[tip:x86/cleanups] x86/insn-eval: Mark expected switch-case fall-through

["tip-bot for Gustavo A. R. Silva" <tipbot@zytor.com>]

Commit-ID:  89da3446294a8b811b28a4807e74e7ee7044d49f
Gitweb:     https://git.kernel.org/tip/89da3446294a8b811b28a4807e74e7ee7044d49f
Author:     Gustavo A. R. Silva <gustavo@embeddedor.com>
AuthorDate: Fri, 25 Jan 2019 14:55:20 -0600
Committer:  Borislav Petkov <bp@suse.de>
CommitDate: Sat, 26 Jan 2019 10:46:42 +0100

x86/insn-eval: Mark expected switch-case fall-through

In preparation to enable -Wimplicit-fallthrough by default, mark
switch-case statements where fall-through is intentional, explicitly.

Thus fix the following warning:

  arch/x86/lib/insn-eval.c: In function ‘resolve_default_seg’:
  arch/x86/lib/insn-eval.c:179:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
     if (insn->addr_bytes == 2)
        ^
  arch/x86/lib/insn-eval.c:182:2: note: here
    case -EDOM:
    ^~~~

Warning level 3 was used: -Wimplicit-fallthrough=3

This is part of the ongoing efforts to enable -Wimplicit-fallthrough by
default.

 [ bp: Massage commit message. ]

Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: x86-ml <x86@kernel.org>
Link: https://lkml.kernel.org/r/20190125205520.GA9602@embeddedor
---
 arch/x86/lib/insn-eval.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/arch/x86/lib/insn-eval.c b/arch/x86/lib/insn-eval.c
index 9119d8e41f1f..cf00ab6c6621 100644
--- a/arch/x86/lib/insn-eval.c
+++ b/arch/x86/lib/insn-eval.c
@@ -179,6 +179,8 @@ static int resolve_default_seg(struct insn *insn, struct pt_regs *regs, int off)
 		if (insn->addr_bytes == 2)
 			return -EINVAL;
 
+		/* fall through */
+
 	case -EDOM:
 	case offsetof(struct pt_regs, bx):
 	case offsetof(struct pt_regs, si):