documentation typos

Fix segfault in ~BPFModule on syntax error

~BPFModule was segfaulting because tables_ was an empty pointer. The
pointer is valid only for valid compilations. Add a test as well.
Signed-off-by: Brenden Blanco <bblanco@plumgrid.com>

contributing scripts guide

Reorder P4 struct key initializers and blocks

The basic_routing.p4 program was failing verification due to missed map
key initializers in some paths. Put the goto label at the head of the
block and add a " = {}" for each key declaration inside the block.
Signed-off-by: Brenden Blanco <bblanco@plumgrid.com>

use __builtin_memcpy() instead of unrolled loop

also remove tab and unused import
Signed-off-by: Alexei Starovoitov <ast@fb.com>

Added cachestat tool

Added .txt to exmaple file to allow link to work

duplicate file

duplicate of .txt version

  Author:    allan mcaleavy <allan.mcaleavy@gmail.com>

offwaketime

Update test_dump_func to be python3 compatible

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

gethostlatency

bashreadline

more strlen examples

Add uprobe strlen histogram example

This example traces all calls to libc's strlen(). The program is attached as a
retprobe, therefore giving access to the resulting string length. The value is
kept in a log2 histogram that is printed to console once per second.

Example:
```
$ sudo ./strlen_hist.py
22:12:51
     strlen return:      : count     distribution
         0 -> 1          : 2041     |****************                        |
         2 -> 3          : 1120     |********                                |
         4 -> 7          : 3300     |**************************              |
         8 -> 15         : 4995     |****************************************|
        16 -> 31         : 2130     |*****************                       |
        32 -> 63         : 562      |****                                    |
^C
```
Signed-off-by: Brenden Blanco <bblanco@plumgrid.com>

Uprobe support

Use the full path invocation of objdump in both places.

Add a docstring for the variants of attach_retprobe.
Signed-off-by: Brenden Blanco <bblanco@plumgrid.com>

The calculation of function address in non-shared libraries was
incorrect. Fix it.
Signed-off-by: Brenden Blanco <bblanco@plumgrid.com>

This adds a similar set of functions to kprobes for userspace probes.
The calling convention is different, however, since the user must
provide a library/binary name and function symbol or address. Add two
simple test cases for both.

I don't see an easy way in this api to add auto-loading support, as in
kprobe functions that start with "kprobe__". Such niceties can come
later.
Signed-off-by: Brenden Blanco <bblanco@plumgrid.com>

The base calling convention for uprobes is the same as kprobes, but just
the path in debug/tracing/ is slightly different. Add a new API for this
and slightly refactor the code.
Signed-off-by: Brenden Blanco <bblanco@plumgrid.com>

wakeuptime

Add decode() to ascii string in offcputime.py

Fixes: #318
Signed-off-by: Brenden Blanco <bblanco@plumgrid.com>

Updates to use cmake GLOB and libbcc.so.0 in python init