From: Jeff Dike <jdike@addtoit.com>
To: Joshua Hudson <joshudson@gmail.com>
Cc: linux-kernel@vger.kernel.org
Subject: Re: [OT] 'volatile' in userspace
Date: Mon, 10 Jul 2006 14:54:35 -0400 [thread overview]
Message-ID: <20060710185435.GA5445@ccure.user-mode-linux.org> (raw)
In-Reply-To: <bda6d13a0607101000w6ec403bbq7ac0fe66c09c6080@mail.gmail.com>
On Mon, Jul 10, 2006 at 10:00:37AM -0700, Joshua Hudson wrote:
> Yes, I use vfork. So far, the only way I have found for the parent to
> know whether or not the child's exec() failed is this way:
What I do in UML is make a pipe between the parent and child, set it
CLOEXEC, and write a byte down it if the exec fails.
The parent reads it - if it gets no bytes, the exec succeeded, if it
gets one byte, it failed.
child -
execvp(argv[0], argv);
errval = errno;
write(data->fd, &errval, sizeof(errval));
parent -
socketpair(AF_UNIX, SOCK_STREAM, 0, fds);
fcntl(fds[1], F_SETFD, flag);
pid = clone(child, NULL, SIGCHLD, NULL);
if(pid < 0){
...
}
close(fds[1]);
/* Read the errno value from the child, if the exec failed, or get 0 if
* the exec succeeded because the pipe fd was set as close-on-exec.
*/
n = read(fds[0], &ret, sizeof(ret));
if (n < 0) {
} else if(n != 0){
/* exec failed */
} else {
/* exec succeeded */
}
Jeff
next prev parent reply other threads:[~2006-07-10 18:54 UTC|newest]
Thread overview: 133+ messages / expand[flat|nested] mbox.gz Atom feed top
2006-07-05 8:49 [patch] uninline init_waitqueue_*() functions Ingo Molnar
2006-07-05 9:31 ` Andrew Morton
2006-07-05 9:32 ` Ingo Molnar
2006-07-05 9:53 ` Andrew Morton
2006-07-05 10:26 ` Ingo Molnar
2006-07-05 11:30 ` Ingo Molnar
2006-07-05 11:46 ` Ingo Molnar
2006-07-05 17:10 ` Andrew Morton
2006-07-05 19:35 ` Ingo Molnar
2006-07-05 20:18 ` Andrew Morton
2006-07-05 20:36 ` Linus Torvalds
2006-07-05 20:47 ` Ingo Molnar
2006-07-05 21:15 ` Ingo Molnar
2006-07-05 21:21 ` Linus Torvalds
2006-07-05 21:45 ` Ingo Molnar
2006-07-05 21:58 ` Randy.Dunlap
2006-07-05 22:00 ` Ingo Molnar
2006-07-05 22:10 ` Randy.Dunlap
2006-07-05 22:27 ` Ingo Molnar
2006-07-05 23:15 ` Adrian Bunk
2006-07-05 22:09 ` Linus Torvalds
2006-07-05 22:30 ` Ingo Molnar
2006-07-05 23:11 ` Linus Torvalds
2006-07-06 8:16 ` [patch] spinlocks: remove 'volatile' Ingo Molnar
2006-07-06 8:23 ` Ingo Molnar
2006-07-06 9:27 ` Heiko Carstens
2006-07-06 9:34 ` Arjan van de Ven
2006-07-06 11:59 ` linux-os (Dick Johnson)
2006-07-06 12:01 ` Arjan van de Ven
2006-07-06 12:29 ` linux-os (Dick Johnson)
2006-07-06 12:39 ` Arjan van de Ven
2006-07-06 13:39 ` J.A. Magallón
2006-07-06 13:43 ` Arjan van de Ven
2006-07-06 14:05 ` Chase Venters
2006-07-06 14:26 ` Andreas Schwab
2006-07-06 16:40 ` Nick Piggin
2006-07-06 23:19 ` David Schwartz
2006-07-06 18:15 ` Mark Lord
2006-07-06 19:15 ` Linus Torvalds
2006-07-06 19:33 ` Chris Friesen
2006-07-06 19:37 ` Mark Lord
2006-07-06 20:28 ` Chris Friesen
2006-07-06 20:32 ` Linus Torvalds
2006-07-06 19:38 ` Arjan van de Ven
2006-07-06 19:41 ` Måns Rullgård
2006-07-06 19:42 ` Jeff Garzik
2006-07-06 19:58 ` Linus Torvalds
2006-07-06 20:27 ` Mark Lord
2006-07-06 20:40 ` Chris Friesen
2006-07-06 21:00 ` Linus Torvalds
2006-07-08 8:40 ` Avi Kivity
2006-07-08 8:51 ` Arjan van de Ven
2006-07-08 9:20 ` Avi Kivity
2006-07-08 9:51 ` Arjan van de Ven
2006-07-08 10:18 ` Avi Kivity
2006-07-08 10:28 ` Thomas Gleixner
2006-07-09 4:19 ` Benjamin Herrenschmidt
2006-07-09 12:47 ` Avi Kivity
2006-07-09 19:16 ` David Schwartz
2006-07-09 19:51 ` Theodore Tso
2006-07-09 20:40 ` [OT] 'volatile' in userspace Rutger Nijlunsing
2006-07-10 3:42 ` Theodore Tso
2006-07-10 17:00 ` Joshua Hudson
2006-07-10 17:54 ` Nick Piggin
2006-07-11 7:48 ` Jan Engelhardt
2006-07-11 11:53 ` Nick Piggin
2006-07-11 19:09 ` Björn Steinbrink
2006-07-11 20:55 ` Jeff Dike
2006-07-10 18:54 ` Jeff Dike [this message]
2006-07-10 20:09 ` Philippe Troin
2006-07-10 20:52 ` Jeff Dike
2006-07-06 16:07 ` [patch] spinlocks: remove 'volatile' Linus Torvalds
2006-07-06 16:13 ` Linus Torvalds
2006-07-06 17:04 ` Jeff Garzik
2006-07-06 17:52 ` linux-os (Dick Johnson)
2006-07-06 18:00 ` Linus Torvalds
2006-07-06 21:02 ` J.A. Magallón
2006-07-06 21:12 ` Linus Torvalds
2006-07-06 18:10 ` Michael Buesch
2006-07-06 18:16 ` Chase Venters
2006-07-07 18:16 ` Krzysztof Halasa
2006-07-07 19:51 ` linux-os (Dick Johnson)
2006-07-07 20:25 ` Linus Torvalds
2006-07-07 21:22 ` linux-os (Dick Johnson)
2006-07-07 21:48 ` Chase Venters
2006-07-08 10:00 ` Krzysztof Halasa
2006-07-08 13:41 ` Chase Venters
2006-07-08 20:09 ` Krzysztof Halasa
2006-07-08 20:40 ` Chase Venters
2006-07-08 20:47 ` Chase Venters
2006-07-09 10:57 ` Krzysztof Halasa
2006-07-07 21:59 ` Linus Torvalds
2006-07-07 22:06 ` Linus Torvalds
2006-07-08 20:49 ` Pavel Machek
2006-07-08 21:43 ` Linus Torvalds
2006-07-07 22:05 ` J.A. Magallón
2006-07-07 22:22 ` Chase Venters
2006-07-07 22:37 ` J.A. Magallón
2006-07-08 9:33 ` David Schwartz
2006-07-07 22:49 ` J.A. Magallón
2006-07-07 22:59 ` Vadim Lobanov
2006-07-07 23:18 ` Chase Venters
2006-07-07 23:36 ` Davide Libenzi
2006-07-07 22:09 ` Ingo Molnar
2006-07-08 7:36 ` Ingo Molnar
2006-07-07 20:39 ` Krzysztof Halasa
2006-07-07 23:06 ` Björn Steinbrink
2006-07-08 8:36 ` Avi Kivity
2006-07-06 19:32 ` Jan Engelhardt
2006-07-06 20:26 ` Jeremy Fitzhardinge
2006-07-06 20:55 ` Jan Engelhardt
2006-07-06 21:07 ` Linus Torvalds
2006-07-06 19:56 ` Linus Torvalds
2006-07-06 20:34 ` Linus Torvalds
2006-07-08 22:50 ` Ralf Baechle
2006-07-09 3:09 ` Linus Torvalds
2006-07-09 3:07 ` Keith Owens
2006-07-09 3:29 ` Linus Torvalds
2006-07-09 3:43 ` Keith Owens
2006-07-09 3:58 ` Linus Torvalds
2006-07-09 6:13 ` David Miller
2006-07-09 14:28 ` Roman Zippel
2006-07-09 15:27 ` Linus Torvalds
2006-07-06 8:18 ` [patch] lockdep: clean up completion initializer in smpboot.c Ingo Molnar
2006-07-06 8:23 ` [patch] uninline init_waitqueue_*() functions Ingo Molnar
2006-07-06 9:02 ` Andrew Morton
2006-07-06 9:12 ` [patch] uninline init_waitqueue_head() Ingo Molnar
2006-07-05 20:45 ` [patch] uninline init_waitqueue_*() functions Ingo Molnar
2006-07-05 10:37 ` Christoph Hellwig
2006-07-05 10:44 ` Andrew Morton
2006-07-05 10:46 ` Andrew Morton
2006-07-05 10:47 ` Ingo Molnar
2006-07-05 9:54 ` [patch] uninline init_waitqueue_*() functions, fix Ingo Molnar
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