static bfd_vma
lang_size_relro_segment_1 (seg_align_type *seg)
{
- bfd_vma relro_end, desired_relro_base;
- asection *sec, *relro_sec = NULL;
+ bfd_vma relro_end, desired_end;
+ asection *sec, *prev_sec = NULL;
+ bool remove_page_gap = false;
unsigned int max_alignment_power = 0;
- bool seen_reloc_section = false;
- bool desired_relro_base_reduced = false;
/* Compute the expected PT_GNU_RELRO/PT_LOAD segment end. */
relro_end = ((seg->relro_end + seg->pagesize - 1)
& ~(seg->pagesize - 1));
/* Adjust by the offset arg of XXX_SEGMENT_RELRO_END. */
- desired_relro_base = relro_end - seg->relro_offset;
+ desired_end = relro_end - seg->relro_offset;
- /* For sections in the relro segment. */
+ /* For sections in the relro segment.. */
for (sec = link_info.output_bfd->section_last; sec; sec = sec->prev)
if ((sec->flags & SEC_ALLOC) != 0)
{
- /* Record the maximum alignment for all sections starting from
- the relro segment. */
if (sec->alignment_power > max_alignment_power)
max_alignment_power = sec->alignment_power;
if (sec->vma >= seg->base
&& sec->vma < seg->relro_end - seg->relro_offset)
{
- /* Where do we want to put the relro section so that the
- relro segment ends on the page bounary? */
+ /* Where do we want to put this section so that it ends as
+ desired? */
bfd_vma start, end, bump;
end = start = sec->vma;
if (!IS_TBSS (sec))
end += TO_ADDR (sec->size);
- bump = desired_relro_base - end;
+ bump = desired_end - end;
/* We'd like to increase START by BUMP, but we must heed
alignment so the increase might be less than optimum. */
start += bump;
start &= ~(((bfd_vma) 1 << sec->alignment_power) - 1);
/* This is now the desired end for the previous section. */
- desired_relro_base = start;
- relro_sec = sec;
- seen_reloc_section = true;
+ desired_end = start;
+ prev_sec = sec->prev;
}
- else if (seen_reloc_section)
+ }
+
+ seg->phase = exp_seg_relro_adjust;
+ ASSERT (desired_end >= seg->base);
+
+ for (; prev_sec; prev_sec = prev_sec->prev)
+ if ((prev_sec->flags & SEC_ALLOC) != 0)
+ {
+ if (prev_sec->alignment_power > max_alignment_power)
+ max_alignment_power = prev_sec->alignment_power;
+
+ if (prev_sec->size != 0)
{
- /* Stop searching if we see a non-relro section after seeing
- relro sections. */
+ /* The 1-page gap before the RELRO segment may be removed. */
+ remove_page_gap = ((prev_sec->vma + prev_sec->size
+ + seg->maxpagesize) < desired_end);
+
break;
}
}
- if (relro_sec != NULL
- && seg->maxpagesize >= (1U << max_alignment_power))
+ if (remove_page_gap)
{
- asection *prev_sec;
- bfd_vma prev_sec_end_plus_1_page;
-
- /* Find the first preceding load section. */
- for (prev_sec = relro_sec->prev;
- prev_sec != NULL;
- prev_sec = prev_sec->prev)
- if ((prev_sec->flags & SEC_ALLOC) != 0)
- break;
+ /* Find the maximum section alignment. */
+ for (sec = prev_sec; sec; sec = sec->prev)
+ if ((sec->flags & SEC_ALLOC) != 0
+ && sec->alignment_power > max_alignment_power)
+ max_alignment_power = sec->alignment_power;
- prev_sec_end_plus_1_page = (prev_sec->vma + prev_sec->size
- + seg->maxpagesize);
- if (prev_sec_end_plus_1_page < desired_relro_base)
+ /* Remove the 1-page gap before the RELRO segment only if the
+ maximum page size >= the maximum section alignment. */
+ if (seg->maxpagesize >= (1U << max_alignment_power))
{
- bfd_vma aligned_relro_base;
-
- desired_relro_base_reduced = true;
-
- /* Don't add the 1-page gap before the relro segment. Align
- the relro segment first. */
- aligned_relro_base = (desired_relro_base
- & ~(seg->maxpagesize - 1));
- if (prev_sec_end_plus_1_page < aligned_relro_base)
+ /* If the preceding section size is greater than the maximum
+ page size, subtract the maximum page size. Otherwise,
+ align the RELRO segment to the maximum page size. */
+ if (prev_sec->size > seg->maxpagesize)
{
- /* Subtract the maximum page size if therer is still a
- 1-page gap. */
- desired_relro_base -= seg->maxpagesize;
+ desired_end -= seg->maxpagesize;
relro_end -= seg->maxpagesize;
}
else
{
- /* Align the relro segment. */
- desired_relro_base = aligned_relro_base;
+ desired_end &= ~(seg->maxpagesize - 1);
relro_end &= ~(seg->maxpagesize - 1);
}
- }
- }
+ }
+ }
- seg->phase = exp_seg_relro_adjust;
- ASSERT (desired_relro_base_reduced
- || desired_relro_base >= seg->base);
- seg->base = desired_relro_base;
+ seg->base = desired_end;
return relro_end;
}
+++ /dev/null
-#as: --64
-#ld: -melf_x86_64 -shared -z relro -z now --hash-style=sysv -z max-page-size=0x1000 -z noseparate-code $NO_DT_RELR_LDFLAGS
-#readelf: -S -l --wide
-#target: x86_64-*-linux*
-
-There are 17 section headers, starting at offset 0x101228:
-
-Section Headers:
- \[Nr\] Name Type Address Off Size ES Flg Lk Inf Al
- \[ 0\] NULL 0000000000000000 000000 000000 00 0 0 0
- \[ 1\] .hash HASH 0000000000000120 000120 000018 04 A 2 0 8
- \[ 2\] .dynsym DYNSYM 0000000000000138 000138 000048 18 A 3 1 8
- \[ 3\] .dynstr STRTAB 0000000000000180 000180 00000a 00 A 0 0 1
- \[ 4\] .rela.dyn RELA 0000000000000190 000190 000018 18 A 2 0 8
- \[ 5\] .plt PROGBITS 00000000000001b0 0001b0 000010 10 AX 0 0 16
- \[ 6\] .plt.got PROGBITS 00000000000001c0 0001c0 000008 08 AX 0 0 8
- \[ 7\] .text PROGBITS 00000000000001c8 0001c8 00000c 00 AX 0 0 1
- \[ 8\] .eh_frame PROGBITS 00000000000001d8 0001d8 00006c 00 A 0 0 8
- \[ 9\] .init_array INIT_ARRAY 00000000000ffff8 0ffff8 000004 08 WA 0 0 8
- \[10\] .fini_array FINI_ARRAY 0000000000100000 100000 000100 08 WA 0 0 1048576
- \[11\] .dynamic DYNAMIC 0000000000100100 100100 000150 10 WA 3 0 8
- \[12\] .got PROGBITS 0000000000100250 100250 000020 08 WA 0 0 8
- \[13\] .data PROGBITS 0000000000101000 101000 000100 00 WA 0 0 1
- \[14\] .symtab SYMTAB 0000000000000000 101100 000078 18 15 3 8
- \[15\] .strtab STRTAB 0000000000000000 101178 000029 00 0 0 1
- \[16\] .shstrtab STRTAB 0000000000000000 1011a1 000080 00 0 0 1
-Key to Flags:
- W \(write\), A \(alloc\), X \(execute\), M \(merge\), S \(strings\), I \(info\),
- L \(link order\), O \(extra OS processing required\), G \(group\), T \(TLS\),
- C \(compressed\), x \(unknown\), o \(OS specific\), E \(exclude\),
- D \(mbind\), l \(large\), p \(processor specific\)
-
-Elf file type is DYN \(Shared object file\)
-Entry point 0x0
-There are 4 program headers, starting at offset 64
-
-Program Headers:
- Type Offset VirtAddr PhysAddr FileSiz MemSiz Flg Align
- LOAD 0x000000 0x0000000000000000 0x0000000000000000 0x000244 0x000244 R E 0x1000
- LOAD 0x0ffff8 0x00000000000ffff8 0x00000000000ffff8 0x001108 0x001108 RW 0x100000
- DYNAMIC 0x100100 0x0000000000100100 0x0000000000100100 0x000150 0x000150 RW 0x8
- GNU_RELRO 0x0ffff8 0x00000000000ffff8 0x00000000000ffff8 0x001008 0x001008 R 0x1
-
- Section to Segment mapping:
- Segment Sections...
- 00 .hash .dynsym .dynstr .rela.dyn .plt .plt.got .text .eh_frame
- 01 .init_array .fini_array .dynamic .got .data
- 02 .dynamic
- 03 .init_array .fini_array .dynamic .got
-#pass
projects / binutils-gdb.git / commitdiff