Not quite. The vDSO provides a general syscall-wrapper mechanism for certain types of system call interfaces. It also provides implementations of gettimeofday clock_gettime and 2 other system calls completely in userland and acts precisely as you've described.
Please see this[1] for a detailed explanation. For a shorter explanation, please see the vDSO man page[2]. Thanks for reading my blog post!
Please see this[1] for a detailed explanation. For a shorter explanation, please see the vDSO man page[2]. Thanks for reading my blog post!
[1]: https://blog.packagecloud.io/eng/2016/04/05/the-definitive-g... [2]: http://man7.org/linux/man-pages/man7/vdso.7.html