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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
#include "SharedLibraries.h"
#define PATH_MAX_TOSTRING(x) #x
#define PATH_MAX_STRING(x) PATH_MAX_TOSTRING(x)
#include <stdio.h>
#include <string.h>
#include <limits.h>
#include <unistd.h>
#include <fstream>
#include "platform.h"
#include "mozilla/Sprintf.h"
#include <algorithm>
#include <arpa/inet.h>
#include <elf.h>
#include <fcntl.h>
#if defined(GP_OS_linux) || defined(GP_OS_android)
# include <features.h>
#endif
#include <sys/mman.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <vector>
#include <optional>
#if defined(GP_OS_linux) || defined(GP_OS_android) || defined(GP_OS_freebsd)
# include <link.h> // dl_phdr_info, ElfW()
#else
# error "Unexpected configuration"
#endif
#if defined(GP_OS_android)
extern "C" MOZ_EXPORT __attribute__((weak)) int dl_iterate_phdr(
int (*callback)(struct dl_phdr_info* info, size_t size, void* data),
void* data);
#endif
#if defined(GP_OS_freebsd) && !defined(ElfW)
# define ElfW(type) Elf_##type
#endif
// ----------------------------------------------------------------------------
// Starting imports from toolkit/crashreporter/google-breakpad/, as needed by
// this file when moved to mozglue.
// Imported from
// toolkit/crashreporter/google-breakpad/src/common/memory_range.h.
// A lightweight wrapper with a pointer and a length to encapsulate a contiguous
// range of memory. It provides helper methods for checked access of a subrange
// of the memory. Its implemementation does not allocate memory or call into
// libc functions, and is thus safer to use in a crashed environment.
class MemoryRange {
public:
MemoryRange() : data_(NULL), length_(0) {}
MemoryRange(const void* data, size_t length) { Set(data, length); }
// Returns true if this memory range contains no data.
bool IsEmpty() const {
// Set() guarantees that |length_| is zero if |data_| is NULL.
return length_ == 0;
}
// Resets to an empty range.
void Reset() {
data_ = NULL;
length_ = 0;
}
// Sets this memory range to point to |data| and its length to |length|.
void Set(const void* data, size_t length) {
data_ = reinterpret_cast<const uint8_t*>(data);
// Always set |length_| to zero if |data_| is NULL.
length_ = data ? length : 0;
}
// Returns true if this range covers a subrange of |sub_length| bytes
// at |sub_offset| bytes of this memory range, or false otherwise.
bool Covers(size_t sub_offset, size_t sub_length) const {
// The following checks verify that:
// 1. sub_offset is within [ 0 .. length_ - 1 ]
// 2. sub_offset + sub_length is within
// [ sub_offset .. length_ ]
return sub_offset < length_ && sub_offset + sub_length >= sub_offset &&
sub_offset + sub_length <= length_;
}
// Returns a raw data pointer to a subrange of |sub_length| bytes at
// |sub_offset| bytes of this memory range, or NULL if the subrange
// is out of bounds.
const void* GetData(size_t sub_offset, size_t sub_length) const {
return Covers(sub_offset, sub_length) ? (data_ + sub_offset) : NULL;
}
// Same as the two-argument version of GetData() but uses sizeof(DataType)
// as the subrange length and returns an |DataType| pointer for convenience.
template <typename DataType>
const DataType* GetData(size_t sub_offset) const {
return reinterpret_cast<const DataType*>(
GetData(sub_offset, sizeof(DataType)));
}
// Returns a raw pointer to the |element_index|-th element of an array
// of elements of length |element_size| starting at |sub_offset| bytes
// of this memory range, or NULL if the element is out of bounds.
const void* GetArrayElement(size_t element_offset, size_t element_size,
unsigned element_index) const {
size_t sub_offset = element_offset + element_index * element_size;
return GetData(sub_offset, element_size);
}
// Same as the three-argument version of GetArrayElement() but deduces
// the element size using sizeof(ElementType) and returns an |ElementType|
// pointer for convenience.
template <typename ElementType>
const ElementType* GetArrayElement(size_t element_offset,
unsigned element_index) const {
return reinterpret_cast<const ElementType*>(
GetArrayElement(element_offset, sizeof(ElementType), element_index));
}
// Returns a subrange of |sub_length| bytes at |sub_offset| bytes of
// this memory range, or an empty range if the subrange is out of bounds.
MemoryRange Subrange(size_t sub_offset, size_t sub_length) const {
return Covers(sub_offset, sub_length)
? MemoryRange(data_ + sub_offset, sub_length)
: MemoryRange();
}
// Returns a pointer to the beginning of this memory range.
const uint8_t* data() const { return data_; }
// Returns the length, in bytes, of this memory range.
size_t length() const { return length_; }
private:
// Pointer to the beginning of this memory range.
const uint8_t* data_;
// Length, in bytes, of this memory range.
size_t length_;
};
// Imported from
// toolkit/crashreporter/google-breakpad/src/common/linux/memory_mapped_file.h
// and inlined .cc.
// A utility class for mapping a file into memory for read-only access of the
// file content. Its implementation avoids calling into libc functions by
// directly making system calls for open, close, mmap, and munmap.
class MemoryMappedFile {
public:
MemoryMappedFile() {}
// Constructor that calls Map() to map a file at |path| into memory.
// If Map() fails, the object behaves as if it is default constructed.
MemoryMappedFile(const char* path, size_t offset) { Map(path, offset); }
MemoryMappedFile(const MemoryMappedFile&) = delete;
MemoryMappedFile& operator=(const MemoryMappedFile&) = delete;
~MemoryMappedFile() { Unmap(); }
// Maps a file at |path| into memory, which can then be accessed via
// content() as a MemoryRange object or via data(), and returns true on
// success. Mapping an empty file will succeed but with data() and size()
// returning NULL and 0, respectively. An existing mapping is unmapped
// before a new mapping is created.
bool Map(const char* path, size_t offset) {
Unmap();
int fd = open(path, O_RDONLY, 0);
if (fd == -1) {
return false;
}
#if defined(__x86_64__) || defined(__aarch64__) || \
(defined(__mips__) && _MIPS_SIM == _ABI64) || \
!(defined(GP_OS_linux) || defined(GP_OS_android))
struct stat st;
if (fstat(fd, &st) == -1 || st.st_size < 0) {
#else
struct stat64 st;
if (fstat64(fd, &st) == -1 || st.st_size < 0) {
#endif
close(fd);
return false;
}
// Strangely file size can be negative, but we check above that it is not.
size_t file_len = static_cast<size_t>(st.st_size);
// If the file does not extend beyond the offset, simply use an empty
// MemoryRange and return true. Don't bother to call mmap()
// even though mmap() can handle an empty file on some platforms.
if (offset >= file_len) {
close(fd);
return true;
}
void* data = mmap(NULL, file_len, PROT_READ, MAP_PRIVATE, fd, offset);
close(fd);
if (data == MAP_FAILED) {
return false;
}
content_.Set(data, file_len - offset);
return true;
}
// Unmaps the memory for the mapped file. It's a no-op if no file is
// mapped.
void Unmap() {
if (content_.data()) {
munmap(const_cast<uint8_t*>(content_.data()), content_.length());
content_.Set(NULL, 0);
}
}
// Returns a MemoryRange object that covers the memory for the mapped
// file. The MemoryRange object is empty if no file is mapped.
const MemoryRange& content() const { return content_; }
// Returns a pointer to the beginning of the memory for the mapped file.
// or NULL if no file is mapped or the mapped file is empty.
const void* data() const { return content_.data(); }
// Returns the size in bytes of the mapped file, or zero if no file
// is mapped.
size_t size() const { return content_.length(); }
private:
// Mapped file content as a MemoryRange object.
MemoryRange content_;
};
// Imported from
// toolkit/crashreporter/google-breakpad/src/common/linux/file_id.h and inlined
// .cc.
// GNU binutils' ld defaults to 'sha1', which is 160 bits == 20 bytes,
// so this is enough to fit that, which most binaries will use.
// This is just a sensible default for vectors so most callers can get away with
// stack allocation.
static const size_t kDefaultBuildIdSize = 20;
// Used in a few places for backwards-compatibility.
typedef struct {
uint32_t data1;
uint16_t data2;
uint16_t data3;
uint8_t data4[8];
} MDGUID; /* GUID */
const size_t kMDGUIDSize = sizeof(MDGUID);
class FileID {
public:
explicit FileID(const char* path) : path_(path) {}
~FileID() {}
// Load the identifier for the elf file path specified in the constructor into
// |identifier|.
//
// The current implementation will look for a .note.gnu.build-id
// section and use that as the file id, otherwise it falls back to
// XORing the first 4096 bytes of the .text section to generate an identifier.
bool ElfFileIdentifier(std::vector<uint8_t>& identifier) {
MemoryMappedFile mapped_file(path_.c_str(), 0);
if (!mapped_file.data()) // Should probably check if size >= ElfW(Ehdr)?
return false;
return ElfFileIdentifierFromMappedFile(mapped_file.data(), identifier);
}
// Traits classes so consumers can write templatized code to deal
// with specific ELF bits.
struct ElfClass32 {
typedef Elf32_Addr Addr;
typedef Elf32_Ehdr Ehdr;
typedef Elf32_Nhdr Nhdr;
typedef Elf32_Phdr Phdr;
typedef Elf32_Shdr Shdr;
typedef Elf32_Half Half;
typedef Elf32_Off Off;
typedef Elf32_Sym Sym;
typedef Elf32_Word Word;
static const int kClass = ELFCLASS32;
static const uint16_t kMachine = EM_386;
static const size_t kAddrSize = sizeof(Elf32_Addr);
static constexpr const char* kMachineName = "x86";
};
struct ElfClass64 {
typedef Elf64_Addr Addr;
typedef Elf64_Ehdr Ehdr;
typedef Elf64_Nhdr Nhdr;
typedef Elf64_Phdr Phdr;
typedef Elf64_Shdr Shdr;
typedef Elf64_Half Half;
typedef Elf64_Off Off;
typedef Elf64_Sym Sym;
typedef Elf64_Word Word;
static const int kClass = ELFCLASS64;
static const uint16_t kMachine = EM_X86_64;
static const size_t kAddrSize = sizeof(Elf64_Addr);
static constexpr const char* kMachineName = "x86_64";
};
// Internal helper method, exposed for convenience for callers
// that already have more info.
template <typename ElfClass>
static const typename ElfClass::Shdr* FindElfSectionByName(
const char* name, typename ElfClass::Word section_type,
const typename ElfClass::Shdr* sections, const char* section_names,
const char* names_end, int nsection) {
if (!name || !sections || nsection == 0) {
return NULL;
}
int name_len = strlen(name);
if (name_len == 0) return NULL;
for (int i = 0; i < nsection; ++i) {
const char* section_name = section_names + sections[i].sh_name;
if (sections[i].sh_type == section_type &&
names_end - section_name >= name_len + 1 &&
strcmp(name, section_name) == 0) {
return sections + i;
}
}
return NULL;
}
struct ElfSegment {
const void* start;
size_t size;
};
// Convert an offset from an Elf header into a pointer to the mapped
// address in the current process. Takes an extra template parameter
// to specify the return type to avoid having to dynamic_cast the
// result.
template <typename ElfClass, typename T>
static const T* GetOffset(const typename ElfClass::Ehdr* elf_header,
typename ElfClass::Off offset) {
return reinterpret_cast<const T*>(reinterpret_cast<uintptr_t>(elf_header) +
offset);
}
// ELF note name and desc are 32-bits word padded.
#define NOTE_PADDING(a) ((a + 3) & ~3)
static bool ElfClassBuildIDNoteIdentifier(const void* section, size_t length,
std::vector<uint8_t>& identifier) {
static_assert(sizeof(ElfClass32::Nhdr) == sizeof(ElfClass64::Nhdr),
"Elf32_Nhdr and Elf64_Nhdr should be the same");
typedef typename ElfClass32::Nhdr Nhdr;
const void* section_end = reinterpret_cast<const char*>(section) + length;
const Nhdr* note_header = reinterpret_cast<const Nhdr*>(section);
while (reinterpret_cast<const void*>(note_header) < section_end) {
if (note_header->n_type == NT_GNU_BUILD_ID) break;
note_header = reinterpret_cast<const Nhdr*>(
reinterpret_cast<const char*>(note_header) + sizeof(Nhdr) +
NOTE_PADDING(note_header->n_namesz) +
NOTE_PADDING(note_header->n_descsz));
}
if (reinterpret_cast<const void*>(note_header) >= section_end ||
note_header->n_descsz == 0) {
return false;
}
const uint8_t* build_id = reinterpret_cast<const uint8_t*>(note_header) +
sizeof(Nhdr) +
NOTE_PADDING(note_header->n_namesz);
identifier.insert(identifier.end(), build_id,
build_id + note_header->n_descsz);
return true;
}
template <typename ElfClass>
static bool FindElfClassSection(const char* elf_base,
const char* section_name,
typename ElfClass::Word section_type,
const void** section_start,
size_t* section_size) {
typedef typename ElfClass::Ehdr Ehdr;
typedef typename ElfClass::Shdr Shdr;
if (!elf_base || !section_start || !section_size) {
return false;
}
if (strncmp(elf_base, ELFMAG, SELFMAG) != 0) {
return false;
}
const Ehdr* elf_header = reinterpret_cast<const Ehdr*>(elf_base);
if (elf_header->e_ident[EI_CLASS] != ElfClass::kClass) {
return false;
}
const Shdr* sections =
GetOffset<ElfClass, Shdr>(elf_header, elf_header->e_shoff);
const Shdr* section_names = sections + elf_header->e_shstrndx;
const char* names =
GetOffset<ElfClass, char>(elf_header, section_names->sh_offset);
const char* names_end = names + section_names->sh_size;
const Shdr* section =
FindElfSectionByName<ElfClass>(section_name, section_type, sections,
names, names_end, elf_header->e_shnum);
if (section != NULL && section->sh_size > 0) {
*section_start = elf_base + section->sh_offset;
*section_size = section->sh_size;
}
return true;
}
template <typename ElfClass>
static bool FindElfClassSegment(const char* elf_base,
typename ElfClass::Word segment_type,
std::vector<ElfSegment>* segments) {
typedef typename ElfClass::Ehdr Ehdr;
typedef typename ElfClass::Phdr Phdr;
if (!elf_base || !segments) {
return false;
}
if (strncmp(elf_base, ELFMAG, SELFMAG) != 0) {
return false;
}
const Ehdr* elf_header = reinterpret_cast<const Ehdr*>(elf_base);
if (elf_header->e_ident[EI_CLASS] != ElfClass::kClass) {
return false;
}
const Phdr* phdrs =
GetOffset<ElfClass, Phdr>(elf_header, elf_header->e_phoff);
for (int i = 0; i < elf_header->e_phnum; ++i) {
if (phdrs[i].p_type == segment_type) {
ElfSegment seg = {};
seg.start = elf_base + phdrs[i].p_offset;
seg.size = phdrs[i].p_filesz;
segments->push_back(seg);
}
}
return true;
}
static bool IsValidElf(const void* elf_base) {
return strncmp(reinterpret_cast<const char*>(elf_base), ELFMAG, SELFMAG) ==
0;
}
static int ElfClass(const void* elf_base) {
const ElfW(Ehdr)* elf_header =
reinterpret_cast<const ElfW(Ehdr)*>(elf_base);
return elf_header->e_ident[EI_CLASS];
}
static bool FindElfSection(const void* elf_mapped_base,
const char* section_name, uint32_t section_type,
const void** section_start, size_t* section_size) {
if (!elf_mapped_base || !section_start || !section_size) {
return false;
}
*section_start = NULL;
*section_size = 0;
if (!IsValidElf(elf_mapped_base)) return false;
int cls = ElfClass(elf_mapped_base);
const char* elf_base = static_cast<const char*>(elf_mapped_base);
if (cls == ELFCLASS32) {
return FindElfClassSection<ElfClass32>(elf_base, section_name,
section_type, section_start,
section_size) &&
*section_start != NULL;
} else if (cls == ELFCLASS64) {
return FindElfClassSection<ElfClass64>(elf_base, section_name,
section_type, section_start,
section_size) &&
*section_start != NULL;
}
return false;
}
static bool FindElfSegments(const void* elf_mapped_base,
uint32_t segment_type,
std::vector<ElfSegment>* segments) {
if (!elf_mapped_base || !segments) {
return false;
}
if (!IsValidElf(elf_mapped_base)) return false;
int cls = ElfClass(elf_mapped_base);
const char* elf_base = static_cast<const char*>(elf_mapped_base);
if (cls == ELFCLASS32) {
return FindElfClassSegment<ElfClass32>(elf_base, segment_type, segments);
}
if (cls == ELFCLASS64) {
return FindElfClassSegment<ElfClass64>(elf_base, segment_type, segments);
}
return false;
}
// Attempt to locate a .note.gnu.build-id section in an ELF binary
// and copy it into |identifier|.
static bool FindElfBuildIDNote(const void* elf_mapped_base,
std::vector<uint8_t>& identifier) {
// lld normally creates 2 PT_NOTEs, gold normally creates 1.
std::vector<ElfSegment> segs;
if (FindElfSegments(elf_mapped_base, PT_NOTE, &segs)) {
for (ElfSegment& seg : segs) {
if (ElfClassBuildIDNoteIdentifier(seg.start, seg.size, identifier)) {
return true;
}
}
}
void* note_section;
size_t note_size;
if (FindElfSection(elf_mapped_base, ".note.gnu.build-id", SHT_NOTE,
(const void**)¬e_section, ¬e_size)) {
return ElfClassBuildIDNoteIdentifier(note_section, note_size, identifier);
}
return false;
}
// Attempt to locate the .text section of an ELF binary and generate
// a simple hash by XORing the first page worth of bytes into |identifier|.
static bool HashElfTextSection(const void* elf_mapped_base,
std::vector<uint8_t>& identifier) {
void* text_section;
size_t text_size;
if (!FindElfSection(elf_mapped_base, ".text", SHT_PROGBITS,
(const void**)&text_section, &text_size) ||
text_size == 0) {
return false;
}
// Only provide |kMDGUIDSize| bytes to keep identifiers produced by this
// function backwards-compatible.
identifier.resize(kMDGUIDSize);
memset(&identifier[0], 0, kMDGUIDSize);
const uint8_t* ptr = reinterpret_cast<const uint8_t*>(text_section);
const uint8_t* ptr_end =
ptr + std::min(text_size, static_cast<size_t>(4096));
while (ptr < ptr_end) {
for (unsigned i = 0; i < kMDGUIDSize; i++) identifier[i] ^= ptr[i];
ptr += kMDGUIDSize;
}
return true;
}
// Load the identifier for the elf file mapped into memory at |base| into
// |identifier|. Return false if the identifier could not be created for this
// file.
static bool ElfFileIdentifierFromMappedFile(
const void* base, std::vector<uint8_t>& identifier) {
// Look for a build id note first.
if (FindElfBuildIDNote(base, identifier)) return true;
// Fall back on hashing the first page of the text section.
return HashElfTextSection(base, identifier);
}
// These three functions are not ever called in an unsafe context, so it's OK
// to allocate memory and use libc.
static std::string bytes_to_hex_string(const uint8_t* bytes, size_t count,
bool lowercase = false) {
std::string result;
for (unsigned int idx = 0; idx < count; ++idx) {
char buf[3];
SprintfLiteral(buf, lowercase ? "%02x" : "%02X", bytes[idx]);
result.append(buf);
}
return result;
}
// Convert the |identifier| data to a string. The string will
// be formatted as a UUID in all uppercase without dashes.
// (e.g., 22F065BBFC9C49F780FE26A7CEBD7BCE).
static std::string ConvertIdentifierToUUIDString(
const std::vector<uint8_t>& identifier) {
uint8_t identifier_swapped[kMDGUIDSize] = {0};
// Endian-ness swap to match dump processor expectation.
memcpy(identifier_swapped, &identifier[0],
std::min(kMDGUIDSize, identifier.size()));
uint32_t* data1 = reinterpret_cast<uint32_t*>(identifier_swapped);
*data1 = htonl(*data1);
uint16_t* data2 = reinterpret_cast<uint16_t*>(identifier_swapped + 4);
*data2 = htons(*data2);
uint16_t* data3 = reinterpret_cast<uint16_t*>(identifier_swapped + 6);
*data3 = htons(*data3);
return bytes_to_hex_string(identifier_swapped, kMDGUIDSize);
}
// Convert the entire |identifier| data to a lowercase hex string.
static std::string ConvertIdentifierToString(
const std::vector<uint8_t>& identifier) {
return bytes_to_hex_string(&identifier[0], identifier.size(),
/* lowercase */ true);
}
private:
// Storage for the path specified
std::string path_;
};
// End of imports from toolkit/crashreporter/google-breakpad/.
// ----------------------------------------------------------------------------
struct LoadedLibraryInfo {
LoadedLibraryInfo(const char* aName, unsigned long aBaseAddress,
unsigned long aFirstMappingStart,
unsigned long aLastMappingEnd)
: mName(aName),
mBaseAddress(aBaseAddress),
mFirstMappingStart(aFirstMappingStart),
mLastMappingEnd(aLastMappingEnd) {}
std::string mName;
unsigned long mBaseAddress;
unsigned long mFirstMappingStart;
unsigned long mLastMappingEnd;
};
static std::string IDtoUUIDString(const std::vector<uint8_t>& aIdentifier) {
std::string uuid = FileID::ConvertIdentifierToUUIDString(aIdentifier);
// This is '0', not '\0', since it represents the breakpad id age.
uuid += '0';
return uuid;
}
// Return raw Build ID in hex.
static std::string IDtoString(const std::vector<uint8_t>& aIdentifier) {
std::string uuid = FileID::ConvertIdentifierToString(aIdentifier);
return uuid;
}
// Get the ELF file identifier, which will be used for getting the breakpad Id
// and code Id for the binary file pointed by bin_name.
static std::optional<std::vector<uint8_t>> getElfFileIdentifier(
const char* bin_name) {
std::vector<uint8_t> identifier;
identifier.reserve(kDefaultBuildIdSize);
FileID file_id(bin_name);
if (file_id.ElfFileIdentifier(identifier)) {
return identifier;
}
return {};
}
// Get the breakpad Id for the ELF file identifier.
static std::string getBreakpadId(
const std::optional<std::vector<uint8_t>>& aIdentifier) {
if (aIdentifier) {
return IDtoUUIDString(aIdentifier.value());
}
return {};
}
// Get the code Id for the ELF file identifier.
static std::string getCodeId(
const std::optional<std::vector<uint8_t>>& aIdentifier) {
if (aIdentifier) {
return IDtoString(aIdentifier.value());
}
return {};
}
static SharedLibrary SharedLibraryAtPath(const char* path,
unsigned long libStart,
unsigned long libEnd,
unsigned long offset = 0) {
std::string pathStr = path;
size_t pos = pathStr.rfind('/');
std::string nameStr =
(pos != std::string::npos) ? pathStr.substr(pos + 1) : pathStr;
const auto identifier = getElfFileIdentifier(path);
return SharedLibrary(libStart, libEnd, offset, getBreakpadId(identifier),
getCodeId(identifier), nameStr, pathStr, nameStr,
pathStr, std::string{}, "");
}
static int dl_iterate_callback(struct dl_phdr_info* dl_info, size_t size,
void* data) {
auto libInfoList = reinterpret_cast<std::vector<LoadedLibraryInfo>*>(data);
if (dl_info->dlpi_phnum <= 0) return 0;
unsigned long baseAddress = dl_info->dlpi_addr;
unsigned long firstMappingStart = -1;
unsigned long lastMappingEnd = 0;
for (size_t i = 0; i < dl_info->dlpi_phnum; i++) {
if (dl_info->dlpi_phdr[i].p_type != PT_LOAD) {
continue;
}
unsigned long start = dl_info->dlpi_addr + dl_info->dlpi_phdr[i].p_vaddr;
unsigned long end = start + dl_info->dlpi_phdr[i].p_memsz;
if (start < firstMappingStart) {
firstMappingStart = start;
}
if (end > lastMappingEnd) {
lastMappingEnd = end;
}
}
libInfoList->push_back(LoadedLibraryInfo(dl_info->dlpi_name, baseAddress,
firstMappingStart, lastMappingEnd));
return 0;
}
SharedLibraryInfo SharedLibraryInfo::GetInfoForSelf() {
SharedLibraryInfo info;
#if defined(GP_OS_linux)
// We need to find the name of the executable (exeName, exeNameLen) and the
// address of its executable section (exeExeAddr) in the running image.
char exeName[PATH_MAX];
memset(exeName, 0, sizeof(exeName));
ssize_t exeNameLen = readlink("/proc/self/exe", exeName, sizeof(exeName) - 1);
if (exeNameLen == -1) {
// readlink failed for whatever reason. Note this, but keep going.
exeName[0] = '\0';
exeNameLen = 0;
// LOG("SharedLibraryInfo::GetInfoForSelf(): readlink failed");
} else {
// Assert no buffer overflow.
MOZ_RELEASE_ASSERT(exeNameLen >= 0 &&
exeNameLen < static_cast<ssize_t>(sizeof(exeName)));
}
unsigned long exeExeAddr = 0;
#endif
#if defined(GP_OS_android)
// If dl_iterate_phdr doesn't exist, we give up immediately.
if (!dl_iterate_phdr) {
// On ARM Android, dl_iterate_phdr is provided by the custom linker.
// So if libxul was loaded by the system linker (e.g. as part of
// xpcshell when running tests), it won't be available and we should
// not call it.
return info;
}
#endif
#if defined(GP_OS_linux) || defined(GP_OS_android)
// Read info from /proc/self/maps. We ignore most of it.
pid_t pid = mozilla::baseprofiler::profiler_current_process_id().ToNumber();
char path[PATH_MAX];
SprintfLiteral(path, "/proc/%d/maps", pid);
std::ifstream maps(path);
std::string line;
while (std::getline(maps, line)) {
int ret;
unsigned long start;
unsigned long end;
char perm[6 + 1] = "";
unsigned long offset;
char modulePath[PATH_MAX + 1] = "";
ret = sscanf(line.c_str(),
"%lx-%lx %6s %lx %*s %*x %" PATH_MAX_STRING(PATH_MAX) "s\n",
&start, &end, perm, &offset, modulePath);
if (!strchr(perm, 'x')) {
// Ignore non executable entries
continue;
}
if (ret != 5 && ret != 4) {
// LOG("SharedLibraryInfo::GetInfoForSelf(): "
// "reading /proc/self/maps failed");
continue;
}
# if defined(GP_OS_linux)
// Try to establish the main executable's load address.
if (exeNameLen > 0 && strcmp(modulePath, exeName) == 0) {
exeExeAddr = start;
}
# elif defined(GP_OS_android)
// Use /proc/pid/maps to get the dalvik-jit section since it has no
// associated phdrs.
if (0 == strcmp(modulePath, "/dev/ashmem/dalvik-jit-code-cache")) {
info.AddSharedLibrary(
SharedLibraryAtPath(modulePath, start, end, offset));
if (info.GetSize() > 10000) {
// LOG("SharedLibraryInfo::GetInfoForSelf(): "
// "implausibly large number of mappings acquired");
break;
}
}
# endif
}
#endif
std::vector<LoadedLibraryInfo> libInfoList;
// We collect the bulk of the library info using dl_iterate_phdr.
dl_iterate_phdr(dl_iterate_callback, &libInfoList);
for (const auto& libInfo : libInfoList) {
info.AddSharedLibrary(
SharedLibraryAtPath(libInfo.mName.c_str(), libInfo.mFirstMappingStart,
libInfo.mLastMappingEnd,
libInfo.mFirstMappingStart - libInfo.mBaseAddress));
}
#if defined(GP_OS_linux)
// Make another pass over the information we just harvested from
// dl_iterate_phdr. If we see a nameless object mapped at what we earlier
// established to be the main executable's load address, attach the
// executable's name to that entry.
for (size_t i = 0; i < info.GetSize(); i++) {
SharedLibrary& lib = info.GetMutableEntry(i);
if (lib.GetStart() <= exeExeAddr && exeExeAddr <= lib.GetEnd() &&
lib.GetDebugPath().empty()) {
lib = SharedLibraryAtPath(exeName, lib.GetStart(), lib.GetEnd(),
lib.GetOffset());
// We only expect to see one such entry.
break;
}
}
#endif
return info;
}
void SharedLibraryInfo::Initialize() { /* do nothing */ }