jerpelea opened a new pull request, #15086: URL: https://github.com/apache/nuttx/pull/15086
## Summary fix regresion from https://github.com/apache/nuttx/pull/14881 reason: svc call may trigger hardfalt Background The origin of this issue is our desire to eliminate the function of storing "regs" in g_current_regs and instead utilize (*running_task)->xcp.regs for storage. The benefits of this approach include faster storage speed and avoiding multiple accesses to g_current_regs during context switching, thus ensuring that whether returning from an interrupt or an exception, we consistently use this_task()->xcp.regs Issue Encountered However, when storing registers, we must ensure that (running_task)->xcp.regs is invalid so that it can be safely overwritten. According to the existing logic, the only scenario where (running_task)->xcp.regs is valid is during restore_context. We must accurately identify this scenario. Initially, we used the condition (running_task)==NULL for this purpose, but we deemed this approach unsatisfactory as it did not align well with the actual logic. (running_task) should not be NULL. Consequently, we adopted other arch-specific methods for judgment, but due to special logic in some arch, the judgment was not accurate, leading to this issue. Solution: For armv6-m, we haven't found a more suitable solution, so we are sticking with (*running_task)==NULL. For armv7-m/armv8-m, by removing support for primask, we can achieve accurate judgment. PRIMASK is a design in armv6-m, that's why arm introduce BASEPRI from armv7-m. It's wrong to provide this option for armv7-m/armv8-m arch. ## Impact armv6-m armv7-m armv8-m ## Testing CI -- 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]
