Matrix-free: out of bounds vector access

[tamiko]

My desktop system has a "hardened" libstdc++ library version installed that has assertions for bounds checks compiled in. When running the testsuite a number of matrix-free tests are failing for me with an assert. For example:

/usr/lib/gcc/x86_64-pc-linux-gnu/13/include/g++-v13/bits/stl_vector.h:1125: std::vector<_Tp, _Alloc>::reference std::vector<_Tp, _Alloc>::operator[](size_type) [with _Tp = unsigned int; _Alloc = std::allocator<unsigned int>; reference = unsigned int&; size_type = long unsigned int]: Assertion '__n < this->size()' failed.

Here is an exemplary stack trace how the assertion is triggered:

#0  __pthread_kill_implementation (threadid=<optimized out>, signo=signo@entry=6, no_tid=no_tid@entry=0) at pthread_kill.c:44
#1  0x00007fffb94afd63 in __pthread_kill_internal (signo=6, threadid=<optimized out>) at pthread_kill.c:78
#2  0x00007fffb9460f26 in __GI_raise (sig=sig@entry=6) at ../sysdeps/posix/raise.c:26
#3  0x00007fffb944a87c in __GI_abort () at abort.c:79
#4  0x00007fffaeb0f78f in std::__glibcxx_assert_fail(char const*, int, char const*, char const*)
    (file=<optimized out>, line=<optimized out>, function=<optimized out>, condition=<optimized out>)
    at /var/tmp/portage/sys-devel/gcc-13.1.1_p20230527/work/gcc-13-20230527/libstdc++-v3/src/c++11/debug.cc:61
#5  0x000055555568bcb7 in std::vector<unsigned int, std::allocator<unsigned int> >::operator[](unsigned long) (this=0x5555559ae0a8, __n=128)
    at /usr/lib/gcc/x86_64-pc-linux-gnu/13/include/g++-v13/bits/stl_vector.h:1125
#6  0x00007fffee0d6fb7 in dealii::internal::MatrixFreeFunctions::DoFInfo::compute_cell_index_compression(std::vector<unsigned char, std::allocator<unsigned char> > const&)
    (this=0x5555559ae040, irregular_cells=std::vector of length 32, capacity 32 = {...}) at /home/tamiko/workspace/dealii/source/matrix_free/dof_info.cc:640
#7  0x00007fffee0d6066 in dealii::internal::MatrixFreeFunctions::DoFInfo::reorder_cells(dealii::internal::MatrixFreeFunctions::TaskInfo const&, std::vector<unsigned int, std::allocator<unsigned int> > const&, std::vector<unsigned int, std::allocator<unsigned int> > const&, std::vector<unsigned char, std::allocator<unsigned char> > const&)
    (this=0x5555559ae040, task_info=..., renumbering=std::vector of length 64, capacity 64 = {...}, constraint_pool_row_index=std::vector of length 1, capacity 1 = {...}, irregular_cells=std::vector of length 32, capacity 32 = {...}) at /home/tamiko/workspace/dealii/source/matrix_free/dof_info.cc:524
#8  0x00007ffff1cbe85f in dealii::internal::compute_dof_info<2, double>(std::vector<dealii::AffineConstraints<double> const*, std::allocator<dealii::AffineConstraints<double> const*> > const&, std::vector<dealii::IndexSet, std::allocator<dealii::IndexSet> > const&, std::vector<dealii::SmartPointer<dealii::DoFHandler<2, 2> const, void>, std::allocator<dealii::SmartPointer<dealii::DoFHandler<2, 2> const, void> > > const&, dealii::Table<2, dealii::internal::MatrixFreeFunctions::ShapeInfo<double> > const&, unsigned int, unsigned int, bool, std::vector<unsigned int, std::allocator<unsigned int> > const&, bool, bool, bool, bool, dealii::internal::MatrixFreeFunctions::TaskInfo&, std::vector<std::pair<unsigned int, unsigned int>, std::allocator<std::pair<unsigned int, unsigned int> > >&, std::vector<dealii::internal::MatrixFreeFunctions::DoFInfo, std::allocator<dealii::internal::MatrixFreeFunctions::DoFInfo> >&, dealii::internal::MatrixFreeFunctions::FaceSetup<2>&, dealii::internal::MatrixFreeFunctions::ConstraintValues<double>&, bool)
    (constraint=std::vector of length 1, capacity 1 = {...}, locally_owned_dofs=std::vector of length 1, capacity 1 = {...}, dof_handler=std::vector of length 1, capacity 1 = {...}, shape_infos=..., cell_level_index_end_local=64, mg_level=4294967295, hold_all_faces_to_owned_cells=false, cell_vectorization_category=std::vector of length 0, capacity 0, cell_vectorization_categories_strict=false, do_face_integrals=true, build_inner_faces=true, overlap_communication_computation=true, task_info=..., cell_level_index=std::vector of length 64, capacity 64 = {...}, dof_info=std::vector of length 1, capacity 1 = {...}, face_setup=..., constraint_values=..., use_vector_data_exchanger_full=false) at /home/tamiko/workspace/dealii/include/deal.II/matrix_free/matrix_free.templates.h:1843
#9  0x00007ffff1c7868f in dealii::MatrixFree<2, double, dealii::VectorizedArray<double, 2ul> >::initialize_indices<double>(std::vector<dealii::AffineConstraints<double> const*, std::allocator<dealii::AffineConstraints<double> const*> > const&, std::vector<dealii::IndexSet, std::allocator<dealii::IndexSet> > const&, dealii::MatrixFree<2, double, dealii::VectorizedArray<double, 2ul> >::AdditionalData const&)
    (this=0x7fffffffd720, constraint=std::vector of length 1, capacity 1 = {...}, locally_owned_dofs=std::vector of length 1, capacity 1 = {...}, additional_data=...)
    at /home/tamiko/workspace/dealii/include/deal.II/matrix_free/matrix_free.templates.h:1894
#10 0x00007ffff1c02f47 in dealii::MatrixFree<2, double, dealii::VectorizedArray<double, 2ul> >::internal_reinit<double, 2>(std::shared_ptr<dealii::hp::MappingCollection<2, 2> > const&, std::vector<dealii::DoFHandler<2, 2> const*, std::allocator<dealii::DoFHandler<2, 2> const*> > const&, std::vector<dealii::AffineConstraints<double> const*, std::allocator<dealii::AffineConstraints<double> const*> > const&, std::vector<dealii::IndexSet, std::allocator<dealii::IndexSet> > const&, std::vector<dealii::hp::QCollection<2>, std::allocator<dealii::hp::QCollection<2> > > const&, dealii::MatrixFree<2, double, dealii::VectorizedArray<double, 2ul> >::AdditionalData const&)
    (this=0x7fffffffd720, mapping=std::shared_ptr<dealii::hp::MappingCollection<2, 2>> (use count 1, weak count 0) = {...}, dof_handler=std::vector of length 1, capacity 1 = {...}, constraints=std::vector of length 1, capacity 1 = {...}, locally_owned_dofs=std::vector of length 1, capacity 1 = {...}, quad=std::vector of length 1, capacity 1 = {...}, additional_data=...) at /home/tamiko/workspace/dealii/include/deal.II/matrix_free/matrix_free.templates.h:503
#11 0x00005555556970b3 in dealii::MatrixFree<2, double, dealii::VectorizedArray<double, 2ul> >::reinit<dealii::QGauss<2>, double, dealii::MappingQ1<2, 2> >(dealii::MappingQ1<2, 2> const&, dealii::DoFHandler<2, 2> const&, dealii::AffineConstraints<double> const&, dealii::QGauss<2> const&, dealii::MatrixFree<2, double, dealii::VectorizedArray<dou--Type <RET> for more, q to quit, c to continue without paging--
ble, 2ul> >::AdditionalData const&) (this=0x7fffffffd720, mapping=..., dof_handler=..., constraints_in=..., quad=..., additional_data=...)
    at /home/tamiko/workspace/dealii/include/deal.II/matrix_free/matrix_free.h:3167
#12 0x00005555556926fc in test<2>(unsigned int) (n_refinements=2) at /home/tamiko/workspace/dealii/tests/matrix_free/element_birth_and_death_01.cc:99
#13 0x000055555567ee12 in main(int, char**) (argc=1, argv=0x7fffffffdf38) at /home/tamiko/workspace/dealii/tests/matrix_free/element_birth_and_death_01.cc:208

This was when executing the matrix_free/element_birth_and_death_01 test.

In reference to #15383

[tamiko]

@kronbichler @peterrum ping

[kronbichler]

I will look into it in around 6 hours.

[kronbichler]

I see

==55542== Invalid read of size 4
==55542==    at 0x12500C6C: dealii::internal::MatrixFreeFunctions::DoFInfo::compute_cell_index_compression(std::vector<unsigned char, std::allocator<unsigned char> > const&) (deal.II/source/matrix_free/dof_info.cc:637)
==55542==    by 0x12500028: dealii::internal::MatrixFreeFunctions::DoFInfo::reorder_cells(dealii::internal::MatrixFreeFunctions::TaskInfo const&, std::vector<unsigned int, std::allocator<unsigned int> > const&, std::vector<unsigned int, std::allocator<unsigned int> > const&, std::vector<unsigned char, std::allocator<unsigned char> > const&) (deal.II/source/matrix_free/dof_info.cc:524)
...
==55542==  Address 0x2f4dd0a0 is 0 bytes after a block of size 512 alloc'd
...
==55542==    by 0x124FF3D0: reserve (vector.tcc:79)
==55542==    by 0x124FF3D0: dealii::internal::MatrixFreeFunctions::DoFInfo::reorder_cells(dealii::internal::MatrixFreeFunctions::TaskInfo const&, std::vector<unsigned int, std::allocator<unsigned int> > const&, std::vector<unsigned int, std::allocator<unsigned int> > const&, std::vector<unsigned char, std::allocator<unsigned char> > const&) (deal.II/source/matrix_free/dof_info.cc:350)
...

[tamiko]

#15430 did indeed fix about 90% of failing matrix free tests. There is some residual fallout due to yet another bounds violation in DoFAccessorImplementation::Implementation::process_object, opening a bug report.