linux-kernel - Re: [PATCH 1/2] riscv: Correct the initialized flow of FP register

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: <CAAhSdy0mOspKF7Z7H9MsbdrYYF3M_XGfm+F-dAt2wZSW_90PFg@mail.gmail.com>
Date:   Wed, 14 Aug 2019 09:21:57 +0530
From:   Anup Patel <anup@...infault.org>
To:     Vincent Chen <vincent.chen@...ive.com>
Cc:     Paul Walmsley <paul.walmsley@...ive.com>,
        Palmer Dabbelt <palmer@...ive.com>,
        Albert Ou <aou@...s.berkeley.edu>,
        linux-riscv <linux-riscv@...ts.infradead.org>,
        "linux-kernel@...r.kernel.org List" <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH 1/2] riscv: Correct the initialized flow of FP register

On Wed, Aug 14, 2019 at 7:15 AM Vincent Chen <vincent.chen@...ive.com> wrote:
>
> On Thu, Aug 8, 2019 at 11:50 PM Paul Walmsley <paul.walmsley@...ive.com> wrote:
> >
> > On Thu, 8 Aug 2019, Anup Patel wrote:
> >
> > > On Thu, Aug 8, 2019 at 1:30 PM Vincent Chen <vincent.chen@...ive.com> wrote:
> > > >
> > > > +static inline void fstate_off(struct task_struct *task,
> > > > +                              struct pt_regs *regs)
> > > > +{
> > > > +       regs->sstatus = (regs->sstatus & ~(SR_FS)) | SR_FS_OFF;
> > >
> > > The SR_FS_OFF is 0x0 so no need for ORing it.
> >
> > That one looks OK to me, since it makes it more obvious to humans what's
> > happening here - reviewers won't need to know that "off" is 0x0.  The
> > compiler should drop it internally, so it won't affect the generated
> > code.
> >
> Thanks for Paul's comment
> My thought is the same as Paul.
>
>
> > > Apart from above minor comment, looks good to me.
> > >
> > > Reviewed-by: Anup Patel <anup@...infault.org>
> >
> > Will add your Reviewed-by: tag - let us know if you want me to drop it or
> > caveat it.
> >
> >
> > - Paul
>
> Dear Anup,
> I suppose you can accept our thought about using the SR_FS_OFF flag
> because I didn't receive any reply from you.
> Thanks for your review and comments.

No problem, go ahead without dropping SR_FS_OFF flag.

You can include my Reviewed-by.

Regards,
Anup