513 struct stackid {  struct
523 static int stackid_init(struct stackid *stackid, struct bpf_map *map,  in stackid_init()  argument
535 	stackid->nr = min_t(u32, trace_nr - skip, max_depth - skip);  in stackid_init()
536 	stackid->len = stackid->nr * sizeof(u64);  in stackid_init()
537 	stackid->ips = trace->ip + skip;  in stackid_init()
538 	stackid->hash = jhash2((const u32 *)stackid->ips, stackid->len / sizeof(u32), 0);  in stackid_init()
539 	stackid->id = stackid->hash & (smap->n_buckets - 1);  in stackid_init()
540 	stackid->bucket = READ_ONCE(smap->buckets[stackid->id]);  in stackid_init()
541 	stackid->hash_matches = stackid->bucket && stackid->bucket->hash == stackid->hash;  in stackid_init()
545 static int stackid_fastpath(struct stackid *stackid, struct bpf_map *map,  in stackid_fastpath()  argument
551 	err = stackid_init(stackid, map, trace, trace_nr, flags);  in stackid_fastpath()
556 	if (stackid->hash_matches && flags & BPF_F_FAST_STACK_CMP)  in stackid_fastpath()
557 		return stackid->id;  in stackid_fastpath()
561 	if (stackid->hash_matches && stackid->bucket->nr == stackid->nr &&  in stackid_fastpath()
562 	    memcmp(stackid->bucket->data, stackid->ips, stackid->len) == 0)  in stackid_fastpath()
563 		return stackid->id;  in stackid_fastpath()
564 	if (stackid->bucket && !(flags & BPF_F_REUSE_STACKID))  in stackid_fastpath()
570 stackid_new_bucket(struct stackid *stackid, struct bpf_map *map)  in stackid_new_bucket()  argument
583 		for (i = 0; i < stackid->nr; i++)  in stackid_new_bucket()
584 			id_offs[i].ip = stackid->ips[i];  in stackid_new_bucket()
586 		memcpy(bucket->data, stackid->ips, stackid->len);  in stackid_new_bucket()
589 	bucket->hash = stackid->hash;  in stackid_new_bucket()
590 	bucket->nr = stackid->nr;  in stackid_new_bucket()
594 static long stackid_install(struct stackid *stackid, struct bpf_map *map,  in stackid_install()  argument
606 		stack_map_get_build_id_offset(id_offs, stackid->nr, user, false /* !may_fault */);  in stackid_install()
607 		trace_len = stackid->nr * sizeof(struct bpf_stack_build_id);  in stackid_install()
608 		if (stackid->hash_matches && stackid->bucket->nr == stackid->nr &&  in stackid_install()
609 		    memcmp(stackid->bucket->data, new_bucket->data, trace_len) == 0) {  in stackid_install()
611 			return stackid->id;  in stackid_install()
613 		if (stackid->bucket && !(flags & BPF_F_REUSE_STACKID)) {  in stackid_install()
619 	old_bucket = xchg(&smap->buckets[stackid->id], new_bucket);  in stackid_install()
622 	return stackid->id;  in stackid_install()
632 	struct stackid stackid;  in BPF_CALL_3()  local
650 		err = stackid_fastpath(&stackid, map, trace, trace->nr, flags);  in BPF_CALL_3()
654 		new_bucket = stackid_new_bucket(&stackid, map);  in BPF_CALL_3()
659 	return stackid_install(&stackid, map, new_bucket, flags);  in BPF_CALL_3()
689 	struct stackid stackid;  in BPF_CALL_3()  local
726 	ret = stackid_fastpath(&stackid, map, trace, trace_nr, flags);  in BPF_CALL_3()
730 	new_bucket = stackid_new_bucket(&stackid, map);  in BPF_CALL_3()
732 		return stackid_install(&stackid, map, new_bucket, flags);  in BPF_CALL_3()