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Diffstat (limited to 'FreeRTOS/Test/CBMC/proofs/Task/TaskDelay')
4 files changed, 299 insertions, 0 deletions
diff --git a/FreeRTOS/Test/CBMC/proofs/Task/TaskDelay/Configurations.json b/FreeRTOS/Test/CBMC/proofs/Task/TaskDelay/Configurations.json new file mode 100644 index 000000000..5061e8e8a --- /dev/null +++ b/FreeRTOS/Test/CBMC/proofs/Task/TaskDelay/Configurations.json @@ -0,0 +1,68 @@ +# +# FreeRTOS memory safety proofs with CBMC. +# Copyright (C) 2019 Amazon.com, Inc. or its affiliates. All Rights Reserved. +# +# Permission is hereby granted, free of charge, to any person +# obtaining a copy of this software and associated documentation +# files (the "Software"), to deal in the Software without +# restriction, including without limitation the rights to use, copy, +# modify, merge, publish, distribute, sublicense, and/or sell copies +# of the Software, and to permit persons to whom the Software is +# furnished to do so, subject to the following conditions: +# +# The above copyright notice and this permission notice shall be +# included in all copies or substantial portions of the Software. +# +# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, +# EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF +# MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND +# NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS +# BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN +# ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN +# CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE +# SOFTWARE. +# +# http://aws.amazon.com/freertos +# http://www.FreeRTOS.org +# + +{ + "ENTRY": "TaskDelay", + "DEF": + [ + { "default" : + [ + "FREERTOS_MODULE_TEST", + "PENDED_TICKS=1", + "'mtCOVERAGE_TEST_MARKER()=__CPROVER_assert(1, \"Coverage marker\")'", + "configUSE_TRACE_FACILITY=0", + "configGENERATE_RUN_TIME_STATS=0" + ] + }, + { "vTaskSuspend0" : + [ + "FREERTOS_MODULE_TEST", + "PENDED_TICKS=1", + "'mtCOVERAGE_TEST_MARKER()=__CPROVER_assert(1, \"Coverage marker\")'", + "configUSE_TRACE_FACILITY=0", + "configGENERATE_RUN_TIME_STATS=0", + "INCLUDE_vTaskSuspend=0" + ] + } + ], + "CBMCFLAGS": + [ + "--unwind 1", + "--unwindset prvInitialiseTaskLists.0:8,vListInsert.0:4" + ], + "OBJS": + [ + "$(ENTRY)_harness.goto", + "$(FREERTOS)/Source/tasks.goto", + "$(FREERTOS)/Source/list.goto" + ], + "INC": + [ + "$(FREERTOS)/Test/CBMC/proofs/Task/TaskDelay/" + ] +} diff --git a/FreeRTOS/Test/CBMC/proofs/Task/TaskDelay/README.md b/FreeRTOS/Test/CBMC/proofs/Task/TaskDelay/README.md new file mode 100644 index 000000000..f5cb3552d --- /dev/null +++ b/FreeRTOS/Test/CBMC/proofs/Task/TaskDelay/README.md @@ -0,0 +1,21 @@ +This proof demonstrates the memory safety of the TaskDelay function. We assume +that `pxCurrentTCB` is initialized and inserted in one of the ready tasks lists +(with and without another task in the same list). We abstract function +`xTaskResumeAll` by assuming that `xPendingReadyList` is empty and +`xPendedTicks` is `0`. Finally, we assume nondeterministic values for global +variables `xTickCount` and `xNextTaskUnblockTime`, and `pdFALSE` for +`uxSchedulerSuspended` (to avoid assertion failure). + +Configurations available: + + * `default`: The default configuration. + * `useTickHook1`: The default configuration with `INCLUDE_vTaskSuspend=0` + +This proof is a work-in-progress. Proof assumptions are described in +the harness. The proof also assumes the following functions are +memory safe and have no side effects relevant to the memory safety of +this function: + +* vPortEnterCritical +* vPortExitCritical +* vPortGenerateSimulatedInterrupt diff --git a/FreeRTOS/Test/CBMC/proofs/Task/TaskDelay/TaskDelay_harness.c b/FreeRTOS/Test/CBMC/proofs/Task/TaskDelay/TaskDelay_harness.c new file mode 100644 index 000000000..2ef21dedb --- /dev/null +++ b/FreeRTOS/Test/CBMC/proofs/Task/TaskDelay/TaskDelay_harness.c @@ -0,0 +1,65 @@ +/* + * FreeRTOS memory safety proofs with CBMC. + * Copyright (C) 2019 Amazon.com, Inc. or its affiliates. All Rights Reserved. + * + * Permission is hereby granted, free of charge, to any person + * obtaining a copy of this software and associated documentation + * files (the "Software"), to deal in the Software without + * restriction, including without limitation the rights to use, copy, + * modify, merge, publish, distribute, sublicense, and/or sell copies + * of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be + * included in all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, + * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF + * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND + * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS + * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN + * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN + * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE + * SOFTWARE. + * + * http://aws.amazon.com/freertos + * http://www.FreeRTOS.org + */ + +#include <stdint.h> + +/* FreeRTOS includes. */ +#include "FreeRTOS.h" +#include "task.h" + +void vSetGlobalVariables( void ); +BaseType_t xPrepareTaskLists( void ); +BaseType_t xTaskResumeAllStub( void ); + +/* + * This is a trick to overcome the "redefined twice" error + * when stubbing out the `xTaskResumeAll` function in the header + */ +BaseType_t xTaskResumeAll( void ) { + return xTaskResumeAllStub(); +} + +/* + * The harness test first calls two functions included in the tasks.c file + * that initialize the task lists and other global variables + */ +void harness() +{ + TickType_t xTicksToDelay; + BaseType_t xTasksPrepared; + + vSetGlobalVariables(); + xTasksPrepared = xPrepareTaskLists(); + + if ( xTasksPrepared != pdFAIL ) + { + vTaskDelay( xTicksToDelay ); + } +} + + diff --git a/FreeRTOS/Test/CBMC/proofs/Task/TaskDelay/tasks_test_access_functions.h b/FreeRTOS/Test/CBMC/proofs/Task/TaskDelay/tasks_test_access_functions.h new file mode 100644 index 000000000..b6b1210b0 --- /dev/null +++ b/FreeRTOS/Test/CBMC/proofs/Task/TaskDelay/tasks_test_access_functions.h @@ -0,0 +1,145 @@ +/* + * FreeRTOS memory safety proofs with CBMC. + * Copyright (C) 2019 Amazon.com, Inc. or its affiliates. All Rights Reserved. + * + * Permission is hereby granted, free of charge, to any person + * obtaining a copy of this software and associated documentation + * files (the "Software"), to deal in the Software without + * restriction, including without limitation the rights to use, copy, + * modify, merge, publish, distribute, sublicense, and/or sell copies + * of the Software, and to permit persons to whom the Software is + * furnished to do so, subject to the following conditions: + * + * The above copyright notice and this permission notice shall be + * included in all copies or substantial portions of the Software. + * + * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, + * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF + * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND + * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS + * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN + * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN + * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE + * SOFTWARE. + * + * http://aws.amazon.com/freertos + * http://www.FreeRTOS.org + */ + +#include "cbmc.h" + +/* + * We allocate a TCB and set some members to basic values + */ +TaskHandle_t xUnconstrainedTCB( void ) +{ + TCB_t * pxTCB = pvPortMalloc(sizeof(TCB_t)); + + if ( pxTCB == NULL ) + return NULL; + + __CPROVER_assume( pxTCB->uxPriority < configMAX_PRIORITIES ); + + vListInitialiseItem( &( pxTCB->xStateListItem ) ); + vListInitialiseItem( &( pxTCB->xEventListItem ) ); + + listSET_LIST_ITEM_OWNER( &( pxTCB->xStateListItem ), pxTCB ); + listSET_LIST_ITEM_OWNER( &( pxTCB->xEventListItem ), pxTCB ); + + if ( nondet_bool() ) + { + listSET_LIST_ITEM_VALUE( &( pxTCB->xStateListItem ), pxTCB->uxPriority ); + } + else + { + listSET_LIST_ITEM_VALUE( &( pxTCB->xStateListItem ), portMAX_DELAY ); + } + + if ( nondet_bool() ) + { + listSET_LIST_ITEM_VALUE( &( pxTCB->xEventListItem ), ( TickType_t ) configMAX_PRIORITIES - ( TickType_t ) pxTCB->uxPriority ); + } + else + { + listSET_LIST_ITEM_VALUE( &( pxTCB->xEventListItem ), portMAX_DELAY ); + } + return pxTCB; +} + +/* + * We set the values of relevant global variables to + * nondeterministic values, except for `uxSchedulerSuspended` + * which is set to 0 (to pass through the assertion) + */ + +void vSetGlobalVariables( void ) +{ + uxSchedulerSuspended = pdFALSE; + xTickCount = nondet_ticktype(); + xNextTaskUnblockTime = nondet_ticktype(); +} + +/* + * We initialise and fill the task lists so coverage is optimal. + * This initialization is not guaranteed to be minimal, but it + * is quite efficient and it serves the same purpose + */ +BaseType_t xPrepareTaskLists( void ) +{ + TCB_t * pxTCB = NULL; + + __CPROVER_assert_zero_allocation(); + + prvInitialiseTaskLists(); + + /* The current task will be moved to the delayed list */ + pxCurrentTCB = xUnconstrainedTCB(); + if ( pxCurrentTCB == NULL ) + { + return pdFAIL; + } + vListInsert( &pxReadyTasksLists[ pxCurrentTCB->uxPriority ], &( pxCurrentTCB->xStateListItem ) ); + + /* + * Nondeterministic insertion of a task in the ready tasks list + * guarantees coverage in line 5104 (tasks.c) + */ + if ( nondet_bool() ) + { + pxTCB = xUnconstrainedTCB(); + if ( pxTCB == NULL ) + { + return pdFAIL; + } + vListInsert( &pxReadyTasksLists[ pxTCB->uxPriority ], &( pxTCB->xStateListItem ) ); + + /* Use of this macro ensures coverage on line 185 (list.c) */ + listGET_OWNER_OF_NEXT_ENTRY( pxTCB , &pxReadyTasksLists[ pxTCB->uxPriority ] ); + } + + + return pdPASS; +} + +/* + * We stub out `xTaskResumeAll` including the assertion and change on + * variables `uxSchedulerSuspended`. We assume that `xPendingReadyList` + * is empty to avoid the first loop, and xPendedTicks to avoid the second + * one. Finally, we return a nondeterministic value (overapproximation) + */ +BaseType_t xTaskResumeAllStub( void ) +{ + BaseType_t xAlreadyYielded; + + configASSERT( uxSchedulerSuspended ); + + taskENTER_CRITICAL(); + { + --uxSchedulerSuspended; + __CPROVER_assert( listLIST_IS_EMPTY( &xPendingReadyList ), "Pending ready tasks list not empty." ); + __CPROVER_assert( xPendedTicks == 0 , "xPendedTicks is not equal to zero."); + } + taskEXIT_CRITICAL(); + + return xAlreadyYielded; +} |