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-rw-r--r--arch/arm/net/bpf_jit_32.h14
1 files changed, 14 insertions, 0 deletions
diff --git a/arch/arm/net/bpf_jit_32.h b/arch/arm/net/bpf_jit_32.h
index afb84621ff6f..b2d7d92859d3 100644
--- a/arch/arm/net/bpf_jit_32.h
+++ b/arch/arm/net/bpf_jit_32.h
@@ -114,6 +114,20 @@
#define ARM_INST_UMULL 0x00800090
+/*
+ * Use a suitable undefined instruction to use for ARM/Thumb2 faulting.
+ * We need to be careful not to conflict with those used by other modules
+ * (BUG, kprobes, etc) and the register_undef_hook() system.
+ *
+ * The ARM architecture reference manual guarantees that the following
+ * instruction space will produce an undefined instruction exception on
+ * all CPUs:
+ *
+ * ARM: xxxx 0111 1111 xxxx xxxx xxxx 1111 xxxx ARMv7-AR, section A5.4
+ * Thumb: 1101 1110 xxxx xxxx ARMv7-M, section A5.2.6
+ */
+#define ARM_INST_UDF 0xe7fddef1
+
/* register */
#define _AL3_R(op, rd, rn, rm) ((op ## _R) | (rd) << 12 | (rn) << 16 | (rm))
/* immediate */