diff options
| -rw-r--r-- | bfd/ChangeLog | 5 | ||||
| -rw-r--r-- | bfd/elflink.c | 56 |
2 files changed, 49 insertions, 12 deletions
diff --git a/bfd/ChangeLog b/bfd/ChangeLog index 6a5f673..bb6c907 100644 --- a/bfd/ChangeLog +++ b/bfd/ChangeLog @@ -1,5 +1,10 @@ 2019-10-14 Alan Modra <amodra@gmail.com> + * elflink.c (elf_sort_symbol): Sort on type and name as well. + (elf_link_add_object_symbols): Style fix. + +2019-10-14 Alan Modra <amodra@gmail.com> + * elf.c (_bfd_elf_map_sections_to_segments): Init target_index for sections about to be sorted. (assign_file_positions_for_load_sections): Likewise. diff --git a/bfd/elflink.c b/bfd/elflink.c index bfd0f01..9d7f69a 100644 --- a/bfd/elflink.c +++ b/bfd/elflink.c @@ -3587,27 +3587,60 @@ on_needed_list (const char *soname, return FALSE; } -/* Sort symbol by value, section, and size. */ +/* Sort symbol by value, section, size, and type. */ static int elf_sort_symbol (const void *arg1, const void *arg2) { const struct elf_link_hash_entry *h1; const struct elf_link_hash_entry *h2; bfd_signed_vma vdiff; + int sdiff; + const char *n1; + const char *n2; h1 = *(const struct elf_link_hash_entry **) arg1; h2 = *(const struct elf_link_hash_entry **) arg2; vdiff = h1->root.u.def.value - h2->root.u.def.value; if (vdiff != 0) return vdiff > 0 ? 1 : -1; - else - { - int sdiff = h1->root.u.def.section->id - h2->root.u.def.section->id; - if (sdiff != 0) - return sdiff > 0 ? 1 : -1; - } + + sdiff = h1->root.u.def.section->id - h2->root.u.def.section->id; + if (sdiff != 0) + return sdiff; + + /* Sort so that sized symbols are selected over zero size symbols. */ vdiff = h1->size - h2->size; - return vdiff == 0 ? 0 : vdiff > 0 ? 1 : -1; + if (vdiff != 0) + return vdiff > 0 ? 1 : -1; + + /* Sort so that STT_OBJECT is selected over STT_NOTYPE. */ + if (h1->type != h2->type) + return h1->type - h2->type; + + /* If symbols are properly sized and typed, and multiple strong + aliases are not defined in a shared library by the user we + shouldn't get here. Unfortunately linker script symbols like + __bss_start sometimes match a user symbol defined at the start of + .bss without proper size and type. We'd like to preference the + user symbol over reserved system symbols. Sort on leading + underscores. */ + n1 = h1->root.root.string; + n2 = h2->root.root.string; + while (*n1 == *n2) + { + if (*n1 == 0) + break; + ++n1; + ++n2; + } + if (*n1 == '_') + return -1; + if (*n2 == '_') + return 1; + + /* Final sort on name selects user symbols like '_u' over reserved + system symbols like '_Z' and also will avoid qsort instability. */ + return *n1 - *n2; } /* This function is used to adjust offsets into .dynstr for @@ -5345,8 +5378,8 @@ error_free_dyn: defined symbol, search time for N weak defined symbols will be O(N^2). Binary search will cut it down to O(NlogN). */ amt = extsymcount; - amt *= sizeof (struct elf_link_hash_entry *); - sorted_sym_hash = (struct elf_link_hash_entry **) bfd_malloc (amt); + amt *= sizeof (*sorted_sym_hash); + sorted_sym_hash = bfd_malloc (amt); if (sorted_sym_hash == NULL) goto error_return; sym_hash = sorted_sym_hash; @@ -5366,8 +5399,7 @@ error_free_dyn: } } - qsort (sorted_sym_hash, sym_count, - sizeof (struct elf_link_hash_entry *), + qsort (sorted_sym_hash, sym_count, sizeof (*sorted_sym_hash), elf_sort_symbol); while (weaks != NULL) |