[v3,BZ,21340] add support for POSIX_SPAWN_SETSID
Commit Message
On 21/04/2017 11:24, Florian Weimer wrote:
> 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
I think this iteration should fix the issues you bring.
--
Daurnimator <quae@daurnimator.com>
Adhemerval Zanella <adhemerval.zanella@linaro.org>
[BZ #21340]
* 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.
---
Comments
On Fri, 21 Apr 2017, Adhemerval Zanella wrote:
> I think this iteration should fix the issues you bring.
>
> --
>
> Daurnimator <quae@daurnimator.com>
> Adhemerval Zanella <adhemerval.zanella@linaro.org>
>
> [BZ #21340]
> * 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.
I think you should also add a NEWS entry for the new feature.
* Adhemerval Zanella:
> +static int
> +do_test_setsid (bool test_setsid)
This should return void.
> + if (test_setsid)
> + {
> + if (posix_spawnattr_setflags (&attrp, POSIX_SPAWN_SETSID))
> + FAIL_EXIT1 ("posix_spawnattr_setflags: %m");
> + }
You need to set errno before you can use %m.
> + 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");
Likewise.
> +static int
> +do_test (void)
> +{
> + int ret = 0;
> +
> + ret += do_test_setsid (false);
> + ret += do_test_setsid (true);
> +
> + return 0;
> +}
ret is effectively unused.
> 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
> + if ((attr->__flags & POSIX_SPAWN_SETSID) != 0
> + && (ret = __setsid ()) < 0)
> + goto fail;
I believe the assignment to ret is dead.
> +
> /* Set the process group ID. */
> if ((attr->__flags & POSIX_SPAWN_SETPGROUP) != 0
> && (ret = __setpgid (0, attr->__pgrp)) != 0)
Apparently, this is an existing problem with the code ...
On 21/04/2017 17:04, Florian Weimer wrote:
> * Adhemerval Zanella:
>
>> +static int
>> +do_test_setsid (bool test_setsid)
>
> This should return void.
Ack.
>
>> + if (test_setsid)
>> + {
>> + if (posix_spawnattr_setflags (&attrp, POSIX_SPAWN_SETSID))
>> + FAIL_EXIT1 ("posix_spawnattr_setflags: %m");
>> + }
>
> You need to set errno before you can use %m.
Ack.
>
>> + 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");
>
> Likewise.
Ack.
>
>> +static int
>> +do_test (void)
>> +{
>> + int ret = 0;
>> +
>> + ret += do_test_setsid (false);
>> + ret += do_test_setsid (true);
>> +
>> + return 0;
>> +}
>
> ret is effectively unused.
Yeah, I though about doing that since we bail out with an exit for
failure. I will change it.
>
>> 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
>
>> + if ((attr->__flags & POSIX_SPAWN_SETSID) != 0
>> + && (ret = __setsid ()) < 0)
>> + goto fail;
>
> I believe the assignment to ret is dead.
>
>> +
>> /* Set the process group ID. */
>> if ((attr->__flags & POSIX_SPAWN_SETPGROUP) != 0
>> && (ret = __setpgid (0, attr->__pgrp)) != 0)
>
> Apparently, this is an existing problem with the code ...
>
If I recall correctly, on initial iterations for posix_spawn rewrite I used the ret
return to signal the error, but it seems later I generalize to use errno instead.
I will fix this usage, but I think extra fixes should go to on a different patch.
On 21/04/2017 16:53, Joseph Myers wrote:
> On Fri, 21 Apr 2017, Adhemerval Zanella wrote:
>
>> I think this iteration should fix the issues you bring.
>>
>> --
>>
>> Daurnimator <quae@daurnimator.com>
>> Adhemerval Zanella <adhemerval.zanella@linaro.org>
>>
>> [BZ #21340]
>> * 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.
>
> I think you should also add a NEWS entry for the new feature.
>
I will add one.
* Adhemerval Zanella:
> I will fix this usage, but I think extra fixes should go to on a
> different patch.
Thanks, and agreed.
@@ -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))
@@ -59,6 +59,7 @@ typedef struct
#define POSIX_SPAWN_SETSCHEDULER 0x20
#ifdef __USE_GNU
# define POSIX_SPAWN_USEVFORK 0x40
+# define POSIX_SPAWN_SETSID 0x80
#endif
@@ -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. */
new file mode 100644
@@ -0,0 +1,92 @@
+/* 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_setsid (bool test_setsid)
+{
+ 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 should not fail (it basically memset the
+ attribute). */
+ posix_spawnattr_init (&attrp);
+ if (test_setsid)
+ {
+ 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 (test_setsid)
+ {
+ if (child_sid == sid)
+ FAIL_EXIT1 ("child session ID matched parent one");
+ }
+ else
+ {
+ if (child_sid != sid)
+ FAIL_EXIT1 ("child session ID did not match parent one");
+ }
+
+ return 0;
+}
+
+static int
+do_test (void)
+{
+ int ret = 0;
+
+ ret += do_test_setsid (false);
+ ret += do_test_setsid (true);
+
+ return 0;
+}
+
+#include <support/test-driver.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);
@@ -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)
@@ -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)