[PATCH 1/1] ACPI: resource: Fix memory resource type union access

[PATCH 1/1] ACPI: resource: Fix memory resource type union access

[Ilpo Järvinen]

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@linux.intel.com>
---

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);
 }
 
-- 
2.39.5

Re: [PATCH 1/1] ACPI: resource: Fix memory resource type union access

[Rafael J. Wysocki]

On Mon, Dec 2, 2024 at 11:06 AM Ilpo Järvinen
<ilpo.jarvinen@linux.intel.com> 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@linux.intel.com>
> ---
>
> 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!