efi_open_protocol has to keep track of opened protocols.
OpenProtocol enters the agent and controller handle information into this list.
A unit test is supplied with a subsequent patch.
Signed-off-by: Heinrich Schuchardt xypron.glpk@gmx.de --- v3 no change v2 no change --- lib/efi_loader/efi_boottime.c | 107 ++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 103 insertions(+), 4 deletions(-)
diff --git a/lib/efi_loader/efi_boottime.c b/lib/efi_loader/efi_boottime.c index f5ec2a8866..bb80c6066a 100644 --- a/lib/efi_loader/efi_boottime.c +++ b/lib/efi_loader/efi_boottime.c @@ -2100,6 +2100,101 @@ static void EFIAPI efi_set_mem(void *buffer, size_t size, uint8_t value) EFI_EXIT(EFI_SUCCESS); }
+/* + * Open protocol interface on a handle. + * + * @handler handler of a protocol + * @protocol_interface interface implementing the protocol + * @agent_handle handle of the driver + * @controller_handle handle of the controller + * @attributes attributes indicating how to open the protocol + * @return status code + */ +static efi_status_t efi_protocol_open( + struct efi_handler *handler, + void **protocol_interface, void *agent_handle, + void *controller_handle, uint32_t attributes) +{ + struct efi_open_protocol_info_item *item; + struct efi_open_protocol_info_entry *match = NULL; + bool opened_by_driver = false; + bool opened_exclusive = false; + + /* If there is no agent, only return the interface */ + if (!agent_handle) + goto out; + + /* For TEST_PROTOCOL ignore interface attribute */ + if (attributes != EFI_OPEN_PROTOCOL_TEST_PROTOCOL) + *protocol_interface = NULL; + + /* + * Check if the protocol is already opened by a driver with the same + * attributes or opened exclusively + */ + list_for_each_entry(item, &handler->open_infos, link) { + if (item->info.agent_handle == agent_handle) { + if ((attributes & EFI_OPEN_PROTOCOL_BY_DRIVER) && + (item->info.attributes == attributes)) + return EFI_ALREADY_STARTED; + } + 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; + + /* Prepare exclusive opening */ + if (attributes & EFI_OPEN_PROTOCOL_EXCLUSIVE) { + /* Try to disconnect controllers */ + list_for_each_entry(item, &handler->open_infos, link) { + if (item->info.attributes == + EFI_OPEN_PROTOCOL_BY_DRIVER) + EFI_CALL(efi_disconnect_controller( + item->info.controller_handle, + item->info.agent_handle, + NULL)); + } + opened_by_driver = false; + /* Check if all controllers are disconnected */ + list_for_each_entry(item, &handler->open_infos, link) { + if (item->info.attributes & EFI_OPEN_PROTOCOL_BY_DRIVER) + opened_by_driver = true; + } + /* Only one controller can be conncected */ + if (opened_by_driver) + return EFI_ACCESS_DENIED; + } + + /* Find existing entry */ + list_for_each_entry(item, &handler->open_infos, link) { + if (item->info.agent_handle == agent_handle && + item->info.controller_handle == controller_handle) + match = &item->info; + } + /* None found, create one */ + if (!match) { + match = efi_create_open_info(handler); + if (!match) + return EFI_OUT_OF_RESOURCES; + } + + match->agent_handle = agent_handle; + match->controller_handle = controller_handle; + match->attributes = attributes; + match->open_count++; + +out: + /* For TEST_PROTOCOL ignore interface attribute. */ + if (attributes != EFI_OPEN_PROTOCOL_TEST_PROTOCOL) + *protocol_interface = handler->protocol_interface; + + return EFI_SUCCESS; +} + /* * Open protocol interface on a handle. * @@ -2141,12 +2236,16 @@ static efi_status_t EFIAPI efi_open_protocol( case EFI_OPEN_PROTOCOL_BY_CHILD_CONTROLLER: if (controller_handle == handle) goto out; + /* fall-through */ case EFI_OPEN_PROTOCOL_BY_DRIVER: case EFI_OPEN_PROTOCOL_BY_DRIVER | EFI_OPEN_PROTOCOL_EXCLUSIVE: - if (controller_handle == NULL) + /* Check that the controller handle is valid */ + if (!efi_search_obj(controller_handle)) goto out; + /* fall-through */ case EFI_OPEN_PROTOCOL_EXCLUSIVE: - if (agent_handle == NULL) + /* Check that the agent handle is valid */ + if (!efi_search_obj(agent_handle)) goto out; break; default: @@ -2157,8 +2256,8 @@ static efi_status_t EFIAPI efi_open_protocol( if (r != EFI_SUCCESS) goto out;
- if (attributes != EFI_OPEN_PROTOCOL_TEST_PROTOCOL) - *protocol_interface = handler->protocol_interface; + r = efi_protocol_open(handler, protocol_interface, agent_handle, + controller_handle, attributes); out: return EFI_EXIT(r); }