On 12/9/21 8:47 PM, Pengfei Xu wrote: > How about the following changes: > Will remove set_avx2_ymm() and will only check XSAVE_MASK_FP, XSAVE_MASK_OPMASK > and XSAVE_MASK_PKRU xstates after signal handling and process switch, First and foremost, the whole point of these tests is to ensure that the kernel is properly maintaining register state. Removing registers from the test moves *away* from the primary goal of this test. Second, you just listed three states there. Have you considered looking at whether those have the same problem as the XMM/YMM registers? Please do. Third (and I've also suggested this before), we should explicitly tell the compiler not to use the FPU registers. This is what the kernel does, and it's what allows us to, for instance, make function calls in the kernel without clobbering userspace content in XSAVE-managed registers. If we did that, then we would only have to worry about calls to things *outside* of the test program, like libc.
