`__bolt_instr_data_dump()` will find instrumented binary name by
iterating through entries under directory `/proc/self/map_files`,
and then open the binary and memory map it onto heap in order
to locate `.bolt.instr.tables` section to read the descriptions.
If binary name is already known and/or binary is already opened
as memory mapped, we can pass binary name and/or memory
buffer directly to `__bolt_instr_data_dump()` to save some work.
This patch adds code generation for RISCV64 instrumentation.The work
involved includes the following three points:
a) Implements support for instrumenting direct function call and jump
on RISC-V which relies on , Atomic instructions
(used to increment counters) are only available on RISC-V when the A
extension is used.
b) Implements support for instrumenting direct function inderect call
by implementing the createInstrumentedIndCallHandlerEntryBB and
createInstrumentedIndCallHandlerExitBB interfaces. In this process, we
need to accurately record the target address and IndCallID to ensure
the correct recording of the indirect call counters.
c)Implemented the RISCV64 Bolt runtime library, implemented some system
call interfaces through embedded assembly. Get the difference between
runtime addrress of .text section andstatic address in section header
table, which in turn can be used to search for indirect call
description.
However, the community code currently has problems with relocation in
some scenarios, but this has nothing to do with instrumentation. We
may continue to submit patches to fix the related bugs.
Closes https://github.com/llvm/llvm-project/issues/63097
Before merging please make sure the change to
bolt/include/bolt/Passes/StokeInfo.h is correct.
bolt/include/bolt/Passes/StokeInfo.h
```diff
// This Pass solves the two major problems to use the Stoke program without
- // proting its code:
+ // probing its code:
```
I'm still not happy about the awkward wording in this comment.
bolt/include/bolt/Passes/FixRelaxationPass.h
```
$ ed -s bolt/include/bolt/Passes/FixRelaxationPass.h <<<'9,12p'
// This file declares the FixRelaxations class, which locates instructions with
// wrong targets and fixes them. Such problems usually occures when linker
// relaxes (changes) instructions, but doesn't fix relocations types properly
// for them.
$
```
bolt/docs/doxygen.cfg.in
bolt/include/bolt/Core/BinaryContext.h
bolt/include/bolt/Core/BinaryFunction.h
bolt/include/bolt/Core/BinarySection.h
bolt/include/bolt/Core/DebugData.h
bolt/include/bolt/Core/DynoStats.h
bolt/include/bolt/Core/Exceptions.h
bolt/include/bolt/Core/MCPlusBuilder.h
bolt/include/bolt/Core/Relocation.h
bolt/include/bolt/Passes/FixRelaxationPass.h
bolt/include/bolt/Passes/InstrumentationSummary.h
bolt/include/bolt/Passes/ReorderAlgorithm.h
bolt/include/bolt/Passes/StackReachingUses.h
bolt/include/bolt/Passes/StokeInfo.h
bolt/include/bolt/Passes/TailDuplication.h
bolt/include/bolt/Profile/DataAggregator.h
bolt/include/bolt/Profile/DataReader.h
bolt/lib/Core/BinaryContext.cpp
bolt/lib/Core/BinarySection.cpp
bolt/lib/Core/DebugData.cpp
bolt/lib/Core/DynoStats.cpp
bolt/lib/Core/Relocation.cpp
bolt/lib/Passes/Instrumentation.cpp
bolt/lib/Passes/JTFootprintReduction.cpp
bolt/lib/Passes/ReorderData.cpp
bolt/lib/Passes/RetpolineInsertion.cpp
bolt/lib/Passes/ShrinkWrapping.cpp
bolt/lib/Passes/TailDuplication.cpp
bolt/lib/Rewrite/BoltDiff.cpp
bolt/lib/Rewrite/DWARFRewriter.cpp
bolt/lib/Rewrite/RewriteInstance.cpp
bolt/lib/Utils/CommandLineOpts.cpp
bolt/runtime/instr.cpp
bolt/test/AArch64/got-ld64-relaxation.test
bolt/test/AArch64/unmarked-data.test
bolt/test/X86/Inputs/dwarf5-cu-no-debug-addr-helper.s
bolt/test/X86/Inputs/linenumber.cpp
bolt/test/X86/double-jump.test
bolt/test/X86/dwarf5-call-pc-function-null-check.test
bolt/test/X86/dwarf5-split-dwarf4-monolithic.test
bolt/test/X86/dynrelocs.s
bolt/test/X86/fallthrough-to-noop.test
bolt/test/X86/tail-duplication-cache.s
bolt/test/runtime/X86/instrumentation-ind-calls.s
This commit adds support for AArch64 in instrumentation runtime library,
including AArch64 system calls.
Also this commit divides syscalls into target-specific files.
Reviewed By: rafauler, yota9
Differential Revision: https://reviews.llvm.org/D151942
Because indirect call tables use static addresses for call sites, but pc
values recorded by runtime may be subject to ASLR in PIE, we couldn't
find indirect call descriptions by their runtime address in PIE. It
resulted in [unknown] entries in profile for all indirect calls. We need
to substract base address of .text from runtime addresses to get the
corresponding static addresses. Here we create a getter for base address
of .text and substract it's return value from recorded PC values. It
converts them to static addresses, which then may be used to find the
corresponding indirect call descriptions.
Reviewed By: rafauler
Differential Revision: https://reviews.llvm.org/D154121
When a binary is instrumented with --instrumentation-sleep-time and
instrumentation-wait-forks options and lauched, the profile is
periodically written until all the forks die. The problem is that we
cannot wait for the whole process tree, and we have no way to tell when
it's safe to read the profile. Hovewer, if we keep profile open
throughout the life of the process tree, we can use fuser to determine
when writing is finished.
Reviewed By: rafauler
Differential Revision: https://reviews.llvm.org/D154436
The issue was caused by the absence of placement new definition. It
worked for clang and thus passed Phabricator checks, but broke when
compiled with GCC on buildbot.
Full problem description: https://reviews.llvm.org/D153771#4468239
Original patch description:
In absence of instrumentation-file-append-pid option,
global allocator uses shared pages for allocation. However, since it is a
global variable, it gets COW'd after fork if instrumentation-sleep-time
is used, or if a process forks by itself. This means it handles the same
pages to every process which causes hash table corruption. Thus, if we
want shared pages, we need to put the allocator itself in a shared page,
which we do in this commit in __bolt_instr_setup.
I also added a couple of assertions to sanity-check the hash table.
Reviewed By: rafauler, Amir
Differential Revision: https://reviews.llvm.org/D153771
In a very rare case that mmap call fails, we'll at least get a message
instead of segfault.
Reviewed By: rafauler, Amir
Differential Revision: https://reviews.llvm.org/D154056
Since there are no other means to debug the instrumentation library
other than using stdout, having a function to print hash table entries
is very useful.
Reviewed By: rafauler, Amir
Differential Revision: https://reviews.llvm.org/D153771
In absence of instrumentation-file-append-pid option,
global allocator uses shared pages for allocation. However, since it is a
global variable, it gets COW'd after fork if instrumentation-sleep-time
is used, or if a process forks by itself. This means it handles the same
pages to every process which causes hash table corruption. Thus, if we
want shared pages, we need to put the allocator itself in a shared page,
which we do in this commit in __bolt_instr_setup.
I also added a couple of assertions to sanity-check the hash table.
Reviewed By: rafauler, Amir
Differential Revision: https://reviews.llvm.org/D153771
The point of append-pid option is to record separate profiles for
separate forks, which is impossible when counters are the same for
every process. It leads to a sum of all profiles in every file, plus
GlobalWriteProfileMutex located in a shared memory prevents some
processes from dumping their data at all.
Reviewed By: rafauler, Amir
Differential Revision: https://reviews.llvm.org/D153771
In a very rare case that mmap call fails, we'll at least get a message
instead of segfault.
Reviewed By: rafauler, Amir
Differential Revision: https://reviews.llvm.org/D154056
The BOLT instrumentation runtime uses a bump allocator that has a fixed amount of maximum memory. In some cases, this memory limit is not large enough (https://github.com/llvm/llvm-project/issues/59174). We are hitting this limit when instrumenting the Rust compiler with BOLT.
This change increases the memory of the bump allocator used for writing the resulting BOLT profile.
Reviewed By: rafauler
Differential Revision: https://reviews.llvm.org/D151891
`__bolt_instr_data_dump()` does not lock the hash tables when iterating
over them, so the iteration can happen concurrently with a modification
done in another thread, when the table is in an inconsistent state. This
also has been observed in practice, when it caused a segmentation fault.
We fix this by locking hash tables during iteration. This is done by taking
the lock in `forEachElement()`.
The only other site of iteration, `resetCounters()`, has been correctly
locking the table even before this patch. This patch removes its `Lock`
because the lock is now taken in the inner `forEachElement()`.
Reviewed By: maksfb, yota9
Differential Revision: https://reviews.llvm.org/D129089
Compiler can generate calls to some functions implicitly, even under
constraints of freestanding environment. Make sure these functions are
available in our runtime objects.
Fixes test failures on some systems after https://reviews.llvm.org/D128960.
Reviewed By: yota9
Differential Revision: https://reviews.llvm.org/D129168
