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* poll: add poll_requested_events() and poll_does_not_wait() functionsHans Verkuil2012-03-231-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* Merge branch 'for-linus' of ↵Linus Torvalds2012-03-212-22/+17
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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() ...
| * switch touch_atime to struct pathAl Viro2012-03-201-2/+2
| | | | | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * switch unix_sock to struct pathAl Viro2012-03-202-21/+16
| | | | | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | netlink: add netlink_dump_control structure for netlink_dump_start()Pablo Neira Ayuso2012-02-261-4/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* | af_unix: MSG_TRUNC support for dgram socketsEric Dumazet2012-02-221-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* | unix: Support peeking offset for stream socketsPavel Emelyanov2012-02-211-2/+18
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* | unix: Support peeking offset for datagram and seqpacket socketsPavel Emelyanov2012-02-211-5/+25
|/ | | | | | | | | | | | | 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>
* af_unix: fix EPOLLET regression for stream socketsEric Dumazet2012-01-301-15/+4
| | | | | | | | | | | | | | | | | | | | | | | 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>
* Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netLinus Torvalds2012-01-091-1/+1
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * 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
| * net: Default UDP and UNIX diag to 'n'.David S. Miller2012-01-071-1/+1
| | | | | | | | Signed-off-by: David S. Miller <davem@davemloft.net>
* | Merge branch 'for-linus2' of ↵Linus Torvalds2012-01-081-1/+1
|\ \ | |/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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 * ...
| * switch ->path_mknod() to umode_tAl Viro2012-01-031-1/+1
| | | | | | | | Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* | unix_diag: Fixup RQLEN extension reportPavel Emelyanov2011-12-301-1/+12
| | | | | | | | | | | | | | | | | | | | | | | | 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>
* | af_unix: Move CINQ/COUTQ code to helpersPavel Emelyanov2011-12-301-23/+36
| | | | | | | | | | | | | | | | | | 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>
* | unix_diag: Add the MEMINFO extensionPavel Emelyanov2011-12-301-8/+12
| | | | | | | | | | | | | | [ Fix indentation of sock_diag*() calls. -DaveM ] Signed-off-by: Pavel Emelyanov <xemul@parallels.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | unix: If we happen to find peer NULL when diag dumping, write zero.David S. Miller2011-12-261-2/+1
| | | | | | | | | | | | | | 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>
* | unix_diag: Fix incoming connections nla lengthPavel Emelyanov2011-12-261-1/+2
| | | | | | | | | | | | | | | | 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>
* | net: unix -- Add missing module.h inclusionCyrill Gorcunov2011-12-201-0/+1
| | | | | | | | | | | | | | | | | | | | 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>
* | unix_diag: Write it into kbuildPavel Emelyanov2011-12-162-0/+10
| | | | | | | | | | Signed-off-by: Pavel Emelyanov <xemul@parallels.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | unix_diag: Receive queue lenght NLAPavel Emelyanov2011-12-161-0/+13
| | | | | | | | | | Signed-off-by: Pavel Emelyanov <xemul@parallels.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* | unix_diag: Pending connections IDs NLAPavel Emelyanov2011-12-161-0/+39
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* | unix_diag: Unix peer inode NLAPavel Emelyanov2011-12-161-0/+24
| | | | | | | | | | | | | | | | 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>
* | unix_diag: Unix inode info NLAPavel Emelyanov2011-12-161-0/+21
| | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* | unix_diag: Unix socket name NLAPavel Emelyanov2011-12-161-0/+20
| | | | | | | | | | | | | | | | 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>
* | unix_diag: Dumping exact socket corePavel Emelyanov2011-12-161-1/+66
| | | | | | | | | | | | | | | | | | | | | | | | 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>
* | unix_diag: Dumping all sockets corePavel Emelyanov2011-12-161-1/+75
| | | | | | | | | | | | | | | | 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>
* | unix_diag: Basic module skeletonPavel Emelyanov2011-12-161-0/+57
| | | | | | | | | | | | | | | | 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>
* | af_unix: Export stuff required for diag modulePavel Emelyanov2011-12-161-3/+6
|/ | | | | Signed-off-by: Pavel Emelyanov <xemul@parallels.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* AF_UNIX: Fix poll blocking problem when reading from a stream socketAlexey Moiseytsev2011-11-261-0/+4
| | | | | | | | | 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>
* af_unix: dont send SCM_CREDENTIALS by defaultEric Dumazet2011-09-281-1/+23
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* Revert "Scm: Remove unnecessary pid & credential references in Unix socket's ↵David S. Miller2011-09-161-29/+16
| | | | | | | | | | | | 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>
* Scm: Remove unnecessary pid & credential references in Unix socket's send ↵Tim Chen2011-08-241-16/+29
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* new helpers: kern_path_create/user_path_createAl Viro2011-07-201-21/+17
| | | | | | | 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>
* net: convert %p usage to %pKDan Rosenberg2011-05-241-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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>
* af_unix: Only allow recv on connected seqpacket sockets.Eric W. Biederman2011-05-011-1/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This fixes the following oops discovered by Dan Aloni: > Anyway, the following is the output of the Oops that I got on the > Ubuntu kernel on which I first detected the problem > (2.6.37-12-generic). The Oops that followed will be more useful, I > guess. >[ 5594.669852] BUG: unable to handle kernel NULL pointer dereference > at           (null) > [ 5594.681606] IP: [<ffffffff81550b7b>] unix_dgram_recvmsg+0x1fb/0x420 > [ 5594.687576] PGD 2a05d067 PUD 2b951067 PMD 0 > [ 5594.693720] Oops: 0002 [#1] SMP > [ 5594.699888] last sysfs file: The bug was that unix domain sockets use a pseduo packet for connecting and accept uses that psudo packet to get the socket. In the buggy seqpacket case we were allowing unconnected sockets to call recvmsg and try to receive the pseudo packet. That is always wrong and as of commit 7361c36c5 the pseudo packet had become enough different from a normal packet that the kernel started oopsing. Do for seqpacket_recv what was done for seqpacket_send in 2.5 and only allow it on connected seqpacket sockets. Cc: stable@kernel.org Tested-by: Dan Aloni <dan@aloni.org> Signed-off-by: Eric W. Biederman <ebiederm@xmission.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* Fix common misspellingsLucas De Marchi2011-03-311-1/+1
| | | | | | Fixes generated by 'codespell' and manually reviewed. Signed-off-by: Lucas De Marchi <lucas.demarchi@profusion.mobi>
* Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next-2.6Linus Torvalds2011-03-161-33/+39
|\ | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | * git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next-2.6: (1480 commits) bonding: enable netpoll without checking link status xfrm: Refcount destination entry on xfrm_lookup net: introduce rx_handler results and logic around that bonding: get rid of IFF_SLAVE_INACTIVE netdev->priv_flag bonding: wrap slave state work net: get rid of multiple bond-related netdevice->priv_flags bonding: register slave pointer for rx_handler be2net: Bump up the version number be2net: Copyright notice change. Update to Emulex instead of ServerEngines e1000e: fix kconfig for crc32 dependency netfilter ebtables: fix xt_AUDIT to work with ebtables xen network backend driver bonding: Improve syslog message at device creation time bonding: Call netif_carrier_off after register_netdevice bonding: Incorrect TX queue offset net_sched: fix ip_tos2prio xfrm: fix __xfrm_route_forward() be2net: Fix UDP packet detected status in RX compl Phonet: fix aligned-mode pipe socket buffer header reserve netxen: support for GbE port settings ... Fix up conflicts in drivers/staging/brcm80211/brcmsmac/wl_mac80211.c with the staging updates.
| * Merge branch 'master' of ↵David S. Miller2011-03-151-1/+1
| |\ | | | | | | | | | master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6
| | * af_unix: update locking commentDaniel Baluta2011-03-141-1/+1
| | | | | | | | | | | | | | | | | | | | | We latch our state using a spinlock not a r/w kind of lock. Signed-off-by: Daniel Baluta <dbaluta@ixiacom.com> Signed-off-by: David S. Miller <davem@davemloft.net>
| * | Merge branch 'master' of ↵David S. Miller2011-03-101-4/+13
| |\| | | | | | | | | | | | | | | | | | | master.kernel.org:/pub/scm/linux/kernel/git/davem/net-2.6 Conflicts: drivers/net/bnx2x/bnx2x_cmn.c
| * | af_unix: remove unused struct sockaddr_un cruftHagen Paul Pfeifer2011-03-071-2/+0
| | | | | | | | | | | | | | | Signed-off-by: Hagen Paul Pfeifer <hagen@jauu.net> Signed-off-by: David S. Miller <davem@davemloft.net>
| * | net: add __rcu annotations to sk_wq and wqEric Dumazet2011-02-221-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Add proper RCU annotations/verbs to sk_wq and wq members Fix __sctp_write_space() sk_sleep() abuse (and sock->wq access) Fix sunrpc sk_sleep() abuse too Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
| * | af_unix: coding style: remove one level of indentation in unix_shutdown()Alban Crequy2011-01-191-29/+31
| | | | | | | | | | | | | | | | | | Signed-off-by: Alban Crequy <alban.crequy@collabora.co.uk> Reviewed-by: Ian Molton <ian.molton@collabora.co.uk> Signed-off-by: David S. Miller <davem@davemloft.net>
| * | af_unix: implement socket filterAlban Crequy2011-01-181-0/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Linux Socket Filters can already be successfully attached and detached on unix sockets with setsockopt(sockfd, SOL_SOCKET, SO_{ATTACH,DETACH}_FILTER, ...). See: Documentation/networking/filter.txt But the filter was never used in the unix socket code so it did not work. This patch uses sk_filter() to filter buffers before delivery. This short program demonstrates the problem on SOCK_DGRAM. int main(void) { int i, j, ret; int sv[2]; struct pollfd fds[2]; char *message = "Hello world!"; char buffer[64]; struct sock_filter ins[32] = {{0,},}; struct sock_fprog filter; socketpair(AF_UNIX, SOCK_DGRAM, 0, sv); for (i = 0 ; i < 2 ; i++) { fds[i].fd = sv[i]; fds[i].events = POLLIN; fds[i].revents = 0; } for(j = 1 ; j < 13 ; j++) { /* Set a socket filter to truncate the message */ memset(ins, 0, sizeof(ins)); ins[0].code = BPF_RET|BPF_K; ins[0].k = j; filter.len = 1; filter.filter = ins; setsockopt(sv[1], SOL_SOCKET, SO_ATTACH_FILTER, &filter, sizeof(filter)); /* send a message */ send(sv[0], message, strlen(message) + 1, 0); /* The filter should let the message pass but truncated. */ poll(fds, 2, 0); /* Receive the truncated message*/ ret = recv(sv[1], buffer, 64, 0); printf("received %d bytes, expected %d\n", ret, j); } for (i = 0 ; i < 2 ; i++) close(sv[i]); return 0; } Signed-off-by: Alban Crequy <alban.crequy@collabora.co.uk> Reviewed-by: Ian Molton <ian.molton@collabora.co.uk> Signed-off-by: David S. Miller <davem@davemloft.net>
* | | Merge branch 'for-linus' of ↵Linus Torvalds2011-03-152-2/+2
|\ \ \ | |_|/ |/| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6 * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6: (57 commits) tidy the trailing symlinks traversal up Turn resolution of trailing symlinks iterative everywhere simplify link_path_walk() tail Make trailing symlink resolution in path_lookupat() iterative update nd->inode in __do_follow_link() instead of after do_follow_link() pull handling of one pathname component into a helper fs: allow AT_EMPTY_PATH in linkat(), limit that to CAP_DAC_READ_SEARCH Allow passing O_PATH descriptors via SCM_RIGHTS datagrams readlinkat(), fchownat() and fstatat() with empty relative pathnames Allow O_PATH for symlinks New kind of open files - "location only". ext4: Copy fs UUID to superblock ext3: Copy fs UUID to superblock. vfs: Export file system uuid via /proc/<pid>/mountinfo unistd.h: Add new syscalls numbers to asm-generic x86: Add new syscalls for x86_64 x86: Add new syscalls for x86_32 fs: Remove i_nlink check from file system link callback fs: Don't allow to create hardlink for deleted file vfs: Add open by file handle support ...
| * | Allow passing O_PATH descriptors via SCM_RIGHTS datagramsAl Viro2011-03-151-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | Just need to make sure that AF_UNIX garbage collector won't confuse O_PATHed socket on filesystem for real AF_UNIX opened socket. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
| * | kill path_lookup()Al Viro2011-03-141-1/+1
| |/ | | | | | | | | | | | | all remaining callers pass LOOKUP_PARENT to it, so flags argument can die; renamed to kern_path_parent() Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
* / net: fix multithreaded signal handling in unix recv routinesRainer Weikusat2011-03-071-4/+13
|/ | | | | | | | | | | | | | | | | | | | | | | | The unix_dgram_recvmsg and unix_stream_recvmsg routines in net/af_unix.c utilize mutex_lock(&u->readlock) calls in order to serialize read operations of multiple threads on a single socket. This implies that, if all n threads of a process block in an AF_UNIX recv call trying to read data from the same socket, one of these threads will be sleeping in state TASK_INTERRUPTIBLE and all others in state TASK_UNINTERRUPTIBLE. Provided that a particular signal is supposed to be handled by a signal handler defined by the process and that none of this threads is blocking the signal, the complete_signal routine in kernel/signal.c will select the 'first' such thread it happens to encounter when deciding which thread to notify that a signal is supposed to be handled and if this is one of the TASK_UNINTERRUPTIBLE threads, the signal won't be handled until the one thread not blocking on the u->readlock mutex is woken up because some data to process has arrived (if this ever happens). The included patch fixes this by changing mutex_lock to mutex_lock_interruptible and handling possible error returns in the same way interruptions are handled by the actual receive-code. Signed-off-by: Rainer Weikusat <rweikusat@mobileactivedefense.com> Signed-off-by: David S. Miller <davem@davemloft.net>
* af_unix: Avoid socket->sk NULL OOPS in stream connect security hooks.David S. Miller2011-01-051-1/+1
| | | | | | | | | | | | | | | | unix_release() can asynchornously set socket->sk to NULL, and it does so without holding the unix_state_lock() on "other" during stream connects. However, the reverse mapping, sk->sk_socket, is only transitioned to NULL under the unix_state_lock(). Therefore make the security hooks follow the reverse mapping instead of the forward mapping. Reported-by: Jeremy Fitzhardinge <jeremy@goop.org> Reported-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: David S. Miller <davem@davemloft.net>
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