From: Anshuman Khandual <anshuman.khandual@arm.com>
To: Will Deacon <will@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>,
David Hildenbrand <david@redhat.com>,
catalin.marinas@arm.com, linux-kernel@vger.kernel.org,
Steven Price <steven.price@arm.com>,
Andrew Morton <akpm@linux-foundation.org>,
Robin Murphy <robin.murphy@arm.com>,
Ard Biesheuvel <ardb@kernel.org>,
linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH] arm64/mm: Validate hotplug range before creating linear mapping
Date: Tue, 6 Oct 2020 12:05:51 +0530 [thread overview]
Message-ID: <262f2fd8-2e0c-4eaf-d4ff-f72728049f52@arm.com> (raw)
In-Reply-To: <f44d34df-8a21-712c-138d-f7f633b0eb6c@arm.com>
On 09/30/2020 01:32 PM, Anshuman Khandual wrote:
> But if __is_lm_address() checks against the effective linear range instead
> i.e [_PAGE_OFFSET(vabits_actual)..(PAGE_END - 1)], it can be used for hot
> plug physical range check there after. Perhaps something like this, though
> not tested properly.
>
> diff --git a/arch/arm64/include/asm/memory.h b/arch/arm64/include/asm/memory.h
> index afa722504bfd..6da046b479d4 100644
> --- a/arch/arm64/include/asm/memory.h
> +++ b/arch/arm64/include/asm/memory.h
> @@ -238,7 +238,10 @@ static inline const void *__tag_set(const void *addr, u8 tag)
> * space. Testing the top bit for the start of the region is a
> * sufficient check and avoids having to worry about the tag.
> */
> -#define __is_lm_address(addr) (!(((u64)addr) & BIT(vabits_actual - 1)))
> +static inline bool __is_lm_address(unsigned long addr)
> +{
> + return ((addr >= _PAGE_OFFSET(vabits_actual)) && (addr <= (PAGE_END - 1)));
> +}
>
> #define __lm_to_phys(addr) (((addr) + physvirt_offset))
> #define __kimg_to_phys(addr) ((addr) - kimage_voffset)
> diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c
> index d59ffabb9c84..5750370a7e8c 100644
> --- a/arch/arm64/mm/mmu.c
> +++ b/arch/arm64/mm/mmu.c
> @@ -1451,8 +1451,7 @@ static bool inside_linear_region(u64 start, u64 size)
> * address range mapped by the linear map, the start address should
> * be calculated using vabits_actual.
> */
> - return ((start >= __pa(_PAGE_OFFSET(vabits_actual)))
> - && ((start + size) <= __pa(PAGE_END - 1)));
> + return __is_lm_address(__va(start)) && __is_lm_address(__va(start + size));
> }
>
> int arch_add_memory(int nid, u64 start, u64 size,
Will/Ard,
Any thoughts about this ? __is_lm_address() now checks for a range instead
of a bit. This will be compatible later on, even if linear mapping range
changes from current lower half scheme.
- Anshuman
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next prev parent reply other threads:[~2020-10-06 6:37 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-09-17 8:46 [PATCH] arm64/mm: Validate hotplug range before creating linear mapping Anshuman Khandual
2020-09-28 20:35 ` Will Deacon
2020-09-29 8:04 ` Anshuman Khandual
2020-09-29 15:22 ` Will Deacon
2020-09-30 8:02 ` Anshuman Khandual
2020-09-30 11:01 ` Ard Biesheuvel
2020-10-06 6:28 ` Anshuman Khandual
2020-10-06 6:35 ` Anshuman Khandual [this message]
2020-10-12 7:29 ` Ard Biesheuvel
2020-10-14 5:06 ` Anshuman Khandual
2020-10-14 6:37 ` Ard Biesheuvel
2020-10-06 15:34 ` David Hildenbrand
2020-10-07 2:50 ` Anshuman Khandual
2020-10-07 8:39 ` David Hildenbrand
2020-10-19 11:23 ` Anshuman Khandual
2020-10-19 14:58 ` David Hildenbrand
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