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&lt;jason.wessel@windriver.com>
CC: Andrew Morton <akpm@linux-foundation.org>
CC: Ingo Molnar <mingo@elte.hu>
CC: linux-mm@kvack.org

parent 9264b278

mm/highmem.c

+7 −0

Original line number	Diff line number	Diff line
		@@ -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 @@ void debug_kmap_atomic(enum km_type type)
		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