linux-kernel - Re: [PATCH RFC] random: introduce get_random_bytes_busy_wait

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <1380110810.3165.140.camel@edumazet-glaptop>
Date:	Wed, 25 Sep 2013 05:06:50 -0700
From:	Eric Dumazet <eric.dumazet@...il.com>
To:	Hannes Frederic Sowa <hannes@...essinduktion.org>
Cc:	Tom Herbert <therbert@...gle.com>, davem@...emloft.net,
	netdev@...r.kernel.org, jesse.brandeburg@...el.com, tytso@....edu,
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH RFC] random: introduce
 get_random_bytes_busy_wait_initialized

On Wed, 2013-09-25 at 11:00 +0200, Hannes Frederic Sowa wrote:

>  /*
> + * Busy loop until the nonblocking_pool is intialized and return
> + * random data in buf of size nbytes.
> + *
> + * This is used by the network stack to defer the extraction of
> + * entropy from the nonblocking_pool until the pool is initialized.
> + *
> + * We need to busy loop here, because we could be called from an
> + * atomic section.
> + */
> +void get_random_bytes_busy_wait_initialized(void *buf, int nbytes)
> +{
> +	while (!nonblocking_pool.initialized)
> +		cpu_relax();
> +	get_random_bytes(buf, nbytes);
> +}

No idea if this can work if called from IRQ context.

How is nonblocking_poll initialized if host has a single cpu ?



--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/