1 files changed, 64 insertions, 3 deletions

diff --git a/usr/src/cmd/mdb/common/modules/mdb_ks/mdb_ks.c b/usr/src/cmd/mdb/common/modules/mdb_ks/mdb_ks.c
index 85f3839c96..68b2e9d362 100644
--- a/usr/src/cmd/mdb/common/modules/mdb_ks/mdb_ks.c
+++ b/usr/src/cmd/mdb/common/modules/mdb_ks/mdb_ks.c
@@ -60,6 +60,12 @@
 
 #define	MDB_PATH_NELEM	256			/* Maximum path components */
 
+/*
+ * Due to mdb_param.h shenanigans, there's no simple way to include string.h
+ * here...
+ */
+extern char *strtok(char *restrict, const char *restrict);
+
 typedef struct mdb_path {
 	size_t mdp_nelem;			/* Number of components */
 	uint_t mdp_complete;			/* Path completely resolved? */
@@ -1811,18 +1817,73 @@ mdb_get_lbolt(void)
 	return ((ts/nsec) - lbi.lbi_debug_time);
 }
 
+#define	startswith(a, b) (strncmp((a), (b), strlen(b)) == 0)
+
+/*
+ * Dig out the branch and revision of the illumos-joyent repo, if we were
+ * provided with it.  This is a rather fragile JSON parser, in that it requires
+ * JSON formatted exactly as per the boot_archive.gitstatus file that
+ * "buildversion" is built from.
+ */
 void
 mdb_print_buildversion(void)
 {
+	boolean_t in_joyent = B_FALSE;
 	GElf_Sym sym;
 
-	if (mdb_lookup_by_name("buildversion", &sym) != 0)
-		return;
+	if (mdb_lookup_by_name("buildversion", &sym) != 0) {
+		/* Older kernels used this name. */
+		if (mdb_lookup_by_name("gitstatus_start", &sym) != 0)
+			return;
+	}
 
 	char *str = mdb_zalloc(4096, UM_SLEEP | UM_GC);
 
 	if (mdb_readstr(str, 4096, sym.st_value) < 1)
 		return;
 
-	mdb_printf("build version: %s\n", str);
+	/*
+	 * Each line is of the form
+	 *
+	 *	"repo": "smartos-live",
+	 */
+	for (char *line = strtok(str, "\n"); line != NULL;
+	    line = strtok(NULL, "\n")) {
+		/* skip whitespace and first " */
+		line += strspn(line, " \t\"");
+
+		if (startswith(line, "repo")) {
+			line += sizeof ("repo") - 1;
+			line += strspn(line, " \t\":");
+
+			if (startswith(line, "illumos-joyent"))
+				in_joyent = B_TRUE;
+			else if (in_joyent)
+				return;
+			continue;
+		}
+
+		if (!in_joyent)
+			continue;
+
+		if (startswith(line, "branch")) {
+			char *trail = strrchr(line, '"');
+			if (trail != NULL)
+				*trail = '\0';
+			line += sizeof ("branch") - 1;
+			line += strspn(line, " \t\":");
+			mdb_printf("git branch: %s\n", line);
+			continue;
+		}
+
+		if (startswith(line, "rev")) {
+			char *trail = strrchr(line, '"');
+			if (trail != NULL)
+				*trail = '\0';
+			line += sizeof ("rev") - 1;
+			line += strspn(line, " \t\":");
+			mdb_printf("git rev: %s\n", line);
+			continue;
+		}
+	}
 }