34 Commits

Author SHA1 Message Date
quic-akaryaki
535520c663
[llvm-objcopy] --gap-fill and 0-size sections (#75837)
In the change that added `--gap-fill`, the condition to choose the
sections to write in `BinaryWriter::write()` did not exclude zero-size
sections. However, zero-size sections did not have correct offsets
assigned in `BinaryWriter::finalize()`. The result is either a failed
assertion, or memory corruption due to writing to the buffer beyond its
size.
To fix this, exclude zero-size sections from writing. Also, add a zero-size
section to the test, which would trigger the problem.
2023-12-19 15:30:29 -06:00
quic-akaryaki
4070dffd34
[llvm-objcopy] Add --gap-fill and --pad-to options (#65815)
`--gap-fill <value>` fills the gaps between sections with a specified
8-bit value, instead of zero.
`--pad-to <address>` pads the output binary up to the specified load
address, using the 8-bit value from `--gap-fill` or zero.

These options are only supported for ELF input and binary output.
2023-12-14 16:28:34 -06:00
Kazu Hirata
4a0ccfa865 Use llvm::endianness::{big,little,native} (NFC)
Note that llvm::support::endianness has been renamed to
llvm::endianness while becoming an enum class as opposed to an
enum. This patch replaces support::{big,little,native} with
llvm::endianness::{big,little,native}.
2023-10-12 21:21:45 -07:00
Gregory Alfonso
40dc8e6889 [NFC] Use const references to avoid copying objects in for-loops
Differential Revision: https://reviews.llvm.org/D139487
2023-09-27 13:39:30 -07:00
Alexey Karyakin
c973123fdc [llvm-objcopy] -O binary: do not align physical addresses
llvm-objcopy should not insert padding before a section if its
physical addresses is not aligned to section's alignment. This
behavior will match GNU objcopy and is important for embedded images
where the physical address is used to store the initial data image.
The loader typically will copy this image using a start symbol
created by the linker. If llvm-objcopy inserts padding before such a
section, the symbol address will not match the location in the image.

This commit refines the change in https://reviews.llvm.org/D128961
which intended to align sections which type changed from NOBITS and
their offset may not be aligned. However, it affected all sections.

Fix https://github.com/llvm/llvm-project/issues/62636

Reviewed By: jhenderson, MaskRay

Differential Revision: https://reviews.llvm.org/D150276
2023-06-20 15:45:33 -07:00
Krzysztof Parzyszek
ebc757d3b6 Revert "[llvm-objcopy] -O binary: do not align physical addresses"
This reverts commit eb1442d0f73c76cfb5051d133f858fe760d189cf.

The test tools/llvm-objcopy/ELF/binary-paddr.test fails on
ppc64be-clang-test-suite:
https://lab.llvm.org/buildbot#builders/231/builds/13120

Reverting at author's request.
2023-06-20 14:46:55 -07:00
Alexey Karyakin
eb1442d0f7 [llvm-objcopy] -O binary: do not align physical addresses
llvm-objcopy should not insert padding before a section if its
physical addresses is not aligned to section's alignment. This
behavior will match GNU objcopy and is important for embedded images
where the physical address is used to store the initial data image.
The loader typically will copy this image using a start symbol
created by the linker. If llvm-objcopy inserts padding before such a
section, the symbol address will not match the location in the image.

This commit refines the change in https://reviews.llvm.org/D128961
which intended to align sections which type changed from NOBITS and
their offset may not be aligned. However, it affected all sections.

Fix https://github.com/llvm/llvm-project/issues/62636

Reviewed By: jhenderson, MaskRay

Differential Revision: https://reviews.llvm.org/D150276
2023-06-20 13:28:40 -07:00
David Blaikie
f3df0cf3b0 Remove unnecessary copy 2023-06-07 18:02:58 +00:00
Andrew Ng
744e589caa [llvm-objcopy][ELF] Preserve sh_link to .symtab when applicable
This change to llvm-objcopy preserves the ELF section sh_link to .symtab
so long as none of the symbol table indices have been changed.
Previously, any invocation of llvm-objcopy including a "no-op" would
clear any section sh_link to .symtab.

Differential Revision: https://reviews.llvm.org/D150859
2023-06-06 14:35:04 +01:00
Moshe Berman
bc6e10c9ef [ELF][llvm-objcopy] Reject duplicate SHT_SYMTAB sections
The gABI prohibits multiple SH_SYMTAB sections. As a result,
llvm-objcopy was crashing in SymbolTableSection::removeSymbols(). This
patch fixes the issue by emitting an error if multiple SH_SYMTAB
sections are encountered when building an ELF object.

Fixes: https://github.com/llvm/llvm-project/issues/60448

Differential Revision: https://reviews.llvm.org/D143508
2023-02-17 17:59:20 +00:00
David Spickett
beae6bfa14 [LLVM][objcopy] Fix update-section.test on 32 bit platforms
This used %zu to print a uint64_t type. z is for size_t so on 32 bit
we tried to treat it as a 32 bit number.

Use PRIu64 instead to print as 64 bit everywhere.
2022-12-16 11:12:15 +00:00
Fangrui Song
ec941432cf [ObjCopy] llvm::Optional => std::optional 2022-12-10 19:46:02 +00:00
Fangrui Song
e18b7c7ae0 [llvm-objcopy] Support --decompress-debug-sections when zlib is disabled
When zlib is disabled at build time, the diagnostic `LLVM was not compiled with
LLVM_ENABLE_ZLIB: cannot decompress` for --decompress-debug-sections may be
inaccurate: if zstd is enabled, we should still support zstd decompression.

It's not useful to test zlib and zstd. Just remove the diagnostic and add a new
one before `compression::decompress`.

This fixes compress-debug-sections-zstd.test

Reviewed By: mariusz-sikora-at-amd, jhenderson, phosek

Differential Revision: https://reviews.llvm.org/D135744
2022-10-12 11:52:05 -07:00
Fangrui Song
c997fe6586 [llvm-objcopy] --compress-debug-sections: remove tail padding for ELFCLASS32
For an ELFCLASS32 object, a compressed section due to --compress-debug-sections={zlib,zstd} has a
tail padding of 12 zero bytes. zlib happily allows this while zstd is rigid and
reports `error: '{{.*}}': failed to decompress section '.debug_foo': Src size is incorrect`.

Cole Kissane reported the problem.

Reviewed By: jhenderson, phosek

Differential Revision: https://reviews.llvm.org/D134385
2022-09-22 10:26:47 -07:00
Fangrui Song
781dea021a [Support] Rename DebugCompressionType::Z to Zlib
"Z" was so named when we had both gABI ELFCOMPRESS_ZLIB and the legacy .zdebug support.
Now we have just one zlib format, we should use the more descriptive name.
2022-09-08 16:11:29 -07:00
Fangrui Song
b6e1fd761d [llvm-objcopy] Support --{,de}compress-debug-sections for zstd
Also, add ELFCOMPRESS_ZSTD (2) from the approved generic-abi proposal:
https://groups.google.com/g/generic-abi/c/satyPkuMisk
("Add new ch_type value: ELFCOMPRESS_ZSTD")

Link: https://discourse.llvm.org/t/rfc-zstandard-as-a-second-compression-method-to-llvm/63399
("[RFC] Zstandard as a second compression method to LLVM")

Reviewed By: jhenderson, dblaikie

Differential Revision: https://reviews.llvm.org/D130458
2022-09-08 00:59:14 -07:00
Nikita Popov
0444b40ed3 Revert "[Support] Add llvm::compression::{getReasonIfUnsupported,compress,decompress}"
This reverts commit 19dc3cff0f771bb8933136ef68e782553e920d04.
This reverts commit 5b19a1f8e88da9ec92b995bfee90043795c2c252.
This reverts commit 9397648ac8ad192f7e6e6a8e6894c27bf7e024e9.
This reverts commit 10842b44759f987777b08e7714ef77da2526473a.

Breaks the GCC build, as reported here:
https://reviews.llvm.org/D130506#3776415
2022-09-08 09:33:12 +02:00
Fangrui Song
5b19a1f8e8 [llvm-objcopy] Support --{,de}compress-debug-sections for zstd
Also, add ELFCOMPRESS_ZSTD (2) from the approved generic-abi proposal:
https://groups.google.com/g/generic-abi/c/satyPkuMisk
("Add new ch_type value: ELFCOMPRESS_ZSTD")

Link: https://discourse.llvm.org/t/rfc-zstandard-as-a-second-compression-method-to-llvm/63399
("[RFC] Zstandard as a second compression method to LLVM")

Reviewed By: jhenderson, dblaikie

Differential Revision: https://reviews.llvm.org/D130458
2022-09-07 23:53:40 -07:00
Fangrui Song
ce6dd4e835 Revert D130458 "[llvm-objcopy] Support --{,de}compress-debug-sections for zstd"
This reverts commit c26dc2904b95b3685d883e760e84046ea6c33d7f.

The new Zstd dispatch has an ongoing design discussion related to https://reviews.llvm.org/D130516#3688123 .
Revert for now before it is resolved.
2022-07-29 15:46:51 -07:00
Fangrui Song
c26dc2904b [llvm-objcopy] Support --{,de}compress-debug-sections for zstd
Also, add ELFCOMPRESS_ZSTD (2) from the approved generic-abi proposal:
https://groups.google.com/g/generic-abi/c/satyPkuMisk
("Add new ch_type value: ELFCOMPRESS_ZSTD")

Link: https://discourse.llvm.org/t/rfc-zstandard-as-a-second-compression-method-to-llvm/63399
("[RFC] Zstandard as a second compression method to LLVM")

Differential Revision: https://reviews.llvm.org/D130458
2022-07-28 10:45:53 -07:00
Fangrui Song
91e2cd4fa9 [llvm-objcopy] Remove getDecompressedSizeAndAlignment. NFC 2022-07-25 00:06:36 -07:00
Fangrui Song
7181c4e10a [llvm-objcopy] --compress-debug-sections: fix uninitialized ch_reserved for Elf64_Chdr
ch_reserved is uninitialized and the output is not deterministic. Fix it.
Rewrite and improve compress-debug-sections-zlib.test.
2022-07-24 22:19:00 -07:00
Fangrui Song
73c84f9c13 [llvm-objcopy] Remove remnant .zdebug code 2022-07-24 18:52:15 -07:00
Fangrui Song
6977ff4006 [MC] Delete dead zlib-gnu code and simplify writeSectionData 2022-07-24 01:17:34 -07:00
Fangrui Song
e690137dde [Support] Change compression::zlib::{compress,uncompress} to use uint8_t *
It's more natural to use uint8_t * (std::byte needs C++17 and llvm has
too much uint8_t *) and most callers use uint8_t * instead of char *.
The functions are recently moved into `llvm::compression::zlib::`, so
downstream projects need to make adaption anyway.
2022-07-13 16:26:54 -07:00
Cole Kissane
ea61750c35 [NFC] Refactor llvm::zlib namespace
* Refactor compression namespaces across the project, making way for a possible
  introduction of alternatives to zlib compression.
  Changes are as follows:
  * Relocate the `llvm::zlib` namespace to `llvm::compression::zlib`.

Reviewed By: MaskRay, leonardchan, phosek

Differential Revision: https://reviews.llvm.org/D128953
2022-07-08 11:19:07 -07:00
Fangrui Song
0c01f42fad [llvm-objcopy] -O binary: align sh_offset for section changed from SHT_NOBITS
For a SHT_NOBITS section like .bss, its sh_offset is typically not
aligned by sh_addralign. If it is converted to SHT_PROGBITS by
`--set-section-flags .bss=alloc,contents`, we should conceptually align
it when computing the output size for -O binary. Otherwise the output
size may be smaller than GNU objcopy produced output.

* binary-no-paddr.test has a case with non-sensical p_paddr=1 which has
  a changed behavior. Update it.

Close https://github.com/llvm/llvm-project/issues/55246

Reviewed By: jhenderson

Differential Revision: https://reviews.llvm.org/D128961
2022-07-04 21:45:19 -07:00
Fangrui Song
45ae553109 [llvm-objcopy] Remove support for legacy .zdebug sections
clang 14 removed -gz=zlib-gnu support and ld.lld removed linker input support
for zlib-gnu in D126793. Now let's remove zlib-gnu from llvm-objcopy.

* .zdebug* sections are no longer recognized as debug sections. --strip* don't remove them.
  They are copied like other opaque sections
* --decompress-debug-sections does not uncompress .zdebug* sections
* --compress-debug-sections=zlib-gnu is not supported

It is very rare but in case a user has object files using .zdebug . They can use
llvm-objcopy<15 or GNU objcopy for uncompression.
--compress-debug-sections=zlib-gnu is unlikely ever used by anyone, so I do not
add a custom diagnostic.

Differential Revision: https://reviews.llvm.org/D128688
2022-06-29 10:42:55 -07:00
Kazu Hirata
3b9707dbc0 [llvm] Convert for_each to range-based for loops (NFC) 2022-06-05 12:07:14 -07:00
Anubhab Ghosh
9da89651a8 [llvm-objcopy][ObjectYAML][mips] Add MIPS specific ELF section indexes
This fixes https://github.com/llvm/llvm-project/issues/53998
and displays correct information in obj2yaml for SHN_MIPS_*
sections according to
https://refspecs.linuxfoundation.org/elf/mipsabi.pdf

Reviewed By: jhenderson, MaskRay

Differential Revision: https://reviews.llvm.org/D123902
2022-05-25 09:01:12 -07:00
Kazu Hirata
c008e92b33 Apply clang-tidy fixes for modernize-use-equals-default in ELFObject.cpp (NFC) 2022-03-28 09:18:25 -07:00
Fangrui Song
cce3521020 [llvm-objcopy] Simplify CompressedSection creation. NFC
Remove Expected<CompressedSection> factory functions in favor of constructors
now that zlib::compress returns void (D121512).

Reviewed By: jhenderson

Differential Revision: https://reviews.llvm.org/D121644
2022-03-14 23:15:15 -07:00
Fangrui Song
407c721ceb [Support] Change zlib::compress to return void
With a sufficiently large output buffer, the only failure is Z_MEM_ERROR.
Check it and call the noreturn report_bad_alloc_error if applicable.
resize_for_overwrite may call report_bad_alloc_error as well.

Now that there is no other error type, we can replace the return type with void
and simplify call sites.

Reviewed By: ikudrin

Differential Revision: https://reviews.llvm.org/D121512
2022-03-14 11:38:04 -07:00
Alexey Lapshin
25d7b4fb44 [objcopy][NFC] Rename files to avoid clashing of archive members.
libtool uses file names to name members of an static library.
Files, located in different directories and having matching name,
would have the same name inside an archive. This is not a problem
for ld, but may be a problem for ar. This patch renames files
from ObjCopy library to avoid names clashing.

See https://reviews.llvm.org/D88827#3335814

Differential Revision: https://reviews.llvm.org/D120345
2022-02-23 13:05:39 +03:00