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Virtual Dynamic Shared Object
vDSO (virtual dynamic shared object) is a kernel mechanism for exporting a carefully selected set of kernel space A modern computer operating system usually uses virtual memory to provide separate address spaces or regions of a single address space, called user space and kernel space. This separation primarily provides memory protection and hardware prote ... routines to user space applications so that applications can call these kernel space routines in-process, without incurring the performance penalty of a mode switch (computing), mode switch from user mode to kernel mode that is inherent when calling these same kernel space routines by means of the system call interface. vDSO uses standard mechanisms for linker (computing), linking and loader (computing), loading i.e. standard Executable and Linkable Format (ELF) format. vDSO is a memory area allocated in user space which exposes some kernel functionalities. vDSO is dynamic allocation, dynamically allocated, offers impr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kernel Space
A modern computer operating system usually uses virtual memory to provide separate address spaces or regions of a single address space, called user space and kernel space. This separation primarily provides memory protection and hardware protection from malicious or errant software behaviour. Kernel space is strictly reserved for running a privileged operating system kernel, kernel extensions, and most device drivers. In contrast, user space is the memory area where application software and some drivers execute, typically with one address space per process. Overview The term user space (or userland) refers to all code that runs outside the operating system's kernel. User space usually refers to the various programs and libraries that the operating system uses to interact with the kernel: software that performs input/output, manipulates file system objects, application software, etc. Each user space process usually runs in its own virtual memory space, and, unless explici ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
C Standard Libraries
The C standard library, sometimes referred to as libc, is the standard library for the C programming language, as specified in the ISO C standard.ISO/IEC (2018). '' ISO/IEC 9899:2018(E): Programming Languages - C §7'' Starting from the original ANSI C standard, it was developed at the same time as the C POSIX library, which is a superset of it. Since ANSI C was adopted by the International Organization for Standardization, the C standard library is also called the ISO C library. The C standard library provides macros, type definitions and functions for tasks such as string manipulation, mathematical computation, input/output processing, memory management, and input/output. Application programming interface (API) Header files The application programming interface (API) of the C standard library is declared in a number of header files. Each header file contains one or more function declarations, data type definitions, and macros. After a long period of stability, three new ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Application Binary Interface
An application binary interface (ABI) is an interface exposed by software that is defined for in-process machine code access. Often, the exposing software is a library, and the consumer is a program. An ABI is at a relatively low-level of abstraction. Interface compatibility depends on the target hardware and the software build toolchain. In contrast, an application programming interface (API) defines access in source code which is a relatively high-level, hardware-independent, and human-readable format. An API defines interface at the source code level, before compilation, whereas an ABI defines an interface to compiled code. API compatibility is generally the concern for system design and of the toolchain. However, a programmer may have to deal with an ABI directly when writing a program in a multiple languages or compilers. A complete ABI enables a program that supports an ABI to run without modification on multiple operating systems that provide the ABI. The targe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Static Memory Allocation
In computer programming, a static variable is a variable (programming), variable that has been memory allocation, allocated "statically", meaning that its variable lifetime, lifetime (or "extent") is the entire run of the program. This is in contrast to shorter-lived automatic variables, whose storage is stack allocation, stack allocated and deallocated on the call stack; and in contrast to dynamic memory allocation, dynamically allocated objects, whose storage is allocated and deallocated in heap memory. Variable lifetime is contrasted with Scope (computer science), scope (where a variable can be used): "global" and "local" refer to scope, not lifetime, but scope often implies lifetime. In many languages, global variables are always static, but in some languages they are dynamic, while local variables are generally automatic, but may be static. In general, is the allocation of memory at compile time, before the associated program is executed, unlike dynamic memory allocation or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DWARF
Dwarf, dwarfs or dwarves may refer to: Common uses *Dwarf (folklore), a supernatural being from Germanic folklore * Dwarf, a human or animal with dwarfism Arts, entertainment, and media Fictional entities * Dwarf (''Dungeons & Dragons''), a short humanoid race * Dwarf (Middle-earth), a humanoid race in J. R. R. Tolkien's literature * Dwarf (''Warhammer''), a humanoid race * Dwarfs (''Discworld''), a race of characters * Dwarves (''Warcraft''), a short, strong race * Dwarves (Marvel Comics) * Seven Dwarfs Literature * ''The Dwarf'' (Cho novel), a 1978 novel by Cho Se-hui * ''The Dwarf'' (Lagerkvist novel), a 1944 novel by Pär Lagerkvist Other arts, entertainment, and media * ''Dwarfs?!'' (video game) *Dwarves (band) The Dwarves are an American punk rock band formed in Chicago, Illinois and based in San Francisco, California as of 2009.Gentile, John (2009)Interview: Blag Dahlia of the Dwarves", '' The A.V. Club'', April 13, 2009, retrieved February 7, 2010 ..., American p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IA-32
IA-32 (short for "Intel Architecture, 32-bit", commonly called ''i386'') is the 32-bit version of the x86 instruction set architecture, designed by Intel and first implemented in the i386, 80386 microprocessor in 1985. IA-32 is the first incarnation of x86 that supports 32-bit computing; as a result, the "IA-32" term may be used as a Metonymy, metonym to refer to all x86 versions that support 32-bit computing. Within various programming language directives, IA-32 is still sometimes referred to as the "i386" architecture. In some other contexts, certain iterations of the IA-32 ISA are sometimes labelled ''i486'', ''i586'' and ''i686'', referring to the instruction supersets offered by the i486, 80486, the P5 (microarchitecture), P5 and the P6 (microarchitecture), P6 microarchitectures respectively. These updates offered numerous additions alongside the base IA-32 set including X87, floating-point capabilities and the MMX (instruction set), MMX extensions. Intel was historically ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Computer Architectures
In computer science and computer engineering, computer architecture is a description of the structure of a computer system made from component parts. It can sometimes be a high-level description that ignores details of the implementation. At a more detailed level, the description may include the instruction set architecture design, microarchitecture design, logic design, and implementation. History The first documented computer architecture was in the correspondence between Charles Babbage and Ada Lovelace, describing the analytical engine. While building the computer Z1 in 1936, Konrad Zuse described in two patent applications for his future projects that machine instructions could be stored in the same storage used for data, i.e., the stored-program concept. Two other early and important examples are: * John von Neumann's 1945 paper, First Draft of a Report on the EDVAC, which described an organization of logical elements; and *Alan Turing's more detailed ''Proposed Electro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Syscall
In computing, a system call (syscall) is the programmatic way in which a computer program requests a service from the operating system on which it is executed. 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. System calls provide an essential interface between a process and the operating system. 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. For embedded systems, system calls typically do not change the privilege mode of the CPU. Privileges The architecture of most modern processors, with the exception of some embedded systems, involves a security model. For example, the '' rings'' model specifies multiple privilege levels under which software may be exe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glibc
The GNU C Library, commonly known as glibc, is the GNU Project implementation of the C standard library. It provides a wrapper around the system calls of the Linux kernel and other kernels for application use. Despite its name, it now also directly supports C++ (and, indirectly, other programming languages). It was started in the 1980s by the Free Software Foundation (FSF) for the GNU operating system. glibc is free software released under the GNU Lesser General Public License. The GNU C Library project provides the core libraries for the GNU system, as well as many systems that use Linux kernel, Linux as the kernel (operating system), kernel. These libraries provide critical APIs including ISO C11 (C standard revision), C11, POSIX.1-2008, Berkeley Software Distribution, BSD, OS-specific APIs and more. These APIs include such foundational facilities as open (system call), open, read (system call), read, write (system call), write, malloc, printf format string, printf, getaddrin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Address Space Layout Randomization
Address space layout randomization (ASLR) is a computer security technique involved in preventing exploitation of memory corruption vulnerabilities. In order to prevent an attacker from reliably redirecting code execution to, for example, a particular exploited function in memory, ASLR randomly arranges the address space positions of key data areas of a process, including the base of the executable and the positions of the stack, heap and libraries. When applied to the kernel, this technique is called ''kernel address space layout randomization'' (''KASLR''). History The Linux PaX project first coined the term "ASLR", and published the first design and implementation of ASLR in July 2001 as a patch for the Linux kernel. It is seen as a complete implementation, providing a patch for kernel stack randomization since October 2002. The first mainstream operating system to support ASLR by default was OpenBSD version 3.4 in 2003, followed by Linux in 2005. Benefits Addres ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
User Space
A modern computer operating system usually uses virtual memory to provide separate address spaces or regions of a single address space, called user space and kernel space. This separation primarily provides memory protection and hardware protection from malicious or errant software behaviour. Kernel space is strictly reserved for running a privileged operating system kernel, kernel extensions, and most device drivers. In contrast, user space is the memory area where application software and some drivers execute, typically with one address space per process. Overview The term user space (or userland) refers to all code that runs outside the operating system's kernel. User space usually refers to the various programs and libraries that the operating system uses to interact with the kernel: software that performs input/output, manipulates file system objects, application software, etc. Each user space process usually runs in its own virtual memory space, and, unless explici ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dynamic Allocation
In computer science, manual memory management refers to the usage of manual instructions by the programmer to identify and deallocate unused objects, or garbage. Up until the mid-1990s, the majority of programming languages used in industry supported manual memory management, though garbage collection has existed since 1959, when it was introduced with Lisp. Today, however, languages with garbage collection such as Java are increasingly popular and the languages Objective-C and Swift provide similar functionality through Automatic Reference Counting. The main manually managed languages still in widespread use today are C and C++ – see C dynamic memory allocation. Description Many programming languages use manual techniques to determine when to ''allocate'' a new object from the free store. C uses the malloc function; C++ and Java use the new operator; and many other languages (such as Python) allocate all objects from the free store. Determining when an object ought to be c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
