From: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
To: Florian Weimer <fweimer@redhat.com>
Cc: carlos <carlos@redhat.com>, Peter Zijlstra <peterz@infradead.org>,
linux-kernel <linux-kernel@vger.kernel.org>,
Thomas Gleixner <tglx@linutronix.de>,
paulmck <paulmck@linux.ibm.com>,
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>
Subject: Re: [RFC PATCH 2/4] rseq: Allow extending struct rseq
Date: Wed, 15 Jul 2020 09:31:24 -0400 (EDT) [thread overview]
Message-ID: <882700738.14181.1594819884049.JavaMail.zimbra@efficios.com> (raw)
In-Reply-To: <87y2nk29rp.fsf@oldenburg2.str.redhat.com>
----- On Jul 15, 2020, at 9:22 AM, Florian Weimer fweimer@redhat.com wrote:
> * Mathieu Desnoyers:
>
>> Practically speaking, I suspect this would mean postponing availability of
>> rseq for widely deployed applications for a few more years ?
>
> There is no rseq support in GCC today, so you have to write assembler
> code anyway.
Assembler code is only needed for the rseq critical sections, not for accessing
the __rseq_abi. Use-cases like getting the current cpu number do not currently
require any assembler for instance.
So indeed it could be done today without upgrading the toolchains by writing
custom assembler for each architecture to get the thread's struct rseq. AFAIU
the ABI to access the thread pointer is fixed for each architecture, right ?
How would this allow early-rseq-adopter libraries to interact with glibc ?
Thanks,
Mathieu
--
Mathieu Desnoyers
EfficiOS Inc.
http://www.efficios.com
next prev parent reply other threads:[~2020-07-15 13:31 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-07-14 3:03 [RFC PATCH 0/4] rseq: Introduce extensible struct rseq Mathieu Desnoyers
2020-07-14 3:03 ` [RFC PATCH 1/4] selftests: rseq: Use fixed value as rseq_len parameter Mathieu Desnoyers
2020-07-14 3:03 ` [RFC PATCH 2/4] rseq: Allow extending struct rseq Mathieu Desnoyers
2020-07-14 9:58 ` Florian Weimer
2020-07-14 12:50 ` Mathieu Desnoyers
2020-07-14 13:00 ` Florian Weimer
2020-07-14 13:19 ` Mathieu Desnoyers
2020-07-14 21:30 ` Carlos O'Donell
2020-07-15 13:12 ` Mathieu Desnoyers
2020-07-15 13:22 ` Florian Weimer
2020-07-15 13:31 ` Mathieu Desnoyers [this message]
2020-07-15 13:42 ` Florian Weimer
2020-07-15 13:55 ` Christian Brauner
2020-07-15 14:20 ` Mathieu Desnoyers
2020-07-15 14:54 ` Mathieu Desnoyers
2020-07-15 14:58 ` Florian Weimer
2020-07-15 15:26 ` Mathieu Desnoyers
2020-07-14 17:24 ` Peter Oskolkov
2020-07-14 17:43 ` Mathieu Desnoyers
2020-07-14 18:33 ` Peter Oskolkov
2020-07-15 2:34 ` Chris Kennelly
2020-07-15 6:31 ` Florian Weimer
2020-07-15 10:59 ` Christian Brauner
2020-07-15 14:38 ` Mathieu Desnoyers
2020-07-15 14:50 ` Mathieu Desnoyers
2020-07-15 11:38 ` Christian Brauner
2020-07-15 12:33 ` Christian Brauner
2020-07-15 15:10 ` Mathieu Desnoyers
2020-07-15 15:33 ` Christian Brauner
2020-07-14 3:03 ` [RFC PATCH 3/4] selftests: rseq: define __rseq_abi with extensible size Mathieu Desnoyers
2020-07-14 3:03 ` [RFC PATCH 4/4] selftests: rseq: print rseq extensible size in basic test Mathieu Desnoyers
2020-07-14 20:55 ` [RFC PATCH 0/4] rseq: Introduce extensible struct rseq Carlos O'Donell
2020-07-15 13:02 ` Mathieu Desnoyers
2020-07-16 13:39 ` Carlos O'Donell
2020-07-16 14:45 ` Mathieu Desnoyers
2020-07-15 15:12 ` Florian Weimer
2020-07-15 15:32 ` Mathieu Desnoyers
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