Gdb Break Bus Error
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Bus Error (core Dumped) Linux
Join them; it only takes a minute: Sign up What is a bus error? up vote 156 down vote favorite 49 What does the "bus error" message mean, and how does it differ from a segfault? c unix
Bus Error Core Dumped C
segmentation-fault bus-error share|improve this question edited Oct 18 '15 at 10:44 Cool Guy 15.7k51952 asked Oct 17 '08 at 14:48 raldi 7,252216178 add a comment| 15 Answers 15 active oldest votes up vote 151 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 how to debug bus error 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 5,72322336 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 error. –Eloff Jul 14 '15 at 0:09 add a comment| up vote 58 down vote A segfault is accessing memory that you're not allowed to access. It's read-only, you don't have permission, etc... A bus error is trying to access memory that can't possibly be there. You've used
[x] Bug228 - bus error signal during
Bus Error (core Dumped) Centos
unaligned memory access... Summary: bus error signal during unaligned memory how to solve bus error in linux access... Status: RESOLVED WORKSFORME Alias: None Product: glibc Classification: Unclassified Component: libc (show other bus error core dumped in unix bugs) Version: unspecified Importance: P2 critical Target Milestone: --- Assignee: GOTO Masanori URL: Keywords: Depends on: Blocks: Reported: 2004-06-19 20:59 UTC by http://stackoverflow.com/questions/212466/what-is-a-bus-error Pawel Sikora Modified: 2004-06-23 07:24 UTC (History) CC List: 1 user (show) glibc-bugs See Also: Host: sparc64-pld-linux Target: sparc64-pld-linux Build: sparc64-pld-linux Last reconfirmed: Attachments Add an attachment (proposed patch, testcase, etc.) Note You need to log in before you can comment on or make changes to this bug. https://sourceware.org/bugzilla/show_bug.cgi?id=228 Description Pawel Sikora 2004-06-19 20:59:06 UTC # glibc-2.3.4-snap20040612, 4 x TI UltraSparc II (BlackBird) # gdb ./msgfmt (...) This GDB was configured as ""...Using host libthread_db library "/lib64/libthread_db.so.1". (gdb) set args -o pl.gmo pl.po (gdb) r Starting program: /home/users/support2/rpm/bus_error/msgfmt -o pl.gmo pl.po Program received signal SIGBUS, Bus error. 0xfffff80000416f28 in read () from /lib64/libc.so.6 (gdb) bt #0 0xfffff80000416f28 in read () from /lib64/libc.so.6 #1 0xfffff800003c5ac4 in _IO_file_read () from /lib64/libc.so.6 #2 0xfffff800003c4d68 in _IO_file_underflow () from /lib64/libc.so.6 #3 0xfffff800003c6b94 in _IO_default_uflow () from /lib64/libc.so.6 #4 0xfffff800003c69c4 in __uflow () from /lib64/libc.so.6 #5 0xfffff8000010f5cc in po_callback_comment_dispatcher () from /usr/lib64/libgettextsrc-0.14.1.so #6 0xfffff8000010fc08 in lex_end () from /usr/lib64/libgettextsrc-0.14.1.so #7 0xfffff8000010fddc in po_gram_lex () from /usr/lib64/libgettextsrc-0.14.1.so #8 0xfffff8000011136c in po_gram_parse () from /usr/lib64/libgettextsrc-0.14.1.so #9 0xfffff8000010e270 in po_scan () from /usr/lib64/libgettextsrc-0.14.1.so #10 0x00000000001071e8 in read_po_file_msgfmt (filename=0x7fffffffc9e "pl.po") at msgfmt.c:1710 #11 0x0000000000103ae8 in main (argc=4, argv=0x7
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 https://en.wikipedia.org/wiki/Bus_error operating system (OS) that a process is trying to access memory that the CPU cannot physically address: an invalid address for the address bus, hence the name. In modern use on most architectures these are much rarer than segmentation faults, which occur primarily due to memory access violations: problems in the logical address or permissions. On POSIX-compliant platforms, bus error 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 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 bus error (core 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. 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 addre