Merge tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-tracegrafted

Pull tracing fixes from Steven Rostedt:

 - Fix error output of boot instance creation failure

   Currently if a boot instance creation fails, instead of printing out
   the name of the instance that failed, it prints "(null)". That is
   because it prints "cur_str" that had already been processed by
   strsep(). Print the saved name instead.

   While at it, print the error code of the failure.

 - Fix use-after-free for same named historgrams

   Histograms can be named so that they can be used in multiple events.
   But if the named histogram has a variable attached, the second event
   that uses the named histogram which duplicates it and needs to free
   the original after duplication leaves the old variable in place and
   still visible. If another histogram uses than variable, it will use
   the stale one which will try to reference the freed duplicate
   histogram and crash the kernel.

   Free the duplicate variables along with the duplicated histogram
   data.

 - Check return value of kthread_run() in event self test

   The events self tests uses a kthread for testing but does not check
   if it succeeded in creating a kthread. If the kthread creation were
   to fail, the code will still try to call kthread_stop() on the error
   returned.

 - Fix race between reading trace_pipe and updating subbuffer size

   If a user is reading the trace_pipe file at the same time they update
   the ring buffer sub-buffer size, can cause the trace_pipe read to
   read stale data. Add trace_access_lock() around updating the ring
   buffer sub-buffer size.

 - Fix eventfs_inode on failure path in creation of the events directory

   In the creation of the "events" directory, if after allocating the
   eventfs_inode a failure is detected, it calls cleanup_ei() which
   calls free_ei(). The free_ei() will test if eventfs_inode being freed
   has no children. It is a bug if it does. But on the failure case of
   the creation of the "events" directory, the children lists have not
   yet been initialized and the free will trigger a warning because
   list_empty() on an uninitialized list returns false.

   Move the initialization into init_ei() where it makes more sense and
   makes sure that a created eventfs_inode has its lists initialized
   upon creation.

 - Check return value of kthread_run() in ftrace direct sample code

   The sample code that shows how to use the ftrace direct calls does
   not test the return of kthread_run() to see if it succeeds. Return a
   failure if the kthread_run() doesn't succeed.

 - Clear user events state on fork in case of alloc failure

   On fork, the child gets a pointer to the parent's user events state.
   It makes a copy of it then updates the child's pointer to it. But if
   the allocation fails, the duplication function leaves the child with
   a pointer to its parent's descriptor. When the child cleans up its
   data, it will free the parent's descriptor while the parent is still
   using it.

   In the duplication function, set the child's user_event_mm to NULL
   before testing if the allocation succeeded, and when it exits it will
   not free the parent's descriptor.

 - Fix retry exhaustion in simple ring buffer reader swap

   simple_ring_buffer_swap_reader_page() starts with retry set to 8 and
   post-decrements it only after a failed link replacement. On the final
   attempt, a successful replacement leaves retry at zero, while a
   failed replacement leaves it at -1.

   But the check for success expects the retry value to be non-zero and
   exits with an error on zero. This is the opposite result. Fix it.

 - Fail nicely when the remote swap_reader_page() returns an error

   Currently, if the swap_reader_page() of a remote buffer fails, it
   triggers a WARN_ON_ONCE() and continues normally. Instead, have it
   exit with an error and a pr_warn() print instead of a full WARNING.

* tag 'trace-v7.3-2' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  ring-buffer: Stop remote reader update when page swap fails
  tracing: Fix retry exhaustion in simple ring buffer reader swap
  tracing/user_events: Clear copied tracing state before fork duplication
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-multi-modify
  samples/ftrace: Fix kthread_stop() on ERR_PTR in ftrace-direct-modify
  eventfs: Initialize ei->children and ei->list in init_ei()
  tracing: Fix use-after-free in trace_pipe read on sub-buffer order change
  tracing: Fix crash passing ERR_PTR to kthread_stop()
  tracing: Fix use-after-free with same-name named triggers
  tracing: Fix logged instance name on creation failure

1 files changed, 464 insertions, 0 deletions

diff --git a/Documentation/networking/vrf.rst b/Documentation/networking/vrf.rst
new file mode 100644
index 000000000..0a9a6f968
--- /dev/null
+++ b/Documentation/networking/vrf.rst
@@ -0,0 +1,464 @@
+.. SPDX-License-Identifier: GPL-2.0
+
+====================================
+Virtual Routing and Forwarding (VRF)
+====================================
+
+The VRF Device
+==============
+
+The VRF device combined with ip rules provides the ability to create virtual
+routing and forwarding domains (aka VRFs, VRF-lite to be specific) in the
+Linux network stack. One use case is the multi-tenancy problem where each
+tenant has their own unique routing tables and in the very least need
+different default gateways.
+
+Processes can be "VRF aware" by binding a socket to the VRF device. Packets
+through the socket then use the routing table associated with the VRF
+device. An important feature of the VRF device implementation is that it
+impacts only Layer 3 and above so L2 tools (e.g., LLDP) are not affected
+(ie., they do not need to be run in each VRF). The design also allows
+the use of higher priority ip rules (Policy Based Routing, PBR) to take
+precedence over the VRF device rules directing specific traffic as desired.
+
+In addition, VRF devices allow VRFs to be nested within namespaces. For
+example network namespaces provide separation of network interfaces at the
+device layer, VLANs on the interfaces within a namespace provide L2 separation
+and then VRF devices provide L3 separation.
+
+Design
+------
+A VRF device is created with an associated route table. Network interfaces
+are then enslaved to a VRF device::
+
+	 +-----------------------------+
+	 |           vrf-blue          |  ===> route table 10
+	 +-----------------------------+
+	    |        |            |
+	 +------+ +------+     +-------------+
+	 | eth1 | | eth2 | ... |    bond1    |
+	 +------+ +------+     +-------------+
+				  |       |
+			      +------+ +------+
+			      | eth8 | | eth9 |
+			      +------+ +------+
+
+Packets received on an enslaved device and are switched to the VRF device
+in the IPv4 and IPv6 processing stacks giving the impression that packets
+flow through the VRF device. Similarly on egress routing rules are used to
+send packets to the VRF device driver before getting sent out the actual
+interface. This allows tcpdump on a VRF device to capture all packets into
+and out of the VRF as a whole\ [1]_. Similarly, netfilter\ [2]_ and tc rules
+can be applied using the VRF device to specify rules that apply to the VRF
+domain as a whole.
+
+.. [1] Packets in the forwarded state do not flow through the device, so those
+       packets are not seen by tcpdump. Will revisit this limitation in a
+       future release.
+
+.. [2] Iptables on ingress supports PREROUTING with skb->dev set to the real
+       ingress device and both INPUT and PREROUTING rules with skb->dev set to
+       the VRF device. For egress POSTROUTING and OUTPUT rules can be written
+       using either the VRF device or real egress device.
+
+Setup
+-----
+1. VRF device is created with an association to a FIB table.
+   e.g,::
+
+	ip link add vrf-blue type vrf table 10
+	ip link set dev vrf-blue up
+
+2. An l3mdev FIB rule directs lookups to the table associated with the device.
+   A single l3mdev rule is sufficient for all VRFs. The VRF device adds the
+   l3mdev rule for IPv4 and IPv6 when the first device is created with a
+   default preference of 1000. Users may delete the rule if desired and add
+   with a different priority or install per-VRF rules.
+
+   Prior to the v4.8 kernel iif and oif rules are needed for each VRF device::
+
+       ip ru add oif vrf-blue table 10
+       ip ru add iif vrf-blue table 10
+
+3. Set the default route for the table (and hence default route for the VRF)::
+
+       ip route add table 10 unreachable default metric 4278198272
+
+   This high metric value ensures that the default unreachable route can
+   be overridden by a routing protocol suite.  FRRouting interprets
+   kernel metrics as a combined admin distance (upper byte) and priority
+   (lower 3 bytes).  Thus the above metric translates to [255/8192].
+
+4. Enslave L3 interfaces to a VRF device::
+
+       ip link set dev eth1 master vrf-blue
+
+   Local and connected routes for enslaved devices are automatically moved to
+   the table associated with VRF device. Any additional routes depending on
+   the enslaved device are dropped and will need to be reinserted to the VRF
+   FIB table following the enslavement.
+
+   The IPv6 sysctl option keep_addr_on_down can be enabled to keep IPv6 global
+   addresses as VRF enslavement changes::
+
+       sysctl -w net.ipv6.conf.all.keep_addr_on_down=1
+
+5. Additional VRF routes are added to associated table::
+
+       ip route add table 10 ...
+
+
+Applications
+------------
+Applications that are to work within a VRF need to bind their socket to the
+VRF device::
+
+    setsockopt(sd, SOL_SOCKET, SO_BINDTODEVICE, dev, strlen(dev)+1);
+
+or to specify the output device using cmsg and IP_PKTINFO.
+
+By default the scope of the port bindings for unbound sockets is
+limited to the default VRF. That is, it will not be matched by packets
+arriving on interfaces enslaved to an l3mdev and processes may bind to
+the same port if they bind to an l3mdev.
+
+TCP & UDP services running in the default VRF context (ie., not bound
+to any VRF device) can work across all VRF domains by enabling the
+tcp_l3mdev_accept and udp_l3mdev_accept sysctl options::
+
+    sysctl -w net.ipv4.tcp_l3mdev_accept=1
+    sysctl -w net.ipv4.udp_l3mdev_accept=1
+
+These options are disabled by default so that a socket in a VRF is only
+selected for packets in that VRF. There is a similar option for RAW
+sockets, which is enabled by default for reasons of backwards compatibility.
+This is so as to specify the output device with cmsg and IP_PKTINFO, but
+using a socket not bound to the corresponding VRF. This allows e.g. older ping
+implementations to be run with specifying the device but without executing it
+in the VRF. This option can be disabled so that packets received in a VRF
+context are only handled by a raw socket bound to the VRF, and packets in the
+default VRF are only handled by a socket not bound to any VRF::
+
+    sysctl -w net.ipv4.raw_l3mdev_accept=0
+
+netfilter rules on the VRF device can be used to limit access to services
+running in the default VRF context as well.
+
+Using VRF-aware applications (applications which simultaneously create sockets
+outside and inside VRFs) in conjunction with ``net.ipv4.tcp_l3mdev_accept=1``
+is possible but may lead to problems in some situations. With that sysctl
+value, it is unspecified which listening socket will be selected to handle
+connections for VRF traffic; ie. either a socket bound to the VRF or an unbound
+socket may be used to accept new connections from a VRF. This somewhat
+unexpected behavior can lead to problems if sockets are configured with extra
+options (ex. TCP MD5 keys) with the expectation that VRF traffic will
+exclusively be handled by sockets bound to VRFs, as would be the case with
+``net.ipv4.tcp_l3mdev_accept=0``. Finally and as a reminder, regardless of
+which listening socket is selected, established sockets will be created in the
+VRF based on the ingress interface, as documented earlier.
+
+--------------------------------------------------------------------------------
+
+Using iproute2 for VRFs
+=======================
+iproute2 supports the vrf keyword as of v4.7. For backwards compatibility this
+section lists both commands where appropriate -- with the vrf keyword and the
+older form without it.
+
+1. Create a VRF
+
+   To instantiate a VRF device and associate it with a table::
+
+       $ ip link add dev NAME type vrf table ID
+
+   As of v4.8 the kernel supports the l3mdev FIB rule where a single rule
+   covers all VRFs. The l3mdev rule is created for IPv4 and IPv6 on first
+   device create.
+
+2. List VRFs
+
+   To list VRFs that have been created::
+
+       $ ip [-d] link show type vrf
+	 NOTE: The -d option is needed to show the table id
+
+   For example::
+
+       $ ip -d link show type vrf
+       11: mgmt: <NOARP,MASTER,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP mode DEFAULT group default qlen 1000
+	   link/ether 72:b3:ba:91:e2:24 brd ff:ff:ff:ff:ff:ff promiscuity 0
+	   vrf table 1 addrgenmode eui64
+       12: red: <NOARP,MASTER,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP mode DEFAULT group default qlen 1000
+	   link/ether b6:6f:6e:f6:da:73 brd ff:ff:ff:ff:ff:ff promiscuity 0
+	   vrf table 10 addrgenmode eui64
+       13: blue: <NOARP,MASTER,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP mode DEFAULT group default qlen 1000
+	   link/ether 36:62:e8:7d:bb:8c brd ff:ff:ff:ff:ff:ff promiscuity 0
+	   vrf table 66 addrgenmode eui64
+       14: green: <NOARP,MASTER,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast state UP mode DEFAULT group default qlen 1000
+	   link/ether e6:28:b8:63:70:bb brd ff:ff:ff:ff:ff:ff promiscuity 0
+	   vrf table 81 addrgenmode eui64
+
+
+   Or in brief output::
+
+       $ ip -br link show type vrf
+       mgmt         UP             72:b3:ba:91:e2:24 <NOARP,MASTER,UP,LOWER_UP>
+       red          UP             b6:6f:6e:f6:da:73 <NOARP,MASTER,UP,LOWER_UP>
+       blue         UP             36:62:e8:7d:bb:8c <NOARP,MASTER,UP,LOWER_UP>
+       green        UP             e6:28:b8:63:70:bb <NOARP,MASTER,UP,LOWER_UP>
+
+
+3. Assign a Network Interface to a VRF
+
+   Network interfaces are assigned to a VRF by enslaving the netdevice to a
+   VRF device::
+
+       $ ip link set dev NAME master NAME
+
+   On enslavement connected and local routes are automatically moved to the
+   table associated with the VRF device.
+
+   For example::
+
+       $ ip link set dev eth0 master mgmt
+
+
+4. Show Devices Assigned to a VRF
+
+   To show devices that have been assigned to a specific VRF add the master
+   option to the ip command::
+
+       $ ip link show vrf NAME
+       $ ip link show master NAME
+
+   For example::
+
+       $ ip link show vrf red
+       3: eth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast master red state UP mode DEFAULT group default qlen 1000
+	   link/ether 02:00:00:00:02:02 brd ff:ff:ff:ff:ff:ff
+       4: eth2: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast master red state UP mode DEFAULT group default qlen 1000
+	   link/ether 02:00:00:00:02:03 brd ff:ff:ff:ff:ff:ff
+       7: eth5: <BROADCAST,MULTICAST> mtu 1500 qdisc noop master red state DOWN mode DEFAULT group default qlen 1000
+	   link/ether 02:00:00:00:02:06 brd ff:ff:ff:ff:ff:ff
+
+
+   Or using the brief output::
+
+       $ ip -br link show vrf red
+       eth1             UP             02:00:00:00:02:02 <BROADCAST,MULTICAST,UP,LOWER_UP>
+       eth2             UP             02:00:00:00:02:03 <BROADCAST,MULTICAST,UP,LOWER_UP>
+       eth5             DOWN           02:00:00:00:02:06 <BROADCAST,MULTICAST>
+
+
+5. Show Neighbor Entries for a VRF
+
+   To list neighbor entries associated with devices enslaved to a VRF device
+   add the master option to the ip command::
+
+       $ ip [-6] neigh show vrf NAME
+       $ ip [-6] neigh show master NAME
+
+   For example::
+
+       $  ip neigh show vrf red
+       10.2.1.254 dev eth1 lladdr a6:d9:c7:4f:06:23 REACHABLE
+       10.2.2.254 dev eth2 lladdr 5e:54:01:6a:ee:80 REACHABLE
+
+       $ ip -6 neigh show vrf red
+       2002:1::64 dev eth1 lladdr a6:d9:c7:4f:06:23 REACHABLE
+
+
+6. Show Addresses for a VRF
+
+   To show addresses for interfaces associated with a VRF add the master
+   option to the ip command::
+
+       $ ip addr show vrf NAME
+       $ ip addr show master NAME
+
+   For example::
+
+	$ ip addr show vrf red
+	3: eth1: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast master red state UP group default qlen 1000
+	    link/ether 02:00:00:00:02:02 brd ff:ff:ff:ff:ff:ff
+	    inet 10.2.1.2/24 brd 10.2.1.255 scope global eth1
+	       valid_lft forever preferred_lft forever
+	    inet6 2002:1::2/120 scope global
+	       valid_lft forever preferred_lft forever
+	    inet6 fe80::ff:fe00:202/64 scope link
+	       valid_lft forever preferred_lft forever
+	4: eth2: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 qdisc pfifo_fast master red state UP group default qlen 1000
+	    link/ether 02:00:00:00:02:03 brd ff:ff:ff:ff:ff:ff
+	    inet 10.2.2.2/24 brd 10.2.2.255 scope global eth2
+	       valid_lft forever preferred_lft forever
+	    inet6 2002:2::2/120 scope global
+	       valid_lft forever preferred_lft forever
+	    inet6 fe80::ff:fe00:203/64 scope link
+	       valid_lft forever preferred_lft forever
+	7: eth5: <BROADCAST,MULTICAST> mtu 1500 qdisc noop master red state DOWN group default qlen 1000
+	    link/ether 02:00:00:00:02:06 brd ff:ff:ff:ff:ff:ff
+
+   Or in brief format::
+
+	$ ip -br addr show vrf red
+	eth1             UP             10.2.1.2/24 2002:1::2/120 fe80::ff:fe00:202/64
+	eth2             UP             10.2.2.2/24 2002:2::2/120 fe80::ff:fe00:203/64
+	eth5             DOWN
+
+
+7. Show Routes for a VRF
+
+   To show routes for a VRF use the ip command to display the table associated
+   with the VRF device::
+
+       $ ip [-6] route show vrf NAME
+       $ ip [-6] route show table ID
+
+   For example::
+
+	$ ip route show vrf red
+	unreachable default  metric 4278198272
+	broadcast 10.2.1.0 dev eth1  proto kernel  scope link  src 10.2.1.2
+	10.2.1.0/24 dev eth1  proto kernel  scope link  src 10.2.1.2
+	local 10.2.1.2 dev eth1  proto kernel  scope host  src 10.2.1.2
+	broadcast 10.2.1.255 dev eth1  proto kernel  scope link  src 10.2.1.2
+	broadcast 10.2.2.0 dev eth2  proto kernel  scope link  src 10.2.2.2
+	10.2.2.0/24 dev eth2  proto kernel  scope link  src 10.2.2.2
+	local 10.2.2.2 dev eth2  proto kernel  scope host  src 10.2.2.2
+	broadcast 10.2.2.255 dev eth2  proto kernel  scope link  src 10.2.2.2
+
+	$ ip -6 route show vrf red
+	local 2002:1:: dev lo  proto none  metric 0  pref medium
+	local 2002:1::2 dev lo  proto none  metric 0  pref medium
+	2002:1::/120 dev eth1  proto kernel  metric 256  pref medium
+	local 2002:2:: dev lo  proto none  metric 0  pref medium
+	local 2002:2::2 dev lo  proto none  metric 0  pref medium
+	2002:2::/120 dev eth2  proto kernel  metric 256  pref medium
+	local fe80:: dev lo  proto none  metric 0  pref medium
+	local fe80:: dev lo  proto none  metric 0  pref medium
+	local fe80::ff:fe00:202 dev lo  proto none  metric 0  pref medium
+	local fe80::ff:fe00:203 dev lo  proto none  metric 0  pref medium
+	fe80::/64 dev eth1  proto kernel  metric 256  pref medium
+	fe80::/64 dev eth2  proto kernel  metric 256  pref medium
+	ff00::/8 dev red  metric 256  pref medium
+	ff00::/8 dev eth1  metric 256  pref medium
+	ff00::/8 dev eth2  metric 256  pref medium
+	unreachable default dev lo  metric 4278198272  error -101 pref medium
+
+8. Route Lookup for a VRF
+
+   A test route lookup can be done for a VRF::
+
+       $ ip [-6] route get vrf NAME ADDRESS
+       $ ip [-6] route get oif NAME ADDRESS
+
+   For example::
+
+	$ ip route get 10.2.1.40 vrf red
+	10.2.1.40 dev eth1  table red  src 10.2.1.2
+	    cache
+
+	$ ip -6 route get 2002:1::32 vrf red
+	2002:1::32 from :: dev eth1  table red  proto kernel  src 2002:1::2  metric 256  pref medium
+
+
+9. Removing Network Interface from a VRF
+
+   Network interfaces are removed from a VRF by breaking the enslavement to
+   the VRF device::
+
+       $ ip link set dev NAME nomaster
+
+   Connected routes are moved back to the default table and local entries are
+   moved to the local table.
+
+   For example::
+
+    $ ip link set dev eth0 nomaster
+
+--------------------------------------------------------------------------------
+
+Commands used in this example::
+
+     cat >> /etc/iproute2/rt_tables.d/vrf.conf <<EOF
+     1  mgmt
+     10 red
+     66 blue
+     81 green
+     EOF
+
+     function vrf_create
+     {
+	 VRF=$1
+	 TBID=$2
+
+	 # create VRF device
+	 ip link add ${VRF} type vrf table ${TBID}
+
+	 if [ "${VRF}" != "mgmt" ]; then
+	     ip route add table ${TBID} unreachable default metric 4278198272
+	 fi
+	 ip link set dev ${VRF} up
+     }
+
+     vrf_create mgmt 1
+     ip link set dev eth0 master mgmt
+
+     vrf_create red 10
+     ip link set dev eth1 master red
+     ip link set dev eth2 master red
+     ip link set dev eth5 master red
+
+     vrf_create blue 66
+     ip link set dev eth3 master blue
+
+     vrf_create green 81
+     ip link set dev eth4 master green
+
+
+     Interface addresses from /etc/network/interfaces:
+     auto eth0
+     iface eth0 inet static
+	   address 10.0.0.2
+	   netmask 255.255.255.0
+	   gateway 10.0.0.254
+
+     iface eth0 inet6 static
+	   address 2000:1::2
+	   netmask 120
+
+     auto eth1
+     iface eth1 inet static
+	   address 10.2.1.2
+	   netmask 255.255.255.0
+
+     iface eth1 inet6 static
+	   address 2002:1::2
+	   netmask 120
+
+     auto eth2
+     iface eth2 inet static
+	   address 10.2.2.2
+	   netmask 255.255.255.0
+
+     iface eth2 inet6 static
+	   address 2002:2::2
+	   netmask 120
+
+     auto eth3
+     iface eth3 inet static
+	   address 10.2.3.2
+	   netmask 255.255.255.0
+
+     iface eth3 inet6 static
+	   address 2002:3::2
+	   netmask 120
+
+     auto eth4
+     iface eth4 inet static
+	   address 10.2.4.2
+	   netmask 255.255.255.0
+
+     iface eth4 inet6 static
+	   address 2002:4::2
+	   netmask 120