Don't uvm_useracc the user sigcontext in sys_sigreturn and then access the user addresses directly from the kernel. copyin is faster and can correctly deal properly with mappings that uvm_useracc thinks are correct but will fault anyway (to figure out how to generate such mappings is left as en excercise for the reader).
Don't uvm_useracc the user sigcontext in sys_sigreturn and then access
the user addresses directly from the kernel. copyin is faster and can
correctly deal properly with mappings that uvm_useracc thinks are
correct but will fault anyway (to figure out how to generate such
mappings is left as en excercise for the reader).

Blatantly stolen from art@'s similar fix to sparc.

orumin/openbsd-efivars,orumin/openbsd-efivars,orumin/openbsd-efivars,orumin/openbsd-efivars