Currently strict mode is used to expand number of optimized functions,
not to shrink it. Revert the option usage in the pass, so passing strict
option would relax adr instruction even if there are no nops around it.
Also add check for nop after adr instruction.
BOLT currently hooks its its instrumentation finalization function via
`DT_FINI`. However, this method of calling finalization routines is not
supported anymore on newer ABIs like RISC-V. `DT_FINI_ARRAY` is
preferred there.
This patch adds support for hooking into `DT_FINI_ARRAY` instead if the
binary does not have a `DT_FINI` entry. If it does, `DT_FINI` takes
precedence so this patch should not change how the currently supported
instrumentation targets behave.
`DT_FINI_ARRAY` points to an array in memory of `DT_FINI_ARRAYSZ` bytes.
It consists of pointer-length entries that contain the addresses of
finalization functions. However, the addresses are only filled-in by the
dynamic linker at load time using relative relocations. This makes
hooking via `DT_FINI_ARRAY` a bit more complicated than via `DT_FINI`.
The implementation works as follows:
- While scanning the binary: find the section where `DT_FINI_ARRAY`
points to, read its first dynamic relocation and use its addend to find
the address of the fini function we will use to hook;
- While writing the output file: overwrite the addend of the dynamic
relocation with the address of the runtime library's fini function.
Updating the dynamic relocation required a bit of boiler plate: since
dynamic relocations are stored in a `std::multiset` which doesn't
support getting mutable references to its items, functions were added to
`BinarySection` to take an existing relocation and insert a new one.
This is an ongoing series of commits that are reformatting our
Python code. This catches the last of the python files to
reformat. Since they where so few I bunched them together.
Reformatting is done with `black`.
If you end up having problems merging this commit because you
have made changes to a python file, the best way to handle that
is to run git checkout --ours <yourfile> and then reformat it
with black.
If you run into any problems, post to discourse about it and
we will try to help.
RFC Thread below:
https://discourse.llvm.org/t/rfc-document-and-standardize-python-code-style
Reviewed By: jhenderson, #libc, Mordante, sivachandra
Differential Revision: https://reviews.llvm.org/D150784
Avoid replacing one adr instruction with two adrp+add by utilizing linker-provided nops
when they are present. By doing so we preserve relative offsets of next instructions
in a function which reduces chances to break undetected jump tables. This commit makes
release-mode lld-linked clang, lld and etc work after BOLT.
Reviewed By: rafauler, yota9
Differential Revision: https://reviews.llvm.org/D143887
This prepares for an upcoming change to make --print-imm-hex the default
behavior of llvm-objdump. These tests were updated in a semi-automatic
fashion.
See D136972 for details.
Replace a single dash with a double dash for options that have more
than a single letter.
llvm-bolt-wrapper.py has special treatment for output options such as
"-o" and "-w" causing issues when a single dash is used, e.g. for
"-write-dwp". The wrapper can be fixed as well, but using a double dash
has other advantages as well.
Reviewed By: rafauler
Differential Revision: https://reviews.llvm.org/D127538
The relocation value is calculated using the formula S + A - P,
the verification of the value is performed by inversely calculating the location address
Reviewed By: Amir
Differential Revision: https://reviews.llvm.org/D124270
tls-lld test might be broken since compiler might optimize plt function
call and use address directly from got table. The test is removed since
plt-gnu-ld checks the same functionality + versioning symbol matching,
no need to keep both of the tests.
The toolchain might optimize relocations in runtime-relocs test, replace
the test compilation with yaml files.
Differential Revision: https://reviews.llvm.org/D123332
The bfd linker adds the symbol versioning string to the symbol name in symtab.
Skip the versioning part in order to find the registered PLT function.
Vladislav Khmelevsky,
Advanced Software Technology Lab, Huawei
Differential Revision: https://reviews.llvm.org/D122039
AArch64 requires CI to be aligned to 8 bytes due to access instructions
restrictions. E.g. the ldr with imm, where imm must be aligned to 8 bytes.
Differential Revision: https://reviews.llvm.org/D122065
The aarch64 uses the trampolines located in .iplt section, which
contains plt-like trampolines on the value stored in .got. In this case
we don't have JUMP_SLOT relocation, but we have a symbol that belongs to
ifunc trampoline, so use it and set set plt symbol for such functions.
Vladislav Khmelevsky,
Advanced Software Technology Lab, Huawei
Differential Revision: https://reviews.llvm.org/D120850
This patch enables PLT analysis for aarch64. It is used by the static
relocations in order to provide final symbol address of PLT entry for some
instructions like ADRP.
Vladislav Khmelevsky,
Advanced Software Technology Lab, Huawei
Differential Revision: https://reviews.llvm.org/D118088
This patch changes patchELFAllocatableRelaSections from going through
old relocations sections and update the relocation offsets to emitting
the relocations stored in binary sections. This is needed in case we
would like to remove and add dynamic relocations during BOLT work and it
is used by golang support pass. Note: Currently we emit relocations in
the old sections, so the total number of them should be equal or less
of old number.
Testing: No special tests are neeeded, since this patch does not fix
anything or add new functionality (it only prepares to add). Every
PIC-compiled test binary will use this code and thus become a test.
But just in case the aarch64 dynamic relocations tests were added.
Vladislav Khmelevsky,
Advanced Software Technology Lab, Huawei
Reviewed By: maksfb
Differential Revision: https://reviews.llvm.org/D117612
Summary:
Add lit.local.cfg to X86 and AArch64 folders.
Fix host_arch in lit config for AArch64.
Fix AArch64 and X86 tests.
Elvina Yakubova,
Advanced Software Technology Lab, Huawei
(cherry picked from FBD31702068)
Summary:
In non-PIC binaries compiler could save absolute addresses in constant
isalnd which we should handle properly. This patch adds relocations
handling in constant islands.
Vladislav Khmelevsky,
Advanced Software Technology Lab, Huawei
(cherry picked from FBD31416848)
Summary:
This patch adds R_AARCH64_TSTBR14 and R_AARCH64_CONDBR19 relocations
support in order to handle condition branches, cbz/cnbz and tbz/tbnz
instructions correctly
Vladislav Khmelevsky,
Advanced Software Technology Lab, Huawei
(cherry picked from FBD31416734)
Summary:
Create bolt/test/runtime folder and move tests that execute the binary.
Move lit.local.cfg with host_arch check to the corresponding folder.
Addresses issue facebookincubator/BOLT#132.
AArch64/tls.c shows a different behavior with clang hence marked as XFAIL
TODO: add a check for non-exec tests for a corresponding LLVM_TARGETS_TO_BUILD.
(cherry picked from FBD31132234)
