New configuration option: DisableDebuggerAttachment

If set to 1, Tor will attempt to prevent basic debugging
attachment attempts by other processes. (Default: 1)

Supports Mac OS X and Gnu/Linux.

Sebastian provided useful feedback and refactoring suggestions.

Signed-off-by: Jacob Appelbaum <jacob@appelbaum.net>

1 files changed, 14 insertions, 0 deletions

diff --git a/doc/tor.1.txt b/doc/tor.1.txt
index 7d72350eb..c37c44c7b 100644
--- a/doc/tor.1.txt
+++ b/doc/tor.1.txt
@@ -251,6 +251,20 @@ Other options can be specified either on the command-line (--option
     option requires that you start your Tor as root, and you should use the
     **User** option to properly reduce Tor's privileges. (Default: 0)
 
+**DisableDebuggerAttachment** **0**|**1**::
+   If set to 1, Tor will attempt to prevent basic debugging attachment attempts
+   by other processes. It has no impact for users who wish to attach if they
+   have CAP_SYS_PTRACE or if they are root.  We believe that this feature
+   works on modern Gnu/Linux distributions, and that it may also work on *BSD
+   systems (untested).  Some modern Gnu/Linux systems such as Ubuntu have the
+   kernel.yama.ptrace_scope sysctl and by default enable it as an attempt to
+   limit the PTRACE scope for all user processes by default. This feature will
+   attempt to limit the PTRACE scope for Tor specifically - it will not attempt
+   to alter the system wide ptrace scope as it may not even exist. If you wish
+   to attach to Tor with a debugger such as gdb or strace you will want to set
+   this to 0 for the duration of your debugging. Normal users should leave it
+   on. (Default: 1)
+ 
 **FetchDirInfoEarly** **0**|**1**::
     If set to 1, Tor will always fetch directory information like other
     directory caches, even if you don't meet the normal criteria for fetching