3  * Stack depot - a stack trace storage that avoids duplication.
5  * Internally, stack depot maintains a hash table of unique stacktraces. The
6  * stack traces themselves are stored contiguously one after another in a set
47 /* Compact structure that stores a reference to a stack. */
78 /* Hash table of pointers to stored stack traces. */
85 /* Array of memory regions that store stack traces. */
94  * Stack depot tries to keep an extra pool allocated even before it runs out
136 	 * stack traces being stored in stack depot.  in stack_depot_early_init()
221 /* Uses preallocated memory to initialize a new stack depot pool. */
258 /* Allocates a new stack in a stack depot pool. */
262 	struct stack_record *stack;  in depot_alloc_stack()  local
263 	size_t required_size = struct_size(stack, entries, size);  in depot_alloc_stack()
271 			WARN_ONCE(1, "Stack depot reached limit capacity");  in depot_alloc_stack()
296 	/* Check if we have a pool to save the stack trace. */  in depot_alloc_stack()
300 	/* Save the stack trace. */  in depot_alloc_stack()
301 	stack = stack_pools[pool_index] + pool_offset;  in depot_alloc_stack()
302 	stack->hash = hash;  in depot_alloc_stack()
303 	stack->size = size;  in depot_alloc_stack()
304 	stack->handle.pool_index = pool_index;  in depot_alloc_stack()
305 	stack->handle.offset = pool_offset >> DEPOT_STACK_ALIGN;  in depot_alloc_stack()
306 	stack->handle.valid = 1;  in depot_alloc_stack()
307 	stack->handle.extra = 0;  in depot_alloc_stack()
308 	memcpy(stack->entries, entries, flex_array_size(stack, entries, size));  in depot_alloc_stack()
311 	 * Let KMSAN know the stored stack record is initialized. This shall  in depot_alloc_stack()
314 	kmsan_unpoison_memory(stack, required_size);  in depot_alloc_stack()
316 	return stack;  in depot_alloc_stack()
319 /* Calculates the hash for a stack. */
342 /* Finds a stack in a bucket of the hash table. */
370 	 * If this stack trace is from an interrupt, including anything before  in __stack_depot_save()
371 	 * interrupt entry usually leads to unbounded stack depot growth.  in __stack_depot_save()
373 	 * Since use of filter_irq_stacks() is a requirement to ensure stack  in __stack_depot_save()
375 	 * filter_irq_stacks() to simplify all callers' use of stack depot.  in __stack_depot_save()
386 	 * Fast path: look the stack trace up without locking.  in __stack_depot_save()
395 	 * Check if another stack pool needs to be initialized. If so, allocate  in __stack_depot_save()
433 		 * Stack depot already contains this stack trace, but let's  in __stack_depot_save()
442 		/* Stack depot didn't use this memory, free it. */  in __stack_depot_save()
471 	struct stack_record *stack;  in stack_depot_fetch()  local
484 		WARN(1, "pool index %d out of bounds (%d) for stack id %08x\n",  in stack_depot_fetch()
491 	stack = pool + offset;  in stack_depot_fetch()
493 	*entries = stack->entries;  in stack_depot_fetch()
494 	return stack->size;  in stack_depot_fetch()
498 void stack_depot_print(depot_stack_handle_t stack)  in stack_depot_print()  argument
503 	nr_entries = stack_depot_fetch(stack, &entries);  in stack_depot_print()