x86, perf: Add a build-time sanity test to the x86 decoder
Add a sanity test of x86 insn decoder against a stream
of randomly generated input, at build time.
This test is also able to reproduce any bug that might
trigger by allowing the passing of random-seed and
iteration-number to the test, or by passing input
which has invalid byte code.
Changes in V2:
- Code cleanup.
- Show how to reproduce the error by insn_sanity test.
Signed-off-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: acme@redhat.com
Cc: ming.m.lin@intel.com
Cc: robert.richter@amd.com
Cc: ravitillo@lbl.gov
Cc: yrl.pp-manager.tt@hitachi.com
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Stephane Eranian <eranian@google.com>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20111020140109.20938.92572.stgit@localhost.localdomain
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/arch/x86/include/asm/insn.h b/arch/x86/include/asm/insn.h
index 88c765e1..74df3f1 100644
--- a/arch/x86/include/asm/insn.h
+++ b/arch/x86/include/asm/insn.h
@@ -137,6 +137,13 @@
return (insn->vex_prefix.value != 0);
}
+/* Ensure this instruction is decoded completely */
+static inline int insn_complete(struct insn *insn)
+{
+ return insn->opcode.got && insn->modrm.got && insn->sib.got &&
+ insn->displacement.got && insn->immediate.got;
+}
+
static inline insn_byte_t insn_vex_m_bits(struct insn *insn)
{
if (insn->vex_prefix.nbytes == 2) /* 2 bytes VEX */
