49 Commits

Author SHA1 Message Date
Vladislav Khmelevsky
3b1314f4de [BOLT] AArch64: Read all static relocations
Read static relocs on the same address, as dynamic in order to update
constant island data address properly.

Differential Revision: https://reviews.llvm.org/D122100
2022-04-03 19:03:35 +03:00
Vladislav Khmelevsky
62a289d85c [BOLT] LongJmp: Fix hot text section alignment
The BinaryEmitter uses opts::AlignText value to align the hot text
section. Also check that the opts::AlignText is at least
equal opts::AlignFunctions for the same reason, as described in D121392.

Vladislav Khmelevsky,
Advanced Software Technology Lab, Huawei

Differential Revision: https://reviews.llvm.org/D121728
2022-03-16 15:57:46 +03:00
Maksim Panchenko
57f03db195 [BOLT][NFC] Remove unused function
Reviewed By: yota9

Differential Revision: https://reviews.llvm.org/D121729
2022-03-15 12:39:14 -07:00
Amir Ayupov
d1638cb0b5 [BOLT][NFC] Fix print-cfg data race
Addresses ThreadSanitizer warning

Reviewed By: rafauler

Differential Revision: https://reviews.llvm.org/D121337
2022-03-09 20:28:06 -08:00
Amir Ayupov
d16bbc5340 [BOLT][NFC] Check errors from Obj.dynamicEntries
Addresses fuzzer crash

Reviewed By: rafauler

Differential Revision: https://reviews.llvm.org/D121336
2022-03-09 20:24:44 -08:00
Vladislav Khmelevsky
8bdbcfe7d8 [BOLT] Handle ifuncs trampolines for aarch64
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
2022-03-09 01:38:19 +03:00
Amir Ayupov
1e016c3bd5 [BOLT][NFC] Handle "dynamic section sizes should match"
Address fuzzer crash on malformed input

Reviewed By: rafauler

Differential Revision: https://reviews.llvm.org/D121070
2022-03-08 13:03:05 -08:00
Amir Ayupov
687e4af1c0 [BOLT] CMOVConversion pass
Convert simple hammocks into cmov based on misprediction rate.

Test Plan:
- Assembly test: `cmov-conversion.s`
- Testing on a binary:
  # Bootstrap clang with `-x86-cmov-converter-force-all` and `-Wl,--emit-relocs`
  (Release build)
  # Collect perf.data:

    - `clang++ <opts> bolt/lib/Core/BinaryFunction.cpp -E > bf.cpp`
    - `perf record -e cycles:u -j any,u -- clang-15 bf.cpp -O2 -std=c++14 -c -o bf.o`
  # Optimize clang-15 with and w/o -cmov-conversion:
    - `llvm-bolt clang-15 -p perf.data -o clang-15.bolt`
    - `llvm-bolt clang-15 -p perf.data -cmov-conversion -o clang-15.bolt.cmovconv`
  # Run perf experiment:
    - test: `clang-15.bolt.cmovconv`,
    - control: `clang-15.bolt`,
    - workload (clang options): `bf.cpp -O2 -std=c++14 -c -o bf.o`
Results:
```
  task-clock [delta: -360.21 ± 356.75, delta(%): -1.7760 ± 1.7589, p-value: 0.047951, balance: -6]
  instructions  [delta: 44061118 ± 13246382, delta(%): 0.0690 ± 0.0207, p-value: 0.000001, balance: 50]
  icache-misses [delta: -5534468 ± 2779620, delta(%): -0.4331 ± 0.2175, p-value: 0.028014, balance: -28]
  branch-misses [delta: -1624270 ± 1113244, delta(%): -0.3456 ± 0.2368, p-value: 0.030300, balance: -22]
```

Reviewed By: rafauler

Differential Revision: https://reviews.llvm.org/D120177
2022-03-08 10:44:31 -08:00
Amir Ayupov
ced5472e09 [BOLT][NFC] Check section contents before registering it
Address fuzzer crash on malformed input:
```
BOLT-ERROR: cannot get section contents for .dynsym: The end of the file was unexpectedly encountered.
```

Reviewed By: rafauler

Differential Revision: https://reviews.llvm.org/D121068
2022-03-08 09:13:01 -08:00
Vladislav Khmelevsky
00b6efc830 [BOLT] Enable PLT analysis for aarch64
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
2022-03-02 22:14:48 +03:00
Maksim Panchenko
4101aa130a [BOLT] Support PC-relative relocations with addends
PC-relative memory operand could reference a different object from
the one located at the target address, e.g. when a negative offset
is used. Check relocations for the real referenced object.

Reviewed By: rafauler

Differential Revision: https://reviews.llvm.org/D120379
2022-02-23 22:54:42 -08:00
Amir Ayupov
af6e66f44c [BOLT][NFC] Report errors from RewriteInstance discoverStorage and run
Further improve error handling in BOLT by reporting `RewriteInstance` errors in
a library and fuzzer-friendly way instead of exiting.

Follow-up to D119658

Reviewed By: rafauler

Differential Revision: https://reviews.llvm.org/D120224
2022-02-23 20:42:39 -08:00
Alexander Yermolovich
210bb04e23 [BOLT][DWARF] Remove patchLowHigh unused function.
Cleanup after removing caching mechanims for ranges/abbrevs.

Reviewed By: rafauler, yota9

Differential Revision: https://reviews.llvm.org/D120174
2022-02-22 13:28:15 -08:00
Amir Ayupov
d44f99c748 [BOLT] Added fuzzer target (llvm-bolt-fuzzer)
This adds a target that would consume random binary as an
input ELF file.
TBD: add structured input support (ELF).

Build:
```
cmake /path/to/llvm-project/llvm -GNinja \
-DLLVM_TARGETS_TO_BUILD="X86;AArch64" \
-DCMAKE_BUILD_TYPE=Release \
-DLLVM_ENABLE_ASSERTIONS=1 \
-DCMAKE_C_COMPILER=<sanitizer-capable clang> \
-DCMAKE_CXX_COMPILER=<sanitizer-capable clang++> \
-DLLVM_ENABLE_PROJECTS="bolt"  \
-DLLVM_USE_SANITIZER=Address \
-DLLVM_USE_SANITIZE_COVERAGE=On
ninja llvm-bolt-fuzzer
```

Test Plan: ninja llvm-bolt-fuzzer

Reviewed By: maksfb

Differential Revision: https://reviews.llvm.org/D120016
2022-02-20 17:24:16 -08:00
Amir Ayupov
32d2473a5d [BOLT][NFC] Report errors from createBinaryContext and RewriteInstance ctor
Refactor createBinaryContext and RewriteInstance/MachORewriteInstance
constructors to report an error in a library and fuzzer-friendly way instead of
returning a nullptr or exiting.

Reviewed By: rafauler

Differential Revision: https://reviews.llvm.org/D119658
2022-02-17 00:50:52 -08:00
Vladislav Khmelevsky
729d29e167 [BOLT] Update dynamic relocations from section relocations
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
2022-02-16 18:40:54 +03:00
Alexander Yermolovich
bd1ebe9d04 [BOLT][DWARF] Add ability to insert new entries in to DIE
Added ability to append new entries to DIE. This is useful to standadize DWARF4
Split Dwarf, and simplify implementation of DWARF5.
Multiple DIEs can share an abbrev. So currently limitation is that only unique
Attributes can be added.

Reviewed By: maksfb

Differential Revision: https://reviews.llvm.org/D119577
2022-02-15 18:07:19 -08:00
serge-sans-paille
290e482342 Cleanup LLVMDWARFDebugInfo
As usual with that header cleanup series, some implicit dependencies now need to
be explicit:

llvm/DebugInfo/DWARF/DWARFContext.h no longer includes:
- "llvm/DebugInfo/DWARF/DWARFAcceleratorTable.h"
- "llvm/DebugInfo/DWARF/DWARFCompileUnit.h"
- "llvm/DebugInfo/DWARF/DWARFDebugAbbrev.h"
- "llvm/DebugInfo/DWARF/DWARFDebugAranges.h"
- "llvm/DebugInfo/DWARF/DWARFDebugFrame.h"
- "llvm/DebugInfo/DWARF/DWARFDebugLoc.h"
- "llvm/DebugInfo/DWARF/DWARFDebugMacro.h"
- "llvm/DebugInfo/DWARF/DWARFGdbIndex.h"
- "llvm/DebugInfo/DWARF/DWARFSection.h"
- "llvm/DebugInfo/DWARF/DWARFTypeUnit.h"
- "llvm/DebugInfo/DWARF/DWARFUnitIndex.h"

Plus llvm/Support/Errc.h not included by a bunch of llvm/DebugInfo/DWARF/DWARF*.h files

Preprocessed lines to build llvm on my setup:
after: 1065629059
before: 1066621848

Which is a great diff!

Discourse thread: https://discourse.llvm.org/t/include-what-you-use-include-cleanup
Differential Revision: https://reviews.llvm.org/D119723
2022-02-15 09:16:03 +01:00
Alexander Yermolovich
0d9921daad [BOLT][DWARF] Remove caching of ranges/abbrevs
Removing caching of ranges/abbrevs to simplify the code.
Before we were doing it to get around a gdb limitation.
FBD34015613

Reviewed By: Amir, maksfb

Differential Revision: https://reviews.llvm.org/D119276
2022-02-08 16:37:40 -08:00
Amir Ayupov
194b164eb5 [BOLT][NFC] Fix compiler warnings
Summary:
- variable 'TotalSize' set but not used
- variable 'TotalCallsTopN' set but not used
- use of bitwise '|' with boolean operands

Reviewed By: maksfb

FBD33911129
2022-02-04 15:57:33 -08:00
Alexander Yermolovich
612f0f4568 [BOLT][DWARF] Fix gdb index section
Since we now re-write .debug_info the DWARF CU Offsets can change.
Just like for .debug_aranges the GDB Index will need to be updated.

Reviewed By: Amir, maksfb

Differential Revision: https://reviews.llvm.org/D118273
2022-01-27 12:07:58 -08:00
Vladislav Khmelevsky
20e9d4caf0 [BOLT] Prepare BOLT for unit-testing
This patch adds unit testing support for BOLT. In order to do this we will need at least do this changes on the code level:
* Make createMCPlusBuilder accessible externally
* Remove positional InputFilename argument to bolt utlity sources
And prepare the cmake and lit for the new tests.

Vladislav Khmelevsky,
Advanced Software Technology Lab, Huawei

Reviewed By: maksfb, Amir

Differential Revision: https://reviews.llvm.org/D118271
2022-01-27 00:22:13 +03:00
Amir Ayupov
f8c7fb499b [BOLT][NFC] Reduce includes with include-what-you-use
Summary: Removed redundant includes with IWYU

Test Plan: ninja bolt

Reviewers: maksfb

FBD32043568
2022-01-21 12:05:47 -08:00
Amir Ayupov
a9cd49d50e [BOLT][NFC] Move Offset annotation to Group 1
Summary:
Move the annotation to avoid dynamic memory allocations.
Improves the CPU time of instrumenting a large binary by 1% (+-0.8%, p-value 0.01)

Test Plan: NFC

Reviewers: maksfb

FBD30091656
2022-01-18 13:24:50 -08:00
Vladislav Khmelevsky
ad4e26833f updateDWARFObjectAddressRanges: nullify low pc
In case the case the DW_AT_ranges tag already exists for the object the
low pc values won't be updated and will be incorrect in
after-bolt binaries.

Vladislav Khmelevsky,
Advanced Software Technology Lab, Huawei

Differential Revision: https://reviews.llvm.org/D117216
2022-01-18 22:37:29 +03:00
Amir Ayupov
29fe14c78d [BOLT][NFC] Remove redundant dependent template type
Summary:
Reduce code size by removing redundant dependent template type
from RewriteInstance methods.

Code size savings (via bloaty on llvm-bolt Debug build):
```
symbol,vmsize,filesize -> vmsize,filesize (delta vmsize,filesize)
updateELFSymbolTable         57096,59600 -> 56656,59048 (440,552)
updateELFSymbolTable::lambda 35957,55277 -> 35949,54485   (8,792)
getOutputSections            20592,21440 -> 20372,21156 (220,284)
getOutputSections::lambda      1792,5300 ->   1792,5372   (0,-72)

total delta (668,1556)
```

Reviewed By: maksfb

FBD33589393
2022-01-14 15:47:15 -08:00
Amir Ayupov
c34adaa3ca [BOLT][CMAKE] Use IN_LIST check
Summary:
Address @smeenai feedback https://reviews.llvm.org/D117061#inline-1122106:
>CMake has if(IN_LIST) now, which you can use instead of the string(FIND)

IN_LIST is available since CMake 3.3 released in 2015.

Reviewed By: smeenai

FBD33590959
2022-01-14 15:47:14 -08:00
Vladislav Khmelevsky
fb3b86fedc [BOLT][DWARF] Fix high pc patching
The DW_FORM_addr form of highPC address is written in absolute addres,
the data form is written in offset-from-low pc format.

Due to the large test binary the test is prepared separately in
https://github.com/rafaelauler/bolt-tests/pull/8

Vladislav Khmelevsky,
Advanced Software Technology Lab, Huawei

Reviewed By: ayermolo

Differential Revision: https://reviews.llvm.org/D117217
2022-01-15 01:05:16 +03:00
Maksim Panchenko
330c8e42ab [BOLT][NFC] Refactor command line options in BinaryPassManager
Summary:
Reformat code and put options in lexicographical order.

Comparing to clang-format output, manual formatting looks cleaner to me.

(cherry picked from FBD33481692)
2022-01-07 11:36:22 -08:00
Alexander Yermolovich
e579f5c6e7 [BOLT][DWARF] Fix race conditions for debug fission in non-deterministic mode
Summary: Adding mutexes to avoid runtime race conditions.

(cherry picked from FBD33439854)
2022-01-05 15:27:21 -08:00
Maksim Panchenko
df288e8487 [BOLT][NFC] Refactor if statements in RewriteInstance
(cherry picked from FBD33341796)
2021-12-28 13:46:45 -08:00
Alexander Yermolovich
6b89327deb [BOLT][DWARF] Handling more data formats for DW_AT_high_pc
Summary:
Adding support for DW_FORM_data_2, DW_FORM_data_1, DW_FORM_udata.
With new .debug_info code only need to modify the check.

(cherry picked from FBD33302731)
2021-12-23 14:49:14 -08:00
Alexander Yermolovich
9bf7a73787 [BOLT][DWARF] Change convertToRanges to not use indirect
Summary:
Now that we are re-writing .debug_info we are not longer restricted to have same size patches.
Simplifying logic to use direct forms.

(cherry picked from FBD32971159)
2021-12-07 17:35:12 -08:00
Alexander Yermolovich
1c2f4bbe99 [BOLT] Rewrite of .debug_info section
Summary:
Changed the behavior of how we handle .debug_info section.
Instead of patching it will now rewrite it.
With this approach we are no longer constrained to having new values
 of the same size.
It handles re-writing by treating .debug_info as raw data.
It copies chunks of data between patches, with new data written in
 between.

(cherry picked from FBD32519952)
2021-11-15 17:19:24 -08:00
Maksim Panchenko
ee0e9ccb52 [BOLTRewrite][NFC] Fix braces usages
Summary:
Refactor bolt/*/Rewrite to follow the braces rule for if/else/loop from
LLVM Coding Standards.

(cherry picked from FBD33305364)
2021-12-23 12:38:33 -08:00
Maksim Panchenko
2f09f445b2 [BOLT][NFC] Fix file-description comments
Summary: Fix comments at the start of source files.

(cherry picked from FBD33274597)
2021-12-21 10:21:41 -08:00
Maksim Panchenko
ccb99dd126 [BOLT] Fix profile and tests for nop-removal pass
Summary:
Since nops are now removed in a separate pass, the profile is consumed
on a CFG with nops. If previously a profile was generated without nops,
the offsets in the profile could be different if branches included nops
either as a source or a destination.

This diff adjust offsets to make the profile reading backwards
compatible.

(cherry picked from FBD33231254)
2021-12-18 17:05:00 -08:00
Vladislav Khmelevsky
08f56926c2 [BOLT] Move disassemble optimizations to optimization passes
Summary:
The patch moves the shortenInstructions and nop remove to separate binary
passes. As a result when llvm-bolt optimizations stage will begin the
instructions of the binary functions will be absolutely the same as it
was in the binary. This is needed for the golang support by llvm-bolt.
Some of the tests must be changed, since bb alignment nops might create
unreachable BBs in original functions.

Vladislav Khmelevsky,
Advanced Software Technology Lab, Huawei

(cherry picked from FBD32896517)
2021-12-18 17:03:35 -08:00
Elvina Yakubova
4a4045f740 [PR] Fix update-debug-sections for AArch64
Summary:
This patch adds AArch64 relocations handling in case updating of
debug sections is enabled

Elvina Yakubova,
Advanced Software Technology Lab, Huawei

(cherry picked from FBD33077609)
2021-12-08 16:53:38 +03:00
Maksim Panchenko
40c2e0fafe [BOLT][NFC] Reformat with clang-format
Summary: Selectively apply clang-format to BOLT code base.

(cherry picked from FBD33119052)
2021-12-14 16:52:51 -08:00
Amir Ayupov
6aa735ceaf [BOLT] Split functions: support fragments with multiple parents
Summary:
Gracefully handle binaries with split functions where two fragments are folded
into one, resulting in a fragment with two parent functions.

This behavior is expected in GCC8+ with -O2 optimization level, where both
function splitting and ICF are enabled by default.

On the BOLT side, the changes are:
- BinaryFunction: allow multiple parent fragments:
  - `ParentFragment` --> `ParentFragments`,
  - `setParentFragment` --> `addParentFragment`.
- BinaryContext:
  - `populateJumpTables`: mark fragments to be skipped later,
  - `registerFragment`: add a name heuristic check, return false if it failed,
  - `processInterproceduralReferences`: check if `registerFragment`
succeeded, otherwise issue a warning,
  - `skipMarkedFragments`: move out fragment traversal and skipping from
  `populateJumpTables` into a separate function.

This change fixes an issue where unrelated functions might be registered
as fragments:

```
BOLT-WARNING: interprocedural reference between unrelated fragments:
bad_gs/1(*2) and amd_decode_mce.cold.27/1(*2)
```

(Linux kernel binary)

(cherry picked from FBD32786688)
2021-12-01 21:14:56 -08:00
Maksim Panchenko
cbf530bf41 [BOLT] Add pass to normalize CFG
Summary:
Some optimizations may remove all instructions in a basic block.

The pass will cleanup the CFG afterwards by removing empty basic
blocks and merging duplicate CFG edges.

The normalized CFG is printed under '-print-normalized' option.

(cherry picked from FBD32774360)
2021-12-01 13:57:50 -08:00
Rafael Auler
a23726bb33 [BOLT] Fix crash when trying to resolve external symbols for runtime libs
Summary:
As pointed out by Vladislav in issue 217, if our RTDyld-based
linker fails to locate a symbol, it will crash with segfault. Fix that.

(cherry picked from FBD32481543)
2021-11-16 16:47:02 -08:00
Amir Ayupov
d474dbdfcb [BOLT][NFC] Use function names passed in -funcs-no-regex as-is
Summary:
Currently there are two issues rendering the use of bughunter/BOLT on a binary
with a large number of functions (100k) impossible:
1) `selectFunctionsToProcess` has O(binary_fn * force_fn) run-time, which is up
to quadratic with the number of functions in the binary.
2) It unnecessarily treats supplied function names as regexes.

This diff proposes the following changes to address the issue:
1. Add two options that treat function names as is, not as regexes, matching
bughunter usage model: `-funcs-no-regex`/`-funcs-file-no-regex`.
These options are complementary to `-funcs`/`-funcs-file` and `-skip-funcs`/
`-skip-funcs-file`. `funcs` takes precedence over `funcs-no-regex`.
2. Use string set to speed up function eligibility checking with
`-funcs-file-no-regex` to O(binary_fn * log force_fn).

(cherry picked from FBD28917225)
2021-06-04 18:49:29 -07:00
Alexander Yermolovich
68b0003ee3 [BOLT][DWARF] Fix for Unsupported Debug section: debug_line.dwo warning
Summary: Probably copy and paste mistake or something.

(cherry picked from FBD32625751)
2021-11-23 11:52:25 -08:00
Rafael Auler
ae585be11c [BOLT] Fix Windows build
Summary:
Make BOLT build in VisualStudio compiler and run without
crashing on a simple test. Other tests are not running.

(cherry picked from FBD32378736)
2021-11-11 18:14:53 -08:00
Maksim Panchenko
45f94abcd9 [BOLT][DWARF] Fix rare problem while rewriting debug_abbrev after LTO
Summary:
With LTO, it's possible for multiple DWARF compile units to share the
same abbreviation section set, i.e. to have the same abbrev_offset.
When units sharing the same abbrev set are located next to each other
and neither of them is being processed (i.e. contain processed
functions), it can trigger a bug in BOLT. When this happened,
the abbrev set is considered empty. Additionally, different units
may patch abbrev section differently.

The fix is to not rely on the next unit offset when detecting
abbreviation set boundaries and to delay writing abbrev section
until all units are processed.

(cherry picked from FBD31985046)
2021-10-27 20:28:17 -07:00
Rafael Auler
443f1b4ff4 Rebase: [BOLT] AsmDump: dump function assembly and profile info
Summary:
Added new functionality of dumping simple functions into assembly.
This includes:
- function control flow (basic blocks, instructions),
- profile information as `FDATA` directives, to be consumed by link_fdata,
- data labels,
- CFI directives,
- symbols for callee functions,
- jump table symbols.

Envisioned usage:
1. Find a function that triggers BOLT crash (e.g. with `bughunter.sh`).
2. Generate reproducer asm source for that function (using `-funcs`).
3. Attach it to an issue.
4. Reduce and include as a test case.

Current limitations:
1. Emitted assembly won't match input file relocations.
2. No DWARF support.
3. Data is not emitted.

(cherry picked from FBD32746857)
2021-09-27 10:51:25 -07:00
Rafael Auler
a34c753fe7 Rebase: [NFC] Refactor sources to be buildable in shared mode
Summary:
Moves source files into separate components, and make explicit
component dependency on each other, so LLVM build system knows how to
build BOLT in BUILD_SHARED_LIBS=ON.

Please use the -c merge.renamelimit=230 git option when rebasing your
work on top of this change.

To achieve this, we create a new library to hold core IR files (most
classes beginning with Binary in their names), a new library to hold
Utils, some command line options shared across both RewriteInstance
and core IR files, a new library called Rewrite to hold most classes
concerned with running top-level functions coordinating the binary
rewriting process, and a new library called Profile to hold classes
dealing with profile reading and writing.

To remove the dependency from BinaryContext into X86-specific classes,
we do some refactoring on the BinaryContext constructor to receive a
reference to the specific backend directly from RewriteInstance. Then,
the dependency on X86 or AArch64-specific classes is transfered to the
Rewrite library. We can't have the Core library depend on targets
because targets depend on Core (which would create a cycle).

Files implementing the entry point of a tool are transferred to the
tools/ folder. All header files are transferred to the include/
folder. The src/ folder was renamed to lib/.

(cherry picked from FBD32746834)
2021-10-08 11:47:10 -07:00