Groups | Search | Server Info | Keyboard shortcuts | Login | Register [http] [https] [nntp] [nntps]


Groups > linux.kernel > #1692472

Re: [RFC v6 27/62] powerpc: helper to validate key-access permissions of a pte

From "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
Newsgroups linux.kernel
Subject Re: [RFC v6 27/62] powerpc: helper to validate key-access permissions of a pte
Date 2017-07-20 08:50 +0200
Message-ID <u5drz-3uU-7@gated-at.bofh.it> (permalink)
References <u3ISR-1St-3@gated-at.bofh.it> <u3J2y-2aY-25@gated-at.bofh.it>
Organization linux.* mail to news gateway

Show all headers | View raw


Ram Pai <linuxram@us.ibm.com> writes:

> helper function that checks if the read/write/execute is allowed
> on the pte.
>
> Signed-off-by: Ram Pai <linuxram@us.ibm.com>
> ---
>  arch/powerpc/include/asm/book3s/64/pgtable.h |    4 +++
>  arch/powerpc/include/asm/pkeys.h             |   12 +++++++++
>  arch/powerpc/mm/pkeys.c                      |   33 ++++++++++++++++++++++++++
>  3 files changed, 49 insertions(+), 0 deletions(-)
>
> diff --git a/arch/powerpc/include/asm/book3s/64/pgtable.h b/arch/powerpc/include/asm/book3s/64/pgtable.h
> index 30d7f55..0056e58 100644
> --- a/arch/powerpc/include/asm/book3s/64/pgtable.h
> +++ b/arch/powerpc/include/asm/book3s/64/pgtable.h
> @@ -472,6 +472,10 @@ static inline void write_uamor(u64 value)
>  	mtspr(SPRN_UAMOR, value);
>  }
>
> +#ifdef CONFIG_PPC64_MEMORY_PROTECTION_KEYS
> +extern bool arch_pte_access_permitted(u64 pte, bool write, bool execute);
> +#endif /* CONFIG_PPC64_MEMORY_PROTECTION_KEYS */
> +
>  #define __HAVE_ARCH_PTEP_GET_AND_CLEAR
>  static inline pte_t ptep_get_and_clear(struct mm_struct *mm,
>  				       unsigned long addr, pte_t *ptep)
> diff --git a/arch/powerpc/include/asm/pkeys.h b/arch/powerpc/include/asm/pkeys.h
> index bbb5d85..7a9aade 100644
> --- a/arch/powerpc/include/asm/pkeys.h
> +++ b/arch/powerpc/include/asm/pkeys.h
> @@ -53,6 +53,18 @@ static inline u64 pte_to_hpte_pkey_bits(u64 pteflags)
>  		((pteflags & H_PAGE_PKEY_BIT4) ? HPTE_R_KEY_BIT4 : 0x0UL));
>  }
>
> +static inline u16 pte_to_pkey_bits(u64 pteflags)
> +{
> +	if (!pkey_inited)
> +		return 0x0UL;

Do we really need that above check ? We should always find it
peky_inited to be set. 

> +
> +	return (((pteflags & H_PAGE_PKEY_BIT0) ? 0x10 : 0x0UL) |
> +		((pteflags & H_PAGE_PKEY_BIT1) ? 0x8 : 0x0UL) |
> +		((pteflags & H_PAGE_PKEY_BIT2) ? 0x4 : 0x0UL) |
> +		((pteflags & H_PAGE_PKEY_BIT3) ? 0x2 : 0x0UL) |
> +		((pteflags & H_PAGE_PKEY_BIT4) ? 0x1 : 0x0UL));
> +}
> +


-aneesh

Back to linux.kernel | Previous | Next — Next in thread | Find similar | Unroll thread


Thread

Re: [RFC v6 27/62] powerpc: helper to validate key-access permissions of a pte "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com> - 2017-07-20 08:50 +0200
  Re: [RFC v6 27/62] powerpc: helper to validate key-access  permissions of a pte Ram Pai <linuxram@us.ibm.com> - 2017-07-21 00:20 +0200
    Re: [RFC v6 27/62] powerpc: helper to validate key-access permissions of a pte "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com> - 2017-07-21 09:00 +0200
      Re: [RFC v6 27/62] powerpc: helper to validate key-access  permissions of a pte Ram Pai <linuxram@us.ibm.com> - 2017-07-21 18:50 +0200

csiph-web