Exposed by D69041. If SHT_SYMTAB does not exist, ELFObjcopy.cpp:handleArgs will crash due
to a null pointer dereference.
for (const NewSymbolInfo &SI : Config.ELF->SymbolsToAdd) {
...
Obj.SymbolTable->addSymbol(
Fix this by creating .symtab and .strtab on demand in ELFBuilder<ELFT>::readSections,
if --add-symbol is specified.
Reviewed By: grimar
Differential Revision: https://reviews.llvm.org/D69093
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@375105 91177308-0d34-0410-b5e6-96231b3b80d8
Fixes PR43181. This option was recently added to GNU objcopy (binutils
PR24942).
`llvm-objcopy -I binary -O elf64-x86-64 --set-section-alignment .data=8` can set the alignment of .data.
Reviewed By: grimar, jhenderson, rupprecht
Differential Revision: https://reviews.llvm.org/D67656
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@373461 91177308-0d34-0410-b5e6-96231b3b80d8
GNU objcopy documents that -B is only useful with architecture-less
input (i.e. "binary" or "ihex"). After D67144, -O defaults to -I, and
-B is essentially a NOP.
* If -O is binary/ihex, GNU objcopy ignores -B.
* If -O is elf*, -B provides the e_machine field in GNU objcopy.
So to convert a blob to an ELF, `-I binary -B i386:x86-64 -O elf64-x86-64` has to be specified.
`-I binary -B i386:x86-64 -O elf64-x86-64` creates an ELF with its
e_machine field set to EM_NONE in GNU objcopy, but a regular x86_64 ELF
in elftoolchain elfcopy. Follow the elftoolchain approach (ignoring -B)
to simplify code. Users that expect their command line portable should
specify -B.
Reviewed By: jhenderson
Differential Revision: https://reviews.llvm.org/D67215
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@371914 91177308-0d34-0410-b5e6-96231b3b80d8
Similar to D67254.
`struct Elf*_Shdr` has a field `sh_offset`. Rename SHOffset to SHOff to
avoid confusion.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@371281 91177308-0d34-0410-b5e6-96231b3b80d8
"Section" can refer to the type llvm::objcopy::elf::Section or the
variable name. Rename it to "Sec" for clarity. "Sec" is already used a
lot, so this change improves consistency as well.
Also change `auto` to `const SectionBase` for readability.
Reviewed By: grimar
Differential Revision: https://reviews.llvm.org/D67143
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@370852 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
GNU --strip-unneeded strips debugging sections as well. Do that for llvm-objcopy as well.
Additionally, add a test that verifies we keep the .gnu_debuglink section. This apparently was not always the case, and I'm not sure which commit fixed it, but there doesn't appear to be any test coverage to make sure we continue to do so.
This fixes PR41043.
Reviewers: jhenderson, jakehehrlich, espindola, alexshap
Subscribers: emaste, arichardson, MaskRay, abrachet, seiya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D66623
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@369761 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
The matchers for section/symbol related flags (e.g. `--keep-symbol=Name` or `--regex --keep-symbol=foo.*`) are currently just vectors that are matched linearlly. However, adding wildcard support would require negative matching too, e.g. a symbol should be removed if it matches a wildcard *but* doesn't match some other wildcard.
To make the next patch simpler, consolidate matching logic to a class defined in CopyConfig that takes care of matching.
Reviewers: jhenderson, seiya, MaskRay, espindola, alexshap
Reviewed By: jhenderson, MaskRay
Subscribers: emaste, arichardson, jakehehrlich, abrachet, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D66432
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@369689 91177308-0d34-0410-b5e6-96231b3b80d8
Now that we've moved to C++14, we no longer need the llvm::make_unique
implementation from STLExtras.h. This patch is a mechanical replacement
of (hopefully) all the llvm::make_unique instances across the monorepo.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@369013 91177308-0d34-0410-b5e6-96231b3b80d8
This reverts r365193 (git commit 194f16b3548bcb23a7f0fd638778ed72edd18d37)
This patch doesn't work with binaries built w/ `--emit-relocs`, e.g.
```
$ echo 'int main() { return 0; }' | clang -Wl,--emit-relocs -x c - -o foo && llvm-objcopy --strip-unneeded foo
llvm-objcopy: error: 'foo': not stripping symbol '__gmon_start__' because it is named in a relocation
```
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@365712 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
Use an enum instead of string to hold the output file format in Config.InputFormat and Config.OutputFormat. It's essential to support other output file formats other than ELF.
This patch originally has been submitted as D63239. However, there was an use-of-uninitialized-value bug and reverted in r364379 (git commit 4ee933c).
This patch includes the fix for the bug by setting Config.InputFormat/Config.OutputFormat in parseStripOptions.
Reviewers: espindola, alexshap, rupprecht, jhenderson
Reviewed By: jhenderson
Subscribers: emaste, arichardson, jakehehrlich, MaskRay, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D64170
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@365173 91177308-0d34-0410-b5e6-96231b3b80d8
This reverts r364254 (git commit 545f001d1b9a7b58a68d75e70bfc36c841de8999)
This change causes some llvm-obcopy tests to fail with valgrind.
Following is the output for basic-keep.test
Command Output (stderr):
--
==107406== Conditional jump or move depends on uninitialised value(s)
==107406== at 0x1A30DD: executeObjcopy(llvm::objcopy::CopyConfig const&) (llvm-objcopy.cpp:235)
==107406== by 0x1A3935: main (llvm-objcopy.cpp:294)
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@364379 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
The directive defines a symbol as an group/local memory (LDS) symbol.
LDS symbols behave similar to common symbols for the purposes of ELF,
using the processor-specific SHN_AMDGPU_LDS as section index.
It is the linker and/or runtime loader's job to "instantiate" LDS symbols
and resolve relocations that reference them.
It is not possible to initialize LDS memory (not even zero-initialize
as for .bss).
We want to be able to link together objects -- starting with relocatable
objects, but possible expanding to shared objects in the future -- that
access LDS memory in a flexible way.
LDS memory is in an address space that is entirely separate from the
address space that contains the program image (code and normal data),
so having program segments for it doesn't really make sense.
Furthermore, we want to be able to compile multiple kernels in a
compilation unit which have disjoint use of LDS memory. In that case,
we may want to place LDS symbols differently for different kernels
to save memory (LDS memory is very limited and physically private to
each kernel invocation), so we can't simply place LDS symbols in a
.lds section.
Hence this solution where LDS symbols always stay undefined.
Change-Id: I08cbc37a7c0c32f53f7b6123aa0afc91dbc1748f
Reviewers: arsenm, rampitec, t-tye, b-sumner, jsjodin
Subscribers: kzhuravl, jvesely, wdng, yaxunl, dstuttard, tpr, rupprecht, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D61493
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@364296 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
Use an enum instead of string to hold the output file format in Config.InputFormat and Config.OutputFormat. It's essential to support other output file formats other than ELF.
Reviewers: espindola, alexshap, rupprecht, jhenderson
Reviewed By: rupprecht, jhenderson
Subscribers: jyknight, compnerd, emaste, arichardson, fedor.sergeev, jakehehrlich, MaskRay, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D63239
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@364254 91177308-0d34-0410-b5e6-96231b3b80d8
Summary:
When llvm-objcopy sorts sections during finalization, it only sorts based on the offset, which can cause the group section to come after the sections it contains. This causes link failures when using gold to link objects created by llvm-objcopy.
Fix this for now by copying GNU objcopy's behavior of placing SHT_GROUP sections first. In the future, we may want to remove this sorting entirely to more closely preserve the input file layout.
This fixes https://bugs.llvm.org/show_bug.cgi?id=42052.
Reviewers: jakehehrlich, jhenderson, MaskRay, espindola, alexshap
Reviewed By: MaskRay
Subscribers: phuongtrang148993, emaste, arichardson, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D62620
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@362973 91177308-0d34-0410-b5e6-96231b3b80d8
This implements the functionality described in
https://lld.llvm.org/Partitions.html. It works as follows:
- Reads the section headers using the ELF header at file offset 0;
- If extracting a loadable partition:
- Finds the section containing the required partition ELF header by looking it up in the section table;
- Reads the ELF and program headers from the section.
- If extracting the main partition:
- Reads the ELF and program headers from file offset 0.
- Filters the section table according to which sections are in the program headers that it read:
- If ParentSegment != nullptr or section is not SHF_ALLOC, then it goes in.
- Sections containing partition ELF headers or program headers are excluded as there are no headers for these in ordinary ELF files.
Differential Revision: https://reviews.llvm.org/D62364
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@362818 91177308-0d34-0410-b5e6-96231b3b80d8
Without this, sectionWithinSegment() will return the wrong answer for bss
sections. This doesn't seem to matter now (for non-broken ELF files), but
it will matter with a change that I'm working on.
Differential Revision: https://reviews.llvm.org/D58426
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@361578 91177308-0d34-0410-b5e6-96231b3b80d8
The code in ELF/Object.cpp is sometimes a bit hard to read because of
lots of auto used everywhere. The main intention of this patch is
to replace them with the real type for places where it is not obvious.
Also it cleanups few places.
It is NFC change, but I want to be sure that there is no objections to do that since it
is massive.
DIfferential revision: https://reviews.llvm.org/D62260
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@361466 91177308-0d34-0410-b5e6-96231b3b80d8
.gnu_debuglink section contains information regarding file with
debugging symbols, identified by its CRC32. This target file is not
intended to ever change or it would invalidate the stored checksum, yet
the checksum is calculated over and over again for each of the objects
inside the archive, usually hundreds of times.
This patch precomputes the CRC32 of the target once and then reuses the
value where required, saving lots of redundant I/O.
The error message reported should stay the same, although now it might
be reported earlier.
Reviewed by: jhenderson, jakehehrlich, MaskRay
Differential Revision: https://reviews.llvm.org/D61343
Patch by Michal Janiszewski
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@360661 91177308-0d34-0410-b5e6-96231b3b80d8
GNU objcopy uses bfd_elf_get_default_section_type to decide the candidate section type,
which roughly translates to our [a] (I assume SEC_COMMON implies SHF_ALLOC):
(!(Sec.Flags & ELF::SHF_ALLOC) || Flags & (SectionFlag::SecContents | SectionFlag::SecLoad)))
Then, it updates the section type in bfd/elf.c:elf_fake_sections if:
if (this_hdr->sh_type == SHT_NULL)
this_hdr->sh_type = sh_type; // common case
else if (this_hdr->sh_type == SHT_NOBITS
&& sh_type == SHT_PROGBITS
&& (asect->flags & SEC_ALLOC) != 0) // uncommon case
...
this_hdr->sh_type = sh_type;
If the following condition is met the uncommon branch is executed:
if (elf_section_type (osec) == SHT_NULL
&& (osec->flags == isec->flags
|| (final_link
&& ((osec->flags ^ isec->flags)
& ~(SEC_LINK_ONCE | SEC_LINK_DUPLICATES | SEC_RELOC)) == 0)))
I suggest we just ignore this clause and follow the common case
behavior, which is done in this patch. Rationales to do so:
If --set-section-flags is a no-op (osec->flags == isec->flags)
(corresponds to the "readonly" test in set-section-flags.test), GNU
objcopy will require (Sec.Flags & ELF::SHF_ALLOC). [a] is essentially:
Flags & (SectionFlag::SecContents | SectionFlag::SecLoad)
This special case is not really useful. Non-SHF_ALLOC SHT_NOBITS
sections do not make much sense and it doesn't matter if they are
SHT_NOBITS or SHT_PROGBITS.
For all other RUN lines in set-section-flags.test, the new behavior
matches GNU objcopy, i.e. this patch improves compatibility.
Differential Revision: https://reviews.llvm.org/D60189
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@359639 91177308-0d34-0410-b5e6-96231b3b80d8
This is a fix for https://bugs.llvm.org/show_bug.cgi?id=41371.
Currently, it is possible to break the sh_link field of the dynamic relocation section
by removing the section it refers to. The patch fixes an issue and adds 2 test cases.
One of them shows that it does not seem possible to break the sh_info field.
I added an assert to verify this.
Differential revision: https://reviews.llvm.org/D60825
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@359552 91177308-0d34-0410-b5e6-96231b3b80d8
llvm-objcopy currently emits an error if a section to be removed is
referenced by another section. This is a reasonable thing to do, but is
different to GNU objcopy. We should allow users who know what they are
doing to have a way to produce the invalid ELF. This change adds a new
switch --allow-broken-links to both llvm-strip and llvm-objcopy to do
precisely that. The corresponding sh_link field is then set to 0 instead
of an error being emitted.
I cannot use llvm-readelf/readobj to test the link fields because they
emit an error if any sections, like the .dynsym, cannot be properly
loaded.
Reviewed by: rupprecht, grimar
Differential Revision: https://reviews.llvm.org/D60324
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@358649 91177308-0d34-0410-b5e6-96231b3b80d8
This patch fixes https://bugs.llvm.org/show_bug.cgi?id=41293 and
https://bugs.llvm.org/show_bug.cgi?id=41045. llvm-objcopy assumed that
it could always read a section header string table. This isn't the case
when the sections were previously all stripped, and the e_shstrndx field
was set to 0. This patch fixes this. It also fixes a double space in an
error message relating to this issue, and prevents llvm-objcopy from
adding extra space for non-existent section headers, meaning that
--strip-sections on the output of a previous --strip-sections run
produces identical output, simplifying the test.
Reviewed by: rupprecht, grimar
Differential Revision: https://reviews.llvm.org/D59989
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@357475 91177308-0d34-0410-b5e6-96231b3b80d8
Fangrui Song