[PATCH master] ARM: kasan: reserve shadow memory region

[PATCH master] ARM: kasan: reserve shadow memory region

[Ahmad Fatoum]

We did not have any protection in place to ensure that KASAN shadow memory
isn't overwritten during boot. Add that now to avoid strange effects
during debugging.

Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
---
 arch/arm/cpu/start.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/arch/arm/cpu/start.c b/arch/arm/cpu/start.c
index 15f5b2937227..9f4cdfe67fbf 100644
--- a/arch/arm/cpu/start.c
+++ b/arch/arm/cpu/start.c
@@ -133,6 +133,10 @@ static int barebox_memory_areas_init(void)
 		request_sdram_region("board data", (unsigned long)barebox_boarddata,
 				     barebox_boarddata_size);
 
+	if (IS_ENABLED(CONFIG_KASAN))
+		request_sdram_region("kasan shadow", kasan_shadow_base,
+				     mem_malloc_start() - kasan_shadow_base);
+
 	return 0;
 }
 device_initcall(barebox_memory_areas_init);
-- 
2.39.2

Re: [PATCH master] ARM: kasan: reserve shadow memory region

[Sascha Hauer]

On Wed, Jan 03, 2024 at 11:13:08AM +0100, Ahmad Fatoum wrote:
> We did not have any protection in place to ensure that KASAN shadow memory
> isn't overwritten during boot. Add that now to avoid strange effects
> during debugging.
> 
> Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
> ---
>  arch/arm/cpu/start.c | 4 ++++
>  1 file changed, 4 insertions(+)

Applied, thanks

Sascha

> 
> diff --git a/arch/arm/cpu/start.c b/arch/arm/cpu/start.c
> index 15f5b2937227..9f4cdfe67fbf 100644
> --- a/arch/arm/cpu/start.c
> +++ b/arch/arm/cpu/start.c
> @@ -133,6 +133,10 @@ static int barebox_memory_areas_init(void)
>  		request_sdram_region("board data", (unsigned long)barebox_boarddata,
>  				     barebox_boarddata_size);
>  
> +	if (IS_ENABLED(CONFIG_KASAN))
> +		request_sdram_region("kasan shadow", kasan_shadow_base,
> +				     mem_malloc_start() - kasan_shadow_base);
> +
>  	return 0;
>  }
>  device_initcall(barebox_memory_areas_init);
> -- 
> 2.39.2
> 
> 
> 

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Re: [PATCH master] ARM: kasan: reserve shadow memory region

[Sascha Hauer]

On Wed, Jan 03, 2024 at 11:13:08AM +0100, Ahmad Fatoum wrote:
> We did not have any protection in place to ensure that KASAN shadow memory
> isn't overwritten during boot. Add that now to avoid strange effects
> during debugging.
> 
> Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
> ---
>  arch/arm/cpu/start.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/arch/arm/cpu/start.c b/arch/arm/cpu/start.c
> index 15f5b2937227..9f4cdfe67fbf 100644
> --- a/arch/arm/cpu/start.c
> +++ b/arch/arm/cpu/start.c
> @@ -133,6 +133,10 @@ static int barebox_memory_areas_init(void)
>  		request_sdram_region("board data", (unsigned long)barebox_boarddata,
>  				     barebox_boarddata_size);
>  
> +	if (IS_ENABLED(CONFIG_KASAN))
> +		request_sdram_region("kasan shadow", kasan_shadow_base,
> +				     mem_malloc_start() - kasan_shadow_base);

This doesn't compile with CONFIG_KASAN disabled because
kasan_shadow_base is declared inside an #ifdef CONFIG_KASAN.

Could you send a v2?

Sascha

-- 
Pengutronix e.K.                           |                             |
Steuerwalder Str. 21                       | http://www.pengutronix.de/  |
31137 Hildesheim, Germany                  | Phone: +49-5121-206917-0    |
Amtsgericht Hildesheim, HRA 2686           | Fax:   +49-5121-206917-5555 |