[bfd] Provide 8-byte minimum alignment for .plt section
This change increases the default alignment for the .plt section
from 4 bytes to 8 bytes. When function descriptors are 8-byte
aligned, they can be updated atomically on 32-bit hppa. This
helps with ordering issues on SMP machines. It also ensures
that descriptors reside on the same cache line. This reduces
the probability of a double TLB miss in a call.
2019-10-20 John David Anglin <danglin@gcc.gnu.org>
* elf32-hppa.c (elf32_hppa_size_dynamic_sections): Provide 8-byte
minimum alignment for .plt section.
This commit updates the import stubs to leave the pointer to the
function descriptor in register %r22. This provides a backup
mechanism for _dl_runtime_resolve to fixup descriptors during
lazy binding.
bfd/ChangeLog
2019-10-20 John David Anglin <danglin@gcc.gnu.org>
* elf32-hppa.c: Revise import stub sequences.
(LONG_BRANCH_STUB_SIZE): Define.
(LONG_BRANCH_SHARED_STUB_SIZE): Define.
(IMPORT_STUB_SIZE): Define.
(IMPORT_SHARED_STUB_SIZE): Define.
(EXPORT_STUB_SIZE): Define.
(plt_stub): Revise to not use register %r22.
(LDO_R1_R22): Define.
(LDW_R22_R21): Define.
(LDW_R22_R19): Define.
(hppa_build_one_stub): Update stub generation and use new defines.
(hppa_size_one_stub): Likewise.
Tamar Christina [Tue, 24 Sep 2019 13:46:17 +0000 (14:46 +0100)]
Arm: Fix out of range conditional branch (PR/24991)
The fix for PR12848 introduced an off by one error in the mask, this corrected
the negative overflows but not the positive overflows. As a result the
conditional branch instructions accepted a too wide positive immediate which
resulted in it corrupting the instruction during encoding.
The relocation I believe has been incorrectly named, to be consistent with the
other relocations it should have been named BRANCH21 which is why the masks for
it are confusing.
I've replaced the masks with a function out_of_range_p which should make it
harder to make such mistakes.
The mask for BL/BLX on Armv6t+ is also wrong, the extended range is 25-bits
and so the mask should be checking for 24-bits for positive overflow.
gas/ChangeLog:
PR gas/24991
* config/tc-arm.c (out_of_range_p): New.
(md_apply_fix): Use it in BFD_RELOC_THUMB_PCREL_BRANCH9,
BFD_RELOC_THUMB_PCREL_BRANCH12, BFD_RELOC_THUMB_PCREL_BRANCH20,
BFD_RELOC_THUMB_PCREL_BRANCH23, BFD_RELOC_THUMB_PCREL_BRANCH25
* testsuite/gas/arm/pr24991.d: New test.
* testsuite/gas/arm/pr24991.l: New test.
* testsuite/gas/arm/pr24991.s: New test.
Alan Modra [Wed, 9 Oct 2019 10:55:25 +0000 (21:25 +1030)]
PR25081, Discrepancy between VMA and LMA after ALIGN
The testcase in the PR has two empty output sections, .sec1 with an
ALIGN and symbol assignment, and .sec2 just with an empty input
section. The symbol assignment results in .sec1 being kept, but
because it is empty this section doesn't take space from the memory
region as you might expect from the ALIGN. Instead the next section
.sec2, has vma/lma as if .sec1 wasn't present. However, .sec2 is
discarded and os->ignored set, which unfortunately meant that dot
wasn't set from .sec2 vma. That in turn results in .sec2 lma being
set incorrectly. That vma/lma difference is then propagated to
.sec3 where it is seen as an overlap.
PR 25081
* ldlang.c (lang_size_sections_1): Set lma from section vma
rather than dot.
Szabolcs Nagy [Wed, 2 Oct 2019 18:46:46 +0000 (19:46 +0100)]
[PR ld/22263][PR ld/25056] arm: Avoid dynamic TLS relocs in PIE
Dynamic relocs are only needed in an executable for TLS symbols if
those are defined in an external module and even then TLS access
can be relaxed to use IE model instead of GD.
Several bfd_link_pic checks are turned into bfd_link_dll checks
to fix TLS handling in PIE, for the same fix some other targets
used !bfd_link_executable checks, but that includes relocatable
objects so dll seems safer (in most cases either should work, since
dynamic relocations are not applied in relocatable objects).
On arm* fixes
FAIL: Build pr22263-1
bfd/
PR ld/22263
PR ld/25056
* elf32-arm.c (elf32_arm_tls_transition): Use bfd_link_dll instead of
bfd_link_pic for TLS checks.
(elf32_arm_final_link_relocate): Likewise.
(allocate_dynrelocs_for_symbol): Likewise.
Alan Modra [Tue, 8 Oct 2019 13:41:28 +0000 (00:11 +1030)]
PR25079, "ar s" stopped working
's' is both a command and a modifier. If given as a command then we
aren't lacking an operation. I think the same goes when mri mode is
selected: any following command line used to be ignored.
PR 25079
* ar.c (decode_options): Don't try for command options if
write_armap or mri_mode is selected.
Alan Modra [Mon, 7 Oct 2019 02:51:02 +0000 (13:21 +1030)]
PowerPC TLS miscounting PLT for __tls_get_addr
ppc*_elf_tls_optimize decrements the PLT refcount for __tls_get_addr
when a GD or LD sequence can be optimized. Without tls marker relocs
this must be done when processing the argument setup relocations.
With marker relocs it's better done when processing the marker reloc.
But don't count them both ways.
Seen as "unresolvable R_PPC_REL24 relocation against symbol
`__tls_get_addr_opt'" (and other branch relocs).
* elf32-ppc.c (ppc_elf_tls_optimize): Don't process R_PPC_TLSLD
with non-local symbol. Don't double count __tls_get_addr calls
with marker relocs.
* elf64-ppc.c (ppc64_elf_tls_optimize): Likewise.
Alan Modra [Thu, 3 Oct 2019 23:18:41 +0000 (08:48 +0930)]
PowerPC PIC vs. DLL TLS issues
1) GOT entries generated for any of the GOT TLS relocations don't need
dynamic relocations for locally defined symbols in PIEs. In the case
of a tls_index doubleword, the dtpmod entry is known to be 1, and the
dtprel entry is also known at link time and relative. Similarly,
dtprel and tprel words are known at link time and relative. (GOT
entries for other than TLS symbols are not relative and thus need
dynamic relocations in PIEs.)
2) Local dynamic TLS code is really only meant for accesses local to
the current binary. There was a cheapskate test for this before using
the common tlsld_got slot, but the test wasn't exactly correct and
might confuse anyone looking at the code. The proper test,
SYMBOL_REFERENCES_LOCAL isn't so expensive that it should be avoided.
3) The same cheap test for local syms when optimising TLS sequences
should be SYMBOL_REFERENCES_LOCAL too.
bfd/
* elf64-ppc.c (ppc64_elf_check_relocs): Move initialisation of vars.
(ppc64_elf_tls_optimize): Correct is_local condition.
(allocate_got): Don't reserve dynamic relocations for any of the
tls got relocs in PIEs when the symbol is local.
(allocate_dynrelocs): Correct validity test for local sym using
tlsld_got slot.
(ppc64_elf_size_dynamic_sections): Don't reserve dynamic relocations
for any of the tls got relocs in PIEs.
(ppc64_elf_layout_multitoc): Likewise.
(ppc64_elf_relocate_section): Correct validity test for local sym
using tlsld_got slot. Don't emit dynamic relocations for any of
the tls got relocs in PIEs when the symbol is local.
* elf32-ppc.c (ppc_elf_tls_optimize): Correct is_local condition.
(got_relocs_needed): Delete.
(allocate_dynrelocs): Correct validity test for local sym using
tlsld_got slot. Don't reserve dynamic relocations for any of the
tls got relocs in PIEs when the symbol is local.
(ppc_elf_size_dynamic_sections): Don't reserve dynamic relocations
for any of the tls got relocs in PIEs.
(ppc_elf_relocate_section): Correct validity test for local sym
using tlsld_got slot. Don't emit dynamic relocations for any of
the tls got relocs in PIEs when the symbol is local.
ld/
* testsuite/ld-powerpc/tlsso.d: Adjust to suit tlsld_got usage change.
* testsuite/ld-powerpc/tlsso.g: Likewise.
* testsuite/ld-powerpc/tlsso.r: Likewise.
* testsuite/ld-powerpc/tlsso32.d: Likewise.
* testsuite/ld-powerpc/tlsso32.g: Likewise.
* testsuite/ld-powerpc/tlsso32.r: Likewise.
Jan Beulich [Fri, 20 Sep 2019 08:18:15 +0000 (10:18 +0200)]
x86-64: fix handling of PUSH/POP of segment register
Commit 21df382b91 ("x86: fold SReg{2,3}") went too far: Folding 64-bit
PUSH/POP templates into non-64-bit ones isn't correct, due to the
different operand widths, and hence suffixes permitted. Restore the
separate templates.
Add tests of PUSH/POP with q suffix and %fs/%gs operands to the
testsuite. While doing so also add PUSHF/POPF ones _without_ suffix.
Nick Clifton [Wed, 2 Oct 2019 10:57:16 +0000 (11:57 +0100)]
Change objcopy's --set-section-alignment option so that it takes a byte alignment value rather than a power of two alignment value.
PR 24942
* objcopy.c (copy_usage): Update description of
--set-section-alignment.
(copy_main): Interpret numeric argument of --set-section-alignment
as a byte alignment, not a power of two alignment.
* doc/binutils.texi: Update description of
--set-section-alignment.
* testsuite/binutils-all/set-section-alignment.d: New test.
* testsuite/binutils-all/objcopy.exp: Run the new test.
Alan Modra [Sat, 21 Sep 2019 08:43:52 +0000 (18:13 +0930)]
Work around gcc10 FAIL: S-records with constructors
gcc10 on x86_64 and powerpc64le recognises that the loop in
Foo::operator= can be turned into a call to memmove, which then
results in an undefined symbol when linking. Avoid that by making the
loop smaller.
* testsuite/ld-srec/sr3.cc (FOO_MSG_LEN): Set to 4.