[compiler-rt] r298977 - [XRay][compiler-rt] Add an end-to-end test for FDR Logging

Evgenii Stepanov via llvm-commits llvm-commits at lists.llvm.org
Tue Apr 18 12:01:03 PDT 2017


Hi,

this test is reliably failing on the bots and on my desktop (x86_64).

__xray_FunctionExit:
        .cfi_startproc
        pushq   %rbp
        .cfi_def_cfa_offset 16
        subq    $56, %rsp
        .cfi_def_cfa_offset 32
        movupd  %xmm0, 40(%rsp)
        movupd  %xmm1, 24(%rsp)
        movq    %rax, 16(%rsp)
        movq    %rdx, 8(%rsp)
movq    _ZN6__xray19XRayPatchedFunctionE(%rip), %rax
        testq %rax,%rax
je      .Ltmp2

        movl    %r10d, %edi
        movl    $1, %esi
        callq   *%rax

This moves the stack pointer by 8 (pushq %rbp) + 56 + 8 (call *%rax) =
72 bytes. The callee gets an unaligned stack pointer.

The actual crash:
0x000000000041dae3 in readValueFromFile () at
/code/llvm/projects/compiler-rt/lib/xray/xray_x86_64.cc:43
43  char Line[BufSize] = {};
(gdb) bt
#0  0x000000000041dae3 in readValueFromFile () at
/code/llvm/projects/compiler-rt/lib/xray/xray_x86_64.cc:43
#1  0x000000000041da7b in __xray::getTSCFrequency() () at
/code/llvm/projects/compiler-rt/lib/xray/xray_x86_64.cc:65
#2  0x0000000000421789 in __xray::__xray_fdr_internal::thresholdTicks() ()
    at /code/llvm/projects/compiler-rt/lib/xray/xray_fdr_logging_impl.h:349
#3  0x0000000000420f65 in processFunctionHook () at
/code/llvm/projects/compiler-rt/lib/xray/xray_fdr_logging_impl.h:618
#4  fdrLoggingHandleArg0 () at
/code/llvm/projects/compiler-rt/lib/xray/xray_fdr_logging.cc:213
#5  0x000000000041de81 in __xray_FunctionExit () at
/code/llvm/projects/compiler-rt/lib/xray/xray_trampoline_x86_64.S:113
#6  0x0000000000000101 in ?? ()
#7  0x0000000000000000 in ?? ()

Dump of assembler code for function readValueFromFile():
   0x000000000041dab0 <+0>: push   %rbp
   0x000000000041dab1 <+1>: push   %r15
   0x000000000041dab3 <+3>: push   %r14
   0x000000000041dab5 <+5>: push   %rbx
   0x000000000041dab6 <+6>: sub    $0x118,%rsp
   0x000000000041dabd <+13>: mov    %rsi,%r14
   0x000000000041dac0 <+16>: xor    %ebx,%ebx
   0x000000000041dac2 <+18>: mov    $0x80000,%esi
   0x000000000041dac7 <+23>: xor    %eax,%eax
   0x000000000041dac9 <+25>: callq  0x4026b0 <open at plt>
   0x000000000041dace <+30>: mov    %eax,%r15d
   0x000000000041dad1 <+33>: cmp    $0xffffffff,%r15d
   0x000000000041dad5 <+37>: je     0x41dbee <readValueFromFile()+318>
   0x000000000041dadb <+43>: lea    0x10(%rsp),%rbx
   0x000000000041dae0 <+48>: xorps  %xmm0,%xmm0
=> 0x000000000041dae3 <+51>: movaps %xmm0,0x100(%rsp)
   0x000000000041daeb <+59>: movaps %xmm0,0xf0(%rsp)
   0x000000000041daf3 <+67>: movaps %xmm0,0xe0(%rsp)
   0x000000000041dafb <+75>: movaps %xmm0,0xd0(%rsp)

Also, as can be seen above, there is a stack unwinding issue (frame
#6). I'm not sure what's the problem there.


On Tue, Mar 28, 2017 at 10:19 PM, Dean Michael Berris via llvm-commits
<llvm-commits at lists.llvm.org> wrote:
> Author: dberris
> Date: Wed Mar 29 00:19:24 2017
> New Revision: 298977
>
> URL: http://llvm.org/viewvc/llvm-project?rev=298977&view=rev
> Log:
> [XRay][compiler-rt] Add an end-to-end test for FDR Logging
>
> Summary:
> This change exercises the end-to-end functionality defined in the FDR
> logging implementation. We also prepare for being able to run traces
> generated by the FDR logging implementation from being analysed with the
> llvm-xray command that comes with the LLVM distribution.
>
> This also unblocks D31385, D31384, and D31345.
>
> Reviewers: kpw, pelikan
>
> Subscribers: llvm-commits, mgorny
>
> Differential Revision: https://reviews.llvm.org/D31452
>
> Added:
>     compiler-rt/trunk/test/xray/TestCases/Linux/fdr-mode.cc
> Modified:
>     compiler-rt/trunk/include/CMakeLists.txt
>     compiler-rt/trunk/include/xray/xray_log_interface.h
>     compiler-rt/trunk/lib/xray/xray_fdr_logging.cc
>     compiler-rt/trunk/lib/xray/xray_fdr_logging.h
>     compiler-rt/trunk/lib/xray/xray_log_interface.cc
>     compiler-rt/trunk/lib/xray/xray_utils.cc
>     compiler-rt/trunk/test/xray/lit.cfg
>
> Modified: compiler-rt/trunk/include/CMakeLists.txt
> URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/include/CMakeLists.txt?rev=298977&r1=298976&r2=298977&view=diff
> ==============================================================================
> --- compiler-rt/trunk/include/CMakeLists.txt (original)
> +++ compiler-rt/trunk/include/CMakeLists.txt Wed Mar 29 00:19:24 2017
> @@ -12,7 +12,8 @@ set(SANITIZER_HEADERS
>    sanitizer/tsan_interface_atomic.h)
>
>  set(XRAY_HEADERS
> -  xray/xray_interface.h)
> +  xray/xray_interface.h
> +  xray/xray_log_interface.h)
>
>  set(COMPILER_RT_HEADERS
>    ${SANITIZER_HEADERS}
>
> Modified: compiler-rt/trunk/include/xray/xray_log_interface.h
> URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/include/xray/xray_log_interface.h?rev=298977&r1=298976&r2=298977&view=diff
> ==============================================================================
> --- compiler-rt/trunk/include/xray/xray_log_interface.h (original)
> +++ compiler-rt/trunk/include/xray/xray_log_interface.h Wed Mar 29 00:19:24 2017
> @@ -48,4 +48,13 @@ XRayLogFlushStatus __xray_log_flushLog()
>
>  } // extern "C"
>
> +namespace __xray {
> +// Options used by the LLVM XRay FDR implementation.
> +struct FDRLoggingOptions {
> +  bool ReportErrors = false;
> +  int Fd = -1;
> +};
> +
> +} // namespace __xray
> +
>  #endif // XRAY_XRAY_LOG_INTERFACE_H
>
> Modified: compiler-rt/trunk/lib/xray/xray_fdr_logging.cc
> URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/xray/xray_fdr_logging.cc?rev=298977&r1=298976&r2=298977&view=diff
> ==============================================================================
> --- compiler-rt/trunk/lib/xray/xray_fdr_logging.cc (original)
> +++ compiler-rt/trunk/lib/xray/xray_fdr_logging.cc Wed Mar 29 00:19:24 2017
> @@ -51,19 +51,18 @@ std::unique_ptr<FDRLoggingOptions> FDROp
>  XRayLogInitStatus fdrLoggingInit(std::size_t BufferSize, std::size_t BufferMax,
>                                   void *Options,
>                                   size_t OptionsSize) XRAY_NEVER_INSTRUMENT {
> -  assert(OptionsSize == sizeof(FDRLoggingOptions));
> +  if (OptionsSize != sizeof(FDRLoggingOptions))
> +    return static_cast<XRayLogInitStatus>(__sanitizer::atomic_load(
> +        &LoggingStatus, __sanitizer::memory_order_acquire));
>    s32 CurrentStatus = XRayLogInitStatus::XRAY_LOG_UNINITIALIZED;
> -  if (__sanitizer::atomic_compare_exchange_strong(
> +  if (!__sanitizer::atomic_compare_exchange_strong(
>            &LoggingStatus, &CurrentStatus,
>            XRayLogInitStatus::XRAY_LOG_INITIALIZING,
>            __sanitizer::memory_order_release))
>      return static_cast<XRayLogInitStatus>(CurrentStatus);
>
>    FDROptions.reset(new FDRLoggingOptions());
> -  *FDROptions = *reinterpret_cast<FDRLoggingOptions *>(Options);
> -  if (FDROptions->ReportErrors)
> -    SetPrintfAndReportCallback(printToStdErr);
> -
> +  memcpy(FDROptions.get(), Options, OptionsSize);
>    bool Success = false;
>    BQ = std::make_shared<BufferQueue>(BufferSize, BufferMax, Success);
>    if (!Success) {
> @@ -77,6 +76,7 @@ XRayLogInitStatus fdrLoggingInit(std::si
>    __sanitizer::atomic_store(&LoggingStatus,
>                              XRayLogInitStatus::XRAY_LOG_INITIALIZED,
>                              __sanitizer::memory_order_release);
> +  Report("XRay FDR init successful.\n");
>    return XRayLogInitStatus::XRAY_LOG_INITIALIZED;
>  }
>
> @@ -88,7 +88,7 @@ XRayLogFlushStatus fdrLoggingFlush() XRA
>      return XRayLogFlushStatus::XRAY_LOG_NOT_FLUSHING;
>
>    s32 Result = XRayLogFlushStatus::XRAY_LOG_NOT_FLUSHING;
> -  if (__sanitizer::atomic_compare_exchange_strong(
> +  if (!__sanitizer::atomic_compare_exchange_strong(
>            &LogFlushStatus, &Result, XRayLogFlushStatus::XRAY_LOG_FLUSHING,
>            __sanitizer::memory_order_release))
>      return static_cast<XRayLogFlushStatus>(Result);
> @@ -140,7 +140,7 @@ XRayLogFlushStatus fdrLoggingFlush() XRA
>
>  XRayLogInitStatus fdrLoggingFinalize() XRAY_NEVER_INSTRUMENT {
>    s32 CurrentStatus = XRayLogInitStatus::XRAY_LOG_INITIALIZED;
> -  if (__sanitizer::atomic_compare_exchange_strong(
> +  if (!__sanitizer::atomic_compare_exchange_strong(
>            &LoggingStatus, &CurrentStatus,
>            XRayLogInitStatus::XRAY_LOG_FINALIZING,
>            __sanitizer::memory_order_release))
> @@ -168,8 +168,7 @@ XRayLogInitStatus fdrLoggingReset() XRAY
>    BQ.reset();
>
>    // Spin until the flushing status is flushed.
> -  s32 CurrentFlushingStatus =
> -      XRayLogFlushStatus::XRAY_LOG_FLUSHED;
> +  s32 CurrentFlushingStatus = XRayLogFlushStatus::XRAY_LOG_FLUSHED;
>    while (__sanitizer::atomic_compare_exchange_weak(
>        &LogFlushStatus, &CurrentFlushingStatus,
>        XRayLogFlushStatus::XRAY_LOG_NOT_FLUSHING,
>
> Modified: compiler-rt/trunk/lib/xray/xray_fdr_logging.h
> URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/xray/xray_fdr_logging.h?rev=298977&r1=298976&r2=298977&view=diff
> ==============================================================================
> --- compiler-rt/trunk/lib/xray/xray_fdr_logging.h (original)
> +++ compiler-rt/trunk/lib/xray/xray_fdr_logging.h Wed Mar 29 00:19:24 2017
> @@ -26,14 +26,6 @@
>  // default mode of always writing fixed-size records.
>
>  namespace __xray {
> -
> -// Options used by the FDR implementation.
> -struct FDRLoggingOptions {
> -  bool ReportErrors = false;
> -  int Fd = -1;
> -};
> -
> -// Flight Data Recorder mode implementation interfaces.
>  XRayLogInitStatus fdrLoggingInit(size_t BufferSize, size_t BufferMax,
>                                   void *Options, size_t OptionsSize);
>  XRayLogInitStatus fdrLoggingFinalize();
>
> Modified: compiler-rt/trunk/lib/xray/xray_log_interface.cc
> URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/xray/xray_log_interface.cc?rev=298977&r1=298976&r2=298977&view=diff
> ==============================================================================
> --- compiler-rt/trunk/lib/xray/xray_log_interface.cc (original)
> +++ compiler-rt/trunk/lib/xray/xray_log_interface.cc Wed Mar 29 00:19:24 2017
> @@ -35,8 +35,9 @@ void __xray_set_log_impl(XRayLogImpl Imp
>    *GlobalXRayImpl = Impl;
>  }
>
> -XRayLogInitStatus __xray_init(size_t BufferSize, size_t MaxBuffers, void *Args,
> -                              size_t ArgsSize) XRAY_NEVER_INSTRUMENT {
> +XRayLogInitStatus __xray_log_init(size_t BufferSize, size_t MaxBuffers,
> +                                  void *Args,
> +                                  size_t ArgsSize) XRAY_NEVER_INSTRUMENT {
>    __sanitizer::SpinMutexLock Guard(&XRayImplMutex);
>    if (!GlobalXRayImpl)
>      return XRayLogInitStatus::XRAY_LOG_UNINITIALIZED;
>
> Modified: compiler-rt/trunk/lib/xray/xray_utils.cc
> URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/lib/xray/xray_utils.cc?rev=298977&r1=298976&r2=298977&view=diff
> ==============================================================================
> --- compiler-rt/trunk/lib/xray/xray_utils.cc (original)
> +++ compiler-rt/trunk/lib/xray/xray_utils.cc Wed Mar 29 00:19:24 2017
> @@ -93,8 +93,6 @@ bool readValueFromFile(const char *Filen
>  }
>
>  int getLogFD() XRAY_NEVER_INSTRUMENT {
> -  // FIXME: Figure out how to make this less stderr-dependent.
> -  SetPrintfAndReportCallback(printToStdErr);
>    // Open a temporary file once for the log.
>    static char TmpFilename[256] = {};
>    static char TmpWildcardPattern[] = "XXXXXX";
> @@ -119,8 +117,7 @@ int getLogFD() XRAY_NEVER_INSTRUMENT {
>             TmpFilename);
>      return -1;
>    }
> -  if (Verbosity())
> -    fprintf(stderr, "XRay: Log file in '%s'\n", TmpFilename);
> +  Report("XRay: Log file in '%s'\n", TmpFilename);
>
>    return Fd;
>  }
>
> Added: compiler-rt/trunk/test/xray/TestCases/Linux/fdr-mode.cc
> URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/test/xray/TestCases/Linux/fdr-mode.cc?rev=298977&view=auto
> ==============================================================================
> --- compiler-rt/trunk/test/xray/TestCases/Linux/fdr-mode.cc (added)
> +++ compiler-rt/trunk/test/xray/TestCases/Linux/fdr-mode.cc Wed Mar 29 00:19:24 2017
> @@ -0,0 +1,62 @@
> +// RUN: %clangxx_xray -std=c++11 %s -o %t
> +// RUN: XRAY_OPTIONS="patch_premain=false xray_naive_log=false xray_logfile_base=fdr-logging-test- xray_fdr_log=true verbosity=1" %run %t 2>&1 | FileCheck %s
> +// FIXME: %llvm_xray convert -instr_map=%t "`ls fdr-logging-test-* | head -1`" | FileCheck %s --check-prefix TRACE
> +// RUN: rm fdr-logging-test-*
> +
> +#include "xray/xray_log_interface.h"
> +#include <cassert>
> +#include <chrono>
> +#include <cstdio>
> +#include <iostream>
> +#include <stdlib.h>
> +#include <thread>
> +#include <time.h>
> +
> +constexpr auto kBufferSize = 16384;
> +constexpr auto kBufferMax = 10;
> +
> +thread_local uint64_t var = 0;
> +[[clang::xray_always_instrument]] void __attribute__((noinline)) fC() { ++var; }
> +
> +[[clang::xray_always_instrument]] void __attribute__((noinline)) fB() { fC(); }
> +
> +[[clang::xray_always_instrument]] void __attribute__((noinline)) fA() { fB(); }
> +
> +int main(int argc, char *argv[]) {
> +  using namespace __xray;
> +  FDRLoggingOptions Options;
> +  std::cout << "Logging before init." << std::endl;
> +  // CHECK: Logging before init.
> +  auto status = __xray_log_init(kBufferSize, kBufferMax, &Options,
> +                                sizeof(FDRLoggingOptions));
> +  assert(status == XRayLogInitStatus::XRAY_LOG_INITIALIZED);
> +  std::cout << "Init status " << status << std::endl;
> +  // CHECK: Init status {{.*}}
> +  std::cout << "Patching..." << std::endl;
> +  // CHECK: Patching...
> +  __xray_patch();
> +  fA();
> +  fC();
> +  fB();
> +  fA();
> +  fC();
> +  std::thread other_thread([]() {
> +    fC();
> +    fB();
> +    fA();
> +  });
> +  other_thread.join();
> +  std::cout << "Joined" << std::endl;
> +  // CHECK: Joined
> +  std::cout << "Finalize status " << __xray_log_finalize() << std::endl;
> +  // CHECK: Finalize status {{.*}}
> +  fC();
> +  std::cout << "Main execution var = " << var << std::endl;
> +  // CHECK: Main execution var = 6
> +  std::cout << "Flush status " << __xray_log_flushLog() << std::endl;
> +  // CHECK: Flush status {{.*}}
> +  __xray_unpatch();
> +  return 0;
> +}
> +
> +// TRACE: { function }
>
> Modified: compiler-rt/trunk/test/xray/lit.cfg
> URL: http://llvm.org/viewvc/llvm-project/compiler-rt/trunk/test/xray/lit.cfg?rev=298977&r1=298976&r2=298977&view=diff
> ==============================================================================
> --- compiler-rt/trunk/test/xray/lit.cfg (original)
> +++ compiler-rt/trunk/test/xray/lit.cfg Wed Mar 29 00:19:24 2017
> @@ -16,6 +16,9 @@ clang_xray_cxxflags = config.cxx_mode_fl
>  def build_invocation(compile_flags):
>    return ' ' + ' '.join([config.clang] + compile_flags) + ' '
>
> +# Assume that llvm-xray is in the config.llvm_tools_dir.
> +llvm_xray = os.path.join(config.llvm_tools_dir, 'llvm-xray')
> +
>  # Setup substitutions.
>  config.substitutions.append(
>      ('%clang ', build_invocation([config.target_cflags])))
> @@ -26,6 +29,8 @@ config.substitutions.append(
>      ('%clang_xray ', build_invocation(clang_xray_cflags)))
>  config.substitutions.append(
>      ('%clangxx_xray', build_invocation(clang_xray_cxxflags)))
> +config.substitutions.append(
> +    ('%llvm_xray', llvm_xray))
>
>  # Default test suffixes.
>  config.suffixes = ['.c', '.cc', '.cpp']
>
>
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