the first microbenchmark does
fd=open("/proc/self/comm");
for() {
  write(fd, "test");
}
and on 4 cpus in parallel:
                                      writes per sec
base (no tracepoints, no kprobes)         930k
with kprobe at __set_task_comm()          420k
with tracepoint at task:task_rename       730k

For kprobe + full bpf program manully fetches oldcomm, newcomm via bpf_probe_read.
For tracepint bpf program does nothing, since arguments are copied by tracepoint.

2nd microbenchmark does:
fd=open("/dev/urandom");
for() {
  read(fd, buf);
}
and on 4 cpus in parallel:
                                       reads per sec
base (no tracepoints, no kprobes)         300k
with kprobe at urandom_read()             279k
with tracepoint at random:urandom_read    290k

bpf progs attached to kprobe and tracepoint are noop.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

modify offwaketime to work with sched/sched_switch tracepoint
instead of kprobe into finish_task_switch
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Recognize "tracepoint/" section name prefix and attach the program
to that tracepoint.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

during bpf program loading remember the last byte of ctx access
and at the time of attaching the program to tracepoint check that
the program doesn't access bytes beyond defined in tracepoint fields

This also disallows access to __dynamic_array fields, but can be
relaxed in the future.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

needs two wrapper functions to fetch 'struct pt_regs *' to convert
tracepoint bpf context into kprobe bpf context to reuse existing
helper functions
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

register tracepoint bpf program type and let it call the same set
of helper functions as BPF_PROG_TYPE_KPROBE
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

introduce BPF_PROG_TYPE_TRACEPOINT program type and allow it to be attached
to the perf tracepoint handler, which will copy the arguments into
the per-cpu buffer and pass it to the bpf program as its first argument.
The layout of the fields can be discovered by doing
'cat /sys/kernel/debug/tracing/events/sched/sched_switch/format'
prior to the compilation of the program with exception that first 8 bytes
are reserved and not accessible to the program. This area is used to store
the pointer to 'struct pt_regs' which some of the bpf helpers will use:
+---------+
| 8 bytes | hidden 'struct pt_regs *' (inaccessible to bpf program)
+---------+
| N bytes | static tracepoint fields defined in tracepoint/format (bpf readonly)
+---------+
| dynamic | __dynamic_array bytes of tracepoint (inaccessible to bpf yet)
+---------+

Not that all of the fields are already dumped to user space via perf ring buffer
and broken application access it directly without consulting tracepoint/format.
Same rule applies here: static tracepoint fields should only be accessed
in a format defined in tracepoint/format. The order of fields and
field sizes are not an ABI.
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

split allows to move expensive update of 'struct trace_entry' to later phase.
Repurpose unused 1st argument of perf_tp_event() to indicate event type.

While splitting use temp variable 'rctx' instead of '*rctx' to avoid
unnecessary loads done by the compiler due to -fno-strict-aliasing
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

now all calls to perf_trace_buf_submit() pass 0 as 4th
argument which will be repurposed in the next patch which will
change the meaning of 1st arg of perf_tp_event() to event_type
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

avoid memset in perf_fetch_caller_regs, since it's the critical path of all tracepoints.
It's called from perf_sw_event_sched, perf_event_task_sched_in and all of perf_trace_##call
with this_cpu_ptr(&__perf_regs[..]) which are zero initialized by perpcu init logic and
subsequent call to perf_arch_fetch_caller_regs initializes the same fields on all archs,
so we can safely drop memset from all of the above cases and move it into
perf_ftrace_function_call that calls it with stack allocated pt_regs.
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Needs to be protected with CONFIG_LOCKDEP.

Based upon a patch by Hannes Frederic Sowa.
Signed-off-by: David S. Miller <davem@davemloft.net>

I forgot to add inline to lockdep_sock_is_held, so it generated all
kinds of build warnings if not build with lockdep support.
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

Jon Maloy says:

====================
tipc: some small fixes

When fix a minor buffer leak, and ensure that bearers filter packets
correctly while they are being shut down.

v2: Corrected typos in commit #3, as per feedback from S. Shtylyov
v3: Removed commit #3 from the series. Improved version will be
    re-submitted later.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Resetting a bearer/interface, with the consequence of resetting all its
pertaining links, is not an atomic action. This becomes particularly
evident in very large clusters, where a lot of traffic may happen on the
remaining links while we are busy shutting them down. In extreme cases,
we may even see links being re-created and re-established before we are
finished with the job.

To solve this, we now introduce a solution where we temporarily detach
the bearer from the interface when the bearer is reset. This inhibits
all packet reception, while sending still is possible. For the latter,
we use the fact that the device's user pointer now is zero to filter out
which packets can be sent during this situation; i.e., outgoing RESET
messages only.  This filtering serves to speed up the neighbors'
detection of the loss event, and saves us from unnecessary probing.
Acked-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

When enabling a bearer we create a 'neigbor discoverer' instance by
calling the function tipc_disc_create() before the bearer is actually
registered in the list of enabled bearers. Because of this, the very
first discovery broadcast message, created by the mentioned function,
is lost, since it cannot find any valid bearer to use. Furthermore,
the used send function, tipc_bearer_xmit_skb() does not free the given
buffer when it cannot find a  bearer, resulting in the leak of exactly
one send buffer each time a bearer is enabled.

This commit fixes this problem by introducing two changes:

1) Instead of attemting to send the discovery message directly, we let
   tipc_disc_create() return the discovery buffer to the calling
   function, tipc_enable_bearer(), so that the latter can send it
   when the enabling sequence is finished.

2) In tipc_bearer_xmit_skb(), as well as in the two other transmit
   functions at the bearer layer, we now free the indicated buffer or
   buffer chain when a valid bearer cannot be found.
Acked-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: Jon Maloy <jon.maloy@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Tom Herbert says:

====================
udp: GRO in UDP sockets

This patch set adds GRO functions (gro_receive and gro_complete) to UDP
sockets and removes udp_offload infrastructure.

Add GRO functions (gro_receive and gro_complete) to UDP sockets. In
udp_gro_receive and udp_gro_complete a socket lookup is done instead of
looking up the port number in udp_offloads.  If a socket is found and
there are GRO functions for it then those are called. This feature
allows binding GRO functions to more than just a port number.
Eventually, we will be able to use this technique to allow application
defined GRO for an application protocol by attaching BPF porgrams to UDP
sockets for doing GRO.

In order to implement these functions, we added exported
udp6_lib_lookup_skb and udp4_lib_lookup_skb functions in ipv4/udp.c and
ipv6/udp.c. Also, inet_iif and references to skb_dst() were changed to
check that dst is set in skbuf before derefencing. In the GRO path there
is now a UDP socket lookup performed before dst is set, to the get the
device in that case we simply use skb->dev.

Tested:

Ran various combinations of VXLAN and GUE TCP_STREAM and TCP_RR tests.
Did not see any material regression.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Now that the UDP encapsulation GRO functions have been moved to the UDP
socket we not longer need the udp_offload insfrastructure so removing it.
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Adapt geneve_gro_receive, geneve_gro_complete to take a socket argument.
Set these functions in tunnel_config.  Don't set udp_offloads any more.
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Adapt gue_gro_receive, gue_gro_complete to take a socket argument.
Don't set udp_offloads any more.
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Adapt vxlan_gro_receive, vxlan_gro_complete to take a socket argument.
Set these functions in tunnel_config.  Don't set udp_offloads any more.
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Add gro_receive and  gro_complete to struct udp_tunnel_sock_cfg.
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This patch adds GRO functions (gro_receive and gro_complete) to UDP
sockets. udp_gro_receive is changed to perform socket lookup on a
packet. If a socket is found the related GRO functions are called.

This features obsoletes using UDP offload infrastructure for GRO
(udp_offload). This has the advantage of not being limited to provide
offload on a per port basis, GRO is now applied to whatever individual
UDP sockets are bound to.  This also allows the possbility of
"application defined GRO"-- that is we can attach something like
a BPF program to a UDP socket to perfrom GRO on an application
layer protocol.
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Add externally visible functions to lookup a UDP socket by skb. This
will be used for GRO in UDP sockets. These functions also check
if skb->dst is set, and if it is not skb->dev is used to get dev_net.
This allows calling lookup functions before dst has been set on the
skbuff.
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

In inet_iif check if skb_rtable is NULL for the skb and return
skb->skb_iif if it is.

This change allows inet_iif to be called before the dst
information has been set in the skb (e.g. when doing socket based
UDP GRO).
Signed-off-by: Tom Herbert <tom@herbertland.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Hannes Frederic Sowa says:

====================
sock: lockdep tightening

First patch is from Eric Dumazet and improves lockdep accuracy for
socket locks. After that, second patch introduces lockdep_sock_is_held
and uses it. Final patch reverts and reworks the lockdep fix from Daniel
in the filter code, as we now have tighter lockdep support.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

This reverts commit 5a5abb1f ("tun, bpf: fix suspicious RCU usage
in tun_{attach, detach}_filter") and replaces it to use lock_sock around
sk_{attach,detach}_filter. The checks inside filter.c are updated with
lockdep_sock_is_held to check for proper socket locks.

It keeps the code cleaner by ensuring that only one lock governs the
socket filter instead of two independent locks.

Cc: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

The socket is either locked if we hold the slock spin_lock for
lock_sock_fast and unlock_sock_fast or we own the lock (sk_lock.owned
!= 0). Check for this and at the same time improve that the current
thread/cpu is really holding the lock.
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

During release_sock we use callbacks to finish the processing
of outstanding skbs on the socket. We actually are still locked,
sk_locked.owned == 1, but we already told lockdep that the mutex
is released. This could lead to false positives in lockdep for
lockdep_sock_is_held (we don't hold the slock spinlock during processing
the outstanding skbs).

I took over this patch from Eric Dumazet and tested it.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

David Ahern reported panics in __inet_hash() caused by my recent commit.

The reason is inet_reuseport_add_sock() was still using
sk_nulls_for_each_rcu() instead of sk_for_each_rcu().
SO_REUSEPORT enabled listeners were causing an instant crash.

While chasing this bug, I found that I forgot to clear SOCK_RCU_FREE
flag, as it is inherited from the parent at clone time.

Fixes: 3b24d854 ("tcp/dccp: do not touch listener sk_refcnt under synflood")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: David Ahern <dsa@cumulusnetworks.com>
Tested-by: David Ahern <dsa@cumulusnetworks.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Jeff Kirsher says:

====================
1GbE Intel Wired LAN Driver Updates 2016-04-06

This series contains updates to e1000, e1000e, igb and Kconfig.

Alex fixes igb where we were casting the MAC address as __beXX and then
passing it into le32_to_cpu, when we could simply cast as __lexx to
maintain consistency since it is already little endian.  Then enabled
bulk free in transmit cleanup for igb.

John Holland enables igb to pickup the MAC address from a device tree
blob when CONFIG_OF has been enabled.

Doron Shikmoni fixes a bug in the output of "ethtool -m ethX" where
the data byte appeared duplicated.

Stefan fixes up e1000 and e1000e ethtool offline tests which were calling
dev_close() which causes IFF_UP to be cleared which removes teh interface
routes and some addresses, so use ndo_stop() instead.

Jiri Benc cleans up some old links in the Kconfig for Intel drivers where
we referred to a URL which is no longer valid.  I am so glad Jiri has the
time in his day to spend clicking on and testing all the URL links in the
the kernel.

Arika Chen reverts the addition of a 'rtnl_unlock()' which had a unmatched
'rtnl_lock()' call before it.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Jeff Kirsher says:

====================
40GbE Intel Wired LAN Driver Updates 2016-04-06

This series contains updates to i40e and i40evf.

Deepthi adds a debug message to display the MSIx vector count for hardware
capabilities.

Shannon removed the setting of debug_mask at startup to take care of an
issue where all the device capabilities getting printed when we had not
asked for it.  Moved the NVM status out of the admin queue structure,
since it should really stay with the other NVM data structures.

Akeem added the flush routine to the end of the reset flow to avoid
problems in the pass-through routines.

Jesse moves a local variable deeper into the depths of the driver
where the light is low and the context is great.  Then cleaned up
the tx_ring argument since it was not making good arguments.  Improved
performance by not "checking for FCoE" by re-ordering the FCoE checks.

Anjali adds the support for changing a VF from non-trusted to trusted
and vice-versa.

Mitch adds opcodes and structures to support RSS configuration by PF
driver on behalf of the VF driver.  Fixed how the VLAN feature flags
are set.

Kiran added defines for RSS, flow director, flexible payload and IPv6.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

This reverts commit 3eb14ea8 ("igb: Fix a deadlock in
igb_sriov_reinit")
It is the same as commit f468adc9 ("igb: missing rtnl_unlock in
igb_sriov_reinit()")
There is no rtnl_lock() in igb_resume before, rtnl_unlock will cause a
deadlock.
Signed-off-by: Arika Chen <arika.chen@huawei.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

The Kconfig for Intel NICs references two different URLs for the "Adapter
& Driver ID Guide". Neither of those two links works. The current URL seems
to be
http://www.intel.com/content/www/us/en/support/network-and-i-o/ethernet-products/000005584.html
but given it's apparently constantly changing, there's no point in having it
in the help text.

Just keep a generic pointer to http://support.intel.com. Hopefully, this one
will have a longer live. It still works, at least.

Furthermore, remove a link to "the latest Intel PRO/100 network driver for
Linux", this has no place in the mainline kernel and the latest Linux driver
it offers is from 2006, anyway.
Signed-off-by: Jiri Benc <jbenc@redhat.com>
Tested-by: Aaron Brown <aaron.f.brown@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

Correctly set the VLAN feature flags after setting the rest of the
netdev flags. And don't set them in hw_features, because these can't be
controlled by the VF driver.
Signed-off-by: Mitch Williams <mitch.a.williams@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

Signed-off-by: Harshitha Ramamurthy <harshitha.ramamurthy@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

Add defines for input set mask (RSS, flow director, flexible payload),
including defines specific to IPv6.

Change-ID: Ie95ef7d0916a4d6ca011c194283f959774c8dce9
Signed-off-by: Kiran Patil <kiran.patil@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

The logic that checks AQ events for NVM done events is better kept
in nvm.c with the rest of the nvmupdate handling code.

Change-ID: I2ea58980df8ecaa3726b28a37bff3dfcb8df03dc
Signed-off-by: Shannon Nelson <shannon.nelson@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

Add opcodes and structures to support RSS configuration by PF driver on
behalf of the VF drivers. This reduces complexity in the VF driver and
allows us to support future hardware designs without modifying the VF
driver.

Change-ID: I8c75765c630eacb71f95967f1109a198542593ac
Signed-off-by: Mitch Williams <mitch.a.williams@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

The NVM update status info should stay collected together, not
spread across different structs.

Change-ID: Ic16f9e9fd79945d865bb7226184c889884585025
Signed-off-by: Shannon Nelson <shannon.nelson@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>

The VFs can request their queues to be set up into polling mode, rather
than interrupt mode, which works well for supporting things like DPDK,
but this should not be available when working in an multi-function
support device.

Change-ID: Id36792e4e7422db8f2033336507211f68f14ff6f
Signed-off-by: Shannon Nelson <shannon.nelson@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>