Merge branch 'core/stacktrace' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'core/stacktrace' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
generic-ipi: powerpc/generic-ipi tree build failure
stacktrace: fix build failure on sparc64
stacktrace: export save_stack_trace[_tsk]
stacktrace: fix modular build, export print_stack_trace and save_stack_trace
backtrace: replace timer with tasklet + completions
stacktrace: add saved stack traces to backtrace self-test
stacktrace: print_stack_trace() cleanup
debugging: make stacktrace independent from DEBUG_KERNEL
stacktrace: don't crash on invalid stack trace structs