linux-kernel - Re: [PATCH resend] MIPS: Allow FPU emulator to use non-stack area.

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: <CA+=Sn1nR2ugXUf=V9F9O6VLAP1d6WhBDioZzu0G05-8z6KMMuA@mail.gmail.com>
Date:	Mon, 6 Oct 2014 17:11:38 -0700
From:	Andrew Pinski <pinskia@...il.com>
To:	Rich Felker <dalias@...c.org>
Cc:	David Daney <ddaney@...iumnetworks.com>,
	Andy Lutomirski <luto@...capital.net>,
	David Daney <ddaney.cavm@...il.com>,
	GNU C Library <libc-alpha@...rceware.org>,
	LKML <linux-kernel@...r.kernel.org>, linux-mips@...ux-mips.org,
	David Daney <david.daney@...ium.com>
Subject: Re: [PATCH resend] MIPS: Allow FPU emulator to use non-stack area.

On Mon, Oct 6, 2014 at 5:05 PM, Rich Felker <dalias@...c.org> wrote:
> On Mon, Oct 06, 2014 at 04:48:52PM -0700, David Daney wrote:
>> On 10/06/2014 04:38 PM, Andy Lutomirski wrote:
>> >On 10/06/2014 02:58 PM, Rich Felker wrote:
>> >>On Mon, Oct 06, 2014 at 02:45:29PM -0700, David Daney wrote:
>> [...]
>> >>This is a huge ill-designed mess.
>> >
>> >Amen.
>> >
>> >Can the kernel not just emulate the instructions directly?
>>
>> In theory it could, but since there can be implementation defined
>> instructions, there is no way to achieve full instruction set
>> coverage for all possible machines.
>
> Is the issue really implementation-defined instructions with delay
> slots? If so it sounds like a made-up issue. They're not going to
> occur in real binaries. Certainly a compiler is not going to generate
> implementation-defined instructions, and if you're writing the asm by
> hand, you just don't put floating point instructions in the delay
> slot.

It is not the instruction with delay slot but rather the instruction
in the delay slot itself.

Thanks,
Andrew
--
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/