[PATCH v3 5/5] lib: utils/irqchip: plic: Ensure no out-of-bound access in context save/restore helpers

[Samuel Holland]

On 12/11/22 00:54, Bin Meng wrote:
> Currently the context save/restore helpers writes/reads the provided
> array using an index whose maximum value is determined by PLIC, which
> potentially may disagree with the caller to these helpers.
> 
> Add a parameter to ask the caller to provide the size limit of the
> array to ensure no out-of-bound access happens.
> 
> Signed-off-by: Bin Meng <bmeng at tinylab.org>
> 
> ---
> 
> Changes in v3:
> - move the size limit check to plic_context_save/restore
> 
> Changes in v2:
> - new patch: lib: utils/irqchip: plic: Ensure no out-of-bound access in context save/restore helpers
> 
>  include/sbi_utils/irqchip/fdt_irqchip_plic.h |  5 +++--
>  include/sbi_utils/irqchip/plic.h             |  4 ++--
>  lib/utils/irqchip/fdt_irqchip_plic.c         |  9 +++++----
>  lib/utils/irqchip/plic.c                     | 14 ++++++++++----
>  platform/generic/allwinner/sun20i-d1.c       |  5 +++--
>  5 files changed, 23 insertions(+), 14 deletions(-)
> 
[...]
> diff --git a/platform/generic/allwinner/sun20i-d1.c b/platform/generic/allwinner/sun20i-d1.c
> index 1f27575..1da9e5b 100644
> --- a/platform/generic/allwinner/sun20i-d1.c
> +++ b/platform/generic/allwinner/sun20i-d1.c
> @@ -78,7 +78,7 @@ static u32 plic_threshold;
>  
>  static void sun20i_d1_plic_save(void)
>  {
> -	fdt_plic_context_save(true, plic_sie, &plic_threshold);
> +	fdt_plic_context_save(true, plic_sie, &plic_threshold, PLIC_IE_WORDS);

While the actual value ends up being the same, you should update the
definition of PLIC_IE_WORDS to use the same formula used elsewhere.

Regards,
Samuel

>  	fdt_plic_priority_save(plic_priority, PLIC_SOURCES);
>  }
>  
> @@ -86,7 +86,8 @@ static void sun20i_d1_plic_restore(void)
>  {
>  	thead_plic_restore();
>  	fdt_plic_priority_restore(plic_priority, PLIC_SOURCES);
> -	fdt_plic_context_restore(true, plic_sie, plic_threshold);
> +	fdt_plic_context_restore(true, plic_sie, plic_threshold,
> +				 PLIC_IE_WORDS);
>  }
>  
>  /*