From 014940bad8e46ca7bd0483f760f9cba60088a3d4 Mon Sep 17 00:00:00 2001
From: Oleg Nesterov <oleg@redhat.com>
Date: Thu, 3 Apr 2014 20:20:10 +0200
Subject: [PATCH] uprobes/x86: Send SIGILL if arch_uprobe_post_xol() fails

Currently the error from arch_uprobe_post_xol() is silently ignored.
This doesn't look good and this can lead to the hard-to-debug problems.

1. Change handle_singlestep() to loudly complain and send SIGILL.

   Note: this only affects x86, ppc/arm can't fail.

2. Change arch_uprobe_post_xol() to call arch_uprobe_abort_xol() and
   avoid TF games if it is going to return an error.

   This can help to to analyze the problem, if nothing else we should
   not report ->ip = xol_slot in the core-file.

   Note: this means that handle_riprel_post_xol() can be called twice,
   but this is fine because it is idempotent.

Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Reviewed-by: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Reviewed-by: Jim Keniston <jkenisto@us.ibm.com>
---
Reading git-format-patch failed