From 76fe0337c2199988cb9ed7e41c05d687d95f2e18 Mon Sep 17 00:00:00 2001 From: Sven Schnelle Date: Thu, 27 Feb 2025 13:58:08 -0500 Subject: ftrace: Add arguments to function tracer Wire up the code to print function arguments in the function tracer. This functionality can be enabled/disabled during runtime with options/func-args. ping-689 [004] b.... 77.170220: dummy_xmit(skb = 0x82904800, dev = 0x882d0000) <-dev_hard_start_xmit Cc: Mark Rutland Cc: Mathieu Desnoyers Cc: Andrew Morton Cc: Paul Walmsley Cc: Palmer Dabbelt Cc: Albert Ou Cc: Guo Ren Cc: Donglin Peng Cc: Zheng Yejian Link: https://lore.kernel.org/20250227185823.154996172@goodmis.org Reviewed-by: Masami Hiramatsu (Google) Co-developed-by: Steven Rostedt (Google) Signed-off-by: Sven Schnelle Signed-off-by: Steven Rostedt (Google) --- kernel/trace/trace_output.c | 18 +++++++++++++++--- 1 file changed, 15 insertions(+), 3 deletions(-) (limited to 'kernel/trace/trace_output.c') diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c index 4b721cd4f21d..b51ee9373773 100644 --- a/kernel/trace/trace_output.c +++ b/kernel/trace/trace_output.c @@ -1090,12 +1090,15 @@ enum print_line_t trace_nop_print(struct trace_iterator *iter, int flags, } static void print_fn_trace(struct trace_seq *s, unsigned long ip, - unsigned long parent_ip, long delta, int flags) + unsigned long parent_ip, long delta, + unsigned long *args, int flags) { ip += delta; parent_ip += delta; seq_print_ip_sym(s, ip, flags); + if (args) + print_function_args(s, args, ip); if ((flags & TRACE_ITER_PRINT_PARENT) && parent_ip) { trace_seq_puts(s, " <-"); @@ -1109,10 +1112,19 @@ static enum print_line_t trace_fn_trace(struct trace_iterator *iter, int flags, { struct ftrace_entry *field; struct trace_seq *s = &iter->seq; + unsigned long *args; + int args_size; trace_assign_type(field, iter->ent); - print_fn_trace(s, field->ip, field->parent_ip, iter->tr->text_delta, flags); + args_size = iter->ent_size - offsetof(struct ftrace_entry, args); + if (args_size >= FTRACE_REGS_MAX_ARGS * sizeof(long)) + args = field->args; + else + args = NULL; + + print_fn_trace(s, field->ip, field->parent_ip, iter->tr->text_delta, + args, flags); trace_seq_putc(s, '\n'); return trace_handle_return(s); @@ -1785,7 +1797,7 @@ trace_func_repeats_print(struct trace_iterator *iter, int flags, trace_assign_type(field, iter->ent); - print_fn_trace(s, field->ip, field->parent_ip, iter->tr->text_delta, flags); + print_fn_trace(s, field->ip, field->parent_ip, iter->tr->text_delta, NULL, flags); trace_seq_printf(s, " (repeats: %u, last_ts:", field->count); trace_print_time(s, iter, iter->ts - FUNC_REPEATS_GET_DELTA_TS(field)); -- cgit v1.2.3