[PATCH] Fix bug #10831 - SIGCLD Signal handler not correctly reinstalled on old library code use - smbrun etc.

[Martin Schwenke]

On Tue, 23 Sep 2014 15:44:25 -0700, Jeremy Allison <jra at samba.org>
wrote:

> Some of the old library util code can
> overwrite the SIGCHLD signal handler
> carefully set up by smbd and winbindd
> via tevent :-(.
> 
> It's used in blocking calls when launching
> scripts as in smbrun(), but it leaves
> the new handler in place when it exits
> from smbrun(), rather than restoring
> the original signal handler.
> 
> The first patch changes CatchChild()
> and CatchChildLeaveStatus() to return
> the existing handler so it can be
> saved and restored.
> 
> The second patch fixes smbrun() and
> the change password code (which
> also invokes a child process) to
> store and restore the existing
> handler.
> 
> Review most appreciated !

Today I learned about:

* signal handling; and

* functions that return function pointers (without using a typedef).

;-)

Just out of interest, since it is only the CatchChildLeaveStatus() calls
that causes problems, why bother changing CatchChild()?  I looked over
the various calls to CatchChild() and they seem OK.

I'm happy to say...

Reviewed-by: Martin Schwenke <martin at meltin.net>

However, I won't push in case you decide that CatchChild() doesn't need
to be changed and/or you want to increase confidence by getting a
review from someone who didn't learn about these things today...  ;-)

peace & happiness,
martin