https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80038
Bug ID: 80038 Summary: Random segfault using local vectors in Cilk function Product: gcc Version: 6.3.1 Status: UNCONFIRMED Severity: normal Priority: P3 Component: c++ Assignee: unassigned at gcc dot gnu.org Reporter: florent.hivert at lri dot fr Target Milestone: --- The following (reduced) code works if using only one core but segfault randomly when using more core. The more core your have, the more chance you have to get a segfault. Sometime it also fail with a double free error. I compiled it using g++-6 -std=c++11 -fcilkplus -g -Wall -lcilkrts red2.cpp -o red2 #include <vector> #include <cilk/cilk.h> void walk(std::vector<int> v, unsigned size) { if (v.size() < size) for (int i=0; i<8; i++) { std::vector<int> vnew(v); vnew.push_back(i); cilk_spawn walk(vnew, size); } } int main(int argc, char **argv) { std::vector<int> v{}; walk(v, 5); } FWIW: $ g++-6 -v Using built-in specs. COLLECT_GCC=g++-6 COLLECT_LTO_WRAPPER=/usr/lib64/gcc/x86_64-suse-linux/6/lto-wrapper Target: x86_64-suse-linux Configured with: ../configure --prefix=/usr --infodir=/usr/share/info --mandir=/usr/share/man --libdir=/usr/lib64 --libexecdir=/usr/lib64 --enable-languages=c,c++,objc,fortran,obj-c++,java,ada,go --enable-offload-targets=hsa --enable-checking=release --with-gxx-include-dir=/usr/include/c++/6 --enable-ssp --disable-libssp --disable-libvtv --disable-libcc1 --disable-plugin --with-bugurl=http://bugs.opensuse.org/ --with-pkgversion='SUSE Linux' --disable-libgcj --with-slibdir=/lib64 --with-system-zlib --enable-__cxa_atexit --enable-libstdcxx-allocator=new --disable-libstdcxx-pch --with-default-libstdcxx-abi=gcc4-compatible --enable-version-specific-runtime-libs --enable-linker-build-id --enable-linux-futex --enable-gnu-indirect-function --program-suffix=-6 --without-system-libunwind --enable-multilib --with-arch-32=x86-64 --with-tune=generic --build=x86_64-suse-linux --host=x86_64-suse-linux Thread model: posix gcc version 6.3.1 20170202 [gcc-6-branch revision 245119] (SUSE Linux)