From: Brice Goglin <Brice.Goglin@ens-lyon.fr>
To: Luke Kenneth Casson Leighton <lkcl@lkcl.net>
Cc: linux-kernel@vger.kernel.org
Subject: Re: how do you call userspace syscalls (e.g. sys_rename) from inside kernel
Date: Fri, 08 Oct 2004 17:18:40 +0200 [thread overview]
Message-ID: <4166AFD0.2020905@ens-lyon.fr> (raw)
In-Reply-To: <20041008151837.GI5551@lkcl.net>
> call sys_rename, sys_pread, sys_create, sys_mknod, sys_rmdir
> etc. - everything that does file access.
If you ever actually call sys_this or sys_that ... from
the kernel, you'll have to do something like this to avoid
copy_from/to_user to fail because the target buffer is not
in kernel space:
mm_segment_t old_fs;
old_fs = get_fs();
set_fs(KERNEL_DS);
<do you stuff here>
set_fs(old_fs);
Just look for set_fs in the kernel source to find examples.
--
Brice Goglin
================================================
Ph.D Student
Laboratoire de l'Informatique et du Parallélisme
CNRS-ENS Lyon-INRIA-UCB Lyon
France
next prev parent reply other threads:[~2004-10-08 15:20 UTC|newest]
Thread overview: 20+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-10-08 13:04 how do you call userspace syscalls (e.g. sys_rename) from inside kernel Luke Kenneth Casson Leighton
2004-10-08 13:07 ` Fabiano Ramos
2004-10-08 13:38 ` Brice Goglin
2004-10-08 15:04 ` Fabiano Ramos
2004-10-08 15:35 ` Luke Kenneth Casson Leighton
2004-10-08 14:02 ` Brian Gerst
2004-10-08 15:18 ` Luke Kenneth Casson Leighton
2004-10-08 15:12 ` Bernd Petrovitsch
2004-10-08 17:03 ` Luke Kenneth Casson Leighton
2004-10-08 15:18 ` Brice Goglin [this message]
2004-10-08 16:20 ` Luke Kenneth Casson Leighton
2004-10-08 16:37 ` Jan-Benedict Glaw
2004-10-08 17:37 ` Luke Kenneth Casson Leighton
2004-10-08 15:27 ` Brian Gerst
2004-10-08 17:04 ` Luke Kenneth Casson Leighton
2004-10-12 0:15 ` Jon Masters
2004-10-12 13:16 ` Luke Kenneth Casson Leighton
-- strict thread matches above, loose matches on Subject: below --
2004-10-10 23:13 Aboo Valappil
2004-10-10 23:35 ` Arnd Bergmann
2004-10-11 9:56 ` Jirka Kosina
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