3  * Generic stack depot for storing stack traces.
5  * Some debugging tools need to save stack traces of certain events which can
7  * free stacks for each object, but storing two stack traces per object
11  * Instead, stack depot maintains a hashtable of unique stacktraces. Since alloc
38 #define STACK_ALLOC_ORDER 2 /* 'Slab' size order for stack depot, 4 pages */
63 	u32 size;			/* Number of frames in the stack */
103 /* Allocation of a new stack in raw storage */
109 	struct stack_record *stack;  in depot_alloc_stack()  local
115 			WARN_ONCE(1, "Stack depot reached limit capacity");  in depot_alloc_stack()
132 	stack = stack_slabs[depot_index] + depot_offset;  in depot_alloc_stack()
134 	stack->hash = hash;  in depot_alloc_stack()
135 	stack->size = size;  in depot_alloc_stack()
136 	stack->handle.slabindex = depot_index;  in depot_alloc_stack()
137 	stack->handle.offset = depot_offset >> STACK_ALLOC_ALIGN;  in depot_alloc_stack()
138 	stack->handle.valid = 1;  in depot_alloc_stack()
139 	memcpy(stack->entries, entries, size * sizeof(unsigned long));  in depot_alloc_stack()
142 	return stack;  in depot_alloc_stack()
154 /* Calculate hash for a stack */
177 /* Find a stack that is equal to the one stored in entries in the hash */
194  * stack_depot_fetch - Fetch stack entries from a depot
196  * @handle:		Stack depot handle which was returned from
208 	struct stack_record *stack;  in stack_depot_fetch()  local
212 		WARN(1, "slab index %d out of bounds (%d) for stack id %08x\n",  in stack_depot_fetch()
219 	stack = slab + offset;  in stack_depot_fetch()
221 	*entries = stack->entries;  in stack_depot_fetch()
222 	return stack->size;  in stack_depot_fetch()
227  * stack_depot_save - Save a stack trace from an array
233  * Return: The handle of the stack struct stored in depot
253 	 * Fast path: look the stack trace up without locking.  in stack_depot_save()
263 	 * Check if the current or the next stack slab need to be initialized.  in stack_depot_save()
302 		 * We didn't need to store this stack trace, but let's keep  in stack_depot_save()
336 			/* Include the irqentry function into the stack. */  in filter_irq_stacks()