linux-kernel - Re: [PATCH v3 3/3] x86: Zap TOP_OF_KERNEL_STACK_PADDING on x86

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] [day] [month] [year] [list]

Message-ID: <8925f277-a173-47c4-95e3-ed6234a45043@zytor.com>
Date: Sun, 11 May 2025 23:13:44 -0700
From: Xin Li <xin@...or.com>
To: "H. Peter Anvin" <hpa@...or.com>, Brian Gerst <brgerst@...il.com>
Cc: linux-kernel@...r.kernel.org, luto@...nel.org, tglx@...utronix.de,
        mingo@...nel.org, bp@...en8.de, dave.hansen@...ux.intel.com,
        x86@...nel.org, peterz@...radead.org
Subject: Re: [PATCH v3 3/3] x86: Zap TOP_OF_KERNEL_STACK_PADDING on x86_64

On 3/21/2025 1:14 AM, H. Peter Anvin wrote:
> On March 20, 2025 10:47:25 PM PDT, Xin Li <xin@...or.com> wrote:
>> On 3/19/2025 12:17 PM, Brian Gerst wrote:
>>> I'm not sure it's worth fully removing TOP_OF_KERNEL_STACK_PADDING for
>>> 64-bit if it results in needing separate definitions of
>>> task_top_of_stack().  Leaving it at zero is fine.  The other changes
>>> are fine though.
>>
>> Let's leave it to x86 maintainers ;-)
>>
>> But to me, TOP_OF_KERNEL_STACK_PADDING no longer makes sense on 64-bit,
>> and it makes it simpler to remove it.  On the other side, 32-bit is to
>> be zapped...
>>
>> Thanks!
>>     Xin
>>
> 
> For what it's worth, it was there as 0 before the FRED changes, so ...
> 

Okay, I will drop this patch and send the patch set as v4.

Thanks!
     Xin