Move UNDEFWEAK_NO_DYNAMIC_RELOC to elf-bfd.h so that it can be used by
other ELF linker backends.
* elf32-ppc.c (UNDEFWEAK_NO_DYNAMIC_RELOC): Moved to ...
* elf-bfd.h (UNDEFWEAK_NO_DYNAMIC_RELOC): Here.
* elf64-ppc.c (UNDEFWEAK_NO_DYNAMIC_RELOC): Removed.
Fix commit 70a38d42c5 ("New entry points for writing Linux NT_PRPSINFO
notes."), <https://sourceware.org/ml/binutils/2013-02/msg00023.html>,
and commit b3ac9c7756 ("Put more info in NT_PRPSINFO Linux notes"),
<https://sourceware.org/ml/binutils/2013-02/msg00024.html>, and handle
both variants of the 32-bit Linux core PRPSINFO note across all targets.
The 32-bit Linux core PRPSINFO note matches the 32-bit kernel structure,
defined as follows:
(gdb) ptype struct elf_prpsinfo
type = struct elf_prpsinfo {
char pr_state;
char pr_sname;
char pr_zomb;
char pr_nice;
unsigned long pr_flag;
__kernel_uid_t pr_uid;
__kernel_gid_t pr_gid;
pid_t pr_pid;
pid_t pr_ppid;
pid_t pr_pgrp;
pid_t pr_sid;
char pr_fname[16];
char pr_psargs[80];
}
(gdb)
where the individual data types of most members are the same across all
32-bit Linux ports, with the exception of `__kernel_uid_t' and
`__kernel_gid_t'. These are defined in <asm-generic/posix_types.h> as
32-bit `unsigned int' by default, however overridden as 16-bit `unsigned
short' in port-specific <asm/posix_types.h> for a few targets, mostly
earlier ports of Linux, specifically: ARM, CRIS, FR-V, M32R, m68k,
MN10300/AM33, s390, SuperH, SPARC and i386.
The default is the same as the PowerPC variant already handled, as from
the commits referred. Make the special PowerPC case generic then,
removing the GDB part, and provide a backend flag to switch between the
two cases possible, with the 32-bit one being the default and the 16-bit
one explicitly selected. Set the flag in the target backends affected.
bfd/
* elf-bfd.h (elf_backend_data): Add `linux_prpsinfo32_ugid16'
member.
(elfcore_write_ppc_linux_prpsinfo32): Remove prototype.
* elf32-ppc.c (elfcore_write_ppc_linux_prpsinfo32): Remove.
(elf_external_ppc_linux_prpsinfo32)
(swap_ppc_linux_prpsinfo32_out): Move to...
* elf-linux-core.h (elf_external_linux_prpsinfo32_ugid32)
(swap_linux_prpsinfo32_ugid32_out): ... these.
(elf_external_linux_prpsinfo32): Rename to...
(elf_external_linux_prpsinfo32_ugid16): ... this.
(swap_linux_prpsinfo32_out): Rename to...
(swap_linux_prpsinfo32_ugid16_out): ... this.
* elfxx-target.h [!elf_backend_linux_prpsinfo32_ugid16]
(elf_backend_linux_prpsinfo32_ugid16): Define.
(elfNN_bed): Initialize `linux_prpsinfo32_ugid16' member.
* elf.c (elfcore_write_linux_prpsinfo32): Handle both variants
of the 32-bit Linux core PRPSINFO note.
* elf32-am33lin.c (elf_backend_linux_prpsinfo32_ugid16): Define.
* elf32-arm.c (elf_backend_linux_prpsinfo32_ugid16): Define.
* elf32-cris.c (elf_backend_linux_prpsinfo32_ugid16): Define.
* elf32-frv.c (elf_backend_linux_prpsinfo32_ugid16): Define.
* elf32-i386.c (elf_backend_linux_prpsinfo32_ugid16): Define.
* elf32-m32r.c (elf_backend_linux_prpsinfo32_ugid16): Define.
* elf32-m68k.c (elf_backend_linux_prpsinfo32_ugid16): Define.
* elf32-s390.c (elf_backend_linux_prpsinfo32_ugid16): Define.
* elf32-sh.c (elf_backend_linux_prpsinfo32_ugid16): Define.
* elf32-sparc.c (elf_backend_linux_prpsinfo32_ugid16): Define.
gdb/
* ppc-linux-tdep.c (ppc_linux_init_abi): Remove call to
`set_gdbarch_elfcore_write_linux_prpsinfo'.
Dump dynamic relocation info to the map file when generating dynamic
relocation in read-only section relocations if -Map is used.
* elf32-ppc.c (readonly_dynrelocs): Add a link_info argument.
Dump dynamic relocation in read-only section with minfo if
needed.
(ppc_elf_adjust_dynamic_symbol): Pass NULL to readonly_dynrelocs.
(maybe_set_textrel): Likewise.
(ppc_elf_size_dynamic_sections): Dump dynamic relocation in
read-only section with minfo.
In the TLS GD/LD to LE optimization, ld replaces a sequence like
addi 3,2,x@got@tlsgd R_PPC64_GOT_TLSGD16 x
bl __tls_get_addr(x@tlsgd) R_PPC64_TLSGD x
R_PPC64_REL24 __tls_get_addr
nop
with
addis 3,13,x@tprel@ha R_PPC64_TPREL16_HA x
addi 3,3,x@tprel@l R_PPC64_TPREL16_LO x
nop
When the tprel offset is small, this can be further optimized to
nop
addi 3,13,x@tprel
nop
bfd/
* elf64-ppc.c (struct ppc_link_hash_table): Add do_tls_opt.
(ppc64_elf_tls_optimize): Set it.
(ppc64_elf_relocate_section): Nop addis on TPREL16_HA, and convert
insn on TPREL16_LO and TPREL16_LO_DS relocs to use r13 when
addis would add zero.
* elf32-ppc.c (struct ppc_elf_link_hash_table): Add do_tls_opt.
(ppc_elf_tls_optimize): Set it.
(ppc_elf_relocate_section): Nop addis on TPREL16_HA, and convert
insn on TPREL16_LO relocs to use r2 when addis would add zero.
gold/
* powerpc.cc (Target_powerpc::Relocate::relocate): Nop addis on
TPREL16_HA, and convert insn on TPREL16_LO and TPREL16_LO_DS
relocs to use r2/r13 when addis would add zero.
ld/
* testsuite/ld-powerpc/tls.s: Add calls with tls markers.
* testsuite/ld-powerpc/tls32.s: Likewise.
* testsuite/ld-powerpc/powerpc.exp: Run tls marker tests.
* testsuite/ld-powerpc/tls.d: Adjust for TPREL16_HA/LO optimization.
* testsuite/ld-powerpc/tlsexe.d: Likewise.
* testsuite/ld-powerpc/tlsexetoc.d: Likewise.
* testsuite/ld-powerpc/tlsld.d: Likewise.
* testsuite/ld-powerpc/tlsmark.d: Likewise.
* testsuite/ld-powerpc/tlsopt4.d: Likewise.
* testsuite/ld-powerpc/tlstoc.d: Likewise.
Tidy how these are handled in PIEs.
* elf32-ppc.c (must_be_dyn_reloc): Use bfd_link_dll. Comment.
(ppc_elf_check_relocs): Only set DF_STATIC_TLS in shared libs.
(ppc_elf_relocate_section): Comment fix.
* elf64-ppc.c (must_be_dyn_reloc): Use bfd_link_dll. Comment.
(ppc64_elf_check_relocs): Only set DF_STATIC_TLS in shared libs.
Support dynamic relocs for TPREL16 when non-pic too.
(dec_dynrel_count): Adjust TPREL16 handling as per check_relocs.
(ppc64_elf_relocate_section): Support dynamic relocs for TPREL16
when non-pic too.
..if they have dynamic relocs. An undefined symbol in a PIC object
that finds no definition ought to become dynamic in order to support
--allow-shlib-undefined, but there is nothing in the generic ELF
linker code to do this if the reference isn't via the GOT or PLT. (An
initialized function pointer is an example.) So it falls to backend
code to ensure the symbol is made dynamic.
PR 21988
* elf64-ppc.c (ensure_undef_dynamic): Rename from
ensure_undefweak_dynamic. Handle undefined too.
* elf32-ppc.c (ensure_undef_dynamic): Likewise.
* elf32-hppa.c (ensure_undef_dynamic): Likewise.
(allocate_dynrelocs): Discard undefined non-default visibility
relocs first. Make undefined syms dynamic. Tidy goto.
My 2017-01-24 patch (commit f0158f44) wrongly applied an optimization
of GOT entries for the __tls_get_addr_opt stub, to shared libraries.
When the TLS segment layout is known, as it is for the executable and
shared libraries loaded at initial program start, powerpc supports a
__tls_get_addr optimization. On the first call to __tls_get_addr for
a given __tls_index GOT entry, the DTPMOD word is set to zero and the
DTPREL word to the thread pointer offset to the thread variable. This
allows the __tls_get_addr_opt stub to return that value immediately
without making a call into glibc for any subsequent __tls_get_addr
calls using that __tls_index GOT entry.
That's all fine, but I thought I'd be clever and when the thread
variable is local, set up the GOT entry as if __tls_get_addr had
already been called. Which is good only for the executable, since ld
cannot know the TLS layout for shared libraries.
Of course, if this only applies to executables there isn't much point
to the optimization. Normally, GD and LD code in an executable will
be converted to IE or LE, losing the __tls_get_addr call. So the only
time it will trigger is with --no-tls-optimize. Thus, revert all
support.
* elf64-ppc.c (ppc64_elf_relocate_section): Don't optimize
__tls_index GOT entries when using __tls_get_addr_opt stub.
* elf32-ppc.c (ppc_elf_relocate_section): Likewise.
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.
-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.
If you should somehow link non-pic objects into a PIE or shared
library, resulting in an object with DT_TEXTREL (text relocations)
set, and your executable or shared library also contains GNU indirect
functions, then you're in trouble. To apply dynamic relocations
ld.so will make the text segment writable. On most systems this will
make the text segment non-executable, which will then result in a
segfault when ld.so tries to run ifunc resolvers when applying
relocations against ifuncs.
This patch teaches PowerPC ld to detect the situation, and warn.
* elf64-ppc.c (struct ppc_link_hash_table): Add
local_ifunc_resolver and maybe_local_ifunc_resolver.
(ppc_build_one_stub): Set flags on emitting dynamic
relocation to ifunc.
(ppc64_elf_relocate_section): Likewise.
(ppc64_elf_finish_dynamic_symbol): Likewise.
(ppc64_elf_finish_dynamic_sections): Error on DT_TEXTREL with
local dynamic relocs to ifuncs.
* elf32-ppc.c (struct ppc_elf_link_hash_table): Add
local_ifunc_resolver and maybe_local_ifunc_resolver.
(ppc_elf_relocate_section): Set flag on emitting dynamic
relocation to ifuncs.
(ppc_elf_finish_dynamic_symbol): Likewise.
(ppc_elf_finish_dynamic_sections): Error on DT_TEXTREL with local
dynamic relocs to ifuncs.
This came up because I was looking at ld/tmpdir/addpcis.o and noticed
the odd addends on REL16DX_HA. They ought to both be -4. The error
crept in due REL16DX_HA howto being pc-relative (as indeed it should
be), and code at gas/write.c:1001 after this comment
/* Make it pc-relative. If the back-end code has not
selected a pc-relative reloc, cancel the adjustment
we do later on all pc-relative relocs. */
*not* cancelling the pc-relative adjustment. So I've made a dummy
non-relative split reloc so that the generic code handles this, rather
than attempting to add hacks later in md_apply_fix which would not be
very robust. Having the new internal reloc also makes it easy to
support
addpcis rx,sym@ha
as an equivalent to
addpcis rx,(sym-0f)@ha
0:
The patch also fixes overflow checking, which must test whether the
addi will overflow too since @l relocs don't have any overflow check.
Lastly, since I was poking at md_apply_fix, I arranged to have the
generic gas/write.c code emit errors for subtraction expressions where
we lack reloc support.
include/
* elf/ppc64.h (R_PPC64_16DX_HA): New. Expand fake reloc comment.
* elf/ppc.h (R_PPC_16DX_HA): Likewise.
bfd/
* reloc.c (BFD_RELOC_PPC_16DX_HA): New.
* elf64-ppc.c (ppc64_elf_howto_raw <R_PPC64_16DX_HA>): New howto.
(ppc64_elf_reloc_type_lookup): Translate new bfd reloc.
(ppc64_elf_ha_reloc): Correct overflow test on REL16DX_HA.
(ppc64_elf_relocate_section): Likewise.
* elf32-ppc.c (ppc_elf_howto_raw <R_PPC_16DX_HA>): New howto.
(ppc_elf_reloc_type_lookup): Translate new bfd reloc.
(ppc_elf_check_relocs): Handle R_PPC_16DX_HA to pacify gcc.
* libbfd.h: Regenerate.
* bfd-in2.h: Regenerate.
gas/
* config/tc-ppc.c (md_assemble): Use BFD_RELOC_PPC_16DX_HA for addpcis.
(md_apply_fix): Remove fx_subsy check. Move code converting to
pcrel reloc earlier and handle BFD_RELOC_PPC_16DX_HA. Remove code
emiiting errors on seeing fx_pcrel set on unexpected relocs, as
that is done now by the generic code via..
* config/tc-ppc.h (TC_FORCE_RELOCATION_SUB_LOCAL): ..this. Define.
(TC_VALIDATE_FIX_SUB): Define.
ld/
* testsuite/ld-powerpc/addpcis.d: Define ext1 and ext2 at
limits of addpcis range.
I'd made this dynamic section read-only so a flag test distinguished
it from .dynbss, but like any other .data.rel.ro section it really
should be marked read-write. (It is read-only after relocation, not
before.) When using the standard linker scripts this usually doesn't
matter since the output section is among other read-write sections and
not page aligned. However, it might matter in the extraordinary case
of the dynamic section being the only .data.rel.ro section with the
output section just happening to be page aligned and a multiple of a
page in size. In that case the output section would be read-only, and
live it its own read-only PT_LOAD segment, which is incorrect.
* elflink.c (_bfd_elf_create_dynamic_sections): Don't make
dynamic .data.rel.ro read-only.
* elf32-arm.c (elf32_arm_finish_dynamic_symbol): Compare section
rather than section flags when deciding where copy reloc goes.
* elf32-cris.c (elf_cris_finish_dynamic_symbol): Likewise.
* elf32-hppa.c (elf32_hppa_finish_dynamic_symbol): Likewise.
* elf32-i386.c (elf_i386_finish_dynamic_symbol): Likewise.
* elf32-metag.c (elf_metag_finish_dynamic_symbol): Likewise.
* elf32-microblaze.c (microblaze_elf_finish_dynamic_symbol): Likewise.
* elf32-nios2.c (nios2_elf32_finish_dynamic_symbol): Likewise.
* elf32-or1k.c (or1k_elf_finish_dynamic_symbol): Likewise.
* elf32-ppc.c (ppc_elf_finish_dynamic_symbol): Likewise.
* elf32-s390.c (elf_s390_finish_dynamic_symbol): Likewise.
* elf32-tic6x.c (elf32_tic6x_finish_dynamic_symbol): Likewise.
* elf32-tilepro.c (tilepro_elf_finish_dynamic_symbol): Likewise.
* elf64-ppc.c (ppc64_elf_finish_dynamic_symbol): Likewise.
* elf64-s390.c (elf_s390_finish_dynamic_symbol): Likewise.
* elf64-x86-64.c (elf_x86_64_finish_dynamic_symbol): Likewise.
* elfnn-aarch64.c (elfNN_aarch64_finish_dynamic_symbol): Likewise.
* elfnn-riscv.c (riscv_elf_finish_dynamic_symbol): Likewise.
* elfxx-mips.c (_bfd_mips_vxworks_finish_dynamic_symbol): Likewise.
* elfxx-sparc.c (_bfd_sparc_elf_finish_dynamic_symbol): Likewise.
* elfxx-tilegx.c (tilegx_elf_finish_dynamic_symbol): Likewise.
PR 20744
bfd/
* elf32-ppc.c (ppc_elf_howto_raw): Correct dst_mask on all VLE
16D relocations.
(ppc_elf_vle_split16): Correct field mask and shift for 16D relocs.
(ppc_elf_relocate_section): Correct calculation for VLE SDAREL
relocs.
ld/
* testsuite/ld-powerpc/vle-reloc-2.s: Use r6 for last insn of
each group.
* testsuite/ld-powerpc/vle-reloc-2.d: Update for above change
and sdarel reloc fix.
Remove an inconsistency in BFD linker error messages across the PowerPC
backends, where in the presence of line information the `%P: %H:' format
sequence makes the first error message produced for any given function
different from subsequent ones.
Taking the `ld/testsuite/ld-powerpc/tocopt7.s' test case source as an
example and the `powerpc-linux' target we have:
$ as -gdwarf2 -o tocopt.o -a64 tocopt.s
$ ld -o tocopt -melf64ppc tocopt.o
ld: tocopt.o: In function `_start':
tocopt.s:35:(.text+0x14): toc optimization is not supported for 0x3fa00000 instruction.
ld: tocopt.s:49:(.text+0x34): toc optimization is not supported for 0x3fa00000 instruction.
$
where the first error message does not have the source file name
prefixed with the linker program executable's name, i.e. `ld:', whereas
the second error message does, as would any subsequent.
This is because with a multiple-line error message such as `%H' produces
`%P' only prints the program executable's name on the first line and not
any later ones. Also the PowerPC backend is the only part of BFD which
uses `%P' along with one of the clever `%C', `%D', `%G', `%H' format
specifiers. And last but not least this breaks a GNU Coding Standard's
requirement that error messages from compilers should look like this:
source-file-name:lineno: message
also quoted in `vfinfo' code handling these specifiers.
Convert `%P: %H:' to `%H:' in error messages across the PowerPC backends
then, yielding:
$ as -gdwarf2 -o tocopt.o -a64 tocopt.s
$ ld -o tocopt -melf64ppc tocopt.o
tocopt.o: In function `_start':
tocopt.s:35:(.text+0x14): toc optimization is not supported for 0x3fa00000 instruction.
tocopt.s:49:(.text+0x34): toc optimization is not supported for 0x3fa00000 instruction.
$
instead, making it consistent and matching the GNU Coding Standard's
requirement.
bfd/
* elf32-ppc.c (ppc_elf_check_relocs): Use `%H:' rather than
`%P: %H:' with `info->callbacks->einfo'.
(ppc_elf_relocate_section): Likewise.
* elf64-ppc.c (ppc64_elf_check_relocs): Likewise.
(ppc64_elf_edit_toc): Likewise.
(ppc64_elf_relocate_section): Likewise.
Complement commit 81ff47b3a5 ("PR ld/20828: Fix linker script symbols
wrongly forced local with section GC") and move the symbol sweep stage
of section GC from `elf_gc_sweep' to `bfd_elf_size_dynamic_sections',
avoiding the need to clear the `forced_local' marker, problematic for
targets that have special processing in their `elf_backend_hide_symbol'
handler. Set `mark' instead in `bfd_elf_record_link_assignment' and,
matching changes from commit 3bd43ebcb6 ("ld --gc-sections fail with
__tls_get_addr_opt"), also in PowerPC `__tls_get_addr_opt' handling
code, removing a:
FAIL: PR ld/20828 dynamic symbols with section GC (version script)
test suite failure with the `score-elf' target.
The rationale is it is enough if symbols are swept at the beginning of
`bfd_elf_size_dynamic_sections' as it is only in this function that the
size of the GOT, the dynamic symbol table and other dynamic sections is
determined, which will depend on the number of symbols making it to the
dynamic symbol table. It is also appropriate to do the sweep at this
point as it is already after any changes have been made to symbols with
`bfd_elf_record_link_assignment', and not possible any earlier as calls
to that function are only made just beforehand -- barring audit entry
processing -- via `gld${EMULATION_NAME}_find_statement_assignment'
invoked from `gld${EMULATION_NAME}_before_allocation' which is the ELF
handler for `ldemul_before_allocation'.
bfd/
PR ld/20828
* elflink.c (bfd_elf_record_link_assignment): Revert last
change and don't ever clear `forced_local'. Set `mark'
unconditionally.
(elf_gc_sweep_symbol_info, elf_gc_sweep_symbol): Reorder within
file.
(elf_gc_sweep): Move the call to `elf_gc_sweep_symbol'...
(bfd_elf_size_dynamic_sections): ... here.
* elf32-ppc.c (ppc_elf_tls_setup): Don't clear `forced_local'
and set `mark' instead in `__tls_get_addr_opt' processing.
* elf64-ppc.c (ppc64_elf_tls_setup): Likewise.
This patch fixes a number of issues with powerpc dynamic relocations.
1) Both ppc and ppc64 were emitting more dynamic symbols and
relocations than necessary, due to not supporting static linker
resolution of tls_index entries for __tls_get_addr_opt. This meant
that any @got@tlsgd or @got@tlsld reloc needed to make their symbols
dynamic and generate dptmod and dtprel relocs for the dynamic linker.
That would have been passable, but what happened was that practically
all @got relocations resulted in their symbols being made dynamic and
dynamic relocations emitted against the GOT entries. (Mostly visible
on ppc32 executables since ppc64 gcc really only uses @got style
relocs for TLS.)
2) The PowerOpen syntax was not supported with __tls_get_addr_opt.
DTPMOD/DTPREL relocs on tls_index TOC entries did not use the trick of
forcing dynamic symbols and relocations so those entries always
resulted in the full __tls_get_addr processing. gcc doesn't use the
PowerOpen syntax for TLS, and normally such code would be optimized to
TLS IE or LE so the impact of missing this support was minimal.
3) In an executable, relocations against GNU indirect functions always
used the value of their PLT stub. While this is correct, it is
better in some cases to use a dynamic relocation. An extra dynamic
relocation can mean that calls via function pointers need not bounce
through the PLT stub at runtime.
The patch also tidies the PLT handling code in ppc32
allocate_dynrelocs. Allocating PLT entries after other dynamic relocs
allows the PLT loop to omit special handling for undefined weak
symbols, and that in turn allows the loop to be simplified.
bfd/
* elf32-ppc.c (ppc_elf_adjust_dynamic_symbol): Merge two cases
where dynamic relocs are preferable. Allow ifunc too.
(ensure_undefweak_dynamic): New function.
(allocate_dynrelocs): Use it here. Move plt handling last and
don't make symbols dynamic, simplifying loop. Only make undef
weak symbols with GOT entries dynamic. Correct condition
for GOT relocs. Handle dynamic relocs on ifuncs. Correct
comments. Remove goto.
(ppc_elf_relocate_section): Correct test for using dynamic
symbol on GOT relocs. Rearrange test for emitting GOT relocs
to suit. Set up explicit tls_index entries and implicit GOT
tls_index entries resolvable at link time for
__tls_get_addr_opt. Simplify test to clear mem for prelink.
* elf64-ppc.c (allocate_got): Correct condition for GOT relocs.
(ensure_undefweak_dynamic): New function.
(allocate_dynrelocs): Use it here. Only make undef weak symbols
with GOT entries dynamic. Remove unnecessary test of
WILL_CALL_FINISH_DYNAMIC_SYMBOL in PLT handling.
(ppc64_elf_relocate_section): Correct test for using dynamic
symbol on GOT relocs. Rearrange test for emitting GOT relocs
to suit. Set up explicit tls_index entries and implicit GOT
tls_index entries resolvable at link time for __tls_get_addr_opt.
Simplify expression to clear mem for prelink.
ld/
* testsuite/ld-powerpc/tlsexe.r: Update for fewer dynamic relocs
and symbols.
* testsuite/ld-powerpc/tlsexe.d: Likewise.
* testsuite/ld-powerpc/tlsexe.g: Likewise.
A while ago HJ fixed PR ld/18720 with commit 6e33951ed, which, among
other things, modified _bfd_elf_link_hash_copy_indirect to not copy
ref_dynamic, ref_regular, ref_regular_nonweak, non_got_ref, needs_plt
and pointer_equality_needed when setting up an indirect non-versioned
symbol pointing to a non-default versioned symbol. I didn't notice at
the time, but the pr18720 testcase fails on hppa-linux with
"internal error, aborting at binutils-gdb-2.28/bfd/elf32-hppa.c:3933
in elf32_hppa_relocate_section".
Now hppa-linux creates entries in the plt even for local functions, if
they are referenced using plabel (function pointer) relocations. So
needs_plt is set for foo when processing pr18720a.o. When the aliases
in pr28720b.o are processed, we get an indirection from foo to
foo@FOO, but don't copy needs_plt. Since foo@FOO is the "real" symbol
that is used after that point, no plt entry is made for foo and we
bomb when relocating the plabel.
As shown by the hppa-linux scenario, needs_plt should be copied even
for non-default versioned symbols. I believe all of the others ought
to be copied too, with the exception of ref_dynamic. Not copying
ref_dynamic is right because if a shared lib references "foo" it
should not be satisfied by any non-default version "foo@FOO".
* elflink.c (_bfd_elf_link_hash_copy_indirect): Only omit
copying one flag, ref_dynamic, when versioned_hidden.
* elf64-ppc.c (ppc64_elf_copy_indirect_symbol): Likewise.
* elf32-hppa.c (elf32_hppa_copy_indirect_symbol): Use same
logic for copying weakdef flags. Copy plabel flag and merge
tls_type.
* elf32-i386.c (elf_i386_copy_indirect_symbol): Use same logic
for copying weakdef flags.
* elf32-ppc.c (ppc_elf_copy_indirect_symbol): Likewise.
* elf32-s390.c (elf_s390_copy_indirect_symbol): Likewise.
* elf32-sh.c (sh_elf_copy_indirect_symbol): Likewise.
* elf64-s390.c (elf_s390_copy_indirect_symbol): Likewise.
* elfnn-ia64.c (elfNN_ia64_hash_copy_indirect): Likewise.
* elf64-x86-64.c (elf_x86_64_copy_indirect_symbol): Likewise.
Simplify.
Variables defined in shared libraries are copied into an executable's
.bss section when code in the executable is non-PIC and thus would
require dynamic text relocations to access the variable directly in
the shared library. Recent x86 toolchains also copy variables into
the executable to gain a small speed improvement.
The problem is that if the variable was originally read-only, the copy
in .bss is writable, potentially opening a security hole. This patch
cures that problem by putting the copy in a section that becomes
read-only after ld.so relocation, provided -z relro is in force.
The patch also fixes a microblaze linker segfault on attempting to
use dynamic bss variables.
bfd/
PR ld/20995
* elf-bfd.h (struct elf_link_hash_table): Add sdynrelro and
sreldynrelro.
(struct elf_backend_data): Add want_dynrelro.
* elfxx-target.h (elf_backend_want_dynrelro): Define.
(elfNN_bed): Update initializer.
* elflink.c (_bfd_elf_create_dynamic_sections): Create
sdynrelro and sreldynrelro sections.
* elf32-arm.c (elf32_arm_adjust_dynamic_symbol): Place variables
copied into the executable from read-only sections into sdynrelro.
(elf32_arm_size_dynamic_sections): Handle sdynrelro.
(elf32_arm_finish_dynamic_symbol): Select sreldynrelro for
dynamic relocs in sdynrelro.
(elf_backend_want_dynrelro): Define.
* elf32-hppa.c (elf32_hppa_adjust_dynamic_symbol)
(elf32_hppa_size_dynamic_sections, elf32_hppa_finish_dynamic_symbol)
(elf_backend_want_dynrelro): As above.
* elf32-i386.c (elf_i386_adjust_dynamic_symbol)
(elf_i386_size_dynamic_sections, elf_i386_finish_dynamic_symbol)
(elf_backend_want_dynrelro): As above.
* elf32-metag.c (elf_metag_adjust_dynamic_symbol)
(elf_metag_size_dynamic_sections, elf_metag_finish_dynamic_symbol)
(elf_backend_want_dynrelro): As above.
* elf32-microblaze.c (microblaze_elf_adjust_dynamic_symbol)
(microblaze_elf_size_dynamic_sections)
(microblaze_elf_finish_dynamic_symbol)
(elf_backend_want_dynrelro): As above.
* elf32-nios2.c (nios2_elf32_finish_dynamic_symbol)
(nios2_elf32_adjust_dynamic_symbol)
(nios2_elf32_size_dynamic_sections)
(elf_backend_want_dynrelro): As above.
* elf32-or1k.c (or1k_elf_finish_dynamic_symbol)
(or1k_elf_adjust_dynamic_symbol, or1k_elf_size_dynamic_sections)
(elf_backend_want_dynrelro): As above.
* elf32-ppc.c (ppc_elf_adjust_dynamic_symbol)
(ppc_elf_size_dynamic_sections, ppc_elf_finish_dynamic_symbol)
(elf_backend_want_dynrelro): As above.
* elf32-s390.c (elf_s390_adjust_dynamic_symbol)
(elf_s390_size_dynamic_sections, elf_s390_finish_dynamic_symbol)
(elf_backend_want_dynrelro): As above.
* elf32-tic6x.c (elf32_tic6x_adjust_dynamic_symbol)
(elf32_tic6x_size_dynamic_sections)
(elf32_tic6x_finish_dynamic_symbol)
(elf_backend_want_dynrelro): As above.
* elf32-tilepro.c (tilepro_elf_adjust_dynamic_symbol)
(tilepro_elf_size_dynamic_sections)
(tilepro_elf_finish_dynamic_symbol)
(elf_backend_want_dynrelro): As above.
* elf64-ppc.c (ppc64_elf_adjust_dynamic_symbol)
(ppc64_elf_size_dynamic_sections, ppc64_elf_finish_dynamic_symbol)
(elf_backend_want_dynrelro): As above.
* elf64-s390.c (elf_s390_adjust_dynamic_symbol)
(elf_s390_size_dynamic_sections, elf_s390_finish_dynamic_symbol)
(elf_backend_want_dynrelro): As above.
* elf64-x86-64.c (elf_x86_64_adjust_dynamic_symbol)
(elf_x86_64_size_dynamic_sections)
(elf_x86_64_finish_dynamic_symbol)
(elf_backend_want_dynrelro): As above.
* elfnn-aarch64.c (elfNN_aarch64_adjust_dynamic_symbol)
(elfNN_aarch64_size_dynamic_sections)
(elfNN_aarch64_finish_dynamic_symbol)
(elf_backend_want_dynrelro): As above.
* elfnn-riscv.c (riscv_elf_adjust_dynamic_symbol)
(riscv_elf_size_dynamic_sections, riscv_elf_finish_dynamic_symbol)
(elf_backend_want_dynrelro): As above.
* elfxx-mips.c (_bfd_mips_elf_adjust_dynamic_symbol)
(_bfd_mips_elf_size_dynamic_sections)
(_bfd_mips_vxworks_finish_dynamic_symbol): As above.
* elfxx-sparc.c (_bfd_sparc_elf_adjust_dynamic_symbol)
(_bfd_sparc_elf_size_dynamic_sections)
(_bfd_sparc_elf_finish_dynamic_symbol): As above.
* elfxx-tilegx.c (tilegx_elf_adjust_dynamic_symbol)
(tilegx_elf_size_dynamic_sections)
(tilegx_elf_finish_dynamic_symbol): As above.
* elf32-mips.c (elf_backend_want_dynrelro): Define.
* elf64-mips.c (elf_backend_want_dynrelro): Define.
* elf32-sparc.c (elf_backend_want_dynrelro): Define.
* elf64-sparc.c (elf_backend_want_dynrelro): Define.
* elf32-tilegx.c (elf_backend_want_dynrelro): Define.
* elf64-tilegx.c (elf_backend_want_dynrelro): Define.
* elf32-microblaze.c (microblaze_elf_adjust_dynamic_symbol): Tidy.
(microblaze_elf_size_dynamic_sections): Handle sdynbss.
* elf32-nios2.c (nios2_elf32_size_dynamic_sections): Make use
of linker shortcuts to dynamic sections rather than comparing
names. Correctly set "got" flag.
ld/
PR ld/20995
* testsuite/ld-arm/farcall-mixed-app-v5.d: Update to suit changed
stub hash table traversal caused by section id increment. Accept
the previous output too.
* testsuite/ld-arm/farcall-mixed-app.d: Likewise.
* testsuite/ld-arm/farcall-mixed-lib-v4t.d: Likewise.
* testsuite/ld-arm/farcall-mixed-lib.d: Likewise.
* testsuite/ld-elf/pr20995a.s, * testsuite/ld-elf/pr20995b.s,
* testsuite/ld-elf/pr20995.r: New test.
* testsuite/ld-elf/elf.exp: Run it.
It makes just a little more sense to use input_bfd when retrieving
insns for relocation, since the relocations match the endianness of
the input bfd.
* elf32-ppc.c (ppc64_elf_relocate_section): Calculate d_offset for
input_bfd. Replace occurrences of output_bfd as bfd_get_32 and
bfd_put_32 param with input_bfd.
* elf32-ppc.c (ppc_elf_relocate_section): Likewise. Also
ppc_elf_vle_split16 param.
(ppc_elf_vle_split16): Rename output_bfd param to input_bfd.
This patch extends Tag_GNU_Power_ABI_FP to cover long double ABIs,
makes the assembler warn about undefined tag values, and removes
similar warnings from the linker. I think it is better to not
warn in the linker about undefined tag values as future extensions to
the tags then won't result in likely bogus warnings. This is
consistent with the fact that an older linker won't warn on an
entirely new tag.
include/
* elf/ppc.h (Tag_GNU_Power_ABI_FP): Comment.
bfd/
* elf-bfd.h (_bfd_elf_ppc_merge_fp_attributes): Declare.
* elf32-ppc.c (_bfd_elf_ppc_merge_fp_attributes): New function.
(ppc_elf_merge_obj_attributes): Use it. Don't copy first file
attributes, merge them. Don't warn about undefined tag bits,
or copy unknown values to output.
* elf64-ppc.c (ppc64_elf_merge_private_bfd_data): Call
_bfd_elf_ppc_merge_fp_attributes.
binutils/
* readelf.c (display_power_gnu_attribute): Catch truncated section
for all powerpc attributes. Display long double ABI. Don't
capitalize words, except for names. Show known bits of tag values
when some unknown bits are present. Whitespace fixes.
gas/
* config/tc-ppc.c (ppc_elf_gnu_attribute): New function.
(md_pseudo_table <ELF>): Handle "gnu_attribute".
ld/
* testsuite/ld-powerpc/attr-gnu-4-4.s: Delete.
* testsuite/ld-powerpc/attr-gnu-4-14.d: Delete.
* testsuite/ld-powerpc/attr-gnu-4-24.d: Delete.
* testsuite/ld-powerpc/attr-gnu-4-34.d: Delete.
* testsuite/ld-powerpc/attr-gnu-4-41.d: Delete.
* testsuite/ld-powerpc/attr-gnu-4-32.d: Adjust expected warning.
* testsuite/ld-powerpc/attr-gnu-8-23.d: Likewise.
* testsuite/ld-powerpc/attr-gnu-4-01.d: Adjust expected output.
* testsuite/ld-powerpc/attr-gnu-4-02.d: Likewise.
* testsuite/ld-powerpc/attr-gnu-4-03.d: Likewise.
* testsuite/ld-powerpc/attr-gnu-4-10.d: Likewise.
* testsuite/ld-powerpc/attr-gnu-4-11.d: Likewise.
* testsuite/ld-powerpc/attr-gnu-4-20.d: Likewise.
* testsuite/ld-powerpc/attr-gnu-4-22.d: Likewise.
* testsuite/ld-powerpc/attr-gnu-4-33.d: Likewise.
* testsuite/ld-powerpc/attr-gnu-8-11.d: Likewise.
* testsuite/ld-powerpc/powerpc.exp: Don't run deleted tests.
ELF section sh_flags SHF_PPC_VLE was being set based on arch/mach,
which meant all code sections in an object file has the flag or all
lacked it. We can do better than that. Only those code sections
where VLE is enabled ought to have the flag, allowing an object file
to contain both VLE and non-VLE code.
Also, ELF header p_flags PF_PPC_VLE wasn't being set, and segments
were being split unnecessarily.
bfd/
* elf32-ppc.c (ppc_elf_section_processing): Delete.
(elf_backend_section_processing): Don't define.
(ppc_elf_modify_segment_map): Set p_flags and mark valid. Don't
split on non-exec sections differing in SHF_PPC_VLE. When
splitting segments, mark size invalid.
gas/
* config/tc-ppc.c (md_assemble): Set sh_flags for VLE. Test
ppc_cpu rather than calling ppc_mach to determine VLE mode.
(ppc_frag_check, ppc_handle_align): Likewise use ppc_cpu.
The pr19784 tests fail on ppc32 due to a gcc bug. The failure should
be noticed when building both libpr19784a.so and libpr19784b.so,
rather than ld building a buggy libpr19784a.so that fails at run time.
This patch fixes that by moving the @local ifunc check out of
check_relocs, where a call destination may not yet be known to be
ifunc. The patch also adds a related error for -mbss-plt code.
* elf32-ppc.c (ppc_elf_check_relocs): Move error for @local ifunc..
(ppc_elf_relocate_section): ..to here. Comment. Error on
detecting -mbss-plt -fPIC local ifuncs too.
(ppc_elf_size_dynamic_sections): Comment on unnecessary glink
branch table entries.
* elf64-ppc.c (ppc64_elf_howto_raw <R_PPC64_PLTREL32>): Put
ppc64_elf_unhandled_reloc for special_function.
* elf32-ppc.c (ppc_elf_howto_raw): Similarly for lots of relocs.
VLE is an encoding, not a particular processor architecture, so it
isn't really proper to select insns based on PPC_OPCODE_VLE. For
example
{"evaddw", VX (4, 512), VX_MASK, PPCSPE|PPCVLE, PPCNONE, {RS, RA, RB}},
{"vaddubs", VX (4, 512), VX_MASK, PPCVEC|PPCVLE, PPCNONE, {VD, VA, VB}},
shows two insns that have the same encoding, both available with VLE.
Enabling both with VLE means we can't disassemble the second variant
even if -Maltivec is given rather than -Mspe. Also, we don't check
user assembly against the processor type as well as we could.
Another problem is that when using the VLE encoding, insns from the
main ppc opcode table are not available, except those using opcode 4
and 31. Correcting this revealed two errors in the ld testsuite,
use of "nop" and "rfmci" when -mvle.
This patch fixes those problems in the opcode table, and removes
PPCNONE. I find a plain 0 distracts less from other values.
In addition, I've implemented code to recognize some machine values
from the apuinfo note present in ppc32 objects. It's not a complete
disambiguation since we're lacking info to detect newer chips, but
what we have should help with disassembly.
include/
* elf/ppc.h (APUINFO_SECTION_NAME, APUINFO_LABEL, PPC_APUINFO_ISEL,
PPC_APUINFO_PMR, PPC_APUINFO_RFMCI, PPC_APUINFO_CACHELCK,
PPC_APUINFO_SPE, PPC_APUINFO_EFS, PPC_APUINFO_BRLOCK,
PPC_APUINFO_VLE: Define.
opcodes/
* ppc-dis.c (ppc_opts): Delete extraneous parentheses. Default
cpu for "vle" to e500.
* ppc-opc.c (ALLOW8_SPRG): Remove PPC_OPCODE_VLE.
(NO371, PPCSPE, PPCISEL, PPCEFS, MULHW, DCBT_EO): Likewise.
(PPCNONE): Delete, substitute throughout.
(powerpc_opcodes): Remove PPCVLE from "flags". Add to "deprecated"
except for major opcode 4 and 31.
(vle_opcodes <se_rfmci>): Add PPCRFMCI to flags.
bfd/
* cpu-powerpc.c (powerpc_compatible): Allow bfd_mach_ppc_vle entry
to match other 32-bit archs.
* elf32-ppc.c (_bfd_elf_ppc_set_arch): New function.
(ppc_elf_object_p): Call it.
(ppc_elf_special_sections): Use APUINFO_SECTION_NAME. Fix
overlong line.
(APUINFO_SECTION_NAME, APUINFO_LABEL): Don't define here.
* elf64-ppc.c (ppc64_elf_object_p): Call _bfd_elf_ppc_set_arch.
* bfd-in.h (_bfd_elf_ppc_at_tls_transform,
_bfd_elf_ppc_at_tprel_transform): Move to..
* elf-bfd.h: ..here.
(_bfd_elf_ppc_set_arch): Declare.
* bfd-in2.h: Regenerate.
gas/
* config/tc-ppc.c (PPC_APUINFO_ISEL, PPC_APUINFO_PMR,
PPC_APUINFO_RFMCI, PPC_APUINFO_CACHELCK, PPC_APUINFO_SPE,
PPC_APUINFO_EFS, PPC_APUINFO_BRLOCK, PPC_APUINFO_VLE): Don't define.
(ppc_setup_opcodes): Check vle disables powerpc_opcodes overridden
by vle_opcodes, and that vle flag doesn't enable opcodes. Don't
add vle_opcodes twice.
(ppc_cleanup): Use APUINFO_SECTION_NAME and APUINFO_LABEL.
ld/
* testsuite/ld-powerpc/apuinfo1.s: Delete nop.
* testsuite/ld-powerpc/apuinfo-vle2.s: New.
* testsuite/ld-powerpc/powerpc.exp: Use apuinfo-vle2.s.
H.J. Lu
Maciej W. Rozycki
Alan Modra
Alexander Fedotov-B55613
Yuri Chornovian
Nick Clifton
Andrew Jenner