[修改] 增加freeRTOS

1. 版本FreeRTOSv202212.01，命名为kernel；

kernel/FreeRTOS/Test/CBMC/proofs/Task/TaskCheckForTimeOut/Makefile.json

@@ -0,0 +1,49 @@
+#
+# 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": "TaskCheckForTimeOut",
+  "DEF":
+  [
+    "FREERTOS_MODULE_TEST",
+    "'mtCOVERAGE_TEST_MARKER()=__CPROVER_assert(1, \"Coverage marker\")'"
+  ],
+  "CBMCFLAGS":
+  [
+      "--unwind 1"
+  ],
+  "OBJS":
+  [
+    "$(ENTRY)_harness.goto",
+    "$(FREERTOS)/Source/tasks.goto"
+  ],
+  "INC":
+  [
+    "$(FREERTOS)/Test/CBMC/proofs/Task/TaskCheckForTimeOut/"
+  ]
+}

kernel/FreeRTOS/Test/CBMC/proofs/Task/TaskCheckForTimeOut/README.md

@@ -0,0 +1,10 @@
+This proof demonstrates the memory safety of the TaskCheckForTimeOut function.
+We assume `pxTimeOut`, `pxTicksToWait` and `pxCurrentTCB` to be non-NULL.
+
+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

kernel/FreeRTOS/Test/CBMC/proofs/Task/TaskCheckForTimeOut/TaskCheckForTimeOut_harness.c

@@ -0,0 +1,54 @@
+/*
+ * 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.
+ *
+ * https://aws.amazon.com/freertos
+ * https://www.FreeRTOS.org
+ */
+
+#include <stdint.h>
+
+/* FreeRTOS includes. */
+#include "FreeRTOS.h"
+#include "task.h"
+
+BaseType_t xPrepareCurrentTCB( void );
+
+/*
+ * The function requires that the function arguments `pxTimeOut` and
+ * `pxTicksToWait` and the global variable `pxCurrentTCB` are not
+ * NULL.
+ */
+void harness()
+{
+    UBaseType_t xTasksPrepared;
+    TimeOut_t pxTimeOut;
+    TickType_t pxTicksToWait;
+
+    xTasksPrepared = xPrepareCurrentTCB();
+
+    if( xTasksPrepared != pdFAIL )
+    {
+        xTaskCheckForTimeOut( &pxTimeOut, &pxTicksToWait );
+    }
+}

kernel/FreeRTOS/Test/CBMC/proofs/Task/TaskCheckForTimeOut/cbmc-viewer.json

@@ -0,0 +1,28 @@
+{ "expected-missing-functions":
+  [
+    "vApplicationTickHook",
+
+    "pxPortInitialiseStack",
+    "vPortCloseRunningThread",
+    "vPortDeleteThread",
+    "vPortEnterCritical",
+    "vPortExitCritical",
+    "vPortGenerateSimulatedInterrupt",
+    "xPortStartScheduler",
+
+    "pvTaskIncrementMutexHeldCount",
+    "uxTaskGetTaskNumber",
+    "vTaskInternalSetTimeOutState",
+    "vTaskMissedYield",
+    "vTaskPlaceOnEventList",
+    "vTaskPriorityDisinheritAfterTimeout",
+    "vTaskSuspendAll",
+    "xTaskGetCurrentTaskHandle",
+    "xTaskPriorityDisinherit",
+    "xTaskPriorityInherit",
+    "xTaskRemoveFromEventList",
+    "xTaskResumeAll"
+  ],
+  "proof-name": "TaskCheckForTimeOut",
+  "proof-root": "Test/CBMC/proofs"
+}

kernel/FreeRTOS/Test/CBMC/proofs/Task/TaskCheckForTimeOut/tasks_test_access_functions.h

@@ -0,0 +1,51 @@
+/*
+ * 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.
+ *
+ * https://aws.amazon.com/freertos
+ * https://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 ) );
+
+    return pxTCB;
+}
+
+/*
+ * We just need to allocate a totally unconstrained TCB
+ */
+BaseType_t xPrepareCurrentTCB( void )
+{
+    __CPROVER_assert_zero_allocation();
+
+    pxCurrentTCB = xUnconstrainedTCB();
+
+    return pxCurrentTCB == NULL ? pdFAIL : pdPASS;
+}

kernel/FreeRTOS/Test/CBMC/proofs/Task/TaskCreate/Makefile.json

@@ -0,0 +1,52 @@
+#
+# 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": "TaskCreate",
+  "DEF":
+  [
+    "STACK_DEPTH=10",
+    "FREERTOS_MODULE_TEST",
+    "'mtCOVERAGE_TEST_MARKER()=__CPROVER_assert(1, \"Coverage marker\")'"
+  ],
+  "CBMCFLAGS":
+  [
+      "--unwind 1",
+      "--unwindset prvInitialiseNewTask.0:16,prvInitialiseNewTask.1:4,prvInitialiseTaskLists.0:8"
+  ],
+  "OBJS":
+  [
+    "$(ENTRY)_harness.goto",
+    "$(FREERTOS)/Source/tasks.goto",
+    "$(FREERTOS)/Source/list.goto"
+  ],
+  "INC":
+  [
+    "$(FREERTOS)/Test/CBMC/proofs/Task/TaskCreate/"
+  ]
+}

kernel/FreeRTOS/Test/CBMC/proofs/Task/TaskCreate/README.md

@@ -0,0 +1,22 @@
+This proof demonstrates the memory safety of the TaskCreate function.
+We initialize task lists, but we set other data structures to
+unconstrained (arbitrary) values, including the data structures
+`pxCurrentTCB`, `uxCurrentNumberOfTasks`, `pcName` and `pxCreateTask`.
+STACK_DEPTH is set to a fixed number (10) since it is not possible to
+specify a range.
+
+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:
+
+* prvTraceGetObjectHandle
+* prvTraceGetTaskNumber
+* prvTraceSetObjectName
+* prvTraceSetPriorityProperty
+* prvTraceStoreKernelCall
+* prvTraceStoreTaskReady
+* pxPortInitialiseStack
+* vPortEnterCritical
+* vPortExitCritical
+* vPortGenerateSimulatedInterrupt

kernel/FreeRTOS/Test/CBMC/proofs/Task/TaskCreate/TaskCreate_harness.c

@@ -0,0 +1,64 @@
+/*
+ * FreeRTOS V202212.01
+ * Copyright (C) 2020 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.
+ *
+ * https://www.FreeRTOS.org
+ * https://github.com/FreeRTOS
+ *
+ */
+
+#include <stdint.h>
+
+/* FreeRTOS includes. */
+#include "FreeRTOS.h"
+#include "task.h"
+
+void vNondetSetCurrentTCB( void );
+void vSetGlobalVariables( void );
+void vPrepareTaskLists( void );
+TaskHandle_t * pxNondetSetTaskHandle( void );
+char * pcNondetSetString( size_t xSizeLength );
+
+void harness()
+{
+    TaskFunction_t pxTaskCode;
+    char * pcName;
+    configSTACK_DEPTH_TYPE usStackDepth = STACK_DEPTH;
+    void * pvParameters;
+    TaskHandle_t * pxCreatedTask;
+
+    UBaseType_t uxPriority;
+
+    __CPROVER_assume( uxPriority < configMAX_PRIORITIES );
+
+    vNondetSetCurrentTCB();
+    vSetGlobalVariables();
+    vPrepareTaskLists();
+
+    pxCreatedTask = pxNondetSetTaskHandle();
+    pcName = pcNondetSetString( configMAX_TASK_NAME_LEN );
+
+    xTaskCreate( pxTaskCode,
+                 pcName,
+                 usStackDepth,
+                 pvParameters,
+                 uxPriority,
+                 pxCreatedTask );
+}

kernel/FreeRTOS/Test/CBMC/proofs/Task/TaskCreate/cbmc-viewer.json

@@ -0,0 +1,28 @@
+{ "expected-missing-functions":
+  [
+    "vApplicationTickHook",
+
+    "pxPortInitialiseStack",
+    "vPortCloseRunningThread",
+    "vPortDeleteThread",
+    "vPortEnterCritical",
+    "vPortExitCritical",
+    "vPortGenerateSimulatedInterrupt",
+    "xPortStartScheduler",
+
+    "pvTaskIncrementMutexHeldCount",
+    "uxTaskGetTaskNumber",
+    "vTaskInternalSetTimeOutState",
+    "vTaskMissedYield",
+    "vTaskPlaceOnEventList",
+    "vTaskPriorityDisinheritAfterTimeout",
+    "vTaskSuspendAll",
+    "xTaskGetCurrentTaskHandle",
+    "xTaskPriorityDisinherit",
+    "xTaskPriorityInherit",
+    "xTaskRemoveFromEventList",
+    "xTaskResumeAll"
+  ],
+  "proof-name": "TaskCreate",
+  "proof-root": "Test/CBMC/proofs"
+}

kernel/FreeRTOS/Test/CBMC/proofs/Task/TaskCreate/tasks_test_access_functions.h

@@ -0,0 +1,87 @@
+/*
+ * 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.
+ *
+ * https://aws.amazon.com/freertos
+ * https://www.FreeRTOS.org
+ */
+
+#include "cbmc.h"
+
+/*
+ * Our stub for pvPortMalloc in cbmc.h nondeterministically chooses
+ * either to return NULL or to allocate the requested memory.
+ */
+void vNondetSetCurrentTCB( void )
+{
+    pxCurrentTCB = pvPortMalloc( sizeof( TCB_t ) );
+}
+
+/*
+ * We just require task lists to be initialized for this proof
+ */
+void vPrepareTaskLists( void )
+{
+    __CPROVER_assert_zero_allocation();
+
+    prvInitialiseTaskLists();
+}
+
+/*
+ * We set the values of relevant global
+ * variables to nondeterministic values
+ */
+void vSetGlobalVariables( void )
+{
+    xSchedulerRunning = nondet_basetype();
+    uxCurrentNumberOfTasks = nondet_ubasetype();
+}
+
+/*
+ * pvPortMalloc is nondeterministic by definition, thus we do not need
+ * to check for NULL allocation in this function
+ */
+TaskHandle_t * pxNondetSetTaskHandle( void )
+{
+    TaskHandle_t * pxNondetTaskHandle = pvPortMalloc( sizeof( TaskHandle_t ) );
+
+    return pxNondetTaskHandle;
+}
+
+/*
+ * Tries to allocate a string of size xStringLength and sets the string
+ * to be terminated using a nondeterministic index if allocation was successful
+ */
+char * pcNondetSetString( size_t xStringLength )
+{
+    char * pcName = pvPortMalloc( xStringLength );
+
+    if( pcName != NULL )
+    {
+        size_t uNondetIndex;
+        __CPROVER_assume( uNondetIndex < xStringLength );
+        pcName[ uNondetIndex ] = '\0';
+    }
+
+    return pcName;
+}

kernel/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/"
+  ]
+}

kernel/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

kernel/FreeRTOS/Test/CBMC/proofs/Task/TaskDelay/TaskDelay_harness.c

@@ -0,0 +1,64 @@
+/*
+ * 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.
+ *
+ * https://aws.amazon.com/freertos
+ * https://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 );
+    }
+}

kernel/FreeRTOS/Test/CBMC/proofs/Task/TaskDelay/cbmc-viewer.json

@@ -0,0 +1,28 @@
+{ "expected-missing-functions":
+  [
+    "vApplicationTickHook",
+
+    "pxPortInitialiseStack",
+    "vPortCloseRunningThread",
+    "vPortDeleteThread",
+    "vPortEnterCritical",
+    "vPortExitCritical",
+    "vPortGenerateSimulatedInterrupt",
+    "xPortStartScheduler",
+
+    "pvTaskIncrementMutexHeldCount",
+    "uxTaskGetTaskNumber",
+    "vTaskInternalSetTimeOutState",
+    "vTaskMissedYield",
+    "vTaskPlaceOnEventList",
+    "vTaskPriorityDisinheritAfterTimeout",
+    "vTaskSuspendAll",
+    "xTaskGetCurrentTaskHandle",
+    "xTaskPriorityDisinherit",
+    "xTaskPriorityInherit",
+    "xTaskRemoveFromEventList",
+    "xTaskResumeAll"
+  ],
+  "proof-name": "TaskDelay",
+  "proof-root": "Test/CBMC/proofs"
+}

kernel/FreeRTOS/Test/CBMC/proofs/Task/TaskDelay/tasks_test_access_functions.h

@@ -0,0 +1,151 @@
+/*
+ * 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.
+ *
+ * https://aws.amazon.com/freertos
+ * https://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;
+}

kernel/FreeRTOS/Test/CBMC/proofs/Task/TaskDelete/Makefile.json

@@ -0,0 +1,55 @@
+#
+# 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": "TaskDelete",
+  "DEF":
+  [
+    "FREERTOS_MODULE_TEST",
+    "'mtCOVERAGE_TEST_MARKER()=__CPROVER_assert(1, \"Coverage marker\")'",
+    "STACK_DEPTH=10",
+    "configUSE_TRACE_FACILITY=0",
+    "configGENERATE_RUN_TIME_STATS=0"
+  ],
+  "CBMCFLAGS":
+  [
+    "--unwind 1",
+    "--unwindset prvInitialiseTaskLists.0:8,vListInsert.0:3"
+
+  ],
+  "OBJS":
+  [
+    "$(ENTRY)_harness.goto",
+    "$(FREERTOS)/Source/tasks.goto",
+    "$(FREERTOS)/Source/list.goto"
+  ],
+  "INC":
+  [
+    "$(FREERTOS)/Test/CBMC/proofs/Task/TaskDelete/"
+  ]
+}

kernel/FreeRTOS/Test/CBMC/proofs/Task/TaskDelete/README.md

@@ -0,0 +1,19 @@
+This proof demonstrates the memory safety of the TaskDelete function.  The
+initialization for the task to be delete and `pxCurrentTCB` is quite similar
+(since the task handle may be NULL, and in that case `pxCurrentTCB` is used).
+The task to be deleted requires the stack in the task control block to be
+allocated, and the flag for static allocation to be properly set (i.e., valid
+values as defined by the macros) Task lists are initialized with these tasks
+and nondet. filled with a few more items.  We assume a nondet. value for
+`xSchedulerRunning`.
+
+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:
+
+* vPortCloseRunningThread
+* vPortDeleteThread
+* vPortEnterCritical
+* vPortExitCritical
+* vPortGenerateSimulatedInterrupt

kernel/FreeRTOS/Test/CBMC/proofs/Task/TaskDelete/TaskDelete_harness.c

@@ -0,0 +1,54 @@
+/*
+ * 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.
+ *
+ * https://aws.amazon.com/freertos
+ * https://www.FreeRTOS.org
+ */
+
+#include <stdint.h>
+
+/* FreeRTOS includes. */
+#include "FreeRTOS.h"
+#include "task.h"
+
+void vSetGlobalVariables();
+BaseType_t xPrepareTaskLists( TaskHandle_t * xTask );
+
+/*
+ * The harness test first calls two functions included in the tasks.c file
+ * that initialize the task lists and other global variables
+ */
+void harness()
+{
+    TaskHandle_t xTaskToDelete;
+    BaseType_t xTasksPrepared;
+
+    vSetGlobalVariables();
+    xTasksPrepared = xPrepareTaskLists( &xTaskToDelete );
+
+    if( xTasksPrepared != pdFAIL )
+    {
+        vTaskDelete( xTaskToDelete );
+    }
+}

kernel/FreeRTOS/Test/CBMC/proofs/Task/TaskDelete/cbmc-viewer.json

@@ -0,0 +1,28 @@
+{ "expected-missing-functions":
+  [
+    "vApplicationTickHook",
+
+    "pxPortInitialiseStack",
+    "vPortCloseRunningThread",
+    "vPortDeleteThread",
+    "vPortEnterCritical",
+    "vPortExitCritical",
+    "vPortGenerateSimulatedInterrupt",
+    "xPortStartScheduler",
+
+    "pvTaskIncrementMutexHeldCount",
+    "uxTaskGetTaskNumber",
+    "vTaskInternalSetTimeOutState",
+    "vTaskMissedYield",
+    "vTaskPlaceOnEventList",
+    "vTaskPriorityDisinheritAfterTimeout",
+    "vTaskSuspendAll",
+    "xTaskGetCurrentTaskHandle",
+    "xTaskPriorityDisinherit",
+    "xTaskPriorityInherit",
+    "xTaskRemoveFromEventList",
+    "xTaskResumeAll"
+  ],
+  "proof-name": "TaskDelete",
+  "proof-root": "Test/CBMC/proofs"
+}

kernel/FreeRTOS/Test/CBMC/proofs/Task/TaskDelete/tasks_test_access_functions.h

@@ -0,0 +1,181 @@
+/*
+ * 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.
+ *
+ * https://aws.amazon.com/freertos
+ * https://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 ) );
+    uint8_t ucStaticAllocationFlag;
+
+    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 );
+    }
+
+    pxTCB->pxStack = ( StackType_t * ) pvPortMalloc( ( ( ( size_t ) STACK_DEPTH ) * sizeof( StackType_t ) ) );
+
+    if( pxTCB->pxStack == NULL )
+    {
+        vPortFree( pxTCB );
+        return NULL;
+    }
+
+    __CPROVER_assume( ucStaticAllocationFlag <= tskSTATICALLY_ALLOCATED_STACK_AND_TCB );
+    __CPROVER_assume( ucStaticAllocationFlag >= tskDYNAMICALLY_ALLOCATED_STACK_AND_TCB );
+    pxTCB->ucStaticallyAllocated = ucStaticAllocationFlag;
+
+    return pxTCB;
+}
+
+/*
+ * We set the values of relevant global
+ * variables to nondeterministic values
+ */
+void vSetGlobalVariables()
+{
+    xSchedulerRunning = nondet_basetype();
+}
+
+/*
+ * 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( TaskHandle_t * xTask )
+{
+    TCB_t * pxTCB = NULL;
+
+    __CPROVER_assert_zero_allocation();
+
+    prvInitialiseTaskLists();
+
+    /*
+     * The task handle passed to TaskDelete can be NULL. In that case, the
+     * task to delete is the one in `pxCurrentTCB`, see the macro `prvGetTCBFromHandle`
+     * in line 1165 (tasks.c) for reference. For that reason, we provide a similar
+     * initialization for an arbitrary task `pxTCB` and `pxCurrentTCB`.
+     */
+
+    pxTCB = xUnconstrainedTCB();
+
+    if( pxTCB != NULL )
+    {
+        if( nondet_bool() )
+        {
+            TCB_t * pxOtherTCB;
+            pxOtherTCB = xUnconstrainedTCB();
+
+            /*
+             * Nondeterministic insertion of another TCB in the same list
+             * to guarantee coverage in line 1174 (tasks.c)
+             */
+            if( pxOtherTCB != NULL )
+            {
+                vListInsert( &xPendingReadyList, &( pxOtherTCB->xStateListItem ) );
+            }
+        }
+
+        vListInsert( &xPendingReadyList, &( pxTCB->xStateListItem ) );
+
+        /*
+         * Nondeterministic insertion of an event list item to guarantee
+         * coverage in lines 1180-1184 (tasks.c)
+         */
+        if( nondet_bool() )
+        {
+            vListInsert( pxDelayedTaskList, &( pxTCB->xEventListItem ) );
+        }
+    }
+
+    /* Note that `*xTask = NULL` can happen here, but this is fine -- `pxCurrentTCB` will be used instead */
+    *xTask = pxTCB;
+
+    /*
+     * `pxCurrentTCB` must be initialized the same way as the previous task, but an
+     * allocation failure cannot happen in this case (i.e., if the previous task is NULL)
+     */
+    pxCurrentTCB = xUnconstrainedTCB();
+
+    if( pxCurrentTCB == NULL )
+    {
+        return pdFAIL;
+    }
+
+    if( nondet_bool() )
+    {
+        TCB_t * pxOtherTCB;
+        pxOtherTCB = xUnconstrainedTCB();
+
+        if( pxOtherTCB != NULL )
+        {
+            vListInsert( &pxReadyTasksLists[ pxOtherTCB->uxPriority ], &( pxOtherTCB->xStateListItem ) );
+        }
+    }
+
+    vListInsert( &pxReadyTasksLists[ pxCurrentTCB->uxPriority ], &( pxCurrentTCB->xStateListItem ) );
+
+    /* Use of this macro ensures coverage on line 185 (list.c) */
+    listGET_OWNER_OF_NEXT_ENTRY( pxCurrentTCB, &pxReadyTasksLists[ pxCurrentTCB->uxPriority ] );
+
+    if( nondet_bool() )
+    {
+        vListInsert( pxDelayedTaskList, &( pxCurrentTCB->xEventListItem ) );
+    }
+
+    return pdPASS;
+}

kernel/FreeRTOS/Test/CBMC/proofs/Task/TaskGetCurrentTaskHandle/Makefile.json

@@ -0,0 +1,51 @@
+#
+# 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": "TaskGetCurrentTaskHandle",
+  "DEF":
+  [
+    "FREERTOS_MODULE_TEST",
+    "'mtCOVERAGE_TEST_MARKER()=__CPROVER_assert(1, \"Coverage marker\")'"
+  ],
+  "CBMCFLAGS":
+  [
+    "--unwind 1"
+  ],
+  "OBJS":
+  [
+    "$(ENTRY)_harness.goto",
+    "$(FREERTOS)/Source/tasks.goto",
+    "$(FREERTOS)/Source/list.goto"
+  ],
+  "INC":
+  [
+    "$(FREERTOS)/Source/",
+    "$(FREERTOS)/Test/CBMC/proofs/Task/TaskGetCurrentTaskHandle/"
+  ]
+}

kernel/FreeRTOS/Test/CBMC/proofs/Task/TaskGetCurrentTaskHandle/README.md

@@ -0,0 +1,6 @@
+This proof demonstrates the memory safety of the TaskGetCurrentTaskHandle
+function.  We assume that `pxCurrentTCB` is not NULL and we check that the
+return value is not NULL.
+
+This proof is a work-in-progress.  Proof assumptions are described in
+the harness.

kernel/FreeRTOS/Test/CBMC/proofs/Task/TaskGetCurrentTaskHandle/TaskGetCurrentTaskHandle_harness.c

@@ -0,0 +1,54 @@
+/*
+ * 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.
+ *
+ * https://aws.amazon.com/freertos
+ * https://www.FreeRTOS.org
+ */
+
+#include <stdint.h>
+
+/* FreeRTOS includes. */
+#include "FreeRTOS.h"
+#include "task.h"
+
+BaseType_t xPrepareCurrentTCB( void );
+
+/*
+ * We set pxCurrentTCB to an unconstrained TCB. Then we call
+ * xTaskGetCurrentTaskHandle() and check the return value is not NULL
+ */
+void harness()
+{
+    TaskHandle_t xTask;
+    BaseType_t xTasksPrepared;
+
+    xTasksPrepared = xPrepareCurrentTCB();
+
+    if( xTasksPrepared != pdFAIL )
+    {
+        xTask = xTaskGetCurrentTaskHandle();
+
+        __CPROVER_assert( xTask != NULL, "Current task handle is NULL!" );
+    }
+}

kernel/FreeRTOS/Test/CBMC/proofs/Task/TaskGetCurrentTaskHandle/cbmc-viewer.json

@@ -0,0 +1,28 @@
+{ "expected-missing-functions":
+  [
+    "vApplicationTickHook",
+
+    "pxPortInitialiseStack",
+    "vPortCloseRunningThread",
+    "vPortDeleteThread",
+    "vPortEnterCritical",
+    "vPortExitCritical",
+    "vPortGenerateSimulatedInterrupt",
+    "xPortStartScheduler",
+
+    "pvTaskIncrementMutexHeldCount",
+    "uxTaskGetTaskNumber",
+    "vTaskInternalSetTimeOutState",
+    "vTaskMissedYield",
+    "vTaskPlaceOnEventList",
+    "vTaskPriorityDisinheritAfterTimeout",
+    "vTaskSuspendAll",
+    "xTaskGetCurrentTaskHandle",
+    "xTaskPriorityDisinherit",
+    "xTaskPriorityInherit",
+    "xTaskRemoveFromEventList",
+    "xTaskResumeAll"
+  ],
+  "proof-name": "TaskGetCurrentTaskHandle",
+  "proof-root": "Test/CBMC/proofs"
+}

kernel/FreeRTOS/Test/CBMC/proofs/Task/TaskGetCurrentTaskHandle/tasks_test_access_functions.h

@@ -0,0 +1,61 @@
+/*
+ * 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.
+ *
+ * https://aws.amazon.com/freertos
+ * https://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;
+    }
+
+    return pxTCB;
+}
+
+/*
+ * We just need to allocate a totally unconstrained TCB
+ */
+BaseType_t xPrepareCurrentTCB( void )
+{
+    __CPROVER_assert_zero_allocation();
+
+    pxCurrentTCB = xUnconstrainedTCB();
+
+    if( pxCurrentTCB == NULL )
+    {
+        return pdFAIL;
+    }
+
+    return pdPASS;
+}

kernel/FreeRTOS/Test/CBMC/proofs/Task/TaskGetSchedulerState/Makefile.json

@@ -0,0 +1,49 @@
+#
+# 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": "TaskGetSchedulerState",
+  "DEF":
+  [
+    "FREERTOS_MODULE_TEST",
+    "'mtCOVERAGE_TEST_MARKER()=__CPROVER_assert(1, \"Coverage marker\")'"
+  ],
+  "CBMCFLAGS":
+  [
+      "--unwind 1"
+  ],
+  "OBJS":
+  [
+    "$(ENTRY)_harness.goto",
+    "$(FREERTOS)/Source/tasks.goto"
+  ],
+  "INC":
+  [
+    "$(FREERTOS)/Test/CBMC/proofs/Task/TaskGetSchedulerState/"
+  ]
+}

kernel/FreeRTOS/Test/CBMC/proofs/Task/TaskGetSchedulerState/README.md

@@ -0,0 +1,6 @@
+This proof demonstrates the memory safety of the TaskGetSchedulerState function.
+We assume `xSchedulerRunning` and `uxSchedulerSuspended` to be nondeterministic values.
+
+This proof is a work-in-progress.  Proof assumptions are described in
+the harness.
+

kernel/FreeRTOS/Test/CBMC/proofs/Task/TaskGetSchedulerState/TaskGetSchedulerState_harness.c

@@ -0,0 +1,48 @@
+/*
+ * 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.
+ *
+ * https://aws.amazon.com/freertos
+ * https://www.FreeRTOS.org
+ */
+
+#include <stdint.h>
+
+/* FreeRTOS includes. */
+#include "FreeRTOS.h"
+#include "task.h"
+
+void vSetGlobalVariables( void );
+
+/*
+ * We just require scheduler flags to be nondeterministic
+ * values before calling `xTaskGetSchedulerState`
+ */
+void harness()
+{
+    BaseType_t xResult;
+
+    vSetGlobalVariables();
+
+    xResult = xTaskGetSchedulerState();
+}

kernel/FreeRTOS/Test/CBMC/proofs/Task/TaskGetSchedulerState/cbmc-viewer.json

@@ -0,0 +1,28 @@
+{ "expected-missing-functions":
+  [
+    "vApplicationTickHook",
+
+    "pxPortInitialiseStack",
+    "vPortCloseRunningThread",
+    "vPortDeleteThread",
+    "vPortEnterCritical",
+    "vPortExitCritical",
+    "vPortGenerateSimulatedInterrupt",
+    "xPortStartScheduler",
+
+    "pvTaskIncrementMutexHeldCount",
+    "uxTaskGetTaskNumber",
+    "vTaskInternalSetTimeOutState",
+    "vTaskMissedYield",
+    "vTaskPlaceOnEventList",
+    "vTaskPriorityDisinheritAfterTimeout",
+    "vTaskSuspendAll",
+    "xTaskGetCurrentTaskHandle",
+    "xTaskPriorityDisinherit",
+    "xTaskPriorityInherit",
+    "xTaskRemoveFromEventList",
+    "xTaskResumeAll"
+  ],
+  "proof-name": "TaskGetSchedulerState",
+  "proof-root": "Test/CBMC/proofs"
+}

kernel/FreeRTOS/Test/CBMC/proofs/Task/TaskGetSchedulerState/tasks_test_access_functions.h

@@ -0,0 +1,37 @@
+/*
+ * 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.
+ *
+ * https://aws.amazon.com/freertos
+ * https://www.FreeRTOS.org
+ */
+
+/*
+ * We set the values of relevant global
+ * variables to nondeterministic values
+ */
+void vSetGlobalVariables( void )
+{
+    xSchedulerRunning = nondet_basetype();
+    uxSchedulerSuspended = nondet_ubasetype();
+}

kernel/FreeRTOS/Test/CBMC/proofs/Task/TaskGetTaskNumber/Makefile.json

@@ -0,0 +1,49 @@
+#
+# 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": "TaskGetTaskNumber",
+  "DEF":
+  [
+    "FREERTOS_MODULE_TEST",
+    "'mtCOVERAGE_TEST_MARKER()=__CPROVER_assert(1, \"Coverage marker\")'"
+  ],
+  "CBMCFLAGS":
+  [
+      "--unwind 1"
+  ],
+  "OBJS":
+  [
+    "$(ENTRY)_harness.goto",
+    "$(FREERTOS)/Source/tasks.goto"
+  ],
+  "INC":
+  [
+    "$(FREERTOS)/Test/CBMC/proofs/Task/TaskGetTaskNumber/"
+  ]
+}

kernel/FreeRTOS/Test/CBMC/proofs/Task/TaskGetTaskNumber/README.md

@@ -0,0 +1,5 @@
+This proof demonstrates the memory safety of the TaskGetTaskNumber function.
+No assumption is required since the function accepts a NULL value for the task handle.
+
+This proof is a work-in-progress.  Proof assumptions are described in
+the harness.

kernel/FreeRTOS/Test/CBMC/proofs/Task/TaskGetTaskNumber/TaskGetTaskNumber_harness.c

@@ -0,0 +1,49 @@
+/*
+ * 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.
+ *
+ * https://aws.amazon.com/freertos
+ * https://www.FreeRTOS.org
+ */
+
+#include <stdint.h>
+
+/* FreeRTOS includes. */
+#include "FreeRTOS.h"
+#include "task.h"
+
+void vPrepareTask( TaskHandle_t * xTask );
+
+/*
+ * We prepare an unconstrained task (possibly NULL)
+ * and then call `uxTaskGetTaskNumber`
+ */
+void harness()
+{
+    TaskHandle_t xTask;
+    UBaseType_t uxTaskNumber;
+
+    vPrepareTask( &xTask );
+
+    uxTaskNumber = uxTaskGetTaskNumber( xTask );
+}

kernel/FreeRTOS/Test/CBMC/proofs/Task/TaskGetTaskNumber/cbmc-viewer.json

@@ -0,0 +1,28 @@
+{ "expected-missing-functions":
+  [
+    "vApplicationTickHook",
+
+    "pxPortInitialiseStack",
+    "vPortCloseRunningThread",
+    "vPortDeleteThread",
+    "vPortEnterCritical",
+    "vPortExitCritical",
+    "vPortGenerateSimulatedInterrupt",
+    "xPortStartScheduler",
+
+    "pvTaskIncrementMutexHeldCount",
+    "uxTaskGetTaskNumber",
+    "vTaskInternalSetTimeOutState",
+    "vTaskMissedYield",
+    "vTaskPlaceOnEventList",
+    "vTaskPriorityDisinheritAfterTimeout",
+    "vTaskSuspendAll",
+    "xTaskGetCurrentTaskHandle",
+    "xTaskPriorityDisinherit",
+    "xTaskPriorityInherit",
+    "xTaskRemoveFromEventList",
+    "xTaskResumeAll"
+  ],
+  "proof-name": "TaskGetTaskNumber",
+  "proof-root": "Test/CBMC/proofs"
+}

kernel/FreeRTOS/Test/CBMC/proofs/Task/TaskGetTaskNumber/tasks_test_access_functions.h

@@ -0,0 +1,55 @@
+/*
+ * 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.
+ *
+ * https://aws.amazon.com/freertos
+ * https://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;
+    }
+
+    return pxTCB;
+}
+
+/*
+ * We try to allocate an unconstrained TCB but do not
+ * check for NULL errors here (the function does it)
+ */
+void vPrepareTask( TaskHandle_t * xTask )
+{
+    __CPROVER_assert_zero_allocation();
+
+    *xTask = xUnconstrainedTCB();
+}

kernel/FreeRTOS/Test/CBMC/proofs/Task/TaskGetTickCount/Makefile.json

@@ -0,0 +1,40 @@
+#
+# 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": "TaskGetTickCount",
+  "CBMCFLAGS":
+  [
+      "--unwind 1"
+  ],
+  "OBJS":
+  [
+    "$(ENTRY)_harness.goto",
+    "$(FREERTOS)/Source/tasks.goto"
+  ]
+}

kernel/FreeRTOS/Test/CBMC/proofs/Task/TaskGetTickCount/README.md

@@ -0,0 +1,5 @@
+This proof demonstrates the memory safety of the TaskIncrementTick function.
+No assumptions nor abstractions are required for single-threaded computation.
+
+This proof is a work-in-progress.  Proof assumptions are described in
+the harness.

kernel/FreeRTOS/Test/CBMC/proofs/Task/TaskGetTickCount/TaskGetTickCount_harness.c

@@ -0,0 +1,40 @@
+/*
+ * 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.
+ *
+ * https://aws.amazon.com/freertos
+ * https://www.FreeRTOS.org
+ */
+
+#include <stdint.h>
+
+/* FreeRTOS includes. */
+#include "FreeRTOS.h"
+#include "task.h"
+
+void harness()
+{
+    TickType_t xTickCount;
+
+    xTickCount = xTaskGetTickCount();
+}

kernel/FreeRTOS/Test/CBMC/proofs/Task/TaskGetTickCount/cbmc-viewer.json

@@ -0,0 +1,28 @@
+{ "expected-missing-functions":
+  [
+    "vApplicationTickHook",
+
+    "pxPortInitialiseStack",
+    "vPortCloseRunningThread",
+    "vPortDeleteThread",
+    "vPortEnterCritical",
+    "vPortExitCritical",
+    "vPortGenerateSimulatedInterrupt",
+    "xPortStartScheduler",
+
+    "pvTaskIncrementMutexHeldCount",
+    "uxTaskGetTaskNumber",
+    "vTaskInternalSetTimeOutState",
+    "vTaskMissedYield",
+    "vTaskPlaceOnEventList",
+    "vTaskPriorityDisinheritAfterTimeout",
+    "vTaskSuspendAll",
+    "xTaskGetCurrentTaskHandle",
+    "xTaskPriorityDisinherit",
+    "xTaskPriorityInherit",
+    "xTaskRemoveFromEventList",
+    "xTaskResumeAll"
+  ],
+  "proof-name": "TaskGetTickCount",
+  "proof-root": "Test/CBMC/proofs"
+}

kernel/FreeRTOS/Test/CBMC/proofs/Task/TaskIncrementTick/Configurations.json

@@ -0,0 +1,63 @@
+#
+# 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": "TaskIncrementTick",
+  "DEF":
+  [
+    { "default":
+      [
+        "FREERTOS_MODULE_TEST",
+        "'mtCOVERAGE_TEST_MARKER()=__CPROVER_assert(1, \"Coverage marker\")'",
+	"configUSE_TICK_HOOK=0"
+      ]
+    },
+    { "useTickHook1":
+      [
+        "FREERTOS_MODULE_TEST",
+        "'mtCOVERAGE_TEST_MARKER()=__CPROVER_assert(1, \"Coverage marker\")'",
+        "configUSE_TICK_HOOK=1"
+      ]
+    }
+  ],
+  "CBMCFLAGS":
+  [
+    "--unwind 1",
+    "--unwindset prvInitialiseTaskLists.0:8,vListInsert.0:2,xTaskIncrementTick.0:4"
+  ],
+  "OBJS":
+  [
+    "$(ENTRY)_harness.goto",
+    "$(FREERTOS)/Source/tasks.goto",
+    "$(FREERTOS)/Source/list.goto"
+  ],
+  "INC":
+  [
+    "$(FREERTOS)/Test/CBMC/proofs/Task/TaskIncrementTick/"
+  ]
+}

kernel/FreeRTOS/Test/CBMC/proofs/Task/TaskIncrementTick/README.md

@@ -0,0 +1,18 @@
+This proof demonstrates the memory safety of the TaskIncrementTick function.
+We assume that task lists are initialized and filled with a few list items. We
+also assign nondeterministic values to some global variables.
+
+Configurations available:
+ * `default`: The default configuration.  `useTickHook1`: The default
+ * configuration with `configUSE_TICK_HOOK=1`
+
+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:
+
+* prvTraceGetTaskNumber
+* prvTracePortGetTimeStamp
+* prvTraceStoreKernelCallWithNumericParamOnly
+* prvTraceStoreTaskReady
+* vApplicationTickHook

kernel/FreeRTOS/Test/CBMC/proofs/Task/TaskIncrementTick/TaskIncrementTick_harness.c

@@ -0,0 +1,53 @@
+/*
+ * 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.
+ *
+ * https://aws.amazon.com/freertos
+ * https://www.FreeRTOS.org
+ */
+
+#include <stdint.h>
+
+/* FreeRTOS includes. */
+#include "FreeRTOS.h"
+#include "task.h"
+
+void vSetGlobalVariables();
+BaseType_t xPrepareTaskLists( void );
+
+/*
+ * The harness test first calls two functions included in the tasks.c file
+ * that initialize the task lists and other global variables
+ */
+void harness()
+{
+    BaseType_t xTasksPrepared;
+
+    vSetGlobalVariables();
+    xTasksPrepared = xPrepareTaskLists();
+
+    if( xTasksPrepared != pdFAIL )
+    {
+        xTaskIncrementTick();
+    }
+}

kernel/FreeRTOS/Test/CBMC/proofs/Task/TaskIncrementTick/cbmc-viewer.json

@@ -0,0 +1,28 @@
+{ "expected-missing-functions":
+  [
+    "vApplicationTickHook",
+
+    "pxPortInitialiseStack",
+    "vPortCloseRunningThread",
+    "vPortDeleteThread",
+    "vPortEnterCritical",
+    "vPortExitCritical",
+    "vPortGenerateSimulatedInterrupt",
+    "xPortStartScheduler",
+
+    "pvTaskIncrementMutexHeldCount",
+    "uxTaskGetTaskNumber",
+    "vTaskInternalSetTimeOutState",
+    "vTaskMissedYield",
+    "vTaskPlaceOnEventList",
+    "vTaskPriorityDisinheritAfterTimeout",
+    "vTaskSuspendAll",
+    "xTaskGetCurrentTaskHandle",
+    "xTaskPriorityDisinherit",
+    "xTaskPriorityInherit",
+    "xTaskRemoveFromEventList",
+    "xTaskResumeAll"
+  ],
+  "proof-name": "TaskIncrementTick",
+  "proof-root": "Test/CBMC/proofs"
+}

kernel/FreeRTOS/Test/CBMC/proofs/Task/TaskIncrementTick/tasks_test_access_functions.h

@@ -0,0 +1,135 @@
+/*
+ * 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.
+ *
+ * https://aws.amazon.com/freertos
+ * https://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
+ */
+void vSetGlobalVariables()
+{
+    xPendedTicks = nondet_ubasetype();
+    uxSchedulerSuspended = nondet_ubasetype();
+    xYieldPending = nondet_basetype();
+    xTickCount = 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();
+
+    /* Needed for coverage: This task will be moved to a ready list */
+    pxTCB = xUnconstrainedTCB();
+
+    if( pxTCB == NULL )
+    {
+        return pdFAIL;
+    }
+
+    vListInsert( pxOverflowDelayedTaskList, &( pxTCB->xStateListItem ) );
+
+    /* Needed for coverage. */
+    listGET_OWNER_OF_NEXT_ENTRY( pxTCB, pxOverflowDelayedTaskList );
+
+    pxTCB = xUnconstrainedTCB();
+
+    if( pxTCB == NULL )
+    {
+        return pdFAIL;
+    }
+
+    vListInsert( &xPendingReadyList, &( pxTCB->xStateListItem ) );
+
+    /* Needed for coverage: A nondeterministic choice */
+    if( nondet_bool() )
+    {
+        vListInsert( pxOverflowDelayedTaskList, &( pxTCB->xEventListItem ) );
+    }
+
+    pxCurrentTCB = xUnconstrainedTCB();
+
+    if( pxCurrentTCB == NULL )
+    {
+        return pdFAIL;
+    }
+
+    vListInsert( &pxReadyTasksLists[ pxCurrentTCB->uxPriority ], &( pxCurrentTCB->xStateListItem ) );
+
+    return pdPASS;
+}

kernel/FreeRTOS/Test/CBMC/proofs/Task/TaskPrioritySet/Makefile.json

@@ -0,0 +1,54 @@
+#
+# 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": "TaskPrioritySet",
+  "DEF":
+  [
+    "FREERTOS_MODULE_TEST",
+    "'mtCOVERAGE_TEST_MARKER()=__CPROVER_assert(1, \"Coverage marker\")'",
+    "configUSE_TRACE_FACILITY=0",
+    "configGENERATE_RUN_TIME_STATS=0"
+  ],
+  "CBMCFLAGS":
+  [
+    "--unwind 1",
+    "--unwindset prvInitialiseTaskLists.0:8,vListInsert.0:3"
+
+  ],
+  "OBJS":
+  [
+    "$(ENTRY)_harness.goto",
+    "$(FREERTOS)/Source/tasks.goto",
+    "$(FREERTOS)/Source/list.goto"
+  ],
+  "INC":
+  [
+    "$(FREERTOS)/Test/CBMC/proofs/Task/TaskPrioritySet/"
+  ]
+}

kernel/FreeRTOS/Test/CBMC/proofs/Task/TaskPrioritySet/README.md

@@ -0,0 +1,14 @@
+This proof demonstrates the memory safety of the TaskPrioritySet function.  The
+initialization for the task to be set and `pxCurrentTCB` is quite similar
+(since the task handle may be NULL, and in that case `pxCurrentTCB` is used).
+Task lists are initialized with these tasks and nondet. filled with a few more
+items.
+
+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

kernel/FreeRTOS/Test/CBMC/proofs/Task/TaskPrioritySet/TaskPrioritySet_harness.c

@@ -0,0 +1,57 @@
+/*
+ * 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.
+ *
+ * https://aws.amazon.com/freertos
+ * https://www.FreeRTOS.org
+ */
+
+#include <stdint.h>
+
+/* FreeRTOS includes. */
+#include "FreeRTOS.h"
+#include "task.h"
+
+BaseType_t xPrepareTaskLists( TaskHandle_t * xTask );
+
+/*
+ * We assume `uxNewPriority` to be a valid priority (avoids failed assert).
+ * The harness test first calls two functions included in the tasks.c file
+ * that initialize the task lists and other global variables
+ */
+void harness()
+{
+    TaskHandle_t xTask;
+    UBaseType_t uxNewPriority;
+    BaseType_t xTasksPrepared;
+
+    __CPROVER_assume( uxNewPriority < configMAX_PRIORITIES );
+
+    xTasksPrepared = xPrepareTaskLists( &xTask );
+
+    /* Check that this second invocation of xPrepareTaskLists is needed. */
+    if( xPrepareTaskLists( &xTask ) != pdFAIL )
+    {
+        vTaskPrioritySet( xTask, uxNewPriority );
+    }
+}

kernel/FreeRTOS/Test/CBMC/proofs/Task/TaskPrioritySet/cbmc-viewer.json

@@ -0,0 +1,28 @@
+{ "expected-missing-functions":
+  [
+    "vApplicationTickHook",
+
+    "pxPortInitialiseStack",
+    "vPortCloseRunningThread",
+    "vPortDeleteThread",
+    "vPortEnterCritical",
+    "vPortExitCritical",
+    "vPortGenerateSimulatedInterrupt",
+    "xPortStartScheduler",
+
+    "pvTaskIncrementMutexHeldCount",
+    "uxTaskGetTaskNumber",
+    "vTaskInternalSetTimeOutState",
+    "vTaskMissedYield",
+    "vTaskPlaceOnEventList",
+    "vTaskPriorityDisinheritAfterTimeout",
+    "vTaskSuspendAll",
+    "xTaskGetCurrentTaskHandle",
+    "xTaskPriorityDisinherit",
+    "xTaskPriorityInherit",
+    "xTaskRemoveFromEventList",
+    "xTaskResumeAll"
+  ],
+  "proof-name": "TaskPrioritySet",
+  "proof-root": "Test/CBMC/proofs"
+}

kernel/FreeRTOS/Test/CBMC/proofs/Task/TaskPrioritySet/tasks_test_access_functions.h

@@ -0,0 +1,129 @@
+/*
+ * 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.
+ *
+ * https://aws.amazon.com/freertos
+ * https://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 ) );
+    uint8_t ucStaticAllocationFlag;
+
+    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 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( TaskHandle_t * xTask )
+{
+    TCB_t * pxTCB = NULL;
+
+    __CPROVER_assert_zero_allocation();
+
+    prvInitialiseTaskLists();
+
+    pxTCB = xUnconstrainedTCB();
+
+    /* Needed for coverage: nondet insertion of task. */
+    if( nondet_bool() )
+    {
+        TCB_t * pxOtherTCB;
+        pxOtherTCB = xUnconstrainedTCB();
+
+        if( pxOtherTCB != NULL )
+        {
+            vListInsert( &pxReadyTasksLists[ pxOtherTCB->uxPriority ], &( pxOtherTCB->xStateListItem ) );
+        }
+    }
+
+    if( pxTCB != NULL )
+    {
+        /* Needed for coverage: nondeterministic insertion of task */
+        if( nondet_bool() )
+        {
+            vListInsert( &pxReadyTasksLists[ pxTCB->uxPriority ], &( pxTCB->xStateListItem ) );
+        }
+    }
+
+    /* Note that `*xTask = NULL` can happen here, but this is fine -- `pxCurrentTCB` will be used instead */
+    *xTask = pxTCB;
+
+    pxCurrentTCB = xUnconstrainedTCB();
+
+    if( pxCurrentTCB == NULL )
+    {
+        return pdFAIL;
+    }
+
+    /* Needed for coverage: nondeterministic insertion of task */
+    if( nondet_bool() )
+    {
+        vListInsert( &pxReadyTasksLists[ pxCurrentTCB->uxPriority ], &( pxCurrentTCB->xStateListItem ) );
+
+        /* Needed for coverage. */
+        listGET_OWNER_OF_NEXT_ENTRY( pxCurrentTCB, &pxReadyTasksLists[ pxCurrentTCB->uxPriority ] );
+    }
+
+    return pdPASS;
+}

kernel/FreeRTOS/Test/CBMC/proofs/Task/TaskResumeAll/Configurations.json

@@ -0,0 +1,69 @@
+#
+# 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": "TaskResumeAll",
+  "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"
+      ]
+    },
+    { "useTickHook1":
+      [
+        "FREERTOS_MODULE_TEST",
+        "PENDED_TICKS=1",
+        "'mtCOVERAGE_TEST_MARKER()=__CPROVER_assert(1, \"Coverage marker\")'",
+        "configUSE_TRACE_FACILITY=0",
+        "configGENERATE_RUN_TIME_STATS=0",
+        "configUSE_TICK_HOOK=1"
+      ]
+    }
+  ],
+  "CBMCFLAGS":
+  [
+    "--unwind 1",
+    "--unwindset prvInitialiseTaskLists.0:8,xTaskResumeAll.0:2,vListInsert.0:5,xTaskIncrementTick.0:4"
+
+  ],
+  "OBJS":
+  [
+    "$(ENTRY)_harness.goto",
+    "$(FREERTOS)/Source/tasks.goto",
+    "$(FREERTOS)/Source/list.goto"
+  ],
+  "INC":
+  [
+    "$(FREERTOS)/Test/CBMC/proofs/Task/TaskResumeAll/"
+  ]
+}

kernel/FreeRTOS/Test/CBMC/proofs/Task/TaskResumeAll/README.md

@@ -0,0 +1,19 @@
+This proof demonstrates the memory safety of the TaskResumeAll function.  We
+assume that task lists are initialized and filled with a few list items. We
+also assume that some global variables are set to a nondeterministic value,
+except for `uxSchedulerSuspended` which cannot be 0 and `xPendedTicks` which
+is either `1` (to unwind a loop in a reasonable amount of time) or `0`.
+
+Configurations available:
+ * `default`: The default configuration.
+ * `useTickHook1`: The default configuration with `configUSE_TICK_HOOK=1`
+
+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:
+
+* vApplicationTickHook
+* vPortEnterCritical
+* vPortExitCritical
+* vPortGenerateSimulatedInterrupt

kernel/FreeRTOS/Test/CBMC/proofs/Task/TaskResumeAll/TaskResumeAll_harness.c

@@ -0,0 +1,53 @@
+/*
+ * 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.
+ *
+ * https://aws.amazon.com/freertos
+ * https://www.FreeRTOS.org
+ */
+
+#include <stdint.h>
+
+/* FreeRTOS includes. */
+#include "FreeRTOS.h"
+#include "task.h"
+
+void vSetGlobalVariables( void );
+BaseType_t xPrepareTaskLists( void );
+
+/*
+ * The harness test first calls two functions included in the tasks.c file
+ * that initialize the task lists and other global variables
+ */
+void harness()
+{
+    BaseType_t xTasksPrepared;
+
+    vSetGlobalVariables();
+    xTasksPrepared = xPrepareTaskLists();
+
+    if( xTasksPrepared != pdFAIL )
+    {
+        xTaskResumeAll();
+    }
+}

kernel/FreeRTOS/Test/CBMC/proofs/Task/TaskResumeAll/cbmc-viewer.json

@@ -0,0 +1,28 @@
+{ "expected-missing-functions":
+  [
+    "vApplicationTickHook",
+
+    "pxPortInitialiseStack",
+    "vPortCloseRunningThread",
+    "vPortDeleteThread",
+    "vPortEnterCritical",
+    "vPortExitCritical",
+    "vPortGenerateSimulatedInterrupt",
+    "xPortStartScheduler",
+
+    "pvTaskIncrementMutexHeldCount",
+    "uxTaskGetTaskNumber",
+    "vTaskInternalSetTimeOutState",
+    "vTaskMissedYield",
+    "vTaskPlaceOnEventList",
+    "vTaskPriorityDisinheritAfterTimeout",
+    "vTaskSuspendAll",
+    "xTaskGetCurrentTaskHandle",
+    "xTaskPriorityDisinherit",
+    "xTaskPriorityInherit",
+    "xTaskRemoveFromEventList",
+    "xTaskResumeAll"
+  ],
+  "proof-name": "TaskResumeAll",
+  "proof-root": "Test/CBMC/proofs"
+}

kernel/FreeRTOS/Test/CBMC/proofs/Task/TaskResumeAll/tasks_test_access_functions.h

@@ -0,0 +1,150 @@
+/*
+ * 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.
+ *
+ * https://aws.amazon.com/freertos
+ * https://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 xPendedTicks since __CPROVER_assume does not work
+ * well with statically initialised variables
+ */
+void vSetGlobalVariables( void )
+{
+    UBaseType_t uxNonZeroValue;
+
+    __CPROVER_assume( uxNonZeroValue != 0 );
+
+    uxSchedulerSuspended = uxNonZeroValue;
+    xPendedTicks = nondet_bool() ? PENDED_TICKS : 0;
+    uxCurrentNumberOfTasks = nondet_ubasetype();
+    xTickCount = 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();
+
+    /* This task will be moved to a ready list, granting coverage
+     * on lines 2780-2786 (tasks.c) */
+    pxTCB = xUnconstrainedTCB();
+
+    if( pxTCB == NULL )
+    {
+        return pdFAIL;
+    }
+
+    vListInsert( pxOverflowDelayedTaskList, &( pxTCB->xStateListItem ) );
+
+    /* Use of this macro ensures coverage on line 185 (list.c) */
+    listGET_OWNER_OF_NEXT_ENTRY( pxTCB, pxOverflowDelayedTaskList );
+
+    pxTCB = xUnconstrainedTCB();
+
+    if( pxTCB == NULL )
+    {
+        return pdFAIL;
+    }
+
+    vListInsert( &xPendingReadyList, &( pxTCB->xStateListItem ) );
+    vListInsert( pxOverflowDelayedTaskList, &( pxTCB->xEventListItem ) );
+
+    pxTCB = xUnconstrainedTCB();
+
+    if( pxTCB == NULL )
+    {
+        return pdFAIL;
+    }
+
+    vListInsert( pxOverflowDelayedTaskList, &( pxTCB->xStateListItem ) );
+
+    /* This nondeterministic choice ensure coverage in line 2746 (tasks.c) */
+    if( nondet_bool() )
+    {
+        vListInsert( pxOverflowDelayedTaskList, &( pxTCB->xEventListItem ) );
+    }
+
+    pxCurrentTCB = xUnconstrainedTCB();
+
+    if( pxCurrentTCB == NULL )
+    {
+        return pdFAIL;
+    }
+
+    vListInsert( &pxReadyTasksLists[ pxCurrentTCB->uxPriority ], &( pxCurrentTCB->xStateListItem ) );
+
+    return pdPASS;
+}

kernel/FreeRTOS/Test/CBMC/proofs/Task/TaskSetTimeOutState/Makefile.json

@@ -0,0 +1,48 @@
+#
+# 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": "TaskSetTimeOutState",
+  "DEF":
+  [
+    "'mtCOVERAGE_TEST_MARKER()=__CPROVER_assert(1, \"Coverage marker\")'"
+  ],
+  "CBMCFLAGS":
+  [
+      "--unwind 1"
+  ],
+  "OBJS":
+  [
+    "$(ENTRY)_harness.goto",
+    "$(FREERTOS)/Source/tasks.goto"
+  ],
+  "INC":
+  [
+    "$(FREERTOS)/Test/CBMC/proofs/Task/TaskSetTimeOutState/"
+  ]
+}

kernel/FreeRTOS/Test/CBMC/proofs/Task/TaskSetTimeOutState/README.md

@@ -0,0 +1,10 @@
+This proof demonstrates the memory safety of the TaskSetTimeOutState function.
+No assumption is required other than its single argument being non-NULL.
+
+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

kernel/FreeRTOS/Test/CBMC/proofs/Task/TaskSetTimeOutState/TaskSetTimeOutState_harness.c

@@ -0,0 +1,44 @@
+/*
+ * 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.
+ *
+ * https://aws.amazon.com/freertos
+ * https://www.FreeRTOS.org
+ */
+
+#include <stdint.h>
+
+/* FreeRTOS includes. */
+#include "FreeRTOS.h"
+#include "task.h"
+
+/*
+ * We assume xTime to allocated since the function includes a configASSERT
+ * call at the beginning to make sure the pointer to it is not NULL
+ */
+void harness()
+{
+    TimeOut_t xTime;
+
+    vTaskSetTimeOutState( &xTime );
+}

kernel/FreeRTOS/Test/CBMC/proofs/Task/TaskSetTimeOutState/cbmc-viewer.json

@@ -0,0 +1,28 @@
+{ "expected-missing-functions":
+  [
+    "vApplicationTickHook",
+
+    "pxPortInitialiseStack",
+    "vPortCloseRunningThread",
+    "vPortDeleteThread",
+    "vPortEnterCritical",
+    "vPortExitCritical",
+    "vPortGenerateSimulatedInterrupt",
+    "xPortStartScheduler",
+
+    "pvTaskIncrementMutexHeldCount",
+    "uxTaskGetTaskNumber",
+    "vTaskInternalSetTimeOutState",
+    "vTaskMissedYield",
+    "vTaskPlaceOnEventList",
+    "vTaskPriorityDisinheritAfterTimeout",
+    "vTaskSuspendAll",
+    "xTaskGetCurrentTaskHandle",
+    "xTaskPriorityDisinherit",
+    "xTaskPriorityInherit",
+    "xTaskRemoveFromEventList",
+    "xTaskResumeAll"
+  ],
+  "proof-name": "TaskSetTimeOutState",
+  "proof-root": "Test/CBMC/proofs"
+}

kernel/FreeRTOS/Test/CBMC/proofs/Task/TaskStartScheduler/Makefile.json

@@ -0,0 +1,55 @@
+#
+# 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": "TaskStartScheduler",
+  "DEF":
+  [
+    "FREERTOS_MODULE_TEST",
+    "'mtCOVERAGE_TEST_MARKER()=__CPROVER_assert(1, \"Coverage marker\")'",
+    "configUSE_TRACE_FACILITY=0",
+    "configGENERATE_RUN_TIME_STATS=0"
+  ],
+  "CBMCFLAGS":
+  [
+      "--unwind 1",
+      "--unwindset prvInitialiseTaskLists.0:8,prvInitialiseNewTask.0:16,prvInitialiseNewTask.1:4"
+  ],
+  "OBJS":
+  [
+    "$(ENTRY)_harness.goto",
+    "$(FREERTOS)/Source/tasks.goto",
+    "$(FREERTOS)/Source/list.goto",
+    "$(FREERTOS)/Source/timers.goto",
+    "$(FREERTOS)/Source/queue.goto"
+  ],
+  "INC":
+  [
+    "$(FREERTOS)/Test/CBMC/proofs/Task/TaskStartScheduler/"
+  ]
+}

kernel/FreeRTOS/Test/CBMC/proofs/Task/TaskStartScheduler/README.md

@@ -0,0 +1,18 @@
+This proof demonstrates the memory safety of the TaskStartScheduler function.
+We assume that buffers for `pxIdleTaskTCB` and `pxTimerTaskTCB` (and their
+associated stacks `pxIdleTaskStack` and `pxTimerTaskStack`) have been
+previously allocated. The arguments passed by reference to
+`vApplicationGetIdleTaskMemory` and `vApplicationGetTimerTaskMemory` are
+assigned to these pointers since both functions expect statically-allocated
+buffers to be passed.
+
+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:
+
+* pxPortInitialiseStack
+* vConfigureTimerForRunTimeStats
+* vPortEnterCritical
+* vPortExitCritical
+* xPortStartScheduler

kernel/FreeRTOS/Test/CBMC/proofs/Task/TaskStartScheduler/TaskStartScheduler_harness.c

@@ -0,0 +1,51 @@
+/*
+ * 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.
+ *
+ * https://aws.amazon.com/freertos
+ * https://www.FreeRTOS.org
+ */
+
+#include <stdint.h>
+
+/* FreeRTOS includes. */
+#include "FreeRTOS.h"
+#include "task.h"
+
+BaseType_t xPrepareTasks( void );
+
+/*
+ * We prepare `pxCurrentTCB` and the idle/timer task buffers
+ * (TCB + stack), then we call the function if allocation was ok
+ */
+void harness()
+{
+    BaseType_t xTasksPrepared;
+
+    xTasksPrepared = xPrepareTasks();
+
+    if( xTasksPrepared != pdFAIL )
+    {
+        vTaskStartScheduler();
+    }
+}

kernel/FreeRTOS/Test/CBMC/proofs/Task/TaskStartScheduler/cbmc-viewer.json

@@ -0,0 +1,28 @@
+{ "expected-missing-functions":
+  [
+    "vApplicationTickHook",
+
+    "pxPortInitialiseStack",
+    "vPortCloseRunningThread",
+    "vPortDeleteThread",
+    "vPortEnterCritical",
+    "vPortExitCritical",
+    "vPortGenerateSimulatedInterrupt",
+    "xPortStartScheduler",
+
+    "pvTaskIncrementMutexHeldCount",
+    "uxTaskGetTaskNumber",
+    "vTaskInternalSetTimeOutState",
+    "vTaskMissedYield",
+    "vTaskPlaceOnEventList",
+    "vTaskPriorityDisinheritAfterTimeout",
+    "vTaskSuspendAll",
+    "xTaskGetCurrentTaskHandle",
+    "xTaskPriorityDisinherit",
+    "xTaskPriorityInherit",
+    "xTaskRemoveFromEventList",
+    "xTaskResumeAll"
+  ],
+  "proof-name": "TaskStartScheduler",
+  "proof-root": "Test/CBMC/proofs"
+}

kernel/FreeRTOS/Test/CBMC/proofs/Task/TaskStartScheduler/tasks_test_access_functions.h

@@ -0,0 +1,120 @@
+/*
+ * FreeRTOS V202212.01
+ * Copyright (C) 2020 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.
+ *
+ * https://www.FreeRTOS.org
+ * https://github.com/FreeRTOS
+ *
+ */
+
+/*
+ * FreeRTOS memory safety proofs with CBMC.
+ */
+
+#include "cbmc.h"
+
+/*
+ * We allocate an unconstrained TCB or return NULL if it fails
+ */
+TaskHandle_t xUnconstrainedTCB( void )
+{
+    TCB_t * pxTCB = pvPortMalloc( sizeof( TCB_t ) );
+
+    if( pxTCB == NULL )
+    {
+        return NULL;
+    }
+
+    return pxTCB;
+}
+
+StaticTask_t * pxIdleTaskTCB;
+StaticTask_t * pxTimerTaskTCB;
+StackType_t * pxIdleTaskStack;
+StackType_t * pxTimerTaskStack;
+
+/*
+ * `pxCurrentTCB` allocation is allowed to fail. The global variables above
+ * this comment are used in the stubbed functions `vApplicationGetIdleTaskMemory`
+ * and `vApplicationGetTimerTaskMemory` (at the end of this file) and buffer allocation
+ * must be successful for the proof to have no errors
+ */
+BaseType_t xPrepareTasks( void )
+{
+    __CPROVER_assert_zero_allocation();
+
+    prvInitialiseTaskLists();
+
+    pxCurrentTCB = xUnconstrainedTCB();
+
+    pxIdleTaskTCB = pvPortMalloc( sizeof( StaticTask_t ) );
+
+    if( pxIdleTaskTCB == NULL )
+    {
+        return pdFAIL;
+    }
+
+    pxIdleTaskStack = pvPortMalloc( sizeof( StackType_t ) * configMINIMAL_STACK_SIZE );
+
+    if( pxIdleTaskStack == NULL )
+    {
+        return pdFAIL;
+    }
+
+    pxTimerTaskTCB = pvPortMalloc( sizeof( StaticTask_t ) );
+
+    if( pxTimerTaskTCB == NULL )
+    {
+        return pdFAIL;
+    }
+
+    pxTimerTaskStack = pvPortMalloc( sizeof( StackType_t ) * configTIMER_TASK_STACK_DEPTH );
+
+    if( pxTimerTaskStack == NULL )
+    {
+        return pdFAIL;
+    }
+
+    return pdPASS;
+}
+
+/*
+ * The buffers used here have been successfully allocated before (global variables)
+ */
+void vApplicationGetIdleTaskMemory( StaticTask_t ** ppxIdleTaskTCBBuffer,
+                                    StackType_t ** ppxIdleTaskStackBuffer,
+                                    uint32_t * pulIdleTaskStackSize )
+{
+    *ppxIdleTaskTCBBuffer = pxIdleTaskTCB;
+    *ppxIdleTaskStackBuffer = pxIdleTaskStack;
+    *pulIdleTaskStackSize = configMINIMAL_STACK_SIZE;
+}
+
+/*
+ * The buffers used here have been successfully allocated before (global variables)
+ */
+void vApplicationGetTimerTaskMemory( StaticTask_t ** ppxTimerTaskTCBBuffer,
+                                     StackType_t ** ppxTimerTaskStackBuffer,
+                                     uint32_t * pulTimerTaskStackSize )
+{
+    *ppxTimerTaskTCBBuffer = pxTimerTaskTCB;
+    *ppxTimerTaskStackBuffer = pxTimerTaskStack;
+    *pulTimerTaskStackSize = configTIMER_TASK_STACK_DEPTH;
+}

kernel/FreeRTOS/Test/CBMC/proofs/Task/TaskSuspendAll/Makefile.json

@@ -0,0 +1,49 @@
+#
+# 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": "TaskSuspendAll",
+  "DEF":
+  [
+    "'mtCOVERAGE_TEST_MARKER()=__CPROVER_assert(1, \"Coverage marker\")'"
+  ],
+  "CBMCFLAGS":
+  [
+      "--unwind 1"
+  ],
+  "OBJS":
+  [
+    "$(ENTRY)_harness.goto",
+    "$(FREERTOS)/Source/tasks.goto",
+    "$(FREERTOS)/Source/list.goto"
+  ],
+  "INC":
+  [
+    "$(FREERTOS)/Test/CBMC/proofs/Task/TaskSuspendAll/"
+  ]
+}

kernel/FreeRTOS/Test/CBMC/proofs/Task/TaskSuspendAll/README.md

@@ -0,0 +1,5 @@
+This proof demonstrates the memory safety of the TaskSuspendAll function.
+No assumption or abstraction is required for this memory-safety proof.
+
+This proof is a work-in-progress.  Proof assumptions are described in
+the harness.

kernel/FreeRTOS/Test/CBMC/proofs/Task/TaskSuspendAll/TaskSuspendAll_harness.c

@@ -0,0 +1,42 @@
+/*
+ * 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.
+ *
+ * https://aws.amazon.com/freertos
+ * https://www.FreeRTOS.org
+ */
+
+#include <stdint.h>
+
+/* FreeRTOS includes. */
+#include "FreeRTOS.h"
+#include "task.h"
+
+/*
+ * We just call vTaskSuspendAll(). No assumption
+ * or abstraction is required for this proof
+ */
+void harness()
+{
+    vTaskSuspendAll();
+}

kernel/FreeRTOS/Test/CBMC/proofs/Task/TaskSuspendAll/cbmc-viewer.json

@@ -0,0 +1,28 @@
+{ "expected-missing-functions":
+  [
+    "vApplicationTickHook",
+
+    "pxPortInitialiseStack",
+    "vPortCloseRunningThread",
+    "vPortDeleteThread",
+    "vPortEnterCritical",
+    "vPortExitCritical",
+    "vPortGenerateSimulatedInterrupt",
+    "xPortStartScheduler",
+
+    "pvTaskIncrementMutexHeldCount",
+    "uxTaskGetTaskNumber",
+    "vTaskInternalSetTimeOutState",
+    "vTaskMissedYield",
+    "vTaskPlaceOnEventList",
+    "vTaskPriorityDisinheritAfterTimeout",
+    "vTaskSuspendAll",
+    "xTaskGetCurrentTaskHandle",
+    "xTaskPriorityDisinherit",
+    "xTaskPriorityInherit",
+    "xTaskRemoveFromEventList",
+    "xTaskResumeAll"
+  ],
+  "proof-name": "TaskSuspendAll",
+  "proof-root": "Test/CBMC/proofs"
+}

kernel/FreeRTOS/Test/CBMC/proofs/Task/TaskSwitchContext/Makefile.json

@@ -0,0 +1,52 @@
+#
+# 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": "TaskSwitchContext",
+  "DEF":
+  [
+    "FREERTOS_MODULE_TEST",
+    "'portGET_HIGHEST_PRIORITY(uxTopPriority, uxReadyPriorities)=__CPROVER_assume( uxTopPriority < configMAX_PRIORITIES )'",
+    "'mtCOVERAGE_TEST_MARKER()=__CPROVER_assert(1, \"Coverage marker\")'"
+  ],
+  "CBMCFLAGS":
+  [
+      "--unwind 1",
+      "--unwindset prvInitialiseTaskLists.0:8,xPrepareTaskLists.0:8,vListInsert.0:2"
+  ],
+  "OBJS":
+  [
+    "$(ENTRY)_harness.goto",
+    "$(FREERTOS)/Source/tasks.goto",
+    "$(FREERTOS)/Source/list.goto"
+  ],
+  "INC":
+  [
+    "$(FREERTOS)/Test/CBMC/proofs/Task/TaskSwitchContext/"
+  ]
+}

kernel/FreeRTOS/Test/CBMC/proofs/Task/TaskSwitchContext/README.md

@@ -0,0 +1,14 @@
+This proof demonstrates the memory safety of the TaskSwitchContext function.
+We assume task ready lists to be initialized and filled with one element each,
+and `pxCurrentTCB` to be the highest priority task.  We also set
+`uxSchedulerSuspended` to a nondeterministic value.
+
+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:
+
+* prvTraceGetCurrentTaskHandle
+* prvTraceGetTaskNumber
+* prvTraceStoreTaskswitch
+* ulGetRunTimeCounterValue

kernel/FreeRTOS/Test/CBMC/proofs/Task/TaskSwitchContext/TaskSwitchContext_harness.c

@@ -0,0 +1,54 @@
+/*
+ * 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.
+ *
+ * https://aws.amazon.com/freertos
+ * https://www.FreeRTOS.org
+ */
+
+#include <stdint.h>
+
+/* FreeRTOS includes. */
+#include "FreeRTOS.h"
+#include "task.h"
+
+void vSetGlobalVariables( void );
+BaseType_t xPrepareTaskLists( void );
+
+/*
+ * We prepare task lists by inserting one item in each list,
+ * and with the macro redefinition we ensure only valid ready
+ * task lists are checked in `taskSELECT_HIGHEST_PRIORITY_TASK()`
+ */
+void harness()
+{
+    BaseType_t xTasksPrepared;
+
+    vSetGlobalVariables();
+    xTasksPrepared = xPrepareTaskLists();
+
+    if( xTasksPrepared != pdFAIL )
+    {
+        vTaskSwitchContext();
+    }
+}

kernel/FreeRTOS/Test/CBMC/proofs/Task/TaskSwitchContext/cbmc-viewer.json

@@ -0,0 +1,28 @@
+{ "expected-missing-functions":
+  [
+    "vApplicationTickHook",
+
+    "pxPortInitialiseStack",
+    "vPortCloseRunningThread",
+    "vPortDeleteThread",
+    "vPortEnterCritical",
+    "vPortExitCritical",
+    "vPortGenerateSimulatedInterrupt",
+    "xPortStartScheduler",
+
+    "pvTaskIncrementMutexHeldCount",
+    "uxTaskGetTaskNumber",
+    "vTaskInternalSetTimeOutState",
+    "vTaskMissedYield",
+    "vTaskPlaceOnEventList",
+    "vTaskPriorityDisinheritAfterTimeout",
+    "vTaskSuspendAll",
+    "xTaskGetCurrentTaskHandle",
+    "xTaskPriorityDisinherit",
+    "xTaskPriorityInherit",
+    "xTaskRemoveFromEventList",
+    "xTaskResumeAll"
+  ],
+  "proof-name": "TaskSwitchContext",
+  "proof-root": "Test/CBMC/proofs"
+}

kernel/FreeRTOS/Test/CBMC/proofs/Task/TaskSwitchContext/tasks_test_access_functions.h

@@ -0,0 +1,109 @@
+/*
+ * 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.
+ *
+ * https://aws.amazon.com/freertos
+ * https://www.FreeRTOS.org
+ */
+
+#include "cbmc.h"
+
+/*
+ * We allocate a TCB and set some members to basic values
+ */
+TaskHandle_t xUnconstrainedTCB( UBaseType_t uxPriority )
+{
+    TCB_t * pxTCB = pvPortMalloc( sizeof( TCB_t ) );
+
+    if( pxTCB == NULL )
+    {
+        return NULL;
+    }
+
+    /* uxPriority is set to a specific priority */
+    pxTCB->uxPriority = uxPriority;
+
+    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
+ */
+void vSetGlobalVariables( void )
+{
+    uxSchedulerSuspended = nondet_ubasetype();
+}
+
+/*
+ * We initialize and fill with one item each ready tasks list
+ * so that the assertion on line 175 (tasks.c) does not fail
+ */
+BaseType_t xPrepareTaskLists( void )
+{
+    TCB_t * pxTCB = NULL;
+
+    __CPROVER_assert_zero_allocation();
+
+    prvInitialiseTaskLists();
+
+    for( int i = 0; i < configMAX_PRIORITIES; ++i )
+    {
+        pxTCB = xUnconstrainedTCB( i );
+
+        if( pxTCB == NULL )
+        {
+            return pdFAIL;
+        }
+
+        vListInsert( &pxReadyTasksLists[ pxTCB->uxPriority ], &( pxTCB->xStateListItem ) );
+    }
+
+    listGET_OWNER_OF_NEXT_ENTRY( pxCurrentTCB, &pxReadyTasksLists[ configMAX_PRIORITIES - 1 ] );
+
+    return pdPASS;
+}