019 at 05:08:46PM -0700, Sean Christopherson wrote:
> On Mon, Apr 29, 2019 at 03:22:09PM -0700, Linus Torvalds wrote:
> > On Mon, Apr 29, 2019 at 3:08 PM Sean Christopherson
> > <sean.j.christopherson at intel.com> wrote:
> > >
> > > FWIW, Lakemont (Quark) doesn't block NMI/SMI in the STI shadow, but I'm
> > > not sure that counters the "horrible errata" statement ;-).  SMI+RSM saves
> > > and restores STI blocking in that case, but AFAICT NMI has no such
> > > protection and will effectively break the shadow on its IRET.
> > 
> > Ugh. I can't say I care deeply about Quark (ie never seemed to go
> > anywhere), but it's odd. I thought it was based on a Pentium core (or
> > i486+?). Are you saying those didn't do it either?
> 
> It's 486 based, but either way I suspect the answer is "yes".  IIRC,
> Knights Corner, a.k.a. Larrabee, also had funkiness around SMM and that
> was based on P54C, though I'm struggling to recall exactly what the
> Larrabee weirdness was.

Aha!  Found an ancient comment that explicitly states P5 does not block
NMI/SMI in the STI shadow, while P6 does block NMI/SMI.

WARNING: multiple messages have this Message-ID (diff)
From: sean.j.christopherson@intel.com (Sean Christopherson)
Subject: [PATCH 3/4] x86/ftrace: make ftrace_int3_handler() not to skip fops invocation
Date: Mon, 29 Apr 2019 17:45:04 -0700	[thread overview]
Message-ID: <20190430004504.GH31379@linux.intel.com> (raw)
Message-ID: <20190430004504.wQP1sLN29PFeGIXpuGtG1bpcbDxher1RvSV5dCsXZkk@z> (raw)
In-Reply-To: <20190430000846.GG31379@linux.intel.com>

On Mon, Apr 29, 2019@05:08:46PM -0700, Sean Christopherson wrote:
> On Mon, Apr 29, 2019@03:22:09PM -0700, Linus Torvalds wrote:
> > On Mon, Apr 29, 2019 at 3:08 PM Sean Christopherson
> > <sean.j.christopherson@intel.com> wrote:
> > >
> > > FWIW, Lakemont (Quark) doesn't block NMI/SMI in the STI shadow, but I'm
> > > not sure that counters the "horrible errata" statement ;-).  SMI+RSM saves
> > > and restores STI blocking in that case, but AFAICT NMI has no such
> > > protection and will effectively break the shadow on its IRET.
> > 
> > Ugh. I can't say I care deeply about Quark (ie never seemed to go
> > anywhere), but it's odd. I thought it was based on a Pentium core (or
> > i486+?). Are you saying those didn't do it either?
> 
> It's 486 based, but either way I suspect the answer is "yes".  IIRC,
> Knights Corner, a.k.a. Larrabee, also had funkiness around SMM and that
> was based on P54C, though I'm struggling to recall exactly what the
> Larrabee weirdness was.

Aha!  Found an ancient comment that explicitly states P5 does not block
NMI/SMI in the STI shadow, while P6 does block NMI/SMI.

  reply	other threads:[~2019-04-30  0:45 UTC|newest]

Thread overview: 192+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-04-27 10:06 [PATCH 0/4] x86/ftrace: make ftrace_int3_handler() not to skip fops invocation Nicolai Stange
2019-04-27 10:06 ` Nicolai Stange
2019-04-27 10:06 ` nstange
2019-04-27 10:06 ` [PATCH 1/4] x86/thread_info: introduce ->ftrace_int3_stack member Nicolai Stange
2019-04-27 10:06   ` Nicolai Stange
2019-04-27 10:06   ` nstange
2019-04-28 17:41   ` Andy Lutomirski
2019-04-28 17:41     ` Andy Lutomirski
2019-04-28 17:41     ` luto
2019-04-28 17:51     ` Steven Rostedt
2019-04-28 17:51       ` Steven Rostedt
2019-04-28 17:51       ` rostedt
2019-04-28 18:08       ` Andy Lutomirski
2019-04-28 18:08         ` Andy Lutomirski
2019-04-28 18:08         ` luto
2019-04-28 19:43         ` Steven Rostedt
2019-04-28 19:43           ` Steven Rostedt
2019-04-28 19:43           ` rostedt
2019-04-28 20:56           ` Andy Lutomirski
2019-04-28 20:56             ` Andy Lutomirski
2019-04-28 20:56             ` luto
2019-04-28 21:22       ` Nicolai Stange
2019-04-28 21:22         ` Nicolai Stange
2019-04-28 21:22         ` nstange
2019-04-28 23:27         ` Andy Lutomirski
2019-04-28 23:27           ` Andy Lutomirski
2019-04-28 23:27           ` luto
2019-04-27 10:06 ` [PATCH 2/4] ftrace: drop 'static' qualifier from ftrace_ops_list_func() Nicolai Stange
2019-04-27 10:06   ` Nicolai Stange
2019-04-27 10:06   ` nstange
2019-04-27 10:06 ` [PATCH 3/4] x86/ftrace: make ftrace_int3_handler() not to skip fops invocation Nicolai Stange
2019-04-27 10:06   ` Nicolai Stange
2019-04-27 10:06   ` nstange
2019-04-27 10:26   ` Peter Zijlstra
2019-04-27 10:26     ` Peter Zijlstra
2019-04-27 10:26     ` peterz
2019-04-28 17:38     ` Steven Rostedt
2019-04-28 17:38       ` Steven Rostedt
2019-04-28 17:38       ` rostedt
2019-04-29 18:06       ` Linus Torvalds
2019-04-29 18:06         ` Linus Torvalds
2019-04-29 18:06         ` torvalds
2019-04-29 18:22         ` Linus Torvalds
2019-04-29 18:22           ` Linus Torvalds
2019-04-29 18:22           ` torvalds
2019-04-29 18:42           ` Andy Lutomirski
2019-04-29 18:42             ` Andy Lutomirski
2019-04-29 18:42             ` luto
     [not found]             ` <CAHk-=whtt4K2f0KPtG-4Pykh3FK8UBOjD8jhXCUKB5nWDj_YRA@mail.gmail.com>
2019-04-29 18:56               ` Andy Lutomirski
2019-04-29 18:56                 ` Andy Lutomirski
2019-04-29 18:56                 ` luto
     [not found]                 ` <CAHk-=wgewK4eFhF3=0RNtk1KQjMANFH6oDE=8m=84RExn2gxhw@mail.gmail.com>
     [not found]                   ` <CAHk-=whay7eN6+2gZjY-ybRbkbcqAmgrLwwszzHx8ws3c=S-MA@mail.gmail.com>
2019-04-29 19:24                     ` Andy Lutomirski
2019-04-29 19:24                       ` Andy Lutomirski
2019-04-29 19:24                       ` luto
2019-04-29 20:07                       ` Linus Torvalds
2019-04-29 20:07                         ` Linus Torvalds
2019-04-29 20:07                         ` torvalds
2019-04-30 13:56                         ` Peter Zijlstra
2019-04-30 13:56                           ` Peter Zijlstra
2019-04-30 13:56                           ` peterz
2019-04-30 16:06                           ` Linus Torvalds
2019-04-30 16:06                             ` Linus Torvalds
2019-04-30 16:06                             ` torvalds
2019-04-30 16:33                             ` Andy Lutomirski
2019-04-30 16:33                               ` Andy Lutomirski
2019-04-30 16:33                               ` luto
2019-04-30 17:03                               ` Steven Rostedt
2019-04-30 17:03                                 ` Steven Rostedt
2019-04-30 17:03                                 ` rostedt
2019-04-30 17:20                                 ` Steven Rostedt
2019-04-30 17:20                                   ` Steven Rostedt
2019-04-30 17:20                                   ` rostedt
2019-04-30 17:49                                   ` [RFC][PATCH] ftrace/x86: Emulate call function while updating in breakpoint handler Steven Rostedt
2019-04-30 17:49                                     ` Steven Rostedt
2019-04-30 17:49                                     ` rostedt
2019-04-30 18:33                                     ` Linus Torvalds
2019-04-30 18:33                                       ` Linus Torvalds
2019-04-30 18:33                                       ` torvalds
2019-04-30 19:00                                       ` Steven Rostedt
2019-04-30 19:00                                         ` Steven Rostedt
2019-04-30 19:00                                         ` rostedt
2019-04-30 21:08                                       ` Steven Rostedt
2019-04-30 21:08                                         ` Steven Rostedt
2019-04-30 21:08                                         ` rostedt
2019-05-01 13:11                                       ` Peter Zijlstra
2019-05-01 13:11                                         ` Peter Zijlstra
2019-05-01 13:11                                         ` peterz
2019-05-01 18:58                                         ` Steven Rostedt
2019-05-01 18:58                                           ` Steven Rostedt
2019-05-01 18:58                                           ` rostedt
2019-05-01 19:03                                           ` Peter Zijlstra
2019-05-01 19:03                                             ` Peter Zijlstra
2019-05-01 19:03                                             ` peterz
2019-05-01 19:03                                         ` Linus Torvalds
2019-05-01 19:03                                           ` Linus Torvalds
2019-05-01 19:03                                           ` torvalds
2019-05-01 19:13                                           ` Peter Zijlstra
2019-05-01 19:13                                             ` Peter Zijlstra
2019-05-01 19:13                                             ` peterz
2019-05-01 19:13                                           ` Steven Rostedt
2019-05-01 19:13                                             ` Steven Rostedt
2019-05-01 19:13                                             ` rostedt
2019-05-01 19:33                                             ` Jiri Kosina
2019-05-01 19:33                                               ` Jiri Kosina
2019-05-01 19:33                                               ` jikos
2019-05-01 19:41                                               ` Peter Zijlstra
2019-05-01 19:41                                                 ` Peter Zijlstra
2019-05-01 19:41                                                 ` peterz
2019-04-30 21:53                                     ` [RFC][PATCH v2] " Steven Rostedt
2019-04-30 21:53                                       ` Steven Rostedt
2019-04-30 21:53                                       ` rostedt
2019-05-01  1:35                                       ` Steven Rostedt
2019-05-01  1:35                                         ` Steven Rostedt
2019-05-01  1:35                                         ` rostedt
2019-05-01  1:58                                         ` Linus Torvalds
2019-05-01  1:58                                           ` Linus Torvalds
2019-05-01  1:58                                           ` torvalds
2019-05-01  8:26                                       ` Nicolai Stange
2019-05-01  8:26                                         ` Nicolai Stange
2019-05-01  8:26                                         ` nstange
2019-05-01 13:22                                         ` Steven Rostedt
2019-05-01 13:22                                           ` Steven Rostedt
2019-05-01 13:22                                           ` rostedt
2019-04-29 20:16                   ` [PATCH 3/4] x86/ftrace: make ftrace_int3_handler() not to skip fops invocation Linus Torvalds
2019-04-29 20:16                     ` Linus Torvalds
2019-04-29 20:16                     ` torvalds
2019-04-29 22:08                     ` Sean Christopherson
2019-04-29 22:08                       ` Sean Christopherson
2019-04-29 22:08                       ` sean.j.christopherson
2019-04-29 22:22                       ` Linus Torvalds
2019-04-29 22:22                         ` Linus Torvalds
2019-04-29 22:22                         ` torvalds
2019-04-30  0:08                         ` Sean Christopherson
2019-04-30  0:08                           ` Sean Christopherson
2019-04-30  0:08                           ` sean.j.christopherson
2019-04-30  0:45                           ` Sean Christopherson [this message]
2019-04-30  0:45                             ` Sean Christopherson
2019-04-30  0:45                             ` sean.j.christopherson
2019-04-30  2:26                             ` Linus Torvalds
2019-04-30  2:26                               ` Linus Torvalds
2019-04-30  2:26                               ` torvalds
2019-04-30 10:40                               ` Peter Zijlstra
2019-04-30 10:40                                 ` Peter Zijlstra
2019-04-30 10:40                                 ` peterz
2019-04-30 11:17                               ` Jiri Kosina
2019-04-30 11:17                                 ` Jiri Kosina
2019-04-30 11:17                                 ` jikos
2019-04-29 22:06                 ` Linus Torvalds
2019-04-29 22:06                   ` Linus Torvalds
2019-04-29 22:06                   ` torvalds
2019-04-30 11:18                   ` Peter Zijlstra
2019-04-30 11:18                     ` Peter Zijlstra
2019-04-30 11:18                     ` peterz
2019-04-29 18:52         ` Steven Rostedt
2019-04-29 18:52           ` Steven Rostedt
2019-04-29 18:52           ` rostedt
     [not found]           ` <CAHk-=wjm93jLtVxTX4HZs6K4k1Wqh3ujjmapqaYtcibVk_YnzQ@mail.gmail.com>
2019-04-29 19:07             ` Steven Rostedt
2019-04-29 19:07               ` Steven Rostedt
2019-04-29 19:07               ` rostedt
2019-04-29 20:06               ` Linus Torvalds
2019-04-29 20:06                 ` Linus Torvalds
2019-04-29 20:06                 ` torvalds
2019-04-29 20:20                 ` Linus Torvalds
2019-04-29 20:20                   ` Linus Torvalds
2019-04-29 20:20                   ` torvalds
2019-04-29 20:30                 ` Steven Rostedt
2019-04-29 20:30                   ` Steven Rostedt
2019-04-29 20:30                   ` rostedt
2019-04-29 21:38                   ` Linus Torvalds
2019-04-29 21:38                     ` Linus Torvalds
2019-04-29 21:38                     ` torvalds
2019-04-29 22:07                     ` Steven Rostedt
2019-04-29 22:07                       ` Steven Rostedt
2019-04-29 22:07                       ` rostedt
2019-04-30  9:24                       ` Nicolai Stange
2019-04-30  9:24                         ` Nicolai Stange
2019-04-30  9:24                         ` nstange
2019-04-30 10:46           ` Peter Zijlstra
2019-04-30 10:46             ` Peter Zijlstra
2019-04-30 10:46             ` peterz
2019-04-30 13:44             ` Steven Rostedt
2019-04-30 13:44               ` Steven Rostedt
2019-04-30 13:44               ` rostedt
2019-04-30 14:20               ` Peter Zijlstra
2019-04-30 14:20                 ` Peter Zijlstra
2019-04-30 14:20                 ` peterz
2019-04-30 14:36                 ` Steven Rostedt
2019-04-30 14:36                   ` Steven Rostedt
2019-04-30 14:36                   ` rostedt
2019-04-27 10:06 ` [PATCH 4/4] selftests/livepatch: add "ftrace a live patched function" test Nicolai Stange
2019-04-27 10:06   ` Nicolai Stange
2019-04-27 10:06   ` nstange

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