llvm-project/compiler-rt/lib/sanitizer_common/sanitizer_mac.cc

236 lines
7.3 KiB
C++

//===-- sanitizer_mac.cc --------------------------------------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file is shared between AddressSanitizer and ThreadSanitizer
// run-time libraries and implements mac-specific functions from
// sanitizer_libc.h.
//===----------------------------------------------------------------------===//
#ifdef __APPLE__
#include "sanitizer_common.h"
#include "sanitizer_internal_defs.h"
#include "sanitizer_libc.h"
#include "sanitizer_procmaps.h"
#include <crt_externs.h> // for _NSGetEnviron
#include <fcntl.h>
#include <mach-o/dyld.h>
#include <mach-o/loader.h>
#include <pthread.h>
#include <sched.h>
#include <sys/mman.h>
#include <sys/resource.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <unistd.h>
namespace __sanitizer {
// ---------------------- sanitizer_libc.h
void *internal_mmap(void *addr, size_t length, int prot, int flags,
int fd, u64 offset) {
return mmap(addr, length, prot, flags, fd, offset);
}
int internal_munmap(void *addr, uptr length) {
return munmap(addr, length);
}
int internal_close(fd_t fd) {
return close(fd);
}
fd_t internal_open(const char *filename, bool write) {
return open(filename,
write ? O_WRONLY | O_CREAT : O_RDONLY, 0660);
}
uptr internal_read(fd_t fd, void *buf, uptr count) {
return read(fd, buf, count);
}
uptr internal_write(fd_t fd, const void *buf, uptr count) {
return write(fd, buf, count);
}
uptr internal_filesize(fd_t fd) {
struct stat st;
if (fstat(fd, &st))
return -1;
return (uptr)st.st_size;
}
int internal_dup2(int oldfd, int newfd) {
return dup2(oldfd, newfd);
}
uptr internal_readlink(const char *path, char *buf, uptr bufsize) {
return readlink(path, buf, bufsize);
}
int internal_sched_yield() {
return sched_yield();
}
// ----------------- sanitizer_common.h
void GetThreadStackTopAndBottom(bool at_initialization, uptr *stack_top,
uptr *stack_bottom) {
CHECK(stack_top);
CHECK(stack_bottom);
uptr stacksize = pthread_get_stacksize_np(pthread_self());
void *stackaddr = pthread_get_stackaddr_np(pthread_self());
*stack_top = (uptr)stackaddr;
*stack_bottom = *stack_top - stacksize;
}
const char *GetEnv(const char *name) {
char ***env_ptr = _NSGetEnviron();
CHECK(env_ptr);
char **environ = *env_ptr;
CHECK(environ);
uptr name_len = internal_strlen(name);
while (*environ != 0) {
uptr len = internal_strlen(*environ);
if (len > name_len) {
const char *p = *environ;
if (!internal_memcmp(p, name, name_len) &&
p[name_len] == '=') { // Match.
return *environ + name_len + 1; // String starting after =.
}
}
environ++;
}
return 0;
}
// ----------------- sanitizer_procmaps.h
MemoryMappingLayout::MemoryMappingLayout() {
Reset();
}
MemoryMappingLayout::~MemoryMappingLayout() {
}
// More information about Mach-O headers can be found in mach-o/loader.h
// Each Mach-O image has a header (mach_header or mach_header_64) starting with
// a magic number, and a list of linker load commands directly following the
// header.
// A load command is at least two 32-bit words: the command type and the
// command size in bytes. We're interested only in segment load commands
// (LC_SEGMENT and LC_SEGMENT_64), which tell that a part of the file is mapped
// into the task's address space.
// The |vmaddr|, |vmsize| and |fileoff| fields of segment_command or
// segment_command_64 correspond to the memory address, memory size and the
// file offset of the current memory segment.
// Because these fields are taken from the images as is, one needs to add
// _dyld_get_image_vmaddr_slide() to get the actual addresses at runtime.
void MemoryMappingLayout::Reset() {
// Count down from the top.
// TODO(glider): as per man 3 dyld, iterating over the headers with
// _dyld_image_count is thread-unsafe. We need to register callbacks for
// adding and removing images which will invalidate the MemoryMappingLayout
// state.
current_image_ = _dyld_image_count();
current_load_cmd_count_ = -1;
current_load_cmd_addr_ = 0;
current_magic_ = 0;
}
// Next and NextSegmentLoad were inspired by base/sysinfo.cc in
// Google Perftools, http://code.google.com/p/google-perftools.
// NextSegmentLoad scans the current image for the next segment load command
// and returns the start and end addresses and file offset of the corresponding
// segment.
// Note that the segment addresses are not necessarily sorted.
template<u32 kLCSegment, typename SegmentCommand>
bool MemoryMappingLayout::NextSegmentLoad(
uptr *start, uptr *end, uptr *offset,
char filename[], uptr filename_size) {
const char* lc = current_load_cmd_addr_;
current_load_cmd_addr_ += ((const load_command *)lc)->cmdsize;
if (((const load_command *)lc)->cmd == kLCSegment) {
const sptr dlloff = _dyld_get_image_vmaddr_slide(current_image_);
const SegmentCommand* sc = (const SegmentCommand *)lc;
if (start) *start = sc->vmaddr + dlloff;
if (end) *end = sc->vmaddr + sc->vmsize + dlloff;
if (offset) *offset = sc->fileoff;
if (filename) {
internal_strncpy(filename, _dyld_get_image_name(current_image_),
filename_size);
}
return true;
}
return false;
}
bool MemoryMappingLayout::Next(uptr *start, uptr *end, uptr *offset,
char filename[], uptr filename_size) {
for (; current_image_ >= 0; current_image_--) {
const mach_header* hdr = _dyld_get_image_header(current_image_);
if (!hdr) continue;
if (current_load_cmd_count_ < 0) {
// Set up for this image;
current_load_cmd_count_ = hdr->ncmds;
current_magic_ = hdr->magic;
switch (current_magic_) {
#ifdef MH_MAGIC_64
case MH_MAGIC_64: {
current_load_cmd_addr_ = (char*)hdr + sizeof(mach_header_64);
break;
}
#endif
case MH_MAGIC: {
current_load_cmd_addr_ = (char*)hdr + sizeof(mach_header);
break;
}
default: {
continue;
}
}
}
for (; current_load_cmd_count_ >= 0; current_load_cmd_count_--) {
switch (current_magic_) {
// current_magic_ may be only one of MH_MAGIC, MH_MAGIC_64.
#ifdef MH_MAGIC_64
case MH_MAGIC_64: {
if (NextSegmentLoad<LC_SEGMENT_64, struct segment_command_64>(
start, end, offset, filename, filename_size))
return true;
break;
}
#endif
case MH_MAGIC: {
if (NextSegmentLoad<LC_SEGMENT, struct segment_command>(
start, end, offset, filename, filename_size))
return true;
break;
}
}
}
// If we get here, no more load_cmd's in this image talk about
// segments. Go on to the next image.
}
return false;
}
bool MemoryMappingLayout::GetObjectNameAndOffset(uptr addr, uptr *offset,
char filename[],
uptr filename_size) {
return IterateForObjectNameAndOffset(addr, offset, filename, filename_size);
}
} // namespace __sanitizer
#endif // __APPLE__