nuttxpr commented on PR #15429: URL: https://github.com/apache/nuttx/pull/15429#issuecomment-2572609767
[**\[Experimental Bot, please feedback here\]**](https://github.com/search?q=repo%3Aapache%2Fnuttx+13552&type=issues) This PR summary is insufficient and lacks crucial information. Here's how it can be improved: **Improved Summary:** * **Why change is necessary:** The current implementation of RAM vectors lacks appropriate synchronization, potentially leading to data corruption or crashes if accessed concurrently. This change adds a small lock to protect `g_ram_vectors` during updates and accesses, ensuring data integrity and thread safety. * **What functional part of the code is being changed:** The RAM vector handling code in the ARMv6-M, ARMv7-M, and ARMv8-M architectures is being modified. Specifically, a lock is introduced to protect the `g_ram_vectors` global variable. * **How does the change exactly work:** A small, architecture-appropriate lock (e.g., a mutex or spinlock) is introduced. `arm_ramvec_initialize()` will initialize this lock. `arm_ramvec_attach()` will acquire the lock before modifying `g_ram_vectors`, and release it afterwards. Any other code accessing `g_ram_vectors` will also need to acquire the lock before access and release it afterward. * **Related NuttX Issue:** [Link to relevant NuttX issue if applicable. If there is no issue, consider creating one before the PR.] **Improved Impact:** * **Is new feature added?**: NO * **Is existing feature changed?**: YES - Improved thread safety for RAM vector handling. * **Impact on user**: NO - This change is internal and should not affect user application code directly. * **Impact on build**: NO * **Impact on hardware**: NO - This change affects the software handling of RAM vectors and has no direct impact on the hardware itself. * **Impact on documentation**: YES - The documentation should be updated to mention the added synchronization and any implications for users who directly access `g_ram_vectors` (although this is discouraged). * **Impact on security**: YES - This change improves the robustness and security of the system by preventing potential data corruption and system instability due to race conditions. * **Impact on compatibility**: NO - This change maintains backward compatibility. * **Anything else to consider?**: Consider the performance implications of the chosen locking mechanism. A spinlock might be suitable for short periods, while a mutex might be better for longer critical sections. Profiling should be done to assess the impact. **Improved Testing:** CI is insufficient. Provide specifics. * **Build Host(s):** [e.g., Linux (Ubuntu 20.04), x86_64, GCC 9.4.0] * **Target(s):** [e.g., QEMU-ARMv7-M (sim), STM32F4Discovery:default] **Testing logs before change:** ``` [Example: show output demonstrating the potential race condition or lack of synchronization, if possible. Even a theoretical example can be helpful.] Thread 1: Setting vector to 0x12345678 Thread 2: Setting vector to 0xABCDEF01 Result: Vector value corrupted - observed 0x1234EF01 ``` **Testing logs after change:** ``` [Example: show output demonstrating correct, synchronized behavior after the change.] Thread 1: Setting vector to 0x12345678 Thread 2: Setting vector to 0xABCDEF01 Result: Vector value correctly updated - observed 0xABCDEF01 (Thread 2's value, since it likely acquired the lock later) ``` By providing more detail and context, your PR will be much easier to review and understand, increasing the chances of it being accepted. Remember to replace the bracketed placeholders with your specific information. -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: commits-unsubscr...@nuttx.apache.org For queries about this service, please contact Infrastructure at: us...@infra.apache.org
