This function can really fail since the string table offset can be out of
bounds.
Using ErrorOr makes sure the error is checked.
Hopefully a lot of the boilerplate code in tools/* can go away once we have
a diagnostic manager in Object.
llvm-svn: 241297
Realistically, this will be returning ErrorOr for some time as refactoring the
user code to check once per section will take some time.
Given that, use it for checking if a relocation has addend or not.
While at it, add ELFRelocationRef to simplify the users.
llvm-svn: 241028
This is still a really odd function. Most calls are in object format specific
contexts and should probably be replaced with a more direct query, but at least
now this is not too obnoxious to use.
llvm-svn: 240777
So far, LLVM has not emitted correct addend for N64 and N32 ABI. This patch
fixes that. It also removes fixup from MCJIT for R_MIPS_PC16 relocation.
Patch by Vladimir Radosavljevic.
Differential Revision: http://reviews.llvm.org/D10565
llvm-svn: 240404
This patch changes getRelocationAddend to use ErrorOr and considers it an error
to try to get the addend of a REL section.
If, for example, a x86_64 file has a REL section, that file is corrupted and
we should reject it.
Using ErrorOr is not ideal since we check the section type once per relocation
instead of once per section.
Checking once per section would involve getRelocationAddend just asserting and
callers checking the section before iterating over the relocations.
In any case, this is an improvement and includes a test.
llvm-svn: 240176
fix segfault by checking for UnknownArch, since
getArchTypePrefix() will return nullptr for UnknownArch.
This fixes regression caused by r238424.
llvm-svn: 239456
This patch adds R_MIPS_PC32 relocation for Mips64.
Patch by Vladimir Radosavljevic.
Differential Revision: http://reviews.llvm.org/D10235
llvm-svn: 239301
The windows buildbot originally failed because the check expressions are
evaluated as 64-bit values, even for 32-bit symbols. Fixed this by comparing
bottom 32-bits of the expressions.
The host/target endian mismatch issue is that it's invalid to read/write target
values using a host pointer without taking care of endian differences between
the target and host. Most (if not all) instances of
reinterpret_cast<uint32_t*>() in the RuntimeDyld are examples of this bug.
This has been fixed for Mips using the endian aware read/write functions.
The original commits were:
r238838:
[mips] Add RuntimeDyld tests for currently supported O32 relocations.
Reviewers: petarj, vkalintiris
Reviewed By: vkalintiris
Subscribers: vkalintiris, llvm-commits
Differential Revision: http://reviews.llvm.org/D10126
r238844:
[mips][mcjit] Add support for R_MIPS_PC32.
Summary:
This allows us to resolve relocations for DW_EH_PE_pcrel TType encodings
in the exception handling LSDA.
Also fixed a nearby typo.
Reviewers: petarj, vkalintiris
Reviewed By: vkalintiris
Subscribers: vkalintiris, llvm-commits
Differential Revision: http://reviews.llvm.org/D10127
llvm-svn: 238915
Summary:
This allows us to resolve relocations for DW_EH_PE_pcrel TType encodings
in the exception handling LSDA.
Also fixed a nearby typo.
Reviewers: petarj, vkalintiris
Reviewed By: vkalintiris
Subscribers: vkalintiris, llvm-commits
Differential Revision: http://reviews.llvm.org/D10127
llvm-svn: 238844
Add support for resolving MIPS64r2 and MIPS64r6 relocations in MCJIT.
Patch by Vladimir Radosavljevic.
Differential Revision: http://reviews.llvm.org/D9667
llvm-svn: 238424
Summary:
This supersedes http://reviews.llvm.org/D4010, hopefully properly
dealing with the JIT case and also adds an actual test case.
DwarfContext was basically already usable for the JIT (and back when
we were overwriting ELF files it actually worked out of the box by
accident), but in order to resolve relocations correctly it needs
to know the load address of the section.
Rather than trying to get this out of the ObjectFile or requiring
the user to create a new ObjectFile just to get some debug info,
this adds the capability to pass in that info directly.
As part of this I separated out part of the LoadedObjectInfo struct
from RuntimeDyld, since it is now required at a higher layer.
Reviewers: lhames, echristo
Reviewed By: echristo
Subscribers: vtjnash, friss, rafael, llvm-commits
Differential Revision: http://reviews.llvm.org/D6961
llvm-svn: 237961
isInt is a little easier to read, let's use that more consistently.
Incidentally, this also silences a warning for shifting a negative
number.
This fixes PR23532.
llvm-svn: 237476
This reapplies r235060 and 235070, which were reverted because of test failures
in LLDB. The failure was caused because at moment RuntimeDyld is processing
relocations for all sections, irrespective of whether we actually load them
into memory or not, but RuntimeDyld was not actually remembering where in memory
the unrelocated section is. This commit includes a fix for that issue by
remembering that pointer, though the longer term fix should be to stop processing
unneeded sections.
Original Summary:
This allows us to get rid of the original unrelocated object file after
we're done processing relocations (but before applying them).
MachO and COFF already do not require this (currently we have temporary hacks
to prevent ownership from being released, but those are brittle and should be
removed soon).
The placeholder mechanism allowed the relocation resolver to look at original
object file to obtain more information that are required to apply the
relocations. This is usually necessary in two cases:
- For relocations targetting sub-word memory locations, there may be pieces
of the instruction at the target address which we should not override.
- Some relocations on some platforms allow an extra addend to be encoded in
their immediate fields.
The problem is that in the second case the information cannot be recovered
after the relocations have been applied once because they will have been
overridden. In the first case we also need to be careful to not use any bits
that aren't fixed and may have been overriden by applying a first relocation.
In the past both have been fixed by just looking at original object file. This
patch attempts to recover the information from the first by looking at the
relocated object file, while the extra addend in the second case is read
upon relocation processing and addend to the regular addend.
I have tested this on X86. Other platforms represent my best understanding
of how those relocations should work, but I may have missed something because
I do not have access to those platforms.
We will keep the ugly workarounds in place for a couple of days, so this commit
can be reverted if it breaks the bots.
Differential Revision: http://reviews.llvm.org/D9028
llvm-svn: 236341
Summary:
This allows us to get rid of the original unrelocated object file after
we're done processing relocations (but before applying them).
MachO and COFF already do not require this (currently we have temporary hacks
to prevent ownership from being released, but those are brittle and should be
removed soon).
The placeholder mechanism allowed the relocation resolver to look at original
object file to obtain more information that are required to apply the
relocations. This is usually necessary in two cases:
- For relocations targetting sub-word memory locations, there may be pieces
of the instruction at the target address which we should not override.
- Some relocations on some platforms allow an extra addend to be encoded in
their immediate fields.
The problem is that in the second case the information cannot be recovered
after the relocations have been applied once because they will have been
overridden. In the first case we also need to be careful to not use any bits
that aren't fixed and may have been overriden by applying a first relocation.
In the past both have been fixed by just looking at original object file. This
patch attempts to recover the information from the first by looking at the
relocated object file, while the extra addend in the second case is read
upon relocation processing and addend to the regular addend.
I have tested this on X86. Other platforms represent my best understanding
of how those relocations should work, but I may have missed something because
I do not have access to those platforms.
We will keep the ugly workarounds in place for a couple of days, so this commit
can be reverted if it breaks the bots.
Reviewers: petarj, t.p.northover, lhames
Reviewed By: lhames
Subscribers: aemerson, llvm-commits
Differential Revision: http://reviews.llvm.org/D9028
llvm-svn: 235060
Summary:
This is the first in a series of patches to eventually add support for TLS relocations to RuntimeDyld. This patch resolves an issue in the current GOT handling, where GOT entries would be reused between object files, which leads to the same situation that necessitates the GOT in the first place, i.e. that the 32-bit offset can not cover all of the address space. Thus this patch makes the GOT object-file-local.
Unfortunately, this still isn't quite enough, because the MemoryManager does not yet guarantee that sections are allocated sufficiently close to each other, even if they belong to the same object file. To address this concern, this patch also adds a small API abstraction on top of the GOT allocation mechanism that will allow (temporarily, until the MemoryManager is improved) using the stub mechanism instead of allocating a different section. The actual switch from separate section to stub mechanism will be part of a follow-on commit, so that it can be easily reverted independently at the appropriate time.
Test Plan: Includes a test case where the GOT of two object files is artificially forced to be apart by several GB.
Reviewers: lhames
Reviewed By: lhames
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D8813
llvm-svn: 234839
MCJIT.
This patch decouples the two responsibilities of the RTDyldMemoryManager class,
memory management and symbol resolution, into two new classes:
RuntimeDyld::MemoryManager and RuntimeDyld::SymbolResolver.
The symbol resolution interface is modified slightly, from:
uint64_t getSymbolAddress(const std::string &Name);
to:
RuntimeDyld::SymbolInfo findSymbol(const std::string &Name);
The latter passes symbol flags along with symbol addresses, allowing RuntimeDyld
and others to reason about non-strong/non-exported symbols.
The memory management interface removes the following method:
void notifyObjectLoaded(ExecutionEngine *EE,
const object::ObjectFile &) {}
as it is not related to memory management. (Note: Backwards compatibility *is*
maintained for this method in MCJIT and OrcMCJITReplacement, see below).
The RTDyldMemoryManager class remains in-tree for backwards compatibility.
It inherits directly from RuntimeDyld::SymbolResolver, and indirectly from
RuntimeDyld::MemoryManager via the new MCJITMemoryManager class, which
just subclasses RuntimeDyld::MemoryManager and reintroduces the
notifyObjectLoaded method for backwards compatibility).
The EngineBuilder class retains the existing method:
EngineBuilder&
setMCJITMemoryManager(std::unique_ptr<RTDyldMemoryManager> mcjmm);
and includes two new methods:
EngineBuilder&
setMemoryManager(std::unique_ptr<MCJITMemoryManager> MM);
EngineBuilder&
setSymbolResolver(std::unique_ptr<RuntimeDyld::SymbolResolver> SR);
Clients should use EITHER:
A single call to setMCJITMemoryManager with an RTDyldMemoryManager.
OR (exclusive)
One call each to each of setMemoryManager and setSymbolResolver.
This patch should be fully compatible with existing uses of RTDyldMemoryManager.
If it is not it should be considered a bug, and the patch either fixed or
reverted.
If clients find the new API to be an improvement the goal will be to deprecate
and eventually remove the RTDyldMemoryManager class in favor of the new classes.
llvm-svn: 233509
This has wider implications than I expected when I reviewed the patch: It can
cause JIT crashes where clients have used the default value for AbortOnFailure
during symbol lookup. I'm currently investigating alternative approaches and I
hope to have this back in tree soon.
llvm-svn: 227287
Support weak symbols by first looking up if there is an externally visible symbol we can find,
and only if that fails using the one in the object file we're loading.
Reviewed By: lhames
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D6950
llvm-svn: 227228
RuntimeDyld symbol info previously consisted of just a Section/Offset pair. This
patch replaces that pair type with a SymbolInfo class that also tracks symbol
visibility. A new method, RuntimeDyld::getExportedSymbolLoadAddress, is
introduced which only returns a non-zero result for exported symbols. For
non-exported or non-existant symbols this method will return zero. The
RuntimeDyld::getSymbolAddress method retains its current behavior, returning
non-zero results for all symbols regardless of visibility.
No in-tree clients of RuntimeDyld are changed. The newly introduced
functionality will be used by the Orc APIs.
No test case: Since this patch doesn't modify the behavior for any in-tree
clients we don't have a good tool to test this with yet. Once Orc is in we can
use it to write regression tests that test these changes.
llvm-svn: 226341
All symbols have to be stored in the global symbol to enable
cross-rtdyld-instance linking, so the local symbol table content is
redundant.
llvm-svn: 222867
Previously, when loading an object file, RuntimeDyld (1) took ownership of the
ObjectFile instance (and associated MemoryBuffer), (2) potentially modified the
object in-place, and (3) returned an ObjectImage that managed ownership of the
now-modified object and provided some convenience methods. This scheme accreted
over several years as features were tacked on to RuntimeDyld, and was both
unintuitive and unsafe (See e.g. http://llvm.org/PR20722).
This patch fixes the issue by removing all ownership and in-place modification
of object files from RuntimeDyld. Existing behavior, including debugger
registration, is preserved.
Noteworthy changes include:
(1) ObjectFile instances are now passed to RuntimeDyld by const-ref.
(2) The ObjectImage and ObjectBuffer classes have been removed entirely, they
existed to model ownership within RuntimeDyld, and so are no longer needed.
(3) RuntimeDyld::loadObject now returns an instance of a new class,
RuntimeDyld::LoadedObjectInfo, which can be used to construct a modified
object suitable for registration with the debugger, following the existing
debugger registration scheme.
(4) The JITRegistrar class has been removed, and the GDBRegistrar class has been
re-written as a JITEventListener.
This should fix http://llvm.org/PR20722 .
llvm-svn: 222810
There are two methods in SectionRef that can fail:
* getName: The index into the string table can be invalid.
* getContents: The section might point to invalid contents.
Every other method will always succeed and returning and std::error_code just
complicates the code. For example, a section can have an invalid alignment,
but if we are able to get to the section structure at all and create a
SectionRef, we will always be able to read that invalid alignment.
llvm-svn: 219314
field of RelocationValueRef, rather than the 'Addend' field.
This is consistent with RuntimeDyldELF's use of RelocationValueRef, and more
consistent with the semantics of the data being stored (the offset from the
start of a section or symbol).
llvm-svn: 217328
Summary:
Introduce support::ulittleX_t::ref type to Support/Endian.h and use it in x86 JIT
to enforce correct endianness and fix unaligned accesses.
Test Plan: regression test suite
Reviewers: lhames
Subscribers: ributzka, llvm-commits
Differential Revision: http://reviews.llvm.org/D5011
llvm-svn: 216631
The expressions 'Reloc.Addend - Addend' and 'Reloc.Offset' should always be
equal in this context. The latter is prefered - we want to remove the
RelocationValueRef::Addend field in the future.
llvm-svn: 216418
Owning the buffer is somewhat inflexible. Some Binaries have sub Binaries
(like Archive) and we had to create dummy buffers just to handle that. It is
also a bad fit for IRObjectFile where the Module wants to own the buffer too.
Keeping this ownership would make supporting IR inside native objects
particularly painful.
This patch focuses in lib/Object. If something elsewhere used to own an Binary,
now it also owns a MemoryBuffer.
This patch introduces a few new types.
* MemoryBufferRef. This is just a pair of StringRefs for the data and name.
This is to MemoryBuffer as StringRef is to std::string.
* OwningBinary. A combination of Binary and a MemoryBuffer. This is needed
for convenience functions that take a filename and return both the
buffer and the Binary using that buffer.
The C api now uses OwningBinary to avoid any change in semantics. I will start
a new thread to see if we want to change it and how.
llvm-svn: 216002
Having both Triple::arm64 and Triple::aarch64 is extremely confusing, and
invites bugs where only one is checked. In reality, the only legitimate
difference between the two (arm64 usually means iOS) is also present in the OS
part of the triple and that's what should be checked.
We still parse the "arm64" triple, just canonicalise it to Triple::aarch64, so
there aren't any LLVM-side test changes.
llvm-svn: 213743
This patch enables the new ELFv2 ABI in the runtime dynamic loader.
The loader has to implement the following features:
- In the ELFv2 ABI, do not look up a function descriptor in .opd, but
instead use the local entry point when resolving a direct call.
- Update the TOC restore code to use the new TOC slot linkage area
offset.
- Create PLT stubs appropriate for the ELFv2 ABI.
Note that this patch also adds common-code changes. These are necessary
because the loader must check the newly added ELF flags: the e_flags
header bits encoding the ABI version, and the st_other symbol table
entry bits encoding the local entry point offset. There is currently
no way to access these, so I've added ObjectFile::getPlatformFlags and
SymbolRef::getOther accessors.
Reviewed by Hal Finkel.
llvm-svn: 213491
Current PPC64 RuntimeDyld code to handle TOC relocations has two
problems:
- With recent linkers, in addition to the relocations that implicitly
refer to the TOC base (R_PPC64_TOC*), you can now also use the .TOC.
magic symbol with any other relocation to refer to the TOC base
explicitly. This isn't currently used much in ELFv1 code (although
it could be), but it is essential in ELFv2 code.
- In a complex JIT environment with multiple modules, each module may
have its own .toc section, and TOC relocations in one module must
refer to *its own* TOC section. The current findPPC64TOC implementation
does not correctly implement this; in fact, it will always return the
address of the first TOC section it finds anywhere. (Note that at the
time findPPC64TOC is called, we don't even *know* which module the
relocation originally resided in, so it is not even possible to fix
this routine as-is.)
This commit fixes both problems by handling TOC relocations earlier, in
processRelocationRef. To do this, I've removed the findPPC64TOC routine
and replaced it by a new routine findPPC64TOCSection, which works
analogously to findOPDEntrySection in scanning the sections of the
ObjImage provided by its caller, processRelocationRef. This solves the
issue of finding the correct TOC section associated with the current
module.
This makes it straightforward to implement both R_PPC64_TOC relocations,
and relocations explicitly refering to the .TOC. symbol, directly in
processRelocationRef. There is now a new problem in implementing the
R_PPC64_TOC16* relocations, because those can now in theory involve
*three* different sections: the relocation may be applied in section A,
refer explicitly to a symbol in section B, and refer implicitly to the
TOC section C. The final processing of the relocation thus may only
happen after all three of these sections have been assigned final
addresses. There is currently no obvious means to implement this in
its general form with the common-code RuntimeDyld infrastructure.
Fortunately, ppc64 code usually makes no use of this most general form;
in fact, TOC16 relocations are only ever generated by LLVM for symbols
residing themselves in the TOC, which means "section B" == "section C"
in the above terminology. This special case can easily be handled with
the current infrastructure, and that is what this patch does.
[ Unhandled cases result in an explicit error, unlike the current code
which silently returns the wrong TOC base address ... ]
This patch makes the JIT work on both BE and LE (ELFv2 requires
additional patches, of course), and allowed me to successfully run
complex JIT scenarios (via mesa/llvmpipe).
Reviewed by Hal Finkel.
llvm-svn: 211885
When RuntimeDyldELF creates stub functions, it needs to install
relocations that will resolve to the final address of the target
routine. Since those are 16-bit relocs, they need to be applied to the
least-significant halfword of the instruction. On big-endian ppc64,
this means that addresses have to be adjusted by 2, which is what the
code currently does.
However, on a little-endian system, the address must *not* be adjusted;
the least-significant halfword is the first one. This patch updates the
RuntimeDyldELF code to take the target byte order into account.
llvm-svn: 211384
This adds support for several missing PPC64 relocations in the
straight-forward manner to RuntimeDyldELF.cpp.
Note that this actually fixes a failure of a large-model test case on
PowerPC, allowing the XFAIL to be removed.
llvm-svn: 211382
