Designing Syscalls for Extensibility

Explore the challenges and solutions of designing extensible syscalls in Linux through this conference talk from linux.conf.au 2020. Delve into the long-standing problem of safely extending syscall functionality while maintaining Linux's ABI guarantee. Examine various approaches attempted over the decades, their downsides, and the introduction of newer syscalls. Learn about recent alternative approaches to syscall extensibility, discussing trade-offs and potential future extensions. Cover topics including bitflags, fixed-size structures, extensible structures, rules, and examples. Discover improvements such as flag support and check fields, along with their implementation and caveats. Gain insights into the ideal world of syscall design and participate in a Q&A session to deepen your understanding of this crucial aspect of Linux kernel development.