Date: Thu, 31 Oct 2002 19:37:19 +0100 From: Hanspeter Roth <hampi@rootshell.be> To: freebsd-hackers@FreeBSD.ORG Subject: Patch to prevent write-protected floppy from being mounted writable Message-ID: <20021031193719.A940@gicco.homeip.net> In-Reply-To: <20021031145952.A457@mezcal.tue.le>; from thz@Lennartz-electronic.de on Thu, Oct 31, 2002 at 02:59:52PM %2B0100 References: <20021029182712.A1479@gicco.homeip.net> <94460.1035912876@critter.freebsd.dk> <20021031145952.A457@mezcal.tue.le>
next in thread | previous in thread | raw e-mail | index | archive | help
On Oct 31 at 14:59, Thomas Zenker spoke:
> On Tue, Oct 29, 2002 at 06:34:36PM +0100, Poul-Henning Kamp wrote:
> > That's a slightly more involved issue because you would have to
> > actually try to write to it before you find out that you can't.
>
> for stable I have a patch, which checks during open for write
> protection of the floppy if FWRITE bit is set and fails with EPERM
> if this is the case. This works reliably for me. The reason I haven't
> sent this patch in is, there is a possible conflict with accesses
> to a second floppy disk drive at the same time. Anyway, better than
> panic'ing the machine...
>
> Actually all accesses to the controller hardware are serialized
> thru a state machine "fdstate". The Bad Thing is, that this state
> machine is bound too tight to the strategy (i.e. you get some job
> done via a buffer or nothing). Best example is the interfacing of
> formatting via the B_FORMAT/B_XXX kludge. The Right Thing would
> be to redesign the interface to the state machine to get jobs done
> from any source (with or without buffer) and maintaining state of
> write protection.
>
> Index: sys/isa/fd.c
> ===================================================================
> RCS file: /usr/cvs/FreeBSD/src/sys/isa/fd.c,v
> retrieving revision 1.176.2.8
> diff -u -r1.176.2.8 fd.c
> --- sys/isa/fd.c 15 May 2002 21:56:14 -0000 1.176.2.8
> +++ sys/isa/fd.c 31 Oct 2002 13:06:05 -0000
> @@ -1448,6 +1448,21 @@
> }
> }
> fd->ft = fd_types + type - 1;
> + if (flags & FWRITE) { /* check for write protection */
> + int r, s, st3;
> + s = splbio();
> + set_motor(fdc, fd->fdsu, TURNON); /* select drive */
> + r = fd_sense_drive_status(fdc, &st3);
> + set_motor(fdc, fd->fdsu, TURNOFF);
> + fdc->state = RESETCTLR;
> + splx(s);
> + if(r != 0)
> + return(ENXIO);
> + if (st3 & NE7_ST3_WP) {
> + device_printf(fd->dev, "write protected\n");
> + return(EPERM);
> + }
> + }
> fd->flags |= FD_OPEN;
> /*
> * Clearing the DMA overrun counter at open time is a bit messy.
>
>
> Cheers,
>
> -- Thomas Zenker
Hey, exactly! Thank you!
Could the core team consider this patch to get merged into 4.8?
-Hanspeter
To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-hackers" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20021031193719.A940>