Re: [PATCH 1/1] ACPI: resource: Fix memory resource type union access
From: Rafael J. Wysocki
Date: Mon Dec 09 2024 - 15:32:04 EST
On Mon, Dec 2, 2024 at 11:06 AM Ilpo Järvinen
<ilpo.jarvinen@xxxxxxxxxxxxxxx> wrote:
>
> In acpi_decode_space() addr->info.mem.caching is checked on main level
> for any resource type but addr->info.mem is part of union and thus
> valid only if the resource type is memory range.
>
> Move the check inside the preceeding switch/case to only execute it
> when the union is of correct type.
>
> Fixes: fcb29bbcd540 ("ACPI: Add prefetch decoding to the address space parser")
> Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@xxxxxxxxxxxxxxx>
> ---
>
> I only came across this while reading code around these parts (not
> because of investigating some issue).
>
> drivers/acpi/resource.c | 6 +++---
> 1 file changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/acpi/resource.c b/drivers/acpi/resource.c
> index 7fe842dae1ec..821867de43be 100644
> --- a/drivers/acpi/resource.c
> +++ b/drivers/acpi/resource.c
> @@ -250,6 +250,9 @@ static bool acpi_decode_space(struct resource_win *win,
> switch (addr->resource_type) {
> case ACPI_MEMORY_RANGE:
> acpi_dev_memresource_flags(res, len, wp);
> +
> + if (addr->info.mem.caching == ACPI_PREFETCHABLE_MEMORY)
> + res->flags |= IORESOURCE_PREFETCH;
> break;
> case ACPI_IO_RANGE:
> acpi_dev_ioresource_flags(res, len, iodec,
> @@ -265,9 +268,6 @@ static bool acpi_decode_space(struct resource_win *win,
> if (addr->producer_consumer == ACPI_PRODUCER)
> res->flags |= IORESOURCE_WINDOW;
>
> - if (addr->info.mem.caching == ACPI_PREFETCHABLE_MEMORY)
> - res->flags |= IORESOURCE_PREFETCH;
> -
> return !(res->flags & IORESOURCE_DISABLED);
> }
>
> --
Applied as 6.13-rc material, thanks!