On Wed, Mar 22, 2023 at 9:26 PM James Hilliard <james.hilliard1@xxxxxxxxx> wrote: > > I'm seeing this gen object error with gcc does not occur in llvm for a > bpf test(which uses both linked_maps1.c and linked_maps2.c) in > bpf-next. > > I presume there is a bug in GCC which is triggering a double free bug in libbpf. > Could you somehow share .o files for linked_maps1.c and linked_maps2.c, so I can try to repro locally? > GCC gen object failure: > > ==2125110== Command: > /home/buildroot/bpf-next/tools/testing/selftests/bpf/tools/sbin/bpftool > --debug gen object > /home/buildroot/bpf-next/tools/testing/selftests/bpf/bpf_gcc/linked_maps.linked1.o > /home/buildroot/bpf-next/tools/testing/selftests/bpf/bpf_gcc/linked_maps1.bpf.o > /home/buildroot/bpf-next/tools/testing/selftests/bpf/bpf_gcc/linked_maps2.bpf.o > ==2125110== > libbpf: linker: adding object file > '/home/buildroot/bpf-next/tools/testing/selftests/bpf/bpf_gcc/linked_maps1.bpf.o'... > libbpf: linker: adding object file > '/home/buildroot/bpf-next/tools/testing/selftests/bpf/bpf_gcc/linked_maps2.bpf.o'... > Error: failed to link > '/home/buildroot/bpf-next/tools/testing/selftests/bpf/bpf_gcc/linked_maps2.bpf.o': > Cannot allocate memory (12) > ==2125110== Invalid free() / delete / delete[] / realloc() > ==2125110== at 0x484B0C4: free (vg_replace_malloc.c:884) > ==2125110== by 0x17F8AB: bpf_linker__free (linker.c:204) > ==2125110== by 0x12833C: do_object (gen.c:1608) > ==2125110== by 0x12CDAB: cmd_select (main.c:206) > ==2125110== by 0x129B53: do_gen (gen.c:2332) > ==2125110== by 0x12CDAB: cmd_select (main.c:206) > ==2125110== by 0x12DB9E: main (main.c:539) > ==2125110== Address 0xda4b420 is 0 bytes after a block of size 0 free'd > ==2125110== at 0x484B027: free (vg_replace_malloc.c:883) > ==2125110== by 0x484D6F8: realloc (vg_replace_malloc.c:1451) > ==2125110== by 0x181FA3: extend_sec (linker.c:1117) > ==2125110== by 0x182326: linker_append_sec_data (linker.c:1201) > ==2125110== by 0x1803DC: bpf_linker__add_file (linker.c:453) > ==2125110== by 0x12829E: do_object (gen.c:1593) > ==2125110== by 0x12CDAB: cmd_select (main.c:206) > ==2125110== by 0x129B53: do_gen (gen.c:2332) > ==2125110== by 0x12CDAB: cmd_select (main.c:206) > ==2125110== by 0x12DB9E: main (main.c:539) > ==2125110== Block was alloc'd at > ==2125110== at 0x484876A: malloc (vg_replace_malloc.c:392) > ==2125110== by 0x484D6EB: realloc (vg_replace_malloc.c:1451) > ==2125110== by 0x181FA3: extend_sec (linker.c:1117) > ==2125110== by 0x182326: linker_append_sec_data (linker.c:1201) > ==2125110== by 0x1803DC: bpf_linker__add_file (linker.c:453) > ==2125110== by 0x12829E: do_object (gen.c:1593) > ==2125110== by 0x12CDAB: cmd_select (main.c:206) > ==2125110== by 0x129B53: do_gen (gen.c:2332) > ==2125110== by 0x12CDAB: cmd_select (main.c:206) > ==2125110== by 0x12DB9E: main (main.c:539)
