git: fe51b5a76de3 - main - kern_tslog: Include tslog data from loader

[Colin Percival]

The branch main has been updated by cperciva:

URL: https://cgit.FreeBSD.org/src/commit/?id=fe51b5a76de38d20cddc05a4c6cb1103d1a0547e

commit fe51b5a76de38d20cddc05a4c6cb1103d1a0547e
Author:     Colin Percival <cperciva at FreeBSD.org>
AuthorDate: 2021-05-30 23:25:01 +0000
Commit:     Colin Percival <cperciva at FreeBSD.org>
CommitDate: 2021-06-21 03:09:47 +0000

    kern_tslog: Include tslog data from loader
    
    The i386 loader (and hopefully others to come) now passes tslog data
    as a "preloaded module".  Include this in the data returned by the
    debug.tslog sysctl.
    
    Reviewed by:    kevans
---
 sys/kern/kern_tslog.c | 15 +++++++++++++++
 1 file changed, 15 insertions(+)

diff --git a/sys/kern/kern_tslog.c b/sys/kern/kern_tslog.c
index a0cb230f191c..dd3b25158340 100644
--- a/sys/kern/kern_tslog.c
+++ b/sys/kern/kern_tslog.c
@@ -28,6 +28,8 @@
 __FBSDID("$FreeBSD$");
 
 #include <sys/param.h>
+#include <sys/kernel.h>
+#include <sys/linker.h>
 #include <sys/sbuf.h>
 #include <sys/sysctl.h>
 #include <sys/systm.h>
@@ -74,6 +76,9 @@ sysctl_debug_tslog(SYSCTL_HANDLER_ARGS)
 	int error;
 	struct sbuf *sb;
 	size_t i, limit;
+	caddr_t loader_tslog;
+	void * loader_tslog_buf;
+	size_t loader_tslog_len;
 
 	/*
 	 * This code can race against the code in tslog() which stores
@@ -84,6 +89,16 @@ sysctl_debug_tslog(SYSCTL_HANDLER_ARGS)
 	 * anyone will ever experience this race.
 	 */
 	sb = sbuf_new_for_sysctl(NULL, NULL, 1024, req);
+
+	/* Get data from the boot loader, if it provided any. */
+	loader_tslog = preload_search_by_type("TSLOG data");
+	if (loader_tslog != NULL) {
+		loader_tslog_buf = preload_fetch_addr(loader_tslog);
+		loader_tslog_len = preload_fetch_size(loader_tslog);
+		sbuf_bcat(sb, loader_tslog_buf, loader_tslog_len);
+	}
+
+	/* Add data logged within the kernel. */
 	limit = MIN(nrecs, nitems(timestamps));
 	for (i = 0; i < limit; i++) {
 		sbuf_printf(sb, "%p", timestamps[i].td);