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  1. 12 6月, 2006 1 次提交
  3. 06 5月, 2006 1 次提交
    • H
      [DCCP]: Fix sock_orphan dead lock · 134af346
      由 Herbert Xu 提交于 
      Calling sock_orphan inside bh_lock_sock in dccp_close can lead to dead
locks.  For example, the inet_diag code holds sk_callback_lock without
disabling BH.  If an inbound packet arrives during that admittedly tiny
window, it will cause a dead lock on bh_lock_sock.  Another possible
path would be through sock_wfree if the network device driver frees the
tx skb in process context with BH enabled.

We can fix this by moving sock_orphan out of bh_lock_sock.

The tricky bit is to work out when we need to destroy the socket
ourselves and when it has already been destroyed by someone else.

By moving sock_orphan before the release_sock we can solve this
problem.  This is because as long as we own the socket lock its
state cannot change.

So we simply record the socket state before the release_sock
and then check the state again after we regain the socket lock.
If the socket state has transitioned to DCCP_CLOSED in the time being,
we know that the socket has been destroyed.  Otherwise the socket is
still ours to keep.

This problem was discoverd by Ingo Molnar using his lock validator.
Signed-off-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      134af346
  5. 12 4月, 2006 1 次提交
  7. 30 3月, 2006 1 次提交
  9. 26 3月, 2006 1 次提交
    • D
      [PATCH] POLLRDHUP/EPOLLRDHUP handling for half-closed devices notifications · f348d70a
      由 Davide Libenzi 提交于 
      Implement the half-closed devices notifiation, by adding a new POLLRDHUP
(and its alias EPOLLRDHUP) bit to the existing poll/select sets.  Since the
existing POLLHUP handling, that does not report correctly half-closed
devices, was feared to be changed, this implementation leaves the current
POLLHUP reporting unchanged and simply add a new bit that is set in the few
places where it makes sense.  The same thing was discussed and conceptually
agreed quite some time ago:

http://lkml.org/lkml/2003/7/12/116

Since this new event bit is added to the existing Linux poll infrastruture,
even the existing poll/select system calls will be able to use it.  As far
as the existing POLLHUP handling, the patch leaves it as is.  The
pollrdhup-2.6.16.rc5-0.10.diff defines the POLLRDHUP for all the existing
archs and sets the bit in the six relevant files.  The other attached diff
is the simple change required to sys/epoll.h to add the EPOLLRDHUP
definition.

There is "a stupid program" to test POLLRDHUP delivery here:

 http://www.xmailserver.org/pollrdhup-test.c

It tests poll(2), but since the delivery is same epoll(2) will work equally.
Signed-off-by: NDavide Libenzi <davidel@xmailserver.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Michael Kerrisk <mtk-manpages@gmx.net>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>
      f348d70a
  11. 21 3月, 2006 35 次提交