Pull perf event fix from Thomas Gleixner:
 "A single fix for the perf core where a value read with READ_ONCE() was
  checked and then reread which makes all the checks invalid. Reuse the
  already read value instead"

* tag 'perf-urgent-2021-09-19' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  events: Reuse value read using READ_ONCE instead of re-reading it

Pull locking fixes from Thomas Gleixner:
 "A set of updates for the RT specific reader/writer locking base code:

   - Make the fast path reader ordering guarantees correct.

   - Code reshuffling to make the fix simpler"

[ This plays ugly games with atomic_add_return_release() because we
  don't have a plain atomic_add_release(), and should really be cleaned
  up, I think    - Linus ]

* tag 'locking-urgent-2021-09-19' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  locking/rwbase: Take care of ordering guarantee for fastpath reader
  locking/rwbase: Extract __rwbase_write_trylock()
  locking/rwbase: Properly match set_and_save_state() to restore_state()

Pull dma-mapping fixes from Christoph Hellwig:

 - page align size in sparc32 arch_dma_alloc (Andreas Larsson)

 - tone down a new dma-debug message (Hamza Mahfooz)

 - fix the kerneldoc for dma_map_sg_attrs (me)

* tag 'dma-mapping-5.15-1' of git://git.infradead.org/users/hch/dma-mapping:
  sparc32: page align size in arch_dma_alloc
  dma-debug: prevent an error message from causing runtime problems
  dma-mapping: fix the kerneldoc for dma_map_sg_attrs

Pull networking fixes from Jakub Kicinski:
 "Including fixes from bpf.

  Current release - regressions:

   - vhost_net: fix OoB on sendmsg() failure

   - mlx5: bridge, fix uninitialized variable usage

   - bnxt_en: fix error recovery regression

  Current release - new code bugs:

   - bpf, mm: fix lockdep warning triggered by stack_map_get_build_id_offset()

  Previous releases - regressions:

   - r6040: restore MDIO clock frequency after MAC reset

   - tcp: fix tp->undo_retrans accounting in tcp_sacktag_one()

   - dsa: flush switchdev workqueue before tearing down CPU/DSA ports

  Previous releases - always broken:

   - ptp: dp83640: don't define PAGE0, avoid compiler warning

   - igc: fix tunnel segmentation offloads

   - phylink: update SFP selected interface on advertising changes

   - stmmac: fix system hang caused by eee_ctrl_timer during suspend/resume

   - mlx5e: fix mutual exclusion between CQE compression and HW TS

  Misc:

   - bpf, cgroups: fix cgroup v2 fallback on v1/v2 mixed mode

   - sfc: fallback for lack of xdp tx queues

   - hns3: add option to turn off page pool feature"

* tag 'net-5.15-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (67 commits)
  mlxbf_gige: clear valid_polarity upon open
  igc: fix tunnel offloading
  net/{mlx5|nfp|bnxt}: Remove unnecessary RTNL lock assert
  net: wan: wanxl: define CROSS_COMPILE_M68K
  selftests: nci: replace unsigned int with int
  net: dsa: flush switchdev workqueue before tearing down CPU/DSA ports
  Revert "net: phy: Uniform PHY driver access"
  net: dsa: destroy the phylink instance on any error in dsa_slave_phy_setup
  ptp: dp83640: don't define PAGE0
  bnx2x: Fix enabling network interfaces without VFs
  Revert "Revert "ipv4: fix memory leaks in ip_cmsg_send() callers""
  tcp: fix tp->undo_retrans accounting in tcp_sacktag_one()
  net-caif: avoid user-triggerable WARN_ON(1)
  bpf, selftests: Add test case for mixed cgroup v1/v2
  bpf, selftests: Add cgroup v1 net_cls classid helpers
  bpf, cgroups: Fix cgroup v2 fallback on v1/v2 mixed mode
  bpf: Add oversize check before call kvcalloc()
  net: hns3: fix the timing issue of VF clearing interrupt sources
  net: hns3: fix the exception when query imp info
  net: hns3: disable mac in flr process
  ...

Readers of rwbase can lock and unlock without taking any inner lock, if
that happens, we need the ordering provided by atomic operations to
satisfy the ordering semantics of lock/unlock. Without that, considering
the follow case:

	{ X = 0 initially }

	CPU 0			CPU 1
	=====			=====
				rt_write_lock();
				X = 1
				rt_write_unlock():
				  atomic_add(READER_BIAS - WRITER_BIAS, ->readers);
				  // ->readers is READER_BIAS.
	rt_read_lock():
	  if ((r = atomic_read(->readers)) < 0) // True
	    atomic_try_cmpxchg(->readers, r, r + 1); // succeed.
	  <acquire the read lock via fast path>

	r1 = X;	// r1 may be 0, because nothing prevent the reordering
	        // of "X=1" and atomic_add() on CPU 1.

Therefore audit every usage of atomic operations that may happen in a
fast path, and add necessary barriers.

Signed-off-by: Boqun Feng <boqun.feng@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/20210909110203.953991276@infradead.org

The code in rwbase_write_lock() is a little non-obvious vs the
read+set 'trylock', extract the sequence into a helper function to
clarify the code.

This also provides a single site to fix fast-path ordering.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/YUCq3L+u44NDieEJ@hirez.programming.kicks-ass.net

Noticed while looking at the readers race.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Will Deacon <will@kernel.org>
Link: https://lkml.kernel.org/r/20210909110203.828203010@infradead.org

In perf_event_addr_filters_apply, the task associated with
the event (event->ctx->task) is read using READ_ONCE at the beginning
of the function, checked, and then re-read from event->ctx->task,
voiding all guarantees of the checks. Reuse the value that was read by
READ_ONCE to ensure the consistency of the task struct throughout the
function.

Fixes: 375637bc52495 ("perf/core: Introduce address range filtering")
Signed-off-by: Baptiste Lepers <baptiste.lepers@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20210906015310.12802-1-baptiste.lepers@gmail.com

The boot-time allocation interface for memblock is a mess, with
'memblock_alloc()' returning a virtual pointer, but then you are
supposed to free it with 'memblock_free()' that takes a _physical_
address.

Not only is that all kinds of strange and illogical, but it actually
causes bugs, when people then use it like a normal allocation function,
and it fails spectacularly on a NULL pointer:

   https://lore.kernel.org/all/20210912140820.GD25450@xsang-OptiPlex-9020/

or just random memory corruption if the debug checks don't catch it:

   https://lore.kernel.org/all/61ab2d0c-3313-aaab-514c-e15b7aa054a0@suse.cz/

I really don't want to apply patches that treat the symptoms, when the
fundamental cause is this horribly confusing interface.

I started out looking at just automating a sane replacement sequence,
but because of this mix or virtual and physical addresses, and because
people have used the "__pa()" macro that can take either a regular
kernel pointer, or just the raw "unsigned long" address, it's all quite
messy.

So this just introduces a new saner interface for freeing a virtual
address that was allocated using 'memblock_alloc()', and that was kept
as a regular kernel pointer.  And then it converts a couple of users
that are obvious and easy to test, including the 'xbc_nodes' case in
lib/bootconfig.c that caused problems.

Reported-by: kernel test robot <oliver.sang@intel.com>
Fixes: 40caa127f3c7 ("init: bootconfig: Remove all bootconfig data when the init memory is removed")
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Daniel Borkmann says:

====================
pull-request: bpf 2021-09-14

The following pull-request contains BPF updates for your *net* tree.

We've added 7 non-merge commits during the last 13 day(s) which contain
a total of 18 files changed, 334 insertions(+), 193 deletions(-).

The main changes are:

1) Fix mmap_lock lockdep splat in BPF stack map's build_id lookup, from Yonghong Song.

2) Fix BPF cgroup v2 program bypass upon net_cls/prio activation, from Daniel Borkmann.

3) Fix kvcalloc() BTF line info splat on oversized allocation attempts, from Bixuan Cui.

4) Fix BPF selftest build of task_pt_regs test for arm64/s390, from Jean-Philippe Brucker.

5) Fix BPF's disasm.{c,h} to dual-license so that it is aligned with bpftool given the former
   is a build dependency for the latter, from Daniel Borkmann with ACKs from contributors.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>