[Crash-utility] Extensions: Dump log buffer of Intel Processor Trace

[Andi Kleen]

On Tue, Jan 05, 2016 at 05:31:11PM +0900, Takao Indoh wrote:
> Hi Dave,
> 
> The attached files are extension module to dump log buffer of Intel
> Processor Trace from vmcore. Please consider placing this in the
> extensions page.
> 
> [Overview of PT]
> PT(Processor Trace) is a new feature of Intel CPU "Broadwell", it
> captures information about program execution flow.[1]
> 
> Once Intel PT is enabled, the events which change program flow, like
> branch instructions, exceptions, interruptions, traps and so on are
> logged in the memory. This is very useful for debugging because we can
> know the detailed behavior of software.

Thanks for working on this. Yes that's very useful.

I still would prefer if the interface to the kernel was a bit cleaner,
but I guess that's what we have.

Also of course the user interface would need to be improved to actually
dump instructions and function calls from the trace, perhaps similar to
how sptdecode im simple-pt does it (but using the crash callbacks to
access all memory)

-Andi
-- 
ak at linux.intel.com -- Speaking for myself only.