apps/examples/watchdog: Improve help message and add hang test

[seokhun-eom24]

1. apps/examples/watchdog: Improve help message and parameter validation

Improve help message to explain parameters and their usage.
Add parameter validation to prevent invalid values in integer overflow and argument string length overflow.

[Help Message]

TASH>>Usage:
  watchdog <command> [arguments]

Commands:
  help
      Show this help message

  expire [timeout_ms] [status_period_ms]
      Start watchdog expiration test
      timeout_ms        Watchdog timeout in milliseconds
                        Default: 30001 ms
      status_period_ms  Status print interval in milliseconds
                        0 disables periodic status printing
                        Default: 0 ms

  keepalive
      Send keepalive signal to watchdog

  status
      Show current watchdog status

  stop
      Stop watchdog

  pause
      Pause watchdog

  resume
      Resume watchdog

  pause_resume [pause_ms] [resume_ms]
      Run one watchdog pause/resume test sequence
      pause_ms          Pause duration in milliseconds
                        Default: 1000 ms
      resume_ms         Resume duration in milliseconds
                        Default: 200 ms

Examples:
  watchdog expire
  watchdog expire 30001 1000
  watchdog pause_resume
  watchdog pause_resume 1000 200

Notes:
  pause_resume timeout = pause_ms * 10

2. apps/examples/watchdog: Add watchdog hang test in flat build

Implemented a new watchdog hang command to test watchdog operation in a hang situation.
This test is only available on flat build.
It uses sched_lock and enter_critical_section to make hang situation.

[seokhun-eom24]

Automated nightly Codex PR review
PR: #7331 — apps/examples/watchdog: Improve help message and add hang test
PR URL: #7331
GitHub updatedAt: 2026-05-11T07:20:12Z
Refreshed (UTC): 2026-05-11 17:42:15 UTC
Refreshed (KST): 2026-05-12 02:42:15 KST
Comment model: single evolving Codex-authored PR comment

PR #7331 — apps/examples/watchdog: Improve help message and add hang test

This review done by codex. AI reviews can be inaccurate.
UTC: 2026-05-11 17:41 UTC
KST (UTC+9): 2026-05-12 02:41 KST

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Repository: Samsung/TizenRT

Base → Head: master → pr/7331

HEAD Commit: ab95a2ecd3a71415f739fbc38ac5dbd48a4cf993

Scope: apps/examples/watchdog/Kconfig, apps/examples/watchdog/watchdog_main.c

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Review Summary

Category	Status
Build / Compile Status	⚠️ Static review only; no target build was run in this unattended pass
Functional Correctness	✅ No blocking issue found in the changed command parsing, argument validation, or hang-test control flow
Validation Coverage	⚠️ PR does not add an automated or documented target validation log for the new FLAT-only hang path

Final Verdict: 💬 Comment

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Must-Fix Issues

No blocking issues found.

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Nice-to-Have Improvements

1. Add explicit validation evidence for the FLAT-only hang command

Item	Details
Location	apps/examples/watchdog/watchdog_main.c:463
Severity	Low
Type	Validation

Problem
The PR introduces a new watchdog hang command that deliberately locks scheduling and enters a critical section in FLAT builds, but the PR does not include a target build/run log showing that both the FLAT implementation and the non-FLAT rejection path were exercised.

Impact

• The static control flow looks intentional, but merge confidence still depends on board-level behavior because the success case is a hardware reset rather than a normal process return.
• The unsupported non-FLAT path is present at apps/examples/watchdog/watchdog_main.c:463, so it is useful to document that protected/kernel builds still present a controlled error instead of pulling in FLAT-only headers or symbols.

Recommended Action

• Add the validation commands and observed output to the PR description or a follow-up note.
• Cover at least one FLAT target where watchdog hang [timeout_ms] resets as expected and one non-FLAT target where the command prints watchdog: hang is only supported in FLAT build.

Example Validation Matrix

Area	Example Target / Check	Result
FLAT hang path	Enable CONFIG_EXAMPLES_WATCHDOG=y, run watchdog hang 40000, confirm watchdog reset reason	Not Run
Non-FLAT compatibility	Enable the example in a protected/kernel configuration, run watchdog hang	Not Run
Existing commands	watchdog expire, watchdog pause_resume, watchdog help	Not Run

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Notable Improvements

✔ Safer sleep argument bounds

• watchdog_validate_sleep_ms() at apps/examples/watchdog/watchdog_main.c:134 rejects zero values where they would make the command meaningless and rejects values that would overflow the ms * 1000 conversion before usleep().

✔ FLAT-only hang logic is isolated

• The FLAT-only includes are guarded at apps/examples/watchdog/watchdog_main.c:33, and the non-FLAT watchdog_run_hang() stub at apps/examples/watchdog/watchdog_main.c:463 keeps non-FLAT builds from depending on sched_lock() or enter_critical_section().

✔ Help output now describes command arguments

• The expanded help at apps/examples/watchdog/watchdog_main.c:88 documents defaults, argument meaning, and examples for the watchdog operations, which makes the example easier to run correctly from TASH.

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Final Assessment

Must-Fix Summary

• No blocking issues were found during static review.

Nice-to-Have Summary

• Add target validation evidence for the new hardware-reset hang scenario and the non-FLAT unsupported path.

Residual Risk / Test Gap

• Static review only; no dbuild target build or board-level watchdog reset test was run in this unattended review.
• Hardware watchdog behavior, reset reason capture, and command output were not validated on target hardware.

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Final Verdict

💬 Comment

The PR is reasonable to continue, with no merge-blocking issue found in the reviewed diff. The main remaining gap is validation evidence for the new FLAT-only hang command because its expected success condition is a hardware watchdog reset.