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-rw-r--r--arch/arm/kernel/traps.c10
1 files changed, 10 insertions, 0 deletions
diff --git a/arch/arm/kernel/traps.c b/arch/arm/kernel/traps.c
index cab094c234ee..9433e8a12b5e 100644
--- a/arch/arm/kernel/traps.c
+++ b/arch/arm/kernel/traps.c
@@ -818,10 +818,20 @@ void __init early_trap_init(void *vectors_base)
extern char __vectors_start[], __vectors_end[];
extern char __kuser_helper_start[], __kuser_helper_end[];
int kuser_sz = __kuser_helper_end - __kuser_helper_start;
+ unsigned i;
vectors_page = vectors_base;
/*
+ * Poison the vectors page with an undefined instruction. This
+ * instruction is chosen to be undefined for both ARM and Thumb
+ * ISAs. The Thumb version is an undefined instruction with a
+ * branch back to the undefined instruction.
+ */
+ for (i = 0; i < PAGE_SIZE / sizeof(u32); i++)
+ ((u32 *)vectors_base)[i] = 0xe7fddef1;
+
+ /*
* Copy the vectors, stubs and kuser helpers (in entry-armv.S)
* into the vector page, mapped at 0xffff0000, and ensure these
* are visible to the instruction stream.