llvm-project/compiler-rt/lib/profile/InstrProfilingFile.c
Petr Hosek 47e5fcba57 [profile] Support profiling runtime on Fuchsia
This ports the profiling runtime on Fuchsia and enables the
instrumentation. Unlike on other platforms, Fuchsia doesn't use
files to dump the instrumentation data since on Fuchsia, filesystem
may not be accessible to the instrumented process. We instead use
the data sink to pass the profiling data to the system the same
sanitizer runtimes do.

Differential Revision: https://reviews.llvm.org/D47208

llvm-svn: 337881
2018-07-25 03:01:35 +00:00

668 lines
21 KiB
C

/*===- InstrProfilingFile.c - Write instrumentation to a file -------------===*\
|*
|* The LLVM Compiler Infrastructure
|*
|* This file is distributed under the University of Illinois Open Source
|* License. See LICENSE.TXT for details.
|*
\*===----------------------------------------------------------------------===*/
#if !defined(__Fuchsia__)
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#ifdef _MSC_VER
/* For _alloca. */
#include <malloc.h>
#endif
#if defined(_WIN32)
#include "WindowsMMap.h"
/* For _chsize_s */
#include <io.h>
#include <process.h>
#else
#include <sys/file.h>
#include <sys/mman.h>
#include <unistd.h>
#if defined(__linux__)
#include <sys/types.h>
#endif
#endif
#include "InstrProfiling.h"
#include "InstrProfilingInternal.h"
#include "InstrProfilingUtil.h"
/* From where is profile name specified.
* The order the enumerators define their
* precedence. Re-order them may lead to
* runtime behavior change. */
typedef enum ProfileNameSpecifier {
PNS_unknown = 0,
PNS_default,
PNS_command_line,
PNS_environment,
PNS_runtime_api
} ProfileNameSpecifier;
static const char *getPNSStr(ProfileNameSpecifier PNS) {
switch (PNS) {
case PNS_default:
return "default setting";
case PNS_command_line:
return "command line";
case PNS_environment:
return "environment variable";
case PNS_runtime_api:
return "runtime API";
default:
return "Unknown";
}
}
#define MAX_PID_SIZE 16
/* Data structure holding the result of parsed filename pattern. */
typedef struct lprofFilename {
/* File name string possibly with %p or %h specifiers. */
const char *FilenamePat;
/* A flag indicating if FilenamePat's memory is allocated
* by runtime. */
unsigned OwnsFilenamePat;
const char *ProfilePathPrefix;
const char *Filename;
char PidChars[MAX_PID_SIZE];
char Hostname[COMPILER_RT_MAX_HOSTLEN];
unsigned NumPids;
unsigned NumHosts;
/* When in-process merging is enabled, this parameter specifies
* the total number of profile data files shared by all the processes
* spawned from the same binary. By default the value is 1. If merging
* is not enabled, its value should be 0. This parameter is specified
* by the %[0-9]m specifier. For instance %2m enables merging using
* 2 profile data files. %1m is equivalent to %m. Also %m specifier
* can only appear once at the end of the name pattern. */
unsigned MergePoolSize;
ProfileNameSpecifier PNS;
} lprofFilename;
COMPILER_RT_WEAK lprofFilename lprofCurFilename = {0, 0, 0, 0, {0},
{0}, 0, 0, 0, PNS_unknown};
static int getCurFilenameLength();
static const char *getCurFilename(char *FilenameBuf, int ForceUseBuf);
static unsigned doMerging() { return lprofCurFilename.MergePoolSize; }
/* Return 1 if there is an error, otherwise return 0. */
static uint32_t fileWriter(ProfDataWriter *This, ProfDataIOVec *IOVecs,
uint32_t NumIOVecs) {
uint32_t I;
FILE *File = (FILE *)This->WriterCtx;
for (I = 0; I < NumIOVecs; I++) {
if (IOVecs[I].Data) {
if (fwrite(IOVecs[I].Data, IOVecs[I].ElmSize, IOVecs[I].NumElm, File) !=
IOVecs[I].NumElm)
return 1;
} else {
if (fseek(File, IOVecs[I].ElmSize * IOVecs[I].NumElm, SEEK_CUR) == -1)
return 1;
}
}
return 0;
}
static void initFileWriter(ProfDataWriter *This, FILE *File) {
This->Write = fileWriter;
This->WriterCtx = File;
}
COMPILER_RT_VISIBILITY ProfBufferIO *
lprofCreateBufferIOInternal(void *File, uint32_t BufferSz) {
FreeHook = &free;
DynamicBufferIOBuffer = (uint8_t *)calloc(BufferSz, 1);
VPBufferSize = BufferSz;
ProfDataWriter *fileWriter =
(ProfDataWriter *)calloc(sizeof(ProfDataWriter), 1);
initFileWriter(fileWriter, File);
ProfBufferIO *IO = lprofCreateBufferIO(fileWriter);
IO->OwnFileWriter = 1;
return IO;
}
static void setupIOBuffer() {
const char *BufferSzStr = 0;
BufferSzStr = getenv("LLVM_VP_BUFFER_SIZE");
if (BufferSzStr && BufferSzStr[0]) {
VPBufferSize = atoi(BufferSzStr);
DynamicBufferIOBuffer = (uint8_t *)calloc(VPBufferSize, 1);
}
}
/* Read profile data in \c ProfileFile and merge with in-memory
profile counters. Returns -1 if there is fatal error, otheriwse
0 is returned. Returning 0 does not mean merge is actually
performed. If merge is actually done, *MergeDone is set to 1.
*/
static int doProfileMerging(FILE *ProfileFile, int *MergeDone) {
uint64_t ProfileFileSize;
char *ProfileBuffer;
if (fseek(ProfileFile, 0L, SEEK_END) == -1) {
PROF_ERR("Unable to merge profile data, unable to get size: %s\n",
strerror(errno));
return -1;
}
ProfileFileSize = ftell(ProfileFile);
/* Restore file offset. */
if (fseek(ProfileFile, 0L, SEEK_SET) == -1) {
PROF_ERR("Unable to merge profile data, unable to rewind: %s\n",
strerror(errno));
return -1;
}
/* Nothing to merge. */
if (ProfileFileSize < sizeof(__llvm_profile_header)) {
if (ProfileFileSize)
PROF_WARN("Unable to merge profile data: %s\n",
"source profile file is too small.");
return 0;
}
ProfileBuffer = mmap(NULL, ProfileFileSize, PROT_READ, MAP_SHARED | MAP_FILE,
fileno(ProfileFile), 0);
if (ProfileBuffer == MAP_FAILED) {
PROF_ERR("Unable to merge profile data, mmap failed: %s\n",
strerror(errno));
return -1;
}
if (__llvm_profile_check_compatibility(ProfileBuffer, ProfileFileSize)) {
(void)munmap(ProfileBuffer, ProfileFileSize);
PROF_WARN("Unable to merge profile data: %s\n",
"source profile file is not compatible.");
return 0;
}
/* Now start merging */
__llvm_profile_merge_from_buffer(ProfileBuffer, ProfileFileSize);
// Truncate the file in case merging of value profile did not happend to
// prevent from leaving garbage data at the end of the profile file.
COMPILER_RT_FTRUNCATE(ProfileFile, __llvm_profile_get_size_for_buffer());
(void)munmap(ProfileBuffer, ProfileFileSize);
*MergeDone = 1;
return 0;
}
/* Create the directory holding the file, if needed. */
static void createProfileDir(const char *Filename) {
size_t Length = strlen(Filename);
if (lprofFindFirstDirSeparator(Filename)) {
char *Copy = (char *)COMPILER_RT_ALLOCA(Length + 1);
strncpy(Copy, Filename, Length + 1);
__llvm_profile_recursive_mkdir(Copy);
}
}
/* Open the profile data for merging. It opens the file in r+b mode with
* file locking. If the file has content which is compatible with the
* current process, it also reads in the profile data in the file and merge
* it with in-memory counters. After the profile data is merged in memory,
* the original profile data is truncated and gets ready for the profile
* dumper. With profile merging enabled, each executable as well as any of
* its instrumented shared libraries dump profile data into their own data file.
*/
static FILE *openFileForMerging(const char *ProfileFileName, int *MergeDone) {
FILE *ProfileFile;
int rc;
createProfileDir(ProfileFileName);
ProfileFile = lprofOpenFileEx(ProfileFileName);
if (!ProfileFile)
return NULL;
rc = doProfileMerging(ProfileFile, MergeDone);
if (rc || (!*MergeDone && COMPILER_RT_FTRUNCATE(ProfileFile, 0L)) ||
fseek(ProfileFile, 0L, SEEK_SET) == -1) {
PROF_ERR("Profile Merging of file %s failed: %s\n", ProfileFileName,
strerror(errno));
fclose(ProfileFile);
return NULL;
}
return ProfileFile;
}
/* Write profile data to file \c OutputName. */
static int writeFile(const char *OutputName) {
int RetVal;
FILE *OutputFile;
int MergeDone = 0;
VPMergeHook = &lprofMergeValueProfData;
if (!doMerging())
OutputFile = fopen(OutputName, "ab");
else
OutputFile = openFileForMerging(OutputName, &MergeDone);
if (!OutputFile)
return -1;
FreeHook = &free;
setupIOBuffer();
ProfDataWriter fileWriter;
initFileWriter(&fileWriter, OutputFile);
RetVal = lprofWriteData(&fileWriter, lprofGetVPDataReader(), MergeDone);
fclose(OutputFile);
return RetVal;
}
static void truncateCurrentFile(void) {
const char *Filename;
char *FilenameBuf;
FILE *File;
int Length;
Length = getCurFilenameLength();
FilenameBuf = (char *)COMPILER_RT_ALLOCA(Length + 1);
Filename = getCurFilename(FilenameBuf, 0);
if (!Filename)
return;
/* By pass file truncation to allow online raw profile
* merging. */
if (lprofCurFilename.MergePoolSize)
return;
createProfileDir(Filename);
/* Truncate the file. Later we'll reopen and append. */
File = fopen(Filename, "w");
if (!File)
return;
fclose(File);
}
static const char *DefaultProfileName = "default.profraw";
static void resetFilenameToDefault(void) {
if (lprofCurFilename.FilenamePat && lprofCurFilename.OwnsFilenamePat) {
free((void *)lprofCurFilename.FilenamePat);
}
memset(&lprofCurFilename, 0, sizeof(lprofCurFilename));
lprofCurFilename.FilenamePat = DefaultProfileName;
lprofCurFilename.PNS = PNS_default;
}
static int containsMergeSpecifier(const char *FilenamePat, int I) {
return (FilenamePat[I] == 'm' ||
(FilenamePat[I] >= '1' && FilenamePat[I] <= '9' &&
/* If FilenamePat[I] is not '\0', the next byte is guaranteed
* to be in-bound as the string is null terminated. */
FilenamePat[I + 1] == 'm'));
}
/* Parses the pattern string \p FilenamePat and stores the result to
* lprofcurFilename structure. */
static int parseFilenamePattern(const char *FilenamePat,
unsigned CopyFilenamePat) {
int NumPids = 0, NumHosts = 0, I;
char *PidChars = &lprofCurFilename.PidChars[0];
char *Hostname = &lprofCurFilename.Hostname[0];
int MergingEnabled = 0;
/* Clean up cached prefix and filename. */
if (lprofCurFilename.ProfilePathPrefix)
free((void *)lprofCurFilename.ProfilePathPrefix);
if (lprofCurFilename.Filename)
free((void *)lprofCurFilename.Filename);
if (lprofCurFilename.FilenamePat && lprofCurFilename.OwnsFilenamePat) {
free((void *)lprofCurFilename.FilenamePat);
}
memset(&lprofCurFilename, 0, sizeof(lprofCurFilename));
if (!CopyFilenamePat)
lprofCurFilename.FilenamePat = FilenamePat;
else {
lprofCurFilename.FilenamePat = strdup(FilenamePat);
lprofCurFilename.OwnsFilenamePat = 1;
}
/* Check the filename for "%p", which indicates a pid-substitution. */
for (I = 0; FilenamePat[I]; ++I)
if (FilenamePat[I] == '%') {
if (FilenamePat[++I] == 'p') {
if (!NumPids++) {
if (snprintf(PidChars, MAX_PID_SIZE, "%ld", (long)getpid()) <= 0) {
PROF_WARN("Unable to get pid for filename pattern %s. Using the "
"default name.",
FilenamePat);
return -1;
}
}
} else if (FilenamePat[I] == 'h') {
if (!NumHosts++)
if (COMPILER_RT_GETHOSTNAME(Hostname, COMPILER_RT_MAX_HOSTLEN)) {
PROF_WARN("Unable to get hostname for filename pattern %s. Using "
"the default name.",
FilenamePat);
return -1;
}
} else if (containsMergeSpecifier(FilenamePat, I)) {
if (MergingEnabled) {
PROF_WARN("%%m specifier can only be specified once in %s.\n",
FilenamePat);
return -1;
}
MergingEnabled = 1;
if (FilenamePat[I] == 'm')
lprofCurFilename.MergePoolSize = 1;
else {
lprofCurFilename.MergePoolSize = FilenamePat[I] - '0';
I++; /* advance to 'm' */
}
}
}
lprofCurFilename.NumPids = NumPids;
lprofCurFilename.NumHosts = NumHosts;
return 0;
}
static void parseAndSetFilename(const char *FilenamePat,
ProfileNameSpecifier PNS,
unsigned CopyFilenamePat) {
const char *OldFilenamePat = lprofCurFilename.FilenamePat;
ProfileNameSpecifier OldPNS = lprofCurFilename.PNS;
if (PNS < OldPNS)
return;
if (!FilenamePat)
FilenamePat = DefaultProfileName;
if (OldFilenamePat && !strcmp(OldFilenamePat, FilenamePat)) {
lprofCurFilename.PNS = PNS;
return;
}
/* When PNS >= OldPNS, the last one wins. */
if (!FilenamePat || parseFilenamePattern(FilenamePat, CopyFilenamePat))
resetFilenameToDefault();
lprofCurFilename.PNS = PNS;
if (!OldFilenamePat) {
if (getenv("LLVM_PROFILE_VERBOSE"))
PROF_NOTE("Set profile file path to \"%s\" via %s.\n",
lprofCurFilename.FilenamePat, getPNSStr(PNS));
} else {
if (getenv("LLVM_PROFILE_VERBOSE"))
PROF_NOTE("Override old profile path \"%s\" via %s to \"%s\" via %s.\n",
OldFilenamePat, getPNSStr(OldPNS), lprofCurFilename.FilenamePat,
getPNSStr(PNS));
}
truncateCurrentFile();
}
/* Return buffer length that is required to store the current profile
* filename with PID and hostname substitutions. */
/* The length to hold uint64_t followed by 2 digit pool id including '_' */
#define SIGLEN 24
static int getCurFilenameLength() {
int Len;
if (!lprofCurFilename.FilenamePat || !lprofCurFilename.FilenamePat[0])
return 0;
if (!(lprofCurFilename.NumPids || lprofCurFilename.NumHosts ||
lprofCurFilename.MergePoolSize))
return strlen(lprofCurFilename.FilenamePat);
Len = strlen(lprofCurFilename.FilenamePat) +
lprofCurFilename.NumPids * (strlen(lprofCurFilename.PidChars) - 2) +
lprofCurFilename.NumHosts * (strlen(lprofCurFilename.Hostname) - 2);
if (lprofCurFilename.MergePoolSize)
Len += SIGLEN;
return Len;
}
/* Return the pointer to the current profile file name (after substituting
* PIDs and Hostnames in filename pattern. \p FilenameBuf is the buffer
* to store the resulting filename. If no substitution is needed, the
* current filename pattern string is directly returned, unless ForceUseBuf
* is enabled. */
static const char *getCurFilename(char *FilenameBuf, int ForceUseBuf) {
int I, J, PidLength, HostNameLength, FilenamePatLength;
const char *FilenamePat = lprofCurFilename.FilenamePat;
if (!lprofCurFilename.FilenamePat || !lprofCurFilename.FilenamePat[0])
return 0;
if (!(lprofCurFilename.NumPids || lprofCurFilename.NumHosts ||
lprofCurFilename.MergePoolSize)) {
if (!ForceUseBuf)
return lprofCurFilename.FilenamePat;
FilenamePatLength = strlen(lprofCurFilename.FilenamePat);
memcpy(FilenameBuf, lprofCurFilename.FilenamePat, FilenamePatLength);
FilenameBuf[FilenamePatLength] = '\0';
return FilenameBuf;
}
PidLength = strlen(lprofCurFilename.PidChars);
HostNameLength = strlen(lprofCurFilename.Hostname);
/* Construct the new filename. */
for (I = 0, J = 0; FilenamePat[I]; ++I)
if (FilenamePat[I] == '%') {
if (FilenamePat[++I] == 'p') {
memcpy(FilenameBuf + J, lprofCurFilename.PidChars, PidLength);
J += PidLength;
} else if (FilenamePat[I] == 'h') {
memcpy(FilenameBuf + J, lprofCurFilename.Hostname, HostNameLength);
J += HostNameLength;
} else if (containsMergeSpecifier(FilenamePat, I)) {
char LoadModuleSignature[SIGLEN];
int S;
int ProfilePoolId = getpid() % lprofCurFilename.MergePoolSize;
S = snprintf(LoadModuleSignature, SIGLEN, "%" PRIu64 "_%d",
lprofGetLoadModuleSignature(), ProfilePoolId);
if (S == -1 || S > SIGLEN)
S = SIGLEN;
memcpy(FilenameBuf + J, LoadModuleSignature, S);
J += S;
if (FilenamePat[I] != 'm')
I++;
}
/* Drop any unknown substitutions. */
} else
FilenameBuf[J++] = FilenamePat[I];
FilenameBuf[J] = 0;
return FilenameBuf;
}
/* Returns the pointer to the environment variable
* string. Returns null if the env var is not set. */
static const char *getFilenamePatFromEnv(void) {
const char *Filename = getenv("LLVM_PROFILE_FILE");
if (!Filename || !Filename[0])
return 0;
return Filename;
}
COMPILER_RT_VISIBILITY
const char *__llvm_profile_get_path_prefix(void) {
int Length;
char *FilenameBuf, *Prefix;
const char *Filename, *PrefixEnd;
if (lprofCurFilename.ProfilePathPrefix)
return lprofCurFilename.ProfilePathPrefix;
Length = getCurFilenameLength();
FilenameBuf = (char *)COMPILER_RT_ALLOCA(Length + 1);
Filename = getCurFilename(FilenameBuf, 0);
if (!Filename)
return "\0";
PrefixEnd = lprofFindLastDirSeparator(Filename);
if (!PrefixEnd)
return "\0";
Length = PrefixEnd - Filename + 1;
Prefix = (char *)malloc(Length + 1);
if (!Prefix) {
PROF_ERR("Failed to %s\n", "allocate memory.");
return "\0";
}
memcpy(Prefix, Filename, Length);
Prefix[Length] = '\0';
lprofCurFilename.ProfilePathPrefix = Prefix;
return Prefix;
}
COMPILER_RT_VISIBILITY
const char *__llvm_profile_get_filename(void) {
int Length;
char *FilenameBuf;
const char *Filename;
if (lprofCurFilename.Filename)
return lprofCurFilename.Filename;
Length = getCurFilenameLength();
FilenameBuf = (char *)malloc(Length + 1);
if (!FilenameBuf) {
PROF_ERR("Failed to %s\n", "allocate memory.");
return "\0";
}
Filename = getCurFilename(FilenameBuf, 1);
if (!Filename)
return "\0";
lprofCurFilename.Filename = FilenameBuf;
return FilenameBuf;
}
/* This method is invoked by the runtime initialization hook
* InstrProfilingRuntime.o if it is linked in. Both user specified
* profile path via -fprofile-instr-generate= and LLVM_PROFILE_FILE
* environment variable can override this default value. */
COMPILER_RT_VISIBILITY
void __llvm_profile_initialize_file(void) {
const char *EnvFilenamePat;
const char *SelectedPat = NULL;
ProfileNameSpecifier PNS = PNS_unknown;
int hasCommandLineOverrider = (INSTR_PROF_PROFILE_NAME_VAR[0] != 0);
EnvFilenamePat = getFilenamePatFromEnv();
if (EnvFilenamePat) {
/* Pass CopyFilenamePat = 1, to ensure that the filename would be valid
at the moment when __llvm_profile_write_file() gets executed. */
parseAndSetFilename(EnvFilenamePat, PNS_environment, 1);
return;
} else if (hasCommandLineOverrider) {
SelectedPat = INSTR_PROF_PROFILE_NAME_VAR;
PNS = PNS_command_line;
} else {
SelectedPat = NULL;
PNS = PNS_default;
}
parseAndSetFilename(SelectedPat, PNS, 0);
}
/* This API is directly called by the user application code. It has the
* highest precedence compared with LLVM_PROFILE_FILE environment variable
* and command line option -fprofile-instr-generate=<profile_name>.
*/
COMPILER_RT_VISIBILITY
void __llvm_profile_set_filename(const char *FilenamePat) {
parseAndSetFilename(FilenamePat, PNS_runtime_api, 1);
}
/* The public API for writing profile data into the file with name
* set by previous calls to __llvm_profile_set_filename or
* __llvm_profile_override_default_filename or
* __llvm_profile_initialize_file. */
COMPILER_RT_VISIBILITY
int __llvm_profile_write_file(void) {
int rc, Length;
const char *Filename;
char *FilenameBuf;
int PDeathSig = 0;
if (lprofProfileDumped()) {
PROF_NOTE("Profile data not written to file: %s.\n",
"already written");
return 0;
}
Length = getCurFilenameLength();
FilenameBuf = (char *)COMPILER_RT_ALLOCA(Length + 1);
Filename = getCurFilename(FilenameBuf, 0);
/* Check the filename. */
if (!Filename) {
PROF_ERR("Failed to write file : %s\n", "Filename not set");
return -1;
}
/* Check if there is llvm/runtime version mismatch. */
if (GET_VERSION(__llvm_profile_get_version()) != INSTR_PROF_RAW_VERSION) {
PROF_ERR("Runtime and instrumentation version mismatch : "
"expected %d, but get %d\n",
INSTR_PROF_RAW_VERSION,
(int)GET_VERSION(__llvm_profile_get_version()));
return -1;
}
// Temporarily suspend getting SIGKILL when the parent exits.
PDeathSig = lprofSuspendSigKill();
/* Write profile data to the file. */
rc = writeFile(Filename);
if (rc)
PROF_ERR("Failed to write file \"%s\": %s\n", Filename, strerror(errno));
// Restore SIGKILL.
if (PDeathSig == 1)
lprofRestoreSigKill();
return rc;
}
COMPILER_RT_VISIBILITY
int __llvm_profile_dump(void) {
if (!doMerging())
PROF_WARN("Later invocation of __llvm_profile_dump can lead to clobbering "
" of previously dumped profile data : %s. Either use %%m "
"in profile name or change profile name before dumping.\n",
"online profile merging is not on");
int rc = __llvm_profile_write_file();
lprofSetProfileDumped();
return rc;
}
static void writeFileWithoutReturn(void) { __llvm_profile_write_file(); }
COMPILER_RT_VISIBILITY
int __llvm_profile_register_write_file_atexit(void) {
static int HasBeenRegistered = 0;
if (HasBeenRegistered)
return 0;
lprofSetupValueProfiler();
HasBeenRegistered = 1;
return atexit(writeFileWithoutReturn);
}
#endif