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//===-- sanitizer_symbolizer_posix_libcdep.cpp ----------------------------===//
//
// 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
//
//===----------------------------------------------------------------------===//
//
// This file is shared between AddressSanitizer and ThreadSanitizer
// run-time libraries.
// POSIX-specific implementation of symbolizer parts.
//===----------------------------------------------------------------------===//
#include "sanitizer_platform.h"
#if SANITIZER_POSIX
#include "sanitizer_allocator_internal.h"
#include "sanitizer_common.h"
#include "sanitizer_file.h"
#include "sanitizer_flags.h"
#include "sanitizer_internal_defs.h"
#include "sanitizer_linux.h"
#include "sanitizer_placement_new.h"
#include "sanitizer_posix.h"
#include "sanitizer_procmaps.h"
#include "sanitizer_symbolizer_internal.h"
#include "sanitizer_symbolizer_libbacktrace.h"
#include "sanitizer_symbolizer_mac.h"
#include <dlfcn.h> // for dlsym()
#include <errno.h>
#include <stdint.h>
#include <stdlib.h>
#include <sys/wait.h>
#include <unistd.h>
#if SANITIZER_MAC
#include <util.h> // for forkpty()
#endif // SANITIZER_MAC
// C++ demangling function, as required by Itanium C++ ABI. This is weak,
// because we do not require a C++ ABI library to be linked to a program
// using sanitizers; if it's not present, we'll just use the mangled name.
namespace __cxxabiv1 {
extern "C" SANITIZER_WEAK_ATTRIBUTE
char *__cxa_demangle(const char *mangled, char *buffer,
size_t *length, int *status);
}
namespace __sanitizer {
// Attempts to demangle the name via __cxa_demangle from __cxxabiv1.
const char *DemangleCXXABI(const char *name) {
// FIXME: __cxa_demangle aggressively insists on allocating memory.
// There's not much we can do about that, short of providing our
// own demangler (libc++abi's implementation could be adapted so that
// it does not allocate). For now, we just call it anyway, and we leak
// the returned value.
if (&__cxxabiv1::__cxa_demangle)
if (const char *demangled_name =
__cxxabiv1::__cxa_demangle(name, 0, 0, 0))
return demangled_name;
return name;
}
// As of now, there are no headers for the Swift runtime. Once they are
// present, we will weakly link since we do not require Swift runtime to be
// linked.
typedef char *(*swift_demangle_ft)(const char *mangledName,
size_t mangledNameLength, char *outputBuffer,
size_t *outputBufferSize, uint32_t flags);
static swift_demangle_ft swift_demangle_f;
// This must not happen lazily at symbolication time, because dlsym uses
// malloc and thread-local storage, which is not a good thing to do during
// symbolication.
static void InitializeSwiftDemangler() {
swift_demangle_f = (swift_demangle_ft)dlsym(RTLD_DEFAULT, "swift_demangle");
(void)dlerror(); // Cleanup error message in case of failure
}
// Attempts to demangle a Swift name. The demangler will return nullptr if a
// non-Swift name is passed in.
const char *DemangleSwift(const char *name) {
if (!name) return nullptr;
// Check if we are dealing with a Swift mangled name first.
if (name[0] != '_' || name[1] != 'T') {
return nullptr;
}
if (swift_demangle_f)
return swift_demangle_f(name, internal_strlen(name), 0, 0, 0);
return nullptr;
}
const char *DemangleSwiftAndCXX(const char *name) {
if (!name) return nullptr;
if (const char *swift_demangled_name = DemangleSwift(name))
return swift_demangled_name;
return DemangleCXXABI(name);
}
static bool CreateTwoHighNumberedPipes(int *infd_, int *outfd_) {
int *infd = NULL;
int *outfd = NULL;
// The client program may close its stdin and/or stdout and/or stderr
// thus allowing socketpair to reuse file descriptors 0, 1 or 2.
// In this case the communication between the forked processes may be
// broken if either the parent or the child tries to close or duplicate
// these descriptors. The loop below produces two pairs of file
// descriptors, each greater than 2 (stderr).
int sock_pair[5][2];
for (int i = 0; i < 5; i++) {
if (pipe(sock_pair[i]) == -1) {
for (int j = 0; j < i; j++) {
internal_close(sock_pair[j][0]);
internal_close(sock_pair[j][1]);
}
return false;
} else if (sock_pair[i][0] > 2 && sock_pair[i][1] > 2) {
if (infd == NULL) {
infd = sock_pair[i];
} else {
outfd = sock_pair[i];
for (int j = 0; j < i; j++) {
if (sock_pair[j] == infd) continue;
internal_close(sock_pair[j][0]);
internal_close(sock_pair[j][1]);
}
break;
}
}
}
CHECK(infd);
CHECK(outfd);
infd_[0] = infd[0];
infd_[1] = infd[1];
outfd_[0] = outfd[0];
outfd_[1] = outfd[1];
return true;
}
bool SymbolizerProcess::StartSymbolizerSubprocess() {
if (!FileExists(path_)) {
if (!reported_invalid_path_) {
Report("WARNING: invalid path to external symbolizer!\n");
reported_invalid_path_ = true;
}
return false;
}
int pid = -1;
int infd[2];
internal_memset(&infd, 0, sizeof(infd));
int outfd[2];
internal_memset(&outfd, 0, sizeof(outfd));
if (!CreateTwoHighNumberedPipes(infd, outfd)) {
Report("WARNING: Can't create a socket pair to start "
"external symbolizer (errno: %d)\n", errno);
return false;
}
if (use_forkpty_) {
#if SANITIZER_MAC
fd_t fd = kInvalidFd;
// forkpty redirects stdout and stderr into a single stream, so we would
// receive error messages as standard replies. To avoid that, let's dup
// stderr and restore it in the child.
int saved_stderr = dup(STDERR_FILENO);
CHECK_GE(saved_stderr, 0);
// We only need one pipe, for stdin of the child.
close(outfd[0]);
close(outfd[1]);
// Use forkpty to disable buffering in the new terminal.
pid = internal_forkpty(&fd);
if (pid == -1) {
// forkpty() failed.
Report("WARNING: failed to fork external symbolizer (errno: %d)\n",
errno);
return false;
} else if (pid == 0) {
// Child subprocess.
// infd[0] is the child's reading end.
close(infd[1]);
// Set up stdin to read from the pipe.
CHECK_GE(dup2(infd[0], STDIN_FILENO), 0);
close(infd[0]);
// Restore stderr.
CHECK_GE(dup2(saved_stderr, STDERR_FILENO), 0);
close(saved_stderr);
const char *argv[kArgVMax];
GetArgV(path_, argv);
execv(path_, const_cast<char **>(&argv[0]));
internal__exit(1);
}
// Input for the child, infd[1] is our writing end.
output_fd_ = infd[1];
close(infd[0]);
// Continue execution in parent process.
input_fd_ = fd;
close(saved_stderr);
// Disable echo in the new terminal, disable CR.
struct termios termflags;
tcgetattr(fd, &termflags);
termflags.c_oflag &= ~ONLCR;
termflags.c_lflag &= ~ECHO;
tcsetattr(fd, TCSANOW, &termflags);
#else // SANITIZER_MAC
UNIMPLEMENTED();
#endif // SANITIZER_MAC
} else {
const char *argv[kArgVMax];
GetArgV(path_, argv);
pid = StartSubprocess(path_, argv, /* stdin */ outfd[0],
/* stdout */ infd[1]);
if (pid < 0) {
internal_close(infd[0]);
internal_close(outfd[1]);
return false;
}
input_fd_ = infd[0];
output_fd_ = outfd[1];
}
CHECK_GT(pid, 0);
// Check that symbolizer subprocess started successfully.
SleepForMillis(kSymbolizerStartupTimeMillis);
if (!IsProcessRunning(pid)) {
// Either waitpid failed, or child has already exited.
Report("WARNING: external symbolizer didn't start up correctly!\n");
return false;
}
return true;
}
class Addr2LineProcess : public SymbolizerProcess {
public:
Addr2LineProcess(const char *path, const char *module_name)
: SymbolizerProcess(path), module_name_(internal_strdup(module_name)) {}
const char *module_name() const { return module_name_; }
private:
void GetArgV(const char *path_to_binary,
const char *(&argv)[kArgVMax]) const override {
int i = 0;
argv[i++] = path_to_binary;
argv[i++] = "-iCfe";
argv[i++] = module_name_;
argv[i++] = nullptr;
}
bool ReachedEndOfOutput(const char *buffer, uptr length) const override;
bool ReadFromSymbolizer(char *buffer, uptr max_length) override {
if (!SymbolizerProcess::ReadFromSymbolizer(buffer, max_length))
return false;
// The returned buffer is empty when output is valid, but exceeds
// max_length.
if (*buffer == '\0')
return true;
// We should cut out output_terminator_ at the end of given buffer,
// appended by addr2line to mark the end of its meaningful output.
// We cannot scan buffer from it's beginning, because it is legal for it
// to start with output_terminator_ in case given offset is invalid. So,
// scanning from second character.
char *garbage = internal_strstr(buffer + 1, output_terminator_);
// This should never be NULL since buffer must end up with
// output_terminator_.
CHECK(garbage);
// Trim the buffer.
garbage[0] = '\0';
return true;
}
const char *module_name_; // Owned, leaked.
static const char output_terminator_[];
};
const char Addr2LineProcess::output_terminator_[] = "??\n??:0\n";
bool Addr2LineProcess::ReachedEndOfOutput(const char *buffer,
uptr length) const {
const size_t kTerminatorLen = sizeof(output_terminator_) - 1;
// Skip, if we read just kTerminatorLen bytes, because Addr2Line output
// should consist at least of two pairs of lines:
// 1. First one, corresponding to given offset to be symbolized
// (may be equal to output_terminator_, if offset is not valid).
// 2. Second one for output_terminator_, itself to mark the end of output.
if (length <= kTerminatorLen) return false;
// Addr2Line output should end up with output_terminator_.
return !internal_memcmp(buffer + length - kTerminatorLen,
output_terminator_, kTerminatorLen);
}
class Addr2LinePool : public SymbolizerTool {
public:
explicit Addr2LinePool(const char *addr2line_path,
LowLevelAllocator *allocator)
: addr2line_path_(addr2line_path), allocator_(allocator) {
addr2line_pool_.reserve(16);
}
bool SymbolizePC(uptr addr, SymbolizedStack *stack) override {
if (const char *buf =
SendCommand(stack->info.module, stack->info.module_offset)) {
ParseSymbolizePCOutput(buf, stack);
return true;
}
return false;
}
bool SymbolizeData(uptr addr, DataInfo *info) override {
return false;
}
private:
const char *SendCommand(const char *module_name, uptr module_offset) {
Addr2LineProcess *addr2line = 0;
for (uptr i = 0; i < addr2line_pool_.size(); ++i) {
if (0 ==
internal_strcmp(module_name, addr2line_pool_[i]->module_name())) {
addr2line = addr2line_pool_[i];
break;
}
}
if (!addr2line) {
addr2line =
new(*allocator_) Addr2LineProcess(addr2line_path_, module_name);
addr2line_pool_.push_back(addr2line);
}
CHECK_EQ(0, internal_strcmp(module_name, addr2line->module_name()));
char buffer[kBufferSize];
internal_snprintf(buffer, kBufferSize, "0x%zx\n0x%zx\n",
module_offset, dummy_address_);
return addr2line->SendCommand(buffer);
}
static const uptr kBufferSize = 64;
const char *addr2line_path_;
LowLevelAllocator *allocator_;
InternalMmapVector<Addr2LineProcess*> addr2line_pool_;
static const uptr dummy_address_ =
FIRST_32_SECOND_64(UINT32_MAX, UINT64_MAX);
};
#if SANITIZER_SUPPORTS_WEAK_HOOKS
extern "C" {
SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE
bool __sanitizer_symbolize_code(const char *ModuleName, u64 ModuleOffset,
char *Buffer, int MaxLength);
SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE
bool __sanitizer_symbolize_data(const char *ModuleName, u64 ModuleOffset,
char *Buffer, int MaxLength);
SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE
void __sanitizer_symbolize_flush();
SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE
int __sanitizer_symbolize_demangle(const char *Name, char *Buffer,
int MaxLength);
} // extern "C"
class InternalSymbolizer : public SymbolizerTool {
public:
static InternalSymbolizer *get(LowLevelAllocator *alloc) {
if (__sanitizer_symbolize_code != 0 &&
__sanitizer_symbolize_data != 0) {
return new(*alloc) InternalSymbolizer();
}
return 0;
}
bool SymbolizePC(uptr addr, SymbolizedStack *stack) override {
bool result = __sanitizer_symbolize_code(
stack->info.module, stack->info.module_offset, buffer_, kBufferSize);
if (result) ParseSymbolizePCOutput(buffer_, stack);
return result;
}
bool SymbolizeData(uptr addr, DataInfo *info) override {
bool result = __sanitizer_symbolize_data(info->module, info->module_offset,
buffer_, kBufferSize);
if (result) {
ParseSymbolizeDataOutput(buffer_, info);
info->start += (addr - info->module_offset); // Add the base address.
}
return result;
}
void Flush() override {
if (__sanitizer_symbolize_flush)
__sanitizer_symbolize_flush();
}
const char *Demangle(const char *name) override {
if (__sanitizer_symbolize_demangle) {
for (uptr res_length = 1024;
res_length <= InternalSizeClassMap::kMaxSize;) {
char *res_buff = static_cast<char*>(InternalAlloc(res_length));
uptr req_length =
__sanitizer_symbolize_demangle(name, res_buff, res_length);
if (req_length > res_length) {
res_length = req_length + 1;
InternalFree(res_buff);
continue;
}
return res_buff;
}
}
return name;
}
private:
InternalSymbolizer() { }
static const int kBufferSize = 16 * 1024;
char buffer_[kBufferSize];
};
#else // SANITIZER_SUPPORTS_WEAK_HOOKS
class InternalSymbolizer : public SymbolizerTool {
public:
static InternalSymbolizer *get(LowLevelAllocator *alloc) { return 0; }
};
#endif // SANITIZER_SUPPORTS_WEAK_HOOKS
const char *Symbolizer::PlatformDemangle(const char *name) {
return DemangleSwiftAndCXX(name);
}
static SymbolizerTool *ChooseExternalSymbolizer(LowLevelAllocator *allocator) {
const char *path = common_flags()->external_symbolizer_path;
const char *binary_name = path ? StripModuleName(path) : "";
if (path && path[0] == '\0') {
VReport(2, "External symbolizer is explicitly disabled.\n");
return nullptr;
} else if (!internal_strcmp(binary_name, "llvm-symbolizer")) {
VReport(2, "Using llvm-symbolizer at user-specified path: %s\n", path);
return new(*allocator) LLVMSymbolizer(path, allocator);
} else if (!internal_strcmp(binary_name, "atos")) {
#if SANITIZER_MAC
VReport(2, "Using atos at user-specified path: %s\n", path);
return new(*allocator) AtosSymbolizer(path, allocator);
#else // SANITIZER_MAC
Report("ERROR: Using `atos` is only supported on Darwin.\n");
Die();
#endif // SANITIZER_MAC
} else if (!internal_strcmp(binary_name, "addr2line")) {
VReport(2, "Using addr2line at user-specified path: %s\n", path);
return new(*allocator) Addr2LinePool(path, allocator);
} else if (path) {
Report("ERROR: External symbolizer path is set to '%s' which isn't "
"a known symbolizer. Please set the path to the llvm-symbolizer "
"binary or other known tool.\n", path);
Die();
}
// Otherwise symbolizer program is unknown, let's search $PATH
CHECK(path == nullptr);
#if SANITIZER_MAC
if (const char *found_path = FindPathToBinary("atos")) {
VReport(2, "Using atos found at: %s\n", found_path);
return new(*allocator) AtosSymbolizer(found_path, allocator);
}
#endif // SANITIZER_MAC
if (const char *found_path = FindPathToBinary("llvm-symbolizer")) {
VReport(2, "Using llvm-symbolizer found at: %s\n", found_path);
return new(*allocator) LLVMSymbolizer(found_path, allocator);
}
if (common_flags()->allow_addr2line) {
if (const char *found_path = FindPathToBinary("addr2line")) {
VReport(2, "Using addr2line found at: %s\n", found_path);
return new(*allocator) Addr2LinePool(found_path, allocator);
}
}
return nullptr;
}
static void ChooseSymbolizerTools(IntrusiveList<SymbolizerTool> *list,
LowLevelAllocator *allocator) {
if (!common_flags()->symbolize) {
VReport(2, "Symbolizer is disabled.\n");
return;
}
if (IsAllocatorOutOfMemory()) {
VReport(2, "Cannot use internal symbolizer: out of memory\n");
} else if (SymbolizerTool *tool = InternalSymbolizer::get(allocator)) {
VReport(2, "Using internal symbolizer.\n");
list->push_back(tool);
return;
}
if (SymbolizerTool *tool = LibbacktraceSymbolizer::get(allocator)) {
VReport(2, "Using libbacktrace symbolizer.\n");
list->push_back(tool);
return;
}
if (SymbolizerTool *tool = ChooseExternalSymbolizer(allocator)) {
list->push_back(tool);
}
#if SANITIZER_MAC
VReport(2, "Using dladdr symbolizer.\n");
list->push_back(new(*allocator) DlAddrSymbolizer());
#endif // SANITIZER_MAC
}
Symbolizer *Symbolizer::PlatformInit() {
IntrusiveList<SymbolizerTool> list;
list.clear();
ChooseSymbolizerTools(&list, &symbolizer_allocator_);
return new(symbolizer_allocator_) Symbolizer(list);
}
void Symbolizer::LateInitialize() {
Symbolizer::GetOrInit();
InitializeSwiftDemangler();
}
} // namespace __sanitizer
#endif // SANITIZER_POSIX
|