From: Segher Boessenkool <segher@kernel.crashing.org>
To: Christophe Leroy <christophe.leroy@c-s.fr>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>,
Paul Mackerras <paulus@samba.org>,
Michael Ellerman <mpe@ellerman.id.au>,
linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH v4 1/2] powerpc/32: add stack protector support
Date: Wed, 26 Sep 2018 14:16:16 -0500 [thread overview]
Message-ID: <20180926191615.GO23155@gate.crashing.org> (raw)
In-Reply-To: <d6c43ab708bf9ae1266c745fece457ed2da43d7c.1537961921.git.christophe.leroy@c-s.fr>
On Wed, Sep 26, 2018 at 11:40:38AM +0000, Christophe Leroy wrote:
> +static __always_inline void boot_init_stack_canary(void)
> +{
> + unsigned long canary;
> +
> + /* Try to get a semi random initial value. */
> + get_random_bytes(&canary, sizeof(canary));
> + canary ^= mftb();
> + canary ^= LINUX_VERSION_CODE;
> +
> + current->stack_canary = canary;
> +}
I still think you should wait until there is entropy available. You
haven't answered my questions about that (or I didn't see them): what
does the kernel do in other similar cases?
Looks great otherwise!
Segher
next prev parent reply other threads:[~2018-09-26 19:16 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-09-26 11:40 [PATCH v4 1/2] powerpc/32: add stack protector support Christophe Leroy
2018-09-26 11:40 ` [PATCH v4 2/2] powerpc/64: " Christophe Leroy
2018-09-26 19:16 ` Segher Boessenkool [this message]
2018-09-27 6:20 ` [PATCH v4 1/2] powerpc/32: " Christophe LEROY
2018-09-27 7:45 ` Segher Boessenkool
2018-09-27 11:51 ` Christophe LEROY
2018-09-28 12:56 ` Michael Ellerman
2018-09-28 16:26 ` Segher Boessenkool
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