2021-03-08 16:12:55

by Andrey Konovalov

Subject: [PATCH] arm64: kasan: fix page_alloc tagging with DEBUG_VIRTUAL

When CONFIG_DEBUG_VIRTUAL is enabled, the default page_to_virt() macro
implementation from include/linux/mm.h is used. That definition doesn't
account for KASAN tags, which leads to no tags on page_alloc allocations.

Provide an arm64-specific definition for page_to_virt() when
CONFIG_DEBUG_VIRTUAL is enabled that takes care of KASAN tags.

Fixes: 2813b9c02962 ("kasan, mm, arm64: tag non slab memory allocated via pagealloc")
Cc: <[email protected]>
Signed-off-by: Andrey Konovalov <[email protected]>
---
arch/arm64/include/asm/memory.h | 5 +++++
1 file changed, 5 insertions(+)

diff --git a/arch/arm64/include/asm/memory.h b/arch/arm64/include/asm/memory.h
index c759faf7a1ff..0aabc3be9a75 100644
--- a/arch/arm64/include/asm/memory.h
+++ b/arch/arm64/include/asm/memory.h
@@ -328,6 +328,11 @@ static inline void *phys_to_virt(phys_addr_t x)
#define ARCH_PFN_OFFSET ((unsigned long)PHYS_PFN_OFFSET)

#if !defined(CONFIG_SPARSEMEM_VMEMMAP) || defined(CONFIG_DEBUG_VIRTUAL)
+#define page_to_virt(x) ({ \
+ __typeof__(x) __page = x; \
+ void *__addr = __va(page_to_phys(__page)); \
+ (void *)__tag_set((const void *)__addr, page_kasan_tag(__page));\
+})
#define virt_to_page(x) pfn_to_page(virt_to_pfn(x))
#else
#define page_to_virt(x) ({ \
--
2.30.1.766.gb4fecdf3b7-goog

2021-03-08 18:46:15

by Catalin Marinas

Subject: Re: [PATCH] arm64: kasan: fix page_alloc tagging with DEBUG_VIRTUAL

On Mon, Mar 08, 2021 at 05:10:23PM +0100, Andrey Konovalov wrote:
> When CONFIG_DEBUG_VIRTUAL is enabled, the default page_to_virt() macro
> implementation from include/linux/mm.h is used. That definition doesn't
> account for KASAN tags, which leads to no tags on page_alloc allocations.
>
> Provide an arm64-specific definition for page_to_virt() when
> CONFIG_DEBUG_VIRTUAL is enabled that takes care of KASAN tags.
>
> Fixes: 2813b9c02962 ("kasan, mm, arm64: tag non slab memory allocated via pagealloc")
> Cc: <[email protected]>
> Signed-off-by: Andrey Konovalov <[email protected]>
> ---
> arch/arm64/include/asm/memory.h | 5 +++++
> 1 file changed, 5 insertions(+)
>
> diff --git a/arch/arm64/include/asm/memory.h b/arch/arm64/include/asm/memory.h
> index c759faf7a1ff..0aabc3be9a75 100644
> --- a/arch/arm64/include/asm/memory.h
> +++ b/arch/arm64/include/asm/memory.h
> @@ -328,6 +328,11 @@ static inline void *phys_to_virt(phys_addr_t x)
> #define ARCH_PFN_OFFSET ((unsigned long)PHYS_PFN_OFFSET)
>
> #if !defined(CONFIG_SPARSEMEM_VMEMMAP) || defined(CONFIG_DEBUG_VIRTUAL)
> +#define page_to_virt(x) ({ \
> + __typeof__(x) __page = x; \
> + void *__addr = __va(page_to_phys(__page)); \
> + (void *)__tag_set((const void *)__addr, page_kasan_tag(__page));\
> +})
> #define virt_to_page(x) pfn_to_page(virt_to_pfn(x))

Reviewed-by: Catalin Marinas <[email protected]>

2021-03-09 15:40:23

by Will Deacon

Subject: Re: [PATCH] arm64: kasan: fix page_alloc tagging with DEBUG_VIRTUAL

On Mon, 8 Mar 2021 17:10:23 +0100, Andrey Konovalov wrote:
> When CONFIG_DEBUG_VIRTUAL is enabled, the default page_to_virt() macro
> implementation from include/linux/mm.h is used. That definition doesn't
> account for KASAN tags, which leads to no tags on page_alloc allocations.
>
> Provide an arm64-specific definition for page_to_virt() when
> CONFIG_DEBUG_VIRTUAL is enabled that takes care of KASAN tags.

Applied to arm64 (for-next/fixes), thanks!

[1/1] arm64: kasan: fix page_alloc tagging with DEBUG_VIRTUAL
https://git.kernel.org/arm64/c/86c83365ab76

Cheers,
--
Will

https://fixes.arm64.dev
https://next.arm64.dev
https://will.arm64.dev