Access Bad Bus Error Memory
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Bus Error In Linux
Tags Users Badges Ask Question x Dismiss Join the Stack Overflow Community Stack Overflow is a community of 4.7 million programmers, just how to debug bus error like you, helping each other. Join them; it only takes a minute: Sign up What is a bus error? up vote 154 down vote favorite 49 What does the "bus error" message mean, and how does it differ sigbus error linux 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 7,226216178 add a comment| 15 Answers 15 active oldest votes up vote 149 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
Bus Error (core Dumped) Linux
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 5,68322336 51 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 error. –Eloff Jul 14 '15 at 0:09 add a comment| up vote 55 down vote A segfault is accessing memory that you're not allowed to access. It's read-only, you don't have permi
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Bus Error (core Dumped) C
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 gives a seg fault and stops for the first time and for the second time http://stackoverflow.com/questions/212466/what-is-a-bus-error 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 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 http://stackoverflow.com/questions/838540/bus-error-vs-segmentation-fault 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 instance, trying to read a multi-byte value (such as an int, 32-bits) from an odd address generated a bus error. Segmentation faults happen for instance when you do an access that violate the segmentation rules, i.e. trying to read or write memory that you don't own. share|improve
& 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 & http://www.unix.com/unix-for-dummies-questions-and-answers/3109-bus-error.html Answers Search Forums Show Threads Show Posts Tag Search Advanced Search Unanswered http://www.cplusplus.com/forum/beginner/3653/ 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 LivinFree Goober Extraordinaire Join Date: Jul 2001 Last Activity: 16 June 2011, bus error 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 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 bus error in 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 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
strcpy(newAccount, accountNum); and strcpy(newName, name); I am really bad with pointers. could anyone explain this to me. This is what i have so far #include