lkml.org 
[lkml]   [2008]   [Jan]   [19]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
Subjectcreate a file in kernel mode. help please!
Hi there,
obviously this is a newbie question, but I couldn't find any
documentation on how to do it.. I tried several ways but couldnt do
it.
I designed a system call, so a user will call it, and a new file will
be created ('/tmp/filexx'). After that, I have another system call,
that will map the file into the maps of the user process. The idea is
the same as IPC...

I managed to create the file with this function (in the first system call):
fd = filp_open(path, O_CREAT | O_RDWR , 777);

After that, the user will call another system call, and it will map
this file to the process maps.
something like this:
filp_open(route, O_RDWR,0 );
do_mmap(fp, 0, tamano, PROT_READ | PROT_WRITE | PROT_EXEC,
MAP_SHARED, 0);

After I call the second system call, the user tries to access the
memory, but gets the message "Bus Error".
I tried to manually create a file with vi, and then use the second
system call, and worked perfectly. I could use the shared memory
without problems.

The problems seems to be in the first system call (with filp_open),
when I try to create a new file... Can somebody suggest me something,
on how I could fix this issue?? It is very important because it is for
a college projects.

Greetings, and thanks in advance for the answers.
Rafael Sisto - Uruguay.-


\
 
 \ /
  Last update: 2008-01-19 06:21    [W:0.089 / U:0.336 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site