Re: [PATCH] riscv: Protect kernel linear mapping only if CONFIG_STRICT_KERNEL_RWX is set

[Alex Ghiti]

Le 4/16/21 à 12:33 PM, Palmer Dabbelt a écrit :
> On Fri, 16 Apr 2021 03:47:19 PDT (-0700), alex@xxxxxxxx wrote:
> > Hi Anup,
> >
> > Le 4/16/21 à 6:41 AM, Anup Patel a écrit :
> > > On Thu, Apr 15, 2021 at 4:34 PM Alexandre Ghiti <alex@xxxxxxxx> wrote:
> > > > If CONFIG_STRICT_KERNEL_RWX is not set, we cannot set different 
> > > > permissions
> > > > to the kernel data and text sections, so make sure it is defined before
> > > > trying to protect the kernel linear mapping.
> > > >
> > > > Signed-off-by: Alexandre Ghiti <alex@xxxxxxxx>
> > >
> > > Maybe you should add "Fixes:" tag in commit tag ?
> >
> > Yes you're right I should have done that. Maybe Palmer will squash it as
> > it just entered for-next?
>
> Ya, I'll do it.  My testing box was just tied up last night for the rc8 
> PR, so I threw this on for-next to get the buildbots to take a look. 
> It's a bit too late to take something for this week, as I try to be 
> pretty conservative this late in the cycle.  There's another kprobes fix 
> on the list so if we end up with an rc8 I might send this along with 
> that, otherwise this'll just go onto for-next before the linear map 
> changes that exercise the bug.
>
> You're more than welcome to just dig up the fixes tag and reply, my 
> scripts pull all tags from replies (just like Revieweb-by).  Otherwise 
> I'll do it myself, most people don't really post Fixes tags that 
> accurately so I go through it for pretty much everything anyway.

Here it is:

Fixes: 4b67f48da707 ("riscv: Move kernel mapping outside of linear mapping")

Thanks,

> Thanks for sorting this out so quickly!
>
> > > Otherwise it looks good.
> > >
> > > Reviewed-by: Anup Patel <anup@xxxxxxxxxxxxxx>
> >
> > Thank you!
> >
> > Alex
> >
> > > Regards,
> > > Anup
> > >
> > > > ---
> > > >   arch/riscv/kernel/setup.c | 8 ++++----
> > > >   1 file changed, 4 insertions(+), 4 deletions(-)
> > > >
> > > > diff --git a/arch/riscv/kernel/setup.c b/arch/riscv/kernel/setup.c
> > > > index 626003bb5fca..ab394d173cd4 100644
> > > > --- a/arch/riscv/kernel/setup.c
> > > > +++ b/arch/riscv/kernel/setup.c
> > > > @@ -264,12 +264,12 @@ void __init setup_arch(char **cmdline_p)
> > > >
> > > >          sbi_init();
> > > >
> > > > -       if (IS_ENABLED(CONFIG_STRICT_KERNEL_RWX))
> > > > +       if (IS_ENABLED(CONFIG_STRICT_KERNEL_RWX)) {
> > > >                  protect_kernel_text_data();
> > > > -
> > > > -#if defined(CONFIG_64BIT) && defined(CONFIG_MMU)
> > > > -       protect_kernel_linear_mapping_text_rodata();
> > > > +#ifdef CONFIG_64BIT
> > > > +               protect_kernel_linear_mapping_text_rodata();
> > > >   #endif
> > > > +       }
> > > >
> > > >   #ifdef CONFIG_SWIOTLB
> > > >          swiotlb_init(1);
> > > > --
> > > > 2.20.1
> > >
> > > _______________________________________________
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> > > linux-riscv@xxxxxxxxxxxxxxxxxxx
> > > http://lists.infradead.org/mailman/listinfo/linux-riscv
>
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