tracing: More fixes for v7.3

tracing fixes for 7.3:

- Use rcu_assign_pointer() for tmp_ops filter hash

The tmp_ops used in update_ftrace_direct_mod() assigns its filter_hash field directly, but that field is annotated as __rcu and sparse complains. Assign it with rcu_assign_pointer()

- Fix use-after-free in enable_trigger_private_data_free()

The trace_event_call is accessed through the event_trigger_data's trace_event_file pointer to put the trace_event_call on freeing. The issue is that the trace_event_file data may have been freed already causing a use-after-free. Add a field to the event_trigger_data that points directly to the trace_event_call so that it can decrement its reference directly without needing to go through the trace_event_file.

- Fix accounting of buffer data remote headers

trace_buffer_desc_size() and trace_remote_alloc_buffer() undercount the number of pages is needed for the asked for size as it doesn't take into account the meta data on each page. Add a helper function to do the calculation properly and use that in these functions.

- Catch nr_page_va overflow in ring_buffer_desc sizing

The number of pages per remote ring buffer is capped by ring_buffer_desc::nr_page_va (32 bits). A buffer_size large enough to overflow that field would silently allocate a descriptor smaller than what was asked for.

- Do not resize the subbuf order if any per_cpu buffer is disabled

The mmapping of ring buffers disables resizing the subbuffers, but it is done per-cpu whereas the subbuf size change is done for all the per_cpu buffers under the buffer->mutex. It could change the size of some while the mapping is happening on others. Have the resize of the subbuf order check all the per_cpu buffers under the lock to see if any of them is disabled before starting and causing an inconsistency between buffers that are being mapped.

git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace.git
trace/fixes

Head SHA1: d860c67c051685abb0460b593b193f0f45f4fa92

Ali Ahmet Memiş (1):
tracing: Don't dereference trace_event_file in deferred trigger free

David Carlier (1):
ring-buffer: Check resize_disabled before publishing the new subbuf order

Leon Hwang (1):
ftrace: Use rcu_assign_pointer() for tmp_ops filter hash

Vincent Donnefort (2):
tracing/remotes: Account for ring buffer page header in size calculation tracing/remotes: Catch nr_page_va overflow in ring_buffer_desc sizing

----

 include/linux/ring_buffer.h         | 19 +++++++++++++++++--
 kernel/trace/ftrace.c               |  2 +-
 kernel/trace/ring_buffer.c          |  8 ++++++++
 kernel/trace/trace.h                |  1 +
 kernel/trace/trace_events_trigger.c |  4 +++-
 kernel/trace/trace_remote.c         |  6 +++++-
 6 files changed, 35 insertions(+), 5 deletions(-)