From 336ca57c3b4e2b58ea3273e6d978ab3dfa387b4c Mon Sep 17 00:00:00 2001 From: "Eric W. Biederman" Date: Wed, 13 May 2009 16:57:25 +0000 Subject: net-sysfs: Use rtnl_trylock in sysfs methods. The earlier patch to fix the deadlock between a network device going away and writing to sysfs attributes was incomplete. - It did not set signal_pending so we would leak ERSTARTSYS to user space. - It used ERESTARTSYS which only restarts if sigaction configures it to. - It did not cover store and show for ifalias. So fix all of these up and use the new helper restart_syscall so we get the details correct on what it takes. Signed-off-by: Eric W. Biederman Signed-off-by: David S. Miller --- net/core/net-sysfs.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) (limited to 'net/core/net-sysfs.c') diff --git a/net/core/net-sysfs.c b/net/core/net-sysfs.c index 2da59a0ac4a..b9641e816ee 100644 --- a/net/core/net-sysfs.c +++ b/net/core/net-sysfs.c @@ -78,7 +78,7 @@ static ssize_t netdev_store(struct device *dev, struct device_attribute *attr, goto err; if (!rtnl_trylock()) - return -ERESTARTSYS; + return restart_syscall(); if (dev_isalive(net)) { if ((ret = (*set)(net, new)) == 0) @@ -225,7 +225,8 @@ static ssize_t store_ifalias(struct device *dev, struct device_attribute *attr, if (len > 0 && buf[len - 1] == '\n') --count; - rtnl_lock(); + if (!rtnl_trylock()) + return restart_syscall(); ret = dev_set_alias(netdev, buf, count); rtnl_unlock(); @@ -238,7 +239,8 @@ static ssize_t show_ifalias(struct device *dev, const struct net_device *netdev = to_net_dev(dev); ssize_t ret = 0; - rtnl_lock(); + if (!rtnl_trylock()) + return restart_syscall(); if (netdev->ifalias) ret = sprintf(buf, "%s\n", netdev->ifalias); rtnl_unlock(); -- cgit v1.2.3-70-g09d2 From 2b0cc7f78ba55e831c16fb8cb5c204d9d2ecc398 Mon Sep 17 00:00:00 2001 From: "David S. Miller" Date: Tue, 26 May 2009 21:05:19 -0700 Subject: net: Remove bogus reference to BUS_ID_SIZE in sysfs code. BUS_ID_SIZE is really no more, and device names are dynamically allocated and thus can be any necessary size. So remove the BUG check here making sure BUS_ID_SIZE is at least as large as IFNAMSIZ. Signed-off-by: David S. Miller --- net/core/net-sysfs.c | 1 - 1 file changed, 1 deletion(-) (limited to 'net/core/net-sysfs.c') diff --git a/net/core/net-sysfs.c b/net/core/net-sysfs.c index b9641e816ee..3994680c08b 100644 --- a/net/core/net-sysfs.c +++ b/net/core/net-sysfs.c @@ -499,7 +499,6 @@ int netdev_register_kobject(struct net_device *net) dev->platform_data = net; dev->groups = groups; - BUILD_BUG_ON(BUS_ID_SIZE < IFNAMSIZ); dev_set_name(dev, "%s", net->name); #ifdef CONFIG_SYSFS -- cgit v1.2.3-70-g09d2