Hi Ben,
On Thu, 14 Feb 2008 07:42:54 +1100, Benjamin Herrenschmidt wrote:
>
> On Wed, 2008-02-13 at 18:35 +0100, Christian Krafft wrote:
> > sensors_detect crashes kernel on PowerPC, as it pokes directly to memory.
For the records, sensors-detect accesses I/O ports, not memory.
> > This patch adds a check_legacy_ioports to read_port and write_port.
> > It will now return ENXIO, instead of oopsing.
> >
> > Signed-off-by: Christian Krafft <[EMAIL PROTECTED]>
>
> The problem is that this prevents using /proc/ioports to access PCI
> IO space, which might be useful.
Maybe Christian's patch can be improved to not do the check on these?
As long as /dev/port exists, it seems reasonable that the kernel should
behave, no matter what I/O ports are accessed from user-space.
> I hate that sensors_detect.. or for that matter any other userland code
> that pokes random ports like that. It should die.
What do you propose as a replacement?
And how is userland code poking at random ports different from kernel
code poking at random ports? We could move sensors-detect inside the
kernel (and I have some plan to do that) but I fail to see how this
would solve this particular problem.
> > Index: linux.git/drivers/char/mem.c
> > ===================================================================
> > --- linux.git.orig/drivers/char/mem.c
> > +++ linux.git/drivers/char/mem.c
> > @@ -566,8 +566,13 @@ static ssize_t read_port(struct file * f
> > char __user *tmp = buf;
> >
> > if (!access_ok(VERIFY_WRITE, buf, count))
> > - return -EFAULT;
> > + return -EFAULT;
> > +
> > while (count-- > 0 && i < 65536) {
> > +#ifdef CONFIG_PPC_MERGE
> > + if (check_legacy_ioport(i))
> > + return -ENXIO;
> > +#endif
> > if (__put_user(inb(i),tmp) < 0)
> > return -EFAULT;
> > i++;
> > @@ -585,6 +590,7 @@ static ssize_t write_port(struct file *
> >
> > if (!access_ok(VERIFY_READ,buf,count))
> > return -EFAULT;
> > +
> > while (count-- > 0 && i < 65536) {
> > char c;
> > if (__get_user(c, tmp)) {
> > @@ -592,6 +598,10 @@ static ssize_t write_port(struct file *
> > break;
> > return -EFAULT;
> > }
> > +#ifdef CONFIG_PPC_MERGE
> > + if (check_legacy_ioport(i))
> > + return -ENXIO;
> > +#endif
> > outb(c,i);
> > i++;
> > tmp++;
--
Jean Delvare
_______________________________________________
Linuxppc-dev mailing list
Linuxppc-dev@ozlabs.org
https://ozlabs.org/mailman/listinfo/linuxppc-dev
