This works around brokenness in buildworld's bootstrapping logic: it
uses the source tree's metadata to collect dependency info (such as,
"libdwarf depends on libz") but links against static host libraries.
If these two are out of sync, as is the case if one builds a commit
prior to the introduction of the libz dependency, then the build fails
when trying to statically link nm(1).
Mitigate the problem by defining a weak uncompress() symbol which simply
returns an error. This ensures that the build won't fail when
statically linking libdwarf without zlib. The downside is that any
tools using libdwarf without zlib will now hit a runtime error if they
attempt to decode compressed sections, but at least they'll fail
deterministically, and compressed debug info is only enabled by default
in main.
In particular, this fixes building of branches lacking commit
dbf05458e3, such as releng branches, stable/12 and 13 and old
revisions of main. Previously the nm(1) build would fail with:
ld: error: undefined symbol: uncompress
>>> referenced by libdwarf_elf_init.c:233
>>> (/usr/src/contrib/elftoolchain/libdwarf/libdwarf_elf_init.c:233)
>>> libdwarf_elf_init.o:(_dwarf_elf_init) in archive
>>> /usr/lib/libdwarf.a
Reported by: dim, ler, krion
Reviewed by: imp, emaste
Fixes: dbf05458e3 ("libdwarf: Support consumption of compressed ELF sections")
MFC after: 1 week
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D33419
We were not setting "ret" before jumping to the error path, so the
function returned success even when it had failed.
Reviewed by: emaste
MFC after: 1 week
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D33420
gnu_debuglink external debug files will contain an .eh_frame section of
type SHT_NOBITS. libdwarf does not handle such sections (or rather, it
expects all debug sections to not have type SHT_NOBITS). Avoid loading
SHT_NOBITS sections, to be consistent with SGI libdwarf's handling of
this case.
PR: 239516
Diagnosed by: Paco Pascal <me@pacopascal.com>
Reviewed by: emaste (previous version)
Event: July 2020 Bugathon
MFC after: 1 week
Differential Revision: https://reviews.freebsd.org/D25626
There is no reason for diep to ever be NULL, since in that case we would
simply be leaking memory.
CID: 1418801
MFC after: 1 week
Sponsored by: The FreeBSD Foundation
All callers pass a non-NULL pointer, and otherwise it was possible to
leak memory if the abbrev was not added to a CU.
CID: 1193365
MFC after: 1 week
Sponsored by: The FreeBSD Foundation
All callers of _dwarf_add_expr() and _dwarf_expr_into_block() pass a
non-NULL expr pointer, and these functions assume that expr is non-NULL
anyway.
CID: 1193305, 1193306
MFC after: 1 week
Sponsored by: The FreeBSD Foundation
Previously we would perform a linear search of the DWARF section
list for ".debug_str". However, libdwarf always caches a pointer to
the strtab image in its debug descriptor. Using it gives a modest
performance improvement when iterating over the attributes of each
DIE.
Reviewed by: emaste
MFC after: 1 week
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D20759
Summary:
Due to missing relocation support in libdwarf for powerpc64, handling of dwarf
info on unlinked objects was bogus.
Examining raw dwarf data on objects compiled on ppc64 with a modern compiler
(in-tree gcc tends to hide the issue, since it only rarely generates relocations
in .debug_info and uses DW_FORM_str instead of DW_FORM_strp for everything), you
will find that the dwarf data appears corrupt, with repeated references to the
compiler version where things like types and function names should appear.
This happens because the 0 offset of .debug_str contains the compiler version,
and without applying the relocations, *all* indirect strings in .dwarf_info will
end up pointing to it.
This corruption then propogates to the CTF data, as ctfconvert relies on
libdwarf to read the dwarf info, for every compiled object (when building a
kernel.)
However, if you examine the dwarf data on a compiled executable, it will appear
correct, because during final link the relocations get applied and baked in by
the linker.
Submitted by: Brandon Bergren
Reviewed By: emaste
Differential Revision: https://reviews.freebsd.org/D20367
Relative directories may appear in the line number program for a CPU if
files were included via a relative path, for instance with "-I.".
Previously, dwarf_srclines(3) and dwarf_srcfiles(3) would return the
relative path, so addr2line, for instance, would do the same. However,
we can get an absolute path by prepending the compilation directory, so
change libdwarf to do that to improve compatibility with GNU binutils
and since it is more useful in general.
Reviewed by: jhb
Discussed with: emaste
MFC after: 2 weeks
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D19705
Highlights:
- Make sure that only TLS sections are sorted into TLS segment.
- Fixed multiple errors in "Section to Segment mapping".
- Man page updates
- ar improvements
- elfcopy: avoid filter_reloc uninitialized variable for rela
- elfcopy: avoid stripping relocations from static binaries
- readelf: avoid printing directory in front of absolute path
- readelf: add NT_FREEBSD_FEATURE_CTL FreeBSD note type
- test improvements
NOTES:
Some of these changes originated in FreeBSD and simply reduce diffs
between contrib and vendor.
ELF Tool Chain ar is not (currently) used in FreeBSD, and there are
improvements in both FreeBSD and ELF Tool Chain ar that are not in
the other.
Sponsored by: The FreeBSD Foundation
Highlights of changes between r3490 and r3520:
- Improve C++ demangling
- Improve compatibility with Binutils tools wrt. error messages
- Handle additional types/sections/etc. in readelf and elfdump
- addr2line, cxxfilt: use setvbuf to set line buffering for filter use
PR: 218395
MFC after: 2 weeks
Relnotes: Yes
Sponsored by: The FreeBSD Foundation
dwarf_attrval_*() will search the parent DIE referenced by a
DW_AT_abstract_origin attribute for the value of the DW_AT_type attribute.
Do the same thing for the DW_AT_specification attributes in variable
definitions emitted by GCC 6.2, and ensure that we return an error rather
than crashing if neither DW_AT_abstract_origin or DW_AT_specification is
found when looking for the value of the DW_AT_type attribute.
PR: 215350, 215395
Reviewed by: emaste
MFC after: 2 weeks
Differential Revision: https://reviews.freebsd.org/D8920
This fixes build failures on older releases that lack various
definitions such as EM_AARCH64 (which was unfixed before this).
Revert all of the recent compatibility changes that worked around this
problem.
This uses the same method of using the in-tree header as lib/libelf,
lib/libdwarf and usr.bin/readelf.
Reviewed by: emaste
Sponsored by: EMC / Isilon Storage Division
Differential Revision: https://reviews.freebsd.org/D6734
Improvements include:
* Add support for reporting and handling a number of new constants in
various tools, including:
* CloudABI OSABI
* DT_TLSDESC_*
* i386, MIPS, SPARC and amd64 relocations
* C++ demangler bug fixes
* Man page updates
* Improved input validation in several tools
This update also reduces diffs against upstream as a number of fixes
included in upstream were previously cherry-picked into FreeBSD.
Sponsored by: The FreeBSD Foundation
Some notable improvements include:
readelf:
- Add AArch64 relocation definitions.
- Report value of unknown relocation types.
elfcopy:
- Consider symbols with STB_GNU_UNIQUE binding as global symbols.
- Fixed support for VMA adjustment for loadable sections found
in relocatable objects.
- Handle nameless global symbols.
- Improve wildcard matching for !-prefixed symbols.
- Add PE/COFF support.
elfdump:
- Improve section type reporting.
- Add MIPS-specific section types.
This update also includes a significant number of bug fixes.
PR: 207091 [exp-run]
Sponsored by: The FreeBSD Foundation
Highlights (not already in the FreeBSD tree):
- addr2line: Fixed multiple memory leaks related to DIE allocation
- readelf: improve sh_link validation
- various man page improvements
Sponsored by: The FreeBSD Foundation
Highlights (upstream revisions):
- Fix SHT_GROUP handling in elfcopy/strip (3206 3220 3221)
- Misc elfcopy / strip bug fixes (3215 3216 3217)
- Many C++ demangler improvements (3199 3200 3201 3202 3203 3204 3205
3208 3210 3211 3212)
- Improve GNU binutils compatibility in elfcopy / strip (3213 3214)
- Add -g option to readelf(1): dump contents of section groups (3219)
- Add EM_IAMCU 32-bit Intel MCU (3198)
Also add a compat #define for building with older FreeBSD ELF headers.
The GRP_COMDAT flag was added to elf_common.h in r283110, but it's not
available during the bootstrap build. It is also convenient to be able
to build on older hosts.
Thanks to antoine@ for tracking down issues through multiple exp-runs
and to kaiw@ for fixing.
PR: 198611 (exp-run), 200350
Sponsored by: The FreeBSD Foundation
Highlights:
- Fix man page markup, whitespace, and typos
- Fix sh_info of SHT_GROUP section to point to the correct string
- Improve validation in readelf and elfcopy/strip
- Handle DWARF 4's DW_AT_high_pc in addr2line
Sponsored by: The FreeBSD Foundation
Some architectures use .rel relocations (for debug data), so they must
be handled.
This was discovered from ctfconvert on ARM object files. The lack of
relocation handling caused all string lookups to return the string at
offset 0 in .debug_str, typically "FreeBSD clang version ..."
Reviewed by: gnn, imp, rpaulo (earlier version)
Sponsored by: The FreeBSD Foundation
Differential Revision: https://reviews.freebsd.org/D1819
This fixes two strip(1) issues found during ports exp-run and adds a
string hash implementation which significantly speeds up certain
operations on objects with large numbers of symbols.
This also improves libdwarf handling for stripped objects with
.eh_frame or .debug_frame (but not other debug) sections.
PR: 196107
Sponsored by: The FreeBSD Foundation
This includes a number of libdwarf improvements (particularly DWARF4
related) and updates to elftoolchain tools such as strip(1). It also
includes a large number of miscellaneous fixes (memory leaks, sign and
cast warnings, integer overflow and underflow, etc.).
This is a merge of r276167,276170-276172 from the
projects/elftoolchain-update-r3130 branch.
Sponsored by: The FreeBSD Foundation
attributes that have form DW_FORM_sec_offset.
* If the .debug_info section conforms to DWARF4, do not allow the value
of attributes with form DW_FORM_data[48] to be used as section
offset.
(DWARF4) form DW_FORM_flag_present which implicitly indicates the
presence of the attribute. Manual page is updated to reflect this
change.
Note that this was previously fixed in the old libdwarf.
