mm,kdb,kgdb: Add a debug reference for the kdb kmap usage
The kdb kmap should never get used outside of the kernel debugger
exception context.
Signed-off-by: Jason Wessel<jason.wessel@windriver.com>
CC: Andrew Morton <akpm@linux-foundation.org>
CC: Ingo Molnar <mingo@elte.hu>
CC: linux-mm@kvack.org
diff --git a/mm/highmem.c b/mm/highmem.c
index 66baa20..7a0aa1b 100644
--- a/mm/highmem.c
+++ b/mm/highmem.c
@@ -26,6 +26,7 @@
#include <linux/init.h>
#include <linux/hash.h>
#include <linux/highmem.h>
+#include <linux/kgdb.h>
#include <asm/tlbflush.h>
/*
@@ -470,6 +471,12 @@
warn_count--;
}
}
+#ifdef CONFIG_KGDB_KDB
+ if (unlikely(type == KM_KDB && atomic_read(&kgdb_active) == -1)) {
+ WARN_ON(1);
+ warn_count--;
+ }
+#endif /* CONFIG_KGDB_KDB */
}
#endif