![]() The operating system executes at the highest level of privilege, and allows applications to request services via system calls, which are often initiated via interrupts. However, many applications need access to these components, so system calls are made available by the operating system to provide well-defined, safe implementations for such operations. For example, the rings model specifies multiple privilege levels under which software may be executed: a program is usually limited to its own address space so that it cannot access or modify other running programs or the operating system itself, and is usually prevented from directly manipulating hardware devices (e.g. The architecture of most modern processors, with the exception of some embedded systems, involves a security model. In most systems, system calls can only be made from userspace processes, while in some systems, OS/360 and successors for example, privileged system code also issues system calls. System calls provide an essential interface between a process and the operating system. This may include hardware-related services (for example, accessing a hard disk drive or accessing the device's camera), creation and execution of new processes, and communication with integral kernel services such as process scheduling. In computing, a system call (commonly abbreviated to syscall) is the programmatic way in which a computer program requests a service from the operating system on which it is executed. ![]() A high-level overview of the Linux kernel's system call interface, which handles communication between its various components and the userspace
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |