Re: [PATCH] ACPI: PRM: Remove unnecessary strict handler address checks

[Rafael J. Wysocki]

On Sat, Feb 1, 2025 at 5:23 PM Ard Biesheuvel <ardb@xxxxxxxxxx> wrote:
>
> On Sun, 26 Jan 2025 at 03:08, Aubrey Li <aubrey.li@xxxxxxxxxxxxxxx> wrote:
> >
> > Commit 088984c8d54c ("ACPI: PRM: Find EFI_MEMORY_RUNTIME block for PRM
> > handler and context") added unnecessary strict handler address checks,
> > caused the PRM module to fail in translating memory error addresses.
> >
> > Both static data buffer address and acpi parameter buffer address may
> > be NULL if they are not needed, as described in section 4.1.2 PRM Handler
> > Information Structure of Platform Runtime Mechanism specification [1].
> >
> > Here are two examples from real hardware:
> >
> > ----PRMT.dsl----
> >
> > - staic data address is not used
> > [10Ch 0268   2]                     Revision : 0000
> > [10Eh 0270   2]                       Length : 002C
> > [110h 0272  16]                 Handler GUID : F6A58D47-E04F-4F5A-86B8-2A50D4AA109B
> > [120h 0288   8]              Handler address : 0000000065CE51F4
> > [128h 0296   8]           Satic Data Address : 0000000000000000
> > [130h 0304   8]       ACPI Parameter Address : 000000006522A718
> >
> > - ACPI parameter address is not used
> > [1B0h 0432   2]                     Revision : 0000
> > [1B2h 0434   2]                       Length : 002C
> > [1B4h 0436  16]                 Handler GUID : 657E8AE6-A8FC-4877-BB28-42E7DE1899A5
> > [1C4h 0452   8]              Handler address : 0000000065C567C8
> > [1CCh 0460   8]           Satic Data Address : 000000006113FB98
> > [1D4h 0468   8]       ACPI Parameter Address : 0000000000000000
> >
> > Fixes: 088984c8d54c ("ACPI: PRM: Find EFI_MEMORY_RUNTIME block for PRM handler and context")
> > Reported-and-tested-by: Shi Liu <aurelianliu@xxxxxxxxxxx>
> > Cc: All applicable <stable@xxxxxxxxxxxxxxx>
> > Signed-off-by: Aubrey Li <aubrey.li@xxxxxxxxxxxxxxx>
> > Link: https://uefi.org/sites/default/files/resources/Platform%20Runtime%20Mechanism%20-%20with%20legal%20notice.pdf # [1]
> > ---
> >  drivers/acpi/prmt.c | 4 +---
> >  1 file changed, 1 insertion(+), 3 deletions(-)
> >
>
> Acked-by: Ard Biesheuvel <ardb@xxxxxxxxxx>
>
> > diff --git a/drivers/acpi/prmt.c b/drivers/acpi/prmt.c
> > index 747f83f7114d..e549914a636c 100644
> > --- a/drivers/acpi/prmt.c
> > +++ b/drivers/acpi/prmt.c
> > @@ -287,9 +287,7 @@ static acpi_status acpi_platformrt_space_handler(u32 function,
> >                 if (!handler || !module)
> >                         goto invalid_guid;
> >
> > -               if (!handler->handler_addr ||
> > -                   !handler->static_data_buffer_addr ||
> > -                   !handler->acpi_param_buffer_addr) {
> > +               if (!handler->handler_addr) {
> >                         buffer->prm_status = PRM_HANDLER_ERROR;
> >                         return AE_OK;
> >                 }
> > --

Applied as 6.14-rc material, thanks!