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Diffstat (limited to 'mm/kasan/hw_tags.c')
-rw-r--r--mm/kasan/hw_tags.c60
1 files changed, 56 insertions, 4 deletions
diff --git a/mm/kasan/hw_tags.c b/mm/kasan/hw_tags.c
index 2aad21fda156..1df4ce803861 100644
--- a/mm/kasan/hw_tags.c
+++ b/mm/kasan/hw_tags.c
@@ -25,6 +25,12 @@ enum kasan_arg {
KASAN_ARG_ON,
};
+enum kasan_arg_mode {
+ KASAN_ARG_MODE_DEFAULT,
+ KASAN_ARG_MODE_SYNC,
+ KASAN_ARG_MODE_ASYNC,
+};
+
enum kasan_arg_stacktrace {
KASAN_ARG_STACKTRACE_DEFAULT,
KASAN_ARG_STACKTRACE_OFF,
@@ -38,6 +44,7 @@ enum kasan_arg_fault {
};
static enum kasan_arg kasan_arg __ro_after_init;
+static enum kasan_arg_mode kasan_arg_mode __ro_after_init;
static enum kasan_arg_stacktrace kasan_arg_stacktrace __ro_after_init;
static enum kasan_arg_fault kasan_arg_fault __ro_after_init;
@@ -45,6 +52,10 @@ static enum kasan_arg_fault kasan_arg_fault __ro_after_init;
DEFINE_STATIC_KEY_FALSE(kasan_flag_enabled);
EXPORT_SYMBOL(kasan_flag_enabled);
+/* Whether the asynchronous mode is enabled. */
+bool kasan_flag_async __ro_after_init;
+EXPORT_SYMBOL_GPL(kasan_flag_async);
+
/* Whether to collect alloc/free stack traces. */
DEFINE_STATIC_KEY_FALSE(kasan_flag_stacktrace);
@@ -68,6 +79,23 @@ static int __init early_kasan_flag(char *arg)
}
early_param("kasan", early_kasan_flag);
+/* kasan.mode=sync/async */
+static int __init early_kasan_mode(char *arg)
+{
+ if (!arg)
+ return -EINVAL;
+
+ if (!strcmp(arg, "sync"))
+ kasan_arg_mode = KASAN_ARG_MODE_SYNC;
+ else if (!strcmp(arg, "async"))
+ kasan_arg_mode = KASAN_ARG_MODE_ASYNC;
+ else
+ return -EINVAL;
+
+ return 0;
+}
+early_param("kasan.mode", early_kasan_mode);
+
/* kasan.stacktrace=off/on */
static int __init early_kasan_flag_stacktrace(char *arg)
{
@@ -115,7 +143,15 @@ void kasan_init_hw_tags_cpu(void)
return;
hw_init_tags(KASAN_TAG_MAX);
- hw_enable_tagging();
+
+ /*
+ * Enable async mode only when explicitly requested through
+ * the command line.
+ */
+ if (kasan_arg_mode == KASAN_ARG_MODE_ASYNC)
+ hw_enable_tagging_async();
+ else
+ hw_enable_tagging_sync();
}
/* kasan_init_hw_tags() is called once on boot CPU. */
@@ -132,6 +168,22 @@ void __init kasan_init_hw_tags(void)
/* Enable KASAN. */
static_branch_enable(&kasan_flag_enabled);
+ switch (kasan_arg_mode) {
+ case KASAN_ARG_MODE_DEFAULT:
+ /*
+ * Default to sync mode.
+ * Do nothing, kasan_flag_async keeps its default value.
+ */
+ break;
+ case KASAN_ARG_MODE_SYNC:
+ /* Do nothing, kasan_flag_async keeps its default value. */
+ break;
+ case KASAN_ARG_MODE_ASYNC:
+ /* Async mode enabled. */
+ kasan_flag_async = true;
+ break;
+ }
+
switch (kasan_arg_stacktrace) {
case KASAN_ARG_STACKTRACE_DEFAULT:
/* Default to enabling stack trace collection. */
@@ -194,10 +246,10 @@ void kasan_set_tagging_report_once(bool state)
}
EXPORT_SYMBOL_GPL(kasan_set_tagging_report_once);
-void kasan_enable_tagging(void)
+void kasan_enable_tagging_sync(void)
{
- hw_enable_tagging();
+ hw_enable_tagging_sync();
}
-EXPORT_SYMBOL_GPL(kasan_enable_tagging);
+EXPORT_SYMBOL_GPL(kasan_enable_tagging_sync);
#endif