A 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 bus error c++ address: an invalid address for the address bus, hence the name. In modern use on
Bus Error Linux
most architectures these are much rarer than segmentation faults, which occur primarily due to memory access violations: problems in the logical address or bus error fortran permissions. 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 Core Dumped
bus error 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 bus error mac memory address. 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 bet
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Badges Ask Question x Dismiss Join the Stack Overflow Community Stack Overflow is a community of 4.7 million programmers, just like you, helping python bus error each other. Join them; it only takes a minute: Sign up Bus error vs Segmentation fault up vote 25 down vote favorite 8 Difference between a bus error and a segmentation fault? Can it happen that a program https://en.wikipedia.org/wiki/Bus_error gives a seg fault and stops for the first time and for the second time it may give a bus error and exit ? c share|improve this question edited May 2 '12 at 12:04 casperOne 57.9k10125202 asked May 8 '09 at 6:56 Thunderboltz 6203915 add a comment| 6 Answers 6 active oldest votes up vote 34 down vote accepted On most architectures I've used, the distinction is that: a SEGV is caused when you access memory http://stackoverflow.com/questions/838540/bus-error-vs-segmentation-fault you're not meant to (e.g., outside of your address space). a SIGBUS is caused due to alignment issues with the CPU (e.g., trying to read a long from an address which isn't a multiple of 4). share|improve this answer answered May 8 '09 at 7:06 paxdiablo 487k1179691416 10 Memory mapped files can also generate SIGBUS. –bk1e May 8 '09 at 16:06 on arm SIGBUS can occur if you read a float from an address that is not 4 byte aligned –shoosh Mar 30 at 7:29 shoosh, I'm pretty certain that's covered by my second bullet point. –paxdiablo Mar 30 at 13:28 add a comment| up vote 11 down vote SIGBUS will also be raised if you mmap() a file and attempt to access part of the mapped buffer that extends past the end of the file, as well as for error conditions such as out of space. If you register a signal handler using sigaction() and you set SA_SIGINFO, it may be possible to have your program examine the faulting memory address and handle only memory mapped file errors. share|improve this answer answered May 8 '09 at 16:04 bk1e 17.9k43760 add a comment| up vote 5 down vote For instance, a bus error might be caused when your program tries to do something that the hardware bus doesn't support. On SPARCs, for in
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 variety of http://www.cisco.com/c/en/us/support/docs/ios-nx-os-software/ios-software-releases-121-mainline/7949-crashes-buserror-troubleshooting.html devices ePub (111.5 KB) View in various apps on iPhone, iPad, Android, Sony Reader, https://www.quora.com/What-is-the-difference-between-a-bus-error-and-a-segmentation-fault 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 for Bus Error Exception Boot bus error 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 this document. Components Used The information in a bus error 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, and have JavaScript enabled. Router uptime is 2 days, 21 hours, 30 minute
the difference between a bus error and a segmentation fault?UpdateCancelPromoted by Metavision.comStay on top of the latest augmented reality (AR) happeningsPokémon GO barely touched on AR's potential. Read these AR-related sites to keep up with the industryLearn More at Metavision.comAnswer Wiki2 Answers Abhinav Jangda, Computer Science Reseacher at IISc, Glasgow and CMU Research InternWritten 145w agoBus Error occurs when Processor cannot attempt to access the memory area requested.Segmentation Fault occurs when Processor tries to access a memory area which doesn't belongs to current process.451 Views · View UpvotesRelated QuestionsMore Answers BelowWhat is the difference between bus error and segmentation core dumped and where do they both exist?593 ViewsIs there any difference between segmentation fault and dangling pointer?2,645 ViewsWhy is this showing me segmentation fault?1,409 ViewsWhat is the difference between a segmentation fault and core dump?575 ViewsWhat are some of the best/must read articles for debugging segmentation faults in C++?515 Views Shravan Kumar, Writes code for foodWritten 97w agoOn most architectures I've used, the distinction is that:a SEGV is caused when you access memory you're not meant to (e.g., outside of your address space).a SIGBUS is caused due to alignment issues with the CPU (e.g., trying to read a long from an address which isn't a multiple of 4).Reference : Aka Stack Overflow336 Views · View UpvotesView More AnswersRelated QuestionsWhy do I get Segmentation fault error when executing my code?2,729 ViewsWhy am I getting a segmentation fault error in the following code?911 ViewsWhat is a segmentation fault?5,746 ViewsHow do I troubleshoot segmentation fault problems?2,769 ViewsWhy can't I initialize a pointer to NULL in my binary tree implementation code? How can I fix the segmentation fault error in my code?1,376 ViewsWhat is the difference between a syntax error, type error and end error?383 ViewsWhy is my code showing segmentation fault?1,738 ViewsLearning to Program: What is the difference between run time error and compilation error?2,903 ViewsWhat is the difference between a compile-time (static) error and a (dynamic) run-time