On Wed, Oct 27, 2004 at 03:36:19PM +0100, Jon Masters wrote:
> On Wed, 27 Oct 2004 15:02:18 +0200, Tommaso Moroni
> <tommaso.m@xxxxxxxxxxxxx> wrote:
>
> > I'm writing a kernel module which, given a struct scsi_cmnd, processes the
> > data involved in the command. If use_sg is 0, I access the data with buffer and
> > bufflen.
>
> Is it possible to post an excerpt from your code in order to help
> understand what you want to do?
Sure!
First of all, the aim is to produce a trace of read and write access to flash drives used
via usb-storage. So in drivers/usb/storage/usb.c I've added a call to a function in the
module I'm writing:
[snip]
/* we've got a command, let's do it! */
else {
US_DEBUG(usb_stor_show_command(us->srb));
if (write_trace_entry)
(* write_trace_entry) (us->srb);
us->proto_handler(us->srb, us);
}
[snip]
In my module when tracing is active write_trace_entry points to real_write_trace_entry:
void real_write_trace_entry(struct scsi_cmnd *cmd)
{
[snip]
if (cmd->use_sg == 0)
data = Byte2StringHex(cmd->buffer, cmd->bufflen);
else
/* here's the problem */
[snip]
where Byte2StringHex converts the data into a hex string.
My problem is how to find the data to parse when cmd->use_sg != 0.
I hope this will clarify the things!
Thank you for the patience,
Tommaso
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