On Wed, Mar 17, 2021 at 03:13:43PM +0100, Peter Zijlstra wrote: > On Wed, Mar 17, 2021 at 02:52:23PM +0100, Miroslav Benes wrote: > > > > + if (!elf_symbol_add(elf, sym, SHN_XINDEX)) { > > > + WARN("elf_symbol_add"); > > > + return NULL; > > > + } > > > > SHN_XINDEX means that the extended section index is used. Above you seem > > to use it in the opposite sense too (assigning to shndx when shndx_data is > > NULL). While it makes the code easier to handle, it is a bit confusing > > (and maybe I am just confused now). Could you add a comment about that, > > please? elf_symbol_add() seems like a good place. > > Yes, that was a horrible thing to do :/ And you understood it right. > > Looking at it again, I'm not sure it is actually correct tho; shouldn't > elf_create_undef_symbol() also look at gelf_getsymshndx() of symtab ? > > What toolchain generates these extended sections and how? That is, how > do I test this crud..
SHN_XINDEX is basically a special-case extension to original ELF for supporting more than 64k sections. -- Josh