linux-kernel - Re: [PATCH v3 07/21] x86/fpu/xstate: Introduce helpers to manage dynamic xstate buffers

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: <D7000856-4F6F-4BCB-A72E-4624A4A81C31@intel.com>
Date:   Wed, 3 Feb 2021 04:10:11 +0000
From:   "Bae, Chang Seok" <chang.seok.bae@...el.com>
To:     Borislav Petkov <bp@...e.de>
CC:     Andy Lutomirski <luto@...nel.org>,
        "tglx@...utronix.de" <tglx@...utronix.de>,
        "mingo@...nel.org" <mingo@...nel.org>,
        "x86@...nel.org" <x86@...nel.org>,
        "Brown, Len" <len.brown@...el.com>,
        "Hansen, Dave" <dave.hansen@...el.com>,
        "Liu, Jing2" <jing2.liu@...el.com>,
        "Shankar, Ravi V" <ravi.v.shankar@...el.com>,
        "linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH v3 07/21] x86/fpu/xstate: Introduce helpers to manage
 dynamic xstate buffers

On Jan 26, 2021, at 12:17, Borislav Petkov <bp@...e.de> wrote:
> On Wed, Dec 23, 2020 at 07:57:03AM -0800, Chang S. Bae wrote:
>> 
>> +int alloc_xstate_buffer(struct fpu *fpu, u64 mask)

<snip>

>> +	if (newsz > fpu_kernel_xstate_max_size) {
>> +		pr_warn_once("x86/fpu: xstate buffer too large (%u > %u bytes)\n",
>> +			     newsz, fpu_kernel_xstate_max_size);
>> +		XSTATE_WARN_ON(1);
>> +		return 0;
> 
> return 0?!? On an error?!?

With more discussions, I now think it is too much to check like this. This
function (merely) allocates the requested size. So, going to remove it.

Thanks,
Chang