From 6d02eefecc5e3887eea08f3df5e0f2af6eb35447 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Fri, 19 Jul 2024 10:13:12 -0400 Subject: [PATCH] tracing: Fix ifdef of snapshots to not prevent last_boot_info file The mapping of the ring buffer to memory allocated at boot up will also expose a "last_boot_info" to help tooling to read the raw data from the last boot. As instances that have their ring buffer mapped to fixed memory cannot perform snapshots, they can either have the "snapshot" file or the "last_boot_info" file, but not both. The code that added the "last_boot_info" file failed to notice that the "snapshot" creation was inside a "#ifdef CONFIG_TRACER_SNAPSHOT" and incorrectly placed the creation of the "last_boot_info" file within the ifdef block. Not only does it cause a warning when CONFIG_TRACER_SNAPSHOT is not enabled, it also incorrectly prevents the file from appearing. Link: https://lore.kernel.org/all/20240719102640.718554-1-arnd@kernel.org/ Cc: Masami Hiramatsu Cc: Mathieu Desnoyers Reported-by: Arnd Bergmann Link: https://lore.kernel.org/20240719101312.3d4ac707@rorschach.local.home Fixes: 7a1d1e4b9639 ("tracing/ring-buffer: Add last_boot_info file to boot instance") Signed-off-by: Steven Rostedt (Google) --- kernel/trace/trace.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index d0af984a5337d..8e5a4ca9fd70e 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -9828,15 +9828,15 @@ init_tracer_tracefs(struct trace_array *tr, struct dentry *d_tracer) if (ftrace_create_function_files(tr, d_tracer)) MEM_FAIL(1, "Could not allocate function filter files"); -#ifdef CONFIG_TRACER_SNAPSHOT if (tr->range_addr_start) { trace_create_file("last_boot_info", TRACE_MODE_READ, d_tracer, tr, &last_boot_fops); +#ifdef CONFIG_TRACER_SNAPSHOT } else { trace_create_file("snapshot", TRACE_MODE_WRITE, d_tracer, tr, &snapshot_fops); - } #endif + } trace_create_file("error_log", TRACE_MODE_WRITE, d_tracer, tr, &tracing_err_log_fops); -- 2.47.2