compiler-rt/lib/profile/InstrProfilingMerge.c

   1 /*===- InstrProfilingMerge.c - Profile in-process Merging  ---------------===*\
   2 |*
   3 |* Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 |* See https://llvm.org/LICENSE.txt for license information.
   5 |* SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 |*
   7 |*===----------------------------------------------------------------------===*
   8 |* This file defines the API needed for in-process merging of profile data
   9 |* stored in memory buffer.
  10 \*===---------------------------------------------------------------------===*/
  11
  12 #include "InstrProfiling.h"
  13 #include "InstrProfilingInternal.h"
  14 #include "InstrProfilingUtil.h"
  15
  16 #define INSTR_PROF_VALUE_PROF_DATA
  17 #include "profile/InstrProfData.inc"
  18
  19 COMPILER_RT_VISIBILITY
  20 void (*VPMergeHook)(ValueProfData *, __llvm_profile_data *);
  21
  22 COMPILER_RT_VISIBILITY
  23 uint64_t lprofGetLoadModuleSignature(void) {
  24   /* A very fast way to compute a module signature.  */
  25   uint64_t Version = __llvm_profile_get_version();
  26   uint64_t NumCounters = __llvm_profile_get_num_counters(
  27       __llvm_profile_begin_counters(), __llvm_profile_end_counters());
  28   uint64_t NumData = __llvm_profile_get_num_data(__llvm_profile_begin_data(),
  29                                                  __llvm_profile_end_data());
  30   uint64_t NamesSize =
  31       (uint64_t)(__llvm_profile_end_names() - __llvm_profile_begin_names());
  32   uint64_t NumVnodes =
  33       (uint64_t)(__llvm_profile_end_vnodes() - __llvm_profile_begin_vnodes());
  34   const __llvm_profile_data *FirstD = __llvm_profile_begin_data();
  35
  36   return (NamesSize << 40) + (NumCounters << 30) + (NumData << 20) +
  37          (NumVnodes << 10) + (NumData > 0 ? FirstD->NameRef : 0) + Version +
  38          __llvm_profile_get_magic();
  39 }
  40
  41 /* Returns 1 if profile is not structurally compatible.  */
  42 COMPILER_RT_VISIBILITY
  43 int __llvm_profile_check_compatibility(const char *ProfileData,
  44                                        uint64_t ProfileSize) {
  45   /* Check profile header only for now  */
  46   __llvm_profile_header *Header = (__llvm_profile_header *)ProfileData;
  47   __llvm_profile_data *SrcDataStart, *SrcDataEnd, *SrcData, *DstData;
  48   SrcDataStart =
  49       (__llvm_profile_data *)(ProfileData + sizeof(__llvm_profile_header) +
  50                               Header->BinaryIdsSize);
  51   SrcDataEnd = SrcDataStart + Header->DataSize;
  52
  53   if (ProfileSize < sizeof(__llvm_profile_header))
  54     return 1;
  55
  56   /* Check the header first.  */
  57   if (Header->Magic != __llvm_profile_get_magic() ||
  58       Header->Version != __llvm_profile_get_version() ||
  59       Header->DataSize !=
  60           __llvm_profile_get_num_data(__llvm_profile_begin_data(),
  61                                       __llvm_profile_end_data()) ||
  62       Header->CountersSize !=
  63           __llvm_profile_get_num_counters(__llvm_profile_begin_counters(),
  64                                           __llvm_profile_end_counters()) ||
  65       Header->NamesSize != (uint64_t)(__llvm_profile_end_names() -
  66                                       __llvm_profile_begin_names()) ||
  67       Header->ValueKindLast != IPVK_Last)
  68     return 1;
  69
  70   if (ProfileSize <
  71       sizeof(__llvm_profile_header) + Header->BinaryIdsSize +
  72           Header->DataSize * sizeof(__llvm_profile_data) + Header->NamesSize +
  73           Header->CountersSize * __llvm_profile_counter_entry_size())
  74     return 1;
  75
  76   for (SrcData = SrcDataStart,
  77        DstData = (__llvm_profile_data *)__llvm_profile_begin_data();
  78        SrcData < SrcDataEnd; ++SrcData, ++DstData) {
  79     if (SrcData->NameRef != DstData->NameRef ||
  80         SrcData->FuncHash != DstData->FuncHash ||
  81         SrcData->NumCounters != DstData->NumCounters)
  82       return 1;
  83   }
  84
  85   /* Matched! */
  86   return 0;
  87 }
  88
  89 static uintptr_t signextIfWin64(void *V) {
  90 #ifdef _WIN64
  91   return (uintptr_t)(int32_t)(uintptr_t)V;
  92 #else
  93   return (uintptr_t)V;
  94 #endif
  95 }
  96
  97 COMPILER_RT_VISIBILITY
  98 int __llvm_profile_merge_from_buffer(const char *ProfileData,
  99                                      uint64_t ProfileSize) {
 100   if (__llvm_profile_get_version() & VARIANT_MASK_DBG_CORRELATE) {
 101     PROF_ERR(
 102         "%s\n",
 103         "Debug info correlation does not support profile merging at runtime. "
 104         "Instead, merge raw profiles using the llvm-profdata tool.");
 105     return 1;
 106   }
 107
 108   __llvm_profile_data *SrcDataStart, *SrcDataEnd, *SrcData, *DstData;
 109   __llvm_profile_header *Header = (__llvm_profile_header *)ProfileData;
 110   char *SrcCountersStart;
 111   const char *SrcNameStart;
 112   const char *SrcValueProfDataStart, *SrcValueProfData;
 113   uintptr_t CountersDelta = Header->CountersDelta;
 114
 115   SrcDataStart =
 116       (__llvm_profile_data *)(ProfileData + sizeof(__llvm_profile_header) +
 117                               Header->BinaryIdsSize);
 118   SrcDataEnd = SrcDataStart + Header->DataSize;
 119   SrcCountersStart = (char *)SrcDataEnd;
 120   SrcNameStart = SrcCountersStart +
 121                  Header->CountersSize * __llvm_profile_counter_entry_size();
 122   SrcValueProfDataStart =
 123       SrcNameStart + Header->NamesSize +
 124       __llvm_profile_get_num_padding_bytes(Header->NamesSize);
 125   if (SrcNameStart < SrcCountersStart)
 126     return 1;
 127
 128   for (SrcData = SrcDataStart,
 129       DstData = (__llvm_profile_data *)__llvm_profile_begin_data(),
 130       SrcValueProfData = SrcValueProfDataStart;
 131        SrcData < SrcDataEnd; ++SrcData, ++DstData) {
 132     // For the in-memory destination, CounterPtr is the distance from the start
 133     // address of the data to the start address of the counter. On WIN64,
 134     // CounterPtr is a truncated 32-bit value due to COFF limitation. Sign
 135     // extend CounterPtr to get the original value.
 136     char *DstCounters =
 137         (char *)((uintptr_t)DstData + signextIfWin64(DstData->CounterPtr));
 138     unsigned NVK = 0;
 139
 140     // SrcData is a serialized representation of the memory image. We need to
 141     // compute the in-buffer counter offset from the in-memory address distance.
 142     // The initial CountersDelta is the in-memory address difference
 143     // start(__llvm_prf_cnts)-start(__llvm_prf_data), so SrcData->CounterPtr -
 144     // CountersDelta computes the offset into the in-buffer counter section.
 145     //
 146     // On WIN64, CountersDelta is truncated as well, so no need for signext.
 147     char *SrcCounters =
 148         SrcCountersStart + ((uintptr_t)SrcData->CounterPtr - CountersDelta);
 149     // CountersDelta needs to be decreased as we advance to the next data
 150     // record.
 151     CountersDelta -= sizeof(*SrcData);
 152     unsigned NC = SrcData->NumCounters;
 153     if (NC == 0)
 154       return 1;
 155     if (SrcCounters < SrcCountersStart || SrcCounters >= SrcNameStart ||
 156         (SrcCounters + __llvm_profile_counter_entry_size() * NC) > SrcNameStart)
 157       return 1;
 158     for (unsigned I = 0; I < NC; I++) {
 159       if (__llvm_profile_get_version() & VARIANT_MASK_BYTE_COVERAGE) {
 160         // A value of zero signifies the function is covered.
 161         DstCounters[I] &= SrcCounters[I];
 162       } else {
 163         ((uint64_t *)DstCounters)[I] += ((uint64_t *)SrcCounters)[I];
 164       }
 165     }
 166
 167     /* Now merge value profile data. */
 168     if (!VPMergeHook)
 169       continue;
 170
 171     for (unsigned I = 0; I <= IPVK_Last; I++)
 172       NVK += (SrcData->NumValueSites[I] != 0);
 173
 174     if (!NVK)
 175       continue;
 176
 177     if (SrcValueProfData >= ProfileData + ProfileSize)
 178       return 1;
 179     VPMergeHook((ValueProfData *)SrcValueProfData, DstData);
 180     SrcValueProfData =
 181         SrcValueProfData + ((ValueProfData *)SrcValueProfData)->TotalSize;
 182   }
 183
 184   return 0;
 185 }