From: Amos Kong <akong@redhat.com>
To: Fengguang Wu <fengguang.wu@intel.com>
Cc: Avi Kivity <avi@redhat.com>,
kernel-janitors@vger.kernel.org, kvm@vger.kernel.org
Subject: Re: [kvm:next 1/1] arch/x86/kvm/emulate.c:232 writeback_registers() error: buffer overflow 'ctxt->_r
Date: Wed, 12 Sep 2012 05:58:22 +0000 [thread overview]
Message-ID: <5050247E.3070905@redhat.com> (raw)
In-Reply-To: <20120911143136.GA5736@localhost>
On 11/09/12 22:31, Fengguang Wu wrote:
> Hi Avi,
>
> In the kvm/next branch, sparse warns about
>
> arch/x86/kvm/emulate.c:232 writeback_registers() error: buffer overflow 'ctxt->_regs' 9 <= 15
>
> This is because the array definition is ctxt._regs[NR_VCPU_REGS] where
> NR_VCPU_REGS=9 for i386 and 17 for x86_64.
>
> It could be fixed by changing the hard coded 16 to (NR_VCPU_REGS-1).
Hi Fengguang,
You replaced 16 to NR_VCPU_REGS in your patch, not (NR_VCPU_REGS-1).
I guess it's a mistake in your commitlog, right?
> And I wonder whether you actually want NR_VCPU_REGS here?
>
> Thanks,
> Fengguang
> ---
> --- linux-next.orig/arch/x86/kvm/emulate.c 2012-09-11 20:14:00.537475301 +0800
> +++ linux-next/arch/x86/kvm/emulate.c 2012-09-11 22:21:57.569227558 +0800
> @@ -228,7 +228,7 @@ static void writeback_registers(struct x
> {
> unsigned reg;
>
> - for_each_set_bit(reg, (ulong *)&ctxt->regs_dirty, 16)
> + for_each_set_bit(reg, (ulong *)&ctxt->regs_dirty, NR_VCPU_REGS)
> ctxt->ops->write_gpr(ctxt, reg, ctxt->_regs[reg]);
> }
>
--
Amos.
next prev parent reply other threads:[~2012-09-12 5:58 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-09-11 14:31 [kvm:next 1/1] arch/x86/kvm/emulate.c:232 writeback_registers() error: buffer overflow 'ctxt->_regs' Fengguang Wu
2012-09-12 5:58 ` Amos Kong [this message]
2012-09-12 6:07 ` [kvm:next 1/1] arch/x86/kvm/emulate.c:232 writeback_registers() error: buffer overflow 'ctxt->_r Fengguang Wu
2012-09-12 7:37 ` Avi Kivity
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