[Crash-utility] [Crash-Utility] extensions/trace: Add support for multiple ftrace buffers

[Kyle Tomsic]

This is my first time submitting a patch to a mailing list, so please be
patient with me if I've made any mistakes.

Since the 3.10 release, the Linux kernel has offered the ability to create
multiple independent ftrace buffers. At present, however, crash is only able to
extract the primary buffer. These patches seek to change that. All of the data
is already collected in the vmcore file; crash just isn't currently extracting
it.

I've split this changeset up into two pieces to address this. This first part
shouldn't lead to any change in functionality; it simply refactors the trace
extension so that the global instance is passed around as a parameter rather
than accessing it directly. That facilitates the second part, which locates all
of the available instances and extracts the data from each of them.

My testing has only included vmcores collected from 32-bit ARM systems, but I
don't believe I have made any assumptions about the architecture in my code.

Kyle Tomsic (2):
  Refactor trace extension to pass trace information as an argument
  Add support for multiple ftrace instances to trace extension

 extensions/trace.c | 430 +++++++++++++++++++++++++++++++++++++++++------------
 1 file changed, 333 insertions(+), 97 deletions(-)

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2.9.2