mold is a new linker that is optimized for modern multi-core machines.
and LLVM lld, yet it is several times faster than them. Its goal is to increase
2023-11-16 21:42:17 by Frederic Cambus | Files touched by this commit (2) | |
Log message:
mold: update to 2.3.3.
mold 2.3.3 contains the following bug fixes:
- --dynamic-list has different semantics for executables and DSOs.
Previously, mold implemented only the semantics for executables, causing
issues with libraries such as musl that used this option. mold now handles
the option for DSOs correctly.
- Old object files often contain .ctors and .dtors sections, which hold
function pointers for initializing and finalizing processes, respectively.
Their roles have been superseded by .init_array and .fini_array on most
targets. mold worked functioned correctly as long as input object files
consistently use the old or the new sections. However, mixing object files
that contain both types of initializers/finalizers resulted in some
functions not being executed. This issue has been fixed.
- --defsym can cause the linker to crash if a given symbol is not defined.
The crash bug has been fixed.
- [POWER10] On rare occasions, pointers statically initialized to functions
could be left as null pointers. This bug has been fixed.
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2023-11-05 17:59:36 by Frederic Cambus | Files touched by this commit (3) | |
Log message:
mold: update to 2.3.2.
mold 2.3.0 ChangeLog:
New features:
- [x86-64] mold 2.3.0 has introduced an experimental flag, -z rewrite-endbr,
which rewrites superfluous endbr64 instructions as nop.
endbr64 is a relatively recent x86 instruction used to mark locations
where an indirect jump instruction can transfer control. With control-flow
integrity enabled (meaning endbr64 is effective), an indirect jump can
only target an endbr64 or it will trigger a runtime exception. This
mechanism significantly hinders certain control hijacking attacks, such
as ROP or JOP, since attackers cannot jump to just any location.
When given the -fcf-protection flag, GCC conservatively places an endbr64
at the beginning of every global function. This is because the function's
address might be taken as a pointer by other translation units. However,
in most cases, function addresses are not actually taken. This conservative
approach results in an overabundance of unnecessary endbr64 instructions,
leading to not only code bloating but also a potential decrease in security
as there are more locations for an attacker to exploit.
The new linker option, -z rewrite-endbr, aims to alleviate this issue.
The linker can carry out a whole-program analysis on the input files to
identify functions whose addresses are never taken. If -z rewrite-endbr
is specified, mold will conduct this analysis and replace the initial
endbr64 with a nop for functions whose addresses aren't taken.
mold also emits an endbr64 in a PLT entry only when the address of the
PLT entry is taken.
Bug fixes and compatibility improvements:
- mold now produces a more compact .gdb_index section when using the
--gdb-index flag. Additionally, mold now generates a correct .gdb_index
section for object files created by Clang.
- mold is now capable of handling input sections larger than 4 GiB.
- [PPC] mold can now generate executables for POWER10 processors. Previously,
executables produced by mold would crash immediately on startup on POWER10.
- [ARM64] When a function with a non-standard calling convention is exported,
it's mandatory for the linker to turn on the STO_AARCH64_VARIANT_PCS flag
to notify the dynamic linker. mold now appropriately sets this flag.
- [RISC-V] mold now supports new GP-relative relocations.
mold 2.3.1 contains the following bug fixes:
- [ARM32, ARM64, PowerPC, LoongArch] mold 2.3.0 would crash when handling
large output files. This was due to a bug in the code that creates range
extension thunks. This issue has now been resolved.
- [LoongArch] mold is now capable of handling relocations generated for
the -mcmodel=extreme flag.
mold 2.3.2 contains the following bug fixes:
- mold no longer emits dynamic relocations against the text segment for
GNU ifunc symbols. Previously, mold emitted such relocations for
position-dependent executables. (4cdfc7e)
- mold no longer reports the "REL-type relocation table is not supported
for this target" error and instead ignore incompatible relocation tables.
LLVM generates such non-conforming relocation tables for the
.llvm.call-graph-profile section. This change was made for compatibility.
- mold now pads unused gaps in the text segment with interrupt or NOP
instructions, instead of leaving them filled with zeros. This alteration
does not change the program's semantics but prevents disassemblers from
interpreting the spaces between functions as valid instructions.
- mold now creates the .mold-lock file for MOLD_JOBS not in the home
directory but in $XDG_RUNTIME_DIR, which is usually /var/user/<uid>.
- [ARM32] There was an issue preventing mold from being built on an ARMv8
64-bit ARM processor with an ARM32 userland, such as the 32-bit Raspberry
Pi OS running on a Raspberry Pi 4. This build issue has been resolved.
- [LoongArch] mold can now handle R_LARCH_PCALA_LO12 relocation for the
jirl instruction.
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2023-09-28 16:47:59 by Frederic Cambus | Files touched by this commit (3) | |
Log message:
mold: update to 2.2.0.
New features:
- We now use BLAKE3 as a cryptographic hash function instead of SHA256.
This change has made --build-id a few percent faster. libssl is no longer
a build dependency.
- mold is now a few percent faster than the previous version due to an
optimization of string merging code path.
- mold now emits slightly optimized code for thread-local variable accesses.
- [RISC-V] mold now supports TLSDESC relocations. TLSDESC is a new mechanism
for faster thread-local variable access. We (@ishitatsuyuki) actually led
the effort to ratify the specification (riscv-non-isa/riscv-elf-psabi-doc#373)
and implement it to compiler toolchain including GCC, GNU binutils and,
of course, mold.
Bug fixes and compatibility improvements:
- mold no longer marks an as-needed .so as "needed" if the .so file is not
directly used by the output file. Previously, mold marked a .so file as
"needed" if the .so file was used by another "needed" .so file.
- [PPC64] --execute-only now works on 64-bit PowerPC.
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2023-08-28 17:09:33 by Frederic Cambus | Files touched by this commit (4) |
Log message:
*: reset MAINTAINER to pkgsrc-users@NetBSD.org.
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2023-08-15 19:32:22 by Frederic Cambus | Files touched by this commit (3) | |
Log message:
mold: update to 2.1.0.
New features:
- Loongson's LoongArch CPU has been supported.
- -z nosectionheader has been added to eliminate section headers from the
output file.
Bug fixes and compatibility improvements:
- Previously, linking with the -z pack-relative-relocs option produces
an executable that glibc 2.38 refuses to run with DT_RELR without
GLIBC_ABI_DT_RELR dependency error. Now, mold produces binaries compatible
with glibc 2.38.
- [ARM64] R_AARCH64_ADR_PREL_PG_HI21_NC relocation type has been supported.
- [ARM64] R_AARCH64_MOVW_UABS_G3 relocation type has now been handled as a
PLT-generating relocation to fix an issue when main is not defined in the
main executable but rather in a .so file.
- [RISC-V] We now merge input .riscv.attributes contents. Previously, we
just concatenated them.
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2023-07-27 14:39:20 by Frederic Cambus | Files touched by this commit (3) | |
Log message:
mold: update to 2.0.0.
Mold 2.0.0 is a new major release of our high-speed linker. With this
release, we've transitioned our license from AGPL to MIT, aiming to expand
the user base of our linker. This was not an easy decision, as those who
have been following our progress know that we've been attempting to monetize
our product through an AGPL/commercial license dual-licensing scheme.
Unfortunately, this approach didn't meet our expectations. The license
change represents our acceptance of this reality. We don't want to persist
with a strategy that didn't work well.
In addition to the license change, here is a list of updates we have made
in this release:
- Previously, mold could not produce an object file with more than 65520
sections using the --relocatable option. Now the bug has been fixed.
- mold now interprets -undefined as a synonym for --undefined instead of
-u ndefined. This seems inconsistent, as -ufoo is generally treated as
-u foo (which is an alias for --undefined foo), but this is the behavior
of the GNU linkers and LLVM lld, so we prioritize compatibility over
consistency.
- -nopie is now handled as a synonym for --no-pie.
- [RISC-V] R_RISCV_SET_ULEB128 and R_RISCV_SUB_ULEB128 relocation types are
now supported.
- [PPC64] R_PPC64_REL32 relocation type is now supported.
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2023-07-18 16:11:18 by Nia Alarie | Files touched by this commit (35) |
Log message:
devel: Adapt packages to use USE_(CC|CXX)_FEATURES
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2023-03-17 17:33:52 by Frederic Cambus | Files touched by this commit (2) | |
Log message:
mold: update to 1.11.0.
New features:
- IBM Power10 has been supported. Previously, mold created broken
executables for that target.
- --hash-style=none has been added to cancel --hash-style=sysv,
--hash-style=gnu or --hash-style=both.
- [ARM32] R_ARM_PLT32 relocation type has been supported.
- [RISC-V] R_RISCV_PLT32 relocation type has been supported.
Bug fixes and compatibility improvements:
- Previous versions of mold failed to link some programs in rare corner
cases if Link-Time Optimization (LTO) is enabled. These bugs have been
fixed.
- mold used to ignore dependencies between DSOs. Since this version, if
a required DSO depends on other as-needed DSO, mold keeps the latter
DSO as a required one. This improves compatibility with GNU linkers.
- [x86-64] mold can now link object files generated by old buggy versions
of GCC.
- [x86-64] Previously, a program with a very large .bss section may fail
to link due to R_X86_64_REX_GOTPCRELX relocation overflow. This bug has
been fixed.
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