diff options
Diffstat (limited to 'ld/ldlang.c')
| -rw-r--r-- | ld/ldlang.c | 66 |
1 files changed, 49 insertions, 17 deletions
diff --git a/ld/ldlang.c b/ld/ldlang.c index 888082147a1..b38d9a0057f 100644 --- a/ld/ldlang.c +++ b/ld/ldlang.c @@ -4858,6 +4858,7 @@ lang_size_sections_1 } else { + bfd_vma savedot; if (os->addr_tree == NULL) { /* No address specified for this section, get one @@ -4914,21 +4915,45 @@ lang_size_sections_1 section_alignment = os->section_alignment; /* Align to what the section needs. */ + savedot = newdot; if (section_alignment > 0) - { - bfd_vma savedot = newdot; - newdot = align_power (newdot, section_alignment); + newdot = align_power (newdot, section_alignment); - dotdelta = newdot - savedot; - if (dotdelta != 0 - && (config.warn_section_align - || os->addr_tree != NULL) - && expld.phase != lang_mark_phase_enum) - einfo (_("%P: warning: changing start of section" - " %s by %lu bytes\n"), - os->name, (unsigned long) dotdelta); + if (expld.dataseg.first_sec == os->bfd_section) + { + /* If a padding in file will be used for PT_GNU_RELRO + segment, check if we can reduce the padding by + increase the address of the first relro section. + It is a tradeoff between memory size and file size. + We only do it if file size will be reduced by more + than maximum page minus a page and memory size will + be increased by less than a page. */ + bfd_vma pad + = ((newdot - expld.dataseg.min_base) + % expld.dataseg.maxpagesize); + if (pad) + { + bfd_vma nextdot + = expld.dataseg.maxpagesize - pad; + nextdot = align_power (newdot + nextdot, + section_alignment); + if (((nextdot - newdot) + < expld.dataseg.pagesize) + && pad > (expld.dataseg.maxpagesize + - expld.dataseg.pagesize)) + newdot = nextdot; + } } + dotdelta = newdot - savedot; + if (dotdelta != 0 + && (config.warn_section_align + || os->addr_tree != NULL) + && expld.phase != lang_mark_phase_enum) + einfo (_("%P: warning: changing start of section" + " %s by %lu bytes\n"), + os->name, (unsigned long) dotdelta); + bfd_set_section_vma (0, os->bfd_section, newdot); os->bfd_section->output_offset = 0; @@ -5409,16 +5434,21 @@ lang_size_sections (bfd_boolean *relax, bfd_boolean check_regions) and DATA_SEGMENT_RELRO_END can cause excessive padding to be inserted at DATA_SEGMENT_RELRO_END. Try to start a bit lower so that the section alignments will fit in. */ - asection *sec; + asection *sec, *first_sec = NULL; unsigned int max_alignment_power = 0; /* Find maximum alignment power of sections between DATA_SEGMENT_ALIGN and DATA_SEGMENT_RELRO_END. */ - for (sec = link_info.output_bfd->sections; sec; sec = sec->next) - if (sec->vma >= expld.dataseg.base - && sec->vma < expld.dataseg.relro_end - && sec->alignment_power > max_alignment_power) - max_alignment_power = sec->alignment_power; + for (sec = link_info.output_bfd->sections; + sec && sec->vma < expld.dataseg.relro_end; + sec = sec->next) + if (sec->vma >= expld.dataseg.base) + { + if (first_sec == NULL) + first_sec = sec; + if (sec->alignment_power > max_alignment_power) + max_alignment_power = sec->alignment_power; + } if (((bfd_vma) 1 << max_alignment_power) < expld.dataseg.pagesize) { @@ -5427,8 +5457,10 @@ lang_size_sections (bfd_boolean *relax, bfd_boolean check_regions) simply subtracting 1 << max_alignment_power which is what we used to do here. */ expld.dataseg.base &= ~((1 << max_alignment_power) - 1); + expld.dataseg.first_sec = first_sec; lang_reset_memory_regions (); one_lang_size_sections_pass (relax, check_regions); + expld.dataseg.first_sec = NULL; } } link_info.relro_start = expld.dataseg.base; |