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2012-08-21af_netlink: force credentials passing [CVE-2012-3520]Eric Dumazet
Pablo Neira Ayuso discovered that avahi and potentially NetworkManager accept spoofed Netlink messages because of a kernel bug. The kernel passes all-zero SCM_CREDENTIALS ancillary data to the receiver if the sender did not provide such data, instead of not including any such data at all or including the correct data from the peer (as it is the case with AF_UNIX). This bug was introduced in commit 16e572626961 (af_unix: dont send SCM_CREDENTIALS by default) This patch forces passing credentials for netlink, as before the regression. Another fix would be to not add SCM_CREDENTIALS in netlink messages if not provided by the sender, but it might break some programs. With help from Florian Weimer & Petr Matousek This issue is designated as CVE-2012-3520 Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Petr Matousek <pmatouse@redhat.com> Cc: Florian Weimer <fweimer@redhat.com> Cc: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-08-01Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull second vfs pile from Al Viro: "The stuff in there: fsfreeze deadlock fixes by Jan (essentially, the deadlock reproduced by xfstests 068), symlink and hardlink restriction patches, plus assorted cleanups and fixes. Note that another fsfreeze deadlock (emergency thaw one) is *not* dealt with - the series by Fernando conflicts a lot with Jan's, breaks userland ABI (FIFREEZE semantics gets changed) and trades the deadlock for massive vfsmount leak; this is going to be handled next cycle. There probably will be another pull request, but that stuff won't be in it." Fix up trivial conflicts due to unrelated changes next to each other in drivers/{staging/gdm72xx/usb_boot.c, usb/gadget/storage_common.c} * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (54 commits) delousing target_core_file a bit Documentation: Correct s_umount state for freeze_fs/unfreeze_fs fs: Remove old freezing mechanism ext2: Implement freezing btrfs: Convert to new freezing mechanism nilfs2: Convert to new freezing mechanism ntfs: Convert to new freezing mechanism fuse: Convert to new freezing mechanism gfs2: Convert to new freezing mechanism ocfs2: Convert to new freezing mechanism xfs: Convert to new freezing code ext4: Convert to new freezing mechanism fs: Protect write paths by sb_start_write - sb_end_write fs: Skip atime update on frozen filesystem fs: Add freezing handling to mnt_want_write() / mnt_drop_write() fs: Improve filesystem freezing handling switch the protection of percpu_counter list to spinlock nfsd: Push mnt_want_write() outside of i_mutex btrfs: Push mnt_want_write() outside of i_mutex fat: Push mnt_want_write() outside of i_mutex ...
2012-07-29clean unix_bind() up a bitAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-29pull mnt_want_write()/mnt_drop_write() into ↵Al Viro
kern_path_create()/done_path_create() resp. One side effect - attempt to create a cross-device link on a read-only fs fails with EROFS instead of EXDEV now. Makes more sense, POSIX allows, etc. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-29new helper: done_path_create()Al Viro
releases what needs to be released after {kern,user}_path_create() Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-07-16net: make sock diag per-namespaceAndrey Vagin
Before this patch sock_diag works for init_net only and dumps information about sockets from all namespaces. This patch expands sock_diag for all name-spaces. It creates a netlink kernel socket for each netns and filters data during dumping. v2: filter accoding with netns in all places remove an unused variable. Cc: "David S. Miller" <davem@davemloft.net> Cc: Alexey Kuznetsov <kuznet@ms2.inr.ac.ru> Cc: James Morris <jmorris@namei.org> Cc: Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org> Cc: Patrick McHardy <kaber@trash.net> Cc: Pavel Emelyanov <xemul@parallels.com> CC: Eric Dumazet <eric.dumazet@gmail.com> Cc: linux-kernel@vger.kernel.org Cc: netdev@vger.kernel.org Signed-off-by: Andrew Vagin <avagin@openvz.org> Acked-by: Pavel Emelyanov <xemul@parallels.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-06-27unix_diag: Do not use RTA_PUT() macrosThomas Graf
Also, no need to trim on nlmsg_put() failure, nothing has been added yet. We also want to use nlmsg_end(), nlmsg_new() and nlmsg_free(). Signed-off-by: Thomas Graf <tgraf@suug.ch> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-06-26unix_diag: Move away from NLMSG_PUT().David S. Miller
And use nlmsg_data() while we're here too and remove useless casts. Signed-off-by: David S. Miller <davem@davemloft.net>
2012-06-09af_unix: remove unix_iter_stateEric Dumazet
As pointed out by Michael Tokarev , struct unix_iter_state is no longer needed. Suggested-by: Michael Tokarev <mjt@tls.msk.ru> Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Steven Whitehouse <swhiteho@redhat.com> Cc: Pavel Emelyanov <xemul@parallels.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-06-08af_unix: speedup /proc/net/unixEric Dumazet
/proc/net/unix has quadratic behavior, and can hold unix_table_lock for a while if high number of unix sockets are alive. (90 ms for 200k sockets...) We already have a hash table, so its quite easy to use it. Problem is unbound sockets are still hashed in a single hash slot (unix_socket_table[UNIX_HASH_TABLE]) This patch also spreads unbound sockets to 256 hash slots, to speedup both /proc/net/unix and unix_diag. Time to read /proc/net/unix with 200k unix sockets : (time dd if=/proc/net/unix of=/dev/null bs=4k) before : 520 secs after : 2 secs Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Steven Whitehouse <swhiteho@redhat.com> Cc: Pavel Emelyanov <xemul@parallels.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-04-25net: sock_diag_handler structs can be constShan Wei
read only, so change it to const. Signed-off-by: Shan Wei <davidshan@tencent.com> Acked-by: Pavel Emelyanov <xemul@parallels.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-04-20net: Convert all sysctl registrations to register_net_sysctlEric W. Biederman
This results in code with less boiler plate that is a bit easier to read. Additionally stops us from using compatibility code in the sysctl core, hastening the day when the compatibility code can be removed. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Acked-by: Pavel Emelyanov <xemul@parallels.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-04-20net: Move all of the network sysctls without a namespace into init_net.Eric W. Biederman
This makes it clearer which sysctls are relative to your current network namespace. This makes it a little less error prone by not exposing sysctls for the initial network namespace in other namespaces. This is the same way we handle all of our other network interfaces to userspace and I can't honestly remember why we didn't do this for sysctls right from the start. Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Acked-by: Pavel Emelyanov <xemul@parallels.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-04-15net: cleanup unsigned to unsigned intEric Dumazet
Use of "unsigned int" is preferred to bare "unsigned" in net tree. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-04-03af_unix: reduce high order page allocationsEric Dumazet
unix_dgram_sendmsg() currently builds linear skbs, and this can stress page allocator with high order page allocations. When memory gets fragmented, this can eventually fail. We can try to use order-2 allocations for skb head (SKB_MAX_ALLOC) plus up to 16 page fragments to lower pressure on buddy allocator. This patch has no effect on messages of less than 16064 bytes. (on 64bit arches with PAGE_SIZE=4096) For bigger messages (from 16065 to 81600 bytes), this patch brings reliability at the expense of performance penalty because of extra pages allocations. netperf -t DG_STREAM -T 0,2 -- -m 16064 -s 200000 ->4086040 Messages / 10s netperf -t DG_STREAM -T 0,2 -- -m 16068 -s 200000 ->3901747 Messages / 10s Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-03-23poll: add poll_requested_events() and poll_does_not_wait() functionsHans Verkuil
In some cases the poll() implementation in a driver has to do different things depending on the events the caller wants to poll for. An example is when a driver needs to start a DMA engine if the caller polls for POLLIN, but doesn't want to do that if POLLIN is not requested but instead only POLLOUT or POLLPRI is requested. This is something that can happen in the video4linux subsystem among others. Unfortunately, the current epoll/poll/select implementation doesn't provide that information reliably. The poll_table_struct does have it: it has a key field with the event mask. But once a poll() call matches one or more bits of that mask any following poll() calls are passed a NULL poll_table pointer. Also, the eventpoll implementation always left the key field at ~0 instead of using the requested events mask. This was changed in eventpoll.c so the key field now contains the actual events that should be polled for as set by the caller. The solution to the NULL poll_table pointer is to set the qproc field to NULL in poll_table once poll() matches the events, not the poll_table pointer itself. That way drivers can obtain the mask through a new poll_requested_events inline. The poll_table_struct can still be NULL since some kernel code calls it internally (netfs_state_poll() in ./drivers/staging/pohmelfs/netfs.h). In that case poll_requested_events() returns ~0 (i.e. all events). Very rarely drivers might want to know whether poll_wait will actually wait. If another earlier file descriptor in the set already matched the events the caller wanted to wait for, then the kernel will return from the select() call without waiting. This might be useful information in order to avoid doing expensive work. A new helper function poll_does_not_wait() is added that drivers can use to detect this situation. This is now used in sock_poll_wait() in include/net/sock.h. This was the only place in the kernel that needed this information. Drivers should no longer access any of the poll_table internals, but use the poll_requested_events() and poll_does_not_wait() access functions instead. In order to enforce that the poll_table fields are now prepended with an underscore and a comment was added warning against using them directly. This required a change in unix_dgram_poll() in unix/af_unix.c which used the key field to get the requested events. It's been replaced by a call to poll_requested_events(). For qproc it was especially important to change its name since the behavior of that field changes with this patch since this function pointer can now be NULL when that wasn't possible in the past. Any driver accessing the qproc or key fields directly will now fail to compile. Some notes regarding the correctness of this patch: the driver's poll() function is called with a 'struct poll_table_struct *wait' argument. This pointer may or may not be NULL, drivers can never rely on it being one or the other as that depends on whether or not an earlier file descriptor in the select()'s fdset matched the requested events. There are only three things a driver can do with the wait argument: 1) obtain the key field: events = wait ? wait->key : ~0; This will still work although it should be replaced with the new poll_requested_events() function (which does exactly the same). This will now even work better, since wait is no longer set to NULL unnecessarily. 2) use the qproc callback. This could be deadly since qproc can now be NULL. Renaming qproc should prevent this from happening. There are no kernel drivers that actually access this callback directly, BTW. 3) test whether wait == NULL to determine whether poll would return without waiting. This is no longer sufficient as the correct test is now wait == NULL || wait->_qproc == NULL. However, the worst that can happen here is a slight performance hit in the case where wait != NULL and wait->_qproc == NULL. In that case the driver will assume that poll_wait() will actually add the fd to the set of waiting file descriptors. Of course, poll_wait() will not do that since it tests for wait->_qproc. This will not break anything, though. There is only one place in the whole kernel where this happens (sock_poll_wait() in include/net/sock.h) and that code will be replaced by a call to poll_does_not_wait() in the next patch. Note that even if wait->_qproc != NULL drivers cannot rely on poll_wait() actually waiting. The next file descriptor from the set might match the event mask and thus any possible waits will never happen. Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Reviewed-by: Jonathan Corbet <corbet@lwn.net> Reviewed-by: Al Viro <viro@zeniv.linux.org.uk> Cc: Davide Libenzi <davidel@xmailserver.org> Signed-off-by: Hans de Goede <hdegoede@redhat.com> Cc: Mauro Carvalho Chehab <mchehab@infradead.org> Cc: David Miller <davem@davemloft.net> Cc: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-03-21Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull vfs pile 1 from Al Viro: "This is _not_ all; in particular, Miklos' and Jan's stuff is not there yet." * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (64 commits) ext4: initialization of ext4_li_mtx needs to be done earlier debugfs-related mode_t whack-a-mole hfsplus: add an ioctl to bless files hfsplus: change finder_info to u32 hfsplus: initialise userflags qnx4: new helper - try_extent() qnx4: get rid of qnx4_bread/qnx4_getblk take removal of PF_FORKNOEXEC to flush_old_exec() trim includes in inode.c um: uml_dup_mmap() relies on ->mmap_sem being held, but activate_mm() doesn't hold it um: embed ->stub_pages[] into mmu_context gadgetfs: list_for_each_safe() misuse ocfs2: fix leaks on failure exits in module_init ecryptfs: make register_filesystem() the last potential failure exit ntfs: forgets to unregister sysctls on register_filesystem() failure logfs: missing cleanup on register_filesystem() failure jfs: mising cleanup on register_filesystem() failure make configfs_pin_fs() return root dentry on success configfs: configfs_create_dir() has parent dentry in dentry->d_parent configfs: sanitize configfs_create() ...
2012-03-20switch touch_atime to struct pathAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-03-20switch unix_sock to struct pathAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2012-02-26netlink: add netlink_dump_control structure for netlink_dump_start()Pablo Neira Ayuso
Davem considers that the argument list of this interface is getting out of control. This patch tries to address this issue following his proposal: struct netlink_dump_control c = { .dump = dump, .done = done, ... }; netlink_dump_start(..., &c); Suggested by David S. Miller. Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-02-22af_unix: MSG_TRUNC support for dgram socketsEric Dumazet
Piergiorgio Beruto expressed the need to fetch size of first datagram in queue for AF_UNIX sockets and suggested a patch against SIOCINQ ioctl. I suggested instead to implement MSG_TRUNC support as a recv() input flag, as already done for RAW, UDP & NETLINK sockets. len = recv(fd, &byte, 1, MSG_PEEK | MSG_TRUNC); MSG_TRUNC asks recv() to return the real length of the packet, even when is was longer than the passed buffer. There is risk that a userland application used MSG_TRUNC by accident (since it had no effect on af_unix sockets) and this might break after this patch. Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Tested-by: Piergiorgio Beruto <piergiorgio.beruto@gmail.com> CC: Michael Kerrisk <mtk.manpages@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-02-21unix: Support peeking offset for stream socketsPavel Emelyanov
The same here -- we can protect the sk_peek_off manipulations with the unix_sk->readlock mutex. The peeking of data from a stream socket is done in the datagram style, i.e. even if there's enough room for more data in the user buffer, only the head skb's data is copied in there. This feature is preserved when peeking data from a given offset -- the data is read till the nearest skb's boundary. Signed-off-by: Pavel Emelyanov <xemul@parallels.com> Acked-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-02-21unix: Support peeking offset for datagram and seqpacket socketsPavel Emelyanov
The sk_peek_off manipulations are protected with the unix_sk->readlock mutex. This mutex is enough since all we need is to syncronize setting the offset vs reading the queue head. The latter is fully covered with the mentioned lock. The recently added __skb_recv_datagram's offset is used to pick the skb to read the data from. Signed-off-by: Pavel Emelyanov <xemul@parallels.com> Acked-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-01-30af_unix: fix EPOLLET regression for stream socketsEric Dumazet
Commit 0884d7aa24 (AF_UNIX: Fix poll blocking problem when reading from a stream socket) added a regression for epoll() in Edge Triggered mode (EPOLLET) Appropriate fix is to use skb_peek()/skb_unlink() instead of skb_dequeue(), and only call skb_unlink() when skb is fully consumed. This remove the need to requeue a partial skb into sk_receive_queue head and the extra sk->sk_data_ready() calls that added the regression. This is safe because once skb is given to sk_receive_queue, it is not modified by a writer, and readers are serialized by u->readlock mutex. This also reduce number of spinlock acquisition for small reads or MSG_PEEK users so should improve overall performance. Reported-by: Nick Mathewson <nickm@freehaven.net> Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Cc: Alexey Moiseytsev <himeraster@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2012-01-09Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netLinus Torvalds
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: igmp: Avoid zero delay when receiving odd mixture of IGMP queries netdev: make net_device_ops const bcm63xx: make ethtool_ops const usbnet: make ethtool_ops const net: Fix build with INET disabled. net: introduce netif_addr_lock_nested() and call if when appropriate net: correct lock name in dev_[uc/mc]_sync documentations. net: sk_update_clone is only used in net/core/sock.c 8139cp: fix missing napi_gro_flush. pktgen: set correct max and min in pktgen_setup_inject() smsc911x: Unconditionally include linux/smscphy.h in smsc911x.h asix: fix infinite loop in rx_fixup() net: Default UDP and UNIX diag to 'n'. r6040: fix typo in use of MCR0 register bits net: fix sock_clone reference mismatch with tcp memcontrol
2012-01-08Merge branch 'for-linus2' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs * 'for-linus2' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (165 commits) reiserfs: Properly display mount options in /proc/mounts vfs: prevent remount read-only if pending removes vfs: count unlinked inodes vfs: protect remounting superblock read-only vfs: keep list of mounts for each superblock vfs: switch ->show_options() to struct dentry * vfs: switch ->show_path() to struct dentry * vfs: switch ->show_devname() to struct dentry * vfs: switch ->show_stats to struct dentry * switch security_path_chmod() to struct path * vfs: prefer ->dentry->d_sb to ->mnt->mnt_sb vfs: trim includes a bit switch mnt_namespace ->root to struct mount vfs: take /proc/*/mounts and friends to fs/proc_namespace.c vfs: opencode mntget() mnt_set_mountpoint() vfs: spread struct mount - remaining argument of next_mnt() vfs: move fsnotify junk to struct mount vfs: move mnt_devname vfs: move mnt_list to struct mount vfs: switch pnode.h macros to struct mount * ...
2012-01-07net: Default UDP and UNIX diag to 'n'.David S. Miller
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-01-03switch ->path_mknod() to umode_tAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-12-30unix_diag: Fixup RQLEN extension reportPavel Emelyanov
While it's not too late fix the recently added RQLEN diag extension to report rqlen and wqlen in the same way as TCP does. I.e. for listening sockets the ack backlog length (which is the input queue length for socket) in rqlen and the max ack backlog length in wqlen, and what the CINQ/OUTQ ioctls do for established. Signed-off-by: Pavel Emelyanov <xemul@parallels.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-12-30af_unix: Move CINQ/COUTQ code to helpersPavel Emelyanov
Currently tcp diag reports rqlen and wqlen values similar to how the CINQ/COUTQ iotcls do. To make unix diag report these values in the same way move the respective code into helpers. Signed-off-by: Pavel Emelyanov <xemul@parallels.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-12-30unix_diag: Add the MEMINFO extensionPavel Emelyanov
[ Fix indentation of sock_diag*() calls. -DaveM ] Signed-off-by: Pavel Emelyanov <xemul@parallels.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-12-26unix: If we happen to find peer NULL when diag dumping, write zero.David S. Miller
Otherwise we leave uninitialized kernel memory in there. Reported-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-12-26unix_diag: Fix incoming connections nla lengthPavel Emelyanov
The NLA_PUT macro should accept the actual attribute length, not the amount of elements in array :( Signed-off-by: Pavel Emelyanov <xemul@parallels.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-12-20net: unix -- Add missing module.h inclusionCyrill Gorcunov
Otherwise getting | net/unix/diag.c:312:16: error: expected declaration specifiers or ‘...’ before string constant | net/unix/diag.c:313:1: error: expected declaration specifiers or ‘...’ before string constant Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-12-16unix_diag: Write it into kbuildPavel Emelyanov
Signed-off-by: Pavel Emelyanov <xemul@parallels.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-12-16unix_diag: Receive queue lenght NLAPavel Emelyanov
Signed-off-by: Pavel Emelyanov <xemul@parallels.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-12-16unix_diag: Pending connections IDs NLAPavel Emelyanov
When establishing a unix connection on stream sockets the server end receives an skb with socket in its receive queue. Report who is waiting for these ends to be accepted for listening sockets via NLA. There's a lokcing issue with this -- the unix sk state lock is required to access the peer, and it is taken under the listening sk's queue lock. Strictly speaking the queue lock should be taken inside the state lock, but since in this case these two sockets are different it shouldn't lead to deadlock. Signed-off-by: Pavel Emelyanov <xemul@parallels.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-12-16unix_diag: Unix peer inode NLAPavel Emelyanov
Report the peer socket inode ID as NLA. With this it's finally possible to find out the other end of an interesting unix connection. Signed-off-by: Pavel Emelyanov <xemul@parallels.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-12-16unix_diag: Unix inode info NLAPavel Emelyanov
Actually, the socket path if it's not anonymous doesn't give a clue to which file the socket is bound to. Even if the path is absolute, it can be unlinked and then new socket can be bound to it. With this NLA it's possible to check which file a particular socket is really bound to. Signed-off-by: Pavel Emelyanov <xemul@parallels.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-12-16unix_diag: Unix socket name NLAPavel Emelyanov
Report the sun_path when requested as NLA. With leading '\0' if present but without the leading AF_UNIX bits. Signed-off-by: Pavel Emelyanov <xemul@parallels.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-12-16unix_diag: Dumping exact socket corePavel Emelyanov
The socket inode is used as a key for lookup. This is effectively the only really unique ID of a unix socket, but using this for search currently has one problem -- it is O(number of sockets) :( Does it worth fixing this lookup or inventing some other ID for unix sockets? Signed-off-by: Pavel Emelyanov <xemul@parallels.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-12-16unix_diag: Dumping all sockets corePavel Emelyanov
Walk the unix sockets table and fill the core response structure, which includes type, state and inode. Signed-off-by: Pavel Emelyanov <xemul@parallels.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-12-16unix_diag: Basic module skeletonPavel Emelyanov
Includes basic module_init/_exit functionality, dump/get_exact stubs and declares the basic API structures for request and response. Signed-off-by: Pavel Emelyanov <xemul@parallels.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-12-16af_unix: Export stuff required for diag modulePavel Emelyanov
Signed-off-by: Pavel Emelyanov <xemul@parallels.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-11-26AF_UNIX: Fix poll blocking problem when reading from a stream socketAlexey Moiseytsev
poll() call may be blocked by concurrent reading from the same stream socket. Signed-off-by: Alexey Moiseytsev <himeraster@gmail.com> Acked-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-09-28af_unix: dont send SCM_CREDENTIALS by defaultEric Dumazet
Since commit 7361c36c5224 (af_unix: Allow credentials to work across user and pid namespaces) af_unix performance dropped a lot. This is because we now take a reference on pid and cred in each write(), and release them in read(), usually done from another process, eventually from another cpu. This triggers false sharing. # Events: 154K cycles # # Overhead Command Shared Object Symbol # ........ ....... .................. ......................... # 10.40% hackbench [kernel.kallsyms] [k] put_pid 8.60% hackbench [kernel.kallsyms] [k] unix_stream_recvmsg 7.87% hackbench [kernel.kallsyms] [k] unix_stream_sendmsg 6.11% hackbench [kernel.kallsyms] [k] do_raw_spin_lock 4.95% hackbench [kernel.kallsyms] [k] unix_scm_to_skb 4.87% hackbench [kernel.kallsyms] [k] pid_nr_ns 4.34% hackbench [kernel.kallsyms] [k] cred_to_ucred 2.39% hackbench [kernel.kallsyms] [k] unix_destruct_scm 2.24% hackbench [kernel.kallsyms] [k] sub_preempt_count 1.75% hackbench [kernel.kallsyms] [k] fget_light 1.51% hackbench [kernel.kallsyms] [k] __mutex_lock_interruptible_slowpath 1.42% hackbench [kernel.kallsyms] [k] sock_alloc_send_pskb This patch includes SCM_CREDENTIALS information in a af_unix message/skb only if requested by the sender, [man 7 unix for details how to include ancillary data using sendmsg() system call] Note: This might break buggy applications that expected SCM_CREDENTIAL from an unaware write() system call, and receiver not using SO_PASSCRED socket option. If SOCK_PASSCRED is set on source or destination socket, we still include credentials for mere write() syscalls. Performance boost in hackbench : more than 50% gain on a 16 thread machine (2 quad-core cpus, 2 threads per core) hackbench 20 thread 2000 4.228 sec instead of 9.102 sec Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Acked-by: Tim Chen <tim.c.chen@linux.intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-09-16Revert "Scm: Remove unnecessary pid & credential references in Unix socket's ↵David S. Miller
send and receive path" This reverts commit 0856a304091b33a8e8f9f9c98e776f425af2b625. As requested by Eric Dumazet, it has various ref-counting problems and has introduced regressions. Eric will add a more suitable version of this performance fix. Signed-off-by: David S. Miller <davem@davemloft.net>
2011-08-24Scm: Remove unnecessary pid & credential references in Unix socket's send ↵Tim Chen
and receive path Patch series 109f6e39..7361c36c back in 2.6.36 added functionality to allow credentials to work across pid namespaces for packets sent via UNIX sockets. However, the atomic reference counts on pid and credentials caused plenty of cache bouncing when there are numerous threads of the same pid sharing a UNIX socket. This patch mitigates the problem by eliminating extraneous reference counts on pid and credentials on both send and receive path of UNIX sockets. I found a 2x improvement in hackbench's threaded case. On the receive path in unix_dgram_recvmsg, currently there is an increment of reference count on pid and credentials in scm_set_cred. Then there are two decrement of the reference counts. Once in scm_recv and once when skb_free_datagram call skb->destructor function unix_destruct_scm. One pair of increment and decrement of ref count on pid and credentials can be eliminated from the receive path. Until we destroy the skb, we already set a reference when we created the skb on the send side. On the send path, there are two increments of ref count on pid and credentials, once in scm_send and once in unix_scm_to_skb. Then there is a decrement of the reference counts in scm_destroy's call to scm_destroy_cred at the end of unix_dgram_sendmsg functions. One pair of increment and decrement of the reference counts can be removed so we only need to increment the ref counts once. By incorporating these changes, for hackbench running on a 4 socket NHM-EX machine with 40 cores, the execution of hackbench on 50 groups of 20 threads sped up by factor of 2. Hackbench command used for testing: ./hackbench 50 thread 2000 Signed-off-by: Tim Chen <tim.c.chen@linux.intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2011-07-20new helpers: kern_path_create/user_path_createAl Viro
combination of kern_path_parent() and lookup_create(). Does *not* expose struct nameidata to caller. Syscalls converted to that... Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2011-05-24net: convert %p usage to %pKDan Rosenberg
The %pK format specifier is designed to hide exposed kernel pointers, specifically via /proc interfaces. Exposing these pointers provides an easy target for kernel write vulnerabilities, since they reveal the locations of writable structures containing easily triggerable function pointers. The behavior of %pK depends on the kptr_restrict sysctl. If kptr_restrict is set to 0, no deviation from the standard %p behavior occurs. If kptr_restrict is set to 1, the default, if the current user (intended to be a reader via seq_printf(), etc.) does not have CAP_SYSLOG (currently in the LSM tree), kernel pointers using %pK are printed as 0's. If kptr_restrict is set to 2, kernel pointers using %pK are printed as 0's regardless of privileges. Replacing with 0's was chosen over the default "(null)", which cannot be parsed by userland %p, which expects "(nil)". The supporting code for kptr_restrict and %pK are currently in the -mm tree. This patch converts users of %p in net/ to %pK. Cases of printing pointers to the syslog are not covered, since this would eliminate useful information for postmortem debugging and the reading of the syslog is already optionally protected by the dmesg_restrict sysctl. Signed-off-by: Dan Rosenberg <drosenberg@vsecurity.com> Cc: James Morris <jmorris@namei.org> Cc: Eric Dumazet <eric.dumazet@gmail.com> Cc: Thomas Graf <tgraf@infradead.org> Cc: Eugene Teo <eugeneteo@kernel.org> Cc: Kees Cook <kees.cook@canonical.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: David S. Miller <davem@davemloft.net> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Eric Paris <eparis@parisplace.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: David S. Miller <davem@davemloft.net>