From b04f2b16b2eeabe3b24ed0a7537e9f27acc43f33 Mon Sep 17 00:00:00 2001
From: Joseph Hickey <joseph.p.hickey@nasa.gov>
Date: Wed, 14 Feb 2024 16:33:13 -0500
Subject: [PATCH] Fix #2516, propagate stack pointer for child tasks

Update CFE_ES_CreateChildTask to propagate the user-supplied stack
pointer to the underlying OS_TaskCreate call.  Also adds a functional
test to check that the memory address of a local variable within a
child task resides within the expected stack buffer.

NOTE: this requires an additional fix to POSIX OSAL to make it work
on that platform.
---
 modules/cfe_testcase/src/es_task_test.c | 62 +++++++++++++++++++++++++
 modules/es/fsw/src/cfe_es_api.c         |  1 +
 modules/es/fsw/src/cfe_es_apps.c        |  2 +-
 modules/es/fsw/src/cfe_es_apps.h        |  1 +
 4 files changed, 65 insertions(+), 1 deletion(-)

diff --git a/modules/cfe_testcase/src/es_task_test.c b/modules/cfe_testcase/src/es_task_test.c
index f3ce24171..cad3312f0 100644
--- a/modules/cfe_testcase/src/es_task_test.c
+++ b/modules/cfe_testcase/src/es_task_test.c
@@ -90,6 +90,67 @@ void TaskExitFunction(void)
     }
 }
 
+#define UT_LOCAL_STACK_SIZE 4096
+static unsigned long UT_LOCAL_STACK[UT_LOCAL_STACK_SIZE];
+
+void TestCheckStackPointer(void)
+{
+    int32   LocalVar;
+    cpuaddr VarAddress;
+    cpuaddr StackAddress;
+
+    OS_TaskDelay(10);
+
+    VarAddress   = (cpuaddr)&LocalVar;
+    StackAddress = (cpuaddr)UT_LOCAL_STACK;
+
+    UtAssert_GT(cpuaddr, VarAddress, StackAddress);
+    UtAssert_LT(cpuaddr, VarAddress, StackAddress + sizeof(UT_LOCAL_STACK));
+
+    CFE_ES_ExitChildTask();
+}
+
+void TestCreateChildWithStack(void)
+{
+    CFE_ES_TaskId_t            TaskId        = CFE_ES_TASKID_UNDEFINED;
+    int32                      RetryCount;
+    const char *               TaskName      = "CHILD_W_STACK";
+    CFE_ES_StackPointer_t      StackPointer  = UT_LOCAL_STACK;
+    size_t                     StackSize     = sizeof(UT_LOCAL_STACK);
+    CFE_ES_TaskPriority_Atom_t Priority      = CFE_PLATFORM_ES_PERF_CHILD_PRIORITY;
+    uint32                     Flags         = 0;
+    char                       TaskNameBuf[16];
+
+    UtPrintf("Testing: CFE_ES_CreateChildTask with user-specified stack");
+
+    UtAssert_INT32_EQ(CFE_ES_CreateChildTask(&TaskId, TaskName, TestCheckStackPointer, StackPointer,
+                                             StackSize, Priority, Flags),
+                      CFE_SUCCESS);
+
+    /* wait for task to exit itself */
+    RetryCount = 0;
+    while (RetryCount < 10)
+    {
+        /*
+         * poll until CFE_ES_GetTaskName() returns an error, then the task has exited
+         *
+         * NOTE: this intentionally does not Assert the status here, because the child task is
+         * also doing asserts at the time this loop is running.  Once the child task finishes,
+         * it is OK to do asserts from this task again
+         */
+        if (CFE_Assert_STATUS_STORE(CFE_ES_GetTaskName(TaskNameBuf, TaskId, sizeof(TaskNameBuf))) != CFE_SUCCESS)
+        {
+            break;
+        }
+        OS_TaskDelay(100);
+        ++RetryCount;
+    }
+
+    /* Retroactively confirm that the previous call to CFE_ES_GetTaskName() returned RESOURCEID_NOT_VALID */
+    CFE_Assert_STATUS_MUST_BE(CFE_ES_ERR_RESOURCEID_NOT_VALID);
+}
+
+
 void TestCreateChild(void)
 {
     UtPrintf("Testing: CFE_ES_CreateChildTask");
@@ -292,4 +353,5 @@ void ESTaskTestSetup(void)
     UtTest_Add(TestChildTaskName, NULL, NULL, "Test Child Task Name");
     UtTest_Add(TestChildTaskDelete, NULL, NULL, "Test Child Tasks Delete");
     UtTest_Add(TestExitChild, NULL, NULL, "Test Exit Child");
+    UtTest_Add(TestCreateChildWithStack, NULL, NULL, "Test Child with Custom Stack");
 }
diff --git a/modules/es/fsw/src/cfe_es_api.c b/modules/es/fsw/src/cfe_es_api.c
index 6b460ec6b..b625f520f 100644
--- a/modules/es/fsw/src/cfe_es_api.c
+++ b/modules/es/fsw/src/cfe_es_api.c
@@ -1259,6 +1259,7 @@ CFE_Status_t CFE_ES_CreateChildTask(CFE_ES_TaskId_t *TaskIdPtr, const char *Task
     memset(&Params, 0, sizeof(Params));
     Params.Priority  = Priority;
     Params.StackSize = StackSize;
+    Params.StackPtr  = StackPtr;
 
     /*
     ** Validate some of the arguments
diff --git a/modules/es/fsw/src/cfe_es_apps.c b/modules/es/fsw/src/cfe_es_apps.c
index 56323d24f..ccedf9e05 100644
--- a/modules/es/fsw/src/cfe_es_apps.c
+++ b/modules/es/fsw/src/cfe_es_apps.c
@@ -588,7 +588,7 @@ int32 CFE_ES_StartAppTask(CFE_ES_TaskId_t *TaskIdPtr, const char *TaskName, CFE_
     OsStatus = OS_TaskCreate(&OsalTaskId,              /* task id */
                              TaskName,                 /* task name matches app name for main task */
                              CFE_ES_TaskEntryPoint,    /* task function pointer */
-                             OSAL_TASK_STACK_ALLOCATE, /* stack pointer (allocate) */
+                             Params->StackPtr,         /* stack pointer (allocate if NULL) */
                              Params->StackSize,        /* stack size */
                              Params->Priority,         /* task priority */
                              OS_FP_ENABLED);           /* task options */
diff --git a/modules/es/fsw/src/cfe_es_apps.h b/modules/es/fsw/src/cfe_es_apps.h
index 8a4092eab..8a8c979af 100644
--- a/modules/es/fsw/src/cfe_es_apps.h
+++ b/modules/es/fsw/src/cfe_es_apps.h
@@ -99,6 +99,7 @@ typedef struct
 typedef struct
 {
     size_t                     StackSize;
+    CFE_ES_StackPointer_t      StackPtr;
     CFE_ES_TaskPriority_Atom_t Priority;
 } CFE_ES_TaskStartParams_t;