Bus Error
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challenged and removed. (July 2015) (Learn how and when to remove this template message) In computing, a bus error is a fault raised by hardware, notifying an operating system (OS) that a process is trying to access memory that the CPU cannot physically address: bus error 10 an invalid address for the address bus, hence the name. In modern use on most
Bus Error Linux
architectures these are much rarer than segmentation faults, which occur primarily due to memory access violations: problems in the logical address or permissions. bus error (core dumped) On POSIX-compliant platforms, bus errors usually result in the SIGBUS signal being sent to the process that caused the error. SIGBUS can also be caused by any general device fault that the computer detects, though a bus error
Bus Error Vs Segmentation Fault
rarely means that the computer hardware is physically broken—it is normally caused by a bug in a program's source code.[citation needed] Bus errors may also be raised for certain other paging errors; see below. Contents 1 Causes 1.1 Non-existent address 1.2 Unaligned access 1.3 Paging errors 2 Example 3 References Causes[edit] There are at least three main causes of bus errors: Non-existent address[edit] Software instructs the CPU to read or write a specific physical memory address. bus error 10 mac Accordingly, the CPU sets this physical address on its address bus and requests all other hardware connected to the CPU to respond with the results, if they answer for this specific address. If no other hardware responds, the CPU raises an exception, stating that the requested physical address is unrecognized by the whole computer system. Note that this only covers physical memory addresses. Trying to access an undefined virtual memory address is generally considered to be a segmentation fault rather than a bus error, though if the MMU is separate, the processor can't tell the difference. Unaligned access[edit] Most CPUs are byte-addressable, where each unique memory address refers to an 8-bit byte. Most CPUs can access individual bytes from each memory address, but they generally cannot access larger units (16 bits, 32 bits, 64 bits and so on) without these units being "aligned" to a specific boundary (the x86 platform being a notable exception). For example, if multi-byte accesses must be 16 bit-aligned, addresses (given in bytes) at 0, 2, 4, 6, and so on would be considered aligned and therefore accessible, while addresses 1, 3, 5, and so on would be considered unaligned. Similarly, if multi-byte accesses must be 32-bit aligned, addresses 0, 4, 8, 12, and so on would be considered aligned and therefore accessible, and all addresses in between would be considered
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Overflow the company Business Learn more about hiring developers or posting ads with us Stack Overflow Questions Jobs python bus error Documentation Tags Users Badges Ask Question x Dismiss Join the Stack Overflow Community Stack Overflow is a community of 4.7 million programmers, just like you, helping each other. Join https://en.wikipedia.org/wiki/Bus_error them; it only takes a minute: Sign up What is a bus error? up vote 155 down vote favorite 49 What does the "bus error" message mean, and how does it differ from a segfault? c unix segmentation-fault bus-error share|improve this question edited Oct 18 '15 at 10:44 Cool Guy 15.8k51952 asked Oct 17 '08 at 14:48 raldi 7,239216178 http://stackoverflow.com/questions/212466/what-is-a-bus-error add a comment| 15 Answers 15 active oldest votes up vote 150 down vote accepted Bus errors are rare nowadays on x86 and occur when your processor cannot even attempt the memory access requested, typically: using a processor instruction with an address that does not satisfy its alignment requirements. Segmentation faults occur when accessing memory which does not belong to your process, they are very common and are typically the result of: using a pointer to something that was deallocated. using an uninitialized hence bogus pointer. using a null pointer. overflowing a buffer. PS: To be more precise this is not manipulating the pointer itself that will cause issues, it's accessing the memory it points to (dereferencing). share|improve this answer edited Oct 17 '08 at 15:18 answered Oct 17 '08 at 15:12 bltxd 5,70322336 52 They aren't rare; I'm just at Exercise 9 from How to Learn C the Hard Way and already encountered one... –11684 Mar 26 '13 at 20:12 5 Another cause of bus errors (on Linux anyway) is when the operati
and End-of-Life ProductsCisco IOS Software Releases 12.1 MainlineTroubleshoot and AlertsTroubleshooting TechNotes Troubleshooting Bus Error Crashes Download Print Available Languages Download Options PDF (153.3 KB) View with Adobe Reader on a http://www.cisco.com/c/en/us/support/docs/ios-nx-os-software/ios-software-releases-121-mainline/7949-crashes-buserror-troubleshooting.html variety of devices ePub (111.5 KB) View in various apps on iPhone, iPad, Android, Sony Reader, or Windows Phone Mobi (Kindle) (129.9 KB) View on Kindle device or Kindle app on multiple devices Updated:Jun 16, 2016 Document ID:7949 ContentsIntroductionPrerequisitesRequirementsComponents UsedConventionsIdentifying Bus Error CrashesTroubleshooting Bus Error CrashesTroubleshooting Bus Error Crashes on 68000 Processor PlatformsTroubleshooting Bus Error Crashes on RISC Processor PlatformsSpecial Types of Bus Error CrashesTroubleshooting Techniques bus error for Bus Error Exception Boot LoopsCisco IOS Software Loaded Does Not Support Installed HardwareSoftware FailureMis-seated HardwareHardware FailureInformation to Collect if You Open a Service RequestRelated Information Introduction This document explains how to identify bus error crashes and how to troubleshoot those crashes depending on the type of processor you have in your Cisco router. Prerequisites Requirements Cisco recommends that you read Troubleshooting Router Crashes before proceeding with bus error 10 this document. Components Used The information in this document is based on these software and hardware versions: All Cisco IOS® software versions All Cisco routers Note:This document does not apply to Cisco Catalyst switches or MGX platforms. The information in this document was created from the devices in a specific lab environment. All of the devices used in this document started with a cleared (default) configuration. If your network is live, make sure that you understand the potential impact of any command. Conventions Refer to the Cisco Technical Tips Conventions for more information on document conventions. Identifying Bus Error Crashes The system encounters a bus error when the processor tries to access a memory location that either does not exist (a software error) or does not respond properly (a hardware problem). A bus error can be identified from the output of the show version command provided by the router if not power-cycled or manually reloaded. If you have the output of a show version or show technical-support command (from enable mode) from your Cisco device, you can use it to display potential issues and fixes. In order to use it, you must be a registered customer, be logged in,