josefx> Also making system calls from your own code varies between prohibited and badly supported on most OSes. Some see calls that didn't pass through the syst

josefx> Also making system calls from your own code varies between prohibited and badly supported on most OSes. Some see calls that didn't pass through the system libc as a security issue and will intercept them, while Linux may just silently corrupt your process memory if you try something fancy as the Go team had to find out. On Linux, making syscalls directly is fine. Good point about other platforms, but many people only care about Linux, for better or worse. And the author's last paragraph (quoted below) suggests using an alternate/static-linking-friendly libc, not making direct syscalls yourself. Presumably on platforms where those alternate libcs aren't available, you continue using the standard libc. ryanhileman> If you're running into process startup time issues in a real world scenario and ever actually need to do this, it might be worth your time to profile and try one of the alternative libc implementations (like musl libc or diet libc). IMHO, the Go vDSO problem [1] wasn't due to making direct syscalls but basically calling a userspace library without meeting its assumptions. I'd describe Linux's vDSO as a userspace library for making certain syscalls with less overhead. (If you don't care about the overhead, you can call them as you'd call any other syscall instead.) It assumed the standard ABI, in which there's a guard page as well as typically a generous amount of stack to begin with. Golang called into it from a thread that used Go's non-standard ABI with less stack space available (Go's own functions check the stack size on entry and copy the stack if necessary) and no guard page. On some Linux builds (with -fstack-check, apparently used by Gentoo Hardened ), it actually used enough stack to overflow. Without a guard page, that caused memory corruption. [1] https://github.com/golang/go/issues/20427 https://github.com/golang/go/issues/20427