Adjusting the start of the relro segment in order to make it end
exactly on a page boundary runs into difficulties when sections in the
relro segment are aligned; Adjusting the start by (next_page - end)
sometimes results in more than that adjustment occurring at the end,
overrunning the page boundary. So when that occurs we try a new lower
start position by masking the adjusted start with the maximum section
alignment. However, we didn't consider that this masked start address
may in fact be before the initial relro base, which is silly since
that can only increase padding at the relro end.
I've also moved some calculations closer to where they are used, and
comments closer to the relevant statements.
* ldlang.c (lang_size_sections): When alignment of sections
results in relro base adjustment being too large, don't go lower
than the initial value.
* ldexp.c (fold_binary <DATA_SEGMENT_RELRO_END>): Comment.
* scripttempl/elf.sc (DATA_SEGMENT_ALIGN): Omit SEGMENT_SIZE
alignment when SEGMENT_SIZE is the same as MAXPAGESIZE.
Older compilers that warn wrongly will just need -Wno-error. No way
am I going to init every single field, then have to edit this code
whenever bfd_link_hash_entry changes. Another option, making the
struct static, isn't very nice since it means larger binaries and
worse code.
* emultempl/elf32.em (gld${EMULATION_NAME}_before_allocation): Don't
init ehdr_start_save.
The ehdr_start_save variable does not need to be initialized. However,
not initializing it will trigger a compiler warning when using older
versions of GCC. Self-assignment unfortunately doesn't work for Clang
as Clang has a warning similar to -Winit-self as part of -Wall.
* emultempl/elf32.em (gld*_before_allocation): Zero-initialize
the ehdr_start_save variable.
When src or dst is NULL, the next fread or fwrite will cause a
segmentation fault, so we need to treat it as fatal.
* ldmain.c (main): Use %F instead of %X for einfo.
bfd * elf32-v850.c (v850_set_note): New function. Creates a Renesas
style note entry.
(v850_elf_make_note_section): New function. Creates a note
section.
(v850_elf_create_sections): New function. Create a note section
if one is not already present.
(v850_elf_set_note): New function. Adds a note to a bfd.
(v850_elf_copy_private_bfd_data): New function. Copies V850
notes.
(v850_elf_merge_notes): New function. Merges V850 notes.
(print_v850_note): New function. Displays a V850 note.
(v850_elf_print_notes): New function. Displays all notes attached
to a bfd.
(v850_elf_merge_private_bfd_data): Call v850_elf_merge_notes.
(v850_elf_print_private_bfd_data): Call v850_elf_print_notes.
(v850_elf_fake_sections): Set the type of the V850 note section.
* bfd-in.h (v850_elf_create_sections): Add prototype.
(v850_elf_set_note): Add prototype.
* bfd-in2.h: Regenerate.
binutils* readelf.c (get_machine_flags): Remove deprecated V850 machine
flags.
(get_v850_section_type_name): New function. Handles V850 special
sections.
(get_section_type_name): Add support for V850.
(get_v850_elf_note_type): New function. Returns the name of a
V850 note.
(print_v850_note): New function. Prints a V850 note.
(process_v850_notes): New function. Prints V850 notes.
(process_note_sections): Add support for V850.
binutils/testsute
* binutils-all/objcopy.exp: Skip the strip-10 test for the V850.
gas * config/tc-v850.c (soft_float): New variable.
(v850_data_8): New variable.
(md_show_usage): Add -msoft-float/-mhard-float.
(md_parse_option): Likewise.
(md_begin): Set the default value of soft_float.
(v850_md_end): New function. Creates a note section.
* config/tc-v850.h (md_end): Define.
* doc/c-v850.texi: Document -msoft-float/-mhard-float.
gas/testsuite
* gas/elf/elf.exp: Add special version of the section2 test for
the V850.
* gas/elf/section2.e-v850: New file.
include/elf
* v850.h (EF_RH850_SIMD): Delete deprecated flag.
(EF_RH850_CACHE): Likewise.
(EF_RH850_MMU): Likewise.
(EF_RH850_DATA_ALIGN8): Likewise.
(SHT_RENESAS_IOP): Fix typo in name.
(SHT_RENESAS_INFO): Define.
(V850_NOTE_SECNAME): Define.
(SIZEOF_V850_NOTE): Define.
(V850_NOTE_NAME): Define.
(enum v850_notes): New enum.
(NUM_V850_NOTES): Define.
ld/ChangeLog
2015-02-24 Nick Clifton <nickc@redhat.com>
* Makefile.am (ev850.c): Add dependency upon
$(srcdir)/emultempl/v850elf.em.
(ev850_rh850.c): Likewise.
* Makefile.in: Regenerate.
* emultempl/v850elf.em: New file.
* emulparams/v850.sh (EXTRA_EM_FILE): Define.
* emulparams/v850_rh850.sh (EXTRA_EM_FILE): Define.
* scripttempl/v850.sc: Add .note.renesas section.
* scripttempl/v850_rh850.sc: Likewise.
ld/testsuite
* ld-elf/extract-symbol-1sec.d: Expect to fail on the V850.
ld * scripttempl/avr.sc: Add new user_signatures region. Define and Use
symbols for all region lengths.
* scripttempl/avrtiny.sc: Define and use symbols for all region lengths.
testsuite * ld-avr/region_overflow.d: New test.
* ld-avr/region_overflow.s: Likewise.
LTO output objects have an STT_FILE symbol using the name of the file,
a temporary file. This results in executables that can't be exactly
reproduced, so the file name needs to be dropped. We don't want to
lose all file symbols when linking a mix of lto and non-lto objects as
a file symbol can be used to figure which source file generated a
given local symbol. So lto output objects need to be marked.
I chose to mark lto output objects with a new bfd flag. This flag is
also used to fix a bug in the link-once handling; An object being
loaded after "loading_lto_outputs" is set might be one extracted from
an archive to satisfy new references from lto objects, not an lto
object itself.
The new flag is copied from archive to elements, and the same done
for no_export. This fixes a bug in that --exclude-libs doesn't work
with thin archives. I'm not completely happy with this part of the
patch and may revist this to avoid the hack in
_bfd_look_for_bfd_in_cache.
PR ld/17973
include/
* bfdlink.h (struct bfd_link_info): Delete loading_lto_outputs.
bfd/
* bfd.c (struct bfd): Add lto_output.
* linker.c (_bfd_handle_already_linked): Explicitly test for
objects added by the lto plugin.
* opncls.c (_bfd_new_bfd_contained_in): Copy lto_output and
no_export flags from archive.
* archive.c (open_nested_file): New function, setting lto_output
and no_export, extracted from..
(find_nested_archive): ..here. Flip params. Rename from
_bfd_find_nested_archive.
(_bfd_get_elt_at_filepos): Correct var typo. Use open_nested_file.
(_bfd_look_for_bfd_in_cache): Copy no_export.
* elflink.c (elf_link_add_object_symbols): Remove now unnecessary
my_archive->no_export test.
(elf_link_input_bfd): Drop existing lto_output STT_FILE syms.
Don't use the file name when adding lto_output STT_FILE sym.
* bfd-in2.h: Regenerate.
ld/
* ldlang.h (struct lang_input_statement_flags): Add lto_output.
* ldlang.c (lang_process): Don't set loading_lto_outputs.
* ldfile.c (ldfile_try_open_bfd): Transfer entry flags.lto_output
to bfd.
* plugin.c (add_input_file, add_input_library): Set flags.lto_output.
Gold supports:
--map-whole-files Map whole files to memory (default on 64-bit hosts)
--no-map-whole-files Map relevant file parts to memory (default on 32-bit hosts)
This patch adds --[no-]map-whole-files command line options for gold
compatibility. They are ignored for ld.
* lexsup.c (ld_options): Add --[no-]map-whole-files for gold
option compatibility.
If plugin didn't claim the file, unmap the buffer.
* plugin.c (plugin_input_file_t): Add use_mmap.
(plugin_pagesize): New.
(get_view): Use plugin_pagesize. Set use_mmap if mmap is used.
(plugin_load_plugins): Initialize plugin_pagesize.
(plugin_maybe_claim): Unmap the buffer if plugin didn't claim the
file.
Offset passed to mmap must be a multiple of the page size. This patch
aligns offset passed to mmap.
* plugin.c (get_view): Align offset passed to mmap.
When plugin isn't active or there is no thing more to claim, we don't
need to call bfd_check_format.
* ldfile.c (ldfile_try_open_bfd): Don't call bfd_check_format
if plugin isn't active or there is no thing more to claim.
There is no need to call bfd_check_format. We should just check format
against bfd_object directly.
* plugin.c (plugin_maybe_claim): Check format against bfd_object
directly.
This patch removes the argument of pointer to struct ld_plugin_input_file.
This is the first step to extract a plugin_object_p out of
plugin_maybe_claim for BFD.
* plugin.c: Include "libbfd.h".
(plugin_strdup): New.
(plugin_maybe_claim): Remove the argument of pointer to struct
ld_plugin_input_file. Open and handle input entry.
* plugin.h (plugin_maybe_claim): Updated.
* ldfile.c (ldfile_try_open_bfd): Call plugin_maybe_claim directly
without passing a pointer to struct ld_plugin_input_file.
* ldmain.c: Don't include "libbfd.h".
(add_archive_element): Call plugin_maybe_claim directly without
passing a pointer to struct ld_plugin_input_file.
This patch uses mmap if it is available and works. It also caches the
view buffer for get_view.
* configure.ac: Add AC_FUNC_MMAP.
* config.in: Regenerated.
* configure: Likewise.
* plugin.c: Include <sys/mman.h>.
(MAP_FAILED): New. Defined if not defined.
(PROT_READ): Likewise.
(MAP_PRIVATE): Likewise.
(view_buffer_t): New.
(plugin_input_file_t): Add view_buffer.
(get_view): Try mmap and cache the view buffer.
(plugin_maybe_claim): Initialize view_buffer.
This patch closes fd only if fd != -1.
* plugin.c (release_input_file): Set fd to -1 after closing it.
(plugin_maybe_claim): Close fd only if fd != -1.
This patchs adds plugin_input_file_t to implement get_input_file, get_view
and release_input_file. The maximum memeory overhead per IR input file
are about 40 bytes for plugin_input_file_t plus the memory to store input
IR filename. According to
http://gcc.gnu.org/wiki/whopr/driver
RELEASE_INPUT_FILE: Function pointer to the linker interface that
releases a file descriptor for a claimed input file. The plug-in library
must call this interface for each file descriptor obtained by the "get
input file" interface. It must release all such file descriptors before
returning from the WPA phase.
However, GCC plug-in library doesn't use the "get input file" interface.
It processed the IR input in the claim file handler. Since the the file
descriptor opened for the IR input was unused after the claim file
handler returns and GCC plug-in library before GCC 5 doesn't call the
RELEASE_INPUT_FILE function pointer, ld closed the file descriptor to
avoid leaking file descriptor. But this approach doesn't work with
other plug-in libraries which uses the "get input file", "get view" and
"release input file" interfaces. To avoid file descriptor leak with
GCC prior to GCC 5 and support other plug-in libraries at the same time,
we close the file descriptor only if the input IR file is a bfd_object
file. This scheme doesn't work when a plug-in library needs the file
descriptor and its IR is stored in bfd_object file.
PR ld/17878
* plugin.c: Include <errno.h>.
(errno): New. Declare if needed.
(plugin_input_file_t): New.
(get_input_file): Implemented.
(get_view): Likewise.
(release_input_file): Likewise.
(add_symbols): Updated.
(get_symbols): Likewise.
(plugin_maybe_claim): Allocate a plugin_input_file_t. Close fd
only for a bfd_object input.
Moving .toc out of .got caused us to lose toc sorting and multi-toc
support.
* emultempl/ppc64elf.em (toc_section_name): New var.
(ppc_after_open): Set it.
(ppc_before_allocation): Use it.
(gld${EMULATION_NAME}_after_allocation): Here too.
The changes to reorder sections for better relro protection on powerpc64,
3e2b0f31, 23283c1b, and 5ad18f16, run into a problem with xlc.
xlc -qdatalocal puts global variables into .toc, which means that .toc
must be writable. The simplest way to accomplish this is to edit the
linker script to remove .toc sections from .got on detecting xlc object
files.
bfd/
* elf64-ppc.h (struct ppc64_elf_params): Add "object_in_toc".
* elf64-ppc.c (ppc64_elf_add_symbol_hook): Assume that global symbols
in .toc indicate xlc compiled code that might require a rw .toc.
ld/
* emulparams/elf64ppc.sh (INITIAL_READWRITE_SECTIONS): Define.
* emultempl/ppc64elf.em (params): Init new field.
(ppc_after_open): New function.
(LDEMUL_AFTER_OPEN): Define.
* ldlang.c (lang_final): Whitespace fix.
ld/testsuite/
* ld-powerpc/tocvar.d, * ld-powerpc/tocvar.s: New test.
* ld-powerpc/tocnovar.d, * ld-powerpc/tocnovar.s: New test.
* ld-powerpc/powerpc.exp: Run tocvar and tocnovar.
This patch fixes PR 4643 by allowing symbols in the LENGTH and ORIGIN
fields of MEMORY regions. Previously, only constants and constant
expressions are allowed.
For the AVR target, this helps define memory constraints more
accurately (per device), without having to create a ton of device
specific linker scripts.
ld/
PR 4643
* ldexp.c (fold_name): Fold LENGTH only after
lang_first_phase_enum.
* ldgram.y (memory_spec): Don't evaluate ORIGIN and LENGTH
rightaway.
* ldlang.h (struct memory_region_struct): Add origin_exp and
length_exp fields.
* ldlang.c (lang_do_memory_regions): New.
(lang_memory_region_lookup): Initialize origin_exp and
length_exp fields.
(lang_process): Call lang_do_memory_regions.
ld/testsuite/
* ld-scripts/memory.t: Define new symbol tred.
* ld-scripts/memory_sym.t: New.
* ld-scripts/script.exp: Perform MEMORY with symbols test, and
conditionally check values of linker symbols.
.toc1 is the second level TOC section used by gcc's -mminimal-toc. It
too should be read-only after relocation. Also, the last patch
description mentioned .sbss moving but didn't actually do that, so fix
that problem. .tocbss (whatever that is) was before .sbss previously,
so move that one too.
* emulparams/elf64ppc.sh (OTHER_SDATA_SECTIONS): Use in place of..
(OTHER_BSS_SYMBOLS): ..this.
(OTHER_PLT_RELOC_SECTIONS): Don't define.
(OTHER_GOT_RELOC_SECTIONS): Add rela.toc1 and rela.tocbss.
(OTHER_READWRITE_SECTIONS): Don't define. Move .toc1 to..
(OTHER_RELRO_SECTIONS_2): ..here.
* scripttempl/elf.sc: Move SBSS too when DATA_SDATA.
When creating a linker mapfile (using -Map=MAPFILE), we previously would
always try to evaluate the expression from a PROVIDE statement.
However, this is not always safe, consider:
PROVIDE (foo = 0x10);
PROVIDE (bar = foo);
In this example, if neither 'foo' or 'bar' is needed, then while
generating the linker mapfile evaluating the expression for 'foo' is
harmless (just the value 0x10). However, evaluating the expression for
'bar' requires the symbol 'foo', which is undefined. This used to cause
a fatal error.
This patch changes the behaviour, so that when the destination of the
PROVIDE is not defined (that is the PROVIDE is not going to provide
anything) the expression is not evaluated, and instead a special string
is displayed to indicate that the linker is discarding the PROVIDE
statement.
This change not only fixes the spurious undefined symbol error, but also
means that a user can now tell if a PROVIDE statement has provided
anything by inspecting the linker mapfile, something that could not be
done before.
ld/ChangeLog:
* ldlang.c (print_assignment): Only evaluate the expression for a
PROVIDE'd assignment when the destination is being defined.
Display a special message for PROVIDE'd symbols that are not being
provided.
ld/testsuite/ChangeLog:
* ld-scripts/provide-4.d: New file.
* ld-scripts/provide-4-map.d: New file.
* ld-scripts/provide-4.t: New file.
* ld-scripts/provide-5.d: New file.
* ld-scripts/provide-5.s: New file.
* ld-scripts/provide-5-map.d: New file.
* ld-scripts/provide-5.t: New file.
* ld-scripts/provide.exp: Run the provide-4.d and provide-5.d
tests.
This moves .got too, which requires .sdata and .sbss to move with it,
because these sections share addressing via the toc pointer and with
small-model code must be within a 16-bit signed offset. .plt, .iplt
and .branch_lt must also be moved since they are addressed via a
32-bit offset from the toc pointer, and we might have a very large
.data section.
This change means we may have some bss style sections before the data
segment, necessitating another PT_LOAD header. Also, since _edata is
defined at the end of the data segment it's possible with an empty
.data to have _edata at the end of .plt which looks a little unusual
since .plt is a bss style section. That should only happen rarely in
real world binaries, but does occur in the ld testsuite.
ld/
* emulparams/elf64ppc.sh (BSS_PLT): Don't define.
(OTHER_READWRITE_SECTIONS): Move .branch_lt to..
(OTHER_RELRO_SECTIONS_2): ..here.
(DATA_GOT, SEPARATE_GOTPLT, DATA_SDATA, DATA_PLT,
PLT_BEFORE_GOT): Define.
* scripttempl/elf.sc: Handle DATA_SDATA and DATA_GOT/DATA_PLT/
PLT_BEFORE_GOT combination.
(DATA_GOT, SDATA_GOT): Don't define if either is already defined.
ld/testsuite/
* ld-powerpc/ambiguousv1.d,
* ld-powerpc/ambiguousv1b.d,
* ld-powerpc/ambiguousv2.d,
* ld-powerpc/ambiguousv2b.d,
* ld-powerpc/elfv2exe.d,
* ld-powerpc/elfv2so.d,
* ld-powerpc/tlsexe.r,
* ld-powerpc/tlsexetoc.r,
* ld-powerpc/tlsso.r,
* ld-powerpc/tlstocso.r: Update.
More sections can be read-only after relocation. .opd is an obvious
candidate.
* emulparams/elf64ppc.sh (OTHER_READWRITE_SECTIONS): Move .opd to..
(OTHER_RELRO_SECTIONS_2): ..here, new define.
* scripttempl/elf.sc: Add OTHER_RELRO_SECTIONS_2.
Running lang_common before garbage collection means slightly less work
in garbage collection code, since common symbols should no longer
appear there. It does have the side effect of keeping linker script
symbols (at least those defined outside of sections) global too,
hence some testsuite churn.
bfd/
PR 17165
* elf-bfd.h (ELF_COMMON_DEF): Note that this might be true for
linker script assignments too.
* elflink.c (elf_gc_sweep_symbol): Don't drop ELF_COMMON_DEF syms.
(bfd_elf_gc_mark_dynamic_ref_symbol): Similarly.
ld/
PR 17165
* ldlang.c (lang_process): Run lang_common before lang_gc_sections.
ld/testsuite/
* ld-gc/pr14265.d,
* ld-cris/tls-gc-68.d,
* ld-cris/tls-gc-69.d,
* ld-cris/tls-gc-70.d,
* ld-cris/tls-gc-71.d,
* ld-cris/tls-gc-75.d,
* ld-cris/tls-gc-76.d,
* ld-cris/tls-gc-79.d,
* ld-mmix/bpo-10.d,
* ld-mmix/bpo-11.d: Update.
