Re: [PATCH 7/11] 2.6.18-mm3 pktcdvd: make procfs interface optional

[Peter Osterlund <petero2@telia.com>]

"Thomas Maier" <balagi@justmail.de> writes:

> this patch makes the procfs interface optional and groups
> the procfs functions together.
> New kernel config parameter: CDROM_PKTCDVD_PROCINTF

Given the fact that Linus doesn't allow breaking user space tools
unless absolutely necessary, I don't think it makes sense to be able
to disable the character device control code.

The /proc/driver/pktcdvd/pktcdvd? file only contains debugging stuff
though, and the main reason it's not already in debugfs is that
debugfs didn't exist when Jens wrote this driver.

Therefore a patch that unconditionally moves
/proc/driver/pktcdvd/pktcdvd? to debugfs would make a lot of sense.

Also, the current change has another problem:

static int pkt_seq_show(struct seq_file *m, void *p)
+{
+       struct pktcdvd_device *pd = m->private;
+       char buf[1024];
+
+       pkt_print_info(pd, buf, sizeof(buf));
+       seq_printf(m, "%s", buf);
+       return 0;
+}

This wastes 1K stack space, and it can corrupt the stack if the
pkt_print_info() function wants to write more than 1K data.

Unconditionally moving to debugfs would remove the need for the
pkt_print_info() function so the buf array wouldn't be needed any
more.

-- 
Peter Osterlund - petero2@telia.com
http://web.telia.com/~u89404340