linux-kernel - Re: [PATCH v8 3/3] x86, mce: Add __mcsafe

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]

Date:	Mon, 11 Jan 2016 16:37:35 -0800
From:	Andy Lutomirski <luto@...capital.net>
To:	"Luck, Tony" <tony.luck@...el.com>
Cc:	linux-nvdimm <linux-nvdimm@...1.01.org>,
	Dan Williams <dan.j.williams@...el.com>,
	Borislav Petkov <bp@...en8.de>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	Andrew Morton <akpm@...ux-foundation.org>,
	Robert <elliott@....com>, Ingo Molnar <mingo@...nel.org>,
	"linux-mm@...ck.org" <linux-mm@...ck.org>, X86 ML <x86@...nel.org>
Subject: Re: [PATCH v8 3/3] x86, mce: Add __mcsafe_copy()

On Mon, Jan 11, 2016 at 4:26 PM, Luck, Tony <tony.luck@...el.com> wrote:
> On Fri, Jan 08, 2016 at 05:49:30PM -0800, Andy Lutomirski wrote:
>> Also, what's the sfence for?  You don't seem to be using any
>> non-temporal operations.
>
> So I deleted the "sfence" and now I just have a comment
> at the 100: label.
>
> 37:
>         shl $6,%ecx
>         lea -48(%ecx,%edx),%edx
>         jmp 100f
> 38:
>         shl $6,%ecx
>         lea -56(%ecx,%edx),%edx
>         jmp 100f
> 39:
>         lea (%rdx,%rcx,8),%rdx
>         jmp 100f
> 40:
>         mov %ecx,%edx
> 100:
>         /* %rax set the fault number in fixup_exception() */
>         ret
>
> Should I just change all the "jmp 100f" into "ret"?  There
> aren't any tools that will be confused that the function
> has 10 returns, are there?
>

Given that gcc does that too, it should be fine.

--Andy\