From a62b4f6fbdffa8e90959da485b68f844241d300f Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (Google)" Date: Wed, 12 Jun 2024 19:19:47 -0400 Subject: tracing: Add last boot delta offset for stack traces The addresses of a stack trace event are relative to the kallsyms. As that can change between boots, when printing the stack trace from a buffer that was from the last boot, it needs all the addresses to be added to the "text_delta" that gives the delta between the addresses of the functions for the current boot compared to the address of the last boot. Then it can be passed to kallsyms to find the function name, otherwise it just shows a useless list of addresses. Link: https://lkml.kernel.org/r/20240612232027.145807384@goodmis.org Cc: Masami Hiramatsu Cc: Mark Rutland Cc: Mathieu Desnoyers Cc: Andrew Morton Cc: Vincent Donnefort Cc: Joel Fernandes Cc: Daniel Bristot de Oliveira Cc: Ingo Molnar Cc: Peter Zijlstra Cc: Thomas Gleixner Cc: Vineeth Pillai Cc: Youssef Esmat Cc: Beau Belgrave Cc: Alexander Graf Cc: Baoquan He Cc: Borislav Petkov Cc: "Paul E. McKenney" Cc: David Howells Cc: Mike Rapoport Cc: Dave Hansen Cc: Tony Luck Cc: Guenter Roeck Cc: Ross Zwisler Cc: Kees Cook Signed-off-by: Steven Rostedt (Google) --- kernel/trace/trace_output.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/kernel/trace/trace_output.c b/kernel/trace/trace_output.c index b9d2c64c0648..48de93598897 100644 --- a/kernel/trace/trace_output.c +++ b/kernel/trace/trace_output.c @@ -1233,6 +1233,7 @@ static enum print_line_t trace_stack_print(struct trace_iterator *iter, struct trace_seq *s = &iter->seq; unsigned long *p; unsigned long *end; + long delta = iter->tr->text_delta; trace_assign_type(field, iter->ent); end = (unsigned long *)((long)iter->ent + iter->ent_size); @@ -1245,7 +1246,7 @@ static enum print_line_t trace_stack_print(struct trace_iterator *iter, break; trace_seq_puts(s, " => "); - seq_print_ip_sym(s, *p, flags); + seq_print_ip_sym(s, (*p) + delta, flags); trace_seq_putc(s, '\n'); } -- cgit