[RFC PATCH 2/3] efi/test: Don't bother pseudo-testing unused EFI services

[Ard Biesheuvel <ardb+git@xxxxxxxxxx>]

From: Ard Biesheuvel <ardb@xxxxxxxxxx>

The EFI test module covers the get/set wakeup time EFI runtime
services, as well as GetNextHighMonoCount(). In both cases, though, it
just mindlessly exercises the API, without any functional testing.

In case of the get/set wakeup time services, this would involve setting
the wakeup time, and subsequently checking whether the system actually
wakes up at the configured time, which is difficult for obvious reasons.

In case of GetNextHighMonoCount(), this would involve performing some
kind of verification that the returned number increases monotonically
across reboots.

Given that these APIs are not used in Linux to begin with, let's not
pretend that testing them in this manner has any value, and just drop
these tests entirely, so that we can drop the APIs themselves from the
Linux EFI runtime layer.

Signed-off-by: Ard Biesheuvel <ardb@xxxxxxxxxx>
---
 drivers/firmware/efi/test/efi_test.c | 108 +-------------------
 1 file changed, 2 insertions(+), 106 deletions(-)

diff --git a/drivers/firmware/efi/test/efi_test.c 
b/drivers/firmware/efi/test/efi_test.c
index 77b5f7ac3e20..bb2ace902346 100644
--- a/drivers/firmware/efi/test/efi_test.c
+++ b/drivers/firmware/efi/test/efi_test.c
@@ -333,77 +333,6 @@ static long efi_runtime_set_time(unsigned long arg)
        return status == EFI_SUCCESS ? 0 : -EINVAL;
 }
 
-static long efi_runtime_get_waketime(unsigned long arg)
-{
-       struct efi_getwakeuptime __user *getwakeuptime_user;
-       struct efi_getwakeuptime getwakeuptime;
-       efi_bool_t enabled, pending;
-       efi_status_t status;
-       efi_time_t efi_time;
-
-       getwakeuptime_user = (struct efi_getwakeuptime __user *)arg;
-       if (copy_from_user(&getwakeuptime, getwakeuptime_user,
-                               sizeof(getwakeuptime)))
-               return -EFAULT;
-
-       status = efi.get_wakeup_time(
-               getwakeuptime.enabled ? (efi_bool_t *)&enabled : NULL,
-               getwakeuptime.pending ? (efi_bool_t *)&pending : NULL,
-               getwakeuptime.time ? &efi_time : NULL);
-
-       if (put_user(status, getwakeuptime.status))
-               return -EFAULT;
-
-       if (status != EFI_SUCCESS)
-               return -EINVAL;
-
-       if (getwakeuptime.enabled && put_user(enabled,
-                                               getwakeuptime.enabled))
-               return -EFAULT;
-
-       if (getwakeuptime.pending && put_user(pending,
-                                               getwakeuptime.pending))
-               return -EFAULT;
-
-       if (getwakeuptime.time) {
-               if (copy_to_user(getwakeuptime.time, &efi_time,
-                               sizeof(efi_time_t)))
-                       return -EFAULT;
-       }
-
-       return 0;
-}
-
-static long efi_runtime_set_waketime(unsigned long arg)
-{
-       struct efi_setwakeuptime __user *setwakeuptime_user;
-       struct efi_setwakeuptime setwakeuptime;
-       efi_bool_t enabled;
-       efi_status_t status;
-       efi_time_t efi_time;
-
-       setwakeuptime_user = (struct efi_setwakeuptime __user *)arg;
-
-       if (copy_from_user(&setwakeuptime, setwakeuptime_user,
-                               sizeof(setwakeuptime)))
-               return -EFAULT;
-
-       enabled = setwakeuptime.enabled;
-       if (setwakeuptime.time) {
-               if (copy_from_user(&efi_time, setwakeuptime.time,
-                                       sizeof(efi_time_t)))
-                       return -EFAULT;
-
-               status = efi.set_wakeup_time(enabled, &efi_time);
-       } else
-               status = efi.set_wakeup_time(enabled, NULL);
-
-       if (put_user(status, setwakeuptime.status))
-               return -EFAULT;
-
-       return status == EFI_SUCCESS ? 0 : -EINVAL;
-}
-
 static long efi_runtime_get_nextvariablename(unsigned long arg)
 {
        struct efi_getnextvariablename __user *getnextvariablename_user;
@@ -505,37 +434,6 @@ static long efi_runtime_get_nextvariablename(unsigned long 
arg)
        return rv;
 }
 
-static long efi_runtime_get_nexthighmonocount(unsigned long arg)
-{
-       struct efi_getnexthighmonotoniccount __user *getnexthighmonocount_user;
-       struct efi_getnexthighmonotoniccount getnexthighmonocount;
-       efi_status_t status;
-       u32 count;
-
-       getnexthighmonocount_user = (struct
-                       efi_getnexthighmonotoniccount __user *)arg;
-
-       if (copy_from_user(&getnexthighmonocount,
-                          getnexthighmonocount_user,
-                          sizeof(getnexthighmonocount)))
-               return -EFAULT;
-
-       status = efi.get_next_high_mono_count(
-               getnexthighmonocount.high_count ? &count : NULL);
-
-       if (put_user(status, getnexthighmonocount.status))
-               return -EFAULT;
-
-       if (status != EFI_SUCCESS)
-               return -EINVAL;
-
-       if (getnexthighmonocount.high_count &&
-           put_user(count, getnexthighmonocount.high_count))
-               return -EFAULT;
-
-       return 0;
-}
-
 static long efi_runtime_reset_system(unsigned long arg)
 {
        struct efi_resetsystem __user *resetsystem_user;
@@ -697,16 +595,14 @@ static long efi_test_ioctl(struct file *file, unsigned 
int cmd,
                return efi_runtime_set_time(arg);
 
        case EFI_RUNTIME_GET_WAKETIME:
-               return efi_runtime_get_waketime(arg);
-
        case EFI_RUNTIME_SET_WAKETIME:
-               return efi_runtime_set_waketime(arg);
+               return -EINVAL;
 
        case EFI_RUNTIME_GET_NEXTVARIABLENAME:
                return efi_runtime_get_nextvariablename(arg);
 
        case EFI_RUNTIME_GET_NEXTHIGHMONOTONICCOUNT:
-               return efi_runtime_get_nexthighmonocount(arg);
+               return -EINVAL;
 
        case EFI_RUNTIME_QUERY_VARIABLEINFO:
                return efi_runtime_query_variableinfo(arg);
-- 
2.50.0.727.gbf7dc18ff4-goog