rt6_remove_exception_rt() is called under rcu_read_lock() only.

We lock rt6_exception_lock a bit later, so we do not hold
rt6_exception_lock yet.

Fixes: 8a14e46f ("net/ipv6: Fix missing rcu dereferences on from")
Signed-off-by: NEric Dumazet <edumazet@google.com>
Reported-by: Nsyzbot <syzkaller@googlegroups.com>
Cc: David Ahern <dsahern@gmail.com>
Acked-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

A duplicated null check on sgout is redundant as it is known to be
already true because of the identical earlier check. Remove it.
Detected by cppcheck:

net/tls/tls_sw.c:696: (warning) Identical inner 'if' condition is always
true.
Signed-off-by: NColin Ian King <colin.king@canonical.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The check port->rev_info.major >= 6 is being performed twice, thus
the inner second check is always true and is redundant, hence it
can be removed. Detected by cppcheck.

drivers/net/ethernet/freescale/fman/fman_port.c:1394]: (warning)
Identical inner 'if' condition is always true.
Signed-off-by: NColin Ian King <colin.king@canonical.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The strscpy() was a recent fix (net: qed: use correct strncpy() size) to
prevent passing the length of the source buffer to strncpy() and guarantee
null termination.
It misses the goal of overwriting only the first 3 characters in
"???_BIG_RAM" and "???_RAM" while keeping the rest of the string.
Use strncpy() with the length of 3, without null termination.
Signed-off-by: NDenis Bolotin <denis.bolotin@cavium.com>
Signed-off-by: NAriel Elior <ariel.elior@cavium.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Chris Novakovic says:

====================
ipconfig: NTP server support, bug fixes, documentation improvements

This series (against net-next) makes various improvements to ipconfig:

 - Patch #1 correctly documents the behaviour of parameter 4 in the
   "ip=" and "nfsaddrs=" command line parameter.
 - Patch #2 tidies up the printk()s for reporting configured name
   servers.
 - Patch #3 fixes a bug in autoconfiguration via BOOTP whereby the IP
   addresses of IEN-116 name servers are requested from the BOOTP
   server, rather than those of DNS name servers.
 - Patch #4 requests the number of DNS servers specified by
   CONF_NAMESERVERS_MAX when autoconfiguring via BOOTP, rather than
   hardcoding it to 2.
 - Patch #5 fully documents the contents and format of /proc/net/pnp in
   Documentation/filesystems/nfs/nfsroot.txt.
 - Patch #6 fixes a bug whereby bogus information is written to
   /proc/net/pnp when ipconfig is not used.
 - Patch #7 creates a new procfs directory for ipconfig-related
   configuration reports at /proc/net/ipconfig.
 - Patch #8 allows for NTP servers to be configured (manually on the
   kernel command line or automatically via DHCP), enabling systems with
   an NFS root filesystem to synchronise their clock before mounting
   their root filesystem. NTP server IP addresses are written to
   /proc/net/ipconfig/ntp_servers.

Changes from v1:

 - David requested that a new directory /proc/net/ipconfig be created to
   contain ipconfig-related configuration reports, which is implemented
   in the new patch #7. NTP server IPs are now written to this directory
   instead of /proc/net/ntp in the new patch #8.
 - Cong and David both requested that the modification to CREDITS be
   dropped. This patch has been removed from the series.
====================
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Distributed filesystems are most effective when the server and client
clocks are synchronised. Embedded devices often use NFS for their
root filesystem but typically do not contain an RTC, so the clocks of
the NFS server and the embedded device will be out-of-sync when the root
filesystem is mounted (and may not be synchronised until late in the
boot process).

Extend ipconfig with the ability to export IP addresses of NTP servers
it discovers to /proc/net/ipconfig/ntp_servers. They can be supplied as
follows:

 - If ipconfig is configured manually via the "ip=" or "nfsaddrs="
   kernel command line parameters, one NTP server can be specified in
   the new "<ntp0-ip>" parameter.
 - If ipconfig is autoconfigured via DHCP, request DHCP option 42 in
   the DHCPDISCOVER message, and record the IP addresses of up to three
   NTP servers sent by the responding DHCP server in the subsequent
   DHCPOFFER message.

ipconfig will only write the NTP server IP addresses it discovers to
/proc/net/ipconfig/ntp_servers, one per line (in the order received from
the DHCP server, if DHCP autoconfiguration is used); making use of these
NTP servers is the responsibility of a user space process (e.g. an
initrd/initram script that invokes an NTP client before mounting an NFS
root filesystem).
Signed-off-by: NChris Novakovic <chris@chrisn.me.uk>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

To allow ipconfig to report IP configuration details to user space
processes without cluttering /proc/net, create a new subdirectory
/proc/net/ipconfig. All files containing IP configuration details should
be written to this directory.
Signed-off-by: NChris Novakovic <chris@chrisn.me.uk>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

ic_nameservers, which stores the list of name servers discovered by
ipconfig, is initialised (i.e. has all of its elements set to NONE, or
0xffffffff) by ic_nameservers_predef() in the following scenarios:

 - before the "ip=" and "nfsaddrs=" kernel command line parameters are
   parsed (in ip_auto_config_setup());
 - before autoconfiguring via DHCP or BOOTP (in ic_bootp_init()), in
   order to clear any values that may have been set after parsing "ip="
   or "nfsaddrs=" and are no longer needed.

This means that ic_nameservers_predef() is not called when neither "ip="
nor "nfsaddrs=" is specified on the kernel command line. In this
scenario, every element in ic_nameservers remains set to 0x00000000,
which is indistinguishable from ANY and causes pnp_seq_show() to write
the following (bogus) information to /proc/net/pnp:

  #MANUAL
  nameserver 0.0.0.0
  nameserver 0.0.0.0
  nameserver 0.0.0.0

This is potentially problematic for systems that blindly link
/etc/resolv.conf to /proc/net/pnp.

Ensure that ic_nameservers is also initialised when neither "ip=" nor
"nfsaddrs=" are specified by calling ic_nameservers_predef() in
ip_auto_config(), but only when ip_auto_config_setup() was not called
earlier. This causes the following to be written to /proc/net/pnp, and
is consistent with what gets written when ipconfig is configured
manually but no name servers are specified on the kernel command line:

  #MANUAL
Signed-off-by: NChris Novakovic <chris@chrisn.me.uk>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Fully document the format used by the /proc/net/pnp file written by
ipconfig, explain where its values originate from, and clarify that the
tertiary name server IP and DNS domain name are only written to the file
when autoconfiguration is used.
Signed-off-by: NChris Novakovic <chris@chrisn.me.uk>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When ipconfig is autoconfigured via BOOTP, the request packet
initialised by ic_bootp_init_ext() always allocates 8 bytes for the name
server option, limiting the BOOTP server to responding with at most 2
name servers even though ipconfig in fact supports an arbitrary number
of name servers (as defined by CONF_NAMESERVERS_MAX, which is currently
3).

Only request name servers in the request packet if CONF_NAMESERVERS_MAX
is positive (to comply with [1, §3.8]), and allocate enough space in the
packet for CONF_NAMESERVERS_MAX name servers to indicate the maximum
number we can accept in response.

[1] RFC 2132, "DHCP Options and BOOTP Vendor Extensions":
    https://tools.ietf.org/rfc/rfc2132.txtSigned-off-by: NChris Novakovic <chris@chrisn.me.uk>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When ipconfig is autoconfigured via BOOTP, the request packet
initialised by ic_bootp_init_ext() allocates 8 bytes for tag 5 ("Name
Server" [1, §3.7]), but tag 5 in the response isn't processed by
ic_do_bootp_ext(). Instead, allocate the 8 bytes to tag 6 ("Domain Name
Server" [1, §3.8]), which is processed by ic_do_bootp_ext(), and appears
to have been the intended tag to request.

This won't cause any breakage for existing users, as tag 5 responses
provided by BOOTP servers weren't being processed anyway.

[1] RFC 2132, "DHCP Options and BOOTP Vendor Extensions":
    https://tools.ietf.org/rfc/rfc2132.txtSigned-off-by: NChris Novakovic <chris@chrisn.me.uk>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Commit 5e953778 ("ipconfig: add
nameserver IPs to kernel-parameter ip=") adds the IP addresses of
discovered name servers to the summary printed by ipconfig when
configuration is complete. It appears the intention in ip_auto_config()
was to print the name servers on a new line (especially given the
spacing and lack of comma before "nameserver0="), but they're actually
printed on the same line as the NFS root filesystem configuration
summary:

  [    0.686186] IP-Config: Complete:
  [    0.686226]      device=eth0, hwaddr=xx:xx:xx:xx:xx:xx, ipaddr=10.0.0.2, mask=255.255.255.0, gw=10.0.0.1
  [    0.686328]      host=test, domain=example.com, nis-domain=(none)
  [    0.686386]      bootserver=10.0.0.1, rootserver=10.0.0.1, rootpath=     nameserver0=10.0.0.1

This makes it harder to read and parse ipconfig's output. Instead, print
the name servers on a separate line:

  [    0.791250] IP-Config: Complete:
  [    0.791289]      device=eth0, hwaddr=xx:xx:xx:xx:xx:xx, ipaddr=10.0.0.2, mask=255.255.255.0, gw=10.0.0.1
  [    0.791407]      host=test, domain=example.com, nis-domain=(none)
  [    0.791475]      bootserver=10.0.0.1, rootserver=10.0.0.1, rootpath=
  [    0.791476]      nameserver0=10.0.0.1
Signed-off-by: NChris Novakovic <chris@chrisn.me.uk>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

ic_do_bootp_ext() is responsible for parsing the "ip=" and "nfsaddrs="
kernel parameters. If a "." character is found in parameter 4 (the
client's hostname), everything before the first "." is used as the
hostname, and everything after it is used as the NIS domain name (but
not necessarily the DNS domain name).

Document this behaviour in Documentation/filesystems/nfs/nfsroot.txt,
as it is not made explicit.
Signed-off-by: NChris Novakovic <chris@chrisn.me.uk>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

NeilBrown says:

====================
A few rhashtables cleanups

2 patches fixes documentation
1 fixes a bit in rhashtable_walk_start()
1 improves rhashtable_walk stability.

All reviewed and Acked.
====================
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When a walk of an rhashtable is interrupted with rhastable_walk_stop()
and then rhashtable_walk_start(), the location to restart from is based
on a 'skip' count in the current hash chain, and this can be incorrect
if insertions or deletions have happened.  This does not happen when
the walk is not stopped and started as iter->p is a placeholder which
is safe to use while holding the RCU read lock.

In rhashtable_walk_start() we can revalidate that 'p' is still in the
same hash chain.  If it isn't then the current method is still used.

With this patch, if a rhashtable walker ensures that the current
object remains in the table over a stop/start period (possibly by
elevating the reference count if that is sufficient), it can be sure
that a walk will not miss objects that were in the hashtable for the
whole time of the walk.

rhashtable_walk_start() may not find the object even though it is
still in the hashtable if a rehash has moved it to a new table.  In
this case it will (eventually) get -EAGAIN and will need to proceed
through the whole table again to be sure to see everything at least
once.
Acked-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NNeilBrown <neilb@suse.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

The documentation claims that when rhashtable_walk_start_check()
detects a resize event, it will rewind back to the beginning
of the table.  This is not true.  We need to set ->slot and
->skip to be zero for it to be true.
Acked-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NNeilBrown <neilb@suse.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Neither rhashtable_walk_enter() or rhltable_walk_enter() sleep, though
they do take a spinlock without irq protection.
So revise the comments to accurately state the contexts in which
these functions can be called.
Acked-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NNeilBrown <neilb@suse.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

grow_decision and shink_decision no longer exist, so remove
the remaining references to them.
Acked-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NNeilBrown <neilb@suse.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

RETPOLINE made calls to tp->af_specific->md5_lookup() quite expensive,
given they have no result.
We can omit the calls for sockets that have no md5 keys.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This reverts commit <c6849a3a> ("net: init sk_cookie for inet socket")

Per discussion with Eric, when update sock_net(sk)->cookie_gen, the
whole cache cache line will be invalidated, as this cache line is shared
with all cpus, that may cause great performace hit.

Bellow is the data form Eric.
"Performance is reduced from ~5 Mpps to ~3.8 Mpps with 16 RX queues on
my host" when running synflood test.

Have to revert it to prevent from cache line false sharing.
Signed-off-by: NYafang Shao <laoar.shao@gmail.com>
Reviewed-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Tal Gilboa says:

====================
Introduce adaptive TX interrupt moderation to net DIM

Net DIM is a library designed for dynamic interrupt moderation. It was
implemented and optimized with receive side interrupts in mind, since these
are usually the CPU expensive ones. This patch-set introduces adaptive transmit
interrupt moderation to net DIM, complete with a usage in the mlx5e driver.
Using adaptive TX behavior would reduce interrupt rate for multiple scenarios.
Furthermore, it is essential for increasing bandwidth on cases where payload
aggregation is required.

v3: Remove "inline" from functions in .c files (requested by DaveM). Revert
adding "enabled" field from struct net_dim and applied mlx5e structural
suggestions (suggested by SaeedM).

v2: Rebase over proper tree.

v1: Fix compilation issues due to missed function renaming.
====================
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Add support for adaptive TX moderation. This greatly reduces TX interrupt
rate and increases bandwidth, mostly for TCP bandwidth over ARM
architecture (below). There is a slight single stream TCP with very large
message sizes degradation (x86). In this case if there's any moderation on
transmitted packets the bandwidth would reduce due to hitting TCP output limit.
Since this is a synthetic case, this is still worth doing.

Performance improvement (ConnectX-4Lx 40GbE, ARM)
TCP 64B bandwidth with 1-50 streams increased 6-35%.
TCP 64B bandwidth with 100-500 streams increased 20-70%.

Performance improvement (ConnectX-5 100GbE, x86)
Bandwidth: increased up to 40% (1024B with 10s of streams).
Interrupt rate: reduced up to 50% (1024B with 1000s of streams).

Performance degradation (ConnectX-5 100GbE, x86)
Bandwidth: up to 10% decrease single stream TCP (1MB message size from
51Gb/s to 47Gb/s).
Signed-off-by: NTal Gilboa <talgi@mellanox.com>
Reviewed-by: NTariq Toukan <tariqt@mellanox.com>
Acked-by: NSaeed Mahameed <saeedm@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Interrupt moderation for TX traffic requires different profiles than RX
interrupt moderation. The main goal here is to reduce interrupt rate and
allow better payload aggregation by keeping SKBs in the TX queue a bit
longer. Ping-pong behavior would get a profile with a short timer, so
latency wouldn't increase for these scenarios. There might be a slight
degradation in bandwidth for single stream with large message sizes, since
net.ipv4.tcp_limit_output_bytes is limiting the allowed TX traffic, but
with many streams performance is always improved.
Signed-off-by: NTal Gilboa <talgi@mellanox.com>
Reviewed-by: NTariq Toukan <tariqt@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Preparation for introducing adaptive TX to net DIM.
Signed-off-by: NTal Gilboa <talgi@mellanox.com>
Reviewed-by: NTariq Toukan <tariqt@mellanox.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Similar to commit a2ac9990 ("vhost-net: set packet weight of
tx polling to 2 * vq size"), we need a packet-based limit for
handler_rx, too - elsewhere, under rx flood with small packets,
tx can be delayed for a very long time, even without busypolling.

The pkt limit applied to handle_rx must be the same applied by
handle_tx, or we will get unfair scheduling between rx and tx.
Tying such limit to the queue length makes it less effective for
large queue length values and can introduce large process
scheduler latencies, so a constant valued is used - likewise
the existing bytes limit.

The selected limit has been validated with PVP[1] performance
test with different queue sizes:

queue size		256	512	1024

baseline		366	354	362
weight 128		715	723	670
weight 256		740	745	733
weight 512		600	460	583
weight 1024		423	427	418

A packet weight of 256 gives peek performances in under all the
tested scenarios.

No measurable regression in unidirectional performance tests has
been detected.

[1] https://developers.redhat.com/blog/2017/06/05/measuring-and-comparing-open-vswitch-performance/Signed-off-by: NPaolo Abeni <pabeni@redhat.com>
Acked-by: NJason Wang <jasowang@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Fixes: b16fb418 ("net: fib_rules: add extack support")
Signed-off-by: NRoopa Prabhu <roopa@cumulusnetworks.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Fixes: 192dc405 ("selftests: net: add tcp_mmap program")
Signed-off-by: NAnders Roxell <anders.roxell@linaro.org>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Function dca_common_get_tag is local to the source and does not need to be
in global scope, so make it static.

Cleans up sparse warning:
drivers/dca/dca-core.c:273:4: warning: symbol 'dca_common_get_tag' was
not declared. Should it be static?
Signed-off-by: NColin Ian King <colin.king@canonical.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

David Ahern says:

====================
net/ipv6: couple of fixes for rcu change to from

So many details... I am thankful for all the robots running the
permutations and tools.

Two bug fixes from the rcu change to rt->from:
1. missing rcu lock in ip6_negative_advice
2. rcu dereferences in 2 sites
====================
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

kbuild test robot reported 2 uses of rt->from not properly accessed
using rcu_dereference:
1. add rcu_dereference_protected to rt6_remove_exception_rt and make
   sure it is always called with rcu lock held.

2. change rt6_do_redirect to take a reference on 'from' when accessed
   the first time so it can be used the sceond time outside of the lock

Fixes: a68886a6 ("net/ipv6: Make from in rt6_info rcu protected")
Reported-by: Nkbuild test robot <lkp@intel.com>
Signed-off-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

syzbot reported a suspicious rcu_dereference_check:
  __dump_stack lib/dump_stack.c:77 [inline]
  dump_stack+0x1b9/0x294 lib/dump_stack.c:113
  lockdep_rcu_suspicious+0x14a/0x153 kernel/locking/lockdep.c:4592
  rt6_check_expired+0x38b/0x3e0 net/ipv6/route.c:410
  ip6_negative_advice+0x67/0xc0 net/ipv6/route.c:2204
  dst_negative_advice include/net/sock.h:1786 [inline]
  sock_setsockopt+0x138f/0x1fe0 net/core/sock.c:1051
  __sys_setsockopt+0x2df/0x390 net/socket.c:1899
  SYSC_setsockopt net/socket.c:1914 [inline]
  SyS_setsockopt+0x34/0x50 net/socket.c:1911

Add rcu locking around call to rt6_check_expired in
ip6_negative_advice.

Fixes: a68886a6 ("net/ipv6: Make from in rt6_info rcu protected")
Reported-by: syzbot+2422c9e35796659d2273@syzkaller.appspotmail.com
Signed-off-by: NDavid Ahern <dsahern@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Denis Bolotin says:

====================
Add configuration information to register dump and debug data

The purpose of this patchset is to add configuration information to the
debug data collection, which already contains register dump.
The first patch (removing the ptt) is essential because it prevents the
unnecessary ptt acquirement when calling mcp APIs.
====================
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Configuration information is added to the debug data collection, in
addition to register dump.
Added qed_dbg_nvm_image() that receives an image type, allocates a
buffer and reads the image. The images are saved in the buffers and the
dump size is updated.
Signed-off-by: NDenis Bolotin <denis.bolotin@cavium.com>
Signed-off-by: NAriel Elior <ariel.elior@cavium.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Since nvm images attributes are cached during driver load, acquiring ptt
is not needed when calling qed_mcp_get_nvm_image().
Signed-off-by: NDenis Bolotin <denis.bolotin@cavium.com>
Signed-off-by: NAriel Elior <ariel.elior@cavium.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Move all the core version detection to a common place ("hwif.c") and
implement a table which can be used to lookup the correct callbacks for
each IP version.

This simplifies the initialization flow of each IP version and eases
future implementation of new IP versions.
Signed-off-by: NJose Abreu <joabreu@synopsys.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Joao Pinto <jpinto@synopsys.com>
Cc: Vitor Soares <soares@synopsys.com>
Cc: Giuseppe Cavallaro <peppe.cavallaro@st.com>
Cc: Alexandre Torgue <alexandre.torgue@st.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

There's no benefit in using netif_info et al before the net_device has
been registered. We get messages like
r8169 0000:03:00.0 (unnamed net_device) (uninitialized): [message]
Therefore use dev_info/dev_err instead.

As a side effect we don't need parameter dev for function
rtl8169_get_mac_version() any longer.
Signed-off-by: NHeiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

With sk_cookie we can identify a socket, that is very helpful for
traceing and statistic, i.e. tcp tracepiont and ebpf.
So we'd better init it by default for inet socket.
When using it, we just need call atomic64_read(&sk->sk_cookie).
Signed-off-by: NYafang Shao <laoar.shao@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Roopa Prabhu says:

====================
fib rules extack support

First patch refactors code to move fib rule netlink handling
into a common function. This became obvious when adding
duplicate extack msgs in add and del paths. Second patch
adds extack msgs.

v2 - Dropped the ip route get support and selftests from
     the series to look at the input path some more (as pointed
     out by ido). Will come back to that next week when i have
     some time. resending just the extack part for now.
====================
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Signed-off-by: NRoopa Prabhu <roopa@cumulusnetworks.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This reduces code duplication in the fib rule add and del paths.
Get rid of validate_rulemsg. This became obvious when adding duplicate
extack support in fib newrule/delrule error paths.
Signed-off-by: NRoopa Prabhu <roopa@cumulusnetworks.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>