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* kobject: Don't trigger kobject_uevent(KOBJ_REMOVE) twice.Tetsuo Handa2019-04-011-4/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | syzbot is hitting use-after-free bug in uinput module [1]. This is because kobject_uevent(KOBJ_REMOVE) is called again due to commit 0f4dafc0563c6c49 ("Kobject: auto-cleanup on final unref") after memory allocation fault injection made kobject_uevent(KOBJ_REMOVE) from device_del() from input_unregister_device() fail, while uinput_destroy_device() is expecting that kobject_uevent(KOBJ_REMOVE) is not called after device_del() from input_unregister_device() completed. That commit intended to catch cases where nobody even attempted to send "remove" uevents. But there is no guarantee that an event will ultimately be sent. We are at the point of no return as far as the rest of the kernel is concerned; there are no repeats or do-overs. Also, it is not clear whether some subsystem depends on that commit. If no subsystem depends on that commit, it will be better to remove the state_{add,remove}_uevent_sent logic. But we don't want to risk a regression (in a patch which will be backported) by trying to remove that logic. Therefore, as a first step, let's avoid the use-after-free bug by making sure that kobject_uevent(KOBJ_REMOVE) won't be triggered twice. [1] https://syzkaller.appspot.com/bug?id=8b17c134fe938bbddd75a45afaa9e68af43a362d Reported-by: syzbot <syzbot+f648cfb7e0b52bf7ae32@syzkaller.appspotmail.com> Analyzed-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> Fixes: 0f4dafc0563c6c49 ("Kobject: auto-cleanup on final unref") Cc: Kay Sievers <kay@vrfy.org> Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* kobject: drop newline from msg stringBo YU2019-01-221-3/+3
| | | | | | | | | There is currently a missing terminating newline in non-switch case match when msg == NULL Signed-off-by: Bo YU <tsu.yubo@gmail.com> Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* kobject: to repalce printk with pr_* styleBo YU2019-01-221-3/+2
| | | | | | | | | | Repalce printk with pr_warn in kobject_synth_uevent and replace printk with pr_err in uevent_net_init to make both consistent with other code in kobject_uevent.c Signed-off-by: Bo YU <tsu.yubo@gmail.com> Reviewed-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* kobject: Fix warnings in lib/kobject_uevent.cBo YU2018-11-111-0/+2
| | | | | | | Add a blank after declaration. Signed-off-by: Bo YU <tsu.yubo@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* kobject: drop unnecessary cast "%llu" for u64Bo YU2018-11-111-1/+1
| | | | | | | There is no searon for u64 var cast to unsigned long long type. Signed-off-by: Bo YU <tsu.yubo@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* netns: restrict ueventsChristian Brauner2018-05-011-42/+95
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 07e98962fa77 ("kobject: Send hotplug events in all network namespaces") enabled sending hotplug events into all network namespaces back in 2010. Over time the set of uevents that get sent into all network namespaces has shrunk. We have now reached the point where hotplug events for all devices that carry a namespace tag are filtered according to that namespace. Specifically, they are filtered whenever the namespace tag of the kobject does not match the namespace tag of the netlink socket. Currently, only network devices carry namespace tags (i.e. network namespace tags). Hence, uevents for network devices only show up in the network namespace such devices are created in or moved to. However, any uevent for a kobject that does not have a namespace tag associated with it will not be filtered and we will broadcast it into all network namespaces. This behavior stopped making sense when user namespaces were introduced. This patch simplifies and fixes couple of things: - Split codepath for sending uevents by kobject namespace tags: 1. Untagged kobjects - uevent_net_broadcast_untagged(): Untagged kobjects will be broadcast into all uevent sockets recorded in uevent_sock_list, i.e. into all network namespacs owned by the intial user namespace. 2. Tagged kobjects - uevent_net_broadcast_tagged(): Tagged kobjects will only be broadcast into the network namespace they were tagged with. Handling of tagged kobjects in 2. does not cause any semantic changes. This is just splitting out the filtering logic that was handled by kobj_bcast_filter() before. Handling of untagged kobjects in 1. will cause a semantic change. The reasons why this is needed and ok have been discussed in [1]. Here is a short summary: - Userspace ignores uevents from network namespaces that are not owned by the intial user namespace: Uevents are filtered by userspace in a user namespace because the received uid != 0. Instead the uid associated with the event will be 65534 == "nobody" because the global root uid is not mapped. This means we can safely and without introducing regressions modify the kernel to not send uevents into all network namespaces whose owning user namespace is not the initial user namespace because we know that userspace will ignore the message because of the uid anyway. I have a) verified that is is true for every udev implementation out there b) that this behavior has been present in all udev implementations from the very beginning. - Thundering herd: Broadcasting uevents into all network namespaces introduces significant overhead. All processes that listen to uevents running in non-initial user namespaces will end up responding to uevents that will be meaningless to them. Mainly, because non-initial user namespaces cannot easily manage devices unless they have a privileged host-process helping them out. This means that there will be a thundering herd of activity when there shouldn't be any. - Removing needless overhead/Increasing performance: Currently, the uevent socket for each network namespace is added to the global variable uevent_sock_list. The list itself needs to be protected by a mutex. So everytime a uevent is generated the mutex is taken on the list. The mutex is held *from the creation of the uevent (memory allocation, string creation etc. until all uevent sockets have been handled*. This is aggravated by the fact that for each uevent socket that has listeners the mc_list must be walked as well which means we're talking O(n^2) here. Given that a standard Linux workload usually has quite a lot of network namespaces and - in the face of containers - a lot of user namespaces this quickly becomes a performance problem (see "Thundering herd" above). By just recording uevent sockets of network namespaces that are owned by the initial user namespace we significantly increase performance in this codepath. - Injecting uevents: There's a valid argument that containers might be interested in receiving device events especially if they are delegated to them by a privileged userspace process. One prime example are SR-IOV enabled devices that are explicitly designed to be handed of to other users such as VMs or containers. This use-case can now be correctly handled since commit 692ec06d7c92 ("netns: send uevent messages"). This commit introduced the ability to send uevents from userspace. As such we can let a sufficiently privileged (CAP_SYS_ADMIN in the owning user namespace of the network namespace of the netlink socket) userspace process make a decision what uevents should be sent. This removes the need to blindly broadcast uevents into all user namespaces and provides a performant and safe solution to this problem. - Filtering logic: This patch filters by *owning user namespace of the network namespace a given task resides in* and not by user namespace of the task per se. This means if the user namespace of a given task is unshared but the network namespace is kept and is owned by the initial user namespace a listener that is opening the uevent socket in that network namespace can still listen to uevents. - Fix permission for tagged kobjects: Network devices that are created or moved into a network namespace that is owned by a non-initial user namespace currently are send with INVALID_{G,U}ID in their credentials. This means that all current udev implementations in userspace will ignore the uevent they receive for them. This has lead to weird bugs whereby new devices showing up in such network namespaces were not recognized and did not get IPs assigned etc. This patch adjusts the permission to the appropriate {g,u}id in the respective user namespace. This way udevd is able to correctly handle such devices. - Simplify filtering logic: do_one_broadcast() already ensures that only listeners in mc_list receive uevents that have the same network namespace as the uevent socket itself. So the filtering logic in kobj_bcast_filter is not needed (see [3]). This patch therefore removes kobj_bcast_filter() and replaces netlink_broadcast_filtered() with the simpler netlink_broadcast() everywhere. [1]: https://lkml.org/lkml/2018/4/4/739 [2]: https://lkml.org/lkml/2018/4/26/767 [3]: https://lkml.org/lkml/2018/4/26/738 Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* uevent: add alloc_uevent_skb() helperChristian Brauner2018-05-011-13/+34
| | | | | | | This patch adds alloc_uevent_skb() in preparation for follow up patches. Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* net: Drop pernet_operations::asyncKirill Tkhai2018-03-271-1/+0
| | | | | | | | Synchronous pernet_operations are not allowed anymore. All are asynchronous. So, drop the structure member. Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* netns: send uevent messagesChristian Brauner2018-03-221-1/+78
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch adds a receive method to NETLINK_KOBJECT_UEVENT netlink sockets to allow sending uevent messages into the network namespace the socket belongs to. Currently non-initial network namespaces are already isolated and don't receive uevents. There are a number of cases where it is beneficial for a sufficiently privileged userspace process to send a uevent into a network namespace. One such use case would be debugging and fuzzing of a piece of software which listens and reacts to uevents. By running a copy of that software inside a network namespace, specific uevents could then be presented to it. More concretely, this would allow for easy testing of udevd/ueventd. This will also allow some piece of software to run components inside a separate network namespace and then effectively filter what that software can receive. Some examples of software that do directly listen to uevents and that we have in the past attempted to run inside a network namespace are rbd (CEPH client) or the X server. Implementation: The implementation has been kept as simple as possible from the kernel's perspective. Specifically, a simple input method uevent_net_rcv() is added to NETLINK_KOBJECT_UEVENT sockets which completely reuses existing af_netlink infrastructure and does neither add an additional netlink family nor requires any user-visible changes. For example, by using netlink_rcv_skb() we can make use of existing netlink infrastructure to report back informative error messages to userspace. Furthermore, this implementation does not introduce any overhead for existing uevent generating codepaths. The struct netns got a new uevent socket member that records the uevent socket associated with that network namespace including its position in the uevent socket list. Since we record the uevent socket for each network namespace in struct net we don't have to walk the whole uevent socket list. Instead we can directly retrieve the relevant uevent socket and send the message. At exit time we can now also trivially remove the uevent socket from the uevent socket list. This keeps the codepath very performant without introducing needless overhead and even makes older codepaths faster. Uevent sequence numbers are kept global. When a uevent message is sent to another network namespace the implementation will simply increment the global uevent sequence number and append it to the received uevent. This has the advantage that the kernel will never need to parse the received uevent message to replace any existing uevent sequence numbers. Instead it is up to the userspace process to remove any existing uevent sequence numbers in case the uevent message to be sent contains any. Security: In order for a caller to send uevent messages to a target network namespace the caller must have CAP_SYS_ADMIN in the owning user namespace of the target network namespace. Additionally, any received uevent message is verified to not exceed size UEVENT_BUFFER_SIZE. This includes the space needed to append the uevent sequence number. Testing: This patch has been tested and verified to work with the following udev implementations: 1. CentOS 6 with udevd version 147 2. Debian Sid with systemd-udevd version 237 3. Android 7.1.1 with ueventd Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* net: add uevent socket memberChristian Brauner2018-03-221-10/+7
| | | | | | | | | | | | | This commit adds struct uevent_sock to struct net. Since struct uevent_sock records the position of the uevent socket in the uevent socket list we can trivially remove it from the uevent socket list during cleanup. This speeds up the old removal codepath. Note, list_del() will hit __list_del_entry_valid() in its call chain which will validate that the element is a member of the list. If it isn't it will take care that the list is not modified. Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* net: Convert uevent_net_opsKirill Tkhai2018-02-131-0/+1
| | | | | | | | | | | | | | | | uevent_net_init() and uevent_net_exit() create and destroy netlink socket, and these actions serialized in netlink code. Parallel execution with other pernet_operations makes the socket disappear earlier from uevent_sock_list on ->exit. As userspace can't be interested in broadcast messages of dying net, and, as I see, no one in kernel listen them, we may safely make uevent_net_ops async. Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com> Acked-by: Andrei Vagin <avagin@virtuozzo.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* Merge 4.15-rc6 into driver-core-nextGreg Kroah-Hartman2018-01-021-4/+12
|\ | | | | | | | | | | We want the fixes in here as well. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * kobject: fix suppressing modalias in uevents delivered over netlinkDmitry Torokhov2017-12-211-4/+12
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The commit 4a336a23d619 ("kobject: copy env blob in one go") optimized constructing uevent data for delivery over netlink by using the raw environment buffer, instead of reconstructing it from individual environment pointers. Unfortunately in doing so it broke suppressing MODALIAS attribute for KOBJ_UNBIND events, as the code that suppressed this attribute only adjusted the environment pointers, but left the buffer itself alone. Let's fix it by making sure the offending attribute is obliterated form the buffer as well. Reported-by: Tariq Toukan <tariqt@mellanox.com> Reported-by: Casey Leedom <leedom@chelsio.com> Fixes: 4a336a23d619 ("kobject: copy env blob in one go") Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | kobject: Remove redundant license textGreg Kroah-Hartman2017-12-071-2/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Now that the SPDX tag is in all kobject files, that identifies the license in a specific and legally-defined manner. So the extra GPL text wording can be removed as it is no longer needed at all. This is done on a quest to remove the 700+ different ways that files in the kernel describe the GPL license text. And there's unneeded stuff like the address (sometimes incorrect) for the FSF which is never needed. No copyright headers or other non-license-description text was removed. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | kobject: add SPDX identifiers to all kobject filesGreg Kroah-Hartman2017-12-071-0/+1
|/ | | | | | | | | | | | | | | | | | It's good to have SPDX identifiers in all files to make it easier to audit the kernel tree for correct licenses. Update the kobject files files with the correct SPDX license identifier based on the license text in the file itself. The SPDX identifier is a legally binding shorthand, which can be used instead of the full boiler plate text. This work is based on a script and data from Thomas Gleixner, Philippe Ombredanne, and Kate Stewart. Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Kate Stewart <kstewart@linuxfoundation.org> Cc: Philippe Ombredanne <pombredanne@nexb.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller2017-10-051-8/+41
|\ | | | | | | | | | | Just simple overlapping changes. Signed-off-by: David S. Miller <davem@davemloft.net>
| * driver core: suppress sending MODALIAS in UNBIND ueventsDmitry Torokhov2017-09-181-8/+41
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The current udev rules cause modules to be loaded on all device events save for "remove". With the introduction of KOBJ_BIND/KOBJ_UNBIND this causes issues, as driver modules that have devices bound to their drivers get immediately reloaded, and it appears to the user that module unloading doe snot work. The standard udev matching rule is foillowing: ENV{MODALIAS}=="?*", RUN{builtin}+="kmod load $env{MODALIAS}" Given that MODALIAS data is not terribly useful for UNBIND event, let's zap it from the generated uevent environment until we get userspace updated with the correct udev rule that only loads modules on "add" event. Reported-by: Jakub Kicinski <kubakici@wp.pl> Tested-by: Jakub Kicinski <kubakici@wp.pl> Fixes: 1455cf8dbfd0 ("driver core: emit uevents when device is bound ...") Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | kobject: factorize skb setup in kobject_uevent_net_broadcast()Eric Dumazet2017-09-191-15/+19
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | We can build one skb and let it be cloned in netlink. This is much faster, and use less memory (all clones will share the same skb->head) Tested: time perf record (for f in `seq 1 3000` ; do ip netns add tast$f; done) [ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 4.110 MB perf.data (~179584 samples) ] real 0m24.227s # instead of 0m52.554s user 0m0.329s sys 0m23.753s # instead of 0m51.375s 14.77% ip [kernel.kallsyms] [k] __ip6addrlbl_add 14.56% ip [kernel.kallsyms] [k] netlink_broadcast_filtered 11.65% ip [kernel.kallsyms] [k] netlink_has_listeners 6.19% ip [kernel.kallsyms] [k] _raw_spin_lock_irqsave 5.66% ip [kernel.kallsyms] [k] kobject_uevent_env 4.97% ip [kernel.kallsyms] [k] memset_erms 4.67% ip [kernel.kallsyms] [k] refcount_sub_and_test 4.41% ip [kernel.kallsyms] [k] _raw_read_lock 3.59% ip [kernel.kallsyms] [k] refcount_inc_not_zero 3.13% ip [kernel.kallsyms] [k] _raw_spin_unlock_irqrestore 1.55% ip [kernel.kallsyms] [k] __wake_up 1.20% ip [kernel.kallsyms] [k] strlen 1.03% ip [kernel.kallsyms] [k] __wake_up_common 0.93% ip [kernel.kallsyms] [k] consume_skb 0.92% ip [kernel.kallsyms] [k] netlink_trim 0.87% ip [kernel.kallsyms] [k] insert_header 0.63% ip [kernel.kallsyms] [k] unmap_page_range Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | kobject: copy env blob in one goEric Dumazet2017-09-191-7/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | No need to iterate over strings, just copy in one efficient memcpy() call. Tested: time perf record "(for f in `seq 1 3000` ; do ip netns add tast$f; done)" [ perf record: Woken up 10 times to write data ] [ perf record: Captured and wrote 8.224 MB perf.data (~359301 samples) ] real 0m52.554s # instead of 1m7.492s user 0m0.309s sys 0m51.375s # instead of 1m6.875s 9.88% ip [kernel.kallsyms] [k] netlink_broadcast_filtered 8.86% ip [kernel.kallsyms] [k] string 7.37% ip [kernel.kallsyms] [k] __ip6addrlbl_add 5.68% ip [kernel.kallsyms] [k] netlink_has_listeners 5.52% ip [kernel.kallsyms] [k] memcpy_erms 4.76% ip [kernel.kallsyms] [k] __alloc_skb 4.54% ip [kernel.kallsyms] [k] vsnprintf 3.94% ip [kernel.kallsyms] [k] format_decode 3.80% ip [kernel.kallsyms] [k] kmem_cache_alloc_node_trace 3.71% ip [kernel.kallsyms] [k] kmem_cache_alloc_node 3.66% ip [kernel.kallsyms] [k] kobject_uevent_env 3.38% ip [kernel.kallsyms] [k] strlen 2.65% ip [kernel.kallsyms] [k] _raw_spin_lock_irqsave 2.20% ip [kernel.kallsyms] [k] kfree 2.09% ip [kernel.kallsyms] [k] memset_erms 2.07% ip [kernel.kallsyms] [k] ___cache_free 1.95% ip [kernel.kallsyms] [k] kmem_cache_free 1.91% ip [kernel.kallsyms] [k] _raw_read_lock 1.45% ip [kernel.kallsyms] [k] ksize 1.25% ip [kernel.kallsyms] [k] _raw_spin_unlock_irqrestore 1.00% ip [kernel.kallsyms] [k] widen_string Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | kobject: add kobject_uevent_net_broadcast()Eric Dumazet2017-09-191-43/+53
|/ | | | | | | This removes some #ifdef pollution and will ease follow up patches. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* Merge branch 'bind_unbind' into driver-core-nextGreg Kroah-Hartman2017-07-221-0/+2
|\ | | | | | | | | | | | | | | This merges the bind_unbind driver core feature into the driver-core-next branch. bind_unbind is a branch so that others can pull and work off of it safely. Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| * driver core: emit uevents when device is bound to a driverDmitry Torokhov2017-07-221-0/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | There are certain touch controllers that may come up in either normal (application) or boot mode, depending on whether firmware/configuration is corrupted when they are powered on. In boot mode the kernel does not create input device instance (because it does not necessarily know the characteristics of the input device in question). Another number of controllers does not store firmware in a non-volatile memory, and they similarly need to have firmware loaded before input device instance is created. There are also other types of devices with similar behavior. There is a desire to be able to trigger firmware loading via udev, but it has to happen only when driver is bound to a physical device (i2c or spi). These udev actions can not use ADD events, as those happen too early, so we are introducing BIND and UNBIND events that are emitted at the right moment. Also, many drivers create additional driver-specific device attributes when binding to the device, to provide userspace with additional controls. The new events allow userspace to adjust these driver-specific attributes without worrying that they are not there yet. Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* | kobject: support passing in variables for synthetic ueventsPeter Rajnoha2017-05-251-13/+154
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch makes it possible to pass additional arguments in addition to uevent action name when writing /sys/.../uevent attribute. These additional arguments are then inserted into generated synthetic uevent as additional environment variables. Before, we were not able to pass any additional uevent environment variables for synthetic uevents. This made it hard to identify such uevents properly in userspace to make proper distinction between genuine uevents originating from kernel and synthetic uevents triggered from userspace. Also, it was not possible to pass any additional information which would make it possible to optimize and change the way the synthetic uevents are processed back in userspace based on the originating environment of the triggering action in userspace. With the extra additional variables, we are able to pass through this extra information needed and also it makes it possible to synchronize with such synthetic uevents as they can be clearly identified back in userspace. The format for writing the uevent attribute is following: ACTION [UUID [KEY=VALUE ...] There's no change in how "ACTION" is recognized - it stays the same ("add", "change", "remove"). The "ACTION" is the only argument required to generate synthetic uevent, the rest of arguments, that this patch adds support for, are optional. The "UUID" is considered as transaction identifier so it's possible to use the same UUID value for one or more synthetic uevents in which case we logically group these uevents together for any userspace listeners. The "UUID" is expected to be in "xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx" format where "x" is a hex digit. The value appears in uevent as "SYNTH_UUID=xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx" environment variable. The "KEY=VALUE" pairs can contain alphanumeric characters only. It's possible to define zero or more more pairs - each pair is then delimited by a space character " ". Each pair appears in synthetic uevents as "SYNTH_ARG_KEY=VALUE" environment variable. That means the KEY name gains "SYNTH_ARG_" prefix to avoid possible collisions with existing variables. To pass the "KEY=VALUE" pairs, it's also required to pass in the "UUID" part for the synthetic uevent first. If "UUID" is not passed in, the generated synthetic uevent gains "SYNTH_UUID=0" environment variable automatically so it's possible to identify this situation in userspace when reading generated uevent and so we can still make a difference between genuine and synthetic uevents. Signed-off-by: Peter Rajnoha <prajnoha@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* kobject: improve function-level documentationJulia Lawall2016-10-281-3/+3
| | | | | | | | | | | | | In the first case, rename the second variable to correspond to the name found in the function parameter list. In the remaining cases, reorder the variables to correspond to their order in the parameter list. Issue detected using Coccinelle (http://coccinelle.lip6.fr/) Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* lib/kobject_uevent.c: remove redundant includeRasmus Villemoes2015-02-121-1/+0
| | | | | | | | | | The file doesn't seem to use anything from linux/user_namespace.h, and removing it yields byte-identical object code and strictly fewer dependencies in the .cmd file. Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* kobject: Make support for uevent_helper optional.Michael Marineau2014-04-251-0/+6
| | | | | | | | | Support for uevent_helper, aka hotplug, is not required on many systems these days but it can still be enabled via sysfs or sysctl. Reported-by: Darren Shepherd <darren.s.shepherd@gmail.com> Signed-off-by: Michael Marineau <mike@marineau.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* kobject: don't block for each kobject_ueventVladimir Davydov2014-04-031-6/+36
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently kobject_uevent has somewhat unpredictable semantics. The point is, since it may call a usermode helper and wait for it to execute (UMH_WAIT_EXEC), it is impossible to say for sure what lock dependencies it will introduce for the caller - strictly speaking it depends on what fs the binary is located on and the set of locks fork may take. There are quite a few kobject_uevent's users that do not take this into account and call it with various mutexes taken, e.g. rtnl_mutex, net_mutex, which might potentially lead to a deadlock. Since there is actually no reason to wait for the usermode helper to execute there, let's make kobject_uevent start the helper asynchronously with the aid of the UMH_NO_WAIT flag. Personally, I'm interested in this, because I really want kobject_uevent to be called under the slab_mutex in the slub implementation as it used to be some time ago, because it greatly simplifies synchronization and automatically fixes a kmemcg-related race. However, there was a deadlock detected on an attempt to call kobject_uevent under the slab_mutex (see https://lkml.org/lkml/2012/1/14/45), which was reported to be fixed by releasing the slab_mutex for kobject_uevent. Unfortunately, there was no information about who exactly blocked on the slab_mutex causing the usermode helper to stall, neither have I managed to find this out or reproduce the issue. BTW, this is not the first attempt to make kobject_uevent use UMH_NO_WAIT. Previous one was made by commit f520360d93cd ("kobject: don't block for each kobject_uevent"), but it was wrong (it passed arguments allocated on stack to async thread) so it was reverted in 05f54c13cd0c ("Revert "kobject: don't block for each kobject_uevent"."). It targeted on speeding up the boot process though. Signed-off-by: Vladimir Davydov <vdavydov@parallels.com> Cc: Greg KH <greg@kroah.com> Cc: Christoph Lameter <cl@linux.com> Cc: Pekka Enberg <penberg@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* net: fix "queues" uevent between network namespacesWeilong Chen2014-01-191-2/+8
| | | | | | | | | | | | | | When I create a new namespace with 'ip netns add net0', or add/remove new links in a namespace with 'ip link add/delete type veth', rx/tx queues events can be got in all namespaces. That is because rx/tx queue ktypes do not have namespace support, and their kobj parents are setted to NULL. This patch is to fix it. Reported-by: Libo Chen <chenlibo@huawei.com> Signed-off-by: Libo Chen <chenlibo@huawei.com> Signed-off-by: Weilong Chen <chenweilong@huawei.com> Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* netlink: hide struct module parameter in netlink_kernel_createPablo Neira Ayuso2012-09-081-2/+1
| | | | | | | | | | | This patch defines netlink_kernel_create as a wrapper function of __netlink_kernel_create to hide the struct module *me parameter (which seems to be THIS_MODULE in all existing netlink subsystems). Suggested by David S. Miller. Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* netlink: kill netlink_set_nonrootPablo Neira Ayuso2012-09-081-1/+1
| | | | | | | | | | | | | | | Replace netlink_set_nonroot by one new field `flags' in struct netlink_kernel_cfg that is passed to netlink_kernel_create. This patch also renames NL_NONROOT_* to NL_CFG_F_NONROOT_* since now the flags field in nl_table is generic (so we can add more flags if needed in the future). Also adjust all callers in the net-next tree to use these flags instead of netlink_set_nonroot. Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* netlink: add netlink_kernel_cfg parameter to netlink_kernel_createPablo Neira Ayuso2012-06-291-1/+4
| | | | | | | | | | | | | | | | | | | | | | | | | This patch adds the following structure: struct netlink_kernel_cfg { unsigned int groups; void (*input)(struct sk_buff *skb); struct mutex *cb_mutex; }; That can be passed to netlink_kernel_create to set optional configurations for netlink kernel sockets. I've populated this structure by looking for NULL and zero parameters at the existing code. The remaining parameters that always need to be set are still left in the original interface. That includes optional parameters for the netlink socket creation. This allows easy extensibility of this interface in the future. This patch also adapts all callers to use this new interface. Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: David S. Miller <davem@davemloft.net>
* Merge tag 'module-for-3.4' of ↵Linus Torvalds2012-03-241-1/+2
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux Pull cleanup of fs/ and lib/ users of module.h from Paul Gortmaker: "Fix up files in fs/ and lib/ dirs to only use module.h if they really need it. These are trivial in scope vs the work done previously. We now have things where any few remaining cleanups can be farmed out to arch or subsystem maintainers, and I have done so when possible. What is remaining here represents the bits that don't clearly lie within a single arch/subsystem boundary, like the fs dir and the lib dir. Some duplicate includes arising from overlapping fixes from independent subsystem maintainer submissions are also quashed." Fix up trivial conflicts due to clashes with other include file cleanups (including some due to the previous bug.h cleanup pull). * tag 'module-for-3.4' of git://git.kernel.org/pub/scm/linux/kernel/git/paulg/linux: lib: reduce the use of module.h wherever possible fs: reduce the use of module.h wherever possible includecheck: delete any duplicate instances of module.h
| * lib: reduce the use of module.h wherever possiblePaul Gortmaker2012-03-071-1/+2
| | | | | | | | | | | | | | | | | | | | For files only using THIS_MODULE and/or EXPORT_SYMBOL, map them onto including export.h -- or if the file isn't even using those, then just delete the include. Fix up any implicit include dependencies that were being masked by module.h along the way. Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
* | uevent: send events in correct order according to seqnum (v3)Andrew Vagin2012-03-081-10/+9
|/ | | | | | | | | | | | | | | | | | | | | The queue handling in the udev daemon assumes that the events are ordered. Before this patch uevent_seqnum is incremented under sequence_lock, than an event is send uner uevent_sock_mutex. I want to say that code contained a window between incrementing seqnum and sending an event. This patch locks uevent_sock_mutex before incrementing uevent_seqnum. v2: delete sequence_lock, uevent_seqnum is protected by uevent_sock_mutex v3: unlock the mutex before the goto exit Thanks for Kay for the comments. Signed-off-by: Andrew Vagin <avagin@openvz.org> Tested-By: Kay Sievers <kay.sievers@vrfy.org> Cc: stable <stable@vger.kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* driver-core: skip uevent generation when nobody is listeningKay Sievers2011-12-091-0/+3
| | | | | | | | | Most network namespaces unlikely have listeners to uevents, and should benefit from skipping all the string copies. Cc: Eric Biederman <ebiederm@xmission.com> Signed-off-by: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* kobj_uevent: Ignore if some listeners cannot handle messageMilan Broz2011-08-221-1/+1
| | | | | | | | | | | | | | | | kobject_uevent() uses a multicast socket and should ignore if one of listeners cannot handle messages or nobody is listening at all. Easily reproducible when a process in system is cloned with CLONE_NEWNET flag. (See also http://article.gmane.org/gmane.linux.kernel.device-mapper.dm-crypt/5256) Signed-off-by: Milan Broz <mbroz@redhat.com> Acked-by: Kay Sievers <kay.sievers@vrfy.org> Cc: stable <stable@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* kobject_uevent: fix typo in commentsXiaotian Feng2010-08-231-2/+2
| | | | | | | | s/ending/sending, s/kobject_uevent()/kobject_uevent_env() in the comments. Signed-off-by: Xiaotian Feng <xtfeng@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* kobject: free memory if netlink_kernel_create() failsDan Carpenter2010-06-041-0/+1
| | | | | | | | | | There is a kfree(ue_sk) missing on the error path if netlink_kernel_create() fails. Signed-off-by: Dan Carpenter <error27@gmail.com> Reviewed-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* lib/kobject_uevent.c: fix CONIG_NET=n warningAndrew Morton2010-06-041-0/+2
| | | | | | | | | | | | lib/kobject_uevent.c:87: warning: 'kobj_bcast_filter' defined but not used Repairs "hotplug: netns aware uevent_helper" Cc: Eric W. Biederman <ebiederm@xmission.com> Cc: David S. Miller <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* hotplug: netns aware uevent_helperEric W. Biederman2010-05-211-2/+17
| | | | | | | | | | | | It only makes sense for uevent_helper to get events in the intial namespaces. It's invocation is not per namespace and it is not clear how we could make it's invocation namespace aware. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Acked-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* kobj: Send hotplug events in the proper namespace.Eric W. Biederman2010-05-211-2/+20
| | | | | | | | | | Utilize netlink_broacast_filtered to allow sending hotplug events in the proper namespace. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Acked-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* kobject: Send hotplug events in all network namespacesEric W. Biederman2010-05-211-8/+60
| | | | | | | | | | Open a copy of the uevent kernel socket in each network namespace so we can send uevents in all network namespaces. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Acked-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* include cleanup: Update gfp.h and slab.h includes to prepare for breaking ↵Tejun Heo2010-03-301-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | implicit slab.h inclusion from percpu.h percpu.h is included by sched.h and module.h and thus ends up being included when building most .c files. percpu.h includes slab.h which in turn includes gfp.h making everything defined by the two files universally available and complicating inclusion dependencies. percpu.h -> slab.h dependency is about to be removed. Prepare for this change by updating users of gfp and slab facilities include those headers directly instead of assuming availability. As this conversion needs to touch large number of source files, the following script is used as the basis of conversion. http://userweb.kernel.org/~tj/misc/slabh-sweep.py The script does the followings. * Scan files for gfp and slab usages and update includes such that only the necessary includes are there. ie. if only gfp is used, gfp.h, if slab is used, slab.h. * When the script inserts a new include, it looks at the include blocks and try to put the new include such that its order conforms to its surrounding. It's put in the include block which contains core kernel includes, in the same order that the rest are ordered - alphabetical, Christmas tree, rev-Xmas-tree or at the end if there doesn't seem to be any matching order. * If the script can't find a place to put a new include (mostly because the file doesn't have fitting include block), it prints out an error message indicating which .h file needs to be added to the file. The conversion was done in the following steps. 1. The initial automatic conversion of all .c files updated slightly over 4000 files, deleting around 700 includes and adding ~480 gfp.h and ~3000 slab.h inclusions. The script emitted errors for ~400 files. 2. Each error was manually checked. Some didn't need the inclusion, some needed manual addition while adding it to implementation .h or embedding .c file was more appropriate for others. This step added inclusions to around 150 files. 3. The script was run again and the output was compared to the edits from #2 to make sure no file was left behind. 4. Several build tests were done and a couple of problems were fixed. e.g. lib/decompress_*.c used malloc/free() wrappers around slab APIs requiring slab.h to be added manually. 5. The script was run on all .h files but without automatically editing them as sprinkling gfp.h and slab.h inclusions around .h files could easily lead to inclusion dependency hell. Most gfp.h inclusion directives were ignored as stuff from gfp.h was usually wildly available and often used in preprocessor macros. Each slab.h inclusion directive was examined and added manually as necessary. 6. percpu.h was updated not to include slab.h. 7. Build test were done on the following configurations and failures were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my distributed build env didn't work with gcov compiles) and a few more options had to be turned off depending on archs to make things build (like ipr on powerpc/64 which failed due to missing writeq). * x86 and x86_64 UP and SMP allmodconfig and a custom test config. * powerpc and powerpc64 SMP allmodconfig * sparc and sparc64 SMP allmodconfig * ia64 SMP allmodconfig * s390 SMP allmodconfig * alpha SMP allmodconfig * um on x86_64 SMP allmodconfig 8. percpu.h modifications were reverted so that it could be applied as a separate patch and serve as bisection point. Given the fact that I had only a couple of failures from tests on step 6, I'm fairly confident about the coverage of this conversion patch. If there is a breakage, it's likely to be something in one of the arch headers which should be easily discoverable easily on most builds of the specific arch. Signed-off-by: Tejun Heo <tj@kernel.org> Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org> Cc: Ingo Molnar <mingo@redhat.com> Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
* kobject: Constify struct kset_uevent_opsEmese Revfy2010-03-071-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | Constify struct kset_uevent_ops. This is part of the ops structure constification effort started by Arjan van de Ven et al. Benefits of this constification: * prevents modification of data that is shared (referenced) by many other structure instances at runtime * detects/prevents accidental (but not intentional) modification attempts on archs that enforce read-only kernel data at runtime * potentially better optimized code as the compiler can assume that the const data cannot be changed * the compiler/linker move const data into .rodata and therefore exclude them from false sharing Signed-off-by: Emese Revfy <re.emese@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* driver core: allow non-root users to listen to ueventsKay Sievers2009-04-161-1/+1
| | | | | | | | | | Users can read sysfs files, there is no reason they should not be allowed to listen to uevents. This lets xorg and other userspace programs properly get these messages without having to be root. Signed-off-by: Kay Sievers <kay.sievers@vrfy.org> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* Revert "kobject: don't block for each kobject_uevent".Hugh Dickins2009-04-161-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | This reverts commit f520360d93cdc37de5d972dac4bf3bdef6a7f6a7. Tetsuo Handa, running a kernel with CONFIG_DEBUG_PAGEALLOC=y and CONFIG_UEVENT_HELPER_PATH=/sbin/hotplug, has been hitting RCU detected CPU stalls: it's been spinning in the loop where do_execve() counts up the args (but why wasn't fixup_exception working? dunno). The recent change, switching kobject_uevent_env() from UMH_WAIT_EXEC to UMH_NO_WAIT, is broken: the exec uses args on the local stack here, and an env which is kfreed as soon as call_usermodehelper() returns. It very much needs to wait for the exec to be done. An alternative would be to keep the UMH_NO_WAIT, and complicate the code to allocate and free these resources correctly? but no, as GregKH pointed out when making the commit, CONFIG_UEVENT_HELPER_PATH="" is a much better optimization - though some distros are still saying /sbin/hotplug in their .config, yet with no such binary in their initrd or their root. Reported-by: Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp> Signed-off-by: Hugh Dickins <hugh@veritas.com> Acked-by: Greg Kroah-Hartman <gregkh@suse.de> Acked-by: Arjan van de Ven <arjan@linux.intel.com> Acked-by: Will Newton <will.newton@gmail.com> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
* Merge branch 'master' of /home/davem/src/GIT/linux-2.6/David S. Miller2009-03-261-1/+8
|\ | | | | | | | | Conflicts: drivers/net/wimax/i2400m/usb-notif.c
| * kobject: don't block for each kobject_ueventArjan van de Ven2009-03-241-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Right now, the kobject_uevent code blocks for each uevent that's being generated, due to using (for hystoric reasons) UHM_WAIT_EXEC as flag to call_usermode_helper(). Specifically, the effect is that each uevent that is being sent causes the code to wake up keventd, then block until keventd has processed the work. Needless to say, this happens many times during the system boot. This patches changes that to UHN_NO_WAIT (brilliant name for a constant btw) so that we only schedule the work to fire the uevent message, but do not wait for keventd to process the work. This removes one of the bottlenecks during boot; each one of them is only a small effect, but the sum of them does add up. [Note, distros that need this are broken, they should be setting CONFIG_UEVENT_HELPER_PATH to "", that way this code path will never be excuted at all -- gregkh] Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
| * Driver core: implement uevent suppress in kobjectMing Lei2009-03-241-0/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch implements uevent suppress in kobject and removes it from struct device, based on the following ideas: 1,Uevent sending should be one attribute of kobject, so suppressing it in kobject layer is more natural than in device layer. By this way, we can do it for other objects embedded with kobject. 2,It may save several bytes for each instance of struct device.(On my omap3(32bit ARM) based box, can save 8bytes per device object) This patch also introduces dev_set|get_uevent_suppress() helpers to set and query uevent_suppress attribute in case to help kobject as private part of struct device in future. [This version is against the latest driver-core patch set of Greg,please ignore the last version.] Signed-off-by: Ming Lei <tom.leiming@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
* | netlink: change return-value logic of netlink_broadcast()Pablo Neira Ayuso2009-02-051-0/+3
|/ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Currently, netlink_broadcast() reports errors to the caller if no messages at all were delivered: 1) If, at least, one message has been delivered correctly, returns 0. 2) Otherwise, if no messages at all were delivered due to skb_clone() failure, return -ENOBUFS. 3) Otherwise, if there are no listeners, return -ESRCH. With this patch, the caller knows if the delivery of any of the messages to the listeners have failed: 1) If it fails to deliver any message (for whatever reason), return -ENOBUFS. 2) Otherwise, if all messages were delivered OK, returns 0. 3) Otherwise, if no listeners, return -ESRCH. In the current ctnetlink code and in Netfilter in general, we can add reliable logging and connection tracking event delivery by dropping the packets whose events were not successfully delivered over Netlink. Of course, this option would be settable via /proc as this approach reduces performance (in terms of filtered connections per seconds by a stateful firewall) but providing reliable logging and event delivery (for conntrackd) in return. This patch also changes some clients of netlink_broadcast() that may report ENOBUFS errors via printk. This error handling is not of any help. Instead, the userspace daemons that are listening to those netlink messages should resync themselves with the kernel-side if they hit ENOBUFS. BTW, netlink_broadcast() clients include those that call cn_netlink_send(), nlmsg_multicast() and genlmsg_multicast() since they internally call netlink_broadcast() and return its error value. Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: David S. Miller <davem@davemloft.net>
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