Summary:
This commit implements new method for _start & _fini functions hooking
which allows to use relative jumps for future PIE & .so library support.
Instead of using absolute address of _start & _fini functions known on
linking stage - we'll use dynamically created trampoline functions and
use corresponding symbols in instrumentation runtime library.
As we would like to use instrumentation for dynamically loaded binaries
(with PIE & .so), thus we need to compile instrumentation library with
"-fPIC" flag to support relative address resolution for functions and
data.
For shared libraries we need to handle initialization of instrumentation
library case by using DT_INIT section entry point.
Also this commit adds detection if the binary is executable or shared
library based on existence of PT_INTERP header. In case of shared
library we save information about real library init function address
for further usage for instrumentation library init trampoline function
creation and also update DT_INIT to point instrumentation library init
function.
Functions called from init/fini functions should be called with forced
stack alignment to avoid issues with instructions which relies on it.
E.g. optimized string operations.
Vasily Leonenko,
Advanced Software Technology Lab, Huawei
(cherry picked from FBD30092316)
Summary:
Move the common code into MCPlusBuilder.h.
Use group 1 `kTailCall` MCAnnotation instead of dynamically allocated
annotation.
This diff reduces the processing time overhead to 1.5% vs using
TAILJMP opcode.
(cherry picked from FBD30055585)
Summary:
The linker can generate 8- or 16-byte entries in .plt.got and .plt.sec
sections. On X86, the main differentiator is the presence of endbr64
instruction at the beginning of the entry. Detect the instruction and
adjust the size accordingly.
(cherry picked from FBD29847639)
Summary:
.stab and .stabstr are special sections containing debugging
information and strings associated with the debugging information.
This commit adds them to the list of debugging sections, so
these sections can be removed for output binary.
Vasily Leonenko,
Advanced Software Technology Lab, Huawei
(cherry picked from FBD29746153)
Summary:
Match new direct call generated during ICP to correct pseudo probe
New call is matched to the probes of original call instruction.
(cherry picked from FBD29591662)
Summary:
Created a binary pass that records how many
times tail duplication would be used and how many cache
misses it would theoretically stop
(cherry picked from FBD29619858)
Summary:
We extended DynoStats to dump the histogram per instruction opcode. By
default the dump is turned off. Use '-print-dyno-opcode-stats' to enable
the dump.
BOLT also dumps for each instruction opcode the maximum execution count and
corresponding function name and basic block offsets where the instruction
occurs. Below is a sample of the dump:
Opcode, Execution Count, Max Exec Count, Function Name:Offset
SHR8rCL, 232, 232, _ZNK5folly14AsyncSSLSocket4goodEv:53
VPADDDYrr, 13956, 388, chacha20_encrypt_bytes.part.0/3:736
PMOVSXBWrr, 4, 2, ares_expand_name/1:264
VMOVAPSmr, 1082, 43, chacha20_encrypt_bytes.part.0/3:2864
VPSHUFBrr, 9540, 1667, chacha20_encrypt_bytes.part.0/3:4416
VPUNPCKLDQYrr, 1102, 188, jsimd_ycc_rgb_convert_avx2/1:125
VPBROADCASTQYrm, 39, 39, chacha20_encrypt_bytes.part.0/3:400
PMOVSXWDrr, 8, 2, ares_expand_name/1:264
VPORrr, 817, 129, jsimd_idct_islow_avx2/1:41
PSLLDri, 8690752, 65644, blockmix_salsa8_xor/1:1424
(cherry picked from FBD28859624)
Summary:
A binary can contain multiple PLT sections with different name and
attributes (such as an entry size). Extend the support to .plt.sec and
refactor the code to make future extensions simpler.
(cherry picked from FBD29502107)
Summary:
clang-12 now compiles bolt without warnings.
Some warnings were fixed if possible while others were suppressed by
doing (void)variable for unused variable warnings or moving code inside
assert statements of LLVM_DEBUG blocks.
(cherry picked from FBD29469054)
Summary:
Add code to read more dynamic relocations (DT_JMPREL) and enforce strict
checks that corresponding sections sizes match .dynamic entry
description.
(cherry picked from FBD29502109)
Summary:
The code for writing out dwo files wasn't handling case where DWP is an input.
Because all the sections are part of the same binary.
One note with current implementation. .debug-str.dwo will have strings for all the dwo objects.
This is because llvm-dwp de-duplicates strings and combines them in to one section. It then re-writes .debug-str-offsets.dwo to point to new .debug-str.dwo section.
(cherry picked from FBD29244835)
Summary:
Our YAML objects contain references to dynamic relocations via .dynamic,
but there are no corresponding relocation sections. Change .dynamic
contents to specify no dynamic relocations.
(cherry picked from FBD29502108)
Summary:
Move the code that handles true external references (non-unreachable)
out of a for-loop in `BinaryFunction::disassemble`.
(cherry picked from FBD29411345)
Summary:
Handle R_X86_64_64 the same way as R_X86_64_32;
`getSizeForType` takes care of the size:
```x86_64 ABI relocation types
Name Value Field Calculation
R_X86_64_64 1 word64 S + A
R_X86_64_32 10 word32 S + A
```
(cherry picked from FBD29370417)
Summary:
When we fold a function in relocation mode, make sure to clear its state
to avoid emitting relocations against undefined symbols.
(cherry picked from FBD29245320)
Summary:
Dived more in to DWARF APIs and llvm-symbolizer this is a more streamline way of doing it, and address base gets set properly.
Writing out dwo files with dwp input will be separate patch.
(cherry picked from FBD31361529)
Summary:
When indirect call is instrmented it locks SimpleHashTable's mutex on get() call.
If while locked we we receive a signal and signal handler also will call
indirect function we will end up with deadlock.
PR facebookincubator/BOLT#167
Vladislav Khmelevsky,
Advanced Software Technology Lab, Huawei
(cherry picked from FBD28909921)
Summary:
Suppresses the warning
```
src/DebugData.h:338:20: warning: 'addList' overrides a member function but is not marked 'override' [-Wsuggest-override]
```
(cherry picked from FBD28858201)
Summary:
Make bolt decode pseudo probe section in binary
For more detail of pseudo probe, check https://reviews.llvm.org/D86490.
(cherry picked from FBD28856316)
Summary:
While printing debug info for instructions, we should use line tables
from the corresponding DWARF CU which could be different from the
containing function CU in case of inlined instructions.
(cherry picked from FBD28908324)
Summary:
FBD55943 changed the way ProcessAllSections works in RuntimeDyld. After
the change, all sections, including symbol table, section table, etc.
are loaded into memory whenever ProcessAllSections is enabled.
In BOLT we rely on RuntimeDyld for processing sections with relocations.
These include most allocatable sections and additionally .debug_line.
The latter is skipped by RuntimeDyld without ProcessAllSections flag.
If we enable ProcessAllSections, we will have to deal with allocating
memory for more sections than we need (see above) and later to filter
them out.
The alternative is to mark all sections that we actually plan to use as
"required for execution" (using RuntimeDyld terminology). For
.debug_line section on ELF it means adding SHF_ALLOC flag. On MachO,
RuntimeDyld currently treats all sections as required.
(cherry picked from FBD28729398)
Summary:
This patch introduces LoopInversionPass. Its main purpose is to ensure
that the loop layout is optimal depending on the profile information. So
if profile information shows that the loop is used, the unconditional
jump instruction must be executed only once and vice-versa. Please take
a look to the pass header file and test for more details.
Also change link_fdata script a bit, to be able to change FDATA prefix,
like FileCheck does.
Vladislav Khmelevsky,
Advanced Software Technology Lab, Huawei
PR facebookincubator/BOLT#153
(cherry picked from FBD28391811)
Summary:
Implemented support for Debug Fission.
For the most part it doesn't impact Monolithic execution path.
One area that was changed is the DW_AT_low_pc/DW_AT_high_pc conversion. Before it was to DW_AT_ranges/DW_AT_low_pc, now DW_AT_low_pc is kept in same place.
Another more visible impact is in Skeleton CU the DW_AT_low_pc is replaced with DW_AT_ranges_base if it's not originally present and bolt converted ranges conversion inside the dwo units.
Output of this are multiple .dwo files with updated debug information.
(cherry picked from FBD29569788)
Summary:
Remove relocations against internal function labels, e.g. jump table
relocations, only when overwriting them.
While reading an input file with relocations, we create internal
relocations against code references (we skip PIC relocations).
Later, when we discover jump tables, we remove corresponding relocations
with the assumption that original relocations will either be ignored or
replaced by new relocations. However, it is possible to miss some
references to the jump table, in which case the original entries will
not be ignored. While such situation is abnormal, it is still a
better/safer approach to preserve relocations if we are not replacing
them with new ones.
(cherry picked from FBD28406628)
Summary:
Explicit assignment operator can be replaced with an implicit one.
Remove it to allow an implicit copy constructor:
```
bolt/src/Passes/DataflowAnalysis.h:74:8: warning: definition of
implicit copy constructor for 'ProgramPoint' is deprecated because it
has a user-declared copy assignment operator [-Wdeprecated-copy]
void operator=(const ProgramPoint &PP) {
^
bolt/src/Passes/DataflowAnalysis.h:62:14: note: in implicit copy
constructor for 'llvm::bolt::ProgramPoint' first required here
return ProgramPoint(&*Last);
```
(cherry picked from FBD28335138)
