When processing a section that is a member of a group, the group
that contains it is looked up using a linear search. The resulting
O(n^2) complexity causes significant performance issues when
dealing with object files with very many groups.
By remembering the index of the last found group and restarting
the next search from that index, the search instead becomes O(n)
in common cases.
* elf.c (setup_group): Optimize search for group by remembering
last found group and restarting search at that index.
* elf-bfd.h (struct elf_obj_tdata): Add group_search_offset field.
The default should be bfd_link_common_skip_none, as in the original
patch at https://sourceware.org/ml/binutils/2002-07/msg00717.html
* aoutx.h (aout_link_check_ar_symbols): Remove default and handle
bfd_link_common_skip_none in switch.
PowerPC64 has its own mark_dynamic_ref, which needs the same change as
made by d664fd41e1 to the generic ELF version. Some other targets
discard more than just .data, so allow for that too in expected ld
messages.
bfd/
PR ld/22649
* elf64-ppc.c (ppc64_elf_gc_mark_dynamic_ref): Ignore dynamic
references on forced local symbols.
ld/
PR ld/22649
* testsuite/ld-elf/pr22649.msg: Allow other messages.
* testsuite/ld-elf/shared.exp: Check that --gc-sections is
supported before running ld/22649 tests.
One of assertions in _bfd_mips_elf_final_link could be triggered by
a combination of input files and a linker script. This happens when
either the input doesn't contain .reginfo section or when this section
is oversized. This patch replaces the assertion with a more useful
error message.
* elfxx-mips.c (_bfd_mips_elf_final_link): Notify user when
.reginfo section has wrong size.
When generating separate code LOAD segment, create a new LOAD segment
if the previous section contains text and the current section doesn't
or vice versa:
Elf file type is DYN (Shared object file)
Entry point 0x200020
There are 7 program headers, starting at offset 52
Program Headers:
Type Offset VirtAddr PhysAddr FileSiz MemSiz Flg Align
LOAD 0x000000 0x00000000 0x00000000 0x00200 0x00200 R 0x200000
LOAD 0x200000 0x00200000 0x00200000 0x00036 0x00036 R E 0x200000
LOAD 0x400000 0x00400000 0x00400000 0x00064 0x00064 R 0x200000
LOAD 0x400f80 0x00600f80 0x00600f80 0x000a0 0x000a0 RW 0x200000
DYNAMIC 0x400f80 0x00600f80 0x00600f80 0x00080 0x00080 RW 0x4
GNU_STACK 0x000000 0x00000000 0x00000000 0x00000 0x00000 RW 0x10
GNU_RELRO 0x400f80 0x00600f80 0x00600f80 0x00080 0x00080 R 0x1
Section to Segment mapping:
Segment Sections...
00 .hash .gnu.hash .dynsym .dynstr .rela.plt
01 .plt .text
02 .rodata .eh_frame
03 .dynamic .got.plt
04 .dynamic
05
06 .dynamic
to prevent fetching or executing data in code pages as instructions.
Also don't put a writable section in a read-only segment if there is a
RELRO segment.
Since code segment is aligned and padded to the maximum page size on
disk, the minimum file size is bigger than the maximum page size which
is 2MB (0x200000):
-rwxr-xr-x 1 hjl hjl 4201932 Jan 10 10:41 libfoo.so
"-z max-page-size=0x1000" can be used to reduce the maximum page size to
4KB (0x1000):
-rwxr-xr-x 1 hjl hjl 15820 Jan 10 10:44 libfoo.so
PR ld/22393
* elf.c (_bfd_elf_map_sections_to_segments): When generating
separate code and read-only data LOAD segments, create a new
LOAD segment if the previous section contains text and the
current section doesn't or vice versa. Don't put a writable
section in a read-only segment if there is a RELRO segment.
We should ignore dynamic references on forced local symbols during
garbage collection since they can never be referenced dynamically.
bfd/
PR ld/22649
* elflink.c (bfd_elf_gc_mark_dynamic_ref_symbol): Ignore dynamic
references on forced local symbols.
ld/
PR ld/22649
* testsuite/ld-elf/pr22649-1.s: New file.
* testsuite/ld-elf/pr22649-2a.s: Likewise.
* testsuite/ld-elf/pr22649-2b.s: Likewise.
* testsuite/ld-elf/pr22649.msg: Likewise.
* testsuite/ld-elf/shared.exp: Run ld/22649 tests.
We must keep all PREINIT_ARRAY, INIT_ARRAY as well as FINI_ARRAY sections
for ld -r --gc-sections.
bfd/
PR ld/22677
* elflink.c (bfd_elf_gc_sections): Keep all PREINIT_ARRAY,
INIT_ARRAY as well as FINI_ARRAY sections for ld -r --gc-sections.
ld/
PR ld/22677
* scripttempl/elf.sc (PREINIT_ARRAY): New.
Don't add .preinit_array for ld -r.
* testsuite/ld-elf/pr22677.d: New file.
* testsuite/ld-elf/pr22677.s: Likewise.
_bfd_elf_link_renumber_dynsyms is called twice by the linker. The
first call in bfd_elf_size_dynamic_sections is just to answer the
question as to whether there are there any dynamic symbols. The
second call in bfd_elf_size_dynsym_hash_dynstr sets the st_shndx value
that dynamic symbols will have. strip_excluded_output_sections is
called between these two calls. So sections seen on the first
_bfd_elf_link_renumber_dynsyms pass might differ from those seen on
the second pass. Unfortunately, that can result in a stripped
section's dynamic symbol being assigned a dynindx on the first pass
but not corrected to the final value (of zero, ie. not dynamic) on the
second pass. PowerPC, x86, mips, and most other targets that emit
dynamic section symbols, just test that section symbol dynindx is
non-zero before using a given section symbol in dynamic relocations.
This patch prevents _bfd_elf_link_renumber_dynsyms from setting any
section symbol dynindx on the first pass.
PR 22626
* elflink.c (_bfd_elf_link_renumber_dynsyms): Don't set section
dynindx when section_sym_count is NULL.
(bfd_elf_size_dynamic_sections): Pass NULL section_sym_count to
preliminary _bfd_elf_link_renumber_dynsyms call.
PR 22571
* archive.c (bfd_openr_next_archived_file): Extend the
documentation to note that it is necessary to call
bfd_check_format on the rrturned bfd before using it.
R_AARCH64_ABS64, R_AARCH64_ABS32 and R_AARCH64_ABS16 are data relocations
supported in AArch64 elf ABI.
R_AARCH64_ABS64 under LP64 is allowed in shared object and a dynamic relocation entry
will be generated. This allows the dynamic linker to do further symbol resolution.
R_AARCH64_ABS32 likewise is allowed in shared object, however under ILP32 abi.
The original behavior for R_AARCH64_ABS32 under LP64 is that, it's allowed
in shared object and silently resolved at static linking time.
No dynamic relocation entry is generate for it.
R_AARCH64_ABS16 is allowed in shared object under both L64 and ILP32.
It's resolved at static linking time as well.
Under LP64, the address should be 64-bit. R_AARCH64_ABS32 relocation indicates
an address that is only sized 32 bits which is meaningless in LP64 shared object.
It's useful to error out.
I have checked glibc dynamic linker code, R_AARCH64_ABS16 is not supported at all. So
R_AARCH64_ABS16 should be reject in shared object completely.
In this patch, R_AARCH64_ABS32 is rejected under LP64 in constant section of shared object.
R_AARCH64_ABS16 is rejected in constant section of shared object in both ABI.
This will sometimes provide useful information for buggy code.
This fixes these failures on 64 bit which currently occur when running
the Binutils testsuite with a default PIE compiler.
< FAIL: Build rdynamic-1
< FAIL: Build dynamic-1
< FAIL: Build pr22269-1
bfd/ChangeLog:
2017-12-13 Andreas Krebbel <krebbel@linux.vnet.ibm.com>
* elf64-s390.c (elf_s390_adjust_dynamic_symbol): Use
UNDEFWEAK_NO_DYNAMIC_RELOC.
(allocate_dynrelocs): Likewise.
(elf_s390_relocate_section): Check resolved_to_zero.
(elf_s390_finish_dynamic_symbol): Don't generate runtime reloc if
UNDEFWEAK_NO_DYNAMIC_RELOC.
