* DevNotes: Add entry cgf-000022.

* cygtls.h (_cygtls::func): Define as a sa_sigaction style function.
* exceptions.cc (sig_handle_tty_stop): Ditto.
(_cygtls::interrupt_setup): Fix coercion to accommodate 'func' change.
(ctrl_c_handler): Use tty kill_pgrp to send a signal.
(sigpacket::process): Don't process sigflush here.
(_cygtls::call_signal_handler): Reorganize to avoid a race.  Always call
sa_sigaction style function.
* fhandler_termios.cc (is_flush_sig): Define new function.
(tty_min::kill_pgrp): Handle tty flush when signal detected.
(fhandler_termios::bg_check): Be slightly more paranoid about checking for
valid tty.
(fhandler_termios::sigflush): Don't flush unless tty owner.
* fhandler_tty.cc (fhandler_pty_slave::ioctl): Use tty kill_pgrp to send
signal.
(fhandler_pty_master::ioctl): Ditto.
* signal.cc (killsys): Delete definition.
* sigproc.h (killsys): Delete declaration.
* include/cygwin/signal.h (siginfo_t): Simplify union/struct nesting slightly.
Implement mechanism to allow cygwin data passing.

winsup/cygwin/include/cygwin/signal.h

@@ -1,7 +1,7 @@
 /* signal.h
 
-  Copyright 2003, 2004, 2005, 2006, 2007, 2008, 2010, 2011, 2012, 2013 Red
-  Hat, Inc.
+  Copyright 2003, 2004, 2005, 2006, 2007, 2008, 2010, 2011, 2012, 2013
+  Red Hat, Inc.
 
   This file is part of Cygwin.
 
@@ -90,6 +90,19 @@ struct _sigcommune
   };
 };
 
+#define __SI_PAD_SIZE 32
+#ifdef __INSIDE_CYGWIN__
+# ifndef max
+#   define max(a,b) (((a) > (b)) ? (a) : (b))
+# endif /*max*/
+# define __uint32_size(__x) (max(sizeof (__x) / sizeof (uint32_t), 1))
+
+/* This padding represents the elements of the last struct in siginfo_t,
+   aligning the elements to the end to avoid conflicts with other struct
+   members. */
+# define __SI_CYG_PAD (__SI_PAD_SIZE - __uint32_size (void *))
+#endif /*__INSIDE_CYGWIN__*/
+
 typedef struct
 {
   int si_signo;				/* signal number */
@@ -100,26 +113,21 @@ typedef struct
 
   __extension__ union
   {
-    __uint32_t __pad[32];		/* plan for future growth */
+    __uint32_t __pad[__SI_PAD_SIZE];	/* plan for future growth */
     struct _sigcommune _si_commune;	/* cygwin ipc */
-    __extension__ union
+    __extension__ struct
     {
-      /* timers */
-      struct
+      __extension__ union
       {
-	union
-	{
-	  struct
-	  {
-	    timer_t si_tid;		/* timer id */
-	    unsigned int si_overrun;	/* overrun count */
-	  };
-	  sigval_t si_sigval;		/* signal value */
-	  sigval_t si_value;		/* signal value */
-	};
+	sigval_t si_sigval;		/* signal value */
+	sigval_t si_value;		/* signal value */
+      };
+      __extension__ struct
+      {
+	timer_t si_tid;			/* timer id */
+	unsigned int si_overrun;	/* overrun count */
       };
     };
-
     /* SIGCHLD */
     __extension__ struct
     {
@@ -128,13 +136,17 @@ typedef struct
       clock_t si_stime;			/* system time */
     };
 
-    __extension__ struct
+    void *si_addr;			/* faulting address for core dumping
+					   signals */
+    /* Cygwin internal fields */
+#ifdef __INSIDE_CYGWIN__
+    __extension__ struct 
     {
-      /* core dumping signals */
-      void *si_addr;			/* faulting address */
+      __uint32_t __pad2[__SI_CYG_PAD];	/* Locate at end of struct */
       void *si_cyg;			/* pointer to block containing
 					   cygwin-special info */
     };
+#endif /*__INSIDE_CYGWIN__*/
   };
 } siginfo_t;
 #pragma pack(pop)