From: Catalin Marinas <catalin.marinas@arm.com>
To: Will Deacon <will@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>,
Steve Capper <steve.capper@arm.com>,
Andrey Konovalov <andreyknvl@google.com>,
Geert Uytterhoeven <geert@linux-m68k.org>, Qian Cai <cai@lca.pw>,
linux-arm-kernel@lists.infradead.org
Subject: Re: [PATCH 1/8] arm64: memory: Fix virt_addr_valid() using __is_lm_address()
Date: Wed, 14 Aug 2019 10:19:42 +0100 [thread overview]
Message-ID: <20190814091942.GA50688@arrakis.emea.arm.com> (raw)
In-Reply-To: <20190813170149.26037-2-will@kernel.org>
On Tue, Aug 13, 2019 at 06:01:42PM +0100, Will Deacon wrote:
> diff --git a/arch/arm64/include/asm/memory.h b/arch/arm64/include/asm/memory.h
> index afaf512c0e1b..442ab861cab8 100644
> --- a/arch/arm64/include/asm/memory.h
> +++ b/arch/arm64/include/asm/memory.h
> @@ -244,9 +244,9 @@ static inline const void *__tag_set(const void *addr, u8 tag)
> /*
> * The linear kernel range starts in the middle of the virtual adddress
> * space. Testing the top bit for the start of the region is a
> - * sufficient check.
> + * sufficient check and avoids having to worry about the tag.
> */
> -#define __is_lm_address(addr) (!((addr) & BIT(vabits_actual - 1)))
> +#define __is_lm_address(addr) (!(((u64)addr) & BIT(vabits_actual - 1)))
>
> #define __lm_to_phys(addr) (((addr) + physvirt_offset))
> #define __kimg_to_phys(addr) ((addr) - kimage_voffset)
> @@ -326,13 +326,13 @@ static inline void *phys_to_virt(phys_addr_t x)
>
> #define virt_to_page(vaddr) ((struct page *)((__virt_to_pgoff(vaddr)) + VMEMMAP_START))
> #endif
> -#endif
>
> -#define _virt_addr_is_linear(kaddr) \
> - (__tag_reset((u64)(kaddr)) >= PAGE_OFFSET)
> +#define virt_addr_valid(addr) ({ \
> + __typeof__(addr) __addr = addr; \
> + __is_lm_address(__addr) && pfn_valid(virt_to_pfn(__addr)); \
> +})
There is a slight change of semantics here but I don't think it's an
issue currently. __is_lm_address() is true even for a user address, so
at least the first part of virt_addr_valid() now accepts such addresses.
The pfn would be wrong eventually because of the virt-to-phys offsetting
and pfn_valid() false but we rely on this rather than checking it's a
kernel address. Slight concern as this macro is called from drivers.
Should we keep the PAGE_OFFSET check as well?
--
Catalin
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next prev parent reply other threads:[~2019-08-14 9:19 UTC|newest]
Thread overview: 44+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-13 17:01 [PATCH 0/8] Fix issues with 52-bit kernel virtual addressing Will Deacon
2019-08-13 17:01 ` [PATCH 1/8] arm64: memory: Fix virt_addr_valid() using __is_lm_address() Will Deacon
2019-08-13 18:09 ` Ard Biesheuvel
2019-08-13 19:11 ` Steve Capper
2019-08-13 19:25 ` Ard Biesheuvel
2019-08-13 20:34 ` Steve Capper
2019-08-14 15:17 ` Ard Biesheuvel
2019-08-14 8:32 ` Will Deacon
2019-08-13 18:53 ` Steve Capper
2019-08-14 9:19 ` Catalin Marinas [this message]
2019-08-14 9:48 ` Will Deacon
2019-08-14 10:40 ` Catalin Marinas
2019-08-14 12:02 ` Will Deacon
2019-08-13 17:01 ` [PATCH 2/8] arm64: memory: Ensure address tag is masked in conversion macros Will Deacon
2019-08-13 18:54 ` Steve Capper
2019-08-14 9:23 ` Catalin Marinas
2019-08-13 17:01 ` [PATCH 3/8] arm64: memory: Rewrite default page_to_virt()/virt_to_page() Will Deacon
2019-08-13 18:54 ` Steve Capper
2019-08-14 9:30 ` Catalin Marinas
2019-08-14 9:41 ` Will Deacon
2019-08-14 10:56 ` Mark Rutland
2019-08-14 11:17 ` Will Deacon
2019-08-14 11:26 ` Mark Rutland
2019-08-13 17:01 ` [PATCH 4/8] arm64: memory: Simplify virt_to_page() implementation Will Deacon
2019-08-13 18:55 ` Steve Capper
2019-08-14 9:32 ` Catalin Marinas
2019-08-13 17:01 ` [PATCH 5/8] arm64: memory: Simplify _VA_START and _PAGE_OFFSET definitions Will Deacon
2019-08-13 18:55 ` Steve Capper
2019-08-14 9:33 ` Catalin Marinas
2019-08-14 11:23 ` Mark Rutland
2019-08-14 12:00 ` Will Deacon
2019-08-14 13:18 ` Mark Rutland
2019-08-13 17:01 ` [PATCH 6/8] arm64: memory: Implement __tag_set() as common function Will Deacon
2019-08-13 18:56 ` Steve Capper
2019-08-14 9:34 ` Catalin Marinas
2019-08-13 17:01 ` [PATCH 7/8] arm64: memory: Add comments to end of non-trivial #ifdef blocks Will Deacon
2019-08-13 18:57 ` Steve Capper
2019-08-14 9:35 ` Catalin Marinas
2019-08-13 17:01 ` [PATCH 8/8] arm64: memory: Cosmetic cleanups Will Deacon
2019-08-13 18:57 ` Steve Capper
2019-08-14 9:35 ` Catalin Marinas
2019-08-13 18:53 ` [PATCH 0/8] Fix issues with 52-bit kernel virtual addressing Steve Capper
2019-08-14 8:01 ` Geert Uytterhoeven
2019-08-14 11:29 ` Mark Rutland
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