efi_loader: correct OpenProtocol()

If a protocol is opened BY_DRIVER it cannot be opened by another agent
BY_DRIVER.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>

diff --git a/lib/efi_loader/efi_boottime.c b/lib/efi_loader/efi_boottime.c
index df57b3a984a337e0532aba4e87c4aaf9bda3a4e5..610eea463ebf37ba84e2258c480e675668afc895 100644 (file)
--- a/lib/efi_loader/efi_boottime.c
+++ b/lib/efi_loader/efi_boottime.c
@@ -2637,15 +2637,23 @@ static efi_status_t efi_protocol_open(
                        if ((attributes & EFI_OPEN_PROTOCOL_BY_DRIVER) &&
                            (item->info.attributes == attributes))
                                return EFI_ALREADY_STARTED;
+               } else {
+                       if (item->info.attributes &
+                           EFI_OPEN_PROTOCOL_BY_DRIVER)
+                               opened_by_driver = true;
                }
                if (item->info.attributes & EFI_OPEN_PROTOCOL_EXCLUSIVE)
                        opened_exclusive = true;
        }
 
        /* Only one controller can open the protocol exclusively */
-       if (opened_exclusive && attributes &
-           (EFI_OPEN_PROTOCOL_EXCLUSIVE | EFI_OPEN_PROTOCOL_BY_DRIVER))
-               return EFI_ACCESS_DENIED;
+       if (attributes & EFI_OPEN_PROTOCOL_EXCLUSIVE) {
+               if (opened_exclusive)
+                       return EFI_ACCESS_DENIED;
+       } else if (attributes & EFI_OPEN_PROTOCOL_BY_DRIVER) {
+               if (opened_exclusive || opened_by_driver)
+                       return EFI_ACCESS_DENIED;
+       }
 
        /* Prepare exclusive opening */
        if (attributes & EFI_OPEN_PROTOCOL_EXCLUSIVE) {