Fix a host of problems related to adjustment of
symbol values and sizes when relaxing for avr.
1. Adjust symbol size first before adjusting symbol
value. Otherwise, a symbol whose value just got adjusted to the
relaxed address also ends up getting resized. See pr21404-1.s.
2. Reduce symbol sizes only if their span is below an
alignment boundary. Otherwise, the size gets decremented once when the
actual instruction is relaxed and padding bytes are added, and again
when the padding bytes are deleted (if padding ends up being unnecessary).
pr21404-2.s addresses that, and this bug is really the root cause of PR21404.
3. Adjust all symbol values before an alignment boundary.
Previous code did not adjust symbol values if they fell in the
would-be padded area, resulting in incorrect symbol values in some
cases (see pr21404-3.s).
4. Increase symbol sizes if alignment directives require so.
As pr21404-4.s shows
.global nonzero_sym
L1:
jmp L1
nonzero_sym:
nop
nop
.p2align 2
.size nonzero_sym, .-nonzero_sym
The two nops satisfy the 4 byte alignment at assembly time and
therefore the size of nonzero_sym is 4. Relaxation shortens
the 4 byte jmp to a 2 byte rjmp, and to satisfy 4 byte alignment
the code places 2 extra padding bytes after the nops, increasing
nonzero_sym's size by 2. This wasn't handled before.
If the assembly code does not have any align directives, then the
boundary is the section size, and symbol values and sizes == boundary
should also get adjusted. To handle that case, add a did_pad variable
and use that to determine whether it should use < boundary or <= boundary.
Also get rid of reloc_toaddr, which is now redundant. toaddr is now not
adjusted to handle the above case - the newly added
did_pad variable does the job.
pr21404-{5,6,7,8} are the same testcases written for local symbols, as
the code handles them slightly differently.
We've been telling people that the riscv32-* and riscv64-* toolchains
are exactly the same, but it turns out we were lying: the riscv32-* BFD
doesn't handle 64-bit objects. This fixes that difference, so the ports
are actually the same.
bfd/ChangeLog
2017-05-01 Palmer Dabbelt <palmer@dabbelt.com>
* config.bfd (riscv32-*): Enable rv64.
The commit to "Always descend into output section statements in
lang_do_assignments" meant that linker script symbols were not
bfd_link_hash_new when ld called bfd_elf_record_link_assignment.
This patch corrects that problem by testing h->non_elf instead.
PR 21384
* elflink.c (bfd_elf_link_mark_dynamic_symbol): Test h->non_elf
rather than h->root.type == bfd_link_hash_new.
(bfd_elf_record_link_assignment): Similarly, call
bfd_elf_link_mark_dynamic_symbol when h->non_elf.
The existing reloc offset range tests didn't catch small negative
offsets less than the size of the reloc field.
PR 21432
* reloc.c (reloc_offset_in_range): New function.
(bfd_perform_relocation, bfd_install_relocation): Use it.
(_bfd_final_link_relocate): Likewise.
Since the GOT procedure linkage table is supported only if plt_got
isn't NULL, we need to check plt_got before using it.
* elf32-i386.c (elf_i386_allocate_dynrelocs): Check plt_got
before using .plt.got.
* elf64-x86-64.c (elf_x86_64_allocate_dynrelocs): Likewise.
Use
if (htab->elf.splt->size == 0)
htab->elf.splt->size = GET_PLT_ENTRY_SIZE (output_bfd);
instead of
if (htab->elf.splt->size == 0)
htab->elf.splt->size += GET_PLT_ENTRY_SIZE (output_bfd);
* elf64-x86-64.c (elf_x86_64_size_dynamic_sections): Use "="
instead of "+=" to update 0.
This patch creates dynamic sections in i386/x86-64 create_dynamic_sections
instead of creating them on demend. Linker will strip them if they are
empty. It changes order in x86-64 .eh_frame section. The extra DW_CFA_nop
paddings is due to
https://sourceware.org/bugzilla/show_bug.cgi?id=21441
bfd/
* elf32-i386.c (elf_i386_create_dynamic_sections): Create the
.plt.got section here.
(elf_i386_check_relocs): Don't create the .plt.got section.
* elf64-x86-64.c (elf_x86_64_create_dynamic_sections): Create
the .plt.got and .plt.bnd sections here.
(elf_x86_64_check_relocs): Don't create the .plt.got nor
.plt.bnd sections.
ld/
* testsuite/ld-x86-64/pr21038a.d: Update DW_CFA_nop paddings
in .eh_frame section.
* testsuite/ld-x86-64/pr21038c.d: Update .eh_frame order.
has_bnd_reloc was added to elf_x86_64_link_hash_entry track BND
relocations by
commit 0ff2b86e7c
Author: H.J. Lu <hjl.tools@gmail.com>
Date: Wed Nov 20 09:01:04 2013 -0800
Create the second PLT for BND relocations
Since BND relocations have been deprecated by
commit d258b82828
Author: Igor Zamyatin <igor.zamyatin@intel.com>
Date: Tue Nov 18 10:52:36 2014 +0300
Add -z bndplt to generate BND prefix in PLT entries
This patch removes has_bnd_reloc from elf_x86_64_link_hash_entry and
checks bndplt instead of has_bnd_reloc.
* elf64-x86-64.c (elf_x86_64_link_hash_entry): Remove
has_bnd_reloc.
(elf_x86_64_link_hash_newfunc): Don't clear has_bnd_reloc.
(elf_x86_64_copy_indirect_symbol): Don't copy has_bnd_reloc.
(elf_x86_64_check_relocs): Don't set has_bnd_reloc.
(elf_x86_64_finish_dynamic_symbol): Check bndplt instead of
has_bnd_reloc.
Remove has_bnd_reloc
Change setup_gnu_properties to return the first relocatable ELF input
with GNU properties so that a backend can make decision based on GNU
properties.
* elf-bfd.h (elf_backend_data): Change setup_gnu_properties
to return bfd *.
(_bfd_elf_link_setup_gnu_properties): Return bfd *.
* elf-properties.c (_bfd_elf_link_setup_gnu_properties): Return
the first relocatable ELF input with GNU properties.
Experimental support for moving symbols defined in .eh_frame as their
CIEs/FDEs are edited or merged.
* elf-bfd.h (struct eh_cie_fde): Add aug_str_len and aug_data_len.
(_bfd_elf_adjust_eh_frame_global_symbol): Declare.
* elf-eh-frame.c (_bfd_elf_parse_eh_frame): Set aug_str_len and
aug_data_len.
(offset_adjust): New function.
(_bfd_elf_adjust_eh_frame_global_symbol): Likewise.
(adjust_eh_frame_local_symbols): Likewise.
(_bfd_elf_discard_section_eh_frame): Call adjust_eh_frame_local_symbols
after changing anything. Return true if anything changed.
* elflink.c (bfd_elf_discard_info): If .eh_frame changed, call
_bfd_elf_adjust_eh_frame_global_symbol for globals.
This is really just cosmetic, but it does protect a little from
accidentally reading a stale value.
* elflink.c (_bfd_elf_link_hash_hide_symbol): Clear dynstr_index
when force_local.
This patch fixes a number of cases where -z nodynamic-undefined-weak
was not effective in preventing dynamic relocations or linkage stubs.
* elf32-ppc.c (UNDEFWEAK_NO_DYNAMIC_RELOC): Define.
(ppc_elf_select_plt_layout, ppc_elf_tls_setup): Use it.
(ppc_elf_adjust_dynamic_symbol, allocate_dynrelocs): Likewise.
(ppc_elf_relocate_section): Likewise. Delete silly optimisation
for undef and undefweak dyn_relocs.
* elf64-ppc.c (UNDEFWEAK_NO_DYNAMIC_RELOC): Define.
(ppc64_elf_adjust_dynamic_symbol, ppc64_elf_tls_setup): Use it.
(allocate_got, allocate_dynrelocs): Likewise.
(ppc64_elf_relocate_section): Likewise.
x86, PLT relocation may contain R_386_TLS_DESC or R_X86_64_TLSDESC
even though there is no real PLT. We need to add DT_PLTRELSZ, DT_PLTREL
and DT_JMPREL if there is a .rel.plt/.rela.plt section.
bfd/
* elf32-i386.c (elf_i386_size_dynamic_sections): Alwasys add
DT_PLTRELSZ, DT_PLTREL and DT_JMPREL for .rel.plt section.
* elf64-x86-64.c (elf_x86_64_size_dynamic_sections): Alwasys
add DT_PLTRELSZ, DT_PLTREL and DT_JMPREL for .rela.plt section.
ld/
* testsuite/ld-i386/tlsdesc2.d: New test.
* testsuite/ld-x86-64/tlsdesc2.d: Likewise.
Complement commit e17b0c351f ("MIPS/BFD: Respect the ELF gABI dynamic
symbol table sort requirement") and correct an inconsistency in dynamic
symbol accounting data causing an assertion failure in the MIPS backend:
ld: BFD (GNU Binutils) 2.28.51.20170330 assertion fail
../../binutils-gdb/bfd/elfxx-mips.c:3860
in the course of making a GOT entry in a static binary to satisfy a GOT
relocation present in input, due to the local dynamic symbol count not
having been established.
To do so let backends request `_bfd_elf_link_renumber_dynsyms' to be
always called, rather than where a dynamic binary is linked only, and
then make this request in the MIPS backend.
bfd/
PR ld/21334
* elf-bfd.h (elf_backend_data): Add `always_renumber_dynsyms'
member.
* elfxx-target.h [!elf_backend_always_renumber_dynsyms]
(elf_backend_always_renumber_dynsyms): Define.
(elfNN_bed): Initialize `always_renumber_dynsyms' member.
* elfxx-mips.h (elf_backend_always_renumber_dynsyms): Define.
* elflink.c (bfd_elf_size_dynamic_sections): Also call
`_bfd_elf_link_renumber_dynsyms' if the backend has requested
it.
(bfd_elf_size_dynsym_hash_dynstr): Likewise.
ld/
PR ld/21334
* testsuite/ld-mips-elf/pr21334.dd: New test.
* testsuite/ld-mips-elf/pr21334.gd: New test.
* testsuite/ld-mips-elf/pr21334.ld: New test linker script.
* testsuite/ld-mips-elf/pr21334.s: New test source.
* testsuite/ld-mips-elf/mips-elf.exp: Run the new tests.
Consistently call `_bfd_elf_link_renumber_dynsyms' only if linking a
dynamic binary, complementing code in `bfd_elf_size_dynsym_hash_dynstr'
and commit ccabcbe51e ("New attempt at fixing MIPS --gc-sections et
al."), <https://sourceware.org/ml/binutils/2005-08/msg00258.html>.
bfd/
* elflink.c (bfd_elf_size_dynamic_sections): Only call
`_bfd_elf_link_renumber_dynsyms' after section GC if dynamic
sections have been created.
Force symbol dynamic if it isn't undefined weak. Generate relative
relocation for GOT reference against non-dynamic symbol in PIC to
avoid unnecessary dynamic symbols.
bfd/
* elf64-x86-64.c (elf_x86_64_link_hash_entry): Add
no_finish_dynamic_symbol.
(elf_x86_64_link_hash_newfunc): Set no_finish_dynamic_symbol to
0.
(elf_x86_64_allocate_dynrelocs): If a symbol isn't undefined
weak symbol, don't make it dynamic.
(elf_x86_64_relocate_section): If a symbol isn't dynamic in PIC,
set no_finish_dynamic_symbol and generate R_X86_64_RELATIVE
relocation for GOT reference.
(elf_x86_64_finish_dynamic_symbol): Abort if
no_finish_dynamic_symbol isn't 0.
ld/
* testsuite/ld-x86-64/no-plt.exp: Also check no-plt-1e.nd.
* testsuite/ld-x86-64/no-plt-1e.nd: New file.
Force symbol dynamic if it isn't undefined weak. Generate R_386_RELATIVE
relocation for R_386_GOT32 relocation against non-dynamic symbol in PIC.
PR ld/21402
* elf32-i386.c (elf_i386_allocate_dynrelocs): If a symbol isn't
undefined weak symbol, don't make it dynamic.
(elf_i386_relocate_section): If a symbol isn't dynamic in PIC,
set no_finish_dynamic_symbol and generate R_386_RELATIVE
relocation for R_386_GOT32.
commit a27e437177
Author: Roland McGrath <roland@gnu.org>
Date: Thu Jul 28 22:35:15 2011 +0000
BFD vector for elf32-i386-nacl:
changed ELF_MAXPAGESIZE to 0x10000 for VxWorks. This patch fixes it
and updated testsuite/ld-i386/vxworks2.sd to add space for program
headers.
bfd/
PR ld/21425
* elf32-i386.c (ELF_MAXPAGESIZE): Set to 0x1000 for VxWorks.
ld/
PR ld/20815
* testsuite/ld-i386/vxworks2.sd: Add space for program headers.
This patch fixes an assumption made by code that runs for objcopy and
strip, that SHT_REL/SHR_RELA sections are always named starting with a
.rel/.rela prefix. I'm also modifying the interface for
elf_backend_get_reloc_section, so any backend function just needs to
handle name mapping.
PR 21412
* elf-bfd.h (struct elf_backend_data <get_reloc_section>): Change
parameters and comment.
(_bfd_elf_get_reloc_section): Delete.
(_bfd_elf_plt_get_reloc_section): Declare.
* elf.c (_bfd_elf_plt_get_reloc_section, elf_get_reloc_section):
New functions. Don't blindly skip over assumed .rel/.rela prefix.
Extracted from..
(_bfd_elf_get_reloc_section): ..here. Delete.
(assign_section_numbers): Call elf_get_reloc_section.
* elf64-ppc.c (elf_backend_get_reloc_section): Define.
* elfxx-target.h (elf_backend_get_reloc_section): Update.
GOT reference to global symbol in PIE will lead to dynamic symbol. It
becomes a problem when "time" or "times" is defined as a variable in
an executable, clashing with functions of the same name in libc. If
a symbol isn't undefined weak symbol, don't make it dynamic in PIE and
generate R_386_RELATIVE relocation.
bfd/
PR ld/21402
* elf32-i386.c (elf_i386_link_hash_entry): Add
no_finish_dynamic_symbol.
(elf_i386_link_hash_newfunc): Set no_finish_dynamic_symbol to 0.
(elf_i386_allocate_dynrelocs): If a symbol isn't undefined weak
symbol, don't make it dynamic in PIE.
(elf_i386_relocate_section): If a symbol isn't dynamic in PIE,
set no_finish_dynamic_symbol and generate R_386_RELATIVE
relocation for R_386_GOT32
(elf_i386_finish_dynamic_symbol): Abort if no_finish_dynamic_symbol
isn't 0.
ld/
PR ld/21402
* testsuite/ld-elf/indirect.exp: Don't skip PIE indirect5 and
indirect6 tests on i386.
When -static -E/--dynamic-list are passed to linker, linker may create
executable with dynamic sections which aren't supported by run-time.
We require --no-dynamic-linker together with -static -E/--dynamic-list
before adding dynamic symbol table to static executable.
bfd/
PR ld/19617
PR ld/21086
* elflink.c (elf_link_add_object_symbols): Require
--no-dynamic-linker with -E/--dynamic-list when creating
dynamic sections.
ld/
PR ld/19617
PR ld/21086
* testsuite/ld-elf/pr19617a.d: Pass --no-dynamic-linker to ld.
* testsuite/ld-elf/pr19617b.d: Likewise.
* testsuite/ld-elf/pr19617c.d: Likewise.
*testsuite/ld-i386/pr19636-4d.d: Likewise.
* testsuite/ld-elf/readelf.exp: Pass --no-dynamic-linker to ld
with --export-dynamic.
* testsuite/ld-elf/shared.exp: Pass --no-dynamic-linker to ld
with -E.
Do not require forced local (STB_LOCAL) symbols to have a definition in
a regular file to be considered to resolve local to the current module,
matching `elf_link_renumber_local_hash_table_dynsyms'. In the absence
of a regular definition any reference to a STB_LOCAL symbol will have to
be garbage collected along with the undefined symbol itself, or the link
will eventually fail. Either way the symbol concerned is not going to
be external.
bfd/
* elflink.c (_bfd_elf_symbol_refs_local_p): Always return TRUE
if forced local.
Move the comment about dynamic symbol sorting next to where it happens.
bfd/
* elfxx-mips.c (_bfd_mips_elf_final_link): Reorder comment about
dynamic symbol sorting.
We need to make an IR symbol visible if it is defined in an IR object
and referenced in a dynamic object. When --as-needed is used, since
linker removes the IR symbol reference of the dynamic object if the
dynamic object isn't needed in the first pass, the IR definition isn't
visible to the dynamic object even if the dynamic object becomes needed
in the second pass. Add dynamic_ref_after_ir_def to bfd_link_hash_entry
to track IR symbol which is defined in an IR object and later referenced
in a dynamic object. dynamic_ref_after_ir_def is preserved when restoring
the symbol table for unneeded dynamic object.
bfd/
PR ld/21382
* elflink.c (elf_link_add_object_symbols): Preserve
dynamic_ref_after_ir_def when restoring the symbol table for
unneeded dynamic object.
include/
PR ld/21382
* bfdlink.h (bfd_link_hash_entry): Add dynamic_ref_after_ir_def.
ld/
PR ld/21382
* plugin.c (is_visible_from_outside): Symbol may be visible
from outside if dynamic_ref_after_ir_def is set.
(plugin_notice): Set dynamic_ref_after_ir_def if the symbol is
defined in an IR object and referenced in a dynamic object.
* testsuite/ld-plugin/lto.exp: Run PR ld/21382 tests.
* testsuite/ld-plugin/pr21382a.c: New file.
* testsuite/ld-plugin/pr21382b.c: Likewise.
Since undefined IFUNC symbol is treated as normal FUNC symbol, don't
abort on undefined IFUNC symbol in the second PLT.
bfd/
PR ld/21401
* elf64-x86-64.c (elf_x86_64_finish_dynamic_symbol): Don't abort
on on undefined IFUNC symbol in the second PLT.
ld/
PR ld/21401
* testsuite/ld-ifunc/ifunc.exp: Add a libtest-2-now.so test with
-z now.
-z nodynamic-undefined-weak is only implemented for x86. (The sparc
backend has some support code but doesn't enable the option by
including ld/emulparams/dynamic_undefined_weak.sh, and since the
support looks like it may be broken I haven't enabled it.) This patch
adds the complementary -z dynamic-undefined-weak, extends both options
to affect building of shared libraries as well as executables, and
adds support for the option on powerpc.
include/
* bfdlink.h (struct bfd_link_info <dynamic_undefined_weak>):
Revise comment.
bfd/
* elflink.c (_bfd_elf_adjust_dynamic_symbol): Hide undefweak
or make dynamic for info->dynamic_undefined_weak 0 and 1.
* elf32-ppc.c:Formatting.
(ensure_undefweak_dynamic): Don't make dynamic when
info->dynamic_undefined_weak is zero.
(allocate_dynrelocs): Discard undefweak dyn_relocs for
info->dynamic_undefined_weak. Discard undef dyn_relocs when
not default visibility. Discard undef and undefweak
dyn_relocs earlier.
(ppc_elf_relocate_section): Adjust to suit.
* elf64-ppc.c: Formatting.
(ensure_undefweak_dynamic): Don't make dynamic when
info->dynamic_undefined_weak is zero.
(allocate_dynrelocs): Discard undefweak dyn_relocs for
info->dynamic_undefined_weak. Discard them earlier.
ld/
* ld.texinfo (dynamic-undefined-weak): Document.
(nodynamic-undefined-weak): Document that this option now can
be used with shared libs.
* emulparams/dynamic_undefined_weak.sh: Support -z
dynamic-undefined-weak.
* emulparams/elf32ppccommon.sh: Include dynamic_undefined_weak.sh.
* testsuite/ld-undefined/weak-undef.exp (undef_weak_so),
(undef_weak_exe): New. Use them. Add -z dynamic-undefined-weak
and -z nodynamic-undefined-weak tests.
* Makefile.am: Update powerpc dependencies.
* Makefile.in: Regenerate.
GDB Administrator
Senthil Kumar Selvaraj
Palmer Dabbelt
Alan Modra
H.J. Lu
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Maciej W. Rozycki
Wedson Almeida Filho