hi peter did you ever gave a try to ctags in 'alliance' with vim? just a hint ... http://scottr.org/blog/2008/feb/24/ctags-and-vim/ have fun TR Am Dienstag, den 24.02.2009, 11:44 -0500 schrieb Peter Teoh: > On Tue, Feb 24, 2009 at 3:38 AM, Thomas Petazzoni > <thomas.petazzoni@xxxxxxxxxxxxxxxxxx> wrote: > > Le Tue, 24 Feb 2009 09:11:53 +0800, > > Peter Teoh <htmldeveloper@xxxxxxxxx> a écrit : > > > >> But then it also puzzled me, because ioctl() in user space required a > >> open file descriptor as the first parameter, which is derived from > >> open() (as specified from "man ioctl"). so then how is the open() > >> from userspace passed down to kernel? > > > > When userspace uses the open() system call, the kernel function > > sys_open() gets called. This kernel function does all the job, and > > calls the ->open() operation of the device driver if it exists. > > Otherwise, it just doesn't call it, and it works perfectly fine. The > > sys_open() function does all what's needed, the ->open() operation is > > only here *if* your device driver needs to do something when the device > > is opened. This operation is optional. > > > > sys_open() > > http://lxr.free-electrons.com/source/fs/open.c#L1032 > > > > calls > > > > do_sys_open() > > http://lxr.free-electrons.com/source/fs/open.c#L1010 > > > > which calls > > > > do_filp_open() > > http://lxr.free-electrons.com/source/fs/namei.c#L1637 > > > > which calls > > > > nameidata_to_filp() > > http://lxr.free-electrons.com/source/fs/open.c#L918 > > > > which calls > > > > __dentry_open() > > http://lxr.free-electrons.com/source/fs/open.c#L793 > > > > which does > > > > 823 if (!open && f->f_op) > > 824 open = f->f_op->open; > > 825 if (open) { > > 826 error = open(inode, f); > > 827 if (error) > > 828 goto cleanup_all; > > 829 } > > > > (ouf) > > > > Sincerly, > > > > Thomas > > Thank you Thomas, I think the lxr source code navigator is really > useful, as compared with "vi" :-). Thank you for the contribution > :-). > -- To unsubscribe from this list: send an email with "unsubscribe kernelnewbies" to ecartis@xxxxxxxxxxxx Please read the FAQ at http://kernelnewbies.org/FAQ
