Add option to change kernel build search paths

Include all of the paths in the build/ directory when kernel headers are
split.
Signed-off-by: Brenden Blanco <bblanco@plumgrid.com>

Some linux distributions structure the /lib/modules directories
differently, causing complexities. Add cmake overrides to be able to
compile different behavior.

If your distro sets up `/lib/modules/$(uname -r)/{source,build}` with
header files split between the two (debian does this), then add
-DBCC_KERNEL_HAS_SOURCE_DIR=1 to the cmake command line.

If your distro just has something other than build/, but things are
still in one subdirectory, then add -DBCC_KERNEL_MODULES_SUFFIX=foo to
the cmake command line.

Also, fix one implicit declaration warning introduced by the new
bpf_get_stackid() helper.

Fixes: #397
Signed-off-by: Brenden Blanco <bblanco@plumgrid.com>

[RFC] Basic implementation of stacktrace table

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

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

This is the initial implementation of bpf_get_stackid with python
helpers. This doesn't expose the different methods of calling
(kernel/user, fast, or reuse).
Signed-off-by: Brenden Blanco <bblanco@plumgrid.com>

Fix stacksnoop PID filter

The function FILTER is injected into (trace_stack()) returns void, not int.

Move cc/*py tests to python subdir and introduce c standalone test binary

This creates a new static library target for bcc. Add one trivial c test
case that links against it.
Signed-off-by: Brenden Blanco <bblanco@plumgrid.com>

They didn't quite make sense where they were. At one point 'cc' meant
compiler, and yes they were testing the compiler. Now lets use the
convention that different tests/ subdirectories test different bindings
(c, python, other).
Signed-off-by: Brenden Blanco <bblanco@plumgrid.com>

Update headers with 4.5+ features

Pull in bpf.h from upstream, and update helpers accordingly.
Signed-off-by: Brenden Blanco <bblanco@plumgrid.com>

INSTALL.md: Fix path for example and some small clarifications

Add v6 headers to proto.h

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

tools map

Remove use of update() in funccount

Hash map updates are not safe in recursive context. Change the
implementation of funccount to be read-only by converting
lookup_or_init() to lookup(). When run in interval mode, zero the counts
table instead of clearing it.
Signed-off-by: Brenden Blanco <bblanco@plumgrid.com>

Add a helper to translate from kernel name to symbol. As part of this,
slightly refactor the ksym globals (which are internal implementation
and not part of the api) so that there is one array of tuples instead of
two arrays.
Signed-off-by: Brenden Blanco <bblanco@plumgrid.com>

It is sometimes useful to zero out the entries of table without erasing
the keys. Add a zero() function to make this easy.
Signed-off-by: Brenden Blanco <bblanco@plumgrid.com>

Enforce limit of 1000 open [uk]probes

The number of open probes has bitten users already, so lets enforce a
limit with a meaningful(ish) message.
Signed-off-by: Brenden Blanco <bblanco@plumgrid.com>

Prepare debian changelog for v0.1.8 tag

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

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

Prepare deb build for nightly target

Add incremental release numbering for deb targets.
Tweak rpm release numbering as well.
Signed-off-by: Brenden Blanco <bblanco@plumgrid.com>

Fix ubuntu kernel path typo is INSTALL.md

Update rpm build scripts and README

Print traceback only if verbose mode was requested

trace: trace function execution with custom format strings and filters

Remove the unused Dockerfiles.

Create two flavors of spec files, one which includes steps to build
clang from source and link against it, and one which assumes clang is
already available and just builds bcc. The former is more appropriate
for official packaging, the latter for nightly and quick builds.

Also, introduce a numbering scheme for nightly rpm files. The format
will be:
`libbcc-$latest_git_tag-g$latest_git_hash.x86_64.rpm`
as in:
`libbcc-0.1.7-g73c4d1a.x86_64.rpm`

Update the INSTALL.md to mention the RPMs
Signed-off-by: Brenden Blanco <bblanco@plumgrid.com>