Multi-process based page-poisoning test program.

page-poisoning test program is an extension of tinjpage test program with a
multi-process model. It spawns thousands of processes that inject HWPosion
error to various pages simultaneously thru madvise syscall. Then it checks
if these errors get handled correctly, i.e. whether each test process
receives or doesn't receive SIGBUS signal as expected.

In details, page-poisoning is designed to cover all of possible userspace page
types via following two test operations:
  - anonymous pages operations.
  - file data operations.

You can get detailed help info in following way:
# ./page-poisoning -h