Change Details

Rather than trying to blacklist which bits userland can't write to via sigreturn() or setcontext(), only permit changes to bits in the user-writable USTATUS register that shadows SSTATUS.

Rather than trying to blacklist which bits userland can't write to via sigreturn() or setcontext(), only permit changes to whitelisted bits. - Permit arbitrary writes to bits in the user-writable USTATUS register that shadows SSTATUS. - Ignore changes in write-only bits maintained by the CPU. - Ignore the user-supplied value of the FS field used to track floating point state and instead set it to a value matching the actions taken by set_fpcontext().

Rather than trying to blacklist which bits userland can't write to via sigreturn() or setcontext(), only permit changes to bits in thewhitelisted user-writable USTATUS register that shadows SSTATUSbits. - Permit arbitrary writes to bits in the user-writable USTATUS register that shadows SSTATUS. - Ignore changes in write-only bits maintained by the CPU. - Ignore the user-supplied value of the FS field used to track floating point state and instead set it to a value matching the actions taken by set_fpcontext().