V2 add syscall tracepoints

hi,

The following is an implementation of Frederic's syscall tracer on top of
tracepoints. It adds the ability to toggle the entry/exit of each syscall
via the standard events/syscalls/syscall_blah/enable interface. The
implementation is done by adding 2 tracepoints. One on entry and one for exit.

I've tried to address all of the comments from the last posting...updates include:
-2/7: make arch_init_ftrace_syscalls static, removed locking, make patch bi-sectable
-3/7: rename DECLARE_TRACE_REG as DECLARE_TRACE_WITH_CALLBACK
-4/7: make mutex and counter static
-7/7: add event tracing for syscalls that take no args

thanks,

-Jason

 arch/x86/include/asm/ftrace.h |    4 +-
 arch/x86/kernel/ftrace.c      |   31 +++++---
 arch/x86/kernel/ptrace.c      |    6 +-
 include/linux/syscalls.h      |   75 +++++++++++++++++-
 include/linux/tracepoint.h    |   29 ++++++-
 include/trace/syscall.h       |   37 +++++++---
 kernel/trace/trace_events.c   |   29 +++++---
 kernel/trace/trace_syscalls.c |  172 +++++++++++++++++++----------------------
 kernel/tracepoint.c           |   38 +++++++++
 9 files changed, 289 insertions(+), 132 deletions(-)