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Hi! IMHO R_386_TLS_DTPMOD32 should not use addend in REL version. It is a counterpart of R_386_GLOB_DAT which doesn't use it either. I believe the reason for R_386_GLOB_DAT is that if you reference x, x + 8 and x + 16 in one library, you don't end up with 3 dynamic relocs against x but just one. ATM binutils will never create R_386_TLS_DTPMOD32 with addend != 0 (unlike R_386_TLS_TPOFF32). Not using the addend has a serious advantage for prelink - it can prelink all DTPOFF32 relocs without the need for costly REL->RELA conversion. Another thing is that sym != NULL implies sym_map != NULL (otherwise e.g. Elf32_Addr value = sym == NULL ? 0 : sym_map->l_addr + sym->st_value; would crash first). Plus we need the TLS RELA support too... 2002-09-12 Jakub Jelinek <jakub@redhat.com> * sysdeps/i386/dl-machine.h (elf_machine_rel) [R_386_TLS_DTPMOD32]: Don't use addend. [R_386_TLS_TPOFF32]: Remove redundant sym_map != NULL check. (elf_machine_rela): Add support for TLS relocs. --- libc/sysdeps/i386/dl-machine.h.jj 2002-08-31 09:40:43.000000000 +0200 +++ libc/sysdeps/i386/dl-machine.h 2002-09-12 18:19:22.000000000 +0200 @@ -410,8 +410,6 @@ elf_machine_rel (struct link_map *map, c *reloc_addr = value; break; - /* XXX Remove TLS relocations which are not needed. */ - #ifdef USE_TLS case R_386_TLS_DTPMOD32: # ifdef RTLD_BOOTSTRAP @@ -432,7 +430,7 @@ elf_machine_rel (struct link_map *map, c /* During relocation all TLS symbols are defined and used. Therefore the offset is already correct. */ if (sym != NULL) - *reloc_addr += sym->st_value; + *reloc_addr = sym->st_value; # endif break; case R_386_TLS_TPOFF32: @@ -444,7 +442,7 @@ elf_machine_rel (struct link_map *map, c It is a positive value which will be subtracted from the thread pointer. To get the variable position in the TLS block we subtract the offset from that of the TLS block. */ - if (sym_map != NULL && sym != NULL) + if (sym != NULL) *reloc_addr += sym_map->l_tls_offset - sym->st_value; # endif break; @@ -516,7 +514,44 @@ elf_machine_rela (struct link_map *map, case R_386_PC32: *reloc_addr = (value + reloc->r_addend - (Elf32_Addr) reloc_addr); break; - /* XXX Do we have to handle the TLS relocation here? */ + +#ifdef USE_TLS + case R_386_TLS_DTPMOD32: +# ifdef RTLD_BOOTSTRAP + /* During startup the dynamic linker is always the module + with index 1. + XXX If this relocation is necessary move before RESOLVE + call. */ + *reloc_addr = 1; +# else + /* Get the information from the link map returned by the + resolv function. */ + if (sym_map != NULL) + *reloc_addr = sym_map->l_tls_modid; +# endif + break; + case R_386_TLS_DTPOFF32: +# ifndef RTLD_BOOTSTRAP + /* During relocation all TLS symbols are defined and used. + Therefore the offset is already correct. */ + *reloc_addr = (sym == NULL ? 0 : sym->st_value) + reloc->r_addend; +# endif + break; + case R_386_TLS_TPOFF32: + /* The offset is positive, backward from the thread pointer. */ +# ifdef RTLD_BOOTSTRAP + *reloc_addr = map->l_tls_offset - sym->st_value + reloc->r_addend; +# else + /* We know the offset of object the symbol is contained in. + It is a positive value which will be subtracted from the + thread pointer. To get the variable position in the TLS + block we subtract the offset from that of the TLS block. */ + *reloc_addr + = (sym == NULL ? 0 : sym_map->l_tls_offset - sym->st_value) + + reloc->r_addend; +# endif + break; +#endif /* use TLS */ default: /* We add these checks in the version to relocate ld.so only if we are still debugging. */ Jakub
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