Two principals are involved in krb5 authentication: the target, who we
authenticate *to* (normally the name of the server, like
nfs/server.citi.umich.edu@CITI.UMICH.EDU), and the source, we we
authenticate *as* (normally a user, like bfields@UMICH.EDU)
In the case of NFSv4 callbacks, the target of the callback should be the
source of the client's setclientid call, and the source should be the
nfs server's own principal.
Therefore we allow svcgssd to pass down the name of the principal that
just authenticated, so that on setclientid we can store that principal
name with the new client, to be used later on callbacks.
Signed-off-by: Olga Kornievskaia <aglo@citi.umich.edu>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Implement the new upcall. We decide which version of the upcall gssd
will use (new or old), by creating both pipes (the new one named "gssd",
the old one named after the mechanism (e.g., "krb5")), and then waiting
to see which version gssd actually opens.
We don't permit pipes of the two different types to be opened at once.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Keep a pointer to the inode that the message is queued on in the struct
gss_upcall_msg. This will be convenient, especially after we have a
choice of two pipes that an upcall could be queued on.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Introduce a global variable pipe_version which will eventually be used
to keep track of which version of the upcall gssd is using.
For now, though, it only keeps track of whether any pipe is open or not;
it is negative if not, zero if one is opened. We use this to wait for
the first gssd to open a pipe.
(Minor digression: note this waits only for the very first open of any
pipe, not for the first open of a pipe for a given auth; thus we still
need the RPC_PIPE_WAIT_FOR_OPEN behavior to wait for gssd to open new
pipes that pop up on subsequent mounts.)
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Keep a count of the number of pipes open plus the number of messages on
a pipe. This count isn't used yet.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
I can't see any reason we need to call this until either the kernel or
the last gssd closes the pipe.
Also, this allows to guarantee that open_pipe and release_pipe are
called strictly in pairs; open_pipe on gssd's first open, release_pipe
on gssd's last close (or on the close of the kernel side of the pipe, if
that comes first).
That will make it very easy for the gss code to keep track of which
pipes gssd is using.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
We want to transition to a new gssd upcall which is text-based and more
easily extensible.
To simplify upgrades, as well as testing and debugging, it will help if
we can upgrade gssd (to a version which understands the new upcall)
without having to choose at boot (or module-load) time whether we want
the new or the old upcall.
We will do this by providing two different pipes: one named, as
currently, after the mechanism (normally "krb5"), and supporting the
old upcall. One named "gssd" and supporting the new upcall version.
We allow gssd to indicate which version it supports by its choice of
which pipe to open.
As we have no interest in supporting *simultaneous* use of both
versions, we'll forbid opening both pipes at the same time.
So, add a new pipe_open callback to the rpc_pipefs api, which the gss
code can use to track which pipes have been open, and to refuse opens of
incompatible pipes.
We only need this to be called on the first open of a given pipe.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
I want to add a little more code here, so it'll be convenient to have
this flatter.
Also, I'll want to add another error condition, so it'll be more
convenient to return -ENOMEM than NULL in the error case. The only
caller is already converting NULL to -ENOMEM anyway.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
We'll want to call this from elsewhere soon. And this is a bit nicer
anyway.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
We're just about to kfree() gss_auth, so there's no point to setting any
of its fields.
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
There's a bit of a chicken and egg problem when it comes to destroying
auth_gss credentials. When we destroy the last instance of a GSSAPI RPC
credential, we should send a NULL RPC call with a GSS procedure of
RPCSEC_GSS_DESTROY to hint to the server that it can destroy those
creds.
This isn't happening because we're setting clearing the uptodate bit on
the credentials and then setting the operations to the gss_nullops. When
we go to do the RPC call, we try to refresh the creds. That fails with
-EACCES and the call fails.
Fix this by not clearing the UPTODATE bit for the credentials and adding
a new crdestroy op for gss_nullops that just tears down the cred without
trying to destroy the context.
The only difference between this patch and the first one is the removal
of some minor formatting deltas.
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Hi.
I've been looking at a bugzilla which describes a problem where
a customer was advised to use either the "noac" or "actimeo=0"
mount options to solve a consistency problem that they were
seeing in the file attributes. It turned out that this solution
did not work reliably for them because sometimes, the local
attribute cache was believed to be valid and not timed out.
(With an attribute cache timeout of 0, the cache should always
appear to be timed out.)
In looking at this situation, it appears to me that the problem
is that the attribute cache timeout code has an off-by-one
error in it. It is assuming that the cache is valid in the
region, [read_cache_jiffies, read_cache_jiffies + attrtimeo]. The
cache should be considered valid only in the region,
[read_cache_jiffies, read_cache_jiffies + attrtimeo). With this
change, the options, "noac" and "actimeo=0", work as originally
expected.
This problem was previously addressed by special casing the
attrtimeo == 0 case. However, since the problem is only an off-
by-one error, the cleaner solution is address the off-by-one
error and thus, not require the special case.
Thanx...
ps
Signed-off-by: Peter Staubach <staubach@redhat.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
We've never considered the sunrpc code as part of any ABI to be used by
out-of-tree modules.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Somehow, this escaped the previous purge. There should be no need to keep
any extra locks in the XDR callbacks.
The NFS client XDR code only writes into private objects, whereas all reads
of shared objects are confined to fields that do not change, such as
filehandles...
Ditto for lockd, the NFSv2/v3 client mount code, and rpcbind.
The nfsd XDR code may require the BKL, but since it does a synchronous RPC
call from a thread that already holds the lock, that issue is moot.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6:
Phonet: keep TX queue disabled when the device is off
SCHED: netem: Correct documentation comment in code.
netfilter: update rwlock initialization for nat_table
netlabel: Compiler warning and NULL pointer dereference fix
e1000e: fix double release of mutex
IA64: HP_SIMETH needs to depend upon NET
netpoll: fix race on poll_list resulting in garbage entry
ipv6: silence log messages for locally generated multicast
sungem: improve ethtool output with internal pcs and serdes
tcp: tcp_vegas cong avoid fix
sungem: Make PCS PHY support partially work again.
The netem simulator is no longer limited by Linux timer resolution HZ.
Not since Patrick McHardy changed the QoS system to use hrtimer.
Signed-off-by: Jesper Dangaard Brouer <hawk@comx.dk>
Signed-off-by: David S. Miller <davem@davemloft.net>
The commit e099a17357
(netfilter: netns nat: per-netns NAT table) renamed the
nat_table from __nat_table to nat_table without updating the
__RW_LOCK_UNLOCKED(__nat_table.lock).
Signed-off-by: Steven Rostedt <srostedt@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Fix the two compiler warnings show below. Thanks to Geert Uytterhoeven for
finding and reporting the problem.
net/netlabel/netlabel_unlabeled.c:567: warning: 'entry' may be used
uninitialized in this function
net/netlabel/netlabel_unlabeled.c:629: warning: 'entry' may be used
uninitialized in this function
Signed-off-by: Paul Moore <paul.moore@hp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
A few months back a race was discused between the netpoll napi service
path, and the fast path through net_rx_action:
http://kerneltrap.org/mailarchive/linux-netdev/2007/10/16/345470
A patch was submitted for that bug, but I think we missed a case.
Consider the following scenario:
INITIAL STATE
CPU0 has one napi_struct A on its poll_list
CPU1 is calling netpoll_send_skb and needs to call poll_napi on the same
napi_struct A that CPU0 has on its list
CPU0 CPU1
net_rx_action poll_napi
!list_empty (returns true) locks poll_lock for A
poll_one_napi
napi->poll
netif_rx_complete
__napi_complete
(removes A from poll_list)
list_entry(list->next)
In the above scenario, net_rx_action assumes that the per-cpu poll_list is
exclusive to that cpu. netpoll of course violates that, and because the netpoll
path can dequeue from the poll list, its possible for CPU0 to detect a non-empty
list at the top of the while loop in net_rx_action, but have it become empty by
the time it calls list_entry. Since the poll_list isn't surrounded by any other
structure, the returned data from that list_entry call in this situation is
garbage, and any number of crashes can result based on what exactly that garbage
is.
Given that its not fasible for performance reasons to place exclusive locks
arround each cpus poll list to provide that mutal exclusion, I think the best
solution is modify the netpoll path in such a way that we continue to guarantee
that the poll_list for a cpu is in fact exclusive to that cpu. To do this I've
implemented the patch below. It adds an additional bit to the state field in
the napi_struct. When executing napi->poll from the netpoll_path, this bit will
be set. When a driver calls netif_rx_complete, if that bit is set, it will not
remove the napi_struct from the poll_list. That work will be saved for the next
iteration of net_rx_action.
I've tested this and it seems to work well. About the biggest drawback I can
see to it is the fact that it might result in an extra loop through
net_rx_action in the event that the device is actually contended for (i.e. the
netpoll path actually preforms all the needed work no the device, and the call
to net_rx_action winds up doing nothing, except removing the napi_struct from
the poll_list. However I think this is probably a small price to pay, given
that the alternative is a crash.
Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch fixes minor annoyance during transmission of unsolicited
neighbor advertisements from userspace to multicast addresses (as
far as I can see in RFC, this is allowed and the similar functionality
for IPv4 has been in arping for a long time).
Outgoing multicast packets get reinserted into local processing as if they
are received from the network. The machine thus sees its own NA and fills
the logs with error messages. This patch removes the message if NA has been
generated locally.
Signed-off-by: Jan Sembera <jsembera@suse.cz>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch addresses a book-keeping issue in tcp_vegas.c. At present
tcp_vegas does separate book-keeping of cwnd based on packet sequence
numbers. A mismatch can develop between this book-keeping and
tp->snd_cwnd due, for example, to delayed acks acking multiple
packets. When vegas transitions to reno operation (e.g. following
loss), then this mismatch leads to incorrect behaviour (akin to a cwnd
backoff). This seems mostly to affect operation at low cwnds where
delayed acking can lead to a significant fraction of cwnd being
covered by a single ack, leading to the book-keeping mismatch. This
patch modifies the congestion avoidance update to avoid the need for
separate book-keeping while leaving vegas congestion avoidance
functionally unchanged. A secondary advantage of this modification is
that the use of fixed-point (via V_PARAM_SHIFT) and 64 bit arithmetic
is no longer necessary, simplifying the code.
Some example test measurements with the patched code (confirming no functional
change in the congestion avoidance algorithm) can be seen at:
http://www.hamilton.ie/doug/vegaspatch/
Signed-off-by: Doug Leith <doug.leith@nuim.ie>
Signed-off-by: David S. Miller <davem@davemloft.net>
* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-2.6:
tproxy: fixe a possible read from an invalid location in the socket match
zd1211rw: use unaligned safe memcmp() in-place of compare_ether_addr()
mac80211: use unaligned safe memcmp() in-place of compare_ether_addr()
ipw2200: fix netif_*_queue() removal regression
iwlwifi: clean key table in iwl_clear_stations_table function
tcp: tcp_vegas ssthresh bug fix
can: omit received RTR frames for single ID filter lists
ATM: CVE-2008-5079: duplicate listen() on socket corrupts the vcc table
netx-eth: initialize per device spinlock
tcp: make urg+gso work for real this time
enc28j60: Fix sporadic packet loss (corrected again)
hysdn: fix writing outside the field on 64 bits
b1isa: fix b1isa_exit() to really remove registered capi controllers
can: Fix CAN_(EFF|RTR)_FLAG handling in can_filter
Phonet: do not dump addresses from other namespaces
netlabel: Fix a potential NULL pointer dereference
bnx2: Add workaround to handle missed MSI.
xfrm: Fix kernel panic when flush and dump SPD entries
TIME_WAIT sockets need to be handled specially, and the socket match
casted inet_timewait_sock instances to inet_sock, which are not
compatible.
Handle this special case by checking sk->sk_state.
Signed-off-by: Balazs Scheidler <bazsi@balabit.hu>
Signed-off-by: David S. Miller <davem@davemloft.net>
After fixing zd1211rw: use unaligned safe memcmp() in-place of
compare_ether_addr(), I started to see kernel log messages detailing
unaligned access:
Kernel unaligned access at TPC[100f7f44] sta_info_get+0x24/0x68 [mac80211]
As with the aforementioned patch, the unaligned access was eminating
from a compare_ether_addr() call. Concerned that whilst it was safe to
assume that unalignment was the norm for the zd1211rw, and take
preventative measures, it may not be the case or acceptable to use the
easy fix of changing the call to memcmp().
My research however indicated that it was OK to do this, as there are
a few instances where memcmp() is the preferred mechanism for doing
mac address comparisons throughout the module.
Signed-off-by: Shaddy Baddah <shaddy_baddah@hotmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
This patch fixes a bug in tcp_vegas.c. At the moment this code leaves
ssthresh untouched. However, this means that the vegas congestion
control algorithm is effectively unable to reduce cwnd below the
ssthresh value (if the vegas update lowers the cwnd below ssthresh,
then slow start is activated to raise it back up). One example where
this matters is when during slow start cwnd overshoots the link
capacity and a flow then exits slow start with ssthresh set to a value
above where congestion avoidance would like to adjust it.
Signed-off-by: Doug Leith <doug.leith@nuim.ie>
Signed-off-by: David S. Miller <davem@davemloft.net>
Since commit d253eee201 the single CAN
identifier filter lists handle only non-RTR CAN frames.
So we need to omit the check of these filter lists when receiving RTR
CAN frames.
Signed-off-by: Oliver Hartkopp <oliver@hartkopp.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
As reported by Hugo Dias that it is possible to cause a local denial
of service attack by calling the svc_listen function twice on the same
socket and reading /proc/net/atm/*vc
Signed-off-by: Chas Williams <chas@cmf.nrl.navy.mil>
Signed-off-by: David S. Miller <davem@davemloft.net>
I should have noticed this earlier... :-) The previous solution
to URG+GSO/TSO will cause SACK block tcp_fragment to do zig-zig
patterns, or even worse, a steep downward slope into packet
counting because each skb pcount would be truncated to pcount
of 2 and then the following fragments of the later portion would
restore the window again.
Basically this reverts "tcp: Do not use TSO/GSO when there is
urgent data" (33cf71cee1). It also removes some unnecessary code
from tcp_current_mss that didn't work as intented either (could
be that something was changed down the road, or it might have
been broken since the dawn of time) because it only works once
urg is already written while this bug shows up starting from
~64k before the urg point.
The retransmissions already are split to mss sized chunks, so
only new data sending paths need splitting in case they have
a segment otherwise suitable for gso/tso. The actually check
can be improved to be more narrow but since this is late -rc
already, I'll postpone thinking the more fine-grained things.
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@helsinki.fi>
Signed-off-by: David S. Miller <davem@davemloft.net>
* 'for-2.6.28' of git://linux-nfs.org/~bfields/linux:
NLM: client-side nlm_lookup_host() should avoid matching on srcaddr
nfsd: use of unitialized list head on error exit in nfs4recover.c
Add a reference to sunrpc in svc_addsock
nfsd: clean up grace period on early exit
Due to a wrong safety check in af_can.c it was not possible to filter
for SFF frames with a specific CAN identifier without getting the
same selected CAN identifier from a received EFF frame also.
This fix has a minimum (but user visible) impact on the CAN filter
API and therefore the CAN version is set to a new date.
Indeed the 'old' API is still working as-is. But when now setting
CAN_(EFF|RTR)_FLAG in can_filter.can_mask you might get less traffic
than before - but still the stuff that you expected to get for your
defined filter ...
Thanks to Kurt Van Dijck for pointing at this issue and for the review.
Signed-off-by: Oliver Hartkopp <oliver@hartkopp.net>
Acked-by: Kurt Van Dijck <kurt.van.dijck@eia.be>
Signed-off-by: David S. Miller <davem@davemloft.net>
Fix a potential NULL pointer dereference seen when trying to remove a
static label configuration with an invalid address/mask combination.
Signed-off-by: Paul Moore <paul.moore@hp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
After flush the SPD entries, dump the SPD entries will cause kernel painc.
Used the following commands to reproduct:
- echo 'spdflush;' | setkey -c
- echo 'spdadd 3ffe:501:ffff:ff01::/64 3ffe:501:ffff:ff04::/64 any -P out ipsec \
ah/tunnel/3ffe:501:ffff:ff00:200:ff:fe00:b0b0-3ffe:501:ffff:ff02:200:ff:fe00:a1a1/require;\
spddump;' | setkey -c
- echo 'spdflush; spddump;' | setkey -c
- echo 'spdadd 3ffe:501:ffff:ff01::/64 3ffe:501:ffff:ff04::/64 any -P out ipsec \
ah/tunnel/3ffe:501:ffff:ff00:200:ff:fe00:b0b0-3ffe:501:ffff:ff02:200:ff:fe00:a1a1/require;\
spddump;' | setkey -c
This is because when flush the SPD entries, the SPD entry is not remove
from the list.
This patch fix the problem by remove the SPD entry from the list.
Signed-off-by: Wei Yongjun <yjwei@cn.fujitsu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This is an implementation of David Miller's suggested fix in:
https://bugzilla.redhat.com/show_bug.cgi?id=470201
It has been updated to use wait_event() instead of
wait_event_interruptible().
Paraphrasing the description from the above report, it makes sendmsg()
block while UNIX garbage collection is in progress. This avoids a
situation where child processes continue to queue new FDs over a
AF_UNIX socket to a parent which is in the exit path and running
garbage collection on these FDs. This contention can result in soft
lockups and oom-killing of unrelated processes.
Signed-off-by: dann frazier <dannf@hp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
A NULL dereference would occur when trying to delete an addres from a
network device that does not have any Phonet address.
Signed-off-by: Rémi Denis-Courmont <remi.denis-courmont@nokia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The previous fix for the conntrack creation race (netfilter: ctnetlink:
fix conntrack creation race) missed a GFP_KERNEL allocation that is
now performed while holding a spinlock. Switch to GFP_ATOMIC.
Reported-and-tested-by: Zoltan Borbely <bozo@andrews.hu>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
The truesize message check is important enough to make it print "BUG"
to the user console... lets also make it important enough to spit a
backtrace/module list etc so that kerneloops.org can track them.
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
fix:
net/wireless/reg.c:348:29: error: macro "if" passed 2 arguments, but takes just 1
triggered by the branch-tracer.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Patch fixes the kernel trace when user tries to set
ad-hoc mode on non IBSS channel.
e.g iwconfig wlan0 chan 36 mode ad-hoc
Signed-off-by: Abhijeet Kolekar <abhijeet.kolekar@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Since changeset e79ad711a0 from mainline,
>From David S. Miller,
empty packet can be transmitted on connected socket for datagram protocols.
However, this patch broke a high level application using ROSE network protocol with connected datagram.
Bulletin Board Stations perform bulletins forwarding between BBS stations via ROSE network using a forward protocol.
Now, if for some reason, a buffer in the application software happens to be empty at a specific moment,
ROSE sends an empty packet via unfiltered packet socket.
When received, this ROSE packet introduces perturbations of data exchange of BBS forwarding,
for the application message forwarding protocol is waiting for something else.
We agree that a more careful programming of the application protocol would avoid this situation and we are
willing to debug it.
But, as an empty frame is no use and does not have any meaning for ROSE protocol,
we may consider filtering zero length data both when sending and receiving socket data.
The proposed patch repaired BBS data exchange through ROSE network that were broken since 2.6.22.11 kernel.
Signed-off-by: Bernard Pidoux <f6bvp@amsat.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
As GRE tries to call the update_pmtu function on skb->dst and
bridge supplies an skb->dst that has a NULL ops field, all is
not well.
This patch fixes this by giving the bridge device an ops field
with an update_pmtu function. For the moment I've left all
other fields blank but we can fill them in later should the
need arise.
Based on report and patch by Philip Craig.
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
Conntrack creation through ctnetlink has two races:
- the timer may expire and free the conntrack concurrently, causing an
invalid memory access when attempting to put it in the hash tables
- an identical conntrack entry may be created in the packet processing
path in the time between the lookup and hash insertion
Hold the conntrack lock between the lookup and insertion to avoid this.
Reported-by: Zoltan Borbely <bozo@andrews.hu>
Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>
The svc_addsock function adds transport instances without taking a
reference on the sunrpc.ko module, however, the generic transport
destruction code drops a reference when a transport instance
is destroyed.
Add a try_module_get call to the svc_addsock function for transport
instances added by this function.
Signed-off-by: Tom Tucker <tom@opengridcomputing.com>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Tested-by: Jeff Moyer <jmoyer@redhat.com>
If the slub allocator is used, kmem_cache_create() may merge two or more
kmem_cache's into one but the cache name pointer is not updated and
kmem_cache_name() is no longer guaranteed to return the pointer passed
to the former function. This patch stores the kmalloc'ed pointers in the
corresponding request_sock_ops and timewait_sock_ops structures.
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Reviewed-by: Christoph Lameter <cl@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
This patch fixes http://bugzilla.kernel.org/show_bug.cgi?id=12014
Since most (if not all) implementations of TSO and even the in-kernel
software GSO do not update the urgent pointer when splitting a large
segment, it is necessary to turn off TSO/GSO for all outgoing traffic
with the URG pointer set.
Looking at tcp_current_mss (and the preceding comment) I even think
this was the original intention. However, this approach is insufficient,
because TSO/GSO is turned off only for newly created frames, not for
frames which were already pending at the arrival of a message with
MSG_OOB set. These frames were created when TSO/GSO was enabled,
so they may be large, and they will have the urgent pointer set
in tcp_transmit_skb().
With this patch, such large packets will be fragmented again before
going to the transmit routine.
As a side note, at least the following NICs are known to screw up
the urgent pointer in the TCP header when doing TSO:
Intel 82566MM (PCI ID 8086:1049)
Intel 82566DC (PCI ID 8086:104b)
Intel 82541GI (PCI ID 8086:1076)
Broadcom NetXtreme II BCM5708 (PCI ID 14e4:164c)
Signed-off-by: Petr Tesarik <ptesarik@suse.cz>
Signed-off-by: David S. Miller <davem@davemloft.net>
Fix a regression reported by Max Kellermann whereby kernel profiling
showed that his clients were spending 45% of their time in
rpcauth_lookup_credcache.
It turns out that although his processes had identical uid/gid/groups,
generic_match() was failing to detect this, because the task->group_info
pointers were not shared. This again lead to the creation of a huge number
of identical credentials at the RPC layer.
The regression is fixed by comparing the contents of task->group_info
if the actual pointers are not identical.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
