Use ENDBR instruction in amd64 coroutine on OpenBSD
When running on newer Intel processors supporting the feature,
OpenBSD enforces indirect branch tracking. Without this endbr64
instruction, jumps to the coroutine_transfer function result
in SIGILL on OpenBSD/amd64 when using such processors.
The OpenBSD Ruby ports have been using a patch similar to this
for the past two months.
From some research, cet.h has been supported by GCC for about
6 years and LLVM for about 4 years.
Use ENDBR instruction in amd64 coroutine on OpenBSD
When running on newer Intel processors supporting the feature,
OpenBSD enforces indirect branch tracking. Without this endbr64
instruction, jumps to the coroutine_transfer function result
in SIGILL on OpenBSD/amd64 when using such processors.
The OpenBSD Ruby ports have been using a patch similar to this
for the past two months.
From some research, cet.h has been supported by GCC for about
6 years and LLVM for about 4 years.