Bus Error Unix C
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here for a quick overview of the site Help Center Detailed answers to any questions you might have Meta Discuss the workings and policies of this site About Us Learn more about linux bus error Stack Overflow the company Business Learn more about hiring developers or posting ads with solaris bus error us Stack Overflow Questions Jobs Documentation Tags Users Badges Ask Question x Dismiss Join the Stack Overflow Community Stack Overflow is oracle bus error a community of 4.7 million programmers, just like you, helping each other. Join them; it only takes a minute: Sign up What is a bus error? up vote 155 down vote favorite 49 What linux bus error core dumped 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 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
Bus Error In Linux Terminal
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 operating system can't back a virtual page with physical memory (e.g. low-memory conditions or out of huge pages when using huge page memory.) Typically mmap (and malloc) just reserve the virtual address space, and the kernel assigns the physical memory on demand (so called soft page faults.) Make a large enough malloc, and then write to enough of it and you'll get a bus err
program yourself, you can skip the rest of this section. For College-supported software, you can report the bug by contacting a consultant through olc or "mail staff".
Linux Bus Error Message
------------------------------------------------------------------------------- If the program displays this message: Bus error or Segmentation fault or how to solve bus error in linux Core dump ... then the program was trying to access a memory location outside its address space. The computer detected bus error c++ this problem and sent a signal to your program, which caused it to abort. Things that cause bus errors and segmentation violations are typically out-of-bounds array references and/or references through uninitialized or mangled http://stackoverflow.com/questions/212466/what-is-a-bus-error pointers. Look very closely in your program for bizarre things like that. A common example in C is: int c; scanf("%d", c); instead of the correct version: int c; scanf("%d", &c); An example from C++ is: int* p=new int[100]; cout<< p[100]; instead of the correct version: int* p=new int[100]; cout << p[99] (remember array referances in C and C++ start with 0 ) There are a number http://www.glue.umd.edu/afs/glue.umd.edu/system/info/olh/Utilities/Unix_answers/unix_bus_or_seg.html of methods for finding out where the program went out of bounds. One method is to use printf() statements to determine how far the program is getting before it crashes, and to print out the contents of interesting variables. A more sophisticated method is using 'dbx', a source level symbolic debugger. C and C++ programmers can also use 'gdb'. To learn about 'dbx', you can read the manual pages by using the 'man' command, as in: man dbx To learn about 'gdb', you can read the manual node in the 'xinfo' program, or using 'M-x info' in Emacs. If you need to debug your program, you may want to enable a core dump. Usually, those two messages above would also have "(core dumped)" by them, indicating that the program wrote an image of its current memory into a file called "core" in that directory. You might want to type 'fs lq' and find out how many blocks (kilobytes) you have available in your quota. Then you can type, say: limit coredumpsize 100 .. to limit your core dump size to 100K for your current login. BE CAREFUL not to let yourself go over quota, as you would then no
& Answers This forum is closed for new posts. Please post beginner questions to learn unix and learn linux in this forum UNIX for Beginners Questions & Answers Search Forums Show Threads Show Posts Tag Search Advanced Search Unanswered http://www.unix.com/unix-for-dummies-questions-and-answers/3109-bus-error.html Threads Find All Thanked Posts Go to Page... unix and linux commands - unix shell scripting Bus Error UNIX for Dummies Questions & Answers Thread Tools Search this Thread Display Modes #1 11-09-2001 https://docs.oracle.com/cd/E19455-01/806-1075/msgs-1097/index.html LivinFree Goober Extraordinaire Join Date: Jul 2001 Last Activity: 16 June 2011, 4:50 PM EDT Location: Portland, OR, USA Posts: 1,626 Thanks: 2 Thanked 15 Times in 13 Posts Bus Error This may belong in the C Programming bus error forum, but here goes anyway... What would cause a bus error? I searched google for a cause, but came up with some conflicting reports... Could it be caused by [lack of] disk space? A lot of the pages I found mentioned linking with the incorrect versions of the library. But in that case, would it compile correctly? Basically, I am curious as to why we had a job dump core on a bus error. It ran nearly to normal completion linux bus error time, then simply poo-pood. In the case that it may make a difference, it's a job that interfaces with an Oracle database on HP-UX 11. The things that had changed were that the process was recompiled, AND we were at 96% (df -k) on that disk... Not too important for me to know right now, but I am curious, and who wants to wait for developers to tell me what happened? Remove advertisements Sponsored Links LivinFree View Public Profile Find all posts by LivinFree #2 11-09-2001 Perderabo Unix Daemon (Administrator Emeritus) Join Date: Aug 2001 Last Activity: 26 February 2016, 12:31 PM EST Location: Ashburn, Virginia Posts: 9,931 Thanks: 64 Thanked 462 Times in 267 Posts The bus in question is the address buss and it contains an illegal value. This is almost always the result of dereferencing a pointer that contains an illegal value. Here is a program that, I think, will compile with every C or C++ compiler, but should cause a bus error when the second printf is attempted... Code: #ifdef __STDC__ #define PROTOTYPICAL #endif #ifdef __cplusplus #define PROTOTYPICAL #endif #include
has received a signal indicating that it attempted to perform I/O to a device that is restricted or that does not exist. This message is usually accompanied by a core dump, except on read-only file systems. Action Use a debugger to examine the core file and determine what program fault or system problem led to the bus error. If possible, check the program's output files for data corruption that might have occurred before the bus error. Technical Notes Bus errors can result from either a programming error or device corruption on your system. Some common causes of bus errors are: invalid file descriptors, unreasonable I/O requests, bad memory allocation, misaligned data structures, compiler bugs, and corrupt boot blocks. Previous: Broken pipeNext: "C" © 2010, Oracle Corporation and/or its affiliates