20  * A function instance keyed by (callsite, depth).
22  * Marks are tracked for each frame up to @depth.
26 	u32 callsite;		/* call insn that invoked this subprog (subprog_start for depth 0) */
27 	u32 depth;		/* call depth (0 = entry subprog) */  member
44 	DECLARE_HASHTABLE(func_instances, 8);		/* maps (depth, callsite) to func_instance */
50  * Hash/compare key for func_instance: (depth, callsite).
51  * For depth == 0 (entry subprog), @callsite is the subprog start insn.
52  * For depth > 0, @callsite is the call instruction index that invoked the subprog.
54 static u32 instance_hash(u32 callsite, u32 depth)  in instance_hash()  argument
56 	u32 key[2] = { depth, callsite };  in instance_hash()
62 					   u32 callsite, u32 depth)  in find_instance()  argument
66 	u32 key = instance_hash(callsite, depth);  in find_instance()
69 		if (f->depth == depth && f->callsite == callsite)  in find_instance()
78 	u32 depth = caller ? caller->depth + 1 : 0;  in call_instance()  local
80 	u32 lookup_key = depth > 0 ? callsite : subprog_start;  in call_instance()
84 	f = find_instance(env, lookup_key, depth);  in call_instance()
92 	f->depth = depth;  in call_instance()
96 	hash = instance_hash(lookup_key, depth);  in call_instance()
107 	u32 key, depth;  in lookup_instance()  local
112 	for (depth = frameno; ; depth--) {  in lookup_instance()
113 		key = depth > 0 ? callsite : subprog_start;  in lookup_instance()
114 		f = find_instance(env, key, depth);  in lookup_instance()
115 		if (f || depth == 0)  in lookup_instance()
138 		for (i = 0; i <= instance->depth; i++)  in bpf_stack_liveness_free()
321 		for (frame = 0; frame <= instance->depth; frame++) {  in update_instance()
377 	cur_delta = (int)curframe_instance->depth - (int)q->curframe;  in bpf_stack_slot_alive()
379 	if (rel <= curframe_instance->depth)  in bpf_stack_slot_alive()
390 		delta = (int)instance->depth - (int)i;  in bpf_stack_slot_alive()
392 		if (rel > instance->depth)  in bpf_stack_slot_alive()
420 		 "(d%d,cs%d)", instance->depth, instance->callsite);  in fmt_instance()
505 		for (frame = instance->depth; frame >= 0; --frame) {  in print_instance()
516 		for (frame = instance->depth; frame >= 0; --frame) {  in print_instance()
536 	int ddepth = (int)a->depth - b->depth;  in cmp_instances()
545 /* print use/def slots for all instances ordered by callsite first, then by depth */
885 					int depth)  in fill_from_stack()  argument
888 		.mask = (1u << (depth + 1)) - 1,  in fill_from_stack()
1051 static bool can_be_local_fp(int depth, int regno, struct arg_track *at)  in can_be_local_fp()  argument
1053 	return regno == BPF_REG_FP || at->frame == depth ||  in can_be_local_fp()
1054 	       (at->frame == ARG_IMPRECISE && (at->mask & BIT(depth)));  in can_be_local_fp()
1068 	int depth = instance->depth;  in arg_track_xfer()  local
1126 		bool src_is_local_fp = can_be_local_fp(depth, insn->src_reg, src);  in arg_track_xfer()
1135 			*dst = fill_from_stack(insn, at_out, insn->src_reg, at_stack_out, depth);  in arg_track_xfer()
1136 		} else if (src->frame >= 0 && src->frame < depth &&  in arg_track_xfer()
1144 			   !(src->mask & BIT(depth)) && src->mask &&  in arg_track_xfer()
1161 		dst_is_local_fp = can_be_local_fp(depth, insn->dst_reg, dst);  in arg_track_xfer()
1180 		bool dst_is_local_fp = can_be_local_fp(depth, insn->dst_reg, dst);  in arg_track_xfer()
1273 	int depth = instance->depth;  in record_imprecise()  local
1279 		if (f <= depth) {  in record_imprecise()
1294 	int depth = instance->depth;  in record_load_store_access()  local
1338 	if (ptr->frame >= 0 && ptr->frame <= depth)  in record_load_store_access()
1353 	int depth = instance->depth;  in record_call_access()  local
1375 			for (int f = 0; f <= depth; f++) {  in record_call_access()
1385 		if (frame >= 0 && frame <= depth)  in record_call_access()
1540 	int depth = instance->depth;  in compute_subprog_args()  local
1578 	at_in[0][BPF_REG_FP] = arg_single(depth, 0);  in compute_subprog_args()
1591 		verbose(env, "subprog#%d: analyzing (depth %d)...\n", subprog, depth);  in compute_subprog_args()
1696 	for (f = 0; f <= dst->depth; f++) {  in merge_instances()
1731 	f->depth = src->depth;  in fresh_instance()
1742 	for (i = 0; i <= instance->depth; i++)  in free_instance()
1752  * depends on the entry args and frame depth. Consider: A->C->D and B->C->D
1763 	int depth = instance->depth;  in analyze_subprog()  local
1833 				for (int f = 0; f <= depth; f++) {  in analyze_subprog()
1853 		if (depth == MAX_CALL_FRAMES - 1) {  in analyze_subprog()
1863 		callsites[depth] = idx;  in analyze_subprog()
1873 			for (int f = 0; f < callee_instance->depth; f++) {  in analyze_subprog()