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2022-12-17asan: elf.c:12621:18: applying zero offset to null pointerAlan Modra1-1/+1
That's this line in elf_parse_notes: while (p < buf + size) * elf.c (_bfd_elf_make_section_from_shdr): Don't call elf_parse_notes when sh_size is zero.
2022-12-07_bfd_elf_slurp_secondary_reloc_section sanity checkAlan Modra1-3/+14
* elf.c (_bfd_elf_slurp_secondary_reloc_section): Sanity check section header against file size. Avoid overflow in reloc_count.
2022-12-07Compression tidy and fixesAlan Modra1-2/+2
Tidies: - Move stuff from bfd-in.h and libbfd.c to compress.c - Delete COMPRESS_DEBUG from enum compressed_debug_section_type - Move compress_debug field out of link_info to ld_config. Fixes: - Correct test in bfd_convert_section_setup to use obfd flags, not ibfd. - Apply bfd_applicable_file_flags to compression bfd flags added by gas and ld to the output bfd. bfd/ * bfd-in.h (enum compressed_debug_section_type), (struct compressed_type_tuple), (bfd_get_compression_algorithm), (bfd_get_compression_algorithm_name), * libbfd.c (compressed_debug_section_names), (bfd_get_compression_algorithm), (bfd_get_compression_algorithm_name): Move.. * compress.c: ..to here, deleting COMPRESS_DEBUG from enum compressed_debug_section_type. (bfd_convert_section_setup): Test obfd flags not ibfd for compression flags. * elf.c (elf_fake_sections): Replace link_info->compress_debug test with abfd->flags test. * bfd-in2.h: Regenerate. binutils/ * objcopy.c (copy_file): Tidy setting of bfd compress flags. Expand comment. gas/ * write.c (compress_debug): Test bfd compress flags rather than flag_compress_debug. (write_object_file): Apply bfd_applicable_file_flags to compress debug flags added to output bfd. include/ * bfdlink.h (struct bfd_link_info): Delete compress_debug. ld/ * ld.h (ld_config_type): Add compress_debug. * emultempl/elf.em: Replace references to link_info.compress_debug with config.compress_debug. * lexsup.c (elf_static_list_options): Likewise. * ldmain.c (main): Likewise. Apply bfd_applicable_file_flags to compress debug flags added to output bfd.
2022-12-06Get rid of SEC_ELF_COMPRESSAlan Modra1-76/+55
This flag also isn't needed, except for some sanity checks which we can omit. * elf.c (elf_fake_sections): Don't set SEC_ELF_COMPRESS for compressed debug sections, just leave sh_name as -1. (assign_file_positions_for_non_load_sections), (assign_file_positions_except_relocs): Decide whether a section needs compressing and thus should not have its file offset set by looking at sh_name. (_bfd_elf_assign_file_positions_for_non_load): Similarly decide which sections need compressing. * elflink.c (bfd_elf_final_link): Don't test SEC_ELF_COMPRESS. * merge.c (_bfd_write_merged_section): Likewise. * section.c (SEC_ELF_COMPRESS): Don't define. (SEC_ELF_PURECODE): Renumber. * bfd-in2.h: Regenerate.
2022-12-06Get rid of SEC_ELF_RENAMEAlan Modra1-73/+22
SEC_ELF_RENAME is a flag used to effect section name changes when compressing/decompressing zlib-gnu debug sections. This can be accomplished more directly in one of the objcopy specific bfd functions. Renaming for ld input is simplified too. Ld input object files always have BFD_DECOMPRESS set. bfd/ * compress.c (bfd_convert_section_size): Rename to.. (bfd_convert_section_setup): ..this. Handle objcopy renaming of compressed/decompressed debug sections. * elf.c (_bfd_elf_make_section_from_shdr): Only rename zdebug input for linker. (elf_fake_sections): Don't handle renaming of debug sections for objcopy here. * section.c (SEC_ELF_RENAME): Delete. * bfd-in2.h: Regenerate. binutils/ * objcopy.c (setup_section): Call bfd_convert_section_setup. Don't call bfd_convert_section_size.
2022-12-06Compression header enumAlan Modra1-3/+3
Define an enum instead of using ELFCOMPRESS_ZLIB and ELFCOMPRESS_ZSTD in bfd and binutils, and move some functions from bfd.c to compress.c. When looking at the COFF/PE debug compression support, I wondered about extending it to support zstd. I likely won't do that, but the compression header ch_type field isn't just ELF specific if these headers are to be used in COFF/PE too. bfd/ * bfd.c (bfd_update_compression_header), (bfd_check_compression_header, bfd_get_compression_header_size), (bfd_convert_section_size, bfd_convert_section_contents): Move to.. * compress.c: ..here. (enum compression_type): New. Use it throughout file. * elf.c (_bfd_elf_make_section_from_shdr): Replace uses of ELFCOMPRESS_ZLIB and ELFCOMPRESS_ZSTD with ch_compress_zlib and ch_compress_zstd. * bfd-in2.h: Regenerate. binutils/ * readelf.c (process_section_headers, dump_section_as_strings), (dump_section_as_bytes, load_specific_debug_section): Replace uses of ELFCOMPRESS_ZLIB and ELFCOMPRESS_ZSTD with ch_compress_zlib and ch_compress_zstd.
2022-12-04Renaming .debug to .zdebug and vice versaAlan Modra1-30/+4
Move a couple of elf.c functions to compress.c. * compress.c (bfd_debug_name_to_zdebug): New inline function. (bfd_zdebug_name_to_debug): Likewise. * elf.c (convert_debug_to_zdebug, convert_zdebug_to_debug): Delete. (_bfd_elf_make_section_from_shdr, elf_fake_sections), (_bfd_elf_assign_file_positions_for_non_load): Adjust to suit. * coffgen.c (make_a_section_from_file): Use new inlines here.
2022-11-15bfd: linker: merge .sframe sectionsIndu Bhagat1-0/+32
The linker merges all the input .sframe sections. When merging, the linker verifies that all the input .sframe sections have the same abi/arch. The linker uses libsframe library to perform key actions on the .sframe sections - decode, read, and create output data. This implies buildsystem changes to make and install libsframe before libbfd. The linker places the output .sframe section in a new segment of its own: PT_GNU_SFRAME. A new segment is not added, however, if the generated .sframe section is empty. When a section is discarded from the final link, the corresponding entries in the .sframe section for those functions are also deleted. The linker sorts the SFrame FDEs on start address by default and sets the SFRAME_F_FDE_SORTED flag in the .sframe section. This patch also adds support for generation of SFrame unwind information for the .plt* sections on x86_64. SFrame unwind info is generated for IBT enabled PLT, lazy/non-lazy PLT. The existing linker option --no-ld-generated-unwind-info has been adapted to include the control of whether .sframe unwind information will be generated for the linker generated sections like PLT. Changes to the linker script have been made as necessary. ChangeLog: * Makefile.def: Add install dependency on libsframe for libbfd. * Makefile.in: Regenerated. * bfd/Makefile.am: Add elf-sframe.c * bfd/Makefile.in: Regenerated. * bfd/bfd-in2.h (SEC_INFO_TYPE_SFRAME): Regenerated. * bfd/configure: Regenerate. * bfd/configure.ac: Add elf-sframe.lo. * bfd/elf-bfd.h (struct sframe_func_bfdinfo): New struct. (struct sframe_dec_info): Likewise. (struct sframe_enc_info): Likewise. (struct elf_link_hash_table): New member for encoded .sframe object. (struct output_elf_obj_tdata): New member. (elf_sframe): New access macro. (_bfd_elf_set_section_sframe): New declaration. * bfd/elf.c (get_segment_type): Handle new segment PT_GNU_SFRAME. (bfd_section_from_phdr): Likewise. (get_program_header_size): Likewise. (_bfd_elf_map_sections_to_segments): Likewise. * bfd/elf64-x86-64.c (elf_x86_64_link_setup_gnu_properties): Add contents to the .sframe sections or .plt* entries. * bfd/elflink.c (elf_section_ignore_discarded_relocs): Handle SEC_INFO_TYPE_SFRAME. (_bfd_elf_default_action_discarded): Handle .sframe section. (elf_link_input_bfd): Merge .sframe section. (bfd_elf_final_link): Write the output .sframe section. (bfd_elf_discard_info): Handle discarding .sframe section. * bfd/elfxx-x86.c (_bfd_x86_elf_size_dynamic_sections): Create .sframe section for .plt and .plt.sec. (_bfd_x86_elf_finish_dynamic_sections): Handle .sframe from .plt* sections. * bfd/elfxx-x86.h (PLT_SFRAME_FDE_START_OFFSET): New definition. (SFRAME_PLT0_MAX_NUM_FRES): Likewise. (SFRAME_PLTN_MAX_NUM_FRES): Likewise. (struct elf_x86_sframe_plt): New structure. (struct elf_x86_link_hash_table): New member. (struct elf_x86_init_table): New members for .sframe creation. * bfd/section.c: Add new definition SEC_INFO_TYPE_SFRAME. * binutils/readelf.c (get_segment_type): Handle new segment PT_GNU_SFRAME. * ld/ld.texi: Update documentation for --no-ld-generated-unwind-info. * ld/scripttempl/elf.sc: Support .sframe sections. * ld/Makefile.am (TESTSFRAMELIB): Use it. (check-DEJAGNU): Likewise. * ld/Makefile.in: Regenerated. * ld/configure.ac (TESTSFRAMELIB): Set to the .so or .a like TESTBFDLIB. * ld/configure: Regenerated. * bfd/elf-sframe.c: New file. include/ChangeLog: * elf/common.h (PT_GNU_SFRAME): New definition. * elf/internal.h (struct elf_segment_map): Handle new segment type PT_GNU_SFRAME. ld/testsuite/ChangeLog: * ld/testsuite/ld-bootstrap/bootstrap.exp: Add SFRAMELIB. * ld/testsuite/ld-aarch64/aarch64-elf.exp: Add new test sframe-simple-1. * ld/testsuite/ld-aarch64/sframe-bar.s: New file. * ld/testsuite/ld-aarch64/sframe-foo.s: Likewise. * ld/testsuite/ld-aarch64/sframe-simple-1.d: Likewise. * ld/testsuite/ld-sframe/sframe-empty.d: New test. * ld/testsuite/ld-sframe/sframe-empty.s: New file. * ld/testsuite/ld-sframe/sframe.exp: New testsuite. * ld/testsuite/ld-x86-64/sframe-bar.s: New file. * ld/testsuite/ld-x86-64/sframe-foo.s: Likewise. * ld/testsuite/ld-x86-64/sframe-simple-1.d: Likewise. * ld/testsuite/ld-x86-64/sframe-plt-1.d: Likewise. * ld/testsuite/ld-x86-64/sframe-simple-1.d: Likewise. * ld/testsuite/ld-x86-64/x86-64.exp: Add new tests - sframe-simple-1, sframe-plt-1. * ld/testsuite/lib/ld-lib.exp: Add new proc to check if assembler supports SFrame section. * ld/testsuite/ld-sframe/discard.d: New file. * ld/testsuite/ld-sframe/discard.ld: Likewise. * ld/testsuite/ld-sframe/discard.s: Likewise.
2022-10-26Correct ELF reloc size sanity checkAlan Modra1-6/+11
The external reloc size check was wrong. Here asect is the code/data section, not the reloc section. So using this_hdr gave the size of the code/data section. * elf.c (_bfd_elf_get_reloc_upper_bound): Properly get external size from reloc headers.
2022-10-19Fix an illegal memory access when parsing an ELF file containing corrupt ↵Nick Clifton1-1/+3
symbol version information. PR 29699 * elf.c (_bfd_elf_slurp_version_tables): Fail if the sh_info field of the section header is zero.
2022-10-04Support objcopy changing compression to or from zstdAlan Modra1-45/+48
Commit 2cac01e3ffff lacked support for objcopy changing compression style. Add that support, which meant a rewrite of bfd_compress_section_contents. In the process I've fixed some memory leaks. * compress.c (bfd_is_section_compressed_info): Rename from bfd_is_section_compressed_with_header and add ch_type param to return compression header ch_type field. Update all callers. (decompress_section_contents): Remove buffer and size params. Rewrite. Update callers. (bfd_init_section_compress_status): Free contents on failure. (bfd_compress_section): Likewise. * elf.c (_bfd_elf_make_section_from_shdr): Support objcopy changing between any of the three compression schemes. Report "unable to compress/decompress" rather than "unable to initialize compress/decompress status" on compress/decompress failures. * bfd-in2.h: Regenerate.
2022-10-04Re: compress .gnu.debuglto_.debug_* sections if requestedAlan Modra1-3/+4
Enable zlib-gnu compression for .gnu.debuglto_.debug_*. This differs from zlib-gnu for .debug_* where the name is changed to .zdebug_*. The name change isn't really needed. bfd/ * elf.c (elf_fake_sections): Replace "." with ".z" in debug section names only when name was ".d*", ie. ".debug_*". (_bfd_elf_assign_file_positions_for_non_load): Likewise. gas/ * write.c (compress_debug): Compress .gnu.debuglto_.debug_* for zlib-gnu too. Compress .gnu.linkonce.wi.*.
2022-10-04compress .gnu.debuglto_.debug_* sections if requestedMartin Liska1-4/+3
Right now, when using LTO, the intermediate object files do contain debug info in sections starting with .gnu.debuglto_ prefix and are not compressed when --compress-debug-sections is used. It's a mistake and we can save quite some disk space. The following example comes from tramp3d when the corresponding LTO sections are compressed with zlib: $ bloaty tramp3d-v4-v2.o -- tramp3d-v4.o FILE SIZE VM SIZE -------------- -------------- +83% +10 [ = ] 0 [Unmapped] -68.0% -441 [ = ] 0 .gnu.debuglto_.debug_line -52.3% -759 [ = ] 0 .gnu.debuglto_.debug_line_str -62.4% -3.24Ki [ = ] 0 .gnu.debuglto_.debug_abbrev -64.8% -1.12Mi [ = ] 0 .gnu.debuglto_.debug_info -88.8% -4.58Mi [ = ] 0 .gnu.debuglto_.debug_str -27.7% -5.70Mi [ = ] 0 TOTAL bfd/ChangeLog: * elf.c (_bfd_elf_make_section_from_shdr): Compress all debug info sections. gas/ChangeLog: * write.c (compress_debug): Compress also ".gnu.debuglto_.debug_" if the compression algorithm is different from zlib-gnu.
2022-09-26binutils, gdb: support zstd compressed debug sectionsFangrui Song1-0/+12
PR29397 PR29563: Add new configure option --with-zstd which defaults to auto. If pkgconfig/libzstd.pc is found, define HAVE_ZSTD and support zstd compressed debug sections for most tools. * bfd: for addr2line, objdump --dwarf, gdb, etc * gas: support --compress-debug-sections=zstd * ld: support ELFCOMPRESS_ZSTD input and --compress-debug-sections=zstd * objcopy: support ELFCOMPRESS_ZSTD input for --decompress-debug-sections and --compress-debug-sections=zstd * gdb: support ELFCOMPRESS_ZSTD input. The bfd change references zstd symbols, so gdb has to link against -lzstd in this patch. If zstd is not supported, ELFCOMPRESS_ZSTD input triggers an error. We can avoid HAVE_ZSTD if binutils-gdb imports zstd/ like zlib/, but this is too heavyweight, so don't do it for now. ``` % ld/ld-new a.o ld/ld-new: a.o: section .debug_abbrev is compressed with zstd, but BFD is not built with zstd support ... % ld/ld-new a.o --compress-debug-sections=zstd ld/ld-new: --compress-debug-sections=zstd: ld is not built with zstd support % binutils/objcopy --compress-debug-sections=zstd a.o b.o binutils/objcopy: --compress-debug-sections=zstd: binutils is not built with zstd support % binutils/objcopy b.o --decompress-debug-sections binutils/objcopy: zstd.o: section .debug_abbrev is compressed with zstd, but BFD is not built with zstd support ... ```
2022-09-26PR29613, use of uninitialized value in objcopyAlan Modra1-8/+9
PR 29613 * elf.c (_bfd_elf_write_secondary_reloc_section): Trim sh_size back to relocs written. Use better types for vars.
2022-09-26stab nearest_line bfd_malloc_and_get_sectionAlan Modra1-0/+1
bfd_malloc_and_get_section performs some sanity checks on the section size before allocating memory. This patch avails the stab nearest_line code of that sanity checking, and tidies up memory afterward. * coffgen.c (_bfd_coff_close_and_cleanup): Call _bfd_stab_cleanup. * elf.c (_bfd_elf_close_and_cleanup): Likewise. * syms.c (_bfd_stab_section_find_nearest_line): Set *pinfo earlier. Use bfd_malloc_and_get_section. Free malloc'd buffers on failure. Malloc indextable. (_bfd_stab_cleanup): New function. * libbfd-in.h (_bfd_stab_cleanup): Declare. * libbfd.h: Regnerate.
2022-09-23Don't attempt to compress bss sectionsAlan Modra1-1/+2
It doesn't make sense to try to compress a section without contents since those sections take no space on disk. Compression can only increase the disk image size. * coffgen.c (make_a_section_from_file): Exclude !SEC_HAS_CONTENTS sections from compression and decompression. * elf.c (_bfd_elf_make_section_from_shdr): Likewise.
2022-09-21PR29566, objdump -p considers an empty .gnu.version_r invalidAlan Modra1-5/+6
Allow and ignore an empty section. PR 29566 * elf.c (bfd_section_from_shdr): Don't set elf_dynverdef or elf_dynverref for empty sections. (_bfd_elf_slurp_version_tables): Remove now redundant tests.
2022-09-09Support debuginfo files with empty group sections.Nick Clifton1-1/+5
PR 29532 bfd * elf.c (setup_group): Do not return false if there is no group information available. bionutils* objcopy.c (setup_section): Leave group sections intact when creating separate debuginfo files.
2022-09-06bfd: Add bfd_find_nearest_line_with_altAaron Merey1-5/+27
bfd_find_nearest_line_with_alt functions like bfd_find_nearest_line with the addition of a parameter for specifying the filename of a supplementary debug file such as one referenced by .gnu_debugaltlink or .debug_sup. This patch focuses on implementing bfd_find_nearest_line_with_alt support for ELF/DWARF2 .gnu_debugaltlink. For other targets this function simply sets the invalid_operation bfd_error.
2022-08-23SHT_RELR sh_link and sh_infoAlan Modra1-0/+1
I don't think it makes any sense for a SHT_RELR section to specify a symbol table with sh_link. SHT_RELR relocations don't use symbols. There is no real need to specify sh_info either, SHT_RELR is not for relocatable object files. Anyway, fuzzers of course don't restrict themselves to even half-sensible objects. So they found a hole in objcopy using a non-alloc SHT_RELR in an ET_EXEC. In that case BFD set up the SHT_RELR section as if it were a SHT_REL against the sh_info target section. When it came to reading in the target section relocs, the count was horribly wrong which caused a buffer overflow. * elf.c (bfd_section_from_shdr <SHT_RELR>): Always just make a normal section, don't treat it as a reloc section.
2022-08-23Re: bfd_elf_set_group_contents assertionAlan Modra1-5/+19
Further to commit 7744e3278b9f. * elf.c (bfd_elf_set_group_contents): Restrict loc in loop writing contents, and add another assertion.
2022-08-17bfd_elf_set_group_contents assertionAlan Modra1-1/+6
objcopy of broken SHT_GROUP sections shouldn't write garbage. * elf.c (bfd_elf_set_group_contents): If number of entries is unexpected, fill out section with zeros.
2022-08-17elf.c tidyAlan Modra1-138/+160
Swap params of is_note, so they are section, segment like others used in rewrite_elf_program_header. Whitespace fixes, plus wrapping of overlong lines.
2022-08-16PR29495, rewrite_elf_program_header loopingAlan Modra1-65/+75
This patch, in order of significance: 1) Replaces some macros with inline functions. 2) Those inline functions catch and avoid arithmetic overflows when comparing addresses. 3) When assigning sections to segments (IS_SECTION_IN_INPUT_SEGMENT) use bed->want_p_paddr_set_to_zero to decide whether lma vs p_paddr or vma vs p_vaddr should be tested. When remapping, use the same test, and use is_note rather than the more restrictive IS_COREFILE_NOTE. It's important that the later tests not be more restrictive. If they are it can lead to the situation triggered by the testcases, where a section seemingly didn't fit and thus needed a new mapping. It didn't fit the new mapping either, and this repeated until memory exhausted. PR 29495 * elf.c (SEGMENT_END, SECTION_SIZE, IS_CONTAINED_BY_VMA): Delete. (IS_CONTAINED_BY_LMA, IS_NOTE, IS_COREFILE_NOTE): Delete. (segment_size, segment_end, section_size): New inline function. (is_contained_by, is_note): Likewise. (rewrite_elf_program_header): Use new functions.
2022-08-05asan: ppc64_elf_get_synthetic_symtab heap buffer overflowAlan Modra1-8/+3
Fuzzed input files with sizes of .dynamic not a multiple of dynamic tag size can result in reading past the end of the buffer with the current simple checks. Fix that, and use the same check in other files that process input object .dynamic section. (There is no need for buffer overflow checks in the linker's generated .dynamic section.) * elf32-ppc.c (ppc_elf_get_synthetic_symtab): Sanity check .dynamic content buffer reads. * elf64-ppc.c (ppc64_elf_get_synthetic_symtab): Likewise. * elf64-ia64-vms.c (elf64_vms_link_add_object_symbols): Likewise. * elf.c (_bfd_elf_print_private_bfd_data): Simplify .dynamic buffer sanity checks. * elflink.c (elf_link_add_object_symbols): Avoid possible UB subtracting sizeof_dyn from pointer.
2022-08-04Don't use BFD_VMA_FMT in binutilsAlan Modra1-1/+1
BFD_VMA_FMT can't be used in format strings that need to be translated, because the translation won't work when the type of bfd_vma differs from the machine used to compile .pot files. We've known about this for a long time, but patches slip through review. So just get rid of BFD_VMA_FMT, instead using the appropriate PRId64, PRIu64, PRIx64 or PRIo64 and SCN variants for scanf. The patch is mostly mechanical, the only thing requiring any thought is casts needed to preserve PRId64 output from bfd_vma values, or to preserve one of the unsigned output formats from bfd_signed_vma values.
2022-08-03elf: Reset alignment for each PT_LOAD segmentH.J. Lu1-3/+4
Reset alignment for each PT_LOAD segment to avoid using alignment from the previous PT_LOAD segment. bfd/ PR ld/29435 * elf.c (assign_file_positions_for_load_sections): Reset alignment for each PT_LOAD segment. ld/ PR ld/29435 * testsuite/ld-elf/pr29435.d: New file. * testsuite/ld-elf/pr29435.s: Likewise.
2022-08-02ELF: emit symbol table when there are relocationsJan Beulich1-2/+4
Even when there are no symbols (e.g. all relocations being against absolute values), a symbol table (with just the first placeholder entry) needs to be emitted. Otherwise tools like objdump won't properly process the relocations. The respective checks in assign_section_numbers() and _bfd_elf_compute_section_file_positions() support also this view. Oddly enough so far HAS_RELOC was only set when reading in an object file, but not when generating one anew; the flag would only have been cleared when no relocations were found (anymore). While there also amend the affected function's leading comment to also mention gas.
2022-07-06elf: Copy p_align of PT_GNU_STACK for stack alignmentH.J. Lu1-1/+3
commit 74e315dbfe5200c473b226e937935fb8ce391489 Author: H.J. Lu <hjl.tools@gmail.com> Date: Mon Dec 13 19:46:04 2021 -0800 elf: Set p_align to the minimum page size if possible may ignore p_align of PT_GNU_STACK when copying ELF program header if the maximum page size is larger than p_align of PT_LOAD segments. Copy p_align of PT_GNU_STACK since p_align of PT_GNU_STACK describes stack alignment, not page size, PR binutils/29319 * elf.c (copy_elf_program_header): Copy p_align of PT_GNU_STACK for stack alignment.
2022-05-26ld: add --package-metadataLuca Boccassi1-2/+6
Generate a .note.package FDO package metadata ELF note, following the spec: https://systemd.io/ELF_PACKAGE_METADATA/ If the jansson library is available at build time (and it is explicitly enabled), link ld to it, and use it to validate that the input is correct JSON, to avoid writing garbage to the file. The configure option --enable-jansson has to be used to explicitly enable it (error out when not found). This allows bootstrappers (or others who are not interested) to seamlessly skip it without issues.
2022-05-13Fix "gdb --write" with core filesPedro Alves1-7/+2
If you load a core file into GDB with the --write option, or "set write on" (equivalent), and then poke memory expecting it to patch the core binary, you'll notice something odd -- the write seems to succeed, but in reality, it doesn't. The value you wrote doesn't persist. Like so: $ gdb -q --write -c testsuite/outputs/gdb.base/patch/gcore.test [New LWP 615986] Core was generated by `/home/pedro/gdb/build/gdb/testsuite/outputs/gdb.base/patch/patch'. Program terminated with signal SIGTRAP, Trace/breakpoint trap. #0 0x0000555555555131 in ?? () (gdb) p *(unsigned char *)0x0000555555555131 = 1 $1 = 1 '\001' (gdb) p *(unsigned char *)0x0000555555555131 $2 = 185 '\271' (gdb) Diffing hexdumps of before/after patching, reveals that a "0x1" was actually written somewhere in the file. The problem is that the "0x1" was written at the wrong offset in the file... That happens because _bfd_elf_set_section_contents does this to seek to the section's offset: pos = hdr->sh_offset + offset; if (bfd_seek (abfd, pos, SEEK_SET) != 0 || bfd_bwrite (location, count, abfd) != count) return false; ... and 'hdr->sh_offset' is zero, so we seek to just OFFSET, which is incorrect. The reason 'hdr->sh_offset' is zero is that kernel-generated core files normally don't even have a section header table (gdb-generated ones do, but that's more an accident than a feature), and indeed elf_core_file_p doesn't even try to read sections at all: /* Core files are simply standard ELF formatted files that partition the file using the execution view of the file (program header table) rather than the linking view. In fact, there is no section header table in a core file. The process status information (including the contents of the general register set) and the floating point register set are stored in a segment of type PT_NOTE. We handcraft a couple of extra bfd sections that allow standard bfd access to the general registers (.reg) and the floating point registers (.reg2). */ bfd_cleanup elf_core_file_p (bfd *abfd) Changing _bfd_elf_set_section_contents from: pos = hdr->sh_offset + offset; to: pos = section->filepos + offset; fixes it. If we do that however, the tail end of _bfd_elf_set_section_contents ends up as a copy of _bfd_generic_set_section_contents, so just call the latter, thus eliminating some duplicate code. New GDB testcase included, which exercises both patching an executable and patching a core file. Patching an executable already works without this fix, because in that case BFD reads in the sections table. Still, we had no testcase for that yet. In fact, we have no "set write on" testcases at all, this is the first one. Tested on x86-64 GNU/Linux, gdb, ld, binutils, and gas. Bug: https://sourceware.org/bugzilla/show_bug.cgi?id=18227 Change-Id: I0f49f58b48aabab2e269f2959b8fd8a7fe36fdce
2022-05-03Add a linker warning when creating potentially dangerous executable ↵Nick Clifton1-0/+23
segments. Add tests, options to disabke and configure switches to choose defaults.
2022-04-27Create pseudo sections for NT_ARM_TLS notes on FreeBSD.John Baldwin1-0/+3
bfd/ChangeLog: * elf.c (elfcore_grok_freebsd_note): Handle NT_ARM_TLS notes.
2022-04-01Use pseudosections for NT_FREEBSD_X86_SEGBASES core dump notes.John Baldwin1-0/+14
This includes adding pseudosections when reading a core dump as well as support for writing out a core dump note from a pseudosection. bfd/ChangeLog: * elf-bfd.h (elfcore_write_x86_segbases): New. * elf.c (elfcore_grok_freebsd_note): Add pseudosections for NT_FREEBSD_X86_SEGBASES register notes. (elfcore_write_x86_segbases): New. (elfcore_write_register_note): Write NT_FREEBSD_X86_SEGBASES register notes.
2022-04-01elfcore_grok_freebsd_note: Remove checks of note->namesz.John Baldwin1-8/+2
This function is only called if the note name is "FreeBSD", so checking the name size is unnecessary. bfd/ChangeLog: * elf.c (elfcore_grok_freebsd_note): Remove checks for namesz.
2022-02-16ld: Support customized output section typeFangrui Song1-1/+3
bfd/ PR ld/28841 * bfd-in2.h (struct bfd_section): Add type. (discarded_section): Add field. * elf.c (elf_fake_sections): Handle bfd_section::type. * section.c (BFD_FAKE_SECTION): Add field. * mri.c (mri_draw_tree): Update function call. ld/ PR ld/28841 * ld.texi: Document new output section type. * ldlex.l: Add new token TYPE. * ldgram.y: Handle TYPE=exp. * ldlang.h: Add type_section to list of section types. * ldlang.c (lang_add_section): Handle type_section. (map_input_to_output_sections): Handle type_section. * testsuite/ld-scripts/output-section-types.t: Add tests. * testsuite/ld-scripts/output-section-types.d: Update.
2022-02-16What to do when sh_addralign isn't a power of twoAlan Modra1-6/+7
BFD generally doesn't handle anything but a power of two section alignment, and ELF sh_addralign is required to be an integral power of two (or zero) by the ELF spec. Of course this is ignored by fuzzers, and because bfd_log2 rounds up, we can end up with alignment_power being 32 on a 32-bit object or 64 on a 64-bit object. That then triggers ubsan warnings in places like bfd_update_compression_header where we want to convert from alignment_power back to an alignment. I suppose we could reject object files that have non-compliant sh_addralign, but I think it's also reasonable to use the greatest power of two divisor of sh_addralign, ie. the rightmost 1 bit. * elf.c (_bfd_elf_make_section_from_shdr): Use greatest power of two divisor of sh_addralign. (_bfd_elf_assign_file_position_for_section): Likewise. (assign_file_positions_for_non_load_sections): Likewise.
2022-02-05Detect .eh_frame_hdr earlier for SIZEOF_HEADERSAlan Modra1-2/+16
Current code detects the need for PT_GNU_EH_FRAME using a field set by _bfd_elf_discard_section_eh_frame_hdr, which is called fairly late in the linking process. Use the elf hash table eh_info instead, which is set up earlier by size_dynamic_sections. * elf-bfd.h (struct output_elf_obj_tdata): Delete eh_frame_hdr. (elf_eh_frame_hdr): Don't define. (_bfd_elf_discard_section_eh_frame_hdr): Update prototype. * elf-eh-frame.c (_bfd_elf_discard_section_eh_frame_hdr): Delete abfd parameter. Don't set elf_eh_frame_hdr. * elf.c (elf_eh_frame_hdr): New function. (get_program_header_size): Adjust elf_eh_frame_hdr call. (_bfd_elf_map_sections_to_segments): Likewise.
2022-01-12elf: Add size_relative_relocs and finish_relative_relocsH.J. Lu1-2/+12
On some targets, the DT_RELR section size can be computed only after all symbols addresses can be determined. Set the preliminary DT_RELR section size before mapping sections to segments and set the final DT_RELR section size after regular symbol processing is done. * elf-bfd.h (elf_backend_data): Add size_relative_relocs and finish_relative_relocs. * elf.c (_bfd_elf_map_sections_to_segments): Call size_relative_relocs if DT_RELR is enabled. * elflink.c (bfd_elf_final_link): Call finish_relative_relocs after regular symbol processing is finished if DT_RELR is enabled. * elfxx-target.h (elf_backend_size_relative_relocs): New. (elf_backend_finish_relative_relocs): Likewise. (elfNN_bed): Add elf_backend_size_relative_relocs and elf_backend_finish_relative_relocs.
2022-01-12elf: Pass need_layout to _bfd_elf_map_sections_to_segmentsH.J. Lu1-3/+6
On some targets, the DT_RELR section size can be computed only after all symbols addresses can be determined. Update ldelf_map_segments to pass need_layout to _bfd_elf_map_sections_to_segments which will size DT_RELR section and set need_layout to true if the DT_RELR section size is changed. bfd/ * elf-bfd.h (_bfd_elf_map_sections_to_segments): Add a bool pointer argument. * elf.c (_bfd_elf_map_sections_to_segments): Add a bool pointer argument to indicate if section layout needs update. (assign_file_positions_for_load_sections): Pass NULL to _bfd_elf_map_sections_to_segments. * elflink.c (_bfd_elf_strip_zero_sized_dynamic_sections): Pass NULL to _bfd_elf_map_sections_to_segments. ld/ * ldelfgen.c (ldelf_map_segments): Pass &need_layout to _bfd_elf_map_sections_to_segments.
2022-01-12elf: Add .relr.dyn to special_sections_rH.J. Lu1-0/+1
* elf.c (special_sections_r): Add .relr.dyn.
2022-01-05elf: Set p_align to the minimum page size if possibleH.J. Lu1-2/+69
Currently, on 32-bit and 64-bit ARM, it seems that ld generates p_align values of 0x10000 even if no section alignment is greater than 0x1000. The issue is more general and probably affects other targets with multiple page sizes. While file layout absolutely must take 64K page size into account, that does not have to be reflected in the p_align value. If running on a 64K kernel, the file will be loaded at a 64K page boundary by necessity. On a 4K kernel, 64K alignment is not needed. The glibc loader has been fixed to honor p_align: https://sourceware.org/bugzilla/show_bug.cgi?id=28676 similar to kernel: commit ce81bb256a224259ab686742a6284930cbe4f1fa Author: Chris Kennelly <ckennelly@google.com> Date: Thu Oct 15 20:12:32 2020 -0700 fs/binfmt_elf: use PT_LOAD p_align values for suitable start address This means that on 4K kernels, we will start to do extra work for 64K p_align, but this pointless for pretty much all binaries (whose section alignment rarely exceeds 16). The minimum page size is used, instead of the maximum section alignment due to this glibc bug: https://sourceware.org/bugzilla/show_bug.cgi?id=28688 It has been fixed in glibc 2.35. But linker output must work on existing glibc binaries. 1. Set p_align to the minimum page size while laying out segments aligning to the maximum page size or section alignment. The run-time loader can align segments to the minimum page size or above, depending on system page size. 2. If -z max-page-size=NNN is used, p_align will be set to the maximum page size or the largest section alignment. 3. If a section requires alignment higher than the minimum page size, don't set p_align to the minimum page size. 4. If a section requires alignment higher than the maximum page size, set p_align to the section alignment. 5. For objcopy, when the minimum page size != the maximum page size, p_align may be set to the minimum page size while segments are aligned to the maximum page size. In this case, the input p_align will be ignored and the maximum page size will be used to align the ouput segments. 6. Update linker to disallow the common page size > the maximum page size. 7. Update linker to avoid the common page size > the maximum page size. 8. Adjust pru_irq_map-1.d to expect p_align == sh_addralign: Section Headers: [Nr] Name Type Addr Off Size ES Flg Lk Inf Al [ 0] NULL 00000000 000000 000000 00 0 0 0 [ 1] .text PROGBITS 20000000 00007c 000004 00 AX 0 0 4 ... Program Headers: Type Offset VirtAddr PhysAddr FileSiz MemSiz Flg Align LOAD 0x000074 0x00000000 0x00000000 0x00008 0x00008 RW 0x1 LOAD 0x00007c 0x20000000 0x20000000 0x00004 0x00004 R E 0x4 vs. Section Headers: [Nr] Name Type Addr Off Size ES Flg Lk Inf Al [ 0] NULL 00000000 000000 000000 00 0 0 0 [ 1] .text PROGBITS 20000000 00007c 000004 00 AX 0 0 4 ... Program Headers: Type Offset VirtAddr PhysAddr FileSiz MemSiz Flg Align LOAD 0x000074 0x00000000 0x00000000 0x00008 0x00008 RW 0x1 LOAD 0x00007c 0x20000000 0x20000000 0x00004 0x00004 R E 0x1 To enable this linker optimization, the backend should define ELF_P_ALIGN to ELF_MINPAGESIZE. bfd/ PR ld/28689 PR ld/28695 * elf-bfd.h (elf_backend_data): Add p_align. * elf.c (assign_file_positions_for_load_sections): Set p_align to the default p_align value while laying out segments aligning to maximum page size or section alignment. (elf_is_p_align_valid): New function. (copy_elf_program_header): Call elf_is_p_align_valid to determine if p_align is valid. * elfxx-target.h (ELF_P_ALIGN): New. Default to 0. (elfNN_bed): Add ELF_P_ALIGN. * elfxx-x86.h (ELF_P_ALIGN): New. Set to ELF_MINPAGESIZE. include/ PR ld/28689 PR ld/28695 * bfdlink.h (bfd_link_info): Add maxpagesize_is_set. ld/ PR ld/28689 PR ld/28695 * emultempl/elf.em (gld${EMULATION_NAME}_handle_option): Set link_info.maxpagesize_is_set for -z max-page-size=NNN. * ldelf.c (ldelf_after_parse): Disallow link_info.commonpagesize > link_info.maxpagesize. * testsuite/ld-elf/elf.exp: Pass -z max-page-size=0x4000 to linker to build mbind2a and mbind2b. * testsuite/ld-elf/header.d: Add -z common-page-size=0x100. * testsuite/ld-elf/linux-x86.exp: Add PR ld/28689 tests. * testsuite/ld-elf/p_align-1.c: New file. * testsuite/ld-elf/page-size-1.d: New test. * testsuite/ld-elf/pr26936.d: Add -z common-page-size=0x1000. * testsuite/ld-elf/seg.d: Likewise. * testsuite/ld-scripts/rgn-at5.d: Likewise. * testsuite/ld-pru/pru_irq_map-1.d: Append 1 to name. Adjust expected PT_LOAD segment alignment. * testsuite/ld-pru/pru_irq_map-2.d: Append 2 to name. * testsuite/ld-scripts/pr23571.d: Add -z max-page-size=0x1000.
2022-01-02Update year range in copyright notice of binutils filesAlan Modra1-1/+1
The result of running etc/update-copyright.py --this-year, fixing all the files whose mode is changed by the script, plus a build with --enable-maintainer-mode --enable-cgen-maint=yes, then checking out */po/*.pot which we don't update frequently. The copy of cgen was with commit d1dd5fcc38ead reverted as that commit breaks building of bfp opcodes files.
2022-01-01ubsan: integer overflow in section filepos subtractionAlan Modra1-2/+1
* elf.c (assign_file_positions_for_non_load_sections): Avoid signed integer overflow.
2021-12-17asan: NULL dereference in bfd_elf_set_group_contentsAlan Modra1-5/+5
* elf-bfd.h (struct output_elf_obj_tdata): Make num_section_syms unsigned. * elf.c (bfd_elf_set_group_contents): Bounds check sec->index and check that entry in elf_section_syms for sec is non-NULL. (_bfd_elf_symbol_from_bfd_symbol): Adjust.
2021-12-11Don't edit bogus sh_link on reading relocatable objects (Oracle fix)Alan Modra1-34/+0
This reverts a 1995 fix to handle bogus object files. Presumably such object files have long gone. * elf.c (bfd_section_from_shdr): Remove old hack for Oracle libraries.
2021-12-10Set sh_link for reloc sections created as normal sectionsAlan Modra1-10/+16
binutils-all/strip-13 and binutils-all/strip-14 tests create SHT_REL/SHT_RELA sections by hand. These don't have sh_link set to the .symtab section as they should, leading to readelf warnings if you happen to be looking at the object files. * elf.c (assign_section_numbers): Formatting. Set sh_link for reloc sections created as normal sections in relocatable objects.
2021-12-08bfd_section_from_shdr: Support SHT_RELR sectionsFangrui Song1-3/+9
If a.so contains an SHT_RELR section, objcopy a.so will fail with: a.so: unknown type [0x13] section `.relr.dyn' This change allows objcopy to work. bfd/ * elf.c (bfd_section_from_shdr): Support SHT_RELR.
2021-11-17Fix the linker script parser so that it will recognise the PT_GNU_RELRO ↵Nick Clifton1-3/+8
segment type, and the linker itself so that it will gracefully handle being unable to assign any sections to such a segment. PR 28452 bfd * elf.c (assign_file_positions_for_non_load_sections): Replace assertion with a warning message. ld * ldgram.y: Add support for PT_GNU_RELRO and PT_GNU_PROPERTY. * ldgram.c: Regenerate.
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