Fix breakage in bpf_probe_read from #196

Argument needs to be cast to u64, otherwise it is adding a whole pointer
stride.
Signed-off-by: Brenden Blanco <bblanco@plumgrid.com>

Add debug and fix the inline replace of kprobe args

The way in which args 1+ were being replaced in the C file was
fragile. Instead, assign the registers from ptregs into the function
arguments as the first statement(s) in the body of the function.
e.g.:
int sys_clone(struct ptregs *ctx, struct request *req) {
  // do something with req
}
becomes:
int sys_clone(struct ptregs *ctx, struct request *req) {
  req = ctx->di;
  // do something with req

Fixes: #192
Signed-off-by: Brenden Blanco <bblanco@plumgrid.com>

* Many times it is useful to print out the C file after the
  BFrontendAction has run.
  e.g.: BPF("file.c", debug=0x4)
Signed-off-by: Brenden Blanco <bblanco@plumgrid.com>

Change auto-loading behavior of trace_print

Since kprobe functions will have a different prototype than the kernel
symbols they are attaching to, require that the user prefix the trace
function with a kprobe__ name to denote intent. kretprobe__ prefix is
also supported.
Signed-off-by: Brenden Blanco <bblanco@plumgrid.com>

* As @brendangregg pointed out, users will probably assume that
  handily-named C functions that can be auto-loaded will be all the
  time, rather than just in the singleton case. This is pretty easy to
  implement, so changing the behavior.
Signed-off-by: Brenden Blanco <bblanco@plumgrid.com>

Support automatic kprobe event detection in common case

* In the simple case, a user only creates 1 C function to be used with
  kprobes. Detect this common case and don't require the user to repeat
  themselves by passing the fn_name to attach_kprobe().
  e.g.: BPF(text='int sys_clone(void *ctx) {/*do stuff*/}').trace_print()
Signed-off-by: Brenden Blanco <bblanco@plumgrid.com>

Suppress None return when trace_pipe drops lines

* When a "CPU: X Lost N events" line came on the trace_pipe,
  trace_fields would return None and cause exceptions in callers that do
  (a, b, ...) = b.trace_fields() type of calls. Instead, keep reading
  from trace_pipe when such messages come.

Fixes: #187
Signed-off-by: Brenden Blanco <bblanco@plumgrid.com>

Add BPF_HASH macro with variadic arguments

print_log2_hist() for #143

* Per suggestion in #149
Signed-off-by: Brenden Blanco <bblanco@plumgrid.com>

* Usage: BPF_HASH(tablename, key_type=u64, leaf_type=u64)
  2nd and 3rd arguments are optional in the C++ default argument style

Fixes: #135
Signed-off-by: Brenden Blanco <bblanco@plumgrid.com>

Shorten trace_readline_fields to trace_fields

* Per suggestion in #149
Signed-off-by: Brenden Blanco <bblanco@plumgrid.com>

simplify code using new features

Reorganize cmake, some cleanups and test fixes.

* After a kernel update, the binary of schedule function changed offset,
  and the attachment point updated. Since this is just a test case, pick
  a different function to test.
Signed-off-by: Brenden Blanco <bblanco@plumgrid.com>

* The c++ exception code was unused, now it is just c macro style
  "exceptions"
Signed-off-by: Brenden Blanco <bblanco@plumgrid.com>

Signed-off-by: Brenden Blanco <bblanco@plumgrid.com>

Update README.md and INSTALL.md, specfile dependencies

Signed-off-by: Brenden Blanco <bblanco@plumgrid.com>

* These files are required to build the test rpm
Signed-off-by: Brenden Blanco <bblanco@plumgrid.com>

* Add some runtime dependencies in INSTALL.md
* make and gcc are required at runtime, so add them to libbcc Requires:
Signed-off-by: Brenden Blanco <bblanco@plumgrid.com>

* Some changes to python API examples
* Reflect non-rc kernel availability in install doc
* Add binary rpm section to install doc
* Remove docker build instructions
Signed-off-by: Brenden Blanco <bblanco@plumgrid.com>

Fixes for when using clang/llvm as CC/CXX

Enhance check for presence of static-libstdc++

* Clang does not generate code to initialize the entire union when
  initializing a nested struct. This is the case for union bpf_attr.
  As a workaround, call memset explicitly.
Signed-off-by: Brenden Blanco <bblanco@plumgrid.com>

Signed-off-by: Brenden Blanco <bblanco@plumgrid.com>

* Fixes a link error on Ubuntu when static-libstdc++ is not installed.
Reported-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: Brenden Blanco <bblanco@plumgrid.com>

Include missed spec files in s/bpf/bcc/ rename