osfmk/kern/stack.c

29  *	Kernel stack management routines.
74 static unsigned int		stack_new_count;						/* total new stack allocations */
132  *	The next field is at the base of the stack,
135 #define stack_next(stack)	\
136 	(*((vm_offset_t *)((stack) + kernel_stack_size) - 1))
170 		panic("stack_init: stack size %p not a multiple of page size %d\n",
180  *	Allocate a stack for a thread, may
187 	vm_offset_t		stack;
194 	stack = stack_free_list;
195 	if (stack != 0) {
196 		stack_free_list = stack_next(stack);
208 	if (stack == 0) {
211 		 * Request guard pages on either side of the stack.  Ask
217 		if (kernel_memory_allocate(kernel_map, &stack,
225 		 * The stack address that comes back is the address of the lower
226 		 * guard page.  Skip past it to get the actual stack base address.
229 		stack += PAGE_SIZE;
231 	return stack;
255  *	Detach and free the stack for a thread.
261     vm_offset_t		stack = machine_stack_detach(thread);
263 	assert(stack);
264 	if (stack != thread->reserved_stack) {
266 		stack_free_stack(stack);
282 	vm_offset_t		stack)
290 		stack_next(stack) = cache->free;
291 		cache->free = stack;
296 		stack_next(stack) = stack_free_list;
297 		stack_free_list = stack;
310  *	stack for a thread.
321 	vm_offset_t			stack;
324 	stack = cache->free;
325 	if (stack != 0) {
327 		cache->free = stack_next(stack);
333 			stack = stack_free_list;
334 			if (stack != 0) {
336 				stack_free_list = stack_next(stack);
344 	if (stack != 0 || (stack = thread->reserved_stack) != 0) {
345 		machine_stack_attach(thread, stack);
365 		vm_offset_t		stack;
375 			stack = stack_free_list;
376 			stack_free_list = stack_next(stack);
382 			 * Get the stack base address, then decrement by one page
385 			 * that were originally requested when the stack was allocated
389 			stack = (vm_offset_t)vm_map_trunc_page(stack);
390 			stack -= PAGE_SIZE;
393 				    stack,
394 				    stack + kernel_stack_size+(2*PAGE_SIZE),
398 			stack = 0;
420  *	Limits stack collection to once per
495  * Return info on stack usage for threads in a specific processor set