Commit fa2c3254d7cf (sched/tracing: Don't re-read p->state when emitting
sched_switch event, 2022-01-20) added a new prev_state argument to the
sched_switch tracepoint, before the prev task_struct pointer.

This reordering of arguments broke BPF programs that use the raw
tracepoint (e.g. tp_btf programs). The type of the second argument has
changed and existing programs that assume a task_struct* argument
(e.g. for bpf_task_storage access) will now fail to verify.

If we instead append the new argument to the end, all existing programs
would continue to work and can conditionally extract the prev_state
argument on supported kernel versions.

Fixes: fa2c3254d7cf (sched/tracing: Don't re-read p->state when emitting sched_switch event, 2022-01-20)
Signed-off-by: Delyan Kratunov <delyank@fb.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Link: https://lkml.kernel.org/r/c8a6930dfdd58a4a5755fc01732675472979732b.camel@fb.com

Pull networking fixes from Paolo Abeni:
 "Including fixes from bpf and netfilter.

  Current release - new code bugs:

   - mctp: correct mctp_i2c_header_create result

   - eth: fungible: fix reference to __udivdi3 on 32b builds

   - eth: micrel: remove latencies support lan8814

  Previous releases - regressions:

   - bpf: resolve to prog->aux->dst_prog->type only for BPF_PROG_TYPE_EXT

   - vrf: fix packet sniffing for traffic originating from ip tunnels

   - rxrpc: fix a race in rxrpc_exit_net()

   - dsa: revert "net: dsa: stop updating master MTU from master.c"

   - eth: ice: fix MAC address setting

  Previous releases - always broken:

   - tls: fix slab-out-of-bounds bug in decrypt_internal

   - bpf: support dual-stack sockets in bpf_tcp_check_syncookie

   - xdp: fix coalescing for page_pool fragment recycling

   - ovs: fix leak of nested actions

   - eth: sfc:
      - add missing xdp queue reinitialization
      - fix using uninitialized xdp tx_queue

   - eth: ice:
      - clear default forwarding VSI during VSI release
      - fix broken IFF_ALLMULTI handling
      - synchronize_rcu() when terminating rings

   - eth: qede: confirm skb is allocated before using

   - eth: aqc111: fix out-of-bounds accesses in RX fixup

   - eth: slip: fix NPD bug in sl_tx_timeout()"

* tag 'net-5.18-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (61 commits)
  drivers: net: slip: fix NPD bug in sl_tx_timeout()
  bpf: Adjust bpf_tcp_check_syncookie selftest to test dual-stack sockets
  bpf: Support dual-stack sockets in bpf_tcp_check_syncookie
  myri10ge: fix an incorrect free for skb in myri10ge_sw_tso
  net: usb: aqc111: Fix out-of-bounds accesses in RX fixup
  qede: confirm skb is allocated before using
  net: ipv6mr: fix unused variable warning with CONFIG_IPV6_PIMSM_V2=n
  net: phy: mscc-miim: reject clause 45 register accesses
  net: axiemac: use a phandle to reference pcs_phy
  dt-bindings: net: add pcs-handle attribute
  net: axienet: factor out phy_node in struct axienet_local
  net: axienet: setup mdio unconditionally
  net: sfc: fix using uninitialized xdp tx_queue
  rxrpc: fix a race in rxrpc_exit_net()
  net: openvswitch: fix leak of nested actions
  net: ethernet: mv643xx: Fix over zealous checking of_get_mac_address()
  net: openvswitch: don't send internal clone attribute to the userspace.
  net: micrel: Fix KS8851 Kconfig
  ice: clear cmd_type_offset_bsz for TX rings
  ice: xsk: fix VSI state check in ice_xsk_wakeup()
  ...

Pull more tracing updates from Steven Rostedt:

 - Rename the staging files to give them some meaning. Just
   stage1,stag2,etc, does not show what they are for

 - Check for NULL from allocation in bootconfig

 - Hold event mutex for dyn_event call in user events

 - Mark user events to broken (to work on the API)

 - Remove eBPF updates from user events

 - Remove user events from uapi header to keep it from being installed.

 - Move ftrace_graph_is_dead() into inline as it is called from hot
   paths and also convert it into a static branch.

* tag 'trace-v5.18-2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing: Move user_events.h temporarily out of include/uapi
  ftrace: Make ftrace_graph_is_dead() a static branch
  tracing: Set user_events to BROKEN
  tracing/user_events: Remove eBPF interfaces
  tracing/user_events: Hold event_mutex during dyn_event_add
  proc: bootconfig: Add null pointer check
  tracing: Rename the staging files for trace_events

After being merged, user_events become more visible to a wider audience
that have concerns with the current API.

It is too late to fix this for this release, but instead of a full
revert, just mark it as BROKEN (which prevents it from being selected in
make config).  Then we can work finding a better API.  If that fails,
then it will need to be completely reverted.

To not have the code silently bitrot, still allow building it with
COMPILE_TEST.

And to prevent the uapi header from being installed, then later changed,
and then have an old distro user space see the old version, move the
header file out of the uapi directory.

Surround the include with CONFIG_COMPILE_TEST to the current location,
but when the BROKEN tag is taken off, it will use the uapi directory,
and fail to compile.  This is a good way to remind us to move the header
back.

Link: https://lore.kernel.org/all/20220330155835.5e1f6669@gandalf.local.home
Link: https://lkml.kernel.org/r/20220330201755.29319-1-mathieu.desnoyers@efficios.com
Suggested-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

While user_events API is under development and has been marked for broken
to not let the API become fixed, move the header file out of the uapi
directory. This is to prevent it from being installed, then later changed,
and then have an old distro user space update with a new kernel, where
applications see the user_events being available, but the old header is in
place, and then they get compiled incorrectly.

Also, surround the include with CONFIG_COMPILE_TEST to the current
location, but when the BROKEN tag is taken off, it will use the uapi
directory, and fail to compile. This is a good way to remind us to move
the header back.

Link: https://lore.kernel.org/all/20220330155835.5e1f6669@gandalf.local.home
Link: https://lkml.kernel.org/r/20220330201755.29319-1-mathieu.desnoyers@efficios.com
Link: https://lkml.kernel.org/r/20220401143903.188384f3@gandalf.local.home

Suggested-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>

ftrace_graph_is_dead() is used on hot paths, it just reads a variable
in memory and is not worth suffering function call constraints.

For instance, at entry of prepare_ftrace_return(), inlining it avoids
saving prepare_ftrace_return() parameters to stack and restoring them
after calling ftrace_graph_is_dead().

While at it using a static branch is even more performant and is
rather well adapted considering that the returned value will almost
never change.

Inline ftrace_graph_is_dead() and replace 'kill_ftrace_graph' bool
by a static branch.

The performance improvement is noticeable.

Link: https://lkml.kernel.org/r/e0411a6a0ed3eafff0ad2bc9cd4b0e202b4617df.1648623570.git.christophe.leroy@csgroup.eu

Signed-off-by: Christophe Leroy <christophe.leroy@csgroup.eu>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>

After being merged, user_events become more visible to a wider audience
that have concerns with the current API. It is too late to fix this for
this release, but instead of a full revert, just mark it as BROKEN (which
prevents it from being selected in make config). Then we can work finding
a better API. If that fails, then it will need to be completely reverted.

Link: https://lore.kernel.org/all/2059213643.196683.1648499088753.JavaMail.zimbra@efficios.com/
Link: https://lkml.kernel.org/r/20220330155835.5e1f6669@gandalf.local.home

Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>

Remove eBPF interfaces within user_events to ensure they are fully
reviewed.

Link: https://lore.kernel.org/all/20220329165718.GA10381@kbox/
Link: https://lkml.kernel.org/r/20220329173051.10087-1-beaub@linux.microsoft.com

Suggested-by: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Signed-off-by: Beau Belgrave <beaub@linux.microsoft.com>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>

Make sure the event_mutex is properly held during dyn_event_add call.
This is required when adding dynamic events.

Link: https://lkml.kernel.org/r/20220328223225.1992-1-beaub@linux.microsoft.com

Reported-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Beau Belgrave <beaub@linux.microsoft.com>
Acked-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Steven Rostedt (Google) <rostedt@goodmis.org>

Since the function pointered by rethook::handler never be removed when
the rethook is alive, it doesn't need to use rcu_assign_pointer() to
update it. Just use WRITE_ONCE().

Reported-by: Alexei Starovoitov <alexei.starovoitov@gmail.com>
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Link: https://lore.kernel.org/bpf/164868907688.21983.1606862921419988152.stgit@devnote2