Checking ELFType == ELF::ET_CORE first skips string comparison for the
majority of cases.
Suggested by Fangrui Song in D114635 for a similar construct.
Adds JSONScopedPrinter to llvm-readelf. It includes an empty
JSONELFDumper class which will be used to override any LLVMELFDumper
methods which utilize startLine() which JSONScopedPrinter cannot
provide.
This introduces a change where calls to llvm-readelf with non-ELF object
files that specify --elf-output-style=GNU will now print file summary
information where it previously didn't.
Fixes previous Windows test failure which occured due to JSON escaping
of '\' by not relying on LIT substitution.
Reviewed By: jhenderson
Differential Revision: https://reviews.llvm.org/D114225
Adds JSONScopedPrinter to llvm-readelf. It includes an empty
JSONELFDumper class which will be used to override any LLVMELFDumper
methods which utilize startLine() which JSONScopedPrinter cannot
provide.
Reviewed By: jhenderson
Differential Revision: https://reviews.llvm.org/D114225
This patch implements PAC return address signing for armv8-m. This patch roughly
accomplishes the following things:
- PAC and AUT instructions are generated.
- They're part of the stack frame setup, so that shrink-wrapping can move them
inwards to cover only part of a function
- The auth code generated by PAC is saved across subroutine calls so that AUT
can find it again to check
- PAC is emitted before stacking registers (so that the SP it signs is the one
on function entry).
- The new pseudo-register ra_auth_code is mentioned in the DWARF frame data
- With CMSE also in use: PAC is emitted before stacking FPCXTNS, and AUT
validates the corresponding value of SP
- Emit correct unwind information when PAC is replaced by PACBTI
- Handle tail calls correctly
Some notes:
We make the assembler accept the `.save {ra_auth_code}` directive that is
emitted by the compiler when it saves a register that contains a
return address authentication code.
For EHABI we need to have the `FrameSetup` flag on the instruction and
handle the `t2PACBTI` opcode (identically to `t2PAC`), so we can emit
`.save {ra_auth_code}`, instead of `.save {r12}`.
For PACBTI-M, the instruction which computes return address PAC should use SP
value before adjustment for the argument registers save are (used for variadic
functions and when a parameter is is split between stack and register), but at
the same it should be after the instruction that saves FPCXT when compiling a
CMSE entry function.
This patch moves the varargs SP adjustment after the FPCXT save (they are never
enabled at the same time), so in a following patch handling of the `PAC`
instruction can be placed between them.
Epilogue emission code adjusted in a similar manner.
PACBTI-M code generation should not emit any instructions for architectures
v6-m, v8-m.base, and for A- and R-class cores. Diagnostic message for such cases
is handled separately by a future ticket.
note on tail calls:
If the called function has four arguments that occupy registers `r0`-`r3`, the
only option for holding the function pointer itself is `r12`, but this register
is used to keep the PAC during function/prologue epilogue and clobbers the
function pointer.
When we do the tail call we need the five registers (`r0`-`r3` and `r12`) to
keep six values - the four function arguments, the function pointer and the PAC,
which is obviously impossible.
One option would be to authenticate the return address before all callee-saved
registers are restored, so we have a scratch register to temporarily keep the
value of `r12`. The issue with this approach is that it violates a fundamental
invariant that PAC is computed using CFA as a modifier. It would also mean using
separate instructions to pop `lr` and the rest of the callee-saved registers,
which would offset the advantages of doing a tail call.
Instead, this patch disables indirect tail calls when the called function take
four or more arguments and the return address sign and authentication is enabled
for the caller function, conservatively assuming the caller function would spill
LR.
This patch is part of a series that adds support for the PACBTI-M extension of
the Armv8.1-M architecture, as detailed here:
https://community.arm.com/arm-community-blogs/b/architectures-and-processors-blog/posts/armv8-1-m-pointer-authentication-and-branch-target-identification-extension
The PACBTI-M specification can be found in the Armv8-M Architecture Reference
Manual:
https://developer.arm.com/documentation/ddi0553/latest
The following people contributed to this patch:
- Momchil Velikov
- Ties Stuij
Reviewed By: danielkiss
Differential Revision: https://reviews.llvm.org/D112429
Summary:
This is a NFC patch moving the GNUELFDumper<ELFT>::printEnum()
function from ELFDumper into ScopedPrinter.h for reuse.
Reviewed By: jhenderson
Differential Revision: https://reviews.llvm.org/D114840
The only binary-format-related field in the BBAddrMap structure is the function address (`Addr`), which will use uint64_t in 64B format and uint32_t in 32B format. This patch changes it to use uint64_t in both formats.
This allows non-templated use of the struct, at the expense of a marginal additional size overhead for the 32-bit format. The size of the BB address map section does not change.
Differential Revision: https://reviews.llvm.org/D112679
Notes generated in OpenBSD core files provide additional information
about the kernel state and CPU registers. These notes are described
in core.5, which can be viewed here: https://man.openbsd.org/core.5
Differential Revision: https://reviews.llvm.org/D111966
By default, such a non-template variable of non-volatile const-qualified type
having namespace-scope has internal linkage ([basic.link]), so no need for `static`.
Currently -W and --wide are treated as two options as they are only
included for gnu readelf compatibility and ignored. This change makes -W
an alias of --wide to be consistent with other option aliases.
Differential Revision: https://reviews.llvm.org/D111731
This moves the registry higher in the LLVM library dependency stack.
Every client of the target registry needs to link against MC anyway to
actually use the target, so we might as well move this out of Support.
This allows us to ensure that Support doesn't have includes from MC/*.
Differential Revision: https://reviews.llvm.org/D111454
This change is to keep the help text and command guide of llvm-readelf
in tandem.
- In the help text mention that --section-data, --section-relocations,
--section-symbols and --stack-sizes have no effect on GNU style
output; give the accepted values for --elf-output-style and update
the description of --gnu-hash-table to use the command guide
description.
- In the command guide add the missing options -a,
--dependant-libraries,--no-demangle, --wide and -W. Also update the
description of --symbols so it matches the help text.
Differential Revision: https://reviews.llvm.org/D111240
As described on D111049, we're trying to remove the <string> dependency from error handling and replace uses of report_fatal_error(const std::string&) with the Twine() variant which can be forward declared.
As described on D111049, we're trying to remove the <string> dependency from error handling and replace uses of report_fatal_error(const std::string&) with the Twine() variant which can be forward declared.
We can use the raw_string_ostream::str() method to perform the implicit flush() and return a reference to the std::string container that we can then wrap inside Twine().
The MSP430 ABI supports build attributes for specifying
the ISA, code model, data model and enum size in ELF object files.
Differential Revision: https://reviews.llvm.org/D107969
This syncs parts from the x86 implementation to the ARMWinEH
implementation.
Currently, neither of the compilers targeting COFF/arm64 (MSVC, LLVM)
produce such relocations, but LLVM might after a later patch.
Differential Revision: https://reviews.llvm.org/D109650
This is the same as we do on arm64 already for the MSVC style label
symbols, but also handle the way GCC produces it - with all relocations
pointing at the .text section symbol, with various offsets.
Differential Revision: https://reviews.llvm.org/D109649
Allow variable number of directories, as allowed by the
specification. NumberOfRvaAndSize will default to 16 if not specified,
as in the past.
Reviewed by: jhenderson
Differential Revision: https://reviews.llvm.org/D108825
Summary: This patch is trying to add support for llvm-readobj
--needed-libs option under XCOFF.
For XCOFF, the needed libraries can be found from the Import
File ID Name Table of the Loader Section.
Currently, I am using binary inputs in the test since yaml2obj
does not yet support for writing the Loader Section and the
import file table.
Reviewed By: jhenderson
Differential Revision: https://reviews.llvm.org/D106643
Support XCOFFDumper relocation reading support
This patch is part of D103696 partition
Reviewed By: daltenty, Helflym
Differential Revision: https://reviews.llvm.org/D104646
The current implementation of printAttributes makes it fiddly to extend
attribute support for new targets.
By refactoring the code so all target specific variables are
initialized in a switch/case statement, it becomes simpler to extend
attribute support for new targets.
Reviewed By: jhenderson, MaskRay
Differential Revision: https://reviews.llvm.org/D107968
The new ELF notes are added in clang-offload-wrapper, and llvm-readobj has to visualize them properly.
Differential Revision: https://reviews.llvm.org/D99552
item of StringTable.
Summary: For the string table in XCOFF, the first 4 bytes
contains the length of the string table, so we should
print the string entries from fifth bytes. This patch
also adds tests for llvm-readobj dumping the string
table.
Reviewed By: jhenderson
Differential Revision: https://reviews.llvm.org/D105522
When we build with split dwarf in single mode the .o files that contain both "normal" debug sections and dwo sections, along with relocaiton sections for "normal" debug sections.
When we create DWARF context in DWARFObjInMemory we process relocations and store them in the map for .debug_info, etc section.
For DWO Context we also do it for non dwo dwarf sections. Which I believe is not necessary. This leads to a lot of memory being wasted. We observed 70GB extra memory being used.
I went with context sensitive approach, flag is passed in. I am not sure if it's always safe not to process relocations for regular debug sections if Obj contains .dwo sections.
If it is alternatvie might be just to scan, in constructor, sections and if there are .dwo sections not to process regular debug ones.
Reviewed By: dblaikie
Differential Revision: https://reviews.llvm.org/D106624
[[noreturn]] can be used since Oct 2016 when the minimum compiler requirement was bumped to GCC 4.8/MSVC 2015.
Note: the definition of LLVM_ATTRIBUTE_NORETURN is kept for now.
The current implementation of displaying .stack_size information
presumes that each entry represents a single function but this is not
always the case. For example with the use of ICF multiple functions can
be represented with the same code, meaning that the address found in a
.stack_size entry corresponds to multiple function symbols.
This change allows multiple function names to be displayed when
appropriate.
Differential Revision: https://reviews.llvm.org/D105884
llvm-readelf is a user-facing tool which emulates GNU readelf. Remove one-dash
long options which are not recognized by GNU style `getopt_long`. This ensures
long options cannot collide with grouped short options.
Note: the documentation (D63719)/help messages have recommended the double-dash
forms since LLVM 9.0.0.
llvm-readobj is intended as an internal tool which has some flexibility.
llvm-readelf/llvm-readobj use the same option parsing code and llvm-readobj's
one-dash long options aren't used after test migration.
Differential Revision: https://reviews.llvm.org/D106037
This is a follow up to https://reviews.llvm.org/D104080, and ca3bdb57fa (diff-e64a48fabe31db213a631fdc5f2acb51bdddf3f16a8fb2928784f4c579229585). The implementation of call graph profile was changed from a black box section to relocation approach. This was done to be compatible with post processing tools like strip/objcopy, and llvm equivalent. When they are invoked on object file before the final linking step with this new approach the symbol indices correctness is preserved.
The GNU binutils tools change the REL section to RELA section, unlike llvm tools. For example when strip -S is run on the ELF object files, as an intermediate step before linking. To preserve compatibility this patch extends implementation in LLD and ELFDumper to support both REL and RELA sections for call graph profile.
Reviewed By: MaskRay, jhenderson
Differential Revision: https://reviews.llvm.org/D105217
Users should generally observe no difference as long as they don't use
unintended option forms. Behavior changes:
* `-t=d` is removed. Use `-t d` instead.
* `--demangle=false` and `--demangle=0` cannot be used. Omit the option or use `--no-demangle`. Other flag-style options don't have `--no-` forms.
* `--help-list` is removed. This is a `cl::` specific option.
* llvm-readobj now supports grouped short options as well.
* `--color` is removed. This is generally not useful (only apply to errors/warnings) but was inherited from Support.
Some adjustment to the canonical forms
(usually from GNU readelf; currently llvm-readobj has too many redundant aliases):
* --dyn-syms is canonical. --dyn-symbols is a hidden alias
* --file-header is canonical. --file-headers is a hidden alias
* --histogram is canonical. --elf-hash-histogram is a hidden alias
* --relocs is canonical. --relocations is a hidden alias
* --section-groups is canonical. --elf-section-groups is a hidden alias
OptTable avoids global option collision if we decide to support multiplexing for binary utilities.
* Most one-dash long options are still supported. `-dt, -sd, -st, -sr` are dropped due to their conflict with grouped short options.
* `--section-mapping=false` (D57365) is strange but is kept for now.
* Many `cl::opt` variables were unnecessarily external. I added `static` whenever appropriate.
Reviewed By: jhenderson
Differential Revision: https://reviews.llvm.org/D105532
C++23 will make these conversions ambiguous - so fix them to make the
codebase forward-compatible with C++23 (& a follow-up change I've made
will make this ambiguous/invalid even in <C++23 so we don't regress
this & it generally improves the code anyway)
Summary: The patch adds the StringTable dumping to
llvm-readobj. Currently only XCOFF is supported.
Reviewed By: jhenderson
Differential Revision: https://reviews.llvm.org/D104613
llvm-readobj is an internal testing tool for binary formats. Its output and
command line options do not need to be stable. It isn't supposed to be part of a
build process.
llvm-readelf was created as a user-facing utility and its interface intends to
be compatible with GNU readelf (unless there are good reasons not to).
The two tools have mostly compatible options. -s and -t are noticeable
exceptions due to history. I think the cost of keeping the inconsistency
overweighs the little history-compatible benefit and hinders transition from
cl::opt to OptTable, so let's change it.
Reviewed By: jhenderson
Differential Revision: https://reviews.llvm.org/D105055
... even on targets preferring RELA. The section is only consumed by ld.lld
which can handle REL.
Follow-up to D104080 as I explained in the review. There are two advantages:
* The D104080 code only handles RELA, so arm/i386/mips32 etc may warn for -fprofile-use=/-fprofile-sample-use= usage.
* Decrease object file size for RELA targets
While here, change the relocation to relocate weights, instead of 0,1,2,3,..
I failed to catch the issue during review.
Currently when .llvm.call-graph-profile is created by llvm it explicitly encodes the symbol indices. This section is basically a black box for post processing tools. For example, if we run strip -s on the object files the symbol table changes, but indices in that section do not. In non-visible behavior indices point to wrong symbols. The visible behavior indices point outside of Symbol table: "invalid symbol index".
This patch changes the format by using R_*_NONE relocations to indicate the from/to symbols. The Frequency (Weight) will still be in the .llvm.call-graph-profile, but symbol information will be in relocation section. In LLD information from both sections is used to reconstruct call graph profile. Relocations themselves will never be applied.
With this approach post processing tools that handle relocations correctly work for this section also. Tools can add/remove symbols and as long as they handle relocation sections with this approach information stays correct.
Doing a quick experiment with clang-13.
The size went up from 107KB to 322KB, aggregate of all the input sections. Size of clang-13 binary is ~118MB. For users of -fprofile-use/-fprofile-sample-use the size of object files will go up slightly, it will not impact final binary size.
Reviewed By: jhenderson, MaskRay
Differential Revision: https://reviews.llvm.org/D104080
Frederic Cambus