[tip:x86/urgent] x86/ptrace: Mark expected switch fall-through

[tip-bot for Gustavo A. R. Silva]

Commit-ID:  4ab9ab656a6cea5257bfa31f00c922d68f7a5c2f
Gitweb:     https://git.kernel.org/tip/4ab9ab656a6cea5257bfa31f00c922d68f7a5c2f
Author:     Gustavo A. R. Silva <gustavo@xxxxxxxxxxxxxx>
AuthorDate: Mon, 5 Aug 2019 14:56:54 -0500
Committer:  Thomas Gleixner <tglx@xxxxxxxxxxxxx>
CommitDate: Wed, 7 Aug 2019 15:12:01 +0200

x86/ptrace: Mark expected switch fall-through

Mark switch cases where we are expecting to fall through.

Fix the following warning (Building: allnoconfig i386):

arch/x86/kernel/ptrace.c:202:6: warning: this statement may fall through [-Wimplicit-fallthrough=]
   if (unlikely(value == 0))
      ^
arch/x86/kernel/ptrace.c:206:2: note: here
  default:
  ^~~~~~~

Signed-off-by: Gustavo A. R. Silva <gustavo@xxxxxxxxxxxxxx>
Signed-off-by: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
Reviewed-by: Kees Cook <keescook@xxxxxxxxxxxx>
Link: 20190805195654.GA17831@embeddedor">https://lkml.kernel.org/r/20190805195654.GA17831@embeddedor

---
 arch/x86/kernel/ptrace.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/arch/x86/kernel/ptrace.c b/arch/x86/kernel/ptrace.c
index 0fdbe89d0754..3c5bbe8e4120 100644
--- a/arch/x86/kernel/ptrace.c
+++ b/arch/x86/kernel/ptrace.c
@@ -201,6 +201,7 @@ static int set_segment_reg(struct task_struct *task,
 	case offsetof(struct user_regs_struct, ss):
 		if (unlikely(value == 0))
 			return -EIO;
+		/* Else, fall through */
 
 	default:
 		*pt_regs_access(task_pt_regs(task), offset) = value;