efi/efi_test: read RuntimeServicesSupported

Since the UEFI 2.8A specification the UEFI enabled firmware provides a
configuration table EFI_RT_PROPERTIES_TABLE which indicates which runtime
services are enabled. The EFI stub reads this table and saves the value of
the field RuntimeServicesSupported internally.

The Firmware Test Suite requires the value to determine if UEFI runtime
services are correctly implemented.

With this patch an IOCTL call is provided to read the value of the field
RuntimeServicesSupported, e.g.

#define EFI_RUNTIME_GET_SUPPORTED_MASK \
_IOR('p', 0x0C, unsigned int)
unsigned int mask;
fd = open("/dev/efi_test", O_RDWR);
ret = ioctl(fd, EFI_RUNTIME_GET_SUPPORTED_MASK, &mask);

Signed-off-by: Heinrich Schuchardt <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
Acked-by: Colin Ian King <[e-mail]>
Acked-by: Ivan Hu <[e-mail]>
Signed-off-by: Ard Biesheuvel <[e-mail]>

drivers/firmware/efi/test/efi_test.c

···
 	return rv;
 }
 
+static long efi_runtime_get_supported_mask(unsigned long arg)
+{
+	unsigned int __user *supported_mask;
+	int rv = 0;
+
+	supported_mask = (unsigned int *)arg;
+
+	if (put_user(efi.runtime_supported_mask, supported_mask))
+		rv = -EFAULT;
+
+	return rv;
+}
+
 static long efi_test_ioctl(struct file *file, unsigned int cmd,
 							unsigned long arg)
 {
···
 
 	case EFI_RUNTIME_RESET_SYSTEM:
 		return efi_runtime_reset_system(arg);
+
+	case EFI_RUNTIME_GET_SUPPORTED_MASK:
+		return efi_runtime_get_supported_mask(arg);
 	}
 
 	return -ENOTTY;

drivers/firmware/efi/test/efi_test.h

···
 #define EFI_RUNTIME_RESET_SYSTEM \
 	_IOW('p', 0x0B, struct efi_resetsystem)
 
+#define EFI_RUNTIME_GET_SUPPORTED_MASK \
+	_IOR('p', 0x0C, unsigned int)
+
 #endif /* _DRIVERS_FIRMWARE_EFI_TEST_H_ */