From ae2e4d4035f511543d12f74b3b7fdb1ba0daab16 Mon Sep 17 00:00:00 2001 From: Xi Ruoyao Date: Tue, 20 Sep 2022 14:09:30 +0800 Subject: LoongArch: Fix R_LARCH_IRELATIVE insertion after elf_link_sort_relocs loongarch_elf_finish_dynamic_symbol is called after elf_link_sort_relocs if -z combreloc. elf_link_sort_relocs redistributes the contents of .rela.* sections those would be merged into .rela.dyn, so the slot for R_LARCH_IRELATIVE may be out of relplt->contents now. To make things worse, the boundary check dyn < dyn + relplt->size / sizeof (*dyn) is obviously wrong ("x + 10 < x"? :), causing the issue undetected during the linking process and the resulted executable suddenly crashes at runtime. The issue was found during an attempt to add static-pie support to the toolchain. Fix it by iterating through the inputs of .rela.dyn to find the slot. --- bfd/elfnn-loongarch.c | 41 +++++++++++++--------- ld/testsuite/ld-loongarch-elf/ld-loongarch-elf.exp | 1 + ld/testsuite/ld-loongarch-elf/local-ifunc-reloc.d | 10 ++++++ ld/testsuite/ld-loongarch-elf/local-ifunc-reloc.s | 28 +++++++++++++++ 4 files changed, 63 insertions(+), 17 deletions(-) create mode 100644 ld/testsuite/ld-loongarch-elf/local-ifunc-reloc.d create mode 100644 ld/testsuite/ld-loongarch-elf/local-ifunc-reloc.s diff --git a/bfd/elfnn-loongarch.c b/bfd/elfnn-loongarch.c index af18a8a..33c85e5 100644 --- a/bfd/elfnn-loongarch.c +++ b/bfd/elfnn-loongarch.c @@ -3514,6 +3514,12 @@ loongarch_elf_finish_dynamic_symbol (bfd *output_bfd, { struct loongarch_elf_link_hash_table *htab = loongarch_elf_hash_table (info); const struct elf_backend_data *bed = get_elf_backend_data (output_bfd); + asection *rela_dyn = bfd_get_section_by_name (output_bfd, ".rela.dyn"); + struct bfd_link_order *lo = NULL; + Elf_Internal_Rela *slot = NULL, *last_slot = NULL; + + if (rela_dyn) + lo = rela_dyn->map_head.link_order; if (h->plt.offset != MINUS_ONE) { @@ -3523,6 +3529,7 @@ loongarch_elf_finish_dynamic_symbol (bfd *output_bfd, uint32_t plt_entry[PLT_ENTRY_INSNS]; bfd_byte *loc; Elf_Internal_Rela rela; + asection *rela_sec = NULL; if (htab->elf.splt) { @@ -3575,31 +3582,31 @@ loongarch_elf_finish_dynamic_symbol (bfd *output_bfd, && (relplt == htab->elf.srelgot || relplt == htab->elf.irelplt)) { - { - rela.r_info = ELFNN_R_INFO (0, R_LARCH_IRELATIVE); - rela.r_addend = (h->root.u.def.value + rela.r_info = ELFNN_R_INFO (0, R_LARCH_IRELATIVE); + rela.r_addend = (h->root.u.def.value + h->root.u.def.section->output_section->vma + h->root.u.def.section->output_offset); - } - /* Find the space after dyn sort. */ + /* Find the space after dyn sort. */ + while (slot == last_slot || slot->r_offset != 0) { - Elf_Internal_Rela *dyn = (Elf_Internal_Rela *)relplt->contents; - bool fill = false; - for (;dyn < dyn + relplt->size / sizeof (*dyn); dyn++) + if (slot != last_slot) { - if (0 == dyn->r_offset) - { - bed->s->swap_reloca_out (output_bfd, &rela, - (bfd_byte *)dyn); - relplt->reloc_count++; - fill = true; - break; - } + slot++; + continue; } - BFD_ASSERT (fill); + + BFD_ASSERT (lo != NULL); + rela_sec = lo->u.indirect.section; + lo = lo->next; + + slot = (Elf_Internal_Rela *)rela_sec->contents; + last_slot = (Elf_Internal_Rela *)(rela_sec->contents + + rela_sec->size); } + bed->s->swap_reloca_out (output_bfd, &rela, (bfd_byte *)slot); + rela_sec->reloc_count++; } else { diff --git a/ld/testsuite/ld-loongarch-elf/ld-loongarch-elf.exp b/ld/testsuite/ld-loongarch-elf/ld-loongarch-elf.exp index dfa8ee1..726ee82 100644 --- a/ld/testsuite/ld-loongarch-elf/ld-loongarch-elf.exp +++ b/ld/testsuite/ld-loongarch-elf/ld-loongarch-elf.exp @@ -31,6 +31,7 @@ if [istarget "loongarch64-*-*"] { run_dump_test "macro_op" run_dump_test "syscall" run_dump_test "disas-jirl" + run_dump_test "local-ifunc-reloc" } if [istarget "loongarch32-*-*"] { diff --git a/ld/testsuite/ld-loongarch-elf/local-ifunc-reloc.d b/ld/testsuite/ld-loongarch-elf/local-ifunc-reloc.d new file mode 100644 index 0000000..29f2d3f --- /dev/null +++ b/ld/testsuite/ld-loongarch-elf/local-ifunc-reloc.d @@ -0,0 +1,10 @@ +#as: +#ld: -shared -z combreloc +#objdump: -R + +.*: +file format .* + +DYNAMIC RELOCATION RECORDS +OFFSET +TYPE +VALUE +[[:xdigit:]]+ R_LARCH_IRELATIVE +\*ABS\*\+0x[[:xdigit:]]+ +[[:xdigit:]]+ R_LARCH_64 +test diff --git a/ld/testsuite/ld-loongarch-elf/local-ifunc-reloc.s b/ld/testsuite/ld-loongarch-elf/local-ifunc-reloc.s new file mode 100644 index 0000000..77c4874 --- /dev/null +++ b/ld/testsuite/ld-loongarch-elf/local-ifunc-reloc.s @@ -0,0 +1,28 @@ +.text +.align 2 + +.local ifunc +.type ifunc, @gnu_indirect_function +.set ifunc, resolver + +resolver: + la.local $a0, impl + jr $ra + +impl: + li.w $a0, 42 + jr $ra + +.global test +.type test, @function +test: + move $s0, $ra + bl ifunc + xori $a0, $a0, 42 + jr $s0 + +.data +.global ptr +.type ptr, @object +ptr: + .dword test -- cgit v1.1