diff mbox

[v7,3/4] Share fork_inferior et al with gdbserver

Message ID 20170604221803.17649-4-sergiodj@redhat.com
State New
Headers show

Commit Message

Sergio Durigan Junior June 4, 2017, 10:18 p.m. UTC
This is the most important (and the biggest, sorry) patch of the
series.  It moves fork_inferior from gdb/fork-child.c to
common/common-fork-child.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:
yyyy-mm-dd  Sergio Durigan Junior  <sergiodj@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.
	(trace_start_error): Moved from "fork-child.c".
	(trace_start_error_with_name): Likewise.
	* 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".
	* common/common-utils.h (gdb_flush_out_err): New prototype.
	(stringify_argv): Likewise.
	(trace_start_error): Likewise.
	(trace_start_error_with_name): Likewise.
	* 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.
	* 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:
yyyy-mm-dd  Sergio Durigan Junior  <sergiodj@redhat.com>

	* Makefile.in (SFILES): Add "nat/fork-inferior.o".
	* configure: Regenerate.
	* configure.ac: Adding object file related to safe_strerror to
	IPA_DEPFILES.
	* configure.srv (srv_linux_obj): Add "fork-inferior.o".
	(i[34567]86-*-lynxos*): Likewise.
	(spu*-*-*): Likewise.
	* 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".
	* 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".
	(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: Include <vector>.
	(post_fork_inferior): New prototype.
	(get_environ): 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:
2017-01-17  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.
---
 gdb/Makefile.in                                   |   2 +
 gdb/common/common-inferior.h                      |  33 ++
 gdb/common/common-utils.c                         |  48 ++
 gdb/common/common-utils.h                         |  20 +
 gdb/configure.nat                                 |   8 +-
 gdb/corefile.c                                    |   4 +-
 gdb/darwin-nat.c                                  |  16 +-
 gdb/fork-child.c                                  | 629 +++-------------------
 gdb/gdbserver/Makefile.in                         |   1 +
 gdb/gdbserver/configure                           |   4 +-
 gdb/gdbserver/configure.ac                        |   4 +-
 gdb/gdbserver/configure.srv                       |   6 +-
 gdb/gdbserver/linux-low.c                         |  89 +--
 gdb/gdbserver/lynx-low.c                          |  51 +-
 gdb/gdbserver/nto-low.c                           |  10 +-
 gdb/gdbserver/server.c                            | 250 ++++++---
 gdb/gdbserver/server.h                            |  16 +
 gdb/gdbserver/spu-low.c                           |  45 +-
 gdb/gdbserver/target.c                            |  27 +
 gdb/gdbserver/target.h                            |  13 +-
 gdb/gdbserver/utils.c                             |   9 +
 gdb/gdbserver/win32-low.c                         |  23 +-
 gdb/gnu-nat.c                                     |   8 +-
 gdb/inf-ptrace.c                                  |  15 +-
 gdb/inferior.h                                    |  33 +-
 gdb/nat/fork-inferior.c                           | 569 +++++++++++++++++++
 gdb/nat/fork-inferior.h                           |  90 ++++
 gdb/procfs.c                                      |   7 +-
 gdb/target.h                                      |  18 +-
 gdb/target/target.h                               |  14 +
 gdb/testsuite/gdb.server/non-existing-program.exp |  12 +-
 gdb/utils.c                                       |   9 +
 32 files changed, 1261 insertions(+), 822 deletions(-)
 create mode 100644 gdb/common/common-inferior.h
 create mode 100644 gdb/nat/fork-inferior.c
 create mode 100644 gdb/nat/fork-inferior.h

Comments

Yao Qi June 8, 2017, 4:40 p.m. UTC | #1
Sergio Durigan Junior <sergiodj@redhat.com> writes:

Hi Sergio,
This patch causes a lot of test fails on AArch64, shown by buildbot,
https://gdb-build.sergiodj.net/builders/Ubuntu-AArch64-native-gdbserver-m64/builds/2099
However, other builders with GDBserver look fine.  I haven't triage them yet.
Sergio Durigan Junior June 8, 2017, 6:49 p.m. UTC | #2
On Thursday, June 08 2017, Yao Qi wrote:

> Sergio Durigan Junior <sergiodj@redhat.com> writes:
>
> Hi Sergio,
> This patch causes a lot of test fails on AArch64, shown by buildbot,
> https://gdb-build.sergiodj.net/builders/Ubuntu-AArch64-native-gdbserver-m64/builds/2099
> However, other builders with GDBserver look fine.  I haven't triage them yet.

Hi Yao,

Thanks for the message.  I'll look at these right away.
Simon Marchi June 21, 2017, 5:01 p.m. UTC | #3
On 2017-06-05 00:18, Sergio Durigan Junior wrote:
> This is the most important (and the biggest, sorry) patch of the
> series.  It moves fork_inferior from gdb/fork-child.c to
> common/common-fork-child.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.

I just started to play with GDB on macOS, and it seems currently broken, 
a bisect pointed me to this commit 
(2090129c36c7e582943b7d300968d19b46160d84).

When trying to run/start, I get this:

Temporary breakpoint 1 at 0x100000fb6: file /Users/simark/test.c, line 
2.
Starting program: /Users/simark/test
/Users/simark/src/binutils-gdb/gdb/darwin-nat.c:383: internal-error: 
void darwin_check_new_threads(struct inferior *): Assertion `tp' failed.
A problem internal to GDB has been detected,
further debugging may prove unreliable.
Quit this debugging session? (y or n)

I haven't investigated yet, but I thought I'd share the information in 
case somebody is interested .

I am CCing Tristan because he's the last person who made fixes to keep 
the macOS support somewhat working (thanks!).  If you could at least 
tell if you get the same error, it would be helpful.

Thanks,

Simon
Sergio Durigan Junior June 21, 2017, 5:19 p.m. UTC | #4
On Wednesday, June 21 2017, Simon Marchi wrote:

> On 2017-06-05 00:18, Sergio Durigan Junior wrote:
>> This is the most important (and the biggest, sorry) patch of the
>> series.  It moves fork_inferior from gdb/fork-child.c to
>> common/common-fork-child.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.
>
> I just started to play with GDB on macOS, and it seems currently
> broken, a bisect pointed me to this commit
> (2090129c36c7e582943b7d300968d19b46160d84).
>
> When trying to run/start, I get this:
>
> Temporary breakpoint 1 at 0x100000fb6: file /Users/simark/test.c, line
> 2.
> Starting program: /Users/simark/test
> /Users/simark/src/binutils-gdb/gdb/darwin-nat.c:383: internal-error:
> void darwin_check_new_threads(struct inferior *): Assertion `tp'
> failed.
> A problem internal to GDB has been detected,
> further debugging may prove unreliable.
> Quit this debugging session? (y or n)
>
> I haven't investigated yet, but I thought I'd share the information in
> case somebody is interested .
>
> I am CCing Tristan because he's the last person who made fixes to keep
> the macOS support somewhat working (thanks!).  If you could at least
> tell if you get the same error, it would be helpful.

I'll try to investigate as well, but for obvious reasons I don't have a
mac.  I'll keep you posted.

Thanks,
diff mbox

Patch

diff --git a/gdb/Makefile.in b/gdb/Makefile.in
index 6bb44d7..642b711 100644
--- a/gdb/Makefile.in
+++ b/gdb/Makefile.in
@@ -1524,6 +1524,7 @@  HFILES_NO_SRCDIR = \
 	common/gdb_termios.h \
 	common/gdb_vecs.h \
 	common/gdb_wait.h \
+	common/common-inferior.h \
 	common/host-defs.h \
 	common/print-utils.h \
 	common/ptid.h \
@@ -1564,6 +1565,7 @@  HFILES_NO_SRCDIR = \
 	nat/amd64-linux-siginfo.h \
 	nat/gdb_ptrace.h \
 	nat/gdb_thread_db.h \
+	nat/fork-inferior.h \
 	nat/linux-btrace.h \
 	nat/linux-namespaces.h \
 	nat/linux-nat.h \
diff --git a/gdb/common/common-inferior.h b/gdb/common/common-inferior.h
new file mode 100644
index 0000000..87c1300
--- /dev/null
+++ b/gdb/common/common-inferior.h
@@ -0,0 +1,33 @@ 
+/* Functions to deal with the inferior being executed on GDB or
+   GDBserver.
+
+   Copyright (C) 1986-2017 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/>.  */
+
+#ifndef COMMON_INFERIOR_H
+#define COMMON_INFERIOR_H
+
+/* Return the exec wrapper to be used when starting the inferior, or NULL
+   otherwise.  */
+extern const char *get_exec_wrapper ();
+
+/* Return the name of the executable file as a string.
+   ERR nonzero means get error if there is none specified;
+   otherwise return 0 in that case.  */
+extern char *get_exec_file (int err);
+
+#endif /* ! COMMON_INFERIOR_H */
diff --git a/gdb/common/common-utils.c b/gdb/common/common-utils.c
index e94fdc4..fbec0da 100644
--- a/gdb/common/common-utils.c
+++ b/gdb/common/common-utils.c
@@ -18,6 +18,7 @@ 
    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
 
 #include "common-defs.h"
+#include "common-utils.h"
 #include "host-defs.h"
 #include <ctype.h>
 
@@ -328,3 +329,50 @@  free_vector_argv (std::vector<char *> &v)
 
   v.clear ();
 }
+
+/* See common/common-utils.h.  */
+
+std::string
+stringify_argv (const std::vector<char *> &args)
+{
+  std::string ret;
+
+  if (!args.empty ())
+    {
+      for (auto s : args)
+	if (s != NULL)
+	  {
+	    ret += s;
+	    ret += ' ';
+	  }
+
+      /* Erase the last whitespace.  */
+      ret.erase (ret.end () - 1);
+    }
+
+  return ret;
+}
+
+/* See common/common-inferior.h.  */
+
+void
+trace_start_error (const char *fmt, ...)
+{
+  va_list ap;
+
+  va_start (ap, fmt);
+  warning ("Could not trace the inferior process.\nError: ");
+  vwarning (fmt, ap);
+  va_end (ap);
+
+  gdb_flush_out_err ();
+  _exit (0177);
+}
+
+/* See common/common-inferior.h.  */
+
+void
+trace_start_error_with_name (const char *string)
+{
+  trace_start_error ("%s: %s", string, safe_strerror (errno));
+}
diff --git a/gdb/common/common-utils.h b/gdb/common/common-utils.h
index c331f0d..38505e0 100644
--- a/gdb/common/common-utils.h
+++ b/gdb/common/common-utils.h
@@ -108,4 +108,24 @@  extern const char *skip_to_space_const (const char *inp);
    freeing all the elements.  */
 extern void free_vector_argv (std::vector<char *> &v);
 
+/* Given a vector of arguments ARGV, return a string equivalent to
+   joining all the arguments with a whitespace separating them.  */
+extern std::string stringify_argv (const std::vector<char *> &argv);
+
+/* Flush both stdout and stderr.  This function needs to be
+   implemented differently on GDB and GDBserver.  */
+extern void gdb_flush_out_err ();
+
+/* Report an error that happened when starting to trace the inferior
+   (i.e., when the "traceme_fun" callback is called on fork_inferior)
+   and bail out.  This function does not return.  */
+extern void trace_start_error (const char *fmt, ...)
+  ATTRIBUTE_NORETURN;
+
+/* Like "trace_start_error", but the error message is constructed by
+   combining STRING with the system error message for errno.  This
+   function does not return.  */
+extern void trace_start_error_with_name (const char *string)
+  ATTRIBUTE_NORETURN;
+
 #endif
diff --git a/gdb/configure.nat b/gdb/configure.nat
index e6c96da..e6da599 100644
--- a/gdb/configure.nat
+++ b/gdb/configure.nat
@@ -54,7 +54,7 @@ 
 case ${gdb_host} in
     *linux*)
 	NAT_FILE='config/nm-linux.h'
-	NATDEPFILES='inf-ptrace.o fork-child.o proc-service.o \
+	NATDEPFILES='inf-ptrace.o fork-child.o fork-inferior.o proc-service.o \
 		linux-thread-db.o linux-nat.o linux-osdata.o linux-fork.o \
 		linux-procfs.o linux-ptrace.o linux-waitpid.o \
 		linux-personality.o linux-namespaces.o'
@@ -62,15 +62,15 @@  case ${gdb_host} in
 	LOADLIBES='-ldl $(RDYNAMIC)'
 	;;
     fbsd*)
-	NATDEPFILES='fork-child.o inf-ptrace.o fbsd-nat.o'
+	NATDEPFILES='fork-child.o fork-inferior.o inf-ptrace.o fbsd-nat.o'
 	HAVE_NATIVE_GCORE_HOST=1
 	LOADLIBES='-lkvm'
 	;;
     nbsd*)
-	NATDEPFILES='fork-child.o inf-ptrace.o'
+	NATDEPFILES='fork-child.o fork-inferior.o inf-ptrace.o'
 	;;
     obsd*)
-	NATDEPFILES='fork-child.o inf-ptrace.o'
+	NATDEPFILES='fork-child.o fork-inferior.o inf-ptrace.o'
 	;;
     cygwin*)
 	NATDEPFILES='x86-nat.o x86-dregs.o windows-nat.o'
diff --git a/gdb/corefile.c b/gdb/corefile.c
index 13a90b9..33eb4d1 100644
--- a/gdb/corefile.c
+++ b/gdb/corefile.c
@@ -170,9 +170,7 @@  validate_files (void)
     }
 }
 
-/* Return the name of the executable file as a string.
-   ERR nonzero means get error if there is none specified;
-   otherwise return 0 in that case.  */
+/* See common/common-inferior.h.  */
 
 char *
 get_exec_file (int err)
diff --git a/gdb/darwin-nat.c b/gdb/darwin-nat.c
index cba84ca..4330a60 100644
--- a/gdb/darwin-nat.c
+++ b/gdb/darwin-nat.c
@@ -1790,7 +1790,7 @@  darwin_ptrace_him (int pid)
 
   darwin_init_thread_list (inf);
 
-  startup_inferior (START_INFERIOR_TRAPS_EXPECTED);
+  gdb_startup_inferior (pid, START_INFERIOR_TRAPS_EXPECTED);
 }
 
 static void
@@ -1833,13 +1833,23 @@  darwin_create_inferior (struct target_ops *ops,
 			const std::string &allargs,
 			char **env, int from_tty)
 {
+  pid_t pid;
+  ptid_t ptid;
+
   /* Do the hard work.  */
-  fork_inferior (exec_file, allargs, env, darwin_ptrace_me, darwin_ptrace_him,
-		 darwin_pre_ptrace, NULL, darwin_execvp);
+  pid = fork_inferior (exec_file, allargs, env, darwin_ptrace_me,
+		       darwin_ptrace_him, darwin_pre_ptrace, NULL,
+		       darwin_execvp);
 
+  ptid = pid_to_ptid (pid);
   /* Return now in case of error.  */
   if (ptid_equal (inferior_ptid, null_ptid))
     return;
+
+  /* We have something that executes now.  We'll be running through
+     the shell at this point (if startup-with-shell is true), but the
+     pid shouldn't change.  */
+  add_thread_silent (ptid);
 }
 
 
diff --git a/gdb/fork-child.c b/gdb/fork-child.c
index c1b6f53..39e49b5 100644
--- a/gdb/fork-child.c
+++ b/gdb/fork-child.c
@@ -21,471 +21,55 @@ 
 
 #include "defs.h"
 #include "inferior.h"
+#include "gdbcmd.h"
 #include "terminal.h"
-#include "target.h"
-#include "gdb_wait.h"
-#include "gdb_vfork.h"
-#include "gdbcore.h"
 #include "gdbthread.h"
-#include "command.h" /* for dont_repeat () */
-#include "gdbcmd.h"
-#include "solib.h"
-#include "filestuff.h"
 #include "top.h"
-#include "signals-state-save-restore.h"
 #include "job-control.h"
-#include <signal.h>
-#include <vector>
-
-/* This just gets used as a default if we can't find SHELL.  */
-#define SHELL_FILE "/bin/sh"
-
-extern char **environ;
+#include "filestuff.h"
+#include "nat/fork-inferior.h"
+#include "common/common-inferior.h"
 
-static char *exec_wrapper;
+/* The exec-wrapper, if any, that will be used when starting the
+   inferior.  */
 
-/* Build the argument vector for execv(3).  */
+static char *exec_wrapper = NULL;
 
-class execv_argv
-{
-public:
-  /* EXEC_FILE is the file to run.  ALLARGS is a string containing the
-     arguments to the program.  If starting with a shell, SHELL_FILE
-     is the shell to run.  Otherwise, SHELL_FILE is NULL.  */
-  execv_argv (const char *exec_file, const std::string &allargs,
-	      const char *shell_file);
-
-  /* Return a pointer to the built argv, in the type expected by
-     execv.  The result is (only) valid for as long as this execv_argv
-     object is live.  We return a "char **" because that's the type
-     that the execv functions expect.  Note that it is guaranteed that
-     the execv functions do not modify the argv[] array nor the
-     strings to which the array point.  */
-  char **argv ()
-  {
-    return const_cast<char **> (&m_argv[0]);
-  }
-
-private:
-  /* Disable copying.  */
-  execv_argv (const execv_argv &) = delete;
-  void operator= (const execv_argv &) = delete;
-
-  /* Helper methods for constructing the argument vector.  */
-
-  /* Used when building an argv for a straight execv call, without
-     going via the shell.  */
-  void init_for_no_shell (const char *exec_file,
-			  const std::string &allargs);
-
-  /* Used when building an argv for execing a shell that execs the
-     child program.  */
-  void init_for_shell (const char *exec_file,
-		       const std::string &allargs,
-		       const char *shell_file);
-
-  /* The argument vector built.  Holds non-owning pointers.  Elements
-     either point to the strings passed to the execv_argv ctor, or
-     inside M_STORAGE.  */
-  std::vector<const char *> m_argv;
-
-  /* Storage.  In the no-shell case, this contains a copy of the
-     arguments passed to the ctor, split by '\0'.  In the shell case,
-     this contains the quoted shell command.  I.e., SHELL_COMMAND in
-     {"$SHELL" "-c", SHELL_COMMAND, NULL}.  */
-  std::string m_storage;
-};
-
-/* Create argument vector for straight call to execvp.  Breaks up
-   ALLARGS into an argument vector suitable for passing to execvp and
-   stores it in M_ARGV.  E.g., on "run a b c d" this routine would get
-   as input the string "a b c d", and as output it would fill in
-   M_ARGV with the four arguments "a", "b", "c", "d".  Each argument
-   in M_ARGV points to a substring of a copy of ALLARGS stored in
-   M_STORAGE.  */
+/* See common/common-inferior.h.  */
 
-void
-execv_argv::init_for_no_shell (const char *exec_file,
-			       const std::string &allargs)
+const char *
+get_exec_wrapper ()
 {
-
-  /* Save/work with a copy stored in our storage.  The pointers pushed
-     to M_ARGV point directly into M_STORAGE, which is modified in
-     place with the necessary NULL terminators.  This avoids N heap
-     allocations and string dups when 1 is sufficient.  */
-  std::string &args_copy = m_storage = allargs;
-
-  m_argv.push_back (exec_file);
-
-  for (size_t cur_pos = 0; cur_pos < args_copy.size ();)
-    {
-      /* Skip whitespace-like chars.  */
-      std::size_t pos = args_copy.find_first_not_of (" \t\n", cur_pos);
-
-      if (pos != std::string::npos)
-	cur_pos = pos;
-
-      /* Find the position of the next separator.  */
-      std::size_t next_sep = args_copy.find_first_of (" \t\n", cur_pos);
-
-      if (next_sep == std::string::npos)
-	{
-	  /* No separator found, which means this is the last
-	     argument.  */
-	  next_sep = args_copy.size ();
-	}
-      else
-	{
-	  /* Replace the separator with a terminator.  */
-	  args_copy[next_sep++] = '\0';
-	}
-
-      m_argv.push_back (&args_copy[cur_pos]);
-
-      cur_pos = next_sep;
-    }
-
-  /* NULL-terminate the vector.  */
-  m_argv.push_back (NULL);
+  return exec_wrapper;
 }
 
-/* When executing a command under the given shell, return true if the
-   '!' character should be escaped when embedded in a quoted
-   command-line argument.  */
-
-static bool
-escape_bang_in_quoted_argument (const char *shell_file)
-{
-  size_t shell_file_len = strlen (shell_file);
-
-  /* Bang should be escaped only in C Shells.  For now, simply check
-     that the shell name ends with 'csh', which covers at least csh
-     and tcsh.  This should be good enough for now.  */
-
-  if (shell_file_len < 3)
-    return false;
+/* The ui structure that will be saved on 'prefork_hook' and
+   restored on 'postfork_hook'.  */
+static struct ui *saved_ui = NULL;
 
-  if (shell_file[shell_file_len - 3] == 'c'
-      && shell_file[shell_file_len - 2] == 's'
-      && shell_file[shell_file_len - 1] == 'h')
-    return true;
-
-  return false;
-}
-
-/* See declaration.  */
-
-execv_argv::execv_argv (const char *exec_file,
-			const std::string &allargs,
-			const char *shell_file)
-{
-  if (shell_file == NULL)
-    init_for_no_shell (exec_file, allargs);
-  else
-    init_for_shell (exec_file, allargs, shell_file);
-}
-
-/* See declaration.  */
+/* See nat/fork-inferior.h.  */
 
 void
-execv_argv::init_for_shell (const char *exec_file,
-			    const std::string &allargs,
-			    const char *shell_file)
+prefork_hook (const char *args)
 {
-  /* We're going to call a shell.  */
-  bool escape_bang = escape_bang_in_quoted_argument (shell_file);
-
-  /* We need to build a new shell command string, and make argv point
-     to it.  So build it in the storage.  */
-  std::string &shell_command = m_storage;
-
-  shell_command = "exec ";
-
-  /* Add any exec wrapper.  That may be a program name with arguments,
-     so the user must handle quoting.  */
-  if (exec_wrapper)
-    {
-      shell_command += exec_wrapper;
-      shell_command += ' ';
-    }
-
-  /* Now add exec_file, quoting as necessary.  */
-
-  /* Quoting in this style is said to work with all shells.  But csh
-     on IRIX 4.0.1 can't deal with it.  So we only quote it if we need
-     to.  */
-  bool need_to_quote;
-  const char *p = exec_file;
-  while (1)
-    {
-      switch (*p)
-	{
-	case '\'':
-	case '!':
-	case '"':
-	case '(':
-	case ')':
-	case '$':
-	case '&':
-	case ';':
-	case '<':
-	case '>':
-	case ' ':
-	case '\n':
-	case '\t':
-	  need_to_quote = true;
-	  goto end_scan;
-
-	case '\0':
-	  need_to_quote = false;
-	  goto end_scan;
-
-	default:
-	  break;
-	}
-      ++p;
-    }
- end_scan:
-  if (need_to_quote)
-    {
-      shell_command += '\'';
-      for (p = exec_file; *p != '\0'; ++p)
-	{
-	  if (*p == '\'')
-	    shell_command += "'\\''";
-	  else if (*p == '!' && escape_bang)
-	    shell_command += "\\!";
-	  else
-	    shell_command += *p;
-	}
-      shell_command += '\'';
-    }
-  else
-    shell_command += exec_file;
-
-  shell_command += ' ' + allargs;
-
-  /* If we decided above to start up with a shell, we exec the shell.
-     "-c" says to interpret the next arg as a shell command to
-     execute, and this command is "exec <target-program> <args>".  */
-  m_argv.reserve (4);
-  m_argv.push_back (shell_file);
-  m_argv.push_back ("-c");
-  m_argv.push_back (shell_command.c_str ());
-  m_argv.push_back (NULL);
-}
-
-/* See inferior.h.  */
-
-void
-trace_start_error (const char *fmt, ...)
-{
-  va_list ap;
-
-  va_start (ap, fmt);
-  fprintf_unfiltered (gdb_stderr, "Could not trace the inferior "
-		                  "process.\nError: ");
-  vfprintf_unfiltered (gdb_stderr, fmt, ap);
-  va_end (ap);
-
-  gdb_flush (gdb_stderr);
-  _exit (0177);
-}
-
-/* See inferior.h.  */
-
-void
-trace_start_error_with_name (const char *string)
-{
-  trace_start_error ("%s: %s", string, safe_strerror (errno));
-}
-
-/* Start an inferior Unix child process and sets inferior_ptid to its
-   pid.  EXEC_FILE is the file to run.  ALLARGS is a string containing
-   the arguments to the program.  ENV is the environment vector to
-   pass.  SHELL_FILE is the shell file, or NULL if we should pick
-   one.  EXEC_FUN is the exec(2) function to use, or NULL for the default
-   one.  */
-
-/* This function is NOT reentrant.  Some of the variables have been
-   made static to ensure that they survive the vfork call.  */
-
-int
-fork_inferior (const char *exec_file_arg, const std::string &allargs,
-	       char **env, void (*traceme_fun) (void),
-	       void (*init_trace_fun) (int), void (*pre_trace_fun) (void),
-	       char *shell_file_arg,
-               void (*exec_fun)(const char *file, char * const *argv,
-                                char * const *env))
-{
-  int pid;
-  static char default_shell_file[] = SHELL_FILE;
-  /* Set debug_fork then attach to the child while it sleeps, to debug.  */
-  static int debug_fork = 0;
-  /* 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;
-  static char *shell_file;
-  static const char *exec_file;
-  char **save_our_env;
   const char *inferior_io_terminal = get_inferior_io_terminal ();
-  struct inferior *inf;
-  int i;
-  int save_errno;
-  struct ui *save_ui;
-
-  /* If no exec file handed to us, get it from the exec-file command
-     -- with a good, common error message if none is specified.  */
-  if (exec_file_arg == NULL)
-    exec_file = get_exec_file (1);
-  else
-    exec_file = exec_file_arg;
-
-  /* 'startup_with_shell' is declared in inferior.h and bound to the
-     "set startup-with-shell" option.  If 0, we'll just do a
-     fork/exec, no shell, so don't bother figuring out what shell.  */
-  if (startup_with_shell)
-    {
-      shell_file = shell_file_arg;
-      /* Figure out what shell to start up the user program under.  */
-      if (shell_file == NULL)
-	shell_file = getenv ("SHELL");
-      if (shell_file == NULL)
-	shell_file = default_shell_file;
-    }
-  else
-    shell_file = NULL;
-
-  /* Build the argument vector.  */
-  execv_argv child_argv (exec_file, allargs, shell_file);
 
-  /* Retain a copy of our environment variables, since the child will
-     replace the value of environ and if we're vforked, we have to
-     restore it.  */
-  save_our_env = environ;
-
-  /* Likewise the current UI.  */
-  save_ui = current_ui;
+  gdb_assert (saved_ui == NULL);
+  /* Retain a copy of our UI, since the child will replace this value
+     and if we're vforked, we have to restore it.  */
+  saved_ui = current_ui;
 
   /* Tell the terminal handling subsystem what tty we plan to run on;
      it will just record the information for later.  */
   new_tty_prefork (inferior_io_terminal);
+}
 
-  /* It is generally good practice to flush any possible pending stdio
-     output prior to doing a fork, to avoid the possibility of both
-     the parent and child flushing the same data after the fork.  */
-  gdb_flush (main_ui->m_gdb_stdout);
-  gdb_flush (main_ui->m_gdb_stderr);
-
-  /* If there's any initialization of the target layers that must
-     happen to prepare to handle the child we're about fork, do it
-     now...  */
-  if (pre_trace_fun != NULL)
-    (*pre_trace_fun) ();
-
-  /* Create the child process.  Since the child process is going to
-     exec(3) shortly afterwards, try to reduce the overhead by
-     calling vfork(2).  However, if PRE_TRACE_FUN is non-null, it's
-     likely that this optimization won't work since there's too much
-     work to do between the vfork(2) and the exec(3).  This is known
-     to be the case on ttrace(2)-based HP-UX, where some handshaking
-     between parent and child needs to happen between fork(2) and
-     exec(2).  However, since the parent is suspended in the vforked
-     state, this doesn't work.  Also note that the vfork(2) call might
-     actually be a call to fork(2) due to the fact that autoconf will
-     ``#define vfork fork'' on certain platforms.  */
-  if (pre_trace_fun || debug_fork)
-    pid = fork ();
-  else
-    pid = vfork ();
-
-  if (pid < 0)
-    perror_with_name (("vfork"));
-
-  if (pid == 0)
-    {
-      /* Switch to the main UI, so that gdb_std{in/out/err} in the
-	 child are mapped to std{in/out/err}.  This makes it possible
-	 to use fprintf_unfiltered/warning/error/etc. in the child
-	 from here on.  */
-      current_ui = main_ui;
-
-      /* Close all file descriptors except those that gdb inherited
-	 (usually 0/1/2), so they don't leak to the inferior.  Note
-	 that this closes the file descriptors of all secondary
-	 UIs.  */
-      close_most_fds ();
-
-      if (debug_fork)
-	sleep (debug_fork);
-
-      /* Create a new session for the inferior process, if necessary.
-         It will also place the inferior in a separate process group.  */
-      if (create_tty_session () <= 0)
-	{
-	  /* No session was created, but we still want to run the inferior
-	     in a separate process group.  */
-	  debug_setpgrp = gdb_setpgid ();
-	  if (debug_setpgrp == -1)
-	    perror (_("setpgrp failed in child"));
-	}
-
-      /* Ask the tty subsystem to switch to the one we specified
-         earlier (or to share the current terminal, if none was
-         specified).  */
-      new_tty ();
-
-      /* Changing the signal handlers for the inferior after
-         a vfork can also change them for the superior, so we don't mess
-         with signals here.  See comments in
-         initialize_signals for how we get the right signal handlers
-         for the inferior.  */
-
-      /* "Trace me, Dr. Memory!"  */
-      (*traceme_fun) ();
-
-      /* The call above set this process (the "child") as debuggable
-        by the original gdb process (the "parent").  Since processes
-        (unlike people) can have only one parent, if you are debugging
-        gdb itself (and your debugger is thus _already_ the
-        controller/parent for this child), code from here on out is
-        undebuggable.  Indeed, you probably got an error message
-        saying "not parent".  Sorry; you'll have to use print
-        statements!  */
-
-      restore_original_signals_state ();
-
-      /* There is no execlpe call, so we have to set the environment
-         for our child in the global variable.  If we've vforked, this
-         clobbers the parent, but environ is restored a few lines down
-         in the parent.  By the way, yes we do need to look down the
-         path to find $SHELL.  Rich Pixley says so, and I agree.  */
-      environ = env;
-
-      char **argv = child_argv.argv ();
-
-      if (exec_fun != NULL)
-        (*exec_fun) (argv[0], &argv[0], env);
-      else
-        execvp (argv[0], &argv[0]);
-
-      /* If we get here, it's an error.  */
-      save_errno = errno;
-      fprintf_unfiltered (gdb_stderr, "Cannot exec %s", argv[0]);
-      for (i = 1; argv[i] != NULL; i++)
-	fprintf_unfiltered (gdb_stderr, " %s", argv[i]);
-      fprintf_unfiltered (gdb_stderr, ".\n");
-      fprintf_unfiltered (gdb_stderr, "Error: %s\n",
-			  safe_strerror (save_errno));
-      gdb_flush (gdb_stderr);
-      _exit (0177);
-    }
-
-  /* Restore our environment in case a vforked child clob'd it.  */
-  environ = save_our_env;
+/* See nat/fork-inferior.h.  */
 
-  /* Likewise the current UI.  */
-  current_ui = save_ui;
+void
+postfork_hook (pid_t pid)
+{
+  struct inferior *inf;
 
   if (!have_inferiors ())
     init_thread_list ();
@@ -494,147 +78,58 @@  fork_inferior (const char *exec_file_arg, const std::string &allargs,
 
   inferior_appeared (inf, pid);
 
-  /* Needed for wait_for_inferior stuff below.  */
+  /* Needed for wait_for_inferior stuff.  */
   inferior_ptid = pid_to_ptid (pid);
 
-  new_tty_postfork ();
+  gdb_assert (saved_ui != NULL);
+  current_ui = saved_ui;
+  saved_ui = NULL;
 
-  /* We have something that executes now.  We'll be running through
-     the shell at this point, but the pid shouldn't change.  Targets
-     supporting MT should fill this task's ptid with more data as soon
-     as they can.  */
-  add_thread_silent (inferior_ptid);
-
-  /* Now that we have a child process, make it our target, and
-     initialize anything target-vector-specific that needs
-     initializing.  */
-  if (init_trace_fun)
-    (*init_trace_fun) (pid);
-
-  /* We are now in the child process of interest, having exec'd the
-     correct program, and are poised at the first instruction of the
-     new program.  */
-  return pid;
+  new_tty_postfork ();
 }
 
-/* Accept NTRAPS traps from the inferior.  */
+/* See nat/fork-inferior.h.  */
 
 void
-startup_inferior (int ntraps)
+postfork_child_hook ()
 {
-  int pending_execs = ntraps;
-  int terminal_initted = 0;
-  ptid_t resume_ptid;
+  /* 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;
+
+  /* Make sure we switch to main_ui here in order to be able to
+     use the fprintf_unfiltered/warning/error functions.  */
+  current_ui = main_ui;
 
-  if (startup_with_shell)
+  /* Create a new session for the inferior process, if necessary.
+     It will also place the inferior in a separate process group.  */
+  if (create_tty_session () <= 0)
     {
-      /* One trap extra for exec'ing the shell.  */
-      pending_execs++;
+      /* No session was created, but we still want to run the inferior
+	 in a separate process group.  */
+      debug_setpgrp = gdb_setpgid ();
+      if (debug_setpgrp == -1)
+	perror (_("setpgrp failed in child"));
     }
 
-  if (target_supports_multi_process ())
-    resume_ptid = pid_to_ptid (ptid_get_pid (inferior_ptid));
-  else
-    resume_ptid = minus_one_ptid;
-
-  /* The process was started by the fork that created it, but it will
-     have stopped one instruction after execing the shell.  Here we
-     must get it up to actual execution of the real program.  */
+  /* Ask the tty subsystem to switch to the one we specified
+     earlier (or to share the current terminal, if none was
+     specified).  */
+  new_tty ();
+}
 
-  if (exec_wrapper)
-    pending_execs++;
+/* See inferior.h.  */
 
-  while (1)
-    {
-      enum gdb_signal resume_signal = GDB_SIGNAL_0;
-      ptid_t event_ptid;
-
-      struct target_waitstatus ws;
-      memset (&ws, 0, sizeof (ws));
-      event_ptid = target_wait (resume_ptid, &ws, 0);
-
-      if (ws.kind == TARGET_WAITKIND_IGNORE)
-	/* The inferior didn't really stop, keep waiting.  */
-	continue;
-
-      switch (ws.kind)
-	{
-	  case TARGET_WAITKIND_SPURIOUS:
-	  case TARGET_WAITKIND_LOADED:
-	  case TARGET_WAITKIND_FORKED:
-	  case TARGET_WAITKIND_VFORKED:
-	  case TARGET_WAITKIND_SYSCALL_ENTRY:
-	  case TARGET_WAITKIND_SYSCALL_RETURN:
-	    /* Ignore gracefully during startup of the inferior.  */
-	    switch_to_thread (event_ptid);
-	    break;
-
-	  case TARGET_WAITKIND_SIGNALLED:
-	    target_terminal_ours ();
-	    target_mourn_inferior (event_ptid);
-	    error (_("During startup program terminated with signal %s, %s."),
-		   gdb_signal_to_name (ws.value.sig),
-		   gdb_signal_to_string (ws.value.sig));
-	    return;
-
-	  case TARGET_WAITKIND_EXITED:
-	    target_terminal_ours ();
-	    target_mourn_inferior (event_ptid);
-	    if (ws.value.integer)
-	      error (_("During startup program exited with code %d."),
-		     ws.value.integer);
-	    else
-	      error (_("During startup program exited normally."));
-	    return;
-
-	  case TARGET_WAITKIND_EXECD:
-	    /* Handle EXEC signals as if they were SIGTRAP signals.  */
-	    xfree (ws.value.execd_pathname);
-	    resume_signal = GDB_SIGNAL_TRAP;
-	    switch_to_thread (event_ptid);
-	    break;
-
-	  case TARGET_WAITKIND_STOPPED:
-	    resume_signal = ws.value.sig;
-	    switch_to_thread (event_ptid);
-	    break;
-	}
-
-      if (resume_signal != GDB_SIGNAL_TRAP)
-	{
-	  /* Let shell child handle its own signals in its own way.  */
-	  target_continue (resume_ptid, resume_signal);
-	}
-      else
-	{
-	  /* We handle SIGTRAP, however; it means child did an exec.  */
-	  if (!terminal_initted)
-	    {
-	      /* Now that the child has exec'd we know it has already
-	         set its process group.  On POSIX systems, tcsetpgrp
-	         will fail with EPERM if we try it before the child's
-	         setpgid.  */
-
-	      /* Set up the "saved terminal modes" of the inferior
-	         based on what modes we are starting it with.  */
-	      target_terminal_init ();
-
-	      /* Install inferior's terminal modes.  */
-	      target_terminal_inferior ();
-
-	      terminal_initted = 1;
-	    }
-
-	  if (--pending_execs == 0)
-	    break;
-
-	  /* Just make it go on.  */
-	  target_continue_no_signal (resume_ptid);
-	}
-    }
+ptid_t
+gdb_startup_inferior (pid_t pid, int num_traps)
+{
+  ptid_t ptid = startup_inferior (pid, num_traps, NULL, NULL);
 
   /* Mark all threads non-executing.  */
-  set_executing (resume_ptid, 0);
+  set_executing (ptid, 0);
+
+  return ptid;
 }
 
 /* Implement the "unset exec-wrapper" command.  */
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 b/gdb/gdbserver/configure
index b314c41..96befef 100755
--- a/gdb/gdbserver/configure
+++ b/gdb/gdbserver/configure
@@ -8422,7 +8422,9 @@  fi
 
 if $want_ipa ; then
    if $have_ipa ; then
-     IPA_DEPFILES="$ipa_obj"
+     # Needed because safe_strerror's definition is host-dependent
+     strerror_obj="`echo $srv_host_obs | sed 's/\(.*-strerror\)\.o/\1-ipa.o/'`"
+     IPA_DEPFILES="$ipa_obj $strerror_obj"
      extra_libraries="$extra_libraries libinproctrace.so"
    else
      as_fn_error "inprocess agent not supported for this target" "$LINENO" 5
diff --git a/gdb/gdbserver/configure.ac b/gdb/gdbserver/configure.ac
index 4ea7913..8aa85db 100644
--- a/gdb/gdbserver/configure.ac
+++ b/gdb/gdbserver/configure.ac
@@ -462,7 +462,9 @@  esac],
 
 if $want_ipa ; then
    if $have_ipa ; then
-     IPA_DEPFILES="$ipa_obj"
+     # Needed because safe_strerror's definition is host-dependent
+     strerror_obj="`echo $srv_host_obs | sed 's/\(.*-strerror\)\.o/\1-ipa.o/'`"
+     IPA_DEPFILES="$ipa_obj $strerror_obj"
      extra_libraries="$extra_libraries libinproctrace.so"
    else
      AC_MSG_ERROR([inprocess agent not supported for this target])
diff --git a/gdb/gdbserver/configure.srv b/gdb/gdbserver/configure.srv
index d00d9e2..056ac27 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-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-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 "${target}" in
 			srv_linux_thread_db=yes
 			;;
   spu*-*-*)		srv_regobj=reg-spu.o
-			srv_tgtobj="spu-low.o"
+			srv_tgtobj="spu-low.o fork-inferior.o"
 			;;
   tic6x-*-uclinux)	srv_regobj="tic6x-c64xp-linux.o"
 			srv_regobj="${srv_regobj} tic6x-c64x-linux.o"
diff --git a/gdb/gdbserver/linux-low.c b/gdb/gdbserver/linux-low.c
index ea3c81b..ab6670b 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, startup_inferior);
+
   return pid;
 }
 
diff --git a/gdb/gdbserver/lynx-low.c b/gdb/gdbserver/lynx-low.c
index d300aae..382d71c 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, startup_inferior);
 
   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..5a76927 100644
--- a/gdb/gdbserver/server.c
+++ b/gdb/gdbserver/server.c
@@ -36,6 +36,20 @@ 
 #include "dll.h"
 #include "hostio.h"
 #include <vector>
+#include "common-inferior.h"
+#include "nat/fork-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 +93,9 @@  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];
@@ -238,25 +253,41 @@  target_running (void)
   return get_first_thread () != NULL;
 }
 
-static int
-start_inferior (char **argv)
+/* See common/common-inferior.h.  */
+
+const char *
+get_exec_wrapper ()
 {
-  std::vector<char *> new_argv;
+  return wrapper_argv.size () > 0 ? wrapper_argv.c_str () : NULL;
+}
+
+/* See common/common-inferior.h.  */
 
-  if (!wrapper_argv.empty ())
-    new_argv.insert (new_argv.begin (),
-		     wrapper_argv.begin (),
-		     wrapper_argv.end ());
+char *
+get_exec_file (int err)
+{
+  if (err && program_name == NULL)
+    error (_("No executable file specified."));
 
-  for (int i = 0; argv[i] != NULL; ++i)
-    new_argv.push_back (argv[i]);
+  return program_name;
+}
 
-  new_argv.push_back (NULL);
+/* See server.h.  */
+
+struct gdb_environ *
+get_environ ()
+{
+  return our_environ;
+}
+
+/* See nat/fork-inferior.h.  */
 
+void
+prefork_hook (const char *args)
+{
   if (debug_threads)
     {
-      for (int i = 0; i < new_argv.size (); ++i)
-	debug_printf ("new_argv[%d] = \"%s\"\n", i, new_argv[i]);
+      debug_printf ("args: %s\n", args);
       debug_flush ();
     }
 
@@ -265,67 +296,63 @@  start_inferior (char **argv)
   signal (SIGTTIN, SIG_DFL);
 #endif
 
-  signal_pid = create_inferior (new_argv[0], &new_argv[0]);
+  /* Clear this so the backend doesn't get confused, thinking
+     CONT_THREAD died, and it needs to resume all threads.  */
+  cont_thread = null_ptid;
+}
 
-  /* 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);
+/* See server.h.  */
+
+void
+post_fork_inferior (int pid, const char *program,
+		    ptid_t (*my_startup_inferior) (pid_t pid, int ntraps,
+						   struct target_waitstatus
+						   *mystatus,
+						   ptid_t *myptid))
+
+{
+  /* Number of traps to be expected by startup_inferior.  We always
+     expect at least one trap for the main executable.  */
+  int num_traps = START_INFERIOR_TRAPS_EXPECTED;
 
 #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);
+  tcsetpgrp (terminal_fd, 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);
-
-	      last_ptid = mywait (pid_to_ptid (signal_pid), &last_status, 0, 0);
-	      if (last_status.kind != TARGET_WAITKIND_STOPPED)
-		break;
+  my_startup_inferior (pid, num_traps, &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);
+}
 
-	      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;
-    }
+/* See nat/fork-inferior.h.  */
 
-  /* 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);
+void
+postfork_hook (pid_t pid)
+{
+}
 
-  /* 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 nat/fork-inferior.h.  */
 
-  return signal_pid;
+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"));
 }
 
 static int
@@ -2848,6 +2875,7 @@  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 +2894,94 @@  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 +3607,17 @@  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.size () > 0)
+	    {
+	      /* Erase the last whitespace.  */
+	      wrapper_argv.erase (wrapper_argv.end () - 1);
+	    }
+
 	  if (next_arg == tmp || *next_arg == NULL)
 	    {
 	      gdbserver_usage (stderr);
@@ -3666,8 +3753,13 @@  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 +3773,13 @@  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 +4394,10 @@  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..96566fe 100644
--- a/gdb/gdbserver/server.h
+++ b/gdb/gdbserver/server.h
@@ -148,4 +148,20 @@  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.  This is done here.  PID is the
+   pid of the new inferior, PROGRAM is its name, and
+   MY_STARTUP_INFERIOR is the function that should be called to start
+   the inferior and consume its first events.  In most cases, this
+   function should be "startup_inferior" itself.  */
+extern void post_fork_inferior (int pid, const char *program,
+				ptid_t (*my_startup_inferior)
+				(pid_t pid, int ntraps,
+				 struct target_waitstatus *mystatus,
+				 ptid_t *myptid));
+
+/* Get the 'struct gdb_environ *' being used in the current
+   session.  */
+extern struct gdb_environ *get_environ ();
+
 #endif /* SERVER_H */
diff --git a/gdb/gdbserver/spu-low.c b/gdb/gdbserver/spu-low.c
index 117b871..c71e8ba 100644
--- a/gdb/gdbserver/spu-low.c
+++ b/gdb/gdbserver/spu-low.c
@@ -27,6 +27,8 @@ 
 #include <sys/syscall.h>
 #include "filestuff.h"
 #include "hostio.h"
+#include "common-inferior.h"
+#include "nat/fork-inferior.h"
 
 /* Some older glibc versions do not define this.  */
 #ifndef __WNOTHREAD
@@ -261,36 +263,37 @@  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, startup_inferior);
 
   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/utils.c b/gdb/gdbserver/utils.c
index 307d15a..3f96a6c 100644
--- a/gdb/gdbserver/utils.c
+++ b/gdb/gdbserver/utils.c
@@ -137,3 +137,12 @@  pfildes (gdb_fildes_t fd)
   return plongest (fd);
 #endif
 }
+
+/* See common/common-utils.h.  */
+
+void
+gdb_flush_out_err ()
+{
+  fflush (stdout);
+  fflush (stderr);
+}
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
diff --git a/gdb/gnu-nat.c b/gdb/gnu-nat.c
index 6298103..d5e3841 100644
--- a/gdb/gnu-nat.c
+++ b/gdb/gnu-nat.c
@@ -2143,6 +2143,11 @@  gnu_create_inferior (struct target_ops *ops,
   pid = fork_inferior (exec_file, allargs, env, gnu_ptrace_me,
                        NULL, NULL, NULL, NULL);
 
+  /* We have something that executes now.  We'll be running through
+     the shell at this point (if startup-with-shell is true), but the
+     pid shouldn't change.  */
+  add_thread_silent (pid_to_ptid (pid));
+
   /* Attach to the now stopped child, which is actually a shell...  */
   inf_debug (inf, "attaching to child: %d", pid);
 
@@ -2162,7 +2167,8 @@  gnu_create_inferior (struct target_ops *ops,
   thread_change_ptid (inferior_ptid,
 		      ptid_build (inf->pid, inf_pick_first_thread (), 0));
 
-  startup_inferior (START_INFERIOR_TRAPS_EXPECTED);
+  gdb_startup_inferior (pid, START_INFERIOR_TRAPS_EXPECTED);
+
   inf->pending_execs = 0;
   /* Get rid of the old shell threads.  */
   prune_threads ();
diff --git a/gdb/inf-ptrace.c b/gdb/inf-ptrace.c
index b19aaf9..2a01dd2 100644
--- a/gdb/inf-ptrace.c
+++ b/gdb/inf-ptrace.c
@@ -31,6 +31,8 @@ 
 #include "inf-ptrace.h"
 #include "inf-child.h"
 #include "gdbthread.h"
+#include "nat/fork-inferior.h"
+#include "utils.h"
 
 
 
@@ -93,7 +95,8 @@  inf_ptrace_create_inferior (struct target_ops *ops,
 			    const char *exec_file, const std::string &allargs,
 			    char **env, int from_tty)
 {
-  int pid;
+  pid_t pid;
+  ptid_t ptid;  
 
   /* Do not change either targets above or the same target if already present.
      The reason is the target stack is shared across multiple inferiors.  */
@@ -110,13 +113,19 @@  inf_ptrace_create_inferior (struct target_ops *ops,
   pid = fork_inferior (exec_file, allargs, env, inf_ptrace_me, NULL,
 		       NULL, NULL, NULL);
 
+  ptid = pid_to_ptid (pid);
+  /* We have something that executes now.  We'll be running through
+     the shell at this point (if startup-with-shell is true), but the
+     pid shouldn't change.  */
+  add_thread_silent (ptid);
+
   discard_cleanups (back_to);
 
-  startup_inferior (START_INFERIOR_TRAPS_EXPECTED);
+  gdb_startup_inferior (pid, START_INFERIOR_TRAPS_EXPECTED);
 
   /* On some targets, there must be some explicit actions taken after
      the inferior has been started up.  */
-  target_post_startup_inferior (pid_to_ptid (pid));
+  target_post_startup_inferior (ptid);
 }
 
 #ifdef PT_GET_PROCESS_STATE
diff --git a/gdb/inferior.h b/gdb/inferior.h
index 7ee92ed..cdaeb11 100644
--- a/gdb/inferior.h
+++ b/gdb/inferior.h
@@ -45,6 +45,7 @@  struct inferior;
 
 #include "progspace.h"
 #include "registry.h"
+#include "common-inferior.h"
 
 #include "symfile-add-flags.h"
 #include "common/refcounted-object.h"
@@ -136,28 +137,10 @@  extern void child_terminal_init_with_pgrp (int pgrp);
 
 /* From fork-child.c */
 
-/* Report an error that happened when starting to trace the inferior
-   (i.e., when the "traceme_fun" callback is called on fork_inferior)
-   and bail out.  This function does not return.  */
-
-extern void trace_start_error (const char *fmt, ...)
-  ATTRIBUTE_NORETURN;
-
-/* Like "trace_start_error", but the error message is constructed by
-   combining STRING with the system error message for errno.  This
-   function does not return.  */
-
-extern void trace_start_error_with_name (const char *string)
-  ATTRIBUTE_NORETURN;
-
-extern int fork_inferior (const char *, const std::string &, char **,
-			  void (*)(void),
-			  void (*)(int), void (*)(void), char *,
-                          void (*)(const char *,
-                                   char * const *, char * const *));
-
-
-extern void startup_inferior (int);
+/* Helper function to call STARTUP_INFERIOR with PID and NUM_TRAPS.
+   This function already calls set_executing.  Return the ptid_t from
+   STARTUP_INFERIOR.  */
+extern ptid_t gdb_startup_inferior (pid_t pid, int num_traps);
 
 extern char *construct_inferior_arguments (int, char **);
 
@@ -282,12 +265,6 @@  enum stop_kind
 #define ON_STACK 1
 #define AT_ENTRY_POINT 4
 
-/* Number of traps that happen between exec'ing the shell to run an
-   inferior and when we finally get to the inferior code, not counting
-   the exec for the shell.  This is 1 on all supported
-   implementations.  */
-#define START_INFERIOR_TRAPS_EXPECTED	1
-
 struct private_inferior;
 
 /* Inferior process specific part of `struct infcall_control_state'.
diff --git a/gdb/nat/fork-inferior.c b/gdb/nat/fork-inferior.c
new file mode 100644
index 0000000..7fd93ef
--- /dev/null
+++ b/gdb/nat/fork-inferior.c
@@ -0,0 +1,569 @@ 
+/* Fork a Unix child process, and set up to debug it, for GDB and GDBserver.
+
+   Copyright (C) 1990-2017 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 "common-defs.h"
+#include "fork-inferior.h"
+#include "target/waitstatus.h"
+#include "filestuff.h"
+#include "target/target.h"
+#include "common-inferior.h"
+#include "common-gdbthread.h"
+#include "signals-state-save-restore.h"
+#include <vector>
+
+extern char **environ;
+
+/* Default shell file to be used if 'startup-with-shell' is set but
+   $SHELL is not.  */
+#define SHELL_FILE "/bin/sh"
+
+/* Build the argument vector for execv(3).  */
+
+class execv_argv
+{
+public:
+  /* EXEC_FILE is the file to run.  ALLARGS is a string containing the
+     arguments to the program.  If starting with a shell, SHELL_FILE
+     is the shell to run.  Otherwise, SHELL_FILE is NULL.  */
+  execv_argv (const char *exec_file, const std::string &allargs,
+	      const char *shell_file);
+
+  /* Return a pointer to the built argv, in the type expected by
+     execv.  The result is (only) valid for as long as this execv_argv
+     object is live.  We return a "char **" because that's the type
+     that the execv functions expect.  Note that it is guaranteed that
+     the execv functions do not modify the argv[] array nor the
+     strings to which the array point.  */
+  char **argv ()
+  {
+    return const_cast<char **> (&m_argv[0]);
+  }
+
+private:
+  /* Disable copying.  */
+  execv_argv (const execv_argv &) = delete;
+  void operator= (const execv_argv &) = delete;
+
+  /* Helper methods for constructing the argument vector.  */
+
+  /* Used when building an argv for a straight execv call, without
+     going via the shell.  */
+  void init_for_no_shell (const char *exec_file,
+			  const std::string &allargs);
+
+  /* Used when building an argv for execing a shell that execs the
+     child program.  */
+  void init_for_shell (const char *exec_file,
+		       const std::string &allargs,
+		       const char *shell_file);
+
+  /* The argument vector built.  Holds non-owning pointers.  Elements
+     either point to the strings passed to the execv_argv ctor, or
+     inside M_STORAGE.  */
+  std::vector<const char *> m_argv;
+
+  /* Storage.  In the no-shell case, this contains a copy of the
+     arguments passed to the ctor, split by '\0'.  In the shell case,
+     this contains the quoted shell command.  I.e., SHELL_COMMAND in
+     {"$SHELL" "-c", SHELL_COMMAND, NULL}.  */
+  std::string m_storage;
+};
+
+/* Create argument vector for straight call to execvp.  Breaks up
+   ALLARGS into an argument vector suitable for passing to execvp and
+   stores it in M_ARGV.  E.g., on "run a b c d" this routine would get
+   as input the string "a b c d", and as output it would fill in
+   M_ARGV with the four arguments "a", "b", "c", "d".  Each argument
+   in M_ARGV points to a substring of a copy of ALLARGS stored in
+   M_STORAGE.  */
+
+void
+execv_argv::init_for_no_shell (const char *exec_file,
+			       const std::string &allargs)
+{
+
+  /* Save/work with a copy stored in our storage.  The pointers pushed
+     to M_ARGV point directly into M_STORAGE, which is modified in
+     place with the necessary NULL terminators.  This avoids N heap
+     allocations and string dups when 1 is sufficient.  */
+  std::string &args_copy = m_storage = allargs;
+
+  m_argv.push_back (exec_file);
+
+  for (size_t cur_pos = 0; cur_pos < args_copy.size ();)
+    {
+      /* Skip whitespace-like chars.  */
+      std::size_t pos = args_copy.find_first_not_of (" \t\n", cur_pos);
+
+      if (pos != std::string::npos)
+	cur_pos = pos;
+
+      /* Find the position of the next separator.  */
+      std::size_t next_sep = args_copy.find_first_of (" \t\n", cur_pos);
+
+      if (next_sep == std::string::npos)
+	{
+	  /* No separator found, which means this is the last
+	     argument.  */
+	  next_sep = args_copy.size ();
+	}
+      else
+	{
+	  /* Replace the separator with a terminator.  */
+	  args_copy[next_sep++] = '\0';
+	}
+
+      m_argv.push_back (&args_copy[cur_pos]);
+
+      cur_pos = next_sep;
+    }
+
+  /* NULL-terminate the vector.  */
+  m_argv.push_back (NULL);
+}
+
+/* When executing a command under the given shell, return true if the
+   '!' character should be escaped when embedded in a quoted
+   command-line argument.  */
+
+static bool
+escape_bang_in_quoted_argument (const char *shell_file)
+{
+  size_t shell_file_len = strlen (shell_file);
+
+  /* Bang should be escaped only in C Shells.  For now, simply check
+     that the shell name ends with 'csh', which covers at least csh
+     and tcsh.  This should be good enough for now.  */
+
+  if (shell_file_len < 3)
+    return false;
+
+  if (shell_file[shell_file_len - 3] == 'c'
+      && shell_file[shell_file_len - 2] == 's'
+      && shell_file[shell_file_len - 1] == 'h')
+    return true;
+
+  return false;
+}
+
+/* See declaration.  */
+
+execv_argv::execv_argv (const char *exec_file,
+			const std::string &allargs,
+			const char *shell_file)
+{
+  if (shell_file == NULL)
+    init_for_no_shell (exec_file, allargs);
+  else
+    init_for_shell (exec_file, allargs, shell_file);
+}
+
+/* See declaration.  */
+
+void
+execv_argv::init_for_shell (const char *exec_file,
+			    const std::string &allargs,
+			    const char *shell_file)
+{
+  const char *exec_wrapper = get_exec_wrapper ();
+
+  /* We're going to call a shell.  */
+  bool escape_bang = escape_bang_in_quoted_argument (shell_file);
+
+  /* We need to build a new shell command string, and make argv point
+     to it.  So build it in the storage.  */
+  std::string &shell_command = m_storage;
+
+  shell_command = "exec ";
+
+  /* Add any exec wrapper.  That may be a program name with arguments,
+     so the user must handle quoting.  */
+  if (exec_wrapper != NULL)
+    {
+      shell_command += exec_wrapper;
+      shell_command += ' ';
+    }
+
+  /* Now add exec_file, quoting as necessary.  */
+
+  /* Quoting in this style is said to work with all shells.  But csh
+     on IRIX 4.0.1 can't deal with it.  So we only quote it if we need
+     to.  */
+  bool need_to_quote;
+  const char *p = exec_file;
+  while (1)
+    {
+      switch (*p)
+	{
+	case '\'':
+	case '!':
+	case '"':
+	case '(':
+	case ')':
+	case '$':
+	case '&':
+	case ';':
+	case '<':
+	case '>':
+	case ' ':
+	case '\n':
+	case '\t':
+	  need_to_quote = true;
+	  goto end_scan;
+
+	case '\0':
+	  need_to_quote = false;
+	  goto end_scan;
+
+	default:
+	  break;
+	}
+      ++p;
+    }
+ end_scan:
+  if (need_to_quote)
+    {
+      shell_command += '\'';
+      for (p = exec_file; *p != '\0'; ++p)
+	{
+	  if (*p == '\'')
+	    shell_command += "'\\''";
+	  else if (*p == '!' && escape_bang)
+	    shell_command += "\\!";
+	  else
+	    shell_command += *p;
+	}
+      shell_command += '\'';
+    }
+  else
+    shell_command += exec_file;
+
+  shell_command += ' ' + allargs;
+
+  /* If we decided above to start up with a shell, we exec the shell.
+     "-c" says to interpret the next arg as a shell command to
+     execute, and this command is "exec <target-program> <args>".  */
+  m_argv.reserve (4);
+  m_argv.push_back (shell_file);
+  m_argv.push_back ("-c");
+  m_argv.push_back (shell_command.c_str ());
+  m_argv.push_back (NULL);
+}
+
+/* Return the shell that must be used to startup the inferior.  The
+   first attempt is the environment variable SHELL; if it is not set,
+   then we default to SHELL_FILE.  */
+
+static const char *
+get_startup_shell ()
+{
+  static const char *ret;
+
+  ret = getenv ("SHELL");
+  if (ret == NULL)
+    ret = SHELL_FILE;
+
+  return ret;
+}
+
+/* See nat/fork-inferior.h.  */
+
+pid_t
+fork_inferior (const char *exec_file_arg, const std::string &allargs,
+	       char **env, void (*traceme_fun) (),
+	       void (*init_trace_fun) (int), void (*pre_trace_fun) (),
+	       const char *shell_file_arg,
+               void (*exec_fun)(const char *file, char * const *argv,
+                                char * const *env))
+{
+  pid_t pid;
+  /* Set debug_fork then attach to the child while it sleeps, to debug.  */
+  int debug_fork = 0;
+  const char *shell_file;
+  const char *exec_file;
+  char **save_our_env;
+  int i;
+  int save_errno;
+
+  /* If no exec file handed to us, get it from the exec-file command
+     -- with a good, common error message if none is specified.  */
+  if (exec_file_arg == NULL)
+    exec_file = get_exec_file (1);
+  else
+    exec_file = exec_file_arg;
+
+  /* 'startup_with_shell' is declared in inferior.h and bound to the
+     "set startup-with-shell" option.  If 0, we'll just do a
+     fork/exec, no shell, so don't bother figuring out what shell.  */
+  if (startup_with_shell)
+    {
+      shell_file = shell_file_arg;
+
+      /* Figure out what shell to start up the user program under.  */
+      if (shell_file == NULL)
+	shell_file = get_startup_shell ();
+
+      gdb_assert (shell_file != NULL);
+    }
+  else
+    shell_file = NULL;
+
+  /* Build the argument vector.  */
+  execv_argv child_argv (exec_file, allargs, shell_file);
+
+  /* Retain a copy of our environment variables, since the child will
+     replace the value of environ and if we're vforked, we have to
+     restore it.  */
+  save_our_env = environ;
+
+  /* Perform any necessary actions regarding to TTY before the
+     fork/vfork call.  */
+  prefork_hook (allargs.c_str ());
+
+  /* It is generally good practice to flush any possible pending stdio
+     output prior to doing a fork, to avoid the possibility of both
+     the parent and child flushing the same data after the fork.  */
+  gdb_flush_out_err ();
+
+  /* If there's any initialization of the target layers that must
+     happen to prepare to handle the child we're about fork, do it
+     now...  */
+  if (pre_trace_fun != NULL)
+    (*pre_trace_fun) ();
+
+  /* Create the child process.  Since the child process is going to
+     exec(3) shortly afterwards, try to reduce the overhead by
+     calling vfork(2).  However, if PRE_TRACE_FUN is non-null, it's
+     likely that this optimization won't work since there's too much
+     work to do between the vfork(2) and the exec(3).  This is known
+     to be the case on ttrace(2)-based HP-UX, where some handshaking
+     between parent and child needs to happen between fork(2) and
+     exec(2).  However, since the parent is suspended in the vforked
+     state, this doesn't work.  Also note that the vfork(2) call might
+     actually be a call to fork(2) due to the fact that autoconf will
+     ``#define vfork fork'' on certain platforms.  */
+  if (pre_trace_fun || debug_fork)
+    pid = fork ();
+  else
+    pid = vfork ();
+
+  if (pid < 0)
+    perror_with_name (("vfork"));
+
+  if (pid == 0)
+    {
+      /* Close all file descriptors except those that gdb inherited
+	 (usually 0/1/2), so they don't leak to the inferior.  Note
+	 that this closes the file descriptors of all secondary
+	 UIs.  */
+      close_most_fds ();
+
+      if (debug_fork)
+	sleep (debug_fork);
+
+      /* Execute any necessary post-fork actions before we exec.  */
+      postfork_child_hook ();
+
+      /* Changing the signal handlers for the inferior after
+         a vfork can also change them for the superior, so we don't mess
+         with signals here.  See comments in
+         initialize_signals for how we get the right signal handlers
+         for the inferior.  */
+
+      /* "Trace me, Dr. Memory!"  */
+      (*traceme_fun) ();
+
+      /* The call above set this process (the "child") as debuggable
+        by the original gdb process (the "parent").  Since processes
+        (unlike people) can have only one parent, if you are debugging
+        gdb itself (and your debugger is thus _already_ the
+        controller/parent for this child), code from here on out is
+        undebuggable.  Indeed, you probably got an error message
+        saying "not parent".  Sorry; you'll have to use print
+        statements!  */
+
+      restore_original_signals_state ();
+
+      /* There is no execlpe call, so we have to set the environment
+         for our child in the global variable.  If we've vforked, this
+         clobbers the parent, but environ is restored a few lines down
+         in the parent.  By the way, yes we do need to look down the
+         path to find $SHELL.  Rich Pixley says so, and I agree.  */
+      environ = env;
+
+      char **argv = child_argv.argv ();
+
+      if (exec_fun != NULL)
+        (*exec_fun) (argv[0], &argv[0], env);
+      else
+        execvp (argv[0], &argv[0]);
+
+      /* If we get here, it's an error.  */
+      save_errno = errno;
+      warning ("Cannot exec %s", argv[0]);
+
+      for (i = 1; argv[i] != NULL; i++)
+	warning (" %s", argv[i]);
+
+      warning ("Error: %s\n", safe_strerror (save_errno));
+
+      _exit (0177);
+    }
+
+  /* Restore our environment in case a vforked child clob'd it.  */
+  environ = save_our_env;
+
+  postfork_hook (pid);
+
+  /* Now that we have a child process, make it our target, and
+     initialize anything target-vector-specific that needs
+     initializing.  */
+  if (init_trace_fun)
+    (*init_trace_fun) (pid);
+
+  /* We are now in the child process of interest, having exec'd the
+     correct program, and are poised at the first instruction of the
+     new program.  */
+  return pid;
+}
+
+/* See nat/fork-inferior.h.  */
+
+ptid_t
+startup_inferior (pid_t pid, int ntraps,
+		  struct target_waitstatus *last_waitstatus,
+		  ptid_t *last_ptid)
+{
+  int pending_execs = ntraps;
+  int terminal_initted = 0;
+  ptid_t resume_ptid;
+
+  if (startup_with_shell)
+    {
+      /* One trap extra for exec'ing the shell.  */
+      pending_execs++;
+    }
+
+  if (target_supports_multi_process ())
+    resume_ptid = pid_to_ptid (pid);
+  else
+    resume_ptid = minus_one_ptid;
+
+  /* The process was started by the fork that created it, but it will
+     have stopped one instruction after execing the shell.  Here we
+     must get it up to actual execution of the real program.  */
+  if (get_exec_wrapper () != NULL)
+    pending_execs++;
+
+  while (1)
+    {
+      enum gdb_signal resume_signal = GDB_SIGNAL_0;
+      ptid_t event_ptid;
+
+      struct target_waitstatus ws;
+      memset (&ws, 0, sizeof (ws));
+      event_ptid = target_wait (resume_ptid, &ws, 0);
+
+      if (last_waitstatus != NULL)
+	*last_waitstatus = ws;
+      if (last_ptid != NULL)
+	*last_ptid = event_ptid;
+
+      if (ws.kind == TARGET_WAITKIND_IGNORE)
+	/* The inferior didn't really stop, keep waiting.  */
+	continue;
+
+      switch (ws.kind)
+	{
+	  case TARGET_WAITKIND_SPURIOUS:
+	  case TARGET_WAITKIND_LOADED:
+	  case TARGET_WAITKIND_FORKED:
+	  case TARGET_WAITKIND_VFORKED:
+	  case TARGET_WAITKIND_SYSCALL_ENTRY:
+	  case TARGET_WAITKIND_SYSCALL_RETURN:
+	    /* Ignore gracefully during startup of the inferior.  */
+	    switch_to_thread (event_ptid);
+	    break;
+
+	  case TARGET_WAITKIND_SIGNALLED:
+	    target_terminal_ours ();
+	    target_mourn_inferior (event_ptid);
+	    error (_("During startup program terminated with signal %s, %s."),
+		   gdb_signal_to_name (ws.value.sig),
+		   gdb_signal_to_string (ws.value.sig));
+	    return resume_ptid;
+
+	  case TARGET_WAITKIND_EXITED:
+	    target_terminal_ours ();
+	    target_mourn_inferior (event_ptid);
+	    if (ws.value.integer)
+	      error (_("During startup program exited with code %d."),
+		     ws.value.integer);
+	    else
+	      error (_("During startup program exited normally."));
+	    return resume_ptid;
+
+	  case TARGET_WAITKIND_EXECD:
+	    /* Handle EXEC signals as if they were SIGTRAP signals.  */
+	    xfree (ws.value.execd_pathname);
+	    resume_signal = GDB_SIGNAL_TRAP;
+	    switch_to_thread (event_ptid);
+	    break;
+
+	  case TARGET_WAITKIND_STOPPED:
+	    resume_signal = ws.value.sig;
+	    switch_to_thread (event_ptid);
+	    break;
+	}
+
+      if (resume_signal != GDB_SIGNAL_TRAP)
+	{
+	  /* Let shell child handle its own signals in its own way.  */
+	  target_continue (resume_ptid, resume_signal);
+	}
+      else
+	{
+	  /* We handle SIGTRAP, however; it means child did an exec.  */
+	  if (!terminal_initted)
+	    {
+	      /* Now that the child has exec'd we know it has already
+	         set its process group.  On POSIX systems, tcsetpgrp
+	         will fail with EPERM if we try it before the child's
+	         setpgid.  */
+
+	      /* Set up the "saved terminal modes" of the inferior
+	         based on what modes we are starting it with.  */
+	      target_terminal_init ();
+
+	      /* Install inferior's terminal modes.  */
+	      target_terminal_inferior ();
+
+	      terminal_initted = 1;
+	    }
+
+	  if (--pending_execs == 0)
+	    break;
+
+	  /* Just make it go on.  */
+	  target_continue_no_signal (resume_ptid);
+	}
+    }
+
+  return resume_ptid;
+}
diff --git a/gdb/nat/fork-inferior.h b/gdb/nat/fork-inferior.h
new file mode 100644
index 0000000..39bdd8d
--- /dev/null
+++ b/gdb/nat/fork-inferior.h
@@ -0,0 +1,90 @@ 
+/* Functions and data responsible for forking the inferior process.
+
+   Copyright (C) 1986-2017 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/>.  */
+
+#ifndef FORK_INFERIOR_H
+#define FORK_INFERIOR_H
+
+#include <string>
+
+/* Number of traps that happen between exec'ing the shell to run an
+   inferior and when we finally get to the inferior code, not counting
+   the exec for the shell.  This is 1 on all supported
+   implementations.  */
+#define START_INFERIOR_TRAPS_EXPECTED 1
+
+/* Start an inferior Unix child process and sets inferior_ptid to its
+   pid.  EXEC_FILE is the file to run.  ALLARGS is a string containing
+   the arguments to the program.  ENV is the environment vector to
+   pass.  SHELL_FILE is the shell file, or NULL if we should pick
+   one.  EXEC_FUN is the exec(2) function to use, or NULL for the default
+   one.  */
+
+/* This function is NOT reentrant.  Some of the variables have been
+   made static to ensure that they survive the vfork call.  */
+extern pid_t fork_inferior (const char *exec_file_arg,
+			    const std::string &allargs,
+			    char **env, void (*traceme_fun) (),
+			    void (*init_trace_fun) (int),
+			    void (*pre_trace_fun) (),
+			    const char *shell_file_arg,
+			    void (*exec_fun) (const char *file,
+					      char * const *argv,
+					      char * const *env));
+
+/* Accept NTRAPS traps from the inferior.
+
+   Return the ptid of the inferior being started.  */
+extern ptid_t startup_inferior (pid_t pid, int ntraps,
+				struct target_waitstatus *mystatus,
+				ptid_t *myptid);
+
+/* Whether to start up the debuggee under a shell.
+
+   If startup-with-shell is set, GDB's "run" will attempt to start up
+   the debuggee under a shell.  This also happens when using GDBserver
+   under extended remote mode.
+
+   This is in order for argument-expansion to occur.  E.g.,
+
+   (gdb) run *
+
+   The "*" gets expanded by the shell into a list of files.
+
+   While this is a nice feature, it may be handy to bypass the shell
+   in some cases.  To disable this feature, do "set startup-with-shell
+   false".
+
+   The catch-exec traps expected during start-up will be one more if
+   the target is started up with a shell.  */
+extern int startup_with_shell;
+
+/* Perform any necessary tasks before a fork/vfork takes place.  ARGS
+   is a string containing all the arguments received by the inferior.
+   This function is mainly used by fork_inferior.  */
+extern void prefork_hook (const char *args);
+
+/* Perform any necessary tasks after a fork/vfork takes place.  This
+   function is mainly used by fork_inferior.  */
+extern void postfork_hook (pid_t pid);
+
+/* Perform any necessary tasks *on the child* after a fork/vfork takes
+   place.  This function is mainly used by fork_inferior.  */
+extern void postfork_child_hook ();
+
+#endif /* ! FORK_INFERIOR_H */
diff --git a/gdb/procfs.c b/gdb/procfs.c
index adb2e84..b03809c 100644
--- a/gdb/procfs.c
+++ b/gdb/procfs.c
@@ -4377,7 +4377,7 @@  procfs_init_inferior (struct target_ops *ops, int pid)
   thread_change_ptid (pid_to_ptid (pid),
 		      ptid_build (pid, lwpid, 0));
 
-  startup_inferior (START_INFERIOR_TRAPS_EXPECTED);
+  gdb_startup_inferior (pid, START_INFERIOR_TRAPS_EXPECTED);
 
 #ifdef SYS_syssgi
   /* On mips-irix, we need to stop the inferior early enough during
@@ -4604,6 +4604,11 @@  procfs_create_inferior (struct target_ops *ops, const char *exec_file,
   pid = fork_inferior (exec_file, allargs, env, procfs_set_exec_trap,
 		       NULL, NULL, shell_file, NULL);
 
+  /* We have something that executes now.  We'll be running through
+     the shell at this point (if startup-with-shell is true), but the
+     pid shouldn't change.  */
+  add_thread_silent (pid_to_ptid (pid));
+
   procfs_init_inferior (ops, pid);
 }
 
diff --git a/gdb/target.h b/gdb/target.h
index a971adf..083d2bc 100644
--- a/gdb/target.h
+++ b/gdb/target.h
@@ -1538,16 +1538,8 @@  extern int target_terminal_is_inferior (void);
 
 extern int target_terminal_is_ours (void);
 
-/* Initialize the terminal settings we record for the inferior,
-   before we actually run the inferior.  */
-
-extern void target_terminal_init (void);
-
-/* Put the inferior's terminal settings into effect.  This is
-   preparation for starting or resuming the inferior.  This is a no-op
-   unless called with the main UI as current UI.  */
-
-extern void target_terminal_inferior (void);
+/* For target_terminal_init, target_terminal_inferior and
+   target_terminal_ours, see target/target.h.  */
 
 /* Put some of our terminal settings into effect, enough to get proper
    results from our output, but do not change into or out of RAW mode
@@ -1557,12 +1549,6 @@  extern void target_terminal_inferior (void);
 
 extern void target_terminal_ours_for_output (void);
 
-/* Put our terminal settings into effect.  First record the inferior's
-   terminal settings so they can be restored properly later.  This is
-   a no-op unless called with the main UI as current UI.  */
-
-extern void target_terminal_ours (void);
-
 /* Return true if the target stack has a non-default
   "to_terminal_ours" method.  */
 
diff --git a/gdb/target/target.h b/gdb/target/target.h
index 582852c..0528766 100644
--- a/gdb/target/target.h
+++ b/gdb/target/target.h
@@ -95,4 +95,18 @@  extern void target_mourn_inferior (ptid_t ptid);
 
 extern int target_supports_multi_process (void);
 
+/* Initialize the terminal settings we record for the inferior,
+   before we actually run the inferior.  */
+extern void target_terminal_init ();
+
+/* Put the inferior's terminal settings into effect.  This is
+   preparation for starting or resuming the inferior.  This is a no-op
+   unless called with the main UI as current UI.  */
+extern void target_terminal_inferior ();
+
+/* Put our terminal settings into effect.  First record the inferior's
+   terminal settings so they can be restored properly later.  This is
+   a no-op unless called with the main UI as current UI.  */
+extern void target_terminal_ours ();
+
 #endif /* TARGET_COMMON_H */
diff --git a/gdb/testsuite/gdb.server/non-existing-program.exp b/gdb/testsuite/gdb.server/non-existing-program.exp
index d404564..68d4d53 100644
--- a/gdb/testsuite/gdb.server/non-existing-program.exp
+++ b/gdb/testsuite/gdb.server/non-existing-program.exp
@@ -39,8 +39,16 @@  set spawn_id [remote_spawn target "$gdbserver stdio non-existing-program"]
 set msg "gdbserver exits cleanly"
 set saw_exiting 0
 expect {
-    # This is what we get on ptrace-based targets.
-    -re "stdin/stdout redirected.*No program to debug\r\nExiting\r\n$" {
+    # This is what we get on ptrace-based targets with
+    # startup-with-shell disabled (e.g., when the SHELL variable is
+    # unset).
+    -re "stdin/stdout redirected.*gdbserver: Cannot exec non-existing-program\r\ngdbserver: Error: No such file or directory\r\n\r\nDuring startup program exited with code 127\.\r\nExiting\r\n$" {
+	set saw_exiting 1
+	exp_continue
+    }
+    # Likewise, but with startup-with-shell enabled, which is the
+    # default behaviour.
+    -re "stdin/stdout redirected.*exec: non-existing-program: not found\r\nDuring startup program exited with code 127\.\r\nExiting\r\n$" {
 	set saw_exiting 1
 	exp_continue
     }
diff --git a/gdb/utils.c b/gdb/utils.c
index c61557e..bd0a0d8 100644
--- a/gdb/utils.c
+++ b/gdb/utils.c
@@ -3391,6 +3391,15 @@  strip_leading_path_elements (const char *path, int n)
   return p;
 }
 
+/* See common/common-utils.h.  */
+
+void
+gdb_flush_out_err ()
+{
+  gdb_flush (main_ui->m_gdb_stdout);
+  gdb_flush (main_ui->m_gdb_stderr);
+}
+
 /* Provide a prototype to silence -Wmissing-prototypes.  */
 extern initialize_file_ftype _initialize_utils;