Hi Rafael.
Probably you haven't got any answers yet because you should NEVER EVER
(i repeat: NEVER EVER, not even in college projects) go for file I/O in
the kernel. You might want to think the whole thing over one or two
times, i think.
If it comes to you that it is absolutely necessary (i repeat again:
ABSOLUTELY NECESSARY, like a solution to feed the world) then you might
google for some ancient FAQ of Greg (K-H) (i think he was) where he
tries to give a little more details about this kind of problem, and also
gives a possible solution, IIRC. Sorry that i don't remember the exact
page/adress anymore, for i intend never to look at it again.
Greetz
Joe
Rafael Sisto schrieb:
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.-
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
--
Sepp "ZaP" Holzmayr
please reply to:
[EMAIL PROTECTED]
watch out for:
www.rocksociety.de
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
