From: Mateusz Nosek <mateusznosek0@xxxxxxxxx>
Variable 'want_page_poisoning' is a switch deciding if page poisoning
should be enabled. This patch changes it to be static key.
Signed-off-by: Mateusz Nosek <mateusznosek0@xxxxxxxxx>
---
mm/page_poison.c | 20 +++++++++++++++-----
1 file changed, 15 insertions(+), 5 deletions(-)
diff --git a/mm/page_poison.c b/mm/page_poison.c
index 34b9181ee5d1..ae0482cded87 100644
--- a/mm/page_poison.c
+++ b/mm/page_poison.c
@@ -8,13 +8,23 @@
#include <linux/ratelimit.h>
#include <linux/kasan.h>
-static bool want_page_poisoning __read_mostly;
+static DEFINE_STATIC_KEY_FALSE_RO(want_page_poisoning);
static int __init early_page_poison_param(char *buf)
{
- if (!buf)
- return -EINVAL;
- return strtobool(buf, &want_page_poisoning);
+ int ret;
+ bool tmp;
+
+ ret = strtobool(buf, &tmp);
+ if (ret)
+ return ret;
+
+ if (tmp)
+ static_branch_enable(&want_page_poisoning);
+ else
+ static_branch_disable(&want_page_poisoning);
+
+ return 0;
}
early_param("page_poison", early_page_poison_param);
@@ -31,7 +41,7 @@ bool page_poisoning_enabled(void)
* Page poisoning is debug page alloc for some arches. If
* either of those options are enabled, enable poisoning.
*/
- return (want_page_poisoning ||
+ return (static_branch_unlikely(&want_page_poisoning) ||
(!IS_ENABLED(CONFIG_ARCH_SUPPORTS_DEBUG_PAGEALLOC) &&
debug_pagealloc_enabled()));
}
--
2.20.1
