lccosy opened a new pull request, #19040: URL: https://github.com/apache/nuttx/pull/19040
Add NULL check for g_uart_devs[i] before accessing ->priv in arm_earlyserialinit() loop. When a USART is not enabled in defconfig, g_uart_devs[i] is NULL, causing a HardFault crash during early boot. The bug occurs because the original code only checked g_uart_devs[i]->priv without first verifying g_uart_devs[i] is not NULL. On Cortex-M4, NULL pointer dereference reads from Flash vector table (0x00000000 maps to 0x08000000), returning a function pointer that causes BusFault when written to. This fix matches the existing NULL check pattern used in arm_serialinit() at line 2835 of the same file. Tested on mplant-gd32f450 board with only USART5 enabled in defconfig. Before fix: HardFault at boot (IPSR=3, PC=0x080003e0) After fix: System boots normally to NSH Shell *Note: Please adhere to [Contributing Guidelines](https://github.com/apache/nuttx/blob/master/CONTRIBUTING.md).* ## Summary *Update this section with information on why change is necessary, what it exactly does and how, if new feature shows up, provide references (dependencies, similar problems and solutions), etc.* ## Impact *Update this section, where applicable, on how change affects users, build process, hardware, documentation, security, compatibility, etc.* ## Testing *This section should provide a detailed description of what you did to verify your changes work and do not break existing code.* *Please provide information about your host machine, the board(s) you tested your changes on, and how you tested. Logs should be included.* *For example, when changing something in the core OS functions, you may want to run the OSTest application to verify that there are no regressions. Changes to ADC code may warrant running the `adc` example. Adding a new uORB driver may require that you run `uorb_listener` to verify correct operation.* *Pure documentation changes can just be tested with `make html` (see docs) and verification of the correct format in your browser.* **_PRs without testing information will not be accepted. We will request test logs._** -- 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: [email protected] For queries about this service, please contact Infrastructure at: [email protected]
