From: Andi Kleen <andi@firstfloor.org>
To: Erik Bosman <erik@minemu.org>
Cc: linux-kernel@vger.kernel.org
Subject: Re: [PATCH 2/4] x86: SROP mitigation: implement signal canaries
Date: Thu, 15 May 2014 14:31:40 -0700 [thread overview]
Message-ID: <87vbt6rao3.fsf@tassilo.jf.intel.com> (raw)
In-Reply-To: <20140515211004.GA9575@pizzadoos.com> (Erik Bosman's message of "Thu, 15 May 2014 23:10:04 +0200")
Erik Bosman <erik@minemu.org> writes:
>
> diff --git a/arch/x86/ia32/ia32_signal.c b/arch/x86/ia32/ia32_signal.c
> index 2206757..1a9285a 100644
> --- a/arch/x86/ia32/ia32_signal.c
> +++ b/arch/x86/ia32/ia32_signal.c
> @@ -212,9 +212,18 @@ asmlinkage long sys32_sigreturn(void)
> struct sigframe_ia32 __user *frame = (struct sigframe_ia32 __user *)(regs->sp-8);
> sigset_t set;
> unsigned int ax;
> +#ifdef CONFIG_SIGNAL_CANARY
> + u32 canary;
> +#endif
Don't you completely break the ABI here? I'm sure there are programs out
there who hard code the offset into the FP state.
I think you either need to put it at the total end or somewhere
currently unused
Besides that I would remove the CONFIG_* once it works and just do it
unconditionally.
-Andi
--
ak@linux.intel.com -- Speaking for myself only
next prev parent reply other threads:[~2014-05-15 21:31 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-05-15 21:10 [PATCH 2/4] x86: SROP mitigation: implement signal canaries Erik Bosman
2014-05-15 21:31 ` Andi Kleen [this message]
2014-05-15 22:32 ` Erik Bosman
2014-05-16 16:03 ` Andi Kleen
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