On Thu, Jun 23, 2016 at 10:52 AM, Linus Torvalds
<torvalds@linux-foundation.org> wrote:
>
> Ugh. Looking around at this, it turns out that a great example of this
> kind of legacy issue is the debug_mutex stuff.

Interestingly, the *only* other user of ti->task for a full
allmodconfig build of x86-64 seems to be

  arch/x86/kernel/dumpstack.c

with the print_context_stack() -> print_ftrace_graph_addr() -> task =
tinfo->task chain.

And that doesn't really seem to want thread_info either. The callers
all have 'task', and have to generate thread_info from that anyway.

So this attached patch (which includes the previous one) seems to
build. I didn't actually boot it, but there should be no users left
unless there is some asm code that has hardcoded offsets..

                 Linus