linux-kernel - Re: [PATCH] riscv: Discard vector state on syscalls

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]

Date:   Mon, 26 Jun 2023 17:46:57 +0200
From:   Björn Töpel <bjorn@...nel.org>
To:     Vineet Gupta <vineetg@...osinc.com>,
        Paul Walmsley <paul.walmsley@...ive.com>,
        Palmer Dabbelt <palmer@...belt.com>,
        Albert Ou <aou@...s.berkeley.edu>,
        linux-riscv@...ts.infradead.org
Cc:     Björn Töpel <bjorn@...osinc.com>,
        linux-kernel@...r.kernel.org, linux@...osinc.com,
        Palmer Dabbelt <palmer@...osinc.com>,
        Rémi Denis-Courmont 
        <remi@...lab.net>, Darius Rad <darius@...espec.com>,
        Andy Chiu <andy.chiu@...ive.com>
Subject: Re: [PATCH] riscv: Discard vector state on syscalls

Vineet Gupta <vineetg@...osinc.com> writes:

> On 6/22/23 10:36, Björn Töpel wrote:
>> From: Björn Töpel <bjorn@...osinc.com>
>>
>> The RISC-V vector specification states:
>>    Executing a system call causes all caller-saved vector registers
>>    (v0-v31, vl, vtype) and vstart to become unspecified.
>
> So the only use case of saving/restoring V regs in __switch_to is an 
> interrupt induced task switch ?

Yes!