Archive element IO is performed on the file of the containing archive,
which leads to the BFD "where" field of archives and their elements
being out of sync with the real file position. (We're talking
traditional archives here, not thin archives.) The old bfd_seek code
recognized this by not attempting to optimize away seeks for
archives. However, there was other code that could return bogus
results. For example, cache.c limits the number of open files by
closing a file and remembering its state once the limit is reached.
If bfd_tell is called on an archive element when the containing
archive is closed, it will return an invalid file pointer.
It's possible to have a valid "where" field for archives by always
using and updating the containing archive BFD. That's what this patch
does. Note that cache.c used to find the containing archive BFD
anyway for the iostream, so we're not really doing extra work, just
transferring it up to the correct abstraction level.
The patch also gets rid of some hacks. bfd_tell was called when
bfd_seek failed, in an attempt to correct "where". That's got to be
papering over another problem, so that code has been removed.
bfd_read also had an "optimiziation" to return early when the number
of bytes was zero, and bfd_seek optimized calls that didn't move the
file pointer. This was covering for a coff_slurp_line_table bug where
IO was attempted on a pe-dll BFD without an iovec.
* bfd.c (struct bfd): Update comment on "where" usage.
* bfdio.c (bfd_bwrite, bfd_stat): Use and update "iovec",
"iostream", and "where" from containing archive file. Return
error on NULL iovec.
(bfd_bread): Similarly, and return error attempted out of
bounds archive element access.
(bfd_tell, bfd_flush): Use and update "iovec", "iostream", and
"where" from containing archive file.
(bfd_seek): Likewise. Return error on NULL iovec. Don't
attempt to optimize away seeks. Don't paper over errors by
calling bfd_tell.
(bfd_get_mtime): Call bfd_stat rather than iovec->bstat.
(bfd_get_size): Likewise.
(bfd_mmap): Operate on and use iovec of containing archive
file. Return error on NULL iovec.
* cache.c (bfd_cache_lookup_worker): Abort if working on
archive element bfd.
(cache_bread_1): Delete bfd parameter, add FILE* parameter.
Don't ignore zero byte reads.
(cache_bread): Look up FILE* in cache here. Error on NULL
lookup.
(cache_bwrite): Rename "where" to "from".
(cache_bmmap): Don't handle archive elements.
* coffcode.h (coff_slurp_line_table): Exit early on zero
lineno count.
* bfd-in2.h: Regenerate.
bfd_get_size and bfd_get_file_size should return the unsigned file
size. Otherwise they return negative values for file >= 2GB with
32-bit ufile_ptr.
bfd/
* bfd-in2.h: Regenerated.
* bfdio.c (bfd_get_size): Change return type to ufile_ptr.
(bfd_get_file_size): Likewise.
binutils/
* objdump.c (dump_relocs_in_section): Cast to ufile_ptr when
comparing against bfd_get_file_size return.
We can't use stat() to get archive element size. Add bfd_get_file_size
to get size for both normal files and archive elements.
bfd/
PR binutils/21519
* bfdio.c (bfd_get_file_size): New function.
* bfd-in2.h: Regenerated.
binutils/
PR binutils/21519
* objdump.c (dump_relocs_in_section): Replace get_file_size
with bfd_get_file_size to get archive element size.
* testsuite/binutils-all/objdump.exp (test_objdump_f): New
proc.
(test_objdump_h): Likewise.
(test_objdump_t): Likewise.
(test_objdump_r): Likewise.
(test_objdump_s): Likewise.
Add objdump tests on archive.
Give these bfd-internal symbols with external linkage a _bfd_ prefix
to avoid collisions in the global symbol namespace.
bfd/ChangeLog:
2017-02-17 Pedro Alves <palves@redhat.com>
* bfdio.c (real_ftell): Rename to ...
(_bfd_real_ftell): ... this.
(real_fseek): Rename to ...
(_bfd_real_fseek): ... this.
(real_fopen): Rename to ...
(_bfd_real_fopen): ... this.
* libbfd-in.h (real_ftell): Rename to ...
(_bfd_real_ftell): ... this.
(real_fseek): Rename to ...
(_bfd_real_fseek): ... this.
(real_fopen): Rename to ...
(_bfd_real_fopen): ... this.
* cache.c, dwarf2.c, opncls.c: Adjust all callers.
* libbfd.h: Regenerate.
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.
* archive.c (_bfd_ar_sizepad): New function. Correctly install and
pad the size field in an archive header.
(_bfd_generic_read_ar_hdr_mag): Use the correct type and scan
function for the archive size field.
(bfd_generic_openr_next_archived_file): Likewise.
(do_slurp_coff_armap): Likewise.
(_bfd_write_archive_contents): Likewise.
(_bfd_bsd44_write_ar_hdr): Use the new function.
(bfd_ar_hdr_from_filesystem): Likewise.
(_bfd_write_archive_contents): Likewise.
(bsd_write_armap): Likewise.
(coff_write_armap): Likewise.
* archive64.c (bfd_elf64_archive_write_armap): Likewise.
* bfdio.c (bfd_bread): Use correct type for archive element
sizes.
* ar.c (open_inarch): Likewise.
(extract_file): Likewise.
* libbfd-in.h (struct areltdata): Use correct types for
parsed_size and extra_size fields.
Prototype _bfd_ar_sizepad function.
* libbfd.h: Regenerate.
* libbfd.c (bfd_realloc_or_free): New function. Performs like
bfd_realloc, but if the (re)allocation fails, the pointer is
freed.
* libbfd-in.h: Prototype.
* libbfd.h: Regenerate.
* bfdio.c (bfd_bwrite): Use the new function.
(bfd_seek): Likewise.
* bfdwin.c:(bfd_get_file_window): Likewise.
* elf-strtab.c (_bfd_elf_strtab_add): Likewise.
* elf32-ppc.c (ppc_elf_relax_section): Likewise.
* elf32-xtensa.c (vsprintf_msg): Likewise.
* mach-o.c (bfd_mach_o_core_fetch_environment): Likewise.
* stabs.c (_bfd_link_seciton_stabs): Likewise.
* vms-misc.c (_bfd_vms_get_record): Likewise.
* vms-tir.c (check_section): Likewise.
* vms.c (vms_new_section_hook): Likewise.
* elf32-arm.c (elf32_arm_section_map_add): Check that the
allocation of sec_data->map succeeded before using it.
* elflink.c (elf_link_output_sym): Do not overwrite finfo->
symshndxbuf until it is known that the reallocation succeeded.
* bfd-in.h: Update copyright.
(bfd_tell): Change return type to file_ptr.
* bfd-in2.h: Re-generate.
* cache.c: Update copyright.
(bfd_cache_lookup_worker): Use real_fseek, do not cast offset
parameter.
(close_one): Use real_ftell.
* bfdio.c: Update copyright.
(real_ftell, real_fseek): New functions.
(bfd_tell): Use real_fseek and real_ftell, change return type to
file_ptr.
(bfd_seek): Use real_ftell and real_fseek, change type of
file_position to a file_ptr.
* libbfd-in.h: Update copyright.
(real_ftell, real_fseek): Declare.
* libbfd.h: Re-generate.
