From: peterz at infradead.org (Peter Zijlstra)
Subject: [RFC][PATCH v3] ftrace/x86_64: Emulate call function while updating in breakpoint handler
Date: Wed, 1 May 2019 20:57:26 +0200 [thread overview]
Message-ID: <20190501185726.GR7905@worktop.programming.kicks-ass.net> (raw)
In-Reply-To: <CAHk-=wjvQxY4DvPrJ6haPgAa6b906h=MwZXO6G8OtiTGe=N7_w@mail.gmail.com>
On Wed, May 01, 2019 at 11:01:07AM -0700, Linus Torvalds wrote:
> This looks sane to me, although I'm surprised that we didn't already
> have an annotation for the nonstandard stack frame for asm files. That
> probably would be cleaner in a separate commit, but I guess it doesn't
> matter.
>
> Anyway, I'm willing to consider the entry code version if it looks a
> _lot_ simpler than this (so I'd like to see them side-by-side), but
> it's not like this looks all that complicated to me either.
So I posted one earlier today:
https://lkml.kernel.org/r/20190501131117.GW2623 at hirez.programming.kicks-ass.net
it's about a 1/3rd the number of lines and has 32bit support. It also
provides all the bits required to implement static_call().
That is; I think I'm firmly in favour of the entry variant -- provided
it actually works of course.
WARNING: multiple messages have this Message-ID (diff)
From: peterz@infradead.org (Peter Zijlstra)
Subject: [RFC][PATCH v3] ftrace/x86_64: Emulate call function while updating in breakpoint handler
Date: Wed, 1 May 2019 20:57:26 +0200 [thread overview]
Message-ID: <20190501185726.GR7905@worktop.programming.kicks-ass.net> (raw)
Message-ID: <20190501185726.VCRmZ7evLLjbPL_XVQfQOm6xxtETizz5kl7aMDrAh_I@z> (raw)
In-Reply-To: <CAHk-=wjvQxY4DvPrJ6haPgAa6b906h=MwZXO6G8OtiTGe=N7_w@mail.gmail.com>
On Wed, May 01, 2019@11:01:07AM -0700, Linus Torvalds wrote:
> This looks sane to me, although I'm surprised that we didn't already
> have an annotation for the nonstandard stack frame for asm files. That
> probably would be cleaner in a separate commit, but I guess it doesn't
> matter.
>
> Anyway, I'm willing to consider the entry code version if it looks a
> _lot_ simpler than this (so I'd like to see them side-by-side), but
> it's not like this looks all that complicated to me either.
So I posted one earlier today:
https://lkml.kernel.org/r/20190501131117.GW2623 at hirez.programming.kicks-ass.net
it's about a 1/3rd the number of lines and has 32bit support. It also
provides all the bits required to implement static_call().
That is; I think I'm firmly in favour of the entry variant -- provided
it actually works of course.
WARNING: multiple messages have this Message-ID (diff)
From: Peter Zijlstra <peterz@infradead.org>
To: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Steven Rostedt <rostedt@goodmis.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>,
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: [RFC][PATCH v3] ftrace/x86_64: Emulate call function while updating in breakpoint handler
Date: Wed, 1 May 2019 20:57:26 +0200 [thread overview]
Message-ID: <20190501185726.GR7905@worktop.programming.kicks-ass.net> (raw)
In-Reply-To: <CAHk-=wjvQxY4DvPrJ6haPgAa6b906h=MwZXO6G8OtiTGe=N7_w@mail.gmail.com>
On Wed, May 01, 2019 at 11:01:07AM -0700, Linus Torvalds wrote:
> This looks sane to me, although I'm surprised that we didn't already
> have an annotation for the nonstandard stack frame for asm files. That
> probably would be cleaner in a separate commit, but I guess it doesn't
> matter.
>
> Anyway, I'm willing to consider the entry code version if it looks a
> _lot_ simpler than this (so I'd like to see them side-by-side), but
> it's not like this looks all that complicated to me either.
So I posted one earlier today:
https://lkml.kernel.org/r/20190501131117.GW2623@hirez.programming.kicks-ass.net
it's about a 1/3rd the number of lines and has 32bit support. It also
provides all the bits required to implement static_call().
That is; I think I'm firmly in favour of the entry variant -- provided
it actually works of course.
next prev parent reply other threads:[~2019-05-01 18:57 UTC|newest]
Thread overview: 24+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-05-01 15:32 [RFC][PATCH v3] ftrace/x86_64: Emulate call function while updating in breakpoint handler rostedt
2019-05-01 15:32 ` Steven Rostedt
2019-05-01 15:32 ` Steven Rostedt
2019-05-01 18:01 ` torvalds
2019-05-01 18:01 ` Linus Torvalds
2019-05-01 18:01 ` Linus Torvalds
2019-05-01 18:52 ` rostedt
2019-05-01 18:52 ` Steven Rostedt
2019-05-01 18:52 ` Steven Rostedt
2019-05-01 18:59 ` torvalds
2019-05-01 18:59 ` Linus Torvalds
2019-05-01 18:59 ` Linus Torvalds
2019-05-01 19:17 ` peterz
2019-05-01 19:17 ` Peter Zijlstra
2019-05-01 19:17 ` Peter Zijlstra
2019-05-01 19:36 ` torvalds
2019-05-01 19:36 ` Linus Torvalds
2019-05-01 19:36 ` Linus Torvalds
2019-05-01 18:57 ` peterz [this message]
2019-05-01 18:57 ` Peter Zijlstra
2019-05-01 18:57 ` Peter Zijlstra
2019-05-01 19:00 ` rostedt
2019-05-01 19:00 ` Steven Rostedt
2019-05-01 19:00 ` Steven Rostedt
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