Refactor Go-DI template generation to use location expressions

[grantseltzer]

What does this PR do?

This is a major refactor of the way Go-DI generates bpf programs. Instead
of generating bpf programs via templates for specific types, it breaks
down captures into basic building blocks of operations such as reading
from registers/stack, dereferencing, adding offsets, writing to output,
etc...

Templates are now these basic operations and as a result we can express
much more complex captures, such as pointers to pointers, slices of strings
or any combination of types that were previously supported.

Motivation

The previous iteration of Go-DI failed to be able to express complex types such as pointers to pointers. We didn't have a way of expressing any amount of multiple dereferences. This greatly increases the supported features/types for our customers to instrument.

Describe how to test/QA your changes

Run e2e tests

Possible Drawbacks / Trade-offs

Additional Notes

• There is still one fix I need to push to this branch. It involves the way length is captured and encoded for embedded slices and strings.
• I will be pushing more comments as well.
• Have linting issues to fix

[cit-pr-commenter]

Go Package Import Differences

Baseline: e49efd5
Comparison: 4a8f145

binary	os	arch	change
system-probe	linux	amd64	+1, -0 +golang.org/x/exp/rand
system-probe	linux	arm64	+1, -0 +golang.org/x/exp/rand

[agent-platform-auto-pr]

[Fast Unit Tests Report]

On pipeline 50860351 (CI Visibility). The following jobs did not run any unit tests:

Jobs:

• tests_deb-arm64-py3
• tests_deb-x64-py3
• tests_flavor_dogstatsd_deb-x64
• tests_flavor_heroku_deb-x64
• tests_flavor_iot_deb-x64
• tests_rpm-arm64-py3
• tests_rpm-x64-py3
• tests_windows-x64

If you modified Go files and expected unit tests to run in these jobs, please double check the job logs. If you think tests should have been executed reach out to #agent-devx-help

[cit-pr-commenter]

Regression Detector

Regression Detector Results

Metrics dashboard
Target profiles
Run ID: 13e555cf-101b-4f69-896d-722f4a6ba67a

Baseline: be4b703
Comparison: 6a06e28
Diff

Optimization Goals: ✅ No significant changes detected

Fine details of change detection per experiment

perf	experiment	goal	Δ mean %	Δ mean % CI	trials	links
➖	pycheck_lots_of_tags	% cpu utilization	+3.25	[-0.25, +6.74]	1	Logs
➖	quality_gate_logs	% cpu utilization	+0.65	[-2.35, +3.65]	1	Logs
➖	quality_gate_idle	memory utilization	+0.43	[+0.39, +0.48]	1	Logs bounds checks dashboard
➖	tcp_syslog_to_blackhole	ingress throughput	+0.31	[+0.25, +0.37]	1	Logs
➖	otel_to_otel_logs	ingress throughput	+0.03	[-0.64, +0.70]	1	Logs
➖	uds_dogstatsd_to_api_cpu	% cpu utilization	+0.02	[-0.72, +0.76]	1	Logs
➖	tcp_dd_logs_filter_exclude	ingress throughput	-0.00	[-0.01, +0.01]	1	Logs
➖	uds_dogstatsd_to_api	ingress throughput	-0.00	[-0.11, +0.11]	1	Logs
➖	file_to_blackhole_300ms_latency	egress throughput	-0.00	[-0.64, +0.64]	1	Logs
➖	file_to_blackhole_0ms_latency	egress throughput	-0.01	[-0.82, +0.80]	1	Logs
➖	file_to_blackhole_1000ms_latency_linear_load	egress throughput	-0.02	[-0.49, +0.45]	1	Logs
➖	file_tree	memory utilization	-0.04	[-0.19, +0.10]	1	Logs
➖	file_to_blackhole_500ms_latency	egress throughput	-0.06	[-0.83, +0.70]	1	Logs
➖	file_to_blackhole_100ms_latency	egress throughput	-0.10	[-0.89, +0.68]	1	Logs
➖	file_to_blackhole_1000ms_latency	egress throughput	-1.01	[-1.79, -0.23]	1	Logs
➖	quality_gate_idle_all_features	memory utilization	-1.22	[-1.34, -1.10]	1	Logs bounds checks dashboard
➖	basic_py_check	% cpu utilization	-2.35	[-6.16, +1.45]	1	Logs

Bounds Checks: ❌ Failed

perf	experiment	bounds_check_name	replicates_passed	links
❌	file_to_blackhole_0ms_latency	lost_bytes	8/10
❌	file_to_blackhole_300ms_latency	lost_bytes	8/10
❌	file_to_blackhole_100ms_latency	lost_bytes	9/10
✅	file_to_blackhole_0ms_latency	memory_usage	10/10
✅	file_to_blackhole_1000ms_latency	memory_usage	10/10
✅	file_to_blackhole_1000ms_latency_linear_load	memory_usage	10/10
✅	file_to_blackhole_100ms_latency	memory_usage	10/10
✅	file_to_blackhole_300ms_latency	memory_usage	10/10
✅	file_to_blackhole_500ms_latency	lost_bytes	10/10
✅	file_to_blackhole_500ms_latency	memory_usage	10/10
✅	quality_gate_idle	memory_usage	10/10	bounds checks dashboard
✅	quality_gate_idle_all_features	memory_usage	10/10	bounds checks dashboard
✅	quality_gate_logs	lost_bytes	10/10
✅	quality_gate_logs	memory_usage	10/10

Explanation

Confidence level: 90.00%
Effect size tolerance: |Δ mean %| ≥ 5.00%

Performance changes are noted in the perf column of each table:

• ✅ = significantly better comparison variant performance
• ❌ = significantly worse comparison variant performance
• ➖ = no significant change in performance

A regression test is an A/B test of target performance in a repeatable rig, where "performance" is measured as "comparison variant minus baseline variant" for an optimization goal (e.g., ingress throughput). Due to intrinsic variability in measuring that goal, we can only estimate its mean value for each experiment; we report uncertainty in that value as a 90.00% confidence interval denoted "Δ mean % CI".

For each experiment, we decide whether a change in performance is a "regression" -- a change worth investigating further -- if all of the following criteria are true:

1. Its estimated |Δ mean %| ≥ 5.00%, indicating the change is big enough to merit a closer look.

2. Its 90.00% confidence interval "Δ mean % CI" does not contain zero, indicating that if our statistical model is accurate, there is at least a 90.00% chance there is a difference in performance between baseline and comparison variants.

3. Its configuration does not mark it "erratic".

CI Pass/Fail Decision

✅ Passed. All Quality Gates passed.

• quality_gate_idle, bounds check memory_usage: 10/10 replicas passed. Gate passed.
• quality_gate_logs, bounds check lost_bytes: 10/10 replicas passed. Gate passed.
• quality_gate_logs, bounds check memory_usage: 10/10 replicas passed. Gate passed.
• quality_gate_idle_all_features, bounds check memory_usage: 10/10 replicas passed. Gate passed.