Hello pengdonglin,
Commit f83ac7544fbf ("function_graph: Enable funcgraph-args and
funcgraph-retaddr to work simultaneously") from Nov 25, 2025
(linux-next), leads to the following Smatch static checker warning:
kernel/trace/trace_functions_graph.c:1033 print_graph_entry_nested() warn:
unsigned 'call->depth' is never less than zero.
kernel/trace/trace_functions_graph.c:975 print_graph_entry_leaf() warn:
unsigned 'call->depth' is never less than zero.
kernel/trace/trace.h:1130 ftrace_graph_ignore_func() warn: unsigned
'trace->depth' is never less than zero.
kernel/trace/trace_functions_graph.c
1012 static enum print_line_t
1013 print_graph_entry_nested(struct trace_iterator *iter,
1014 struct ftrace_graph_ent_entry *entry,
1015 struct trace_seq *s, int cpu, u32 flags)
1016 {
1017 struct ftrace_graph_ent *call = &entry->graph_ent;
1018 struct fgraph_data *data = iter->private;
1019 struct trace_array *tr = iter->tr;
1020 unsigned long func;
1021 int args_size;
1022 int i;
1023
1024 if (data) {
1025 struct fgraph_cpu_data *cpu_data;
1026 int cpu = iter->cpu;
1027
1028 cpu_data = per_cpu_ptr(data->cpu_data, cpu);
1029 cpu_data->depth = call->depth;
1030
1031 /* Save this function pointer to see if the exit
matches */
1032 if (call->depth < FTRACE_RETFUNC_DEPTH &&
--> 1033 !WARN_ON_ONCE(call->depth < 0))
^^^^^^^^^^^^^^^
The patch changed call->depth from int to unsigned long.
1034 cpu_data->enter_funcs[call->depth] =
call->func;
1035 }
1036
1037 /* No time */
1038 print_graph_duration(tr, 0, s, flags | FLAGS_FILL_FULL);
regards,
dan carpenter
