MIME-Version: 1.0
In-Reply-To: <21a22ace-fbc3-4f97-a277-9cdf4f2253eb@email.android.com>
References: <tip-kicdm89kzw9lldryb1br9od0@git.kernel.org>
	<CAMzpN2jx4H4p8fQr-WHxVyCHhWi0iO3WZZKyxYD7Dfa7pWkEgg@mail.gmail.com>
	<CA+55aFwzvSiAGYfFb2R3JeVvh8_PQuOKJDrYP5C_3VQz2zhnBw@mail.gmail.com>
	<CAMzpN2jj3dwQG7qC__8zLPhkg_ER6n4CcNxa5eg7okRN+k_VUA@mail.gmail.com>
	<CA+55aFxr_dz3vhko1FPXhZd0ZNeGveX0oSLqUo_wyiVbxatLQw@mail.gmail.com>
	<CAMzpN2jn69_E7UEP6OHBbc4r7UuJbsW50WA25YhXuQs5sHFxQQ@mail.gmail.com>
	<6f5f98f2-aa96-433f-9ee8-5ba216624957@email.android.com>
	<20140412193541.GA30697@pd.tnic>
	<21a22ace-fbc3-4f97-a277-9cdf4f2253eb@email.android.com>
Date: Sat, 12 Apr 2014 14:53:56 -0700
Message-ID: <CA+55aFy8s7cfaAXJ7WyJ4aMpBnsWGt2mA1=pduQwK+ofkvbzVg@mail.gmail.com>
Subject: Re: [tip:x86/urgent] x86-64, modify_ldt: Ban 16-bit segments on
 64-bit kernels
From: Linus Torvalds <torvalds@linux-foundation.org>
To: "H. Peter Anvin" <hpa@zytor.com>
Cc: Borislav Petkov <bp@alien8.de>, Brian Gerst <brgerst@gmail.com>,
        Ingo Molnar <mingo@kernel.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        Thomas Gleixner <tglx@linutronix.de>, stable <stable@vger.kernel.org>,
        "H. Peter Anvin" <hpa@linux.intel.com>
Content-Type: text/plain; charset=UTF-8
Sender: linux-kernel-owner@vger.kernel.org

On Sat, Apr 12, 2014 at 12:44 PM, H. Peter Anvin <hpa@zytor.com> wrote:
> Run a 32-bit VM.  The 32-bit kernel does this right.

I really don't think that's the answer.

If people really run these 16-bit programs, we need to allow it.
Clearly it used to work.

Just make the unconditional "don't allow 16-bit segments" be a sysconf entry.

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