From b67a17aa7c0c478a2f2c2f045854e9745abfe114 Mon Sep 17 00:00:00 2001 From: Lulu Cai Date: Thu, 21 Mar 2024 16:33:21 +0800 Subject: LoongArch: Fix the issue of excessive relocation generated by GD and IE Currently, whether GD and IE generate dynamic relocation is determined by SYMBOL_REFERENCES_LOCAL and bfd_link_executable. This results in dynamic relocations still being generated in some situations where dynamic relocations are not necessary (such as the undefined weak symbol in static links). We use RLARCH_TLS_GD_IE_NEED_DYN_RELOC macros to determine whether GD/IE needs dynamic relocation. If GD/IE requires dynamic relocation, set need_reloc to true and indx to be a dynamic index. At the same time, some test cases were modified to use regular expression matching instead of complete disassembly matching. --- bfd/elfnn-loongarch.c | 179 ++++++++++++++++++++++++++------------------------ 1 file changed, 93 insertions(+), 86 deletions(-) (limited to 'bfd') diff --git a/bfd/elfnn-loongarch.c b/bfd/elfnn-loongarch.c index 1679aa5..952c42d 100644 --- a/bfd/elfnn-loongarch.c +++ b/bfd/elfnn-loongarch.c @@ -159,6 +159,27 @@ struct loongarch_elf_link_hash_table || (R_TYPE) == R_LARCH_TLS_LE64_LO20 \ || (R_TYPE) == R_LARCH_TLS_LE64_HI12) +/* If TLS GD/IE need dynamic relocations, INDX will be the dynamic indx, + and set NEED_RELOC to true used in allocate_dynrelocs and + loongarch_elf_relocate_section for TLS GD/IE. */ +#define LARCH_TLS_GD_IE_NEED_DYN_RELOC(INFO, DYN, H, INDX, NEED_RELOC) \ + do \ + { \ + if ((H) != NULL \ + && (H)->dynindx != -1 \ + && WILL_CALL_FINISH_DYNAMIC_SYMBOL ((DYN), \ + bfd_link_pic (INFO), (H))) \ + (INDX) = (H)->dynindx; \ + if (((H) == NULL \ + || ELF_ST_VISIBILITY ((H)->other) == STV_DEFAULT \ + || (H)->root.type != bfd_link_hash_undefweak) \ + && (!bfd_link_executable (INFO) \ + || (INDX) != 0)) \ + (NEED_RELOC) = true; \ + } \ + while (0) + + /* Generate a PLT header. */ static bool @@ -1276,40 +1297,24 @@ allocate_dynrelocs (struct elf_link_hash_entry *h, void *inf) h->got.offset = s->size; if (tls_type & (GOT_TLS_GD | GOT_TLS_IE | GOT_TLS_GDESC)) { + int indx = 0; + bool need_reloc = false; + LARCH_TLS_GD_IE_NEED_DYN_RELOC (info, dyn, h, indx, + need_reloc); /* TLS_GD needs two dynamic relocs and two GOT slots. */ if (tls_type & GOT_TLS_GD) { s->size += 2 * GOT_ENTRY_SIZE; - if (bfd_link_executable (info)) - { - /* Link exe and not defined local. */ - if (!SYMBOL_REFERENCES_LOCAL (info, h)) - htab->elf.srelgot->size += 2 * sizeof (ElfNN_External_Rela); - } - else - { - if (SYMBOL_REFERENCES_LOCAL (info, h)) - htab->elf.srelgot->size += sizeof (ElfNN_External_Rela); - else - htab->elf.srelgot->size += 2 * sizeof (ElfNN_External_Rela); - } + if (need_reloc) + htab->elf.srelgot->size += 2 * sizeof (ElfNN_External_Rela); } /* TLS_IE needs one dynamic reloc and one GOT slot. */ if (tls_type & GOT_TLS_IE) { s->size += GOT_ENTRY_SIZE; - - if (bfd_link_executable (info)) - { - /* Link exe and not defined local. */ - if (!SYMBOL_REFERENCES_LOCAL (info, h)) - htab->elf.srelgot->size += sizeof (ElfNN_External_Rela); - } - else - { - htab->elf.srelgot->size += sizeof (ElfNN_External_Rela); - } + if (need_reloc) + htab->elf.srelgot->size += 2 * sizeof (ElfNN_External_Rela); } /* TLS_DESC needs one dynamic reloc and two GOT slot. */ @@ -2550,13 +2555,18 @@ loongarch_reloc_is_fatal (struct bfd_link_info *info, }) +/* Compute the tp/dtp offset of a tls symbol. + It is dtp offset in dynamic tls model (gd/ld) and tp + offset in static tls model (ie/le). Both offsets are + calculated the same way on LoongArch, so the same + function is used. */ static bfd_vma -tls_dtpoff_base (struct bfd_link_info *info) +tlsoff (struct bfd_link_info *info, bfd_vma addr) { /* If tls_sec is NULL, we should have signalled an error already. */ if (elf_hash_table (info)->tls_sec == NULL) return 0; - return elf_hash_table (info)->tls_sec->vma; + return addr - elf_hash_table (info)->tls_sec->vma; } @@ -2890,7 +2900,7 @@ loongarch_elf_relocate_section (bfd *output_bfd, struct bfd_link_info *info, is_undefweak, name, "TLS section not be created"); } else - relocation -= elf_hash_table (info)->tls_sec->vma; + relocation = tlsoff (info, relocation); } else { @@ -3416,7 +3426,7 @@ loongarch_elf_relocate_section (bfd *output_bfd, struct bfd_link_info *info, case R_LARCH_TLS_LE_HI20_R: relocation += rel->r_addend; - relocation -= elf_hash_table (info)->tls_sec->vma; + relocation = tlsoff (info, relocation); RELOCATE_TLS_TP32_HI20 (relocation); break; @@ -3599,7 +3609,7 @@ loongarch_elf_relocate_section (bfd *output_bfd, struct bfd_link_info *info, BFD_ASSERT (resolved_local && elf_hash_table (info)->tls_sec); relocation += rel->r_addend; - relocation -= elf_hash_table (info)->tls_sec->vma; + relocation = tlsoff (info, relocation); break; /* TLS IE LD/GD process separately is troublesome. @@ -3654,71 +3664,72 @@ loongarch_elf_relocate_section (bfd *output_bfd, struct bfd_link_info *info, /* If a tls variable is accessed in multiple ways, GD uses the first two slots of GOT, desc follows with two slots, and IE uses one slot at the end. */ - desc_off = 0; - if (GOT_TLS_GD_BOTH_P (tls_type)) - desc_off = 2 * GOT_ENTRY_SIZE; - - ie_off = 0; - if (GOT_TLS_GD_BOTH_P (tls_type) && (tls_type & GOT_TLS_IE)) - ie_off = 4 * GOT_ENTRY_SIZE; - else if (GOT_TLS_GD_ANY_P (tls_type) && (tls_type & GOT_TLS_IE)) - ie_off = 2 * GOT_ENTRY_SIZE; + off = 0; + if (tls_type & GOT_TLS_GD) + off += 2 * GOT_ENTRY_SIZE; + desc_off = off; + if (tls_type & GOT_TLS_GDESC) + off += 2 * GOT_ENTRY_SIZE; + ie_off = off; if ((got_off & 1) == 0) { Elf_Internal_Rela rela; asection *relgot = htab->elf.srelgot; - bfd_vma tls_block_off = 0; - if (SYMBOL_REFERENCES_LOCAL (info, h)) - { - BFD_ASSERT (elf_hash_table (info)->tls_sec); - tls_block_off = relocation - - elf_hash_table (info)->tls_sec->vma; - } + int indx = 0; + bool need_reloc = false; + LARCH_TLS_GD_IE_NEED_DYN_RELOC (info, is_dyn, h, indx, + need_reloc); if (tls_type & GOT_TLS_GD) { - rela.r_offset = sec_addr (got) + got_off; - rela.r_addend = 0; - if (SYMBOL_REFERENCES_LOCAL (info, h)) + if (need_reloc) { - /* Local sym, used in exec, set module id 1. */ - if (bfd_link_executable (info)) - bfd_put_NN (output_bfd, 1, got->contents + got_off); + /* Dynamic resolved Module ID. */ + rela.r_offset = sec_addr (got) + got_off; + rela.r_addend = 0; + rela.r_info = ELFNN_R_INFO (indx,R_LARCH_TLS_DTPMODNN); + bfd_put_NN (output_bfd, 0, got->contents + got_off); + loongarch_elf_append_rela (output_bfd, relgot, &rela); + + if (indx == 0) + { + /* Local symbol, tp offset has been known. */ + BFD_ASSERT (! unresolved_reloc); + bfd_put_NN (output_bfd, + tlsoff (info, relocation), + (got->contents + got_off + GOT_ENTRY_SIZE)); + } else { - rela.r_info = ELFNN_R_INFO (0, R_LARCH_TLS_DTPMODNN); + /* Dynamic resolved block offset. */ + bfd_put_NN (output_bfd, 0, + got->contents + got_off + GOT_ENTRY_SIZE); + rela.r_info = ELFNN_R_INFO (indx, + R_LARCH_TLS_DTPRELNN); + rela.r_offset += GOT_ENTRY_SIZE; loongarch_elf_append_rela (output_bfd, relgot, &rela); } - - bfd_put_NN (output_bfd, tls_block_off, - got->contents + got_off + GOT_ENTRY_SIZE); } - /* Dynamic resolved. */ else { - /* Dynamic relocate module id. */ - rela.r_info = ELFNN_R_INFO (h->dynindx, - R_LARCH_TLS_DTPMODNN); - loongarch_elf_append_rela (output_bfd, relgot, &rela); - - /* Dynamic relocate offset of block. */ - rela.r_offset += GOT_ENTRY_SIZE; - rela.r_info = ELFNN_R_INFO (h->dynindx, - R_LARCH_TLS_DTPRELNN); - loongarch_elf_append_rela (output_bfd, relgot, &rela); + /* In a static link or an executable link with the symbol + binding locally. Mark it as belonging to module 1. */ + bfd_put_NN (output_bfd, 1, got->contents + got_off); + bfd_put_NN (output_bfd, tlsoff (info, relocation), + got->contents + got_off + GOT_ENTRY_SIZE); } } if (tls_type & GOT_TLS_GDESC) { /* Unless it is a static link, DESC always emits a dynamic relocation. */ - int indx = h && h->dynindx != -1 ? h->dynindx : 0; + indx = h && h->dynindx != -1 ? h->dynindx : 0; rela.r_offset = sec_addr (got) + got_off + desc_off; rela.r_addend = 0; if (indx == 0) - rela.r_addend = relocation - tls_dtpoff_base (info); + rela.r_addend = tlsoff (info, relocation); rela.r_info = ELFNN_R_INFO (indx, R_LARCH_TLS_DESCNN); loongarch_elf_append_rela (output_bfd, relgot, &rela); @@ -3727,28 +3738,24 @@ loongarch_elf_relocate_section (bfd *output_bfd, struct bfd_link_info *info, } if (tls_type & GOT_TLS_IE) { - rela.r_offset = sec_addr (got) + got_off + ie_off; - if (SYMBOL_REFERENCES_LOCAL (info, h)) + if (need_reloc) { - /* Local sym, used in exec, set module id 1. */ - if (!bfd_link_executable (info)) - { - rela.r_info = ELFNN_R_INFO (0, R_LARCH_TLS_TPRELNN); - rela.r_addend = tls_block_off; - loongarch_elf_append_rela (output_bfd, relgot, &rela); - } + bfd_put_NN (output_bfd, 0, + got->contents + got_off + ie_off); + rela.r_offset = sec_addr (got) + got_off + ie_off; + rela.r_addend = 0; - bfd_put_NN (output_bfd, tls_block_off, - got->contents + got_off + ie_off); + if (indx == 0) + rela.r_addend = tlsoff (info, relocation); + rela.r_info = ELFNN_R_INFO (indx, R_LARCH_TLS_TPRELNN); + loongarch_elf_append_rela (output_bfd, relgot, &rela); } - /* Dynamic resolved. */ else { - /* Dynamic relocate offset of block. */ - rela.r_info = ELFNN_R_INFO (h->dynindx, - R_LARCH_TLS_TPRELNN); - rela.r_addend = 0; - loongarch_elf_append_rela (output_bfd, relgot, &rela); + /* In a static link or an executable link with the symbol + bindinglocally, compute offset directly. */ + bfd_put_NN (output_bfd, tlsoff (info, relocation), + got->contents + got_off + ie_off); } } } @@ -3787,7 +3794,7 @@ loongarch_elf_relocate_section (bfd *output_bfd, struct bfd_link_info *info, tls_type = _bfd_loongarch_elf_tls_type (input_bfd, h, r_symndx); /* Use both TLS_GD and TLS_DESC. */ - if ((tls_type & GOT_TLS_GD) && (tls_type & GOT_TLS_GDESC)) + if (GOT_TLS_GD_BOTH_P (tls_type)) relocation += 2 * GOT_ENTRY_SIZE; if (r_type == R_LARCH_TLS_DESC64_PC_LO20) -- cgit v1.1