When using the plugin interface to claim an input file the claim method
from (possible) many plugins can be called on an input file. If these
claim methods read content from the input file then the file offset
stored in the underlying file descriptor will change.
As we share a file descriptor between the plugin interface (created with
dup in ld/plugin.c:plugin_object_p) and the input bfd object, then any
changes to the file offset in the file descriptor will effect the bfd
object. Also, as the changes to the file offset did not originate from
calls through the bfd interface, but instead came from the plugin
directly, then the bfd will not be aware that the file offset has
changed. This is a problem as the bfd library caches the file offset.
If the plugin decides not to claim an input file then, currently, we
leave the bfd in a state where the actual file offset is out of sync
with the cached file offset.
This problem came to light after a recent commit
7d0b9ebc1e (Don't include libbfd.h outside
of bfd, part 6) however, I don't believe that commit actual introduces
the bug, it just exposed the existing issue.
This commit solves the problem by backing up and restoring the file
offset for the file descriptor of the input file. The restore is only
done if the plugin does not claim the input file, as it is in this case
that the bfd library might be used again to try and identify the
unclaimed file.
ld/ChangeLog:
* plugin.c (plugin_call_claim_file): Restore the file offset after
an unsuccessful attempt to claim a file.
* testplug.c (bytes_to_read_before_claim): New global.
(record_read_length): New function, sets new global
bytes_to_read_before_claim.
(parse_option): Handle 'read:<NUMBER>' option.
(onclaim_file): Read file content before checking for claim.
* testsuite/ld-plugin/plugin-30.d: New file.
* testsuite/ld-plugin/plugin.exp: Add new test.
Some messing with plugin code in order to not need arelt_size in
ld code. File descriptor handling in ld/plugin.c is tidied too,
simply duping the open fd rather than opening the file again.
bfd/
* elflink.c: Include plugin-api.h.
* plugin.c (bfd_plugin_open_input): New function, extracted from..
(try_claim): ..here.
* plugin.h: Don't include bfd.h.
(bfd_plugin_open_input): Declare.
binutils/
* ar.c: Include plugin-api.h.
* nm.c: Likewise.
ld/
* plugin.c: Don't include libbfd.h. Include plugin-api.h
before bfd/plugin.h.
(plugin_object_p): Use bfd_plugin_open_input.
If a plugin has been loaded already, we should warn and return, instead
of adding it on the plugin list.
PR ld/20321
* plugin.c (plugin_opt_plugin): Warn and return if plugin has
been loaded already.
* testsuite/ld-plugin/lto.exp: Run PR ld/20321 test.
* testsuite/ld-plugin/pr20321.c: New file.
Also, don't check alignment on symbol from plugin dummy input.
bfd/
PR ld/20276
* elflink.c (elf_link_add_object_symbols): Don't check alignment
on symbol from plugin dummy input.
ld/
PR ld/20276
* plugin.c (plugin_notice): Set non_ir_ref on common symbols.
* testsuite/ld-plugin/lto.exp (lto_link_tests): Add test for
PR ld/20276.
(lto_run_tests): Likewise.
* testsuite/ld-plugin/pass.out: New file.
* testsuite/ld-plugin/pr20276a.c: Likewise.
* testsuite/ld-plugin/pr20276b.c: Likewise.
Many more places use abfd->my_archive rather than bfd_my_archive (abfd),
so let's make the code consistently use the first idiom.
bfd/
* bfd-in.h (bfd_my_archive): Delete.
* bfd-in2.h: Regenerate.
binutils/
* ar.c: Expand uses of bfd_my_archive.
* size.c: Likewise.
ld/
* ldlang.c: Expand uses of bfd_my_archive.
* ldmain.c: Likewise.
* ldmisc.c: Likewise.
* plugin.c: Likewise.
LTO plugin support in plugin_maybe_claim wants to close the IR bfd
after replacing it with the recompiled object, but can't do so for
archive elements due to various pointers that access the archive bfd.
Thin archives have the same problem. They too cannot have their
element bfds closed.
PR ld/20241
bfd/
* archive.c (open_nested_file): Set my_archive.
* bfd.c (_bfd_default_error_handler <%B>): Exclude archive file name
for thin archives.
* bfdio.c (bfd_tell): Don't adjust origin for thin archives.
(bfd_seek): Likewise.
* bfdwin.c (bfd_get_file_window): Likewise.
* cache.c (cache_bmmap): Likewise.
(bfd_cache_lookup_worker): Don't look in my_archive for thin archives.
* mach-o.c (bfd_mach_o_follow_dsym): Don't open my_archive for
thin archives.
* plugin.c (try_claim): Likewise.
* xcofflink.c (xcoff_link_add_dynamic_symbols): Use import path of
file within thin archive, not the archive.
binutils/
* bucomm.c (bfd_get_archive_filename): Return file name within thin
archive.
ld/
* ldmain.c (add_archive_element): Just print file name of file within
thin archives.
* ldmisc.c (vfinfo): Likewise.
* plugin.c (plugin_object_p): Open file within thin archives.
(plugin_maybe_claim): Expand comment.
During archive rescan to resolve symbol references for files added by
LTO, linker add_archive_element callback is called to check if an
archive element should added. After all IR symbols have been claimed,
linker won't claim new IR symbols and shouldn't add the LTO archive
element. This patch updates linker add_archive_element callback to
return FALSE when seeing an LTO archive element during rescan and
changes ELF linker to skip such archive element.
bfd/
PR ld/20103
* cofflink.c (coff_link_check_archive_element): Return TRUE if
linker add_archive_element callback returns FALSE.
* ecoff.c (ecoff_link_check_archive_element): Likewise.
* elf64-ia64-vms.c (elf64_vms_link_add_archive_symbols): Skip
archive element if linker add_archive_element callback returns
FALSE.
* elflink.c (elf_link_add_archive_symbols): Likewise.
* pdp11.c (aout_link_check_ar_symbols): Likewise.
* vms-alpha.c (alpha_vms_link_add_archive_symbols): Likewise.
* xcofflink.c (xcoff_link_check_dynamic_ar_symbols): Likewise.
(xcoff_link_check_ar_symbols): Likewise.
ld/
PR ld/20103
* ldmain.c (add_archive_element): Don't claim new IR symbols
after all IR symbols have been claimed.
* plugin.c (plugin_call_claim_file): Remove no_more_claiming
check.
* testsuite/ld-plugin/lto.exp (pr20103): New proc.
Run PR ld/20103 tests.
* testsuite/ld-plugin/pr20103a.c: New file.
* testsuite/ld-plugin/pr20103b.c: Likewise.
* testsuite/ld-plugin/pr20103c.c: Likewise.
The plugin is called to claim symbols in an archive element from
plugin_object_p. But those symbols aren't needed to create output.
They are defined and referenced only within IR. get_symbols should
return resolution based on IR symbol kinds.
PR ld/20070
* Makefile.am (noinst_LTLIBRARIES): Add libldtestplug4.la.
(libldtestplug4_la_SOURCES): New.
(libldtestplug4_la_CFLAGS): Likewise.
(libldtestplug4_la_LDFLAGS): Likewise.
* Makefile.in: Regenerated.
* plugin.c (get_symbols): Return resolution based on IR symbol
kinds for symbols defined/referenced only within IR.
* testplug4.c: New file.
* ld/testsuite/ld-plugin/pr20070.d: Likewise.
* ld/testsuite/ld-plugin/pr20070a.c: Likewise.
* ld/testsuite/ld-plugin/pr20070b.c: Likewise.
* testsuite/ld-plugin/plugin.exp (plugin4_name): New.
(plugin4_path): Likewise.
Add a test for ld/20070.
When creating a dummy BFD for an IR file, the output BFD is used as
a template for the new BFD, when it needs to be the input BFD passed
into the function when not dealing with a BFD plugin.
On most targets this is not an issue as the input and output formats
are the same anyway, but on MinGW targets, there are two variant
formats used (pe-i386/pe-x86-64 and pei-i386/pei-x86-64) which are
similar but not interchangeable here.
PR ld/18199
* plugin.c (plugin_get_ir_dummy_bfd): Use srctemplate as the
template when calling bfd_create if it does not use the BFD
plugin target vector.
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.
Linker plugin_maybe_claim is the interface of linker plugin support.
This patch extracts linker plugin_maybe_claim into plugin_object_p and
makes it available to BFD via a new function:
void register_ld_plugin_object_p (const bfd_target *(*) (bfd *));
bfd_plugin_object_p calls plugin_object_p registered by linker first. It
adds an enum bfd_plugin_format field and a pointer to plugin dummy BFD so
that plugin_object_p stores plugin dummy BFD to allow plugin_maybe_claim
to retrieve it later.
bfd/
PR ld/17878
* bfd.c (bfd_plugin_format): New.
(bfd): Add plugin_format and plugin_dummy_bfd.
* plugin.c (try_load_plugin): Take a pointer to bfd_boolean
argument to return TRUE if any plugin is found. Set plugin_format.
(has_plugin): New.
(bfd_plugin_target_p): New.
(bfd_plugin_specified_p): Likewise.
(bfd_plugin_target_p): Likewise.
(register_ld_plugin_object_p): Likewise.
(bfd_plugin_set_plugin): Set has_plugin.
(load_plugin): Cache try_load_plugin result.
(bfd_plugin_object_p): Try ld_plugin_object_p first. Check
plugin_format.
* plugin.h (bfd_plugin_target_p): New.
(bfd_plugin_specified_p): Likewise.
(register_ld_plugin_object_p): Likewise.
* bfd-in2.h: Regenerated.
ld/
PR ld/17878
* plugin.c: Include ../bfd/plugin.h.
(plugin_get_ir_dummy_bfd): Call bfd_create with
link_info.output_bfd instead of srctemplate. Copy BFD info
from srctemplate only if it doesn't use BFD plugin target
vector.
(plugin_load_plugins): Call register_ld_plugin_object_p with
(plugin_object_p)
(plugin_maybe_claim): Renamed to ...
(plugin_object_p): This. Return dummy BFD target vector if
input is calimed by plugin library, otherwise return NULL.
Update plugin_format and plugin_dummy_bfd.
(plugin_maybe_claim): New. Use plugin_object_p.
xx
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.
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.
The main aim of this change was to have non_ir_ref set correctly on
new indirect symbols. I could have added a "copy" param to the "notice"
function, so that indirect symbols could be created in plugin_notice,
but it seemed cleaner to create indirect syms earlier and pass them
rather than "string" to "notice".
include/
* bfdlink.h (struct bfd_link_callbacks <notice>): Remove "string"
param, add "inh".
bfd/
* coff-aux.c (coff_m68k_aux_link_add_one_symbol): Only call "notice"
here when not calling the generic add_symbol function. Formatting.
Correct handling of indirect symbols. Update notice call.
* elflink.c (_bfd_elf_notice_as_needed): Update notice call.
* linker.c (_bfd_generic_link_add_one_symbol): Create indirect
symbols early. Update notice call. Add comments regarding weak
symbols vs. indirect.
ld/
* ldmain.c (notice): Update args.
* plugin.c (plugin_notice): Likewise. Follow warning sym link.
Handle new indirect symbol.
When a shared library appears within --start-group/--end-group ld may
only discover a need for loading the library on the second or
subsequent pass over archive libraries, as more objects are extracted.
ld/
PR 17068
* ldlang.c (load_symbols): Always check flags.reload.
(open_input_bfds): Always reload --as-needed shared libraries,
not just when rescanning.
* ldlang.h (struct lang_input_statement_flags): Update reload comment.
* plugin.c (plugin_should_reload): Assume shared library arg.
* plugin.h (plugin_should_reload): Update comment.
ld/testsuite
* ld-elf/pr17068.s: New.
* ld-elf/pr17068a.s: New.
* ld-elf/pr17068b.s: New.
* ld-elf/pr17068c.s: New.
* ld-elf/pr17068d.s: New.
* ld-elf/pr17068e.s: New.
* ld-elf/pr17068ez.s: New.
* ld-elf/elf.exp: Run new test.
* emultempl/elf32.em (id_note_section_size): Use ATTRIBUTE_UNUSED
rather than a dummy assignment for unused parameter.
* plugin.c (get_input_file, release_input_file): Likewise.
ld/
PR ld/14904
* ldmain.c (main): Don't check plugin_load_plugins return.
* lexsup.c (parse_args): Don't check plugin_opt_plugin return.
* plugin.c (dlerror): New. Defined if HAVE_DLFCN_H isn't
defined.
(plugin_opt_plugin): Change return type to void. Stop on
dlopen error and report error with dlerror ().
(plugin_load_plugins): Change return type to void. Stop on
dlsym error and report error with dlerror (). Don't use
set_plugin_error.
(plugin_call_cleanup): Issue an error for each plugin.
* plugin.h (plugin_opt_plugin): Change return type to void.
(plugin_load_plugins): Likewise.
ld/testsuite/
PR ld/14904
* ld-plugin/plugin-2.d: Update expected error message.
* ld-plugin/plugin-4.d: Likewise.
Andrew Burgess
Alan Modra
H.J. Lu
Nick Clifton
Kwok Cheung Yeung
Roland McGrath
Sandra Loosemore