bd9e0f5df6
For signal send, copyout from the user FPU save area directly. For sigreturn, we are in sleepable context and can do temporal allocation of the transient save area. We cannot copying from userspace directly to user save area because XSAVE state needs to be validated, also partial copyins can corrupt it. Requested by: jhb Reviewed by: jhb, markj Tested by: pho Sponsored by: The FreeBSD Foundation MFC after: 1 week Differential revision: https://reviews.freebsd.org/D31954