From 48db3297342d798e58a00771a67b9b4c93412920 Mon Sep 17 00:00:00 2001 From: Alan Modra Date: Mon, 14 Oct 2019 13:50:48 +1030 Subject: qsort: elf_sort_sections use of target_index elf_sort_sections tried to ensure a stable qsort by using target_index as the final comparison, but target_index hasn't been set by anything at the time elf_sort_sections was run. This patch arrange to have target_index set. * elf.c (_bfd_elf_map_sections_to_segments): Init target_index for sections about to be sorted. (assign_file_positions_for_load_sections): Likewise. (elf_sort_sections): Don't bother optimising both TOEND case. * elflink.c (bfd_elf_final_link): Reset target_index. --- bfd/ChangeLog | 8 ++++++++ bfd/elf.c | 21 +++++++++++---------- bfd/elflink.c | 4 ++++ 3 files changed, 23 insertions(+), 10 deletions(-) (limited to 'bfd') diff --git a/bfd/ChangeLog b/bfd/ChangeLog index e9c1758..6a5f673 100644 --- a/bfd/ChangeLog +++ b/bfd/ChangeLog @@ -1,5 +1,13 @@ 2019-10-14 Alan Modra + * elf.c (_bfd_elf_map_sections_to_segments): Init target_index + for sections about to be sorted. + (assign_file_positions_for_load_sections): Likewise. + (elf_sort_sections): Don't bother optimising both TOEND case. + * elflink.c (bfd_elf_final_link): Reset target_index. + +2019-10-14 Alan Modra + * elflink.c (elf_get_linked_section_vma): Delete. (compare_link_order): Use elf_linked_to_section and sort by lma, size, and id. diff --git a/bfd/elf.c b/bfd/elf.c index cbec426..314c866 100644 --- a/bfd/elf.c +++ b/bfd/elf.c @@ -4703,6 +4703,10 @@ _bfd_elf_map_sections_to_segments (bfd *abfd, struct bfd_link_info *info) { if ((s->flags & SEC_ALLOC) != 0) { + /* target_index is unused until bfd_elf_final_link + starts output of section symbols. Use it to make + qsort stable. */ + s->target_index = i; sections[i] = s; ++i; /* A wrapping section potentially clashes with header. */ @@ -5270,14 +5274,7 @@ elf_sort_sections (const void *arg1, const void *arg2) if (TOEND (sec1)) { - if (TOEND (sec2)) - { - /* If the indices are the same, do not return 0 - here, but continue to try the next comparison. */ - if (sec1->target_index - sec2->target_index != 0) - return sec1->target_index - sec2->target_index; - } - else + if (!TOEND (sec2)) return 1; } else if (TOEND (sec2)) @@ -5479,8 +5476,12 @@ assign_file_positions_for_load_sections (bfd *abfd, if (m->count > 1 && !(elf_elfheader (abfd)->e_type == ET_CORE && m->p_type == PT_NOTE)) - qsort (m->sections, (size_t) m->count, sizeof (asection *), - elf_sort_sections); + { + for (i = 0; i < m->count; i++) + m->sections[i]->target_index = i; + qsort (m->sections, (size_t) m->count, sizeof (asection *), + elf_sort_sections); + } /* An ELF segment (described by Elf_Internal_Phdr) may contain a number of sections with contents contributing to both p_filesz diff --git a/bfd/elflink.c b/bfd/elflink.c index fedaf4b..bfd0f01 100644 --- a/bfd/elflink.c +++ b/bfd/elflink.c @@ -12048,6 +12048,10 @@ bfd_elf_final_link (bfd *abfd, struct bfd_link_info *info) goto error_return; } + /* _bfd_elf_compute_section_file_positions makes temporary use + of target_index. Reset it. */ + o->target_index = 0; + /* Now, reset REL_COUNT and REL_COUNT2 so that we can use them to count upwards while actually outputting the relocations. */ esdo->rel.count = 0; -- cgit v1.1