[PATCH] ACPI: PRM: Optimize the judgment logic for the PRM handler_address

[PATCH] ACPI: PRM: Optimize the judgment logic for the PRM handler_address

[shangsong]

From: Shang song (Lenovo) <shangsong2@lenovo.com>

If the handler_address or mapped VA is NULL, the related buffer
address and VA can be ignored.

Signed-off-by: Shang song <shangsong2@lenovo.com>
---
 drivers/acpi/prmt.c | 19 ++++++++++++++++---
 1 file changed, 16 insertions(+), 3 deletions(-)

diff --git a/drivers/acpi/prmt.c b/drivers/acpi/prmt.c
index be033bbb126a..3a501fcd78df 100644
--- a/drivers/acpi/prmt.c
+++ b/drivers/acpi/prmt.c
@@ -150,15 +150,28 @@ acpi_parse_prmt(union acpi_subtable_headers *header, const unsigned long end)
 		th = &tm->handlers[cur_handler];
 
 		guid_copy(&th->guid, (guid_t *)handler_info->handler_guid);
+
+		/*
+		 * Print a error message if handler_address is NULL, the parse of VA also
+		 * can be skipped.
+		 */
+		if (unlikely(!handler_info->handler_address)) {
+			pr_err("Skipping handler with NULL address for GUID: %pUL",
+					(guid_t *)handler_info->handler_guid);
+			continue;
+		}
+
 		th->handler_addr =
 			(void *)efi_pa_va_lookup(&th->guid, handler_info->handler_address);
 		/*
-		 * Print a warning message if handler_addr is zero which is not expected to
-		 * ever happen.
+		 * Print a warning message and skip the parse of VA if handler_addr is zero
+		 * which is not expected to ever happen.
 		 */
-		if (unlikely(!th->handler_addr))
+		if (unlikely(!th->handler_addr)) {
 			pr_warn("Failed to find VA of handler for GUID: %pUL, PA: 0x%llx",
 				&th->guid, handler_info->handler_address);
+			continue;
+		}
 
 		th->static_data_buffer_addr =
 			efi_pa_va_lookup(&th->guid, handler_info->static_data_buffer_address);
-- 
2.43.7

Re: [PATCH] ACPI: PRM: Optimize the judgment logic for the PRM handler_address

[Rafael J. Wysocki]

On Tue, Aug 19, 2025 at 4:28 AM shangsong <shangsong2@foxmail.com> wrote:
>
> From: Shang song (Lenovo) <shangsong2@lenovo.com>
>
> If the handler_address or mapped VA is NULL, the related buffer
> address and VA can be ignored.
>
> Signed-off-by: Shang song <shangsong2@lenovo.com>
> ---
>  drivers/acpi/prmt.c | 19 ++++++++++++++++---
>  1 file changed, 16 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/acpi/prmt.c b/drivers/acpi/prmt.c
> index be033bbb126a..3a501fcd78df 100644
> --- a/drivers/acpi/prmt.c
> +++ b/drivers/acpi/prmt.c
> @@ -150,15 +150,28 @@ acpi_parse_prmt(union acpi_subtable_headers *header, const unsigned long end)
>                 th = &tm->handlers[cur_handler];
>
>                 guid_copy(&th->guid, (guid_t *)handler_info->handler_guid);
> +
> +               /*
> +                * Print a error message if handler_address is NULL, the parse of VA also
> +                * can be skipped.
> +                */
> +               if (unlikely(!handler_info->handler_address)) {
> +                       pr_err("Skipping handler with NULL address for GUID: %pUL",
> +                                       (guid_t *)handler_info->handler_guid);

pr_info(), please.

> +                       continue;
> +               }
> +
>                 th->handler_addr =
>                         (void *)efi_pa_va_lookup(&th->guid, handler_info->handler_address);
>                 /*
> -                * Print a warning message if handler_addr is zero which is not expected to
> -                * ever happen.
> +                * Print a warning message and skip the parse of VA if handler_addr is zero
> +                * which is not expected to ever happen.
>                  */
> -               if (unlikely(!th->handler_addr))
> +               if (unlikely(!th->handler_addr)) {
>                         pr_warn("Failed to find VA of handler for GUID: %pUL, PA: 0x%llx",
>                                 &th->guid, handler_info->handler_address);
> +                       continue;
> +               }
>
>                 th->static_data_buffer_addr =
>                         efi_pa_va_lookup(&th->guid, handler_info->static_data_buffer_address);
> --