From: "Jason A. Donenfeld" <Jason@zx2c4.com>
To: Eric Biggers <ebiggers@kernel.org>
Cc: linux-kernel@vger.kernel.org, patches@lists.linux.dev,
linux-crypto@vger.kernel.org, x86@kernel.org,
Thomas Gleixner <tglx@linutronix.de>,
Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Adhemerval Zanella Netto <adhemerval.zanella@linaro.org>,
Carlos O'Donell <carlos@redhat.com>
Subject: Re: [PATCH v5 2/3] random: introduce generic vDSO getrandom() implementation
Date: Mon, 21 Nov 2022 04:22:54 +0100 [thread overview]
Message-ID: <Y3rvDg9H8lTL8ecU@zx2c4.com> (raw)
In-Reply-To: <Y3mGQyqPBTcoyPpS@zx2c4.com>
On Sun, Nov 20, 2022 at 02:43:31AM +0100, Jason A. Donenfeld wrote:
> On Sun, Nov 20, 2022 at 01:53:53AM +0100, Jason A. Donenfeld wrote:
> > shouldn't fork or something, but that seems disappointing. Or more state
> > could be allocated in the zeroing region, to hold a chacha state, so
> > another 64 bytes, which would be sort of unfortunate. Or something else?
> > I'd be interested to hear your impression of this quandary.
>
> Another 128 bytes, actually. And the current chacha in there isn't
> cleaning up its stack as one might hope. So maybe the cleanest solution
> would be to just bite the bullet and allocate another 128 bytes per
> state and make a mini chacha that operates over that? (And I guess hope
> it doesn't need to spill and such...)
I've got it implemented without using any stack now. Wasn't so bad. So
all of the additional concerns I added will be addressed in v+1.
Jason
next prev parent reply other threads:[~2022-11-21 3:23 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-11-19 12:09 [PATCH v5 0/3] implement getrandom() in vDSO Jason A. Donenfeld
2022-11-19 12:09 ` [PATCH v5 1/3] random: add vgetrandom_alloc() syscall Jason A. Donenfeld
2022-11-19 20:39 ` Eric Biggers
2022-11-19 23:59 ` Jason A. Donenfeld
2022-11-20 1:40 ` Eric Biggers
2022-11-20 1:45 ` Jason A. Donenfeld
2022-11-19 12:09 ` [PATCH v5 2/3] random: introduce generic vDSO getrandom() implementation Jason A. Donenfeld
2022-11-19 23:10 ` Eric Biggers
2022-11-20 0:53 ` Jason A. Donenfeld
2022-11-20 1:04 ` Jason A. Donenfeld
2022-11-21 3:23 ` Jason A. Donenfeld
2022-11-20 1:43 ` Jason A. Donenfeld
2022-11-21 3:22 ` Jason A. Donenfeld [this message]
2022-11-20 1:51 ` Eric Biggers
2022-11-19 12:09 ` [PATCH v5 3/3] x86: vdso: Wire up getrandom() vDSO implementation Jason A. Donenfeld
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