On Thu, Aug 20, 2020 at 10:54 AM Yonghong Song <yhs@xxxxxx> wrote: > > > > On 8/20/20 10:36 AM, Mark Wielaard wrote: > > Hi > > > > On Thu, 2020-08-20 at 08:51 -0700, Yonghong Song wrote: > >>>> Do you think we could skip these .debug_* sections somehow in elf > >>>> parsing in resolve_btfids? resolve_btfids does not need to read > >>>> these sections. This way, no need to change their alignment > >>>> either. > >>> > >>> The issue is that elfutils libelf will not allow writing out the > >>> section when it notices the sh_addralign field is setup wrongly. > >> > >> Maybe resolve_btfids can temporarily change sh_addralign to 4/8 > >> before elf manipulation (elf_write) to make libelf happy. > >> After all elf_write is done, change back to whatever the > >> original value (1). Does this work? > > > > Unfortunately no, because there is no elf_write, elf_update is how you > > write out the ELF image to disc. > > > > Since the code is using ELF_F_LAYOUT this will not change the actual > > layout of the ELF image if that is what you are worried about. > > > > And the workaround to set sh_addralign correctly before calling > > elf_update is precisely what the fix in elfutils libelf will do itself > > in the next release. Also binutils ld has been fixed to setup > > sh_addralign to 4/8 as appropriate now (in git). > > Sounds good then. > Thanks for fixing the issue in upstream, both libelf and binutils! In the meantime I've applied Jiri's workaround to bpf tree. Thanks!
