Comment by zbowling

And go is wrong for doing that, at least on Linux. It bypasses optimizations in the vDSO in some cases. On Fuchsia, we made direct syscalls not through the vDSO illegal and it was funny the hacks to go that required. The system ABI of Linux really isn't the syscall interface, its the system libc. That's because the C ABI (and the behaviors of the triple it was compiled for) and its isms for that platform are the linga franca of that system. Going around that to call syscalls directly, at least for the 90% of useful syscalls on the system that are wrapped by libc, is asinine and creates odd bugs, makes crash reporters heuristical unwinders, debuggers, etc all more painful to write. It also prevents the system vendor from implementing user mode optimizations that avoid mode and context switches when necessary. We tried to solve these issues in Fuchsia, but for Linux, Darwin, and hell, even Windows, if you are making direct syscalls and it's not for something really special and bespoke, you are just flat-out wrong.