syscall64tbl

syscall64tbl is a data structure used in the Linux kernel for managing system call numbers. System calls are the interface between user-space applications and the operating system kernel. When a user-space program needs to request a service from the kernel, such as opening a file or creating a process, it executes a system call. Each system call is assigned a unique numerical identifier.

The syscall64tbl, specifically for the 64-bit x86 architecture, is an array that maps these system call numbers to the corresponding kernel functions. This table allows the kernel to efficiently dispatch the correct function based on the system call number provided by the user-space program. The structure and size of this table are crucial for system call performance and security. Changes to the system call interface, such as adding or removing system calls, necessitate modifications to this table. Modern Linux kernels use this mechanism to maintain a stable and efficient system call interface across different versions and hardware architectures.