kmod/core: fix relocation writes across page boundaries

The integration test suite was intermittently giving the following
error:

  [192685.907072] kpatch: write to 0xffffffffa082bffe failed for symbol call_netdevice_notifiers_info

The error was caused by a write across a page boundary without first
making the second page read/write.
Merge pull request #271 from jpoimboe/relocation-page-boundary

kmod/core: fix relocation writes across page boundaries
kmod/core: be more verbose when activness safety check fails

Print some basic info and stack trace for task when activness
safety check fails.

Signed-off-by: Jan Stancek <jstancek@redhat.com>
Merge pull request #266 from jstancek/safety_check_stacktrace

kmod/core: be more verbose when activness safety check fails
create-diff-object: fixup new function handling

The original logic in the inclusion tree code worked under the
assumption that it was the only code path marking symbols for inclusion.
Therefore, if the symbol had been marked as included, it could be safely
assumed that we also already called kpatch_include_symbol() on it.  With
the special section handling marking symbols as included, however, this
assumption is not valid.

We should call kpatch_include_symbol() regardless of whether or not the
symbol has already been marked as included or not in order to possible
include the symbol's entire bundle.

Signed-off-by: Seth Jennings <sjenning@redhat.com>