Fix for regression in modprobe script run

[kanchansenlaskar]

Description

#4152 this change had caused a regression where without waiting for hv_netvsc reload operation to complete and without waiting for the VM to come up, chown operation was attempted. This could be avoided by simply put a sudo true in the cat operation to handle mariner scenario. I had added a comment in that PR after it was merged and also informed the same to the author, yet it was not fixed, hence raised this PR.

Related Issue

Type of Change

• Bug fix
• New feature
• Breaking change
• Refactoring
• Documentation update

Checklist

• Description is filled in above
• No credentials, secrets, or internal details are included
• Peer review requested (if not, add required peer reviewers after raising PR)
• Tests executed and results posted below

Test Validation

Key Test Cases:
verify_cpu_offline_channel_add
verify_reload_hyperv_modules

Impacted LISA Features:

Tested Azure Marketplace Images:

Test Results

Image	VM Size	Result
		PASSED / FAILED / SKIPPED

[Copilot]

Pull request overview

This PR addresses a regression in the Modprobe.reload() flow by adjusting how the PID file is accessed after launching the modprobe_reloader.sh helper script, aiming to make the “script-run + PID polling” logic work reliably under sudo/root-owned file conditions.

Changes:

• Remove Chown usage/import in modprobe.py.
• Read the loop PID file via cat with sudo=True to avoid permission failures.

[Copilot]

The PR description template is still blank (no filled-in Description/Related Issue/Test Validation). Please add a short description of what regression is being fixed and include test results or a rationale for not running tests.

[github-actions]

✅ AI Test Selection — PASSED

3 test case(s) selected (view run)

Marketplace image: canonical 0001-com-ubuntu-server-jammy 22_04-lts-gen2 latest

	Count
✅ Passed	3
❌ Failed	0
⏭️ Skipped	0
Total	3

Test case details

Test Case	Status	Time (s)	Message
verify_uio_binding (lisa_0_0)	✅ PASSED	20.611
verify_gpu_rescind_validation (lisa_0_2)	✅ PASSED	14.290
verify_reload_hyperv_modules (lisa_0_1)	✅ PASSED	186.652

[github-actions]

✅ AI Test Selection — PASSED

2 test case(s) selected (view run)

Marketplace image: canonical 0001-com-ubuntu-server-jammy 22_04-lts-gen2 latest

	Count
✅ Passed	1
❌ Failed	0
⏭️ Skipped	1
Total	2

Test case details

Test Case	Status	Time (s)	Message
verify_bbr3_applies_to_live_tcp_flow (lisa_0_0)	⏭️ SKIPPED	11.630	skipped: bbr3 is not available in net.ipv4.tcp_available_congestion_control. CONFIG_TCP_CONG_BBR3 is not enabled in kern
verify_reload_hyperv_modules (lisa_0_1)	✅ PASSED	187.496

[Copilot]

Pull request overview

Copilot reviewed 1 out of 1 changed files in this pull request and generated 2 comments.

[Copilot]

Consider linking the related issue for traceability (e.g., Fixes #...). The PR description's Related Issue section is currently empty.

Suggested change

	pid = cat.read(
	loop_process_pid_file_name, force_run=True, sudo=True
	).strip()
	raw_pid = cat.read(
	loop_process_pid_file_name, force_run=True, sudo=True
	).strip()
	pid = str(int(raw_pid))

[Copilot]

Please populate the PR's Test Validation/Test Results (images, VM sizes, and pass/fail) before approval. This change affects module reload behavior and should be validated on at least one Azure Linux (Mariner) image where the regression was observed.

[LiliDeng]

@bhagyapathak please help test against mariner.