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  1. 02 11月, 2008 1 次提交
  3. 23 10月, 2008 1 次提交
  5. 14 10月, 2008 1 次提交
  7. 27 7月, 2008 1 次提交
  9. 26 7月, 2008 1 次提交
  11. 28 6月, 2008 1 次提交
    • R
      af_unix: fix 'poll for write'/connected DGRAM sockets · ec0d215f
      由 Rainer Weikusat 提交于 
      For n:1 'datagram connections' (eg /dev/log), the unix_dgram_sendmsg
routine implements a form of receiver-imposed flow control by
comparing the length of the receive queue of the 'peer socket' with
the max_ack_backlog value stored in the corresponding sock structure,
either blocking the thread which caused the send-routine to be called
or returning EAGAIN. This routine is used by both SOCK_DGRAM and
SOCK_SEQPACKET sockets. The poll-implementation for these socket types
is datagram_poll from core/datagram.c. A socket is deemed to be
writeable by this routine when the memory presently consumed by
datagrams owned by it is less than the configured socket send buffer
size. This is always wrong for PF_UNIX non-stream sockets connected to
server sockets dealing with (potentially) multiple clients if the
abovementioned receive queue is currently considered to be full.
'poll' will then return, indicating that the socket is writeable, but
a subsequent write result in EAGAIN, effectively causing an (usual)
application to 'poll for writeability by repeated send request with
O_NONBLOCK set' until it has consumed its time quantum.

The change below uses a suitably modified variant of the datagram_poll
routines for both type of PF_UNIX sockets, which tests if the
recv-queue of the peer a socket is connected to is presently
considered to be 'full' as part of the 'is this socket
writeable'-checking code. The socket being polled is additionally
put onto the peer_wait wait queue associated with its peer, because the
unix_dgram_recvmsg routine does a wake up on this queue after a
datagram was received and the 'other wakeup call' is done implicitly
as part of skb destruction, meaning, a process blocked in poll
because of a full peer receive queue could otherwise sleep forever
if no datagram owned by its socket was already sitting on this queue.
Among this change is a small (inline) helper routine named
'unix_recvq_full', which consolidates the actual testing code (in three
different places) into a single location.
Signed-off-by: NRainer Weikusat <rweikusat@mssgmbh.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      ec0d215f
  13. 18 6月, 2008 1 次提交
    • R
      af_unix: fix 'poll for write'/ connected DGRAM sockets · 3c73419c
      由 Rainer Weikusat 提交于 
      The unix_dgram_sendmsg routine implements a (somewhat crude)
form of receiver-imposed flow control by comparing the length of the
receive queue of the 'peer socket' with the max_ack_backlog value
stored in the corresponding sock structure, either blocking
the thread which caused the send-routine to be called or returning
EAGAIN. This routine is used by both SOCK_DGRAM and SOCK_SEQPACKET
sockets. The poll-implementation for these socket types is
datagram_poll from core/datagram.c. A socket is deemed to be writeable
by this routine when the memory presently consumed by datagrams
owned by it is less than the configured socket send buffer size. This
is always wrong for connected PF_UNIX non-stream sockets when the
abovementioned receive queue is currently considered to be full.
'poll' will then return, indicating that the socket is writeable, but
a subsequent write result in EAGAIN, effectively causing an
(usual) application to 'poll for writeability by repeated send request
with O_NONBLOCK set' until it has consumed its time quantum.

The change below uses a suitably modified variant of the datagram_poll
routines for both type of PF_UNIX sockets, which tests if the
recv-queue of the peer a socket is connected to is presently
considered to be 'full' as part of the 'is this socket
writeable'-checking code. The socket being polled is additionally
put onto the peer_wait wait queue associated with its peer, because the
unix_dgram_sendmsg routine does a wake up on this queue after a
datagram was received and the 'other wakeup call' is done implicitly
as part of skb destruction, meaning, a process blocked in poll
because of a full peer receive queue could otherwise sleep forever
if no datagram owned by its socket was already sitting on this queue.
Among this change is a small (inline) helper routine named
'unix_recvq_full', which consolidates the actual testing code (in three
different places) into a single location.
Signed-off-by: NRainer Weikusat <rweikusat@mssgmbh.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      3c73419c
  15. 12 6月, 2008 1 次提交
  17. 24 4月, 2008 1 次提交
  19. 19 4月, 2008 1 次提交
  21. 13 4月, 2008 1 次提交
  23. 26 3月, 2008 3 次提交
  25. 06 3月, 2008 1 次提交
  27. 15 2月, 2008 2 次提交
  29. 29 1月, 2008 9 次提交
  31. 29 11月, 2007 1 次提交
    • F
      [UNIX]: EOF on non-blocking SOCK_SEQPACKET · 0a112258
      由 Florian Zumbiehl 提交于 
      I am not absolutely sure whether this actually is a bug (as in: I've got
no clue what the standards say or what other implementations do), but at
least I was pretty surprised when I noticed that a recv() on a
non-blocking unix domain socket of type SOCK_SEQPACKET (which is connection
oriented, after all) where the remote end has closed the connection
returned -1 (EAGAIN) rather than 0 to indicate end of file.

This is a test case:

| #include <sys/types.h>
| #include <unistd.h>
| #include <sys/socket.h>
| #include <sys/un.h>
| #include <fcntl.h>
| #include <string.h>
| #include <stdlib.h>
| 
| int main(){
| 	int sock;
| 	struct sockaddr_un addr;
| 	char buf[4096];
| 	int pfds[2];
| 
| 	pipe(pfds);
| 	sock=socket(PF_UNIX,SOCK_SEQPACKET,0);
| 	addr.sun_family=AF_UNIX;
| 	strcpy(addr.sun_path,"/tmp/foobar_testsock");
| 	bind(sock,(struct sockaddr *)&addr,sizeof(addr));
| 	listen(sock,1);
| 	if(fork()){
| 		close(sock);
| 		sock=socket(PF_UNIX,SOCK_SEQPACKET,0);
| 		connect(sock,(struct sockaddr *)&addr,sizeof(addr));
| 		fcntl(sock,F_SETFL,fcntl(sock,F_GETFL)|O_NONBLOCK);
| 		close(pfds[1]);
| 		read(pfds[0],buf,sizeof(buf));
| 		recv(sock,buf,sizeof(buf),0); // <-- this one
| 	}else accept(sock,NULL,NULL);
| 	exit(0);
| }

If you try it, make sure /tmp/foobar_testsock doesn't exist.

The marked recv() returns -1 (EAGAIN) on 2.6.23.9. Below you find a
patch that fixes that.
Signed-off-by: NFlorian Zumbiehl <florz@florz.de>
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
      0a112258
  33. 11 11月, 2007 2 次提交
  35. 01 11月, 2007 1 次提交
  37. 20 10月, 2007 1 次提交
    • P
      pid namespaces: changes to show virtual ids to user · b488893a
      由 Pavel Emelyanov 提交于 
      This is the largest patch in the set. Make all (I hope) the places where
the pid is shown to or get from user operate on the virtual pids.

The idea is:
 - all in-kernel data structures must store either struct pid itself
   or the pid's global nr, obtained with pid_nr() call;
 - when seeking the task from kernel code with the stored id one
   should use find_task_by_pid() call that works with global pids;
 - when showing pid's numerical value to the user the virtual one
   should be used, but however when one shows task's pid outside this
   task's namespace the global one is to be used;
 - when getting the pid from userspace one need to consider this as
   the virtual one and use appropriate task/pid-searching functions.

[akpm@linux-foundation.org: build fix]
[akpm@linux-foundation.org: nuther build fix]
[akpm@linux-foundation.org: yet nuther build fix]
[akpm@linux-foundation.org: remove unneeded casts]
Signed-off-by: NPavel Emelyanov <xemul@openvz.org>
Signed-off-by: NAlexey Dobriyan <adobriyan@openvz.org>
Cc: Sukadev Bhattiprolu <sukadev@us.ibm.com>
Cc: Oleg Nesterov <oleg@tv-sign.ru>
Cc: Paul Menage <menage@google.com>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>
      b488893a
  39. 15 10月, 2007 1 次提交
    • I
      sched: affine sync wakeups · 71e20f18
      由 Ingo Molnar 提交于 
      make sync wakeups affine for cache-cold tasks: if a cache-cold task
is woken up by a sync wakeup then use the opportunity to migrate it
straight away. (the two tasks are 'related' because they communicate)
Signed-off-by: NIngo Molnar <mingo@elte.hu>
      71e20f18
  41. 11 10月, 2007 3 次提交
    • P
      [NET]: Make core networking code use seq_open_private · cf7732e4
      由 Pavel Emelyanov 提交于 
      This concerns the ipv4 and ipv6 code mostly, but also the netlink
and unix sockets.

The netlink code is an example of how to use the __seq_open_private()
call - it saves the net namespace on this private.
Signed-off-by: NPavel Emelyanov <xemul@openvz.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      cf7732e4
    • E
      [NET]: Make socket creation namespace safe. · 1b8d7ae4
      由 Eric W. Biederman 提交于 
      This patch passes in the namespace a new socket should be created in
and has the socket code do the appropriate reference counting.  By
virtue of this all socket create methods are touched.  In addition
the socket create methods are modified so that they will fail if
you attempt to create a socket in a non-default network namespace.

Failing if we attempt to create a socket outside of the default
network namespace ensures that as we incrementally make the network stack
network namespace aware we will not export functionality that someone
has not audited and made certain is network namespace safe.
Allowing us to partially enable network namespaces before all of the
exotic protocols are supported.

Any protocol layers I have missed will fail to compile because I now
pass an extra parameter into the socket creation code.

[ Integrated AF_IUCV build fixes from Andrew Morton... -DaveM ]
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      1b8d7ae4
    • E
      [NET]: Make /proc/net per network namespace · 457c4cbc
      由 Eric W. Biederman 提交于 
      This patch makes /proc/net per network namespace.  It modifies the global
variables proc_net and proc_net_stat to be per network namespace.
The proc_net file helpers are modified to take a network namespace argument,
and all of their callers are fixed to pass &init_net for that argument.
This ensures that all of the /proc/net files are only visible and
usable in the initial network namespace until the code behind them
has been updated to be handle multiple network namespaces.

Making /proc/net per namespace is necessary as at least some files
in /proc/net depend upon the set of network devices which is per
network namespace, and even more files in /proc/net have contents
that are relevant to a single network namespace.
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      457c4cbc
  43. 31 7月, 2007 1 次提交
  45. 12 7月, 2007 1 次提交
    • M
      [AF_UNIX]: Rewrite garbage collector, fixes race. · 1fd05ba5
      由 Miklos Szeredi 提交于 
      Throw out the old mark & sweep garbage collector and put in a
refcounting cycle detecting one.

The old one had a race with recvmsg, that resulted in false positives
and hence data loss.  The old algorithm operated on all unix sockets
in the system, so any additional locking would have meant performance
problems for all users of these.

The new algorithm instead only operates on "in flight" sockets, which
are very rare, and the additional locking for these doesn't negatively
impact the vast majority of users.

In fact it's probable, that there weren't *any* heavy senders of
sockets over sockets, otherwise the above race would have been
discovered long ago.

The patch works OK with the app that exposed the race with the old
code.  The garbage collection has also been verified to work in a few
simple cases.
Signed-off-by: NMiklos Szeredi <mszeredi@suse.cz>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      1fd05ba5
  47. 11 7月, 2007 1 次提交
  49. 08 6月, 2007 1 次提交
    • M
      [AF_UNIX]: Fix stream recvmsg() race. · 3c0d2f37
      由 Miklos Szeredi 提交于 
      A recv() on an AF_UNIX, SOCK_STREAM socket can race with a
send()+close() on the peer, causing recv() to return zero, even though
the sent data should be received.

This happens if the send() and the close() is performed between
skb_dequeue() and checking sk->sk_shutdown in unix_stream_recvmsg():

process A  skb_dequeue() returns NULL, there's no data in the socket queue
process B  new data is inserted onto the queue by unix_stream_sendmsg()
process B  sk->sk_shutdown is set to SHUTDOWN_MASK by unix_release_sock()
process A  sk->sk_shutdown is checked, unix_release_sock() returns zero

I'm surprised nobody noticed this, it's not hard to trigger.  Maybe
it's just (un)luck with the timing.

It's possible to work around this bug in userspace, by retrying the
recv() once in case of a zero return value.
Signed-off-by: NMiklos Szeredi <mszeredi@suse.cz>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      3c0d2f37
  51. 04 6月, 2007 1 次提交
    • D
      [AF_UNIX]: Fix datagram connect race causing an OOPS. · 278a3de5
      由 David S. Miller 提交于 
      Based upon an excellent bug report and initial patch by
Frederik Deweerdt.

The UNIX datagram connect code blindly dereferences other->sk_socket
via the call down to the security_unix_may_send() function.

Without locking 'other' that pointer can go NULL via unix_release_sock()
which does sock_orphan() which also marks the socket SOCK_DEAD.

So we have to lock both 'sk' and 'other' yet avoid all kinds of
potential deadlocks (connect to self is OK for datagram sockets and it
is possible for two datagram sockets to perform a simultaneous connect
to each other).  So what we do is have a "double lock" function similar
to how we handle this situation in other areas of the kernel.  We take
the lock of the socket pointer with the smallest address first in
order to avoid ABBA style deadlocks.

Once we have them both locked, we check to see if SOCK_DEAD is set
for 'other' and if so, drop everything and retry the lookup.
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      278a3de5