On Thu, 21 May 2026 11:16:30 -0400
Steven Rostedt [off-list ref] wrote:

On Thu, 21 May 2026 23:57:16 +0900
"Masami Hiramatsu (Google)" [off-list ref] wrote:

quoted

@@ -4804,6 +4806,7 @@ struct trace_mod_entry {
 struct trace_scratch {
 	unsigned int		clock_id;
 	unsigned long		text_addr;
+	u8			boot_id[UUID_SIZE];
 	unsigned long		nr_entries;
 	struct trace_mod_entry	entries[];
 };

I just don't like wasting scratch space if boot_id isn't defined. But I
can't figure out a way to optionally have it there without wasting space
anyway.

Yeah, it needs to be placed in the scratch area or ring-buffer meta page.
In most cases the boot_id is enabled (random subsystem seems to provide
this UUID always), so it will be rarely waste of memory except
CONFIG_SYSCTL=n.

If the get_boot_id() is accepted by the random folks, then I'm fine with
this change.

Yeah, BTW, Sashiko found this can be initialized before we get enough
entropy for random seed. Maybe we need one more delay.

Thank you,

-- Steve

-- 
Masami Hiramatsu (Google) [off-list ref]