31 Commits

Author SHA1 Message Date
Amir Ayupov
9b02dc631d [BOLT] Check MCContext errors
Abort on emission errors to prevent a malformed binary being written.
Example:
```
<unknown>:0: error: Undefined temporary symbol .Ltmp26310
<unknown>:0: error: Undefined temporary symbol .Ltmp26311
<unknown>:0: error: Undefined temporary symbol .Ltmp26312
<unknown>:0: error: Undefined temporary symbol .Ltmp26313
<unknown>:0: error: Undefined temporary symbol .Ltmp26314
<unknown>:0: error: Undefined temporary symbol .Ltmp26315
BOLT-ERROR: Emission failed.
```

Reviewed By: yota9

Differential Revision: https://reviews.llvm.org/D123263
2022-04-08 21:08:39 -07:00
Vladislav Khmelevsky
4956e0e197 [BOLT] Fix plt relocations symbol match
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
2022-04-05 15:57:26 +03:00
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
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
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
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
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
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
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
Maksim Panchenko
df288e8487 [BOLT][NFC] Refactor if statements in RewriteInstance
(cherry picked from FBD33341796)
2021-12-28 13:46:45 -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
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
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
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
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