From: "Jason A. Donenfeld" <Jason@zx2c4.com>
To: Adhemerval Zanella Netto <adhemerval.zanella@linaro.org>
Cc: libc-alpha@sourceware.org, "Florian Weimer" <fweimer@redhat.com>,
"Cristian Rodríguez" <crrodriguez@opensuse.org>,
"Paul Eggert" <eggert@cs.ucla.edu>,
"Mark Harris" <mark.hsj@gmail.com>,
"Eric Biggers" <ebiggers@kernel.org>,
linux-crypto@vger.kernel.org
Subject: Re: [PATCH v4] arc4random: simplify design for better safety
Date: Tue, 26 Jul 2022 20:36:45 +0200 [thread overview]
Message-ID: <YuA0PcpBdWU5MS9s@zx2c4.com> (raw)
In-Reply-To: <45ef8ca0-12ca-4853-98a0-9f52dfca8c57@linaro.org>
Hi Adhemerval,
On Tue, Jul 26, 2022 at 01:20:11PM -0300, Adhemerval Zanella Netto wrote:
> > + {
> > + atomic_store_relaxed (&have_getrandom, false);
>
> I still think there is no much gain in this optimization, the syscall will
> most likely be present and it is one less static data. Also, we avoid to
> use __ASSUME_GETRANDOM on generic code (all __ASSUME usage within
> sysdeps and/or nptl).
Oh! *That's* what you were talking about before. Sorry I didn't catch
your meaning the first time through.
Okay so you're alright having +1 syscall overhead on old systems, so
that new systems can have a byte less of static data. I don't hold any
opinions either way there and will defer to your expertise, so I'll get
rid of this part on v5.
> > + __ppoll_infinity_nocancel;
> > __sigtimedwait;
> > # functions used by nscd
> > __netlink_assert_response;
>
> There is no need to export on GLIBC_PRIVATE, since it is not currently usage
> libc.so. Just define is a hidden (attribute_hidden).
> Use attribute_hidden here and remove it from sysdeps/unix/sysv/linux/Versions.
>> Maybe just add an inline wrapper on sysdeps/unix/sysv/linux/not-cancel.h,
> as for __getrandom_nocancel:
> It avoids a lot of boilerplate code to add the internal symbol.
Okay I'll skip all the symbol stuff and just do the static inline like
getrandom has. Thanks for the suggestion; that's a lot simpler.
> Also update the hurd sysdeps/mach/hurd/not-cancel.h with a wrapper to
> __poll (since it does not really support pthread cancellation).
Ack.
Thanks for the comments. v5 coming up shortly.
Jason
next prev parent reply other threads:[~2022-07-26 18:36 UTC|newest]
Thread overview: 81+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <YtwgTySJyky0OcgG@zx2c4.com>
2022-07-23 16:25 ` arc4random - are you sure we want these? Jason A. Donenfeld
2022-07-23 17:18 ` Paul Eggert
2022-07-24 23:55 ` Jason A. Donenfeld
2022-07-25 20:31 ` Paul Eggert
2022-07-23 17:39 ` Adhemerval Zanella Netto
2022-07-23 22:54 ` Jason A. Donenfeld
2022-07-25 15:33 ` Rich Felker
2022-07-25 15:59 ` Adhemerval Zanella Netto
2022-07-25 17:41 ` Rich Felker
2022-07-25 16:18 ` Sandy Harris
2022-07-25 16:40 ` Florian Weimer
2022-07-25 16:49 ` Adhemerval Zanella Netto
2022-07-25 16:51 ` Jason A. Donenfeld
2022-07-25 17:44 ` Rich Felker
2022-07-25 18:33 ` Cristian Rodríguez
2022-07-25 18:49 ` Rich Felker
2022-07-27 1:54 ` Theodore Ts'o
2022-07-27 2:16 ` Rich Felker
2022-07-27 2:45 ` Theodore Ts'o
2022-07-27 11:34 ` Adhemerval Zanella Netto
2022-07-27 12:32 ` Theodore Ts'o
2022-07-27 12:49 ` Florian Weimer
2022-07-27 20:15 ` Theodore Ts'o
2022-07-27 21:59 ` Rich Felker
2022-07-28 0:30 ` Theodore Ts'o
2022-07-28 0:39 ` Cristian Rodríguez
2022-07-27 15:39 ` Rich Felker
2022-07-23 19:04 ` Cristian Rodríguez
2022-07-23 22:59 ` Jason A. Donenfeld
2022-07-24 16:23 ` Cristian Rodríguez
2022-07-24 21:57 ` Jason A. Donenfeld
2022-07-25 10:14 ` Florian Weimer
2022-07-25 10:11 ` Florian Weimer
2022-07-25 11:04 ` Jason A. Donenfeld
2022-07-25 12:39 ` Florian Weimer
2022-07-25 13:43 ` Jason A. Donenfeld
2022-07-25 13:58 ` Cristian Rodríguez
2022-07-25 16:06 ` Rich Felker
2022-07-25 16:43 ` Florian Weimer
2022-07-26 14:27 ` Overwrittting AT_RANDOM after use (was Re: arc4random - are you sure we want these?) Yann Droneaud
2022-07-26 14:35 ` arc4random - are you sure we want these? Yann Droneaud
2022-07-25 13:25 ` Jeffrey Walton
2022-07-25 13:48 ` Jason A. Donenfeld
2022-07-25 14:56 ` Rich Felker
2022-07-25 22:57 ` [PATCH] arc4random: simplify design for better safety Jason A. Donenfeld
2022-07-25 23:11 ` Jason A. Donenfeld
2022-07-25 23:28 ` [PATCH v2] " Jason A. Donenfeld
2022-07-25 23:59 ` Eric Biggers
2022-07-26 10:26 ` Jason A. Donenfeld
2022-07-26 1:10 ` Mark Harris
2022-07-26 10:41 ` Jason A. Donenfeld
2022-07-26 11:06 ` Florian Weimer
2022-07-26 16:51 ` Mark Harris
2022-07-26 18:42 ` Jason A. Donenfeld
2022-07-26 19:18 ` Adhemerval Zanella Netto
2022-07-26 19:24 ` Jason A. Donenfeld
2022-07-26 9:55 ` Florian Weimer
2022-07-26 11:04 ` Jason A. Donenfeld
2022-07-26 11:07 ` [PATCH v3] " Jason A. Donenfeld
2022-07-26 11:11 ` Jason A. Donenfeld
2022-07-26 11:12 ` [PATCH v2] " Florian Weimer
2022-07-26 11:20 ` Jason A. Donenfeld
2022-07-26 11:35 ` Adhemerval Zanella Netto
2022-07-26 11:33 ` Adhemerval Zanella Netto
2022-07-26 11:54 ` Jason A. Donenfeld
2022-07-26 12:08 ` Jason A. Donenfeld
2022-07-26 12:20 ` Jason A. Donenfeld
2022-07-26 12:34 ` Adhemerval Zanella Netto
2022-07-26 12:47 ` Jason A. Donenfeld
2022-07-26 13:11 ` Adhemerval Zanella Netto
2022-07-26 13:30 ` [PATCH v4] " Jason A. Donenfeld
2022-07-26 15:21 ` Yann Droneaud
2022-07-26 16:20 ` Adhemerval Zanella Netto
2022-07-26 18:36 ` Jason A. Donenfeld [this message]
2022-07-26 19:08 ` [PATCH v5] " Jason A. Donenfeld
2022-07-26 19:58 ` [PATCH v6] " Jason A. Donenfeld
2022-07-26 20:17 ` Adhemerval Zanella Netto
2022-07-26 20:56 ` Adhemerval Zanella Netto
2022-07-28 10:29 ` Szabolcs Nagy
2022-07-28 10:36 ` Szabolcs Nagy
2022-07-28 11:01 ` Adhemerval Zanella
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