Given the parameters to jerasure_matrix_dotprod the code path should be: https://github.com/ceph/jerasure/blob/v2-ceph/src/galois.c#L338 (because nbytes == 2048) https://github.com/ceph/jerasure/blob/v2-ceph/src/galois.c#L332 https://github.com/ceph/gf-complete/blob/v1-ceph/src/gf_w32.c#L569 (because INTEL_SSE4_PCLMUL has been used at compile time and the CPUID detected at runtime has the required features as selected in https://github.com/ceph/ceph/blob/master/src/erasure-code/jerasure/ErasureCodePluginSelectJerasure.cc#L49 ) what should happen after that ? h->prim_poly will select something but what exactly... Could it be that the lack of stack means https://github.com/ceph/jerasure/blob/v2-ceph/src/galois.c#L332 references a NULL or invalid gfp_array[32] ? Or could it be that src/dest pointers are pointing to invalid memory ?
Bugs that can't be reproduced are the best ;-) On 02/04/2014 19:35, Loic Dachary wrote:> Hi Kevin, > > In the context of http://tracker.ceph.com/issues/7914 we're trying to figure > out why jerasure dumps core. We don't know how to reproduce it yet (ran > dozens of identical tests suites with no such crash in the past few days, > which is to be expected for rare bugs because the test suite introduces > random errors / failures on purpose). > > The full stack trace is at http://tracker.ceph.com/issues/7914#note-24 but > the relevant part is here: > > #0 0x00007f4756779b7b in raise (sig=<optimized out>) at > ../nptl/sysdeps/unix/sysv/linux/pt-raise.c:42 > #1 0x0000000000981b4e in reraise_fatal (signum=11) at > global/signal_handler.cc:59 > #2 handle_fatal_signal (signum=11) at global/signal_handler.cc:105 > #3 <signal handler called> > #4 0x0000000000000000 in ?? () > #5 0x00007f47385ae6b1 in jerasure_matrix_dotprod (k=2, w=8, > matrix_row=0x31513a8, src_ids=0x0, dest_id=<optimized out>, > data_ptrs=0x7f4741ec7a00, coding_ptrs=0x7f4741ec7a10, > size=2048) at erasure-code/jerasure/jerasure/src/jerasure.c:607 > #6 0x00007f47385ae7d6 in jerasure_matrix_encode (k=2, m=1, w=8, > matrix=<optimized out>, data_ptrs=0x7f4741ec7a00, coding_ptrs=0x7f4741ec7a10, > size=2048) > at erasure-code/jerasure/jerasure/src/jerasure.c:310 > ... > > Note that this jerasure/gf-complete combination has been compiled with > SSE4.1, SSE4.2, PCLMUL, SSSE3, SSE3, SSE2, SSE flags activated. These are > jerasure v2 and gf-complete v1, only slightly modified as found in > https://github.com/ceph/jerasure/tree/v2-ceph and > https://github.com/ceph/gf-complete/tree/v1-ceph (all commits there have a > pending pull request under https://bitbucket.org/jimplank/gf-complete > https://bitbucket.org/jimplank/jerasure, nothing you've not seen before). > > #5 is https://github.com/ceph/jerasure/blob/v2-ceph/src/jerasure.c#L607 > > and then it dives into gf-complete and most probably destroyed part of the > stack when corrupting memory. I'll be chasing this tomorrow. If you have a > brilliant idea on why that happens, I'll take it ;-) > > Cheers > -- Loïc Dachary, Artisan Logiciel Libre
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