[Bug target/109256] New: Error: failed to link 'linked_maps2.bpf.o': Cannot allocate memory (12)

[Bug target/109256] New: Error: failed to link 'linked_maps2.bpf.o': Cannot allocate memory (12)

[james.hilliard1 at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109256

            Bug ID: 109256
           Summary: Error: failed to link 'linked_maps2.bpf.o': Cannot
                    allocate memory (12)
           Product: gcc
           Version: 13.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: target
          Assignee: unassigned at gcc dot gnu.org
          Reporter: james.hilliard1 at gmail dot com
  Target Milestone: ---

I'm seeing this gen object error which does not occur in llvm for a bpf
test(which uses both linked_maps1.c and linked_maps2.c) in bpf-next.

It seems this is triggering a double free in libbpf, not entirely clear if this
is a gcc issue or libbpf issue.

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)

[Bug target/109256] Error: failed to link 'linked_maps2.bpf.o': Cannot allocate memory (12)

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109256

--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Even a bad input should cause an error reported rather than a double free. So
you should at least report it to libbpf too

[Bug target/109256] Error: failed to link 'linked_maps2.bpf.o': Cannot allocate memory (12)

[james.hilliard1 at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109256

--- Comment #2 from James Hilliard <james.hilliard1 at gmail dot com> ---
(In reply to Andrew Pinski from comment #1)
> Even a bad input should cause an error reported rather than a double free.
> So you should at least report it to libbpf too

libbpf bug report:
https://lore.kernel.org/bpf/CADvTj4o7ZWUikKwNTwFq0O_AaX+46t_+Ca9gvWMYdWdRtTGeHQ@mail.gmail.com/

[Bug target/109256] Error: failed to link 'linked_maps2.bpf.o': Cannot allocate memory (12)

[james.hilliard1 at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109256

James Hilliard <james.hilliard1 at gmail dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         Resolution|---                         |FIXED
             Status|UNCONFIRMED                 |RESOLVED

--- Comment #3 from James Hilliard <james.hilliard1 at gmail dot com> ---
Fix has been merged upstream in bpf-next:
https://lore.kernel.org/bpf/20230328004738.381898-3-eddyz87@gmail.com/
https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next.git/commit/?id=d08ab82f59d55b0e5acfeb453081278dfc33f232

[Bug target/109256] Error: failed to link 'linked_maps2.bpf.o': Cannot allocate memory (12)

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=109256

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
         Resolution|FIXED                       |MOVED

--- Comment #4 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Not a GCC bug in the end, so changed to move.