An errata patch for the libc library on the mips64 architecture has been released for OpenBSD 6.8 and OpenBSD 6.9.
On mips64, the strchr/index/strrchr/rindex functions in libc handled signed characters incorrectly. Source code patches can be found on the respective errata pages: https://www.openbsd.org/errata68.html https://www.openbsd.org/errata69.html
