fix: guard LOG_D against null thread pointer in rt_ipc_list_resume()

[srpatcha]

Fix null pointer dereference in rt_ipc_list_resume()

Problem

rt_ipc_list_resume() in src/ipc.c dereferences thread in LOG_D("resume thread:%s\n", thread->parent.name) without checking if thread is RT_NULL. When rt_susp_list_dequeue() returns NULL (empty suspended list), this causes a kernel crash in debug builds.

Root Cause

The function correctly handles the NULL case by assigning thread = RT_NULL in the else branch (line 139), but the LOG_D call on line 143 unconditionally dereferences thread->parent.name before the function returns. This is only a problem in debug builds since LOG_D is compiled out in release mode, making it a latent bug that surfaces during development.

Fix

Wrapped the LOG_D call in a if (thread != RT_NULL) guard to prevent the null pointer dereference.

Testing

• Trigger an IPC resume on an empty suspended list with debug logging enabled.
• The system should no longer crash and should return RT_NULL gracefully.

Impact

Affects RT-Thread users debugging IPC operations. The crash only manifests in debug builds, making it particularly insidious during development.

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[github-actions]

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[github-actions]

📌 Code Review Assignment

🏷️ Tag: kernel

Reviewers: @GorrayLi @ReviewSun @hamburger-os @lianux-mm @wdfk-prog @xu18838022837

Changed Files (Click to expand)

• src/ipc.c

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📊 Current Review Status (Last Updated: 2026-04-18 05:47 CST)

• ⌛ @GorrayLi Pending Review
• ⌛ @ReviewSun Pending Review
• ⌛ @hamburger-os Pending Review
• ⌛ @lianux-mm Pending Review
• ⌛ @wdfk-prog Pending Review
• ⌛ @xu18838022837 Pending Review

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[BernardXiong]

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