From 5b38c1a3b807a7e7094b895635177a40b4bd257f Mon Sep 17 00:00:00 2001
From: Arran Cudbard-Bell <a.cudbardb@freeradius.org>
Date: Wed, 31 May 2023 18:17:45 -0400
Subject: [PATCH] Warn when we can't retrieve a core count

---
 src/lib/server/main_config.c |  4 ++++
 src/lib/util/hw.c            | 10 ++++++++--
 2 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/src/lib/server/main_config.c b/src/lib/server/main_config.c
index 7ab4be48c957c..a1377ac0a40e4 100644
--- a/src/lib/server/main_config.c
+++ b/src/lib/server/main_config.c
@@ -453,6 +453,10 @@ static int num_workers_dflt(CONF_PAIR **out, void *parent, CONF_SECTION *cs, fr_
 	main_config_t	*conf = parent;
 
 	value = fr_hw_num_cores_active();
+	if (value < 0) {
+		cf_log_pwarn(parent, "Failed retrieving core count, defaulting to 1 worker");
+		value = 1;
+	}
 
 	/*
 	 *	If we've got more than four times
diff --git a/src/lib/util/hw.c b/src/lib/util/hw.c
index c6a92646fdd0d..17ef9d1157369 100644
--- a/src/lib/util/hw.c
+++ b/src/lib/util/hw.c
@@ -25,6 +25,9 @@
 #define CORES_DEFAULT		1
 
 #include <freeradius-devel/util/hw.h>
+#include <freeradius-devel/util/syserror.h>
+#include <freeradius-devel/util/strerror.h>
+#include <errno.h>
 
 #if defined(__APPLE__) || defined(__FreeBSD__)
 #include <sys/sysctl.h>
@@ -96,13 +99,16 @@ uint32_t fr_hw_num_cores_active(void)
 	 *	You'd think this'd be enough to quiet clang scan,
 	 *	but it's not.
 	 */
-	if (unlikely((tsibs == 0) || (lcores == 0) || (lcores > tsibs))) return 1;
+	if (unlikely((tsibs == 0) || (lcores == 0) || (lcores > tsibs))) {
+		fr_strerror_const("Failed retrieving cpu topology info: %s", fr_syserror(errno));
+		return -1;
+	}
 
 #ifdef STATIC_ANALYZER
 	/*
 	 *	Prevent static analyzer from warning about divide by zero
 	 */
-	if ((tsibs / lcores) == 0) return 1;
+	if ((tsibs / lcores) == 0) return -1;
 #endif
 
 	return lcores / (tsibs / lcores);