* Does init start with any open files?
@ 2012-12-25 7:38 bbi5291
2012-12-25 11:17 ` Borislav Petkov
` (2 more replies)
0 siblings, 3 replies; 6+ messages in thread
From: bbi5291 @ 2012-12-25 7:38 UTC (permalink / raw)
To: linux-kernel
When the init process is created on system startup, does it have any
open file descriptors? If so, where do they point?
________________________________
Brian Bi
^ permalink raw reply [flat|nested] 6+ messages in thread* Re: Does init start with any open files? 2012-12-25 7:38 Does init start with any open files? bbi5291 @ 2012-12-25 11:17 ` Borislav Petkov 2012-12-25 11:25 ` bbi5291 2012-12-25 13:38 ` Miquel van Smoorenburg 2012-12-25 21:40 ` Rob Landley 2 siblings, 1 reply; 6+ messages in thread From: Borislav Petkov @ 2012-12-25 11:17 UTC (permalink / raw) To: bbi5291; +Cc: linux-kernel On Tue, Dec 25, 2012 at 02:38:09AM -0500, bbi5291 wrote: > When the init process is created on system startup, does it have any > open file descriptors? If so, where do they point? $ tree /proc/1/fd /proc/1/fd └── 10 -> /run/initctl 0 directories, 1 file -- Regards/Gruss, Boris. Sent from a fat crate under my desk. Formatting is fine. -- ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: Does init start with any open files? 2012-12-25 11:17 ` Borislav Petkov @ 2012-12-25 11:25 ` bbi5291 2012-12-25 11:58 ` Borislav Petkov 0 siblings, 1 reply; 6+ messages in thread From: bbi5291 @ 2012-12-25 11:25 UTC (permalink / raw) To: Borislav Petkov, bbi5291, linux-kernel Well, that can't be right---I grepped the kernel source for "initctl" and got no results. Besides, if you're running a shell, then init has already had time to open and close whatever file descriptors it wants to. What I want to know is whether init has any open file descriptors, at, say, the moment its main() starts executing. ________________________________ Brian Bi On Tue, Dec 25, 2012 at 6:17 AM, Borislav Petkov <bp@alien8.de> wrote: > On Tue, Dec 25, 2012 at 02:38:09AM -0500, bbi5291 wrote: >> When the init process is created on system startup, does it have any >> open file descriptors? If so, where do they point? > > $ tree /proc/1/fd > /proc/1/fd > └── 10 -> /run/initctl > > 0 directories, 1 file > > -- > Regards/Gruss, > Boris. > > Sent from a fat crate under my desk. Formatting is fine. > -- ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: Does init start with any open files? 2012-12-25 11:25 ` bbi5291 @ 2012-12-25 11:58 ` Borislav Petkov 0 siblings, 0 replies; 6+ messages in thread From: Borislav Petkov @ 2012-12-25 11:58 UTC (permalink / raw) To: bbi5291; +Cc: linux-kernel First of all, please do not top-post. You can search the net for why top-posting is discouraged. On Tue, Dec 25, 2012 at 06:25:11AM -0500, bbi5291 wrote: > Well, that can't be right---I grepped the kernel source for "initctl" > and got no results. That's because it is a named pipe. > Besides, if you're running a shell, then init has already had time > to open and close whatever file descriptors it wants to. What I want > to know is whether init has any open file descriptors, at, say, the > moment its main() starts executing. You probably want to stare at init/main.c:kernel_init() and what it calls, and then download the sources of the init executable which is run on your distro, whip up a text editor and start staring at them. HTH. -- Regards/Gruss, Boris. Sent from a fat crate under my desk. Formatting is fine. -- ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: Does init start with any open files? 2012-12-25 7:38 Does init start with any open files? bbi5291 2012-12-25 11:17 ` Borislav Petkov @ 2012-12-25 13:38 ` Miquel van Smoorenburg 2012-12-25 21:40 ` Rob Landley 2 siblings, 0 replies; 6+ messages in thread From: Miquel van Smoorenburg @ 2012-12-25 13:38 UTC (permalink / raw) To: bbi5291; +Cc: linux-kernel In article <xs4all.CAMmfjbPKGD28070A0JvMyL02juYW5tuwNmVwrJ-1gFzkNhCuDQ@mail.gmail.com> you write: >When the init process is created on system startup, does it have any >open file descriptors? If so, where do they point? 0, 1 and 2, which are connected to the console. Boot a kernel with "init=/bin/bash" and see for yourself. Mike. ^ permalink raw reply [flat|nested] 6+ messages in thread
* Re: Does init start with any open files? 2012-12-25 7:38 Does init start with any open files? bbi5291 2012-12-25 11:17 ` Borislav Petkov 2012-12-25 13:38 ` Miquel van Smoorenburg @ 2012-12-25 21:40 ` Rob Landley 2 siblings, 0 replies; 6+ messages in thread From: Rob Landley @ 2012-12-25 21:40 UTC (permalink / raw) To: bbi5291; +Cc: linux-kernel On 12/25/2012 01:38:09 AM, bbi5291 wrote: > When the init process is created on system startup, does it have any > open file descriptors? If so, where do they point? Last I checked, it worked like this: If there's a /dev/console in initramfs, stdin, stdout, and stderr will point to that. If you select no initramfs, you get one with just /dev/console. If you create your own initramfs and don't put /dev/console in it, init gets no file descriptors and there's a line about it in dmesg. Rob ^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2012-12-25 21:40 UTC | newest] Thread overview: 6+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2012-12-25 7:38 Does init start with any open files? bbi5291 2012-12-25 11:17 ` Borislav Petkov 2012-12-25 11:25 ` bbi5291 2012-12-25 11:58 ` Borislav Petkov 2012-12-25 13:38 ` Miquel van Smoorenburg 2012-12-25 21:40 ` Rob Landley
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