Share fork_inferior et al with gdbserver

This is the most important (and the biggest, sorry) patch of the
series.  It moves fork_inferior from gdb/fork-child.c to
nat/fork-inferior.c and makes all the necessary adjustments to both
GDB and gdbserver to make sure everything works OK.

There is no "most important change" with this patch; all changes are
made in a progressive way, making sure that gdbserver had the
necessary features while not breaking GDB at the same time.

I decided to go ahead and implement a partial support for starting the
inferior with a shell on gdbserver, although the full feature comes in
the next patch.  The user won't have the option to disable the
startup-with-shell, and also won't be able to change which shell
gdbserver will use (other than setting the $SHELL environment
variable, that is).

Everything is working as expected, and no regressions were present
during the tests.

gdb/ChangeLog:
2017-06-07  Sergio Durigan Junior  <sergiodj@redhat.com>
	    Pedro Alves  <palves@redhat.com>

	* Makefile.in (HFILES_NO_SRCDIR): Add "common/common-inferior.h"
	and "nat/fork-inferior.h".
	* common/common-inferior.h: New file, with contents from
	"gdb/inferior.h".
	* commom/common-utils.c: Include "common-utils.h".
	(stringify_argv): New function.
	* common/common-utils.h (stringify_argv): New prototype.
	* configure.nat: Add "fork-inferior.o" as a dependency for
	"*linux*", "fbsd*" and "nbsd*" hosts.
	* corefile.c (get_exec_file): Update comment.
	* darwin-nat.c (darwin_ptrace_him): Call "gdb_startup_inferior"
	instead of "startup_inferior".
	(darwin_create_inferior): Call "add_thread_silent" after
	"fork_inferior".
	* fork-child.c: Cleanup unnecessary includes.
	(SHELL_FILE): Move to "common/common-fork-child.c".
	(environ): Likewise.
	(exec_wrapper): Initialize.
	(get_exec_wrapper): New function.
	(breakup_args): Move to "common/common-fork-child.c"; rename to
	"breakup_args_for_exec".
	(escape_bang_in_quoted_argument): Move to
	"common/common-fork-child.c".
	(saved_ui): New variable.
	(prefork_hook): New function.
	(postfork_hook): Likewise.
	(postfork_child_hook): Likewise.
	(gdb_startup_inferior): Likewise.
	(fork_inferior): Move to "common/common-fork-child.c".  Update
	function to support gdbserver.
	(startup_inferior): Likewise.
	* gdbcore.h (get_exec_file): Remove declaration.
	* gnu-nat.c (gnu_create_inferior): Call "gdb_startup_inferior"
	instead of "startup_inferior".  Call "add_thread_silent" after
	"fork_inferior".
	* inf-ptrace.c: Include "nat/fork-inferior.h" and "utils.h".
	(inf_ptrace_create_inferior): Call "gdb_startup_inferior"
	instead of "startup_inferior".  Call "add_thread_silent" after
	"fork_inferior".
	* inferior.h: Include "common-inferior.h".
	(trace_start_error): Move to "common/common-utils.h".
	(trace_start_error_with_name): Likewise.
	(fork_inferior): Move prototype to "nat/fork-inferior.h".
	(startup_inferior): Likewise.
	(gdb_startup_inferior): New prototype.
	* nat/fork-inferior.c: New file, with contents from "fork-child.c".
	* nat/fork-inferior.h: New file.
	* procfs.c (procfs_init_inferior): Call "gdb_startup_inferior"
	instead of "startup_inferior".  Call "add_thread_silent" after
	"fork_inferior".
	* target.h (target_terminal_init): Move prototype to
	"target/target.h".
	(target_terminal_inferior): Likewise.
	(target_terminal_ours): Likewise.
	* target/target.h (target_terminal_init): New prototype, moved
	from "target.h".
	(target_terminal_inferior): Likewise.
	(target_terminal_ours): Likewise.
	* utils.c (gdb_flush_out_err): New function.

gdb/gdbserver/ChangeLog:
2017-06-07  Sergio Durigan Junior  <sergiodj@redhat.com>
	    Pedro Alves  <palves@redhat.com>

	* Makefile.in (SFILES): Add "nat/fork-inferior.o".
	* configure: Regenerate.
	* configure.srv (srv_linux_obj): Add "fork-child.o" and
	"fork-inferior.o".
	(i[34567]86-*-lynxos*): Likewise.
	(spu*-*-*): Likewise.
	* fork-child.c: New file.
	* linux-low.c: Include "common-inferior.h", "nat/fork-inferior.h"
	and "environ.h".
	(linux_ptrace_fun): New function.
	(linux_create_inferior): Adjust function prototype to reflect
	change on "target.h".  Adjust function code to use
	"fork_inferior".
	(linux_request_interrupt): Delete "signal_pid".
	* lynx-low.c: Include "common-inferior.h" and "nat/fork-inferior.h".
	(lynx_ptrace_fun): New function.
	(lynx_create_inferior): Adjust function prototype to reflect
	change on "target.h".  Adjust function code to use
	"fork_inferior".
	* nto-low.c (nto_create_inferior): Adjust function prototype and
	code to reflect change on "target.h".  Update comments.
	* server.c: Include "common-inferior.h", "nat/fork-inferior.h",
	"common-terminal.h" and "environ.h".
	(terminal_fd): Moved to fork-child.c.
	(old_foreground_pgrp): Likewise.
	(restore_old_foreground_pgrp): Likewise.
	(last_status): Make it global.
	(last_ptid): Likewise.
	(our_environ): New variable.
	(startup_with_shell): Likewise.
	(program_name): Likewise.
	(program_argv): Rename to...
	(program_args): ...this.
	(wrapper_argv): New variable.
	(start_inferior): Delete function.
	(get_exec_wrapper): New function.
	(get_exec_file): Likewise.
	(get_environ): Likewise.
	(prefork_hook): Likewise.
	(post_fork_inferior): Likewise.
	(postfork_hook): Likewise.
	(postfork_child_hook): Likewise.
	(handle_v_run): Update code to deal with arguments coming from the
	remote host.  Update calls from "start_inferior" to
	"create_inferior".
	(captured_main): Likewise.  Initialize environment variable.  Call
	"have_job_control".
	* server.h (post_fork_inferior): New prototype.
	(get_environ): Likewise.
	(last_status): Declare.
	(last_ptid): Likewise.
	(signal_pid): Likewise.
	* spu-low.c: Include "common-inferior.h" and "nat/fork-inferior.h".
	(spu_ptrace_fun): New function.
	(spu_create_inferior): Adjust function prototype to reflect change
	on "target.h".  Adjust function code to use "fork_inferior".
	* target.c (target_terminal_init): New function.
	(target_terminal_inferior): Likewise.
	(target_terminal_ours): Likewise.
	* target.h: Include <vector>.
	(struct target_ops) <create_inferior>: Update prototype.
	(create_inferior): Update macro.
	* utils.c (gdb_flush_out_err): New function.
	* win32-low.c (win32_create_inferior): Adjust function prototype
	and code to reflect change on "target.h".

gdb/testsuite/ChangeLog:
2017-06-07  Sergio Durigan Junior  <sergiodj@redhat.com>

	* gdb.server/non-existing-program.exp: Update regex in order to
	reflect the fact that gdbserver is now using fork_inferior (with a
	shell) to startup the inferior.

13 files changed, 467 insertions, 235 deletions

diff --git a/gdb/gdbserver/ChangeLog b/gdb/gdbserver/ChangeLog
index 840cf79..275f65c 100644
--- a/gdb/gdbserver/ChangeLog
+++ b/gdb/gdbserver/ChangeLog
@@ -1,4 +1,73 @@
 2017-06-07  Sergio Durigan Junior  <sergiodj@redhat.com>
+	    Pedro Alves  <palves@redhat.com>
+
+	* Makefile.in (SFILES): Add "nat/fork-inferior.o".
+	* configure: Regenerate.
+	* configure.srv (srv_linux_obj): Add "fork-child.o" and
+	"fork-inferior.o".
+	(i[34567]86-*-lynxos*): Likewise.
+	(spu*-*-*): Likewise.
+	* fork-child.c: New file.
+	* linux-low.c: Include "common-inferior.h", "nat/fork-inferior.h"
+	and "environ.h".
+	(linux_ptrace_fun): New function.
+	(linux_create_inferior): Adjust function prototype to reflect
+	change on "target.h".  Adjust function code to use
+	"fork_inferior".
+	(linux_request_interrupt): Delete "signal_pid".
+	* lynx-low.c: Include "common-inferior.h" and "nat/fork-inferior.h".
+	(lynx_ptrace_fun): New function.
+	(lynx_create_inferior): Adjust function prototype to reflect
+	change on "target.h".  Adjust function code to use
+	"fork_inferior".
+	* nto-low.c (nto_create_inferior): Adjust function prototype and
+	code to reflect change on "target.h".  Update comments.
+	* server.c: Include "common-inferior.h", "nat/fork-inferior.h",
+	"common-terminal.h" and "environ.h".
+	(terminal_fd): Moved to fork-child.c.
+	(old_foreground_pgrp): Likewise.
+	(restore_old_foreground_pgrp): Likewise.
+	(last_status): Make it global.
+	(last_ptid): Likewise.
+	(our_environ): New variable.
+	(startup_with_shell): Likewise.
+	(program_name): Likewise.
+	(program_argv): Rename to...
+	(program_args): ...this.
+	(wrapper_argv): New variable.
+	(start_inferior): Delete function.
+	(get_exec_wrapper): New function.
+	(get_exec_file): Likewise.
+	(get_environ): Likewise.
+	(prefork_hook): Likewise.
+	(post_fork_inferior): Likewise.
+	(postfork_hook): Likewise.
+	(postfork_child_hook): Likewise.
+	(handle_v_run): Update code to deal with arguments coming from the
+	remote host.  Update calls from "start_inferior" to
+	"create_inferior".
+	(captured_main): Likewise.  Initialize environment variable.  Call
+	"have_job_control".
+	* server.h (post_fork_inferior): New prototype.
+	(get_environ): Likewise.
+	(last_status): Declare.
+	(last_ptid): Likewise.
+	(signal_pid): Likewise.
+	* spu-low.c: Include "common-inferior.h" and "nat/fork-inferior.h".
+	(spu_ptrace_fun): New function.
+	(spu_create_inferior): Adjust function prototype to reflect change
+	on "target.h".  Adjust function code to use "fork_inferior".
+	* target.c (target_terminal_init): New function.
+	(target_terminal_inferior): Likewise.
+	(target_terminal_ours): Likewise.
+	* target.h: Include <vector>.
+	(struct target_ops) <create_inferior>: Update prototype.
+	(create_inferior): Update macro.
+	* utils.c (gdb_flush_out_err): New function.
+	* win32-low.c (win32_create_inferior): Adjust function prototype
+	and code to reflect change on "target.h".
+
+2017-06-07  Sergio Durigan Junior  <sergiodj@redhat.com>
 
 	* inferiors.c (switch_to_thread): New function.
 
diff --git a/gdb/gdbserver/Makefile.in b/gdb/gdbserver/Makefile.in
index d9f55de..834425d 100644
--- a/gdb/gdbserver/Makefile.in
+++ b/gdb/gdbserver/Makefile.in
@@ -218,6 +218,7 @@ SFILES = \
 	$(srcdir)/nat/linux-personality.c \
 	$(srcdir)/nat/mips-linux-watch.c \
 	$(srcdir)/nat/ppc-linux.c \
+	$(srcdir)/nat/fork-inferior.c \
 	$(srcdir)/target/waitstatus.c
 
 DEPFILES = @GDBSERVER_DEPFILES@
diff --git a/gdb/gdbserver/configure.srv b/gdb/gdbserver/configure.srv
index d00d9e2..43f90c9 100644
--- a/gdb/gdbserver/configure.srv
+++ b/gdb/gdbserver/configure.srv
@@ -43,7 +43,7 @@ srv_amd64_linux_xmlfiles="i386/amd64-linux.xml i386/amd64-avx-linux.xml i386/amd
 
 # Linux object files.  This is so we don't have to repeat
 # these files over and over again.
-srv_linux_obj="linux-low.o linux-osdata.o linux-procfs.o linux-ptrace.o linux-waitpid.o linux-personality.o linux-namespaces.o"
+srv_linux_obj="linux-low.o linux-osdata.o linux-procfs.o linux-ptrace.o linux-waitpid.o linux-personality.o linux-namespaces.o fork-child.o fork-inferior.o"
 
 # Input is taken from the "${target}" variable.
 
@@ -131,7 +131,7 @@ case "${target}" in
 			ipa_obj="${ipa_i386_linux_regobj} linux-i386-ipa.o"
 			;;
   i[34567]86-*-lynxos*)	srv_regobj="i386.o"
-			srv_tgtobj="lynx-low.o lynx-i386-low.o"
+			srv_tgtobj="lynx-low.o lynx-i386-low.o fork-child.o fork-inferior.o"
 			srv_xmlfiles="i386/i386.xml"
 			srv_xmlfiles="${srv_xmlfiles} i386/32bit-core.xml"
 			srv_xmlfiles="${srv_xmlfiles} i386/32bit-sse.xml"
@@ -338,7 +338,7 @@ case "${target}" in
 			srv_linux_thread_db=yes
 			;;
   spu*-*-*)		srv_regobj=reg-spu.o
-			srv_tgtobj="spu-low.o"
+			srv_tgtobj="spu-low.o fork-child.o fork-inferior.o"
 			;;
   tic6x-*-uclinux)	srv_regobj="tic6x-c64xp-linux.o"
 			srv_regobj="${srv_regobj} tic6x-c64x-linux.o"
diff --git a/gdb/gdbserver/fork-child.c b/gdb/gdbserver/fork-child.c
new file mode 100644
index 0000000..a1a8ff1
--- /dev/null
+++ b/gdb/gdbserver/fork-child.c
@@ -0,0 +1,113 @@
+/* Fork a Unix child process, and set up to debug it, for GDBserver.
+   Copyright (C) 1989-2017 Free Software Foundation, Inc.
+
+   This file is part of GDB.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+#include "server.h"
+#include "job-control.h"
+#include "nat/fork-inferior.h"
+
+#ifdef SIGTTOU
+/* A file descriptor for the controlling terminal.  */
+static int terminal_fd;
+
+/* TERMINAL_FD's original foreground group.  */
+static pid_t old_foreground_pgrp;
+
+/* Hand back terminal ownership to the original foreground group.  */
+
+static void
+restore_old_foreground_pgrp (void)
+{
+  tcsetpgrp (terminal_fd, old_foreground_pgrp);
+}
+#endif
+
+/* See nat/fork-inferior.h.  */
+
+void
+prefork_hook (const char *args)
+{
+  if (debug_threads)
+    {
+      debug_printf ("args: %s\n", args);
+      debug_flush ();
+    }
+
+#ifdef SIGTTOU
+  signal (SIGTTOU, SIG_DFL);
+  signal (SIGTTIN, SIG_DFL);
+#endif
+
+  /* Clear this so the backend doesn't get confused, thinking
+     CONT_THREAD died, and it needs to resume all threads.  */
+  cont_thread = null_ptid;
+}
+
+/* See nat/fork-inferior.h.  */
+
+void
+postfork_hook (pid_t pid)
+{
+}
+
+/* See nat/fork-inferior.h.  */
+
+void
+postfork_child_hook ()
+{
+  /* This is set to the result of setpgrp, which if vforked, will be
+     visible to you in the parent process.  It's only used by humans
+     for debugging.  */
+  static int debug_setpgrp = 657473;
+
+  debug_setpgrp = gdb_setpgid ();
+  if (debug_setpgrp == -1)
+    perror (_("setpgrp failed in child"));
+}
+
+/* See nat/fork-inferior.h.  */
+
+void
+gdb_flush_out_err ()
+{
+  fflush (stdout);
+  fflush (stderr);
+}
+
+/* See server.h.  */
+
+void
+post_fork_inferior (int pid, const char *program)
+{
+#ifdef SIGTTOU
+  signal (SIGTTOU, SIG_IGN);
+  signal (SIGTTIN, SIG_IGN);
+  terminal_fd = fileno (stderr);
+  old_foreground_pgrp = tcgetpgrp (terminal_fd);
+  tcsetpgrp (terminal_fd, pid);
+  atexit (restore_old_foreground_pgrp);
+#endif
+
+  startup_inferior (pid, START_INFERIOR_TRAPS_EXPECTED,
+		    &last_status, &last_ptid);
+  current_thread->last_resume_kind = resume_stop;
+  current_thread->last_status = last_status;
+  signal_pid = pid;
+  target_post_create_inferior ();
+  fprintf (stderr, "Process %s created; pid = %d\n", program, pid);
+  fflush (stderr);
+}
diff --git a/gdb/gdbserver/linux-low.c b/gdb/gdbserver/linux-low.c
index ea3c81b..7fbf744 100644
--- a/gdb/gdbserver/linux-low.c
+++ b/gdb/gdbserver/linux-low.c
@@ -47,6 +47,9 @@
 #include "tracepoint.h"
 #include "hostio.h"
 #include <inttypes.h>
+#include "common-inferior.h"
+#include "nat/fork-inferior.h"
+#include "environ.h"
 #ifndef ELFMAG0
 /* Don't include <linux/elf.h> here.  If it got included by gdb_proc_service.h
    then ELFMAG0 will have been defined.  If it didn't get included by
@@ -946,59 +949,57 @@ add_lwp (ptid_t ptid)
   return lwp;
 }
 
+/* Callback to be used when calling fork_inferior, responsible for
+   actually initiating the tracing of the inferior.  */
+
+static void
+linux_ptrace_fun ()
+{
+  if (ptrace (PTRACE_TRACEME, 0, (PTRACE_TYPE_ARG3) 0,
+	      (PTRACE_TYPE_ARG4) 0) < 0)
+    trace_start_error_with_name ("ptrace");
+
+  if (setpgid (0, 0) < 0)
+    trace_start_error_with_name ("setpgid");
+
+  /* If GDBserver is connected to gdb via stdio, redirect the inferior's
+     stdout to stderr so that inferior i/o doesn't corrupt the connection.
+     Also, redirect stdin to /dev/null.  */
+  if (remote_connection_is_stdio ())
+    {
+      if (close (0) < 0)
+	trace_start_error_with_name ("close");
+      if (open ("/dev/null", O_RDONLY) < 0)
+	trace_start_error_with_name ("open");
+      if (dup2 (2, 1) < 0)
+	trace_start_error_with_name ("dup2");
+      if (write (2, "stdin/stdout redirected\n",
+		 sizeof ("stdin/stdout redirected\n") - 1) < 0)
+	{
+	  /* Errors ignored.  */;
+	}
+    }
+}
+
 /* Start an inferior process and returns its pid.
-   ALLARGS is a vector of program-name and args. */
+   PROGRAM is the name of the program to be started, and PROGRAM_ARGS
+   are its arguments.  */
 
 static int
-linux_create_inferior (char *program, char **allargs)
+linux_create_inferior (const char *program,
+		       const std::vector<char *> &program_args)
 {
   struct lwp_info *new_lwp;
   int pid;
   ptid_t ptid;
   struct cleanup *restore_personality
     = maybe_disable_address_space_randomization (disable_randomization);
+  std::string str_program_args = stringify_argv (program_args);
 
-#if defined(__UCLIBC__) && defined(HAS_NOMMU)
-  pid = vfork ();
-#else
-  pid = fork ();
-#endif
-  if (pid < 0)
-    perror_with_name ("fork");
-
-  if (pid == 0)
-    {
-      close_most_fds ();
-      ptrace (PTRACE_TRACEME, 0, (PTRACE_TYPE_ARG3) 0, (PTRACE_TYPE_ARG4) 0);
-
-      setpgid (0, 0);
-
-      /* If gdbserver is connected to gdb via stdio, redirect the inferior's
-	 stdout to stderr so that inferior i/o doesn't corrupt the connection.
-	 Also, redirect stdin to /dev/null.  */
-      if (remote_connection_is_stdio ())
-	{
-	  close (0);
-	  open ("/dev/null", O_RDONLY);
-	  dup2 (2, 1);
-	  if (write (2, "stdin/stdout redirected\n",
-		     sizeof ("stdin/stdout redirected\n") - 1) < 0)
-	    {
-	      /* Errors ignored.  */;
-	    }
-	}
-
-      restore_original_signals_state ();
-
-      execv (program, allargs);
-      if (errno == ENOENT)
-	execvp (program, allargs);
-
-      fprintf (stderr, "Cannot exec %s: %s.\n", program,
-	       strerror (errno));
-      fflush (stderr);
-      _exit (0177);
-    }
+  pid = fork_inferior (program,
+		       str_program_args.c_str (),
+		       environ_vector (get_environ ()), linux_ptrace_fun,
+		       NULL, NULL, NULL, NULL);
 
   do_cleanups (restore_personality);
 
@@ -1008,6 +1009,8 @@ linux_create_inferior (char *program, char **allargs)
   new_lwp = add_lwp (ptid);
   new_lwp->must_set_ptrace_flags = 1;
 
+  post_fork_inferior (pid, program);
+
   return pid;
 }
 
@@ -6055,8 +6058,6 @@ linux_look_up_symbols (void)
 static void
 linux_request_interrupt (void)
 {
-  extern unsigned long signal_pid;
-
   /* Send a SIGINT to the process group.  This acts just like the user
      typed a ^C on the controlling terminal.  */
   kill (-signal_pid, SIGINT);
diff --git a/gdb/gdbserver/lynx-low.c b/gdb/gdbserver/lynx-low.c
index d300aae..35160d6 100644
--- a/gdb/gdbserver/lynx-low.c
+++ b/gdb/gdbserver/lynx-low.c
@@ -28,6 +28,8 @@
 #include "gdb_wait.h"
 #include <signal.h>
 #include "filestuff.h"
+#include "common-inferior.h"
+#include "nat/fork-inferior.h"
 
 int using_threads = 1;
 
@@ -224,36 +226,43 @@ lynx_add_process (int pid, int attached)
   return proc;
 }
 
+/* Callback used by fork_inferior to start tracing the inferior.  */
+
+static void
+lynx_ptrace_fun ()
+{
+  int pgrp;
+
+  /* Switch child to its own process group so that signals won't
+     directly affect GDBserver. */
+  pgrp = getpid();
+  if (pgrp < 0)
+    trace_start_error_with_name ("pgrp");
+  if (setpgid (0, pgrp) < 0)
+    trace_start_error_with_name ("setpgid");
+  if (ioctl (0, TIOCSPGRP, &pgrp) < 0)
+    trace_start_error_with_name ("ioctl");
+  if (lynx_ptrace (PTRACE_TRACEME, null_ptid, 0, 0, 0) < 0)
+    trace_start_error_with_name ("lynx_ptrace");
+}
+
 /* Implement the create_inferior method of the target_ops vector.  */
 
 static int
-lynx_create_inferior (char *program, char **allargs)
+lynx_create_inferior (const char *program,
+		      const std::vector<char *> &program_args)
 {
   int pid;
+  std::string str_program_args = stringify_argv (program_args);
 
   lynx_debug ("lynx_create_inferior ()");
 
-  pid = fork ();
-  if (pid < 0)
-    perror_with_name ("fork");
+  pid = fork_inferior (program,
+		       str_program_args.c_str (),
+		       environ_vector (get_environ ()), lynx_ptrace_fun,
+		       NULL, NULL, NULL, NULL);
 
-  if (pid == 0)
-    {
-      int pgrp;
-
-      close_most_fds ();
-
-      /* Switch child to its own process group so that signals won't
-         directly affect gdbserver. */
-      pgrp = getpid();
-      setpgid (0, pgrp);
-      ioctl (0, TIOCSPGRP, &pgrp);
-      lynx_ptrace (PTRACE_TRACEME, null_ptid, 0, 0, 0);
-      execv (program, allargs);
-      fprintf (stderr, "Cannot exec %s: %s.\n", program, strerror (errno));
-      fflush (stderr);
-      _exit (0177);
-    }
+  post_fork_inferior (pid, program);
 
   lynx_add_process (pid, 0);
   /* Do not add the process thread just yet, as we do not know its tid.
diff --git a/gdb/gdbserver/nto-low.c b/gdb/gdbserver/nto-low.c
index 6229b4c..a5f1543 100644
--- a/gdb/gdbserver/nto-low.c
+++ b/gdb/gdbserver/nto-low.c
@@ -347,14 +347,17 @@ nto_read_auxv_from_initial_stack (CORE_ADDR initial_stack,
   return len_read;
 }
 
-/* Start inferior specified by PROGRAM passing arguments ALLARGS.  */
+/* Start inferior specified by PROGRAM, using PROGRAM_ARGS as its
+   arguments.  */
 
 static int
-nto_create_inferior (char *program, char **allargs)
+nto_create_inferior (const char *program,
+		     const std::vector<char *> &program_args)
 {
   struct inheritance inherit;
   pid_t pid;
   sigset_t set;
+  std::string str_program_args = stringify_argv (program_args);
 
   TRACE ("%s %s\n", __func__, program);
   /* Clear any pending SIGUSR1's but keep the behavior the same.  */
@@ -367,7 +370,8 @@ nto_create_inferior (char *program, char **allargs)
   memset (&inherit, 0, sizeof (inherit));
   inherit.flags |= SPAWN_SETGROUP | SPAWN_HOLD;
   inherit.pgroup = SPAWN_NEWPGROUP;
-  pid = spawnp (program, 0, NULL, &inherit, allargs, 0);
+  pid = spawnp (program, 0, NULL, &inherit,
+		(char *) str_program_args.c_str (), 0);
   sigprocmask (SIG_BLOCK, &set, NULL);
 
   if (pid == -1)
diff --git a/gdb/gdbserver/server.c b/gdb/gdbserver/server.c
index 69fcab1..3ab042d 100644
--- a/gdb/gdbserver/server.c
+++ b/gdb/gdbserver/server.c
@@ -36,6 +36,19 @@
 #include "dll.h"
 #include "hostio.h"
 #include <vector>
+#include "common-inferior.h"
+#include "job-control.h"
+#include "environ.h"
+
+/* The environment to pass to the inferior when creating it.  */
+
+struct gdb_environ *our_environ = NULL;
+
+/* Start the inferior using a shell.  */
+
+/* We always try to start the inferior using a shell.  */
+
+int startup_with_shell = 1;
 
 /* The thread set with an `Hc' packet.  `Hc' is deprecated in favor of
    `vCont'.  Note the multi-process extensions made `vCont' a
@@ -79,8 +92,9 @@ static int vCont_supported;
    space randomization feature before starting an inferior.  */
 int disable_randomization = 1;
 
-static std::vector<char *> program_argv;
-static std::vector<char *> wrapper_argv;
+static char *program_name = NULL;
+static std::vector<char *> program_args;
+static std::string wrapper_argv;
 
 int pass_signals[GDB_SIGNAL_LAST];
 int program_signals[GDB_SIGNAL_LAST];
@@ -93,22 +107,6 @@ int program_signals_p;
 
 unsigned long signal_pid;
 
-#ifdef SIGTTOU
-/* A file descriptor for the controlling terminal.  */
-int terminal_fd;
-
-/* TERMINAL_FD's original foreground group.  */
-pid_t old_foreground_pgrp;
-
-/* Hand back terminal ownership to the original foreground group.  */
-
-static void
-restore_old_foreground_pgrp (void)
-{
-  tcsetpgrp (terminal_fd, old_foreground_pgrp);
-}
-#endif
-
 /* Set if you want to disable optional thread related packets support
    in gdbserver, for the sake of testing GDB against stubs that don't
    support them.  */
@@ -118,8 +116,8 @@ int disable_packet_qC;
 int disable_packet_qfThreadInfo;
 
 /* Last status reported to GDB.  */
-static struct target_waitstatus last_status;
-static ptid_t last_ptid;
+struct target_waitstatus last_status;
+ptid_t last_ptid;
 
 char *own_buf;
 static unsigned char *mem_buf;
@@ -238,94 +236,31 @@ target_running (void)
   return get_first_thread () != NULL;
 }
 
-static int
-start_inferior (char **argv)
-{
-  std::vector<char *> new_argv;
-
-  if (!wrapper_argv.empty ())
-    new_argv.insert (new_argv.begin (),
-		     wrapper_argv.begin (),
-		     wrapper_argv.end ());
-
-  for (int i = 0; argv[i] != NULL; ++i)
-    new_argv.push_back (argv[i]);
-
-  new_argv.push_back (NULL);
+/* See common/common-inferior.h.  */
 
-  if (debug_threads)
-    {
-      for (int i = 0; i < new_argv.size (); ++i)
-	debug_printf ("new_argv[%d] = \"%s\"\n", i, new_argv[i]);
-      debug_flush ();
-    }
-
-#ifdef SIGTTOU
-  signal (SIGTTOU, SIG_DFL);
-  signal (SIGTTIN, SIG_DFL);
-#endif
-
-  signal_pid = create_inferior (new_argv[0], &new_argv[0]);
-
-  /* FIXME: we don't actually know at this point that the create
-     actually succeeded.  We won't know that until we wait.  */
-  fprintf (stderr, "Process %s created; pid = %ld\n", argv[0],
-	   signal_pid);
-  fflush (stderr);
-
-#ifdef SIGTTOU
-  signal (SIGTTOU, SIG_IGN);
-  signal (SIGTTIN, SIG_IGN);
-  terminal_fd = fileno (stderr);
-  old_foreground_pgrp = tcgetpgrp (terminal_fd);
-  tcsetpgrp (terminal_fd, signal_pid);
-  atexit (restore_old_foreground_pgrp);
-#endif
-
-  if (!wrapper_argv.empty ())
-    {
-      ptid_t ptid = pid_to_ptid (signal_pid);
-
-      last_ptid = mywait (pid_to_ptid (signal_pid), &last_status, 0, 0);
-
-      if (last_status.kind == TARGET_WAITKIND_STOPPED)
-	{
-	  do
-	    {
-	      target_continue_no_signal (ptid);
+const char *
+get_exec_wrapper ()
+{
+  return !wrapper_argv.empty () ? wrapper_argv.c_str () : NULL;
+}
 
-	      last_ptid = mywait (pid_to_ptid (signal_pid), &last_status, 0, 0);
-	      if (last_status.kind != TARGET_WAITKIND_STOPPED)
-		break;
+/* See common/common-inferior.h.  */
 
-	      current_thread->last_resume_kind = resume_stop;
-	      current_thread->last_status = last_status;
-	    }
-	  while (last_status.value.sig != GDB_SIGNAL_TRAP);
-	}
-      target_post_create_inferior ();
-      return signal_pid;
-    }
+char *
+get_exec_file (int err)
+{
+  if (err && program_name == NULL)
+    error (_("No executable file specified."));
 
-  /* Wait till we are at 1st instruction in program, return new pid
-     (assuming success).  */
-  last_ptid = mywait (pid_to_ptid (signal_pid), &last_status, 0, 0);
+  return program_name;
+}
 
-  /* At this point, the target process, if it exits, is stopped.  Do not call
-     the function target_post_create_inferior if the process has already
-     exited, as the target implementation of the routine may rely on the
-     process being live. */
-  if (last_status.kind != TARGET_WAITKIND_EXITED
-      && last_status.kind != TARGET_WAITKIND_SIGNALLED)
-    {
-      target_post_create_inferior ();
-      current_thread->last_resume_kind = resume_stop;
-      current_thread->last_status = last_status;
-    }
-  else
-    target_mourn_inferior (last_ptid);
+/* See server.h.  */
 
-  return signal_pid;
+struct gdb_environ *
+get_environ ()
+{
+  return our_environ;
 }
 
 static int
@@ -2848,6 +2783,7 @@ handle_v_run (char *own_buf)
 {
   char *p, *next_p;
   std::vector<char *> new_argv;
+  char *new_program_name = NULL;
   int i, new_argc;
 
   new_argc = 0;
@@ -2866,42 +2802,94 @@ handle_v_run (char *own_buf)
       if (i == 0 && p == next_p)
 	{
 	  /* No program specified.  */
-	  new_argv.push_back (NULL);
+	  new_program_name = NULL;
+	}
+      else if (p == next_p)
+	{
+	  /* Empty argument.  */
+	  new_argv.push_back (xstrdup ("''"));
 	}
       else
 	{
 	  size_t len = (next_p - p) / 2;
+	  /* ARG is the unquoted argument received via the RSP.  */
 	  char *arg = (char *) xmalloc (len + 1);
+	  /* FULL_ARGS will contain the quoted version of ARG.  */
+	  char *full_arg = (char *) xmalloc ((len + 1) * 2);
+	  /* These are pointers used to navigate the strings above.  */
+	  char *tmp_arg = arg;
+	  char *tmp_full_arg = full_arg;
+	  int need_quote = 0;
 
 	  hex2bin (p, (gdb_byte *) arg, len);
 	  arg[len] = '\0';
-	  new_argv.push_back (arg);
-	}
 
+	  while (*tmp_arg != '\0')
+	    {
+	      switch (*tmp_arg)
+		{
+		case '\n':
+		  /* Quote \n.  */
+		  *tmp_full_arg = '\'';
+		  ++tmp_full_arg;
+		  need_quote = 1;
+		  break;
+
+		case '\'':
+		  /* Quote single quote.  */
+		  *tmp_full_arg = '\\';
+		  ++tmp_full_arg;
+		  break;
+
+		default:
+		  break;
+		}
+
+	      *tmp_full_arg = *tmp_arg;
+	      ++tmp_full_arg;
+	      ++tmp_arg;
+	    }
+
+	  if (need_quote)
+	    *tmp_full_arg++ = '\'';
+
+	  /* Finish FULL_ARG and push it into the vector containing
+	     the argv.  */
+	  *tmp_full_arg = '\0';
+	  if (i == 0)
+	    new_program_name = full_arg;
+	  else
+	    new_argv.push_back (full_arg);
+	  xfree (arg);
+	}
       if (*next_p)
 	next_p++;
     }
   new_argv.push_back (NULL);
 
-  if (new_argv[0] == NULL)
+  if (new_program_name == NULL)
     {
       /* GDB didn't specify a program to run.  Use the program from the
 	 last run with the new argument list.  */
-      if (program_argv.empty ())
+      if (program_name == NULL)
 	{
 	  write_enn (own_buf);
 	  free_vector_argv (new_argv);
 	  return 0;
 	}
-
-      new_argv.push_back (xstrdup (program_argv[0]));
+    }
+  else
+    {
+      xfree (program_name);
+      program_name = new_program_name;
     }
 
   /* Free the old argv and install the new one.  */
-  free_vector_argv (program_argv);
-  program_argv = new_argv;
+  free_vector_argv (program_args);
+  program_args = new_argv;
+
+  create_inferior (program_name, program_args);
 
-  start_inferior (&program_argv[0]);
   if (last_status.kind == TARGET_WAITKIND_STOPPED)
     {
       prepare_resume_reply (own_buf, last_ptid, &last_status);
@@ -3527,10 +3515,17 @@ captured_main (int argc, char *argv[])
 	  tmp = next_arg;
 	  while (*next_arg != NULL && strcmp (*next_arg, "--") != 0)
 	    {
-	      wrapper_argv.push_back (*next_arg);
+	      wrapper_argv += *next_arg;
+	      wrapper_argv += ' ';
 	      next_arg++;
 	    }
 
+	  if (!wrapper_argv.empty ())
+	    {
+	      /* Erase the last whitespace.  */
+	      wrapper_argv.erase (wrapper_argv.end () - 1);
+	    }
+
 	  if (next_arg == tmp || *next_arg == NULL)
 	    {
 	      gdbserver_usage (stderr);
@@ -3666,8 +3661,13 @@ captured_main (int argc, char *argv[])
       exit (1);
     }
 
+  /* Gather information about the environment.  */
+  our_environ = make_environ ();
+  init_environ (our_environ);
+
   initialize_async_io ();
   initialize_low ();
+  have_job_control ();
   initialize_event_loop ();
   if (target_supports_tracepoints ())
     initialize_tracepoint ();
@@ -3681,12 +3681,13 @@ captured_main (int argc, char *argv[])
       int i, n;
 
       n = argc - (next_arg - argv);
-      for (i = 0; i < n; i++)
-	program_argv.push_back (xstrdup (next_arg[i]));
-      program_argv.push_back (NULL);
+      program_name = xstrdup (next_arg[0]);
+      for (i = 1; i < n; i++)
+	program_args.push_back (xstrdup (next_arg[i]));
+      program_args.push_back (NULL);
 
       /* Wait till we are at first instruction in program.  */
-      start_inferior (&program_argv[0]);
+      create_inferior (program_name, program_args);
 
       /* We are now (hopefully) stopped at the first instruction of
 	 the target process.  This assumes that the target process was
@@ -4301,9 +4302,10 @@ process_serial_event (void)
 	  fprintf (stderr, "GDBserver restarting\n");
 
 	  /* Wait till we are at 1st instruction in prog.  */
-	  if (!program_argv.empty ())
+	  if (program_name != NULL)
 	    {
-	      start_inferior (&program_argv[0]);
+	      create_inferior (program_name, program_args);
+
 	      if (last_status.kind == TARGET_WAITKIND_STOPPED)
 		{
 		  /* Stopped at the first instruction of the target
diff --git a/gdb/gdbserver/server.h b/gdb/gdbserver/server.h
index d5fee38..4de4244 100644
--- a/gdb/gdbserver/server.h
+++ b/gdb/gdbserver/server.h
@@ -148,4 +148,18 @@ extern int in_queued_stop_replies (ptid_t ptid);
 /* Definition for any syscall, used for unfiltered syscall reporting.  */
 #define ANY_SYSCALL (-2)
 
+/* After fork_inferior has been called, we need to adjust a few
+   signals and call startup_inferior to start the inferior and consume
+   its first events.  This is done here.  PID is the pid of the new
+   inferior and PROGRAM is its name.  */
+extern void post_fork_inferior (int pid, const char *program);
+
+/* Get the 'struct gdb_environ *' being used in the current
+   session.  */
+extern struct gdb_environ *get_environ ();
+
+extern target_waitstatus last_status;
+extern ptid_t last_ptid;
+extern unsigned long signal_pid;
+
 #endif /* SERVER_H */
diff --git a/gdb/gdbserver/spu-low.c b/gdb/gdbserver/spu-low.c
index 117b871..0f770a0 100644
--- a/gdb/gdbserver/spu-low.c
+++ b/gdb/gdbserver/spu-low.c
@@ -27,6 +27,7 @@
 #include <sys/syscall.h>
 #include "filestuff.h"
 #include "hostio.h"
+#include "nat/fork-inferior.h"
 
 /* Some older glibc versions do not define this.  */
 #ifndef __WNOTHREAD
@@ -261,36 +262,37 @@ spu_proc_xfer_spu (const char *annex, unsigned char *readbuf,
   return ret;
 }
 
+/* Callback to be used when calling fork_inferior, responsible for
+   actually initiating the tracing of the inferior.  */
+
+static void
+spu_ptrace_fun ()
+{
+  if (ptrace (PTRACE_TRACEME, 0, 0, 0) < 0)
+    trace_start_error_with_name ("ptrace");
+  if (setpgid (0, 0) < 0)
+    trace_start_error_with_name ("setpgid");
+}
 
 /* Start an inferior process and returns its pid.
-   ALLARGS is a vector of program-name and args. */
+   PROGRAM is the name of the program to be started, and PROGRAM_ARGS
+   are its arguments.  */
+
 static int
-spu_create_inferior (char *program, char **allargs)
+spu_create_inferior (const char *program,
+		     const std::vector<char *> &program_argv)
 {
   int pid;
   ptid_t ptid;
   struct process_info *proc;
+  std::string str_program_args = stringify_argv (program_args);
 
-  pid = fork ();
-  if (pid < 0)
-    perror_with_name ("fork");
-
-  if (pid == 0)
-    {
-      close_most_fds ();
-      ptrace (PTRACE_TRACEME, 0, 0, 0);
-
-      setpgid (0, 0);
-
-      execv (program, allargs);
-      if (errno == ENOENT)
-	execvp (program, allargs);
+  pid = fork_inferior (program,
+		       str_program_args.c_str (),
+		       environ_vector (get_environ ()), spu_ptrace_fun,
+		       NULL, NULL, NULL, NULL);
 
-      fprintf (stderr, "Cannot exec %s: %s.\n", program,
-	       strerror (errno));
-      fflush (stderr);
-      _exit (0177);
-    }
+  post_fork_inferior (pid, program);
 
   proc = add_process (pid, 0);
   proc->tdesc = tdesc_spu;
diff --git a/gdb/gdbserver/target.c b/gdb/gdbserver/target.c
index fda72e8..7526463 100644
--- a/gdb/gdbserver/target.c
+++ b/gdb/gdbserver/target.c
@@ -387,3 +387,30 @@ default_breakpoint_kind_from_pc (CORE_ADDR *pcptr)
   (*the_target->sw_breakpoint_from_kind) (0, &size);
   return size;
 }
+
+/* See target/target.h.  */
+
+void
+target_terminal_init ()
+{
+  /* Placeholder needed because of fork_inferior.  Not necessary on
+     GDBserver.  */
+}
+
+/* See target/target.h.  */
+
+void
+target_terminal_inferior ()
+{
+  /* Placeholder needed because of fork_inferior.  Not necessary on
+     GDBserver.  */
+}
+
+/* See target/target.h.  */
+
+void
+target_terminal_ours ()
+{
+  /* Placeholder needed because of fork_inferior.  Not necessary on
+     GDBserver.  */
+}
diff --git a/gdb/gdbserver/target.h b/gdb/gdbserver/target.h
index 3cc2bc4..be89258 100644
--- a/gdb/gdbserver/target.h
+++ b/gdb/gdbserver/target.h
@@ -28,6 +28,7 @@
 #include "target/waitstatus.h"
 #include "mem-break.h"
 #include "btrace-common.h"
+#include <vector>
 
 struct emit_ops;
 struct buffer;
@@ -67,13 +68,13 @@ struct target_ops
   /* Start a new process.
 
      PROGRAM is a path to the program to execute.
-     ARGS is a standard NULL-terminated array of arguments,
-     to be passed to the inferior as ``argv''.
+     PROGRAM_ARGS is a standard NULL-terminated array of arguments,
+     to be passed to the inferior as ``argv'' (along with PROGRAM).
 
      Returns the new PID on success, -1 on failure.  Registers the new
      process with the process list.  */
-
-  int (*create_inferior) (char *program, char **args);
+  int (*create_inferior) (const char *program,
+			  const std::vector<char *> &program_args);
 
   /* Do additional setup after a new process is created, including
      exec-wrapper completion.  */
@@ -480,8 +481,8 @@ extern struct target_ops *the_target;
 
 void set_target_ops (struct target_ops *);
 
-#define create_inferior(program, args) \
-  (*the_target->create_inferior) (program, args)
+#define create_inferior(program, program_args)	\
+  (*the_target->create_inferior) (program, program_args)
 
 #define target_post_create_inferior()			 \
   do							 \
diff --git a/gdb/gdbserver/win32-low.c b/gdb/gdbserver/win32-low.c
index 7b09f4b..88f6911 100644
--- a/gdb/gdbserver/win32-low.c
+++ b/gdb/gdbserver/win32-low.c
@@ -608,13 +608,13 @@ create_process (const char *program, char *args,
 }
 
 /* Start a new process.
-   PROGRAM is a path to the program to execute.
-   ARGS is a standard NULL-terminated array of arguments,
-   to be passed to the inferior as ``argv''.
+   PROGRAM is the program name.
+   PROGRAM_ARGS is the vector containing the inferior's args.
    Returns the new PID on success, -1 on failure.  Registers the new
    process with the process list.  */
 static int
-win32_create_inferior (char *program, char **program_args)
+win32_create_inferior (const char *program,
+		       const std::vector<char *> &program_args)
 {
 #ifndef USE_WIN32API
   char real_path[PATH_MAX];
@@ -622,11 +622,12 @@ win32_create_inferior (char *program, char **program_args)
 #endif
   BOOL ret;
   DWORD flags;
-  char *args;
   int argslen;
   int argc;
   PROCESS_INFORMATION pi;
   DWORD err;
+  std::string str_program_args = stringify_argv (program_args);
+  char *args = (char *) str_program_args.c_str ();
 
   /* win32_wait needs to know we're not attaching.  */
   attaching = 0;
@@ -652,18 +653,6 @@ win32_create_inferior (char *program, char **program_args)
   program = real_path;
 #endif
 
-  argslen = 1;
-  for (argc = 1; program_args[argc]; argc++)
-    argslen += strlen (program_args[argc]) + 1;
-  args = (char *) alloca (argslen);
-  args[0] = '\0';
-  for (argc = 1; program_args[argc]; argc++)
-    {
-      /* FIXME: Can we do better about quoting?  How does Cygwin
-	 handle this?  */
-      strcat (args, " ");
-      strcat (args, program_args[argc]);
-    }
   OUTMSG2 (("Command line is \"%s\"\n", args));
 
 #ifdef CREATE_NEW_PROCESS_GROUP