**Context:**
This is a second attempt at introducing signature regeneration to llvm-objcopy. In this diff: https://reviews.llvm.org/D109840, a script was introduced to test
the validity of a code signature. In this diff: https://reviews.llvm.org/D109803 (now reverted), an effort was made to extract the signature generation behavior out of LLD into a common location for use in llvm-objcopy. In this diff: https://reviews.llvm.org/D109972 it was decided that there was no appropriate common location and that a small amount of duplication to bring signature generation to llvm-objcopy would be better. This diff introduces this duplication.
**Summary**
Prior to this change, if a LC_CODE_SIGNATURE load command
was included in the binary passed to llvm-objcopy, the command and
associated section were simply copied and included verbatim in the
new binary. If rest of the binary was modified at all, this results
in an invalid Mach-O file. This change regenerates the signature
rather than copying it.
The code_signature_lc.test test was modified to include the yaml
representation of a small signed MachO executable in order to
effectively test the signature generation.
Reviewed By: alexander-shaposhnikov, #lld-macho
Differential Revision: https://reviews.llvm.org/D111164
The load command is currently specific to arm64 and holds information
for instruction rewriting, e.g. converting a GOT load to an ADR to
compute a local address.
(On ELF the information is usually conveyed by relocations, e.g.
R_X86_64_REX_GOTPCRELX, R_PPC64_TOC16_HA)
Reviewed By: alexander-shaposhnikov
Differential Revision: https://reviews.llvm.org/D104968
An ARM64_RELOC_ADDEND relocation reuses the symbol field for the addend value.
We should pass through such relocations.
Reviewed By: alexander-shaposhnikov
Differential Revision: https://reviews.llvm.org/D104967
During D88827 it was requested to remove the local implementation
of Memory/File Buffers:
// TODO: refactor the buffer classes in LLVM to enable us to use them here
// directly.
This patch uses raw_ostream instead of Buffers. Generally, using streams
could allow us to reduce memory usages. No need to load all data into the
memory - the data could be streamed through a smaller buffer.
Thus, this patch uses raw_ostream as an interface for output data:
Error executeObjcopyOnBinary(CopyConfig &Config,
object::Binary &In,
raw_ostream &Out);
Note 1. This patch does not change the implementation of Writers
so that data would be directly stored into raw_ostream.
This is assumed to be done later.
Note 2. It would be better if Writers would be implemented in a such way
that data could be streamed without seeking/updating. If that would be
inconvenient then raw_ostream could be replaced with raw_pwrite_stream
to have a possibility to seek back and update file headers.
This is assumed to be done later if necessary.
Note 3. Current FileOutputBuffer allows using a memory-mapped file.
The raw_fd_ostream (which could be used if data should be stored in the file)
does not allow us to use a memory-mapped file. Memory map functionality
could be implemented for raw_fd_ostream:
It is possible to add resize() method into raw_ostream.
class raw_ostream {
void resize(uint64_t size);
}
That method, implemented for raw_fd_ostream, could create a memory-mapped file.
The streamed data would be written into that memory file then.
Thus we would be able to use memory-mapped files with raw_fd_ostream.
This is assumed to be done later if necessary.
Differential Revision: https://reviews.llvm.org/D91028
Some binaries can contain regular sections with zero offset and zero size.
This diff makes llvm-objcopy's handling of such sections consistent with
cctools's strip (which doesn't modify them),
previously the tool would allocate file space for them.
Test plan: make check-all
Differential revision: https://reviews.llvm.org/D90796
Virtual sections do not contribute to the final output size.
This diff fixes the corresponding calculations in the method MachOWriter::totalSize.
Test plan: make check-all
Differential revision: https://reviews.llvm.org/D89661
This diff adds support for copying binaries
containing a LC_CODE_SIGNATURE load command.
Test plan: make check-all
Differential revision: https://reviews.llvm.org/D81768
Fix handling of relocations with r_extern == 0.
If r_extern == 0 then r_symbolnum is an index of a section rather than a symbol index.
Patch by Seiya Nuta and Alexander Shaposhnikov.
Test plan: make check-all
Differential revision: https://reviews.llvm.org/D78946
The header magic value is held in the native endianness, so the method used in
cc0ec3fdb9. Use MachOReader / MachOWriter's existing endianness tests instead.
Use shift/mask operations to access r_symbolnum rather than relying on
MachO::relocation_info. This should fix the big-endian bot failures that were
caused by 386f1c114d.
In this diff we change the storage of a section to unique_ptr.
This refactoring was factored out from D71647.
Test plan: make check-all
Differential revision: https://reviews.llvm.org/D74946
This diff adds a new "driver" for llvm-objcopy
which is supposed to emulate the behavior of install-name-tool.
This is a recommit of b5913e6 with ubsan, test dependencies issues fixed.
Differential revision: https://reviews.llvm.org/D69146
Test plan: make check-all
This diff adds a new "driver" for llvm-objcopy
which is supposed to emulate the behavior of install-name-tool.
This is a recommit of b5913e6d2 with ubsan issues fixed.
Differential revision: https://reviews.llvm.org/D69146
Test plan: make check-all
Summary:
Parse the indirect symbol table and update the indexes of
symbol entries in the table in the writer in case they have
been changed.
Reviewers: alexshap, rupprecht, jhenderson
Reviewed By: alexshap, rupprecht
Subscribers: jakehehrlich, abrachet, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D66280
Summary:
This patch implements copying some load commands that appear in executables/shared libraries such as the indirect symbol table.
I don't add tests intentionally because this patch is incomplete: we need a layout algorithm for executables/shared libraries. I'll submit it as a separate patch with tests.
Reviewers: alexshap, rupprecht, jhenderson, compnerd
Reviewed By: alexshap
Subscribers: abrachet, mgorny, mgrang, MaskRay, mtrent, jakehehrlich, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D63395
llvm-svn: 369298
Summary:
This patch implements copying some load commands that appear in executables/shared libraries such as the indirect symbol table.
I don't add tests intentionally because this patch is incomplete: we need a layout algorithm for executables/shared libraries. I'll submit it as a separate patch with tests.
Reviewers: alexshap, rupprecht, jhenderson, compnerd
Reviewed By: alexshap
Subscribers: abrachet, mgorny, mgrang, MaskRay, mtrent, jakehehrlich, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D63395
llvm-svn: 369230
Summary: Build the string table using StringTableBuilder, reassign symbol indices, and update symbol indices in relocations to allow adding/modifying/removing symbols from the object.
Reviewers: alexshap, rupprecht, jhenderson
Reviewed By: alexshap
Subscribers: mgorny, jakehehrlich, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D63309
llvm-svn: 364000
Summary:
Recompute and update offset/size fields so that we can implement llvm-objcopy options like --only-section.
This patch is the first step and focuses on supporting load commands that covered by existing tests: executable files and
dynamic libraries are not supported.
Reviewers: alexshap, rupprecht, jhenderson
Reviewed By: alexshap, rupprecht
Subscribers: compnerd, jakehehrlich, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D62652
llvm-svn: 362863
This diff implements first bits for copying (without modification) MachO object files.
Test plan: make check-all
Differential revision: https://reviews.llvm.org/D54674
llvm-svn: 352944
Keith Smiley