From mboxrd@z Thu Jan 1 00:00:00 1970 From: Lennert Buytenhek Date: Wed, 16 Jan 2002 17:46:46 +0000 Subject: Re: [buytenh@gnu.org: [cry for advice] sparc64 bridging troubles] Message-Id: List-Id: References: In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: ultralinux@vger.kernel.org On Fri, Jan 11, 2002 at 12:15:54AM -0800, David S. Miller wrote: > This copy_from_user invocation hangs the box solid, every single time. The > arguments it's called with are fffff8001395f910, 00000000effff9f8, 32. I > would think these look OK (and even if they wouldn't I guess they shouldn't > hang the box). > > If set_fs(KERNEL_DS) this will hang the box because that means that > both pointers need to be kernel points. Whoops, missed that! (I knew it, but didn't realise this could mess things up) > The real solution is to move away from SIOCDEVPRIVATE since those > are deprecated anyways, but you appear to understand this already. > :-) Yup. The attached patch (plus some userspace changes) is what makes things tick again, but it's not exactly a marvel of beauty.. :( Thanks a lot! Lennert --- linux-2.4.17-br-sparc64/net/bridge/br_device.c.orig Wed Jan 16 12:36:28 2002 +++ linux-2.4.17-br-sparc64/net/bridge/br_device.c Wed Jan 16 12:40:22 2002 @@ -23,15 +23,26 @@ { unsigned long args[4]; unsigned long *data; + mm_segment_t oldfs = get_fs(); + int ret; + int retval; - if (cmd != SIOCDEVPRIVATE) + if (cmd != SIOCDEVPRIVATE && cmd != SIOCDEVPRIVATE + 3) return -EOPNOTSUPP; data = (unsigned long *)rq->ifr_data; - if (copy_from_user(args, data, 4*sizeof(unsigned long))) - return -EFAULT; + set_fs(USER_DS); + ret = copy_from_user(args, data, 4*sizeof(unsigned long)); - return br_ioctl(dev->priv, args[0], args[1], args[2], args[3]); + retval = -EFAULT; + if (ret) + goto out; + + retval = br_ioctl(dev->priv, args[0], args[1], args[2], args[3]); + +out: + set_fs(oldfs); + return retval; } static struct net_device_stats *br_dev_get_stats(struct net_device *dev) --- linux-2.4.17-br-sparc64/arch/sparc64/kernel/ioctl32.c.orig Wed Jan 16 12:36:05 2002 +++ linux-2.4.17-br-sparc64/arch/sparc64/kernel/ioctl32.c Wed Jan 16 12:38:07 2002 @@ -472,6 +472,7 @@ return -ENODEV; strcpy(ifr32.ifr_name, dev->name); + dev_put(dev); err = copy_to_user((struct ifreq32 *)arg, &ifr32, sizeof(struct ifreq32)); return (err ? -EFAULT : 0); @@ -4605,6 +4606,7 @@ HANDLE_IOCTL(SIOCGPPPSTATS, dev_ifsioc) HANDLE_IOCTL(SIOCGPPPCSTATS, dev_ifsioc) HANDLE_IOCTL(SIOCGPPPVER, dev_ifsioc) +HANDLE_IOCTL(SIOCDEVPRIVATE + 3, dev_ifsioc) HANDLE_IOCTL(SIOCGIFTXQLEN, dev_ifsioc) HANDLE_IOCTL(SIOCSIFTXQLEN, dev_ifsioc) HANDLE_IOCTL(SIOCETHTOOL, ethtool_ioctl)