Re: [PATCH] riscv: mm: implement pgprot_nx

From: Jisheng Zhang <jszhang@kernel.org>
To: Paul Walmsley <paul.walmsley@sifive.com>,
	Palmer Dabbelt <palmer@dabbelt.com>,
	Albert Ou <aou@eecs.berkeley.edu>
Cc: linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org
Subject: Re: [PATCH] riscv: mm: implement pgprot_nx
Date: Mon, 15 Jan 2024 17:42:26 +0800	[thread overview]
Message-ID: <ZaT+Ai+Lbzx1qBYr@xhacker> (raw)
In-Reply-To: <20231121160637.3856-1-jszhang@kernel.org>

On Wed, Nov 22, 2023 at 12:06:37AM +0800, Jisheng Zhang wrote:
> commit cca98e9f8b5e ("mm: enforce that vmap can't map pages
> executable") enforces the W^X protection by not allowing remapping
> existing pages as executable. Add riscv bits so that riscv can benefit
> the same protection.

And this simple patch to enforce W^X protection is also missed ;)

Thanks in advance
> 
> Signed-off-by: Jisheng Zhang <jszhang@kernel.org>
> ---
>  arch/riscv/include/asm/pgtable.h | 6 ++++++
>  1 file changed, 6 insertions(+)
> 
> diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h
> index 294044429e8e..4fc6ee5226fb 100644
> --- a/arch/riscv/include/asm/pgtable.h
> +++ b/arch/riscv/include/asm/pgtable.h
> @@ -608,6 +608,12 @@ static inline int ptep_clear_flush_young(struct vm_area_struct *vma,
>  	return ptep_test_and_clear_young(vma, address, ptep);
>  }
>  
> +#define pgprot_nx pgprot_nx
> +static inline pgprot_t pgprot_nx(pgprot_t _prot)
> +{
> +	return __pgprot(pgprot_val(_prot) & ~_PAGE_EXEC);
> +}
> +
>  #define pgprot_noncached pgprot_noncached
>  static inline pgprot_t pgprot_noncached(pgprot_t _prot)
>  {
> -- 
> 2.42.0
> 
> 
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