Address alignment issue in VxWorks 7 on 32 bit processor

[skliper]

Describe the bug
The task control bock (TCB) has an element with a 64 bit alignment requirement on some processors, but the way the OS_impl_task_internal_record_t is defined for VxWorks 7 does not enforce 64 bit alignment on a 32 bit system. This causes taskInitialize to fail.

Note the use of a char array in the structure here:

osal/src/os/vxworks/inc/os-impl-tasks.h

Lines 32 to 47 in 1de47bb

	#if defined(VX_WIND_TCB_SIZE)
	/* vxworks >= 7.0 should provide this symbol via taskLib.h. WIND_TCB is an opaque type */
	typedef char OS_VxWorks_TCB_t[VX_WIND_TCB_SIZE];
	#else
	/* older vxworks expose the definition of VX_WIND_TCB_SIZE */
	typedef WIND_TCB OS_VxWorks_TCB_t;
	#endif /* !defined(VX_WIND_TCB_SIZE) */
	/*tasks */
	typedef struct
	{
	OS_VxWorks_TCB_t tcb; /* Must be first */
	TASK_ID vxid;
	void * heap_block; /* set non-null if the stack was obtained with malloc() */
	size_t heap_block_size;
	} OS_impl_task_internal_record_t;

Used here:

osal/src/os/vxworks/src/os-impl-tasks.c

Lines 236 to 243 in 1de47bb

	status = taskInit((WIND_TCB *)&lrec->tcb, /* address of new task's TCB */
	(char *)task->task_name, vxpri, /* priority of new task */
	vxflags, /* task option word */
	(char *)actualstackbase, /* base of new task's stack */
	actualsz, /* size (bytes) of stack needed */
	(FUNCPTR)OS_VxWorks_TaskEntry, /* entry point of new task */
	OS_ObjectIdToInteger(OS_ObjectIdFromToken(token)), /* 1st arg is ID */
	0, 0, 0, 0, 0, 0, 0, 0, 0);

To Reproduce
Need to get into a situation where the internal task record (and tcb since it's the first element) is not on a 64 bit boundary, and get's passed into taskInitialize, on a system that errors out if a 64 bit structure element isn't on a boundary. Observed on GR712RC.

Expected behavior
Should initialize tasks successfully. As a quick test a uint64 val; was added to the internal task record, forcing alignment and the task initialization worked.

System observed on:

• Hardware: GR712RC
• OS: VxWorks 7
• Versions: should be observable in Caelum or later

Additional context
None

Reporter Info
Jacob Hageman - NASA/GSFC