[v3,BZ,21340] add support for POSIX_SPAWN_SETSID

Submitted by Adhemerval Zanella on April 21, 2017, 2:13 p.m.

Details

Message ID a76bbb82-02c8-95fc-d49f-7f474f9179c2@linaro.org
State New
Headers show

Commit Message

Adhemerval Zanella April 21, 2017, 2:13 p.m.
On 21/04/2017 02:03, Daurnimator wrote:
> On 9 April 2017 at 23:21, Daurnimator <quae@daurnimator.com> wrote:
>> On 6 April 2017 at 22:37, Florian Weimer <fweimer@redhat.com> wrote:
>>> Would you be willing to assign copyright for this and future changes?
>>>
>>> If yes, please pick request-assign.future from here:
>>>
>>> <https://sourceware.org/glibc/wiki/Contribution%20checklist#FSF_copyright_Assignment>
>>>
>>> and send the filled-out form to <assign@gnu.org>.  As far as I understand
>>> it, citizens from most countries can complete the process electronically
>>> these days.
>>
>> Sorry, but I'm not willing to link my legal name to this pseudonym.
>>
>> Please still consider merging my changes (as they should be uncopyrightable).
>> However as I understand it, you will have to re-write the test case.
> 
> I'd still love to get this patch merged; is someone willing to rewrite
> the test case?
> 

What about now? I have adjusted the testcase using support library and
fixed some nits in ChangeLog.

--

	Daurnimator  <quae@daurnimator.com>
	Adhemerval Zanella  <adhemerval.zanella@linaro.org>

	[BZ #21340]
	* conform/data/spawn.h-data: Add POSIX_SPAWN_SETSID flag.
	* posix/Makefile (tests): Add tst-posix_spawn-setsid to list of tests.
	* posix/spawn.h: define POSIX_SPAWN_SETSID flag.
	* posix/spawnattr_setflags.c (ALL_FLAGS): Add POSIX_SPAWN_SETSID to
	valid flags.
	* posix/tst-posix_spawn-setsid.c: Add test for POSIX_SPAWN_SETSID.
	* sysdeps/mach/hurd/spawni.c (__spawni): Implementation of
	POSIX_SPAWN_SETSID.
	* sysdeps/posix/spawni.c (__spawni): Likewise.
	* sysdeps/unix/sysv/linux/spawni.c (__spawni_child): Likewise.
---
 ChangeLog                        | 15 +++++++++
 conform/data/spawn.h-data        |  1 +
 posix/Makefile                   |  2 +-
 posix/spawn.h                    |  1 +
 posix/spawnattr_setflags.c       |  1 +
 posix/tst-posix_spawn-setsid.c   | 68 ++++++++++++++++++++++++++++++++++++++++
 sysdeps/mach/hurd/spawni.c       |  3 ++
 sysdeps/posix/spawni.c           |  7 ++++-
 sysdeps/unix/sysv/linux/spawni.c |  4 +++
 9 files changed, 100 insertions(+), 2 deletions(-)
 create mode 100644 posix/tst-posix_spawn-setsid.c

Comments

Florian Weimer April 21, 2017, 2:24 p.m.
On 04/21/2017 04:13 PM, Adhemerval Zanella wrote:

> 	* conform/data/spawn.h-data: Add POSIX_SPAWN_SETSID flag.

I think this has to go away ...


> diff --git a/posix/spawn.h b/posix/spawn.h
> index 36e3867..8d2ace1 100644
> --- a/posix/spawn.h
> +++ b/posix/spawn.h
> @@ -60,6 +60,7 @@ typedef struct
>   #ifdef __USE_GNU
>   # define POSIX_SPAWN_USEVFORK		0x40
>   #endif
> +#define POSIX_SPAWN_SETSID		0x80


... because this has to be governed by __GNU_SOURCE.

> +static int
> +do_test (void)
> +{
> +  pid_t sid, child_sid;
> +  int res;
> +
> +  /* Current session ID.  */
> +  sid = getsid(0);
> +  if (sid == (pid_t) -1)
> +    FAIL_EXIT1 ("getsid (0): %m");
> +
> +  posix_spawnattr_t attrp;
> +  posix_spawnattr_init (&attrp);
> +  if (posix_spawnattr_setflags (&attrp, POSIX_SPAWN_SETSID))
> +    FAIL_EXIT1 ("posix_spawnattr_setflags: %m");

Please run the test twice, once with setting POSIX_SPAWN_SETSID, and 
once without.

Thanks,
Florian
Joseph S. Myers April 21, 2017, 3:45 p.m.
On Fri, 21 Apr 2017, Adhemerval Zanella wrote:

> 	* conform/data/spawn.h-data: Add POSIX_SPAWN_SETSID flag.

See my previous comments.  http://austingroupbugs.net/view.php?id=1044 has 
the issue8 tag - this is *not* a bug fix to the standard for a future TC 
(which would be applied unconditionally to the headers and expectations), 
it's a new feature for the next major POSIX revision, so does not go in 
conform/ expectations until such a revision exists (at which point it 
would be appropriately conditional in those expectations) and is 
conditioned on __USE_GNU until such a revision exists (at which point it 
would be conditional on the feature test macros for the new revision).
Adhemerval Zanella April 21, 2017, 6:17 p.m.
On 21/04/2017 12:45, Joseph Myers wrote:
> On Fri, 21 Apr 2017, Adhemerval Zanella wrote:
> 
>> 	* conform/data/spawn.h-data: Add POSIX_SPAWN_SETSID flag.
> 
> See my previous comments.  http://austingroupbugs.net/view.php?id=1044 has 
> the issue8 tag - this is *not* a bug fix to the standard for a future TC 
> (which would be applied unconditionally to the headers and expectations), 
> it's a new feature for the next major POSIX revision, so does not go in 
> conform/ expectations until such a revision exists (at which point it 
> would be appropriately conditional in those expectations) and is 
> conditioned on __USE_GNU until such a revision exists (at which point it 
> would be conditional on the feature test macros for the new revision).
> 

Thanks for the point, Florian has also brought it to my attention and
I have sent an updated patch (which I can't get a link due sourceware.org
outage).

Patch hide | download patch | download mbox

diff --git a/conform/data/spawn.h-data b/conform/data/spawn.h-data
index fb206f7..bcba36c 100644
--- a/conform/data/spawn.h-data
+++ b/conform/data/spawn.h-data
@@ -14,6 +14,7 @@  constant POSIX_SPAWN_SETSCHEDPARAM
 constant POSIX_SPAWN_SETSCHEDULER
 constant POSIX_SPAWN_SETSIGDEF
 constant POSIX_SPAWN_SETSIGMASK
+constant POSIX_SPAWN_SETSID
 
 function int posix_spawnattr_destroy (posix_spawnattr_t*)
 function int posix_spawnattr_getsigdefault (const posix_spawnattr_t*, sigset_t*)
diff --git a/posix/Makefile b/posix/Makefile
index a6586ea..0fc509c 100644
--- a/posix/Makefile
+++ b/posix/Makefile
@@ -91,7 +91,7 @@  tests		:= test-errno tstgetopt testfnm runtests runptests \
 		   bug-getopt5 tst-getopt_long1 bug-regex34 bug-regex35 \
 		   tst-pathconf tst-getaddrinfo4 tst-rxspencer-no-utf8 \
 		   tst-fnmatch3 bug-regex36 tst-getaddrinfo5 \
-		   tst-posix_spawn-fd \
+		   tst-posix_spawn-fd tst-posix_spawn-setsid \
 		   tst-posix_fadvise tst-posix_fadvise64
 xtests		:= bug-ga2
 ifeq (yes,$(build-shared))
diff --git a/posix/spawn.h b/posix/spawn.h
index 36e3867..8d2ace1 100644
--- a/posix/spawn.h
+++ b/posix/spawn.h
@@ -60,6 +60,7 @@  typedef struct
 #ifdef __USE_GNU
 # define POSIX_SPAWN_USEVFORK		0x40
 #endif
+#define POSIX_SPAWN_SETSID		0x80
 
 
 __BEGIN_DECLS
diff --git a/posix/spawnattr_setflags.c b/posix/spawnattr_setflags.c
index 9b3d1e0..62d2f00 100644
--- a/posix/spawnattr_setflags.c
+++ b/posix/spawnattr_setflags.c
@@ -25,6 +25,7 @@ 
 		   | POSIX_SPAWN_SETSIGMASK				      \
 		   | POSIX_SPAWN_SETSCHEDPARAM				      \
 		   | POSIX_SPAWN_SETSCHEDULER				      \
+		   | POSIX_SPAWN_SETSID					      \
 		   | POSIX_SPAWN_USEVFORK)
 
 /* Store flags in the attribute structure.  */
diff --git a/posix/tst-posix_spawn-setsid.c b/posix/tst-posix_spawn-setsid.c
new file mode 100644
index 0000000..246b39f
--- /dev/null
+++ b/posix/tst-posix_spawn-setsid.c
@@ -0,0 +1,68 @@ 
+/* Test posix_spawn setsid attribute.
+   Copyright (C) 2017 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+
+   The GNU C Library is free software; you can redistribute it and/or
+   modify it under the terms of the GNU Lesser General Public
+   License as published by the Free Software Foundation; either
+   version 2.1 of the License, or (at your option) any later version.
+
+   The GNU C Library 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
+   Lesser General Public License for more details.
+
+   You should have received a copy of the GNU Lesser General Public
+   License along with the GNU C Library; if not, see
+   <http://www.gnu.org/licenses/>.  */
+
+#include <errno.h>
+#include <fcntl.h>
+#include <spawn.h>
+#include <stdbool.h>
+#include <stdio.h>
+#include <sys/resource.h>
+#include <unistd.h>
+
+#include <support/check.h>
+
+static int
+do_test (void)
+{
+  pid_t sid, child_sid;
+  int res;
+
+  /* Current session ID.  */
+  sid = getsid(0);
+  if (sid == (pid_t) -1)
+    FAIL_EXIT1 ("getsid (0): %m");
+
+  posix_spawnattr_t attrp;
+  posix_spawnattr_init (&attrp);
+  if (posix_spawnattr_setflags (&attrp, POSIX_SPAWN_SETSID))
+    FAIL_EXIT1 ("posix_spawnattr_setflags: %m");
+
+  /* Program to run.  */
+  char *args[2] = { (char *) "true", NULL };
+  pid_t child;
+
+  res = posix_spawnp (&child, "true", NULL, &attrp, args, environ);
+  /* posix_spawnattr_destroy is noop.  */
+  posix_spawnattr_destroy (&attrp);
+
+  if (res != 0)
+    FAIL_EXIT1 ("posix_spawnp: %m");
+
+  /* Child should have a different session ID than parent.  */
+  child_sid = getsid (child);
+
+  if (child_sid == (pid_t) -1)
+    FAIL_EXIT1 ("getsid (%i): %m", child);
+
+  if (child_sid == sid)
+    FAIL_EXIT1 ("child sid matches parent one");
+
+  return 0;
+}
+
+#include <support/test-driver.c>
diff --git a/sysdeps/mach/hurd/spawni.c b/sysdeps/mach/hurd/spawni.c
index 284875a..7430383 100644
--- a/sysdeps/mach/hurd/spawni.c
+++ b/sysdeps/mach/hurd/spawni.c
@@ -281,6 +281,9 @@  __spawni (pid_t *pid, const char *file,
     }
 #endif
 
+  if (!err && (flags & POSIX_SPAWN_SETSID) != 0)
+    err = __proc_setsid (proc);
+
   /* Set the process group ID.  */
   if (!err && (flags & POSIX_SPAWN_SETPGROUP) != 0)
     err = __proc_setpgrp (proc, new_pid, attrp->__pgrp);
diff --git a/sysdeps/posix/spawni.c b/sysdeps/posix/spawni.c
index 5cc2ad1..9cad25c 100644
--- a/sysdeps/posix/spawni.c
+++ b/sysdeps/posix/spawni.c
@@ -101,7 +101,8 @@  __spawni (pid_t *pid, const char *file,
 	 to POSIX.  */
       || ((flags & (POSIX_SPAWN_SETSIGMASK | POSIX_SPAWN_SETSIGDEF
 		    | POSIX_SPAWN_SETSCHEDPARAM | POSIX_SPAWN_SETSCHEDULER
-		    | POSIX_SPAWN_SETPGROUP | POSIX_SPAWN_RESETIDS)) == 0
+		    | POSIX_SPAWN_SETPGROUP | POSIX_SPAWN_RESETIDS
+		    | POSIX_SPAWN_SETSID)) == 0
 	  && file_actions == NULL))
     new_pid = __vfork ();
   else
@@ -159,6 +160,10 @@  __spawni (pid_t *pid, const char *file,
     }
 #endif
 
+  if ((flags & POSIX_SPAWN_SETSID) != 0
+      && __setsid () < 0)
+    _exit (SPAWN_ERROR);
+
   /* Set the process group ID.  */
   if ((flags & POSIX_SPAWN_SETPGROUP) != 0
       && __setpgid (0, attrp->__pgrp) != 0)
diff --git a/sysdeps/unix/sysv/linux/spawni.c b/sysdeps/unix/sysv/linux/spawni.c
index d7f9e83..3cf77d5 100644
--- a/sysdeps/unix/sysv/linux/spawni.c
+++ b/sysdeps/unix/sysv/linux/spawni.c
@@ -177,6 +177,10 @@  __spawni_child (void *arguments)
     }
 #endif
 
+  if ((attr->__flags & POSIX_SPAWN_SETSID) != 0
+      && (ret = __setsid ()) < 0)
+    goto fail;
+
   /* Set the process group ID.  */
   if ((attr->__flags & POSIX_SPAWN_SETPGROUP) != 0
       && (ret = __setpgid (0, attr->__pgrp)) != 0)