All of lore.kernel.org
 help / color / mirror / Atom feed
From: Florian Weimer <fweimer@redhat.com>
To: Mathieu Desnoyers <mathieu.desnoyers@efficios.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 15:42:11 +0200	[thread overview]
Message-ID: <87mu4028uk.fsf@oldenburg2.str.redhat.com> (raw)
In-Reply-To: <882700738.14181.1594819884049.JavaMail.zimbra@efficios.com> (Mathieu Desnoyers's message of "Wed, 15 Jul 2020 09:31:24 -0400 (EDT)")

* Mathieu Desnoyers:

> 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 ?

Yes, determining the thread pointer and access initial-exec TLS
variables is baked into the ABI.

> How would this allow early-rseq-adopter libraries to interact with
> glibc ?

Under all extension proposals I've seen so far, early adopters are
essentially incompatible with glibc rseq registration.  I don't think
you can have it both ways.

Thanks,
Florian


  reply	other threads:[~2020-07-15 13:42 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
2020-07-15 13:42                   ` Florian Weimer [this message]
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

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=87mu4028uk.fsf@oldenburg2.str.redhat.com \
    --to=fweimer@redhat.com \
    --cc=boqun.feng@gmail.com \
    --cc=carlos@redhat.com \
    --cc=christian.brauner@ubuntu.com \
    --cc=hpa@zytor.com \
    --cc=linux-api@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mathieu.desnoyers@efficios.com \
    --cc=paulmck@linux.ibm.com \
    --cc=peterz@infradead.org \
    --cc=pjt@google.com \
    --cc=tglx@linutronix.de \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.