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From: Peter Zijlstra <peterz@infradead.org>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Steven Rostedt <rostedt@goodmis.org>,
	Linux List Kernel Mailing <linux-kernel@vger.kernel.org>,
	Ingo Molnar <mingo@kernel.org>,
	Andrew Morton <akpm@linux-foundation.org>,
	Andy Lutomirski <luto@kernel.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>,
	"open list:KERNEL SELFTEST FRAMEWORK" 
	<linux-kselftest@vger.kernel.org>,
	stable <stable@vger.kernel.org>
Subject: Re: [RFC][PATCH 1/2] x86: Allow breakpoints to emulate call functions
Date: Thu, 2 May 2019 23:32:39 +0200	[thread overview]
Message-ID: <20190502213239.GA2623@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <CAHk-=wh8bi5c_GkyjPtDAiaXaZRqtmhWs30usUvs4qK_F+c9tg@mail.gmail.com>

On Thu, May 02, 2019 at 01:49:29PM -0700, Linus Torvalds wrote:

> We *could* also make this kernel-mode-only do_int3() be a special
> function, and do something like

I think I prefer the variant we have now. The int3_emulate_*() things
work uniformly and as expected on 32 and 64 bit (it would even work for
userspace if it weren't for SMAP).

So while the 32bit kernel entry is 'special' all the INT3 handlers can
uniformly prod at pt_regs in a natural way and have it work.

Making it special -- just for 32bit, seems like the wrong thing to me.

WARNING: multiple messages have this Message-ID (diff)
From: peterz at infradead.org (Peter Zijlstra)
Subject: [RFC][PATCH 1/2] x86: Allow breakpoints to emulate call functions
Date: Thu, 2 May 2019 23:32:39 +0200	[thread overview]
Message-ID: <20190502213239.GA2623@hirez.programming.kicks-ass.net> (raw)
In-Reply-To: <CAHk-=wh8bi5c_GkyjPtDAiaXaZRqtmhWs30usUvs4qK_F+c9tg@mail.gmail.com>

On Thu, May 02, 2019 at 01:49:29PM -0700, Linus Torvalds wrote:

> We *could* also make this kernel-mode-only do_int3() be a special
> function, and do something like

I think I prefer the variant we have now. The int3_emulate_*() things
work uniformly and as expected on 32 and 64 bit (it would even work for
userspace if it weren't for SMAP).

So while the 32bit kernel entry is 'special' all the INT3 handlers can
uniformly prod at pt_regs in a natural way and have it work.

Making it special -- just for 32bit, seems like the wrong thing to me.

WARNING: multiple messages have this Message-ID (diff)
From: peterz@infradead.org (Peter Zijlstra)
Subject: [RFC][PATCH 1/2] x86: Allow breakpoints to emulate call functions
Date: Thu, 2 May 2019 23:32:39 +0200	[thread overview]
Message-ID: <20190502213239.GA2623@hirez.programming.kicks-ass.net> (raw)
Message-ID: <20190502213239.-ml9DYNfNKrljYVH_t1_8mnWfgAxx-wYUdu_GA5Dgog@z> (raw)
In-Reply-To: <CAHk-=wh8bi5c_GkyjPtDAiaXaZRqtmhWs30usUvs4qK_F+c9tg@mail.gmail.com>

On Thu, May 02, 2019@01:49:29PM -0700, Linus Torvalds wrote:

> We *could* also make this kernel-mode-only do_int3() be a special
> function, and do something like

I think I prefer the variant we have now. The int3_emulate_*() things
work uniformly and as expected on 32 and 64 bit (it would even work for
userspace if it weren't for SMAP).

So while the 32bit kernel entry is 'special' all the INT3 handlers can
uniformly prod at pt_regs in a natural way and have it work.

Making it special -- just for 32bit, seems like the wrong thing to me.

  reply	other threads:[~2019-05-02 21:33 UTC|newest]

Thread overview: 307+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-05-01 20:28 [RFC][PATCH 0/2] ftrace/x86: Allow for breakpoint handlers to emulate call functions Steven Rostedt
2019-05-01 20:28 ` [RFC][PATCH 1/2] x86: Allow breakpoints " Steven Rostedt
2019-05-01 20:28   ` Steven Rostedt
2019-05-01 20:28   ` rostedt
2019-05-02  3:24   ` Steven Rostedt
2019-05-02  3:24     ` Steven Rostedt
2019-05-02  3:24     ` rostedt
2019-05-02 16:21     ` Peter Zijlstra
2019-05-02 16:21       ` Peter Zijlstra
2019-05-02 16:21       ` peterz
2019-05-02 16:29       ` Peter Zijlstra
2019-05-02 16:29         ` Peter Zijlstra
2019-05-02 16:29         ` peterz
2019-05-02 18:02       ` Linus Torvalds
2019-05-02 18:02         ` Linus Torvalds
2019-05-02 18:02         ` torvalds
2019-05-02 18:18         ` Peter Zijlstra
2019-05-02 18:18           ` Peter Zijlstra
2019-05-02 18:18           ` peterz
2019-05-02 18:30           ` Peter Zijlstra
2019-05-02 18:30             ` Peter Zijlstra
2019-05-02 18:30             ` peterz
2019-05-02 18:43           ` Linus Torvalds
2019-05-02 18:43             ` Linus Torvalds
2019-05-02 18:43             ` torvalds
2019-05-02 19:28             ` Jiri Kosina
2019-05-02 19:28               ` Jiri Kosina
2019-05-02 19:28               ` jikos
2019-05-02 20:25               ` Andy Lutomirski
2019-05-02 20:25                 ` Andy Lutomirski
2019-05-02 20:25                 ` luto
2019-05-02 20:21             ` Peter Zijlstra
2019-05-02 20:21               ` Peter Zijlstra
2019-05-02 20:21               ` peterz
2019-05-02 20:49               ` Linus Torvalds
2019-05-02 20:49                 ` Linus Torvalds
2019-05-02 20:49                 ` torvalds
2019-05-02 21:32                 ` Peter Zijlstra [this message]
2019-05-02 21:32                   ` Peter Zijlstra
2019-05-02 21:32                   ` peterz
2019-05-03 19:24                 ` Steven Rostedt
2019-05-03 19:24                   ` Steven Rostedt
2019-05-03 19:24                   ` rostedt
2019-05-03 21:46                   ` Linus Torvalds
2019-05-03 21:46                     ` Linus Torvalds
2019-05-03 21:46                     ` torvalds
2019-05-03 22:49                     ` Steven Rostedt
2019-05-03 22:49                       ` Steven Rostedt
2019-05-03 22:49                       ` rostedt
2019-05-03 23:07                       ` Linus Torvalds
2019-05-03 23:07                         ` Linus Torvalds
2019-05-03 23:07                         ` torvalds
2019-05-04  4:17                         ` Steven Rostedt
2019-05-04  4:17                           ` Steven Rostedt
2019-05-04  4:17                           ` rostedt
     [not found]                           ` <CAHk-=wiuSFbv_rELND-BLWcP0GSZ0yF=xOAEcf61GE3bU9d=yg@mail.gmail.com>
2019-05-04 18:59                             ` Linus Torvalds
2019-05-04 18:59                               ` Linus Torvalds
2019-05-04 18:59                               ` torvalds
2019-05-04 20:12                               ` Andy Lutomirski
2019-05-04 20:12                                 ` Andy Lutomirski
2019-05-04 20:12                                 ` luto
2019-05-04 20:28                                 ` Linus Torvalds
2019-05-04 20:28                                   ` Linus Torvalds
2019-05-04 20:28                                   ` torvalds
2019-05-04 20:36                                 ` Linus Torvalds
2019-05-04 20:36                                   ` Linus Torvalds
2019-05-04 20:36                                   ` torvalds
2019-05-03 22:55                     ` Andy Lutomirski
2019-05-03 22:55                       ` Andy Lutomirski
2019-05-03 22:55                       ` luto
2019-05-03 23:16                       ` Linus Torvalds
2019-05-03 23:16                         ` Linus Torvalds
2019-05-03 23:16                         ` torvalds
2019-05-03 23:32                         ` Andy Lutomirski
2019-05-03 23:32                           ` Andy Lutomirski
2019-05-03 23:32                           ` luto
2019-05-02 22:52               ` Steven Rostedt
2019-05-02 22:52                 ` Steven Rostedt
2019-05-02 22:52                 ` rostedt
2019-05-02 23:31                 ` Steven Rostedt
2019-05-02 23:31                   ` Steven Rostedt
2019-05-02 23:31                   ` rostedt
2019-05-02 23:50                   ` Steven Rostedt
2019-05-02 23:50                     ` Steven Rostedt
2019-05-02 23:50                     ` rostedt
2019-05-03  1:51                     ` [RFC][PATCH 1/2 v2] " Steven Rostedt
2019-05-03  1:51                       ` Steven Rostedt
2019-05-03  1:51                       ` rostedt
2019-05-03  9:29                     ` [RFC][PATCH 1/2] " Peter Zijlstra
2019-05-03  9:29                       ` Peter Zijlstra
2019-05-03  9:29                       ` peterz
2019-05-03 13:22                       ` Steven Rostedt
2019-05-03 13:22                         ` Steven Rostedt
2019-05-03 13:22                         ` rostedt
2019-05-03 16:20                         ` Andy Lutomirski
2019-05-03 16:20                           ` Andy Lutomirski
2019-05-03 16:20                           ` luto
2019-05-03 16:31                           ` Steven Rostedt
2019-05-03 16:31                             ` Steven Rostedt
2019-05-03 16:31                             ` rostedt
2019-05-03 16:35                             ` Peter Zijlstra
2019-05-03 16:35                               ` Peter Zijlstra
2019-05-03 16:35                               ` peterz
2019-05-03 16:44                               ` Andy Lutomirski
2019-05-03 16:44                                 ` Andy Lutomirski
2019-05-03 16:44                                 ` luto
2019-05-03 16:49                                 ` Steven Rostedt
2019-05-03 16:49                                   ` Steven Rostedt
2019-05-03 16:49                                   ` rostedt
2019-05-03 16:32                           ` Peter Zijlstra
2019-05-03 16:32                             ` Peter Zijlstra
2019-05-03 16:32                             ` peterz
2019-05-03 18:57                           ` Linus Torvalds
2019-05-03 18:57                             ` Linus Torvalds
2019-05-03 18:57                             ` torvalds
2019-05-06  8:19                             ` Peter Zijlstra
2019-05-06  8:19                               ` Peter Zijlstra
2019-05-06  8:19                               ` peterz
2019-05-06 13:56                               ` Steven Rostedt
2019-05-06 13:56                                 ` Steven Rostedt
2019-05-06 13:56                                 ` rostedt
2019-05-06 16:17                                 ` Linus Torvalds
2019-05-06 16:17                                   ` Linus Torvalds
2019-05-06 16:17                                   ` torvalds
2019-05-06 16:19                                   ` Linus Torvalds
2019-05-06 16:19                                     ` Linus Torvalds
2019-05-06 16:19                                     ` torvalds
2019-05-06 17:06                                   ` Steven Rostedt
2019-05-06 17:06                                     ` Steven Rostedt
2019-05-06 17:06                                     ` rostedt
2019-05-06 18:06                                     ` Linus Torvalds
2019-05-06 18:06                                       ` Linus Torvalds
2019-05-06 18:06                                       ` torvalds
2019-05-06 18:57                                       ` Steven Rostedt
2019-05-06 18:57                                         ` Steven Rostedt
2019-05-06 18:57                                         ` rostedt
2019-05-06 19:46                                         ` Linus Torvalds
2019-05-06 19:46                                           ` Linus Torvalds
2019-05-06 19:46                                           ` torvalds
2019-05-06 20:29                                           ` Steven Rostedt
2019-05-06 20:29                                             ` Steven Rostedt
2019-05-06 20:29                                             ` rostedt
2019-05-06 20:42                                             ` Linus Torvalds
2019-05-06 20:42                                               ` Linus Torvalds
2019-05-06 20:42                                               ` torvalds
2019-05-06 20:44                                               ` Linus Torvalds
2019-05-06 20:44                                                 ` Linus Torvalds
2019-05-06 20:44                                                 ` torvalds
2019-05-06 21:45                                               ` Steven Rostedt
2019-05-06 21:45                                                 ` Steven Rostedt
2019-05-06 21:45                                                 ` rostedt
2019-05-06 22:06                                                 ` Linus Torvalds
2019-05-06 22:06                                                   ` Linus Torvalds
2019-05-06 22:06                                                   ` torvalds
2019-05-06 22:31                                                   ` Linus Torvalds
2019-05-06 22:31                                                     ` Linus Torvalds
2019-05-06 22:31                                                     ` torvalds
2019-05-07  0:10                                                     ` Steven Rostedt
2019-05-07  0:10                                                       ` Steven Rostedt
2019-05-07  0:10                                                       ` rostedt
2019-05-07  1:06                                                       ` Linus Torvalds
2019-05-07  1:06                                                         ` Linus Torvalds
2019-05-07  1:06                                                         ` torvalds
2019-05-07  1:04                                                   ` Steven Rostedt
2019-05-07  1:04                                                     ` Steven Rostedt
2019-05-07  1:04                                                     ` rostedt
2019-05-07  1:34                                                     ` Steven Rostedt
2019-05-07  1:34                                                       ` Steven Rostedt
2019-05-07  1:34                                                       ` rostedt
2019-05-07  1:34                                                     ` Linus Torvalds
2019-05-07  1:34                                                       ` Linus Torvalds
2019-05-07  1:34                                                       ` torvalds
2019-05-07  1:53                                                       ` Steven Rostedt
2019-05-07  1:53                                                         ` Steven Rostedt
2019-05-07  1:53                                                         ` rostedt
2019-05-07  2:22                                                         ` Linus Torvalds
2019-05-07  2:22                                                           ` Linus Torvalds
2019-05-07  2:22                                                           ` torvalds
2019-05-07  2:58                                                           ` Steven Rostedt
2019-05-07  2:58                                                             ` Steven Rostedt
2019-05-07  2:58                                                             ` rostedt
2019-05-07  3:05                                                             ` Linus Torvalds
2019-05-07  3:05                                                               ` Linus Torvalds
2019-05-07  3:05                                                               ` torvalds
2019-05-07  3:21                                                               ` Steven Rostedt
2019-05-07  3:21                                                                 ` Steven Rostedt
2019-05-07  3:21                                                                 ` rostedt
2019-05-07  3:28                                                                 ` Linus Torvalds
2019-05-07  3:28                                                                   ` Linus Torvalds
2019-05-07  3:28                                                                   ` torvalds
2019-05-07 14:54                                                                   ` Linus Torvalds
2019-05-07 14:54                                                                     ` Linus Torvalds
2019-05-07 14:54                                                                     ` torvalds
2019-05-07 15:12                                                                     ` Steven Rostedt
2019-05-07 15:12                                                                       ` Steven Rostedt
2019-05-07 15:12                                                                       ` rostedt
2019-05-07 15:25                                                                       ` Steven Rostedt
2019-05-07 15:25                                                                         ` Steven Rostedt
2019-05-07 15:25                                                                         ` rostedt
2019-05-07 16:25                                                                         ` Steven Rostedt
2019-05-07 16:25                                                                           ` Steven Rostedt
2019-05-07 16:25                                                                           ` rostedt
2019-05-07 15:31                                                                       ` Linus Torvalds
2019-05-07 15:31                                                                         ` Linus Torvalds
2019-05-07 15:31                                                                         ` torvalds
2019-05-07 15:45                                                                         ` Steven Rostedt
2019-05-07 15:45                                                                           ` Steven Rostedt
2019-05-07 15:45                                                                           ` rostedt
2019-05-07 16:34                                                                         ` Peter Zijlstra
2019-05-07 16:34                                                                           ` Peter Zijlstra
2019-05-07 16:34                                                                           ` peterz
2019-05-07 17:08                                                                           ` Linus Torvalds
2019-05-07 17:08                                                                             ` Linus Torvalds
2019-05-07 17:08                                                                             ` torvalds
2019-05-07 17:21                                                                             ` Josh Poimboeuf
2019-05-07 17:21                                                                               ` Josh Poimboeuf
2019-05-07 17:21                                                                               ` jpoimboe
2019-05-07 21:24                                                                               ` Steven Rostedt
2019-05-07 21:24                                                                                 ` Steven Rostedt
2019-05-07 21:24                                                                                 ` rostedt
2019-05-08  4:50                                                                                 ` Linus Torvalds
2019-05-08  4:50                                                                                   ` Linus Torvalds
2019-05-08  4:50                                                                                   ` torvalds
2019-05-08 16:37                                                                                   ` Steven Rostedt
2019-05-08 16:37                                                                                     ` Steven Rostedt
2019-05-08 16:37                                                                                     ` rostedt
2019-05-07 17:38                                                                             ` Peter Zijlstra
2019-05-07 17:38                                                                               ` Peter Zijlstra
2019-05-07 17:38                                                                               ` peterz
2019-05-07  9:51                                                           ` Peter Zijlstra
2019-05-07  9:51                                                             ` Peter Zijlstra
2019-05-07  9:51                                                             ` peterz
2019-05-07 14:48                                                           ` Andy Lutomirski
2019-05-07 14:48                                                             ` Andy Lutomirski
2019-05-07 14:48                                                             ` luto
2019-05-07 14:57                                                             ` Linus Torvalds
2019-05-07 14:57                                                               ` Linus Torvalds
2019-05-07 14:57                                                               ` torvalds
2019-05-07 14:13                                                 ` Masami Hiramatsu
2019-05-07 14:13                                                   ` Masami Hiramatsu
2019-05-07 14:13                                                   ` mhiramat
2019-05-07 17:15                                                   ` Masami Hiramatsu
2019-05-07 17:15                                                     ` Masami Hiramatsu
2019-05-07 17:15                                                     ` mhiramat
2019-05-06 14:22                               ` Peter Zijlstra
2019-05-06 14:22                                 ` Peter Zijlstra
2019-05-06 14:22                                 ` peterz
2019-05-07  8:57                               ` Peter Zijlstra
2019-05-07  8:57                                 ` Peter Zijlstra
2019-05-07  8:57                                 ` peterz
2019-05-07  9:18                                 ` David Laight
2019-05-07  9:18                                   ` David Laight
2019-05-07  9:18                                   ` David.Laight
2019-05-07 11:30                                   ` Peter Zijlstra
2019-05-07 11:30                                     ` Peter Zijlstra
2019-05-07 11:30                                     ` peterz
2019-05-07 12:57                                     ` David Laight
2019-05-07 12:57                                       ` David Laight
2019-05-07 12:57                                       ` David.Laight
2019-05-07 13:14                                       ` Steven Rostedt
2019-05-07 13:14                                         ` Steven Rostedt
2019-05-07 13:14                                         ` rostedt
2019-05-07 14:50                                         ` David Laight
2019-05-07 14:50                                           ` David Laight
2019-05-07 14:50                                           ` David.Laight
2019-05-07 14:57                                           ` Steven Rostedt
2019-05-07 14:57                                             ` Steven Rostedt
2019-05-07 14:57                                             ` rostedt
2019-05-07 15:46                                             ` David Laight
2019-05-07 15:46                                               ` David Laight
2019-05-07 15:46                                               ` David.Laight
2019-05-07 13:32                                       ` Peter Zijlstra
2019-05-07 13:32                                         ` Peter Zijlstra
2019-05-07 13:32                                         ` peterz
2019-05-07  9:27                                 ` Peter Zijlstra
2019-05-07  9:27                                   ` Peter Zijlstra
2019-05-07  9:27                                   ` peterz
2019-05-07 12:27                                   ` Steven Rostedt
2019-05-07 12:27                                     ` Steven Rostedt
2019-05-07 12:27                                     ` rostedt
2019-05-07 12:41                                     ` Peter Zijlstra
2019-05-07 12:41                                       ` Peter Zijlstra
2019-05-07 12:41                                       ` peterz
2019-05-07 12:54                                       ` Steven Rostedt
2019-05-07 12:54                                         ` Steven Rostedt
2019-05-07 12:54                                         ` rostedt
2019-05-07 17:22                                         ` Masami Hiramatsu
2019-05-07 17:22                                           ` Masami Hiramatsu
2019-05-07 17:22                                           ` masami.hiramatsu
2019-05-07 14:28                                 ` Peter Zijlstra
2019-05-07 14:28                                   ` Peter Zijlstra
2019-05-07 14:28                                   ` peterz
2019-05-02 20:48         ` Steven Rostedt
2019-05-02 20:48           ` Steven Rostedt
2019-05-02 20:48           ` rostedt
2019-05-06 15:14         ` Josh Poimboeuf
2019-05-06 15:14           ` Josh Poimboeuf
2019-05-06 15:14           ` jpoimboe
2019-05-01 20:28 ` [RFC][PATCH 2/2] ftrace/x86: Emulate call function while updating in breakpoint handler Steven Rostedt
2019-05-01 20:28   ` Steven Rostedt
2019-05-01 20:28   ` rostedt
2019-05-03 10:22 ` [RFC][PATCH 1.5/2] x86: Add int3_emulate_call() selftest Peter Zijlstra
2019-05-03 10:22   ` Peter Zijlstra
2019-05-03 10:22   ` peterz
2019-05-03 18:46   ` Steven Rostedt
2019-05-03 18:46     ` Steven Rostedt
2019-05-03 18:46     ` rostedt

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