Re: [PATCH] ACPICA: AML Parser: ignore control method status in module-level code

From: Rafael J. Wysocki
Date: Sun Jul 29 2018 - 06:25:31 EST


On Sat, Jul 28, 2018 at 11:05 PM, Erik Schmauss <erik.schmauss@xxxxxxxxx> wrote:
> Previous change in the AML parser code blindly set all non-successful
> dispatcher statuses to AE_OK. This approach is incorrect because
> successful control method invocations from module-level return
> AE_CTRL_TRANSFER. Overwriting AE_OK to this status causes the AML
> parser to think that there was no return value from the control
> method invocation.
>
> fixes: 73c2a01c52b6 (ACPICA: AML Parser: ignore dispatcher error status during table load)
>
> Reported-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
> Tested-by: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
> Tested-by: Oleksandr Natalenko <oleksandr@xxxxxxxxxxxxxx>
> Signed-off-by: Erik Schmauss <erik.schmauss@xxxxxxxxx>
> ---
> drivers/acpi/acpica/psloop.c | 19 ++++++++++++-------
> 1 file changed, 12 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/acpi/acpica/psloop.c b/drivers/acpi/acpica/psloop.c
> index ee840be150b5..44f35ab3347d 100644
> --- a/drivers/acpi/acpica/psloop.c
> +++ b/drivers/acpi/acpica/psloop.c
> @@ -709,15 +709,20 @@ acpi_status acpi_ps_parse_loop(struct acpi_walk_state *walk_state)
> } else
> if ((walk_state->
> parse_flags & ACPI_PARSE_MODULE_LEVEL)
> + && status != AE_CTRL_TRANSFER
> && ACPI_FAILURE(status)) {
> /*
> - * ACPI_PARSE_MODULE_LEVEL means that we are loading a table by
> - * executing it as a control method. However, if we encounter
> - * an error while loading the table, we need to keep trying to
> - * load the table rather than aborting the table load. Set the
> - * status to AE_OK to proceed with the table load. If we get a
> - * failure at this point, it means that the dispatcher got an
> - * error while processing Op (most likely an AML operand error.
> + * ACPI_PARSE_MODULE_LEVEL flag means that we are currently
> + * loading a table by executing it as a control method.
> + * However, if we encounter an error while loading the table,
> + * we need to keep trying to load the table rather than
> + * aborting the table load (setting the status to AE_OK
> + * continues the table load). If we get a failure at this
> + * point, it means that the dispatcher got an error while
> + * processing Op (most likely an AML operand error) or a
> + * control method was called from module level and the
> + * dispatcher returned AE_CTRL_TRANSFER. In the latter case,
> + * leave the status alone, there's nothing wrong with it.
> */
> status = AE_OK;
> }
> --

Applied, thanks!