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1/*===- InstrProfilingPlatformFuchsia.c - Profile data Fuchsia platform ----===*\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-exception6|*7\*===----------------------------------------------------------------------===*/8/*9 * This file implements the profiling runtime for Fuchsia and defines the10 * shared profile runtime interface. Each module (executable or DSO) statically11 * links in the whole profile runtime to satisfy the calls from its12 * instrumented code. Several modules in the same program might be separately13 * compiled and even use different versions of the instrumentation ABI and data14 * format. All they share in common is the VMO and the offset, which live in15 * exported globals so that exactly one definition will be shared across all16 * modules. Each module has its own independent runtime that registers its own17 * atexit hook to append its own data into the shared VMO which is published18 * via the data sink hook provided by Fuchsia's dynamic linker.19 */20 21#if defined(__Fuchsia__)22 23#include <inttypes.h>24#include <stdarg.h>25#include <stdbool.h>26#include <stdlib.h>27 28#include <zircon/process.h>29#include <zircon/sanitizer.h>30#include <zircon/status.h>31#include <zircon/syscalls.h>32 33#include "InstrProfiling.h"34#include "InstrProfilingInternal.h"35#include "InstrProfilingUtil.h"36 37/* This variable is an external reference to symbol defined by the compiler. */38COMPILER_RT_VISIBILITY extern int64_t INSTR_PROF_PROFILE_COUNTER_BIAS_VAR;39 40COMPILER_RT_VISIBILITY unsigned lprofProfileDumped(void) {41 return 1;42}43COMPILER_RT_VISIBILITY void lprofSetProfileDumped(unsigned Value) {}44 45static const char ProfileSinkName[] = "llvm-profile";46 47static inline void lprofWrite(const char *fmt, ...) {48 char s[256];49 50 va_list ap;51 va_start(ap, fmt);52 int ret = vsnprintf(s, sizeof(s), fmt, ap);53 va_end(ap);54 55 __sanitizer_log_write(s, ret);56}57 58struct lprofVMOWriterCtx {59 /* VMO that contains the profile data for this module. */60 zx_handle_t Vmo;61 /* Current offset within the VMO where data should be written next. */62 uint64_t Offset;63};64 65static uint32_t lprofVMOWriter(ProfDataWriter *This, ProfDataIOVec *IOVecs,66 uint32_t NumIOVecs) {67 struct lprofVMOWriterCtx *Ctx = (struct lprofVMOWriterCtx *)This->WriterCtx;68 69 /* Compute the total length of data to be written. */70 size_t Length = 0;71 for (uint32_t I = 0; I < NumIOVecs; I++)72 Length += IOVecs[I].ElmSize * IOVecs[I].NumElm;73 74 /* Resize the VMO to ensure there's sufficient space for the data. */75 zx_status_t Status = _zx_vmo_set_size(Ctx->Vmo, Ctx->Offset + Length);76 if (Status != ZX_OK)77 return -1;78 79 /* Copy the data into VMO. */80 for (uint32_t I = 0; I < NumIOVecs; I++) {81 size_t Length = IOVecs[I].ElmSize * IOVecs[I].NumElm;82 if (IOVecs[I].Data) {83 Status = _zx_vmo_write(Ctx->Vmo, IOVecs[I].Data, Ctx->Offset, Length);84 if (Status != ZX_OK)85 return -1;86 } else if (IOVecs[I].UseZeroPadding) {87 /* Resizing the VMO should zero fill. */88 }89 Ctx->Offset += Length;90 }91 92 /* Record the profile size as a property of the VMO. */93 _zx_object_set_property(Ctx->Vmo, ZX_PROP_VMO_CONTENT_SIZE, &Ctx->Offset,94 sizeof(Ctx->Offset));95 96 return 0;97}98 99static void initVMOWriter(ProfDataWriter *This, struct lprofVMOWriterCtx *Ctx) {100 This->Write = lprofVMOWriter;101 This->WriterCtx = Ctx;102}103 104/* This method is invoked by the runtime initialization hook105 * InstrProfilingRuntime.o if it is linked in. */106COMPILER_RT_VISIBILITY107void __llvm_profile_initialize(void) {108 /* Check if there is llvm/runtime version mismatch. */109 if (GET_VERSION(__llvm_profile_get_version()) != INSTR_PROF_RAW_VERSION) {110 lprofWrite("LLVM Profile: runtime and instrumentation version mismatch: "111 "expected %d, but got %d\n",112 INSTR_PROF_RAW_VERSION,113 (int)GET_VERSION(__llvm_profile_get_version()));114 return;115 }116 117 const __llvm_profile_data *DataBegin = __llvm_profile_begin_data();118 const __llvm_profile_data *DataEnd = __llvm_profile_end_data();119 const char *CountersBegin = __llvm_profile_begin_counters();120 const char *CountersEnd = __llvm_profile_end_counters();121 const uint64_t DataSize = __llvm_profile_get_data_size(DataBegin, DataEnd);122 const uint64_t CountersOffset =123 sizeof(__llvm_profile_header) + __llvm_write_binary_ids(NULL) + DataSize;124 uint64_t CountersSize =125 __llvm_profile_get_counters_size(CountersBegin, CountersEnd);126 127 /* Don't publish a VMO if there are no counters. */128 if (!CountersSize)129 return;130 131 zx_status_t Status;132 133 /* Create a VMO to hold the profile data. */134 zx_handle_t Vmo = ZX_HANDLE_INVALID;135 Status = _zx_vmo_create(0, ZX_VMO_RESIZABLE, &Vmo);136 if (Status != ZX_OK) {137 lprofWrite("LLVM Profile: cannot create VMO: %s\n",138 _zx_status_get_string(Status));139 return;140 }141 142 /* Give the VMO a name that includes the module signature. */143 char VmoName[ZX_MAX_NAME_LEN];144 snprintf(VmoName, sizeof(VmoName), "%" PRIu64 ".profraw",145 lprofGetLoadModuleSignature());146 _zx_object_set_property(Vmo, ZX_PROP_NAME, VmoName, strlen(VmoName));147 148 /* Write the profile data into the mapped region. */149 ProfDataWriter VMOWriter;150 struct lprofVMOWriterCtx Ctx = {.Vmo = Vmo, .Offset = 0};151 initVMOWriter(&VMOWriter, &Ctx);152 if (lprofWriteData(&VMOWriter, 0, 0) != 0) {153 lprofWrite("LLVM Profile: failed to write data\n");154 _zx_handle_close(Vmo);155 return;156 }157 158 uint64_t Len = 0;159 Status = _zx_vmo_get_size(Vmo, &Len);160 if (Status != ZX_OK) {161 lprofWrite("LLVM Profile: failed to get the VMO size: %s\n",162 _zx_status_get_string(Status));163 _zx_handle_close(Vmo);164 return;165 }166 167 uintptr_t Mapping;168 Status =169 _zx_vmar_map(_zx_vmar_root_self(), ZX_VM_PERM_READ | ZX_VM_PERM_WRITE, 0,170 Vmo, 0, Len, &Mapping);171 if (Status != ZX_OK) {172 lprofWrite("LLVM Profile: failed to map the VMO: %s\n",173 _zx_status_get_string(Status));174 _zx_handle_close(Vmo);175 return;176 }177 178 /* Publish the VMO which contains profile data to the system. Note that this179 * also consumes the VMO handle. */180 __sanitizer_publish_data(ProfileSinkName, Vmo);181 182 /* Update the profile fields based on the current mapping. */183 INSTR_PROF_PROFILE_COUNTER_BIAS_VAR =184 (intptr_t)Mapping - (uintptr_t)CountersBegin + CountersOffset;185 186 /* Return the memory allocated for counters to OS. */187 lprofReleaseMemoryPagesToOS((uintptr_t)CountersBegin, (uintptr_t)CountersEnd);188}189 190#endif191