Linux System Calls
3 days ago
- #Kernel
- #Linux
- #System Calls
- Linux has a stable kernel-userspace interface, unlike other operating systems.
- Programs usually interface with the kernel through libraries like libc, but Linux allows direct system calls.
- Linux guarantees stability at the binary interface level, making it a platform to build upon without dependencies.
- System calls in Linux use processor instructions to switch to kernel mode, with parameters passed in registers.
- The system call number (NR) indexes a function table in the kernel.
- Linux's system call calling convention is stable and programming language agnostic.
- Implementing a system call involves placing parameters in registers and executing a system call instruction.
- Example provided for x86_64 architecture using the syscall instruction.