commit bc7b765ab71f967eb2a9c3da111d7529eec46fbe
Author: John Baldwin <jhb@FreeBSD.org>
Date:   Sun Jul 3 11:56:21 2016 -0700

    Pass SIGLIBRT directly to child processes.
    
    FreeBSD's librt uses SIGLIBRT as an internal signal to implement
    SIGEV_THREAD sigevent notifications.  Similar to SIGLWP or SIGCANCEL
    this signal should be passed through to child processes by default.
    
    include/ChangeLog:
    
    	* signals.def: Add GDB_SIGNAL_LIBRT.
    
    gdb/ChangeLog:
    
    	* common/signals.c (gdb_signal_from_host): Handle SIGLIBRT.
    	(do_gdb_signal_to_host): Likewise.
    	* infrun.c (_initialize_infrun): Pass GDB_SIGNAL_LIBRT through to
    	programs.
    	* proc-events.c (signal_table): Add entry for SIGLIBRT.

diff --git gdb/common/signals.c gdb/common/signals.c
index 45c0c73..f84935d 100644
--- gdb/common/signals.c
+++ gdb/common/signals.c
@@ -331,6 +331,10 @@ gdb_signal_from_host (int hostsig)
   if (hostsig == SIGINFO)
     return GDB_SIGNAL_INFO;
 #endif
+#if defined (SIGLIBRT)
+  if (hostsig == SIGLIBRT)
+    return GDB_SIGNAL_LIBRT;
+#endif
 
 #if defined (REALTIME_LO)
   if (hostsig >= REALTIME_LO && hostsig < REALTIME_HI)
@@ -584,6 +588,10 @@ do_gdb_signal_to_host (enum gdb_signal oursig,
     case GDB_SIGNAL_INFO:
       return SIGINFO;
 #endif
+#if defined (SIGLIBRT)
+    case GDB_SIGNAL_LIBRT:
+      return SIGLIBRT;
+#endif
 
     default:
 #if defined (REALTIME_LO)
diff --git gdb/infrun.c gdb/infrun.c
index 70a0790..257ac8a 100644
--- gdb/infrun.c
+++ gdb/infrun.c
@@ -9409,6 +9409,8 @@ leave it stopped or free to run as needed."),
   signal_print[GDB_SIGNAL_WAITING] = 0;
   signal_stop[GDB_SIGNAL_CANCEL] = 0;
   signal_print[GDB_SIGNAL_CANCEL] = 0;
+  signal_stop[GDB_SIGNAL_LIBRT] = 0;
+  signal_print[GDB_SIGNAL_LIBRT] = 0;
 
   /* Update cached state.  */
   signal_cache_update (-1);
diff --git gdb/proc-events.c gdb/proc-events.c
index b291d31..daa6f58 100644
--- gdb/proc-events.c
+++ gdb/proc-events.c
@@ -1536,6 +1536,9 @@ static struct trans signal_table[] =
 #ifdef SIGAIO
   { SIGAIO, "SIGAIO", "Asynchronous I/O signal" },
 #endif
+#ifdef SIGLIBRT
+  { SIGLIBRT, "SIGLIBRT", "Used by librt" },
+#endif
 
   /* FIXME: add real-time signals.  */
 };
diff --git include/gdb/ChangeLog include/gdb/ChangeLog
index f05ba4b..05f127e 100644
--- include/gdb/ChangeLog
+++ include/gdb/ChangeLog
@@ -1,3 +1,7 @@
+2016-07-15  John Baldwin  <jhb@FreeBSD.org>
+
+	* signals.def: Add GDB_SIGNAL_LIBRT.
+
 2016-01-06  Mike Frysinger  <vapier@gentoo.org>
 
 	* remote-sim.h (sim_open): Mark argv const.
diff --git include/gdb/signals.def include/gdb/signals.def
index 61cc88c..2b30e71 100644
--- include/gdb/signals.def
+++ include/gdb/signals.def
@@ -194,7 +194,9 @@ SET (GDB_EXC_EMULATION, 148, "EXC_EMULATION", "Emulation instruction")
 SET (GDB_EXC_SOFTWARE, 149, "EXC_SOFTWARE", "Software generated exception")
 SET (GDB_EXC_BREAKPOINT, 150, "EXC_BREAKPOINT", "Breakpoint")
 
+SET (GDB_SIGNAL_LIBRT, 151, "SIGLIBRT", "librt internal signal")
+
 /* If you are adding a new signal, add it just above this comment.  */
 
 /* Last and unused enum value, for sizing arrays, etc.  */
-SET (GDB_SIGNAL_LAST, 151, NULL, "GDB_SIGNAL_LAST")
+SET (GDB_SIGNAL_LAST, 152, NULL, "GDB_SIGNAL_LAST")