Alan Modra [Thu, 21 Oct 2021 08:48:34 +0000 (19:18 +1030)]
-Waddress warning in ldelf.c
ldelf.c: In function 'ldelf_after_open':
ldelf.c:1049:43: warning: the comparison will always evaluate as 'true' for the address of 'elf_header' will never be NULL [-Waddress]
1049 | && elf_tdata (abfd)->elf_header != NULL
| ^~
In file included from ldelf.c:37:
../bfd/elf-bfd.h:1957:21: note: 'elf_header' declared here
1957 | Elf_Internal_Ehdr elf_header[1]; /* Actual data, but ref like ptr */
H.J. Lu [Mon, 25 Oct 2021 15:42:24 +0000 (08:42 -0700)]
gold: Place .note.gnu.property section before other note sections
Place the .note.gnu.property section before all other note sections to
avoid being placed between other note sections with different alignments.
PR gold/28494
* layout.cc (Layout::create_note): Set order to ORDER_PROPERTY_NOTE
for the .note.gnu.property section.
* layout.h (Output_section_order): Add ORDER_PROPERTY_NOTE.
Alan Modra [Tue, 2 Nov 2021 08:31:06 +0000 (19:01 +1030)]
PR28523, ld.bfd created undefined symbols on ppc64
This patch removes any fake (linker created) function descriptor
symbol if its code entry symbol isn't dynamic, to ensure bogus dynamic
symbols are not created. The change to func_desc_adjust requires that
it be run only once, which means ppc64_elf_tls_setup can't call it for
just a few selected symbols.
PR 28523
* elf64-ppc.c (func_desc_adjust): If a function entry sym is
not dynamic and has no plt entry, hide any associated fake
function descriptor symbol.
(ppc64_elf_edit): Move func_desc_adjust iteration over syms to..
(ppc64_elf_tls_setup): ..here.
Alan Modra [Tue, 19 Oct 2021 22:42:48 +0000 (09:12 +1030)]
Re: PR27625, powerpc64 gold __tls_get_addr calls
My previous PR27625 patch had a problem or two. For one, the error
"__tls_get_addr call lacks marker reloc" on processing some calls
before hitting a call without markers typically isn't seen. Instead a
gold assertion fails. Either way it would be a hard error, which
triggers on a file contained in libphobos.a when running the gcc
testsuite. A warning isn't even appropriate since the call involved
is one built by hand without any of the arg setup relocations that
might result in linker optimisation.
So this patch reverts most of commit 0af4fcc25dd5, instead entirely
ignoring the problem of mis-optimising old-style __tls_get_addr calls
without marker relocs. We can't handle them gracefully without
another pass over relocations before decisions are made about GOT
entries in Scan::global or Scan::local. That seems too costly, just
to link object files from 2009. What's more, there doesn't seem to be
any way to allow the libphobos explicit __tls_get_addr call, but not
old TLS sequences without marker relocs. Examining instructions
before the __tls_get_addr call is out of the question: program flow
might reach the call via a branch. Putting an R_PPC64_TLSGD marker
with zero sym on the call might be a solution, but current linkers
will then merrily optimise away the call!
PR gold/27625
* powerpc.cc (Powerpc_relobj): Delete no_tls_marker_, tls_marker_,
and tls_opt_error_ variables and accessors. Remove all uses.
Alan Modra [Thu, 14 Oct 2021 06:31:06 +0000 (17:01 +1030)]
[GOLD] Re: PowerPC64: Don't pretend to support multi-toc
We can't get at section->address() until everything is laid out, so
trying to generalise the offset calculation rather than using a value
of 0x8000 (the old object->toc_base_offset()) was bound to fail.
got->g_o_t() is a little better than a hard-coded 0x8000.
* powerpc.cc (Target_powerpc::Scan::local, global): Don't use
toc_pointer() here.
Alan Modra [Fri, 8 Oct 2021 23:33:21 +0000 (10:03 +1030)]
[GOLD] Two GOT sections for PowerPC64
Split .got into two piece, one with the header and entries for small
model got entries, the other with entries for medium/large model got
entries. The idea is to better support mixed pcrel/non-pcrel code
where non-pcrel small-model .toc entries need to be within 32k of the
toc pointer.
* target.h (Target::tls_offset_for_local): Add got param.
(Target::tls_offset_for_global): Likewise.
(Target::do_tls_offset_for_local, do_tls_offset_for_global): Likewise.
* output.h (Output_data_got::Got_entry::write): Add got param.
* output.cc (Output_data_got::Got_entry::write): Likewise, pass to
tls_offset_for_local/global calls.
(Output_data_got::do_write): Adjust to suit.
* s390.cc (Target_s390::do_tls_offset_for_local): Likewise.
(Target_s390::do_tls_offset_for_global): Likewise.
* powerpc.cc (enum Got_type): Extend with small types, move from
class Target_powerpc.
(Target_powerpc::biggot_): New.
(Traget_powerpc::do_tls_offset_for_local, do_tls_offset_for_global,
got_size, got_section, got_base_offset): Handle biggot_.
(Target_powerpc::do_define_standard_symbols): Adjust.
(Target_powerpc::make_plt_section, do_finalize_sections): Likewise.
(Output_data_got_powerpc::Output_data_got_powerpc): Only make
64-bit header for small got section.
(Output_data_got_powerpc::g_o_t): Only return a result for small
got section.
(Output_data_got_powerpc::write): Only write small got section
header.
(Target_powerpc::Scan::local, global): Select small/big Got_type
and section to suit reloc.
(Target_powerpc::Relocate::relocate): Similarly.
(Sort_toc_sections): Rewrite.
Alan Modra [Tue, 12 Oct 2021 09:15:13 +0000 (19:45 +1030)]
[GOLD] PowerPC64: Don't pretend to support multi-toc
Code in powerpc.cc is pretending to support a per-object toc pointer
value, but powerpc gold has no real support for multi-toc. This patch
removes the pretense, tidying quite a lot in preparation for a
followup patch. If multi-toc is ever to be supported, don't revert
this patch but start by adding object parameter to toc_pointer() and
an object to Branch_stub_key.
* powerpc.cc (Powerpc_relobj::toc_base_offset): Delete.
(Target_powerpc::toc_pointer): New function. Use throughout.
(Target_powerpc::got_base_offset): New function. Use throughout..
(Output_data_got_powerpc::got_base_offset): ..in place of
this. Delete.
(Output_data_got_powerpc::Output_data_got_powerpc): Init
header_index_ to -1u for 64-bit, and make header here.
(Output_data_got_powerpc::set_final_data_size, reserve_ent): Don't
make 64-bit header here.
(Output_data_got_powerpc::g_o_t): Return toc pointer offset in
section for 64-bit. Use throughout.
(Stub_table): Remove toc_base_off_ from Branch_stub_key, and
object param on add_long_branch_entry and find_long_branch_entry.
Adjust all uses.