>My program calls malloc(x) several times, where x is never negative nor >0. But on one particular malloc() it always crashes. > >running my program with valgrind gives me the following hints: > > >- --15446-- VALGRIND INTERNAL ERROR: Valgrind received a signal 11 >(SIGSEGV) - exiting >- --15446-- si_code=1; Faulting address: 0x2D11153860; sp: >0x40317bdd0 > >valgrind: the 'impossible' happened: > Killed by fatal signal >==15446== at 0x38032A94: unlinkBlock (m_mallocfree.c:245) >==15446== by 0x3803453D: vgPlain_arena_malloc (m_mallocfree.c:1381) >==15446== by 0x3800292E: vgMemCheck_new_block >(mc_malloc_wrappers.c:201) >==15446== by 0x38002C98: vgMemCheck_malloc >(mc_malloc_wrappers.c:238) >==15446== by 0x3806140E: vgPlain_scheduler (scheduler.c:1394) >==15446== by 0x3808598A: run_a_thread_NORETURN (syswrap-linux.c:94) > >sched status: > running_tid=1 > >Thread 1: status = VgTs_Runnable >==15446== at 0x4C2668A: malloc (vg_replace_malloc.c:236) >==15446== by 0x4058CD: sort(unsigned int**, unsigned int, unsigned >int) (facedetect.cpp:288) >==15446== by 0x407F31: findScrambledArea(cv::Mat&) >(facedetect.cpp:312) >==15446== by 0x40AFED: runOperation(Mode, CryptoKey const&, >DetectorParams&, std::string, std::string, std::string, bool) >(facedetect.cpp:625) >==15446== by 0x40BCC8: main (facedetect.cpp:700) > > > >The code in line 288 of facedetect.cpp looks harmless: > >int* data = (int*) malloc(10); >I tried to run it without valgrind, and for sizes smaller than ~800 my >program seems to run. For anything bigger I get a glibc error. > > > >*** glibc detected *** ./facescramble: malloc(): memory corruption: >0x000000000062b3a0 *** >======= Backtrace: ========= >/lib64/libc.so.6(+0x72f66)[0x7f47a5066f66] >/lib64/libc.so.6(+0x75ffb)[0x7f47a5069ffb] >/lib64/libc.so.6(__libc_malloc+0x70)[0x7f47a506bde0] >./facescramble[0x4058ce] >./facescramble[0x407f32] >./facescramble[0x40afee] >./facescramble[0x40bcc9] >/lib64/libc.so.6(__libc_start_main+0xfd)[0x7f47a5012d2d] >./facescramble[0x4041e9] > > >Does anyone have any ideas why that might occur?! >My glibc version is: sys-libs/glibc-2.12.2 >and I just recompiled it on gentoo to enable the splitdebug feature >which is necessary to run valgrind.
Your program seems to have a bug where it corrupts its memory (e.g. writes past an allocated block or so). This seems to be detected by both Valgrind (through this internal error) and by glibc (reporting a memory corruption). Is Valgrind reporting other errors before ? Then you should fix these. Otherwise, the line above seeems strange: you are allocating 10 bytes assuming this will be used by a pointer to "integer". I would expect that you would allocate a number of bytes multiple of 4 (or 8 maybe). Allocating 10 bytes is strange if you will use this as a pointer to an array of int. Maybe this is the cause of the error somewhere else ? Philippe ____ This message and any files transmitted with it are legally privileged and intended for the sole use of the individual(s) or entity to whom they are addressed. If you are not the intended recipient, please notify the sender by reply and delete the message and any attachments from your system. Any unauthorised use or disclosure of the content of this message is strictly prohibited and may be unlawful. Nothing in this e-mail message amounts to a contractual or legal commitment on the part of EUROCONTROL, unless it is confirmed by appropriately signed hard copy. Any views expressed in this message are those of the sender. ------------------------------------------------------------------------------ EditLive Enterprise is the world's most technically advanced content authoring tool. Experience the power of Track Changes, Inline Image Editing and ensure content is compliant with Accessibility Checking. http://p.sf.net/sfu/ephox-dev2dev _______________________________________________ Valgrind-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/valgrind-users
