[PATCH] KVM: x86: Fix x86_decode_insn() return when fetching insn bytes fails

From: Sean Christopherson
Date: Thu Aug 15 2019 - 12:20:34 EST


Jump to the common error handling in x86_decode_insn() if
__do_insn_fetch_bytes() fails so that its error code is converted to the
appropriate return type. Although the various helpers used by
x86_decode_insn() return X86EMUL_* values, x86_decode_insn() itself
returns EMULATION_FAILED or EMULATION_OK.

This doesn't cause a functional issue as the sole caller,
x86_emulate_instruction(), currently only cares about success vs.
failure, and success is indicated by '0' for both types
(X86EMUL_CONTINUE and EMULATION_OK).

Fixes: 285ca9e948fa ("KVM: emulate: speed up do_insn_fetch")
Signed-off-by: Sean Christopherson <sean.j.christopherson@xxxxxxxxx>
---
arch/x86/kvm/emulate.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index 8e409ad448f9..6d2273e71020 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -5126,7 +5126,7 @@ int x86_decode_insn(struct x86_emulate_ctxt *ctxt, void *insn, int insn_len)
else {
rc = __do_insn_fetch_bytes(ctxt, 1);
if (rc != X86EMUL_CONTINUE)
- return rc;
+ goto done;
}

switch (mode) {
--
2.22.0