[PATCH kcsan 15/19] kcsan: Show message if enabled early

From: paulmck
Date: Mon Aug 31 2020 - 14:20:11 EST


From: Marco Elver <elver@xxxxxxxxxx>

Show a message in the kernel log if KCSAN was enabled early.

Signed-off-by: Marco Elver <elver@xxxxxxxxxx>
Signed-off-by: Paul E. McKenney <paulmck@xxxxxxxxxx>
---
kernel/kcsan/core.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/kernel/kcsan/core.c b/kernel/kcsan/core.c
index 99e5044..b176400 100644
--- a/kernel/kcsan/core.c
+++ b/kernel/kcsan/core.c
@@ -1,5 +1,7 @@
// SPDX-License-Identifier: GPL-2.0

+#define pr_fmt(fmt) "kcsan: " fmt
+
#include <linux/atomic.h>
#include <linux/bug.h>
#include <linux/delay.h>
@@ -463,7 +465,7 @@ kcsan_setup_watchpoint(const volatile void *ptr, size_t size, int type)

if (IS_ENABLED(CONFIG_KCSAN_DEBUG)) {
kcsan_disable_current();
- pr_err("KCSAN: watching %s, size: %zu, addr: %px [slot: %d, encoded: %lx]\n",
+ pr_err("watching %s, size: %zu, addr: %px [slot: %d, encoded: %lx]\n",
is_write ? "write" : "read", size, ptr,
watchpoint_slot((unsigned long)ptr),
encode_watchpoint((unsigned long)ptr, size, is_write));
@@ -623,8 +625,10 @@ void __init kcsan_init(void)
* We are in the init task, and no other tasks should be running;
* WRITE_ONCE without memory barrier is sufficient.
*/
- if (kcsan_early_enable)
+ if (kcsan_early_enable) {
+ pr_info("enabled early\n");
WRITE_ONCE(kcsan_enabled, true);
+ }
}

/* === Exported interface =================================================== */
--
2.9.5