llvm-project/compiler-rt/lib/profile/InstrProfilingUtil.c

376 lines
9.2 KiB
C

/*===- InstrProfilingUtil.c - Support library for PGO instrumentation -----===*\
|*
|* Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
|* See https://llvm.org/LICENSE.txt for license information.
|* SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
|*
\*===----------------------------------------------------------------------===*/
#ifdef _WIN32
#include <direct.h>
#include <process.h>
#include <windows.h>
#include "WindowsMMap.h"
#else
#include <errno.h>
#include <fcntl.h>
#include <sys/file.h>
#include <sys/mman.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <unistd.h>
#endif
#ifdef COMPILER_RT_HAS_UNAME
#include <sys/utsname.h>
#endif
#include <stdlib.h>
#include <string.h>
#if defined(__linux__)
#include <signal.h>
#include <sys/prctl.h>
#endif
#if defined(__Fuchsia__)
#include <zircon/process.h>
#include <zircon/syscalls.h>
#endif
#if defined(__FreeBSD__)
#include <signal.h>
#include <sys/procctl.h>
#endif
#include "InstrProfiling.h"
#include "InstrProfilingUtil.h"
COMPILER_RT_WEAK unsigned lprofDirMode = 0755;
COMPILER_RT_VISIBILITY
void __llvm_profile_recursive_mkdir(char *path) {
int i;
int start = 1;
#if defined(__ANDROID__) && defined(__ANDROID_API__) && \
defined(__ANDROID_API_FUTURE__) && \
__ANDROID_API__ == __ANDROID_API_FUTURE__
// Avoid spammy selinux denial messages in Android by not attempting to
// create directories in GCOV_PREFIX. These denials occur when creating (or
// even attempting to stat()) top-level directories like "/data".
//
// Do so by ignoring ${GCOV_PREFIX} when invoking mkdir().
const char *gcov_prefix = getenv("GCOV_PREFIX");
if (gcov_prefix != NULL) {
const int gcov_prefix_len = strlen(gcov_prefix);
if (strncmp(path, gcov_prefix, gcov_prefix_len) == 0)
start = gcov_prefix_len;
}
#endif
for (i = start; path[i] != '\0'; ++i) {
char save = path[i];
if (!IS_DIR_SEPARATOR(path[i]))
continue;
path[i] = '\0';
#ifdef _WIN32
_mkdir(path);
#else
/* Some of these will fail, ignore it. */
mkdir(path, __llvm_profile_get_dir_mode());
#endif
path[i] = save;
}
}
COMPILER_RT_VISIBILITY
void __llvm_profile_set_dir_mode(unsigned Mode) { lprofDirMode = Mode; }
COMPILER_RT_VISIBILITY
unsigned __llvm_profile_get_dir_mode(void) { return lprofDirMode; }
#if COMPILER_RT_HAS_ATOMICS != 1
COMPILER_RT_VISIBILITY
uint32_t lprofBoolCmpXchg(void **Ptr, void *OldV, void *NewV) {
void *R = *Ptr;
if (R == OldV) {
*Ptr = NewV;
return 1;
}
return 0;
}
COMPILER_RT_VISIBILITY
void *lprofPtrFetchAdd(void **Mem, long ByteIncr) {
void *Old = *Mem;
*((char **)Mem) += ByteIncr;
return Old;
}
#endif
#ifdef _WIN32
COMPILER_RT_VISIBILITY int lprofGetHostName(char *Name, int Len) {
WCHAR Buffer[COMPILER_RT_MAX_HOSTLEN];
DWORD BufferSize = sizeof(Buffer);
BOOL Result =
GetComputerNameExW(ComputerNameDnsFullyQualified, Buffer, &BufferSize);
if (!Result)
return -1;
if (WideCharToMultiByte(CP_UTF8, 0, Buffer, -1, Name, Len, NULL, NULL) == 0)
return -1;
return 0;
}
#elif defined(COMPILER_RT_HAS_UNAME)
COMPILER_RT_VISIBILITY int lprofGetHostName(char *Name, int Len) {
struct utsname N;
int R = uname(&N);
if (R >= 0) {
strncpy(Name, N.nodename, Len);
return 0;
}
return R;
}
#endif
COMPILER_RT_VISIBILITY int lprofLockFd(int fd) {
#ifdef COMPILER_RT_HAS_FCNTL_LCK
struct flock s_flock;
s_flock.l_whence = SEEK_SET;
s_flock.l_start = 0;
s_flock.l_len = 0; /* Until EOF. */
s_flock.l_pid = getpid();
s_flock.l_type = F_WRLCK;
while (fcntl(fd, F_SETLKW, &s_flock) == -1) {
if (errno != EINTR) {
if (errno == ENOLCK) {
return -1;
}
break;
}
}
return 0;
#else
flock(fd, LOCK_EX);
return 0;
#endif
}
COMPILER_RT_VISIBILITY int lprofUnlockFd(int fd) {
#ifdef COMPILER_RT_HAS_FCNTL_LCK
struct flock s_flock;
s_flock.l_whence = SEEK_SET;
s_flock.l_start = 0;
s_flock.l_len = 0; /* Until EOF. */
s_flock.l_pid = getpid();
s_flock.l_type = F_UNLCK;
while (fcntl(fd, F_SETLKW, &s_flock) == -1) {
if (errno != EINTR) {
if (errno == ENOLCK) {
return -1;
}
break;
}
}
return 0;
#else
flock(fd, LOCK_UN);
return 0;
#endif
}
COMPILER_RT_VISIBILITY int lprofLockFileHandle(FILE *F) {
int fd;
#if defined(_WIN32)
fd = _fileno(F);
#else
fd = fileno(F);
#endif
return lprofLockFd(fd);
}
COMPILER_RT_VISIBILITY int lprofUnlockFileHandle(FILE *F) {
int fd;
#if defined(_WIN32)
fd = _fileno(F);
#else
fd = fileno(F);
#endif
return lprofUnlockFd(fd);
}
COMPILER_RT_VISIBILITY FILE *lprofOpenFileEx(const char *ProfileName) {
FILE *f;
int fd;
#ifdef COMPILER_RT_HAS_FCNTL_LCK
fd = open(ProfileName, O_RDWR | O_CREAT, 0666);
if (fd < 0)
return NULL;
if (lprofLockFd(fd) != 0)
PROF_WARN("Data may be corrupted during profile merging : %s\n",
"Fail to obtain file lock due to system limit.");
f = fdopen(fd, "r+b");
#elif defined(_WIN32)
// FIXME: Use the wide variants to handle Unicode filenames.
HANDLE h = CreateFileA(ProfileName, GENERIC_READ | GENERIC_WRITE,
FILE_SHARE_READ | FILE_SHARE_WRITE, 0, OPEN_ALWAYS,
FILE_ATTRIBUTE_NORMAL, 0);
if (h == INVALID_HANDLE_VALUE)
return NULL;
fd = _open_osfhandle((intptr_t)h, 0);
if (fd == -1) {
CloseHandle(h);
return NULL;
}
if (lprofLockFd(fd) != 0)
PROF_WARN("Data may be corrupted during profile merging : %s\n",
"Fail to obtain file lock due to system limit.");
f = _fdopen(fd, "r+b");
if (f == 0) {
CloseHandle(h);
return NULL;
}
#else
/* Worst case no locking applied. */
PROF_WARN("Concurrent file access is not supported : %s\n",
"lack file locking");
fd = open(ProfileName, O_RDWR | O_CREAT, 0666);
if (fd < 0)
return NULL;
f = fdopen(fd, "r+b");
#endif
return f;
}
COMPILER_RT_VISIBILITY const char *lprofGetPathPrefix(int *PrefixStrip,
size_t *PrefixLen) {
const char *Prefix = getenv("GCOV_PREFIX");
const char *PrefixStripStr = getenv("GCOV_PREFIX_STRIP");
*PrefixLen = 0;
*PrefixStrip = 0;
if (Prefix == NULL || Prefix[0] == '\0')
return NULL;
if (PrefixStripStr) {
*PrefixStrip = atoi(PrefixStripStr);
/* Negative GCOV_PREFIX_STRIP values are ignored */
if (*PrefixStrip < 0)
*PrefixStrip = 0;
} else {
*PrefixStrip = 0;
}
*PrefixLen = strlen(Prefix);
return Prefix;
}
COMPILER_RT_VISIBILITY void
lprofApplyPathPrefix(char *Dest, const char *PathStr, const char *Prefix,
size_t PrefixLen, int PrefixStrip) {
const char *Ptr;
int Level;
const char *StrippedPathStr = PathStr;
for (Level = 0, Ptr = PathStr + 1; Level < PrefixStrip; ++Ptr) {
if (*Ptr == '\0')
break;
if (!IS_DIR_SEPARATOR(*Ptr))
continue;
StrippedPathStr = Ptr;
++Level;
}
memcpy(Dest, Prefix, PrefixLen);
if (!IS_DIR_SEPARATOR(Prefix[PrefixLen - 1]))
Dest[PrefixLen++] = DIR_SEPARATOR;
memcpy(Dest + PrefixLen, StrippedPathStr, strlen(StrippedPathStr) + 1);
}
COMPILER_RT_VISIBILITY const char *
lprofFindFirstDirSeparator(const char *Path) {
const char *Sep = strchr(Path, DIR_SEPARATOR);
#if defined(DIR_SEPARATOR_2)
const char *Sep2 = strchr(Path, DIR_SEPARATOR_2);
if (Sep2 && (!Sep || Sep2 < Sep))
Sep = Sep2;
#endif
return Sep;
}
COMPILER_RT_VISIBILITY const char *lprofFindLastDirSeparator(const char *Path) {
const char *Sep = strrchr(Path, DIR_SEPARATOR);
#if defined(DIR_SEPARATOR_2)
const char *Sep2 = strrchr(Path, DIR_SEPARATOR_2);
if (Sep2 && (!Sep || Sep2 > Sep))
Sep = Sep2;
#endif
return Sep;
}
COMPILER_RT_VISIBILITY int lprofSuspendSigKill() {
#if defined(__linux__)
int PDeachSig = 0;
/* Temporarily suspend getting SIGKILL upon exit of the parent process. */
if (prctl(PR_GET_PDEATHSIG, &PDeachSig) == 0 && PDeachSig == SIGKILL)
prctl(PR_SET_PDEATHSIG, 0);
return (PDeachSig == SIGKILL);
#elif defined(__FreeBSD__)
int PDeachSig = 0, PDisableSig = 0;
if (procctl(P_PID, 0, PROC_PDEATHSIG_STATUS, &PDeachSig) == 0 &&
PDeachSig == SIGKILL)
procctl(P_PID, 0, PROC_PDEATHSIG_CTL, &PDisableSig);
return (PDeachSig == SIGKILL);
#else
return 0;
#endif
}
COMPILER_RT_VISIBILITY void lprofRestoreSigKill() {
#if defined(__linux__)
prctl(PR_SET_PDEATHSIG, SIGKILL);
#elif defined(__FreeBSD__)
int PEnableSig = SIGKILL;
procctl(P_PID, 0, PROC_PDEATHSIG_CTL, &PEnableSig);
#endif
}
COMPILER_RT_VISIBILITY int lprofReleaseMemoryPagesToOS(uintptr_t Begin,
uintptr_t End) {
#if defined(__ve__)
// VE doesn't support madvise.
return 0;
#else
size_t PageSize = getpagesize();
uintptr_t BeginAligned = lprofRoundUpTo((uintptr_t)Begin, PageSize);
uintptr_t EndAligned = lprofRoundDownTo((uintptr_t)End, PageSize);
if (BeginAligned < EndAligned) {
#if defined(__Fuchsia__)
return _zx_vmar_op_range(_zx_vmar_root_self(), ZX_VMAR_OP_DECOMMIT,
(zx_vaddr_t)BeginAligned,
EndAligned - BeginAligned, NULL, 0);
#else
return madvise((void *)BeginAligned, EndAligned - BeginAligned,
MADV_DONTNEED);
#endif
}
return 0;
#endif
}