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From: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
To: Florian Weimer <fw@deneb.enyo.de>
Cc: Peter Zijlstra <peterz@infradead.org>,
	linux-kernel <linux-kernel@vger.kernel.org>,
	Thomas Gleixner <tglx@linutronix.de>,
	paulmck <paulmck@kernel.org>, Boqun Feng <boqun.feng@gmail.com>,
	"H. Peter Anvin" <hpa@zytor.com>, Paul Turner <pjt@google.com>,
	linux-api <linux-api@vger.kernel.org>,
	Christian Brauner <christian.brauner@ubuntu.com>,
	carlos <carlos@redhat.com>
Subject: Re: [RFC PATCH] rseq: x86: implement abort-at-ip extension
Date: Wed, 12 Jan 2022 11:38:05 -0500 (EST)	[thread overview]
Message-ID: <396330808.24806.1642005485899.JavaMail.zimbra@efficios.com> (raw)
In-Reply-To: <87sftt6j0u.fsf@mid.deneb.enyo.de>

----- On Jan 12, 2022, at 11:00 AM, Florian Weimer fw@deneb.enyo.de wrote:

> * Peter Zijlstra:
> 
>> On Wed, Jan 12, 2022 at 04:16:36PM +0100, Florian Weimer wrote:
>>
>>> You could perhaps push a signal frame onto the stack.  It's going to
>>> be expensive, but it's already in the context switch path, so maybe it
>>> does not matter.
>>
>> Please no! Signals are a trainwreck that need change (see the whole
>> AVX-512 / AMX saga), we shouldn't use more of that just cause.
> 
> If it's a signal, it should be modeled as such.  I think it's pretty
> close to a synchronous signal.

Florian, just to validate here: is your argument about AVX-512/AMX or about
rseq abort-at-ip ?

Am I understanding correctly that you would prefer that the kernel push an entire
signal frame onto the stack rather than just push the abort-at-ip value
on abort ? If it is the case, are there advantages in doing so ? Tooling support ?

Thanks,

Mathieu

-- 
Mathieu Desnoyers
EfficiOS Inc.
http://www.efficios.com

  reply	other threads:[~2022-01-12 16:38 UTC|newest]

Thread overview: 15+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-01-07 17:03 [RFC PATCH] rseq: x86: implement abort-at-ip extension Mathieu Desnoyers
2022-01-07 19:31 ` Florian Weimer
2022-01-07 19:48   ` Mathieu Desnoyers
2022-01-07 21:27     ` Mathieu Desnoyers
2022-01-07 22:27       ` David Laight
2022-01-08  1:08         ` Mathieu Desnoyers
2022-01-08  1:33           ` Mathieu Desnoyers
2022-01-08  1:33           ` Mathieu Desnoyers
2022-01-12 15:16     ` Florian Weimer
2022-01-12 15:26       ` Mathieu Desnoyers
2022-01-12 15:38       ` Peter Zijlstra
2022-01-12 16:00         ` Florian Weimer
2022-01-12 16:38           ` Mathieu Desnoyers [this message]
2022-01-12 21:00             ` Florian Weimer
2022-01-12 21:24               ` Mathieu Desnoyers

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