From: Linus Torvalds <torvalds@linux-foundation.org>
To: Steven Rostedt <rostedt@goodmis.org>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>,
Peter Zijlstra <peterz@infradead.org>,
Andy Lutomirski <luto@amacapital.net>,
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>,
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>,
Masami Hiramatsu <mhiramat@kernel.org>
Subject: Re: [RFC][PATCH 1/2] x86: Allow breakpoints to emulate call functions
Date: Tue, 7 May 2019 21:50:52 -0700 [thread overview]
Message-ID: <CAHk-=wg5_fwx_-ybD9TLQE4rAUqtYzO2CAmpciWTkDn3dtKMOw@mail.gmail.com> (raw)
In-Reply-To: <20190507172418.67ef6fc3@gandalf.local.home>
On Tue, May 7, 2019 at 2:24 PM Steven Rostedt <rostedt@goodmis.org> wrote:
>
> And there's been several times I forget that regs->sp can not be read
> directly. Especially most of my bug reports are for x86_64 these days.
> But when I had that seldom x86_32 one, and go debugging, I would print
> out "regs->sp" and then the system would crash. And I spend some time
> wondering why?
>
> It's been a bane of mine for some time.
Guys, I have basically a one-liner patch for your hangups.
It's called "rename 'sp' to 'user_sp' on x86-32".
Then we make the 'sp' field on x86-64 be a union, so that you can call
it user_sp or sp as you wish.
Yeah, it's really more than one line, because obviously the users will
need chaning, but honestly, that would be a _real_ cleanup. Make the
register match what it actually is.
And it doesn't mess up the stack frame, and it doesn't change the
entry code. It just reminds people that the entry is the USER stack
pointer.
Problem solved.
Linus
WARNING: multiple messages have this Message-ID (diff)
From: torvalds at linux-foundation.org (Linus Torvalds)
Subject: [RFC][PATCH 1/2] x86: Allow breakpoints to emulate call functions
Date: Tue, 7 May 2019 21:50:52 -0700 [thread overview]
Message-ID: <CAHk-=wg5_fwx_-ybD9TLQE4rAUqtYzO2CAmpciWTkDn3dtKMOw@mail.gmail.com> (raw)
In-Reply-To: <20190507172418.67ef6fc3@gandalf.local.home>
On Tue, May 7, 2019 at 2:24 PM Steven Rostedt <rostedt at goodmis.org> wrote:
>
> And there's been several times I forget that regs->sp can not be read
> directly. Especially most of my bug reports are for x86_64 these days.
> But when I had that seldom x86_32 one, and go debugging, I would print
> out "regs->sp" and then the system would crash. And I spend some time
> wondering why?
>
> It's been a bane of mine for some time.
Guys, I have basically a one-liner patch for your hangups.
It's called "rename 'sp' to 'user_sp' on x86-32".
Then we make the 'sp' field on x86-64 be a union, so that you can call
it user_sp or sp as you wish.
Yeah, it's really more than one line, because obviously the users will
need chaning, but honestly, that would be a _real_ cleanup. Make the
register match what it actually is.
And it doesn't mess up the stack frame, and it doesn't change the
entry code. It just reminds people that the entry is the USER stack
pointer.
Problem solved.
Linus
WARNING: multiple messages have this Message-ID (diff)
From: torvalds@linux-foundation.org (Linus Torvalds)
Subject: [RFC][PATCH 1/2] x86: Allow breakpoints to emulate call functions
Date: Tue, 7 May 2019 21:50:52 -0700 [thread overview]
Message-ID: <CAHk-=wg5_fwx_-ybD9TLQE4rAUqtYzO2CAmpciWTkDn3dtKMOw@mail.gmail.com> (raw)
Message-ID: <20190508045052.vG-NUIKYYcc4_SwhOKj1tqdFt2jbX4gJudfhTXxfQqA@z> (raw)
In-Reply-To: <20190507172418.67ef6fc3@gandalf.local.home>
On Tue, May 7, 2019@2:24 PM Steven Rostedt <rostedt@goodmis.org> wrote:
>
> And there's been several times I forget that regs->sp can not be read
> directly. Especially most of my bug reports are for x86_64 these days.
> But when I had that seldom x86_32 one, and go debugging, I would print
> out "regs->sp" and then the system would crash. And I spend some time
> wondering why?
>
> It's been a bane of mine for some time.
Guys, I have basically a one-liner patch for your hangups.
It's called "rename 'sp' to 'user_sp' on x86-32".
Then we make the 'sp' field on x86-64 be a union, so that you can call
it user_sp or sp as you wish.
Yeah, it's really more than one line, because obviously the users will
need chaning, but honestly, that would be a _real_ cleanup. Make the
register match what it actually is.
And it doesn't mess up the stack frame, and it doesn't change the
entry code. It just reminds people that the entry is the USER stack
pointer.
Problem solved.
Linus
next prev parent reply other threads:[~2019-05-08 4:51 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
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 [this message]
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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