Re: [WTF?] sys_tas() on m32r

[liyu]

Al Viro åé:

> asmlinkage int sys_tas(int *addr)
> {
>        int oldval;
>        unsigned long flags;
>
>        if (!access_ok(VERIFY_WRITE, addr, sizeof (int)))
>                return -EFAULT;
>        local_irq_save(flags);
>        oldval = *addr;
>        if (!oldval)
>                *addr = 1;
>        local_irq_restore(flags);
>        return oldval;
> }
> in arch/m32r/kernel/sys_m32r.c.  Trivial oops *AND* ability to trigger
> IO with interrupts disabled.
> -
> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
> the body of a message to majordomo@xxxxxxxxxxxxxxx
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
> Please read the FAQ at  http://www.tux.org/lkml/
>
>
>  
The memory that parameter addr pointer is in user-space.
To access these memory, you should use function like copy_from_user().

-liyu




-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/