Messages in this thread | | | Date | Thu, 8 Feb 2024 19:22:52 +0100 | Subject | Re: [PATCH] platform/x86: wmi: Make input buffer madatory when evaulating methods | From | Armin Wolf <> |
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Am 08.02.24 um 03:41 schrieb Kuppuswamy Sathyanarayanan:
> On 2/7/24 12:20 PM, Armin Wolf wrote: >> The ACPI-WMI specification declares that a WMxx control method takes >> 3 arguments: instance, method id and argument buffer. This is also >> the case even when the underlying WMI method does not have any >> input arguments. > It would be better if you include specification version and section > title for reference.
The ACPI-WMI specification is not part of the ACPI specification. It consists of a single whitepaper published by Microsoft:
https://github.com/microsoft/Windows-driver-samples/blob/main/wmi/wmiacpi/wmi-acpi.htm
The section describing the ACPI control methods is called "ACPI Control Method Naming Conventions and Functionality for Windows 2000 Instrumentation".
I do not thing that mentioning this in the commit message would be of any use.
>> So if a WMI driver evaluates a WMI method without passing an input >> buffer, ACPICA will log a warning complaining that the third argument >> is missing. > I assume it is a compile warning. Can you copy the warning message?
Its not a compiler warning.
The ACPI control method is being evaluated at runtime, so the warning message will also be generated at runtime (when interpreting the AML bytecode).
Thanks, Armin Wolf
>> Prevent this by checking that a input buffer was passed, and return >> an error if this was not the case. >> >> Tested on a Asus PRIME B650-Plus. >> >> Signed-off-by: Armin Wolf <W_Armin@gmx.de> >> --- > > With above fixed, > > Reviewed-by: Kuppuswamy Sathyanarayanan <sathyanarayanan.kuppuswamy@linux.intel.com> > >> drivers/platform/x86/wmi.c | 21 ++++++++++----------- >> 1 file changed, 10 insertions(+), 11 deletions(-) >> >> diff --git a/drivers/platform/x86/wmi.c b/drivers/platform/x86/wmi.c >> index 63906fdd0abf..f9e23d491dd9 100644 >> --- a/drivers/platform/x86/wmi.c >> +++ b/drivers/platform/x86/wmi.c >> @@ -296,7 +296,7 @@ EXPORT_SYMBOL_GPL(wmidev_instance_count); >> * @guid_string: 36 char string of the form fa50ff2b-f2e8-45de-83fa-65417f2f49ba >> * @instance: Instance index >> * @method_id: Method ID to call >> - * @in: Buffer containing input for the method call >> + * @in: Mandatory buffer containing input for the method call >> * @out: Empty buffer to return the method results >> * >> * Call an ACPI-WMI method, the caller must free @out. >> @@ -326,7 +326,7 @@ EXPORT_SYMBOL_GPL(wmi_evaluate_method); >> * @wdev: A wmi bus device from a driver >> * @instance: Instance index >> * @method_id: Method ID to call >> - * @in: Buffer containing input for the method call >> + * @in: Mandatory buffer containing input for the method call >> * @out: Empty buffer to return the method results >> * >> * Call an ACPI-WMI method, the caller must free @out. >> @@ -347,26 +347,25 @@ acpi_status wmidev_evaluate_method(struct wmi_device *wdev, u8 instance, u32 met >> block = &wblock->gblock; >> handle = wblock->acpi_device->handle; >> >> + if (!in) >> + return AE_BAD_DATA; >> + >> if (!(block->flags & ACPI_WMI_METHOD)) >> return AE_BAD_DATA; >> >> if (block->instance_count <= instance) >> return AE_BAD_PARAMETER; >> >> - input.count = 2; >> + input.count = 3; >> input.pointer = params; >> + >> params[0].type = ACPI_TYPE_INTEGER; >> params[0].integer.value = instance; >> params[1].type = ACPI_TYPE_INTEGER; >> params[1].integer.value = method_id; >> - >> - if (in) { >> - input.count = 3; >> - >> - params[2].type = get_param_acpi_type(wblock); >> - params[2].buffer.length = in->length; >> - params[2].buffer.pointer = in->pointer; >> - } >> + params[2].type = get_param_acpi_type(wblock); >> + params[2].buffer.length = in->length; >> + params[2].buffer.pointer = in->pointer; >> >> get_acpi_method_name(wblock, 'M', method); >> >> -- >> 2.39.2 >> >>
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