Hi, My shadow stack tests start to have random shadow stack pointer corruption after v5.7 (excluding). The symptom looks like some locking issue or the kernel is confused about which CPU a task is on. In later tip/master, this can be triggered by creating two tasks and each does continuous pthread_create()/pthread_join(). If the kernel has max_cpus=1, the issue goes away. I also checked XSAVES/XRSTORS, but this does not seem to be an issue coming from there.
The tests I run take a long time to complete, and some commit points in bisect do not show failures right away. However, the issue can be more easily triggered after the point of: d77290507ab2 x86/entry/32: Convert IRET exception to IDTENTRY_SW Can anyone help me find places to look at? Thanks, Yu-cheng
