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//===-- sanitizer_posix.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 POSIX-specific functions from
// sanitizer_libc.h.
//===----------------------------------------------------------------------===//
#include "sanitizer_platform.h"
#if SANITIZER_POSIX
#include "sanitizer_common.h"
#include "sanitizer_libc.h"
#include "sanitizer_procmaps.h"
#include "sanitizer_stacktrace.h"
#include <fcntl.h>
#include <signal.h>
#include <sys/mman.h>
#if SANITIZER_LINUX
#include <sys/utsname.h>
#endif
#if SANITIZER_LINUX && !SANITIZER_ANDROID
#include <sys/personality.h>
#endif
#if SANITIZER_FREEBSD
// The MAP_NORESERVE define has been removed in FreeBSD 11.x, and even before
// that, it was never implemented. So just define it to zero.
#undef MAP_NORESERVE
#define MAP_NORESERVE 0
#endif
namespace __sanitizer {
// ------------- sanitizer_common.h
uptr GetMmapGranularity() {
return GetPageSize();
}
#if SANITIZER_WORDSIZE == 32
// Take care of unusable kernel area in top gigabyte.
static uptr GetKernelAreaSize() {
#if SANITIZER_LINUX && !SANITIZER_X32
const uptr gbyte = 1UL << 30;
// Firstly check if there are writable segments
// mapped to top gigabyte (e.g. stack).
MemoryMappingLayout proc_maps(/*cache_enabled*/true);
uptr end, prot;
while (proc_maps.Next(/*start*/0, &end,
/*offset*/0, /*filename*/0,
/*filename_size*/0, &prot)) {
if ((end >= 3 * gbyte)
&& (prot & MemoryMappingLayout::kProtectionWrite) != 0)
return 0;
}
#if !SANITIZER_ANDROID
// Even if nothing is mapped, top Gb may still be accessible
// if we are running on 64-bit kernel.
// Uname may report misleading results if personality type
// is modified (e.g. under schroot) so check this as well.
struct utsname uname_info;
int pers = personality(0xffffffffUL);
if (!(pers & PER_MASK)
&& uname(&uname_info) == 0
&& internal_strstr(uname_info.machine, "64"))
return 0;
#endif // SANITIZER_ANDROID
// Top gigabyte is reserved for kernel.
return gbyte;
#else
return 0;
#endif // SANITIZER_LINUX && !SANITIZER_X32
}
#endif // SANITIZER_WORDSIZE == 32
uptr GetMaxVirtualAddress() {
#if SANITIZER_WORDSIZE == 64
# if defined(__powerpc64__) || defined(__aarch64__)
// On PowerPC64 we have two different address space layouts: 44- and 46-bit.
// We somehow need to figure out which one we are using now and choose
// one of 0x00000fffffffffffUL and 0x00003fffffffffffUL.
// Note that with 'ulimit -s unlimited' the stack is moved away from the top
// of the address space, so simply checking the stack address is not enough.
// This should (does) work for both PowerPC64 Endian modes.
// Similarly, aarch64 has multiple address space layouts: 39, 42 and 47-bit.
return (1ULL << (MostSignificantSetBitIndex(GET_CURRENT_FRAME()) + 1)) - 1;
# elif defined(__mips64)
return (1ULL << 40) - 1; // 0x000000ffffffffffUL;
# else
return (1ULL << 47) - 1; // 0x00007fffffffffffUL;
# endif
#else // SANITIZER_WORDSIZE == 32
uptr res = (1ULL << 32) - 1; // 0xffffffff;
if (!common_flags()->full_address_space)
res -= GetKernelAreaSize();
CHECK_LT(reinterpret_cast<uptr>(&res), res);
return res;
#endif // SANITIZER_WORDSIZE
}
void *MmapOrDie(uptr size, const char *mem_type) {
size = RoundUpTo(size, GetPageSizeCached());
uptr res = internal_mmap(0, size,
PROT_READ | PROT_WRITE,
MAP_PRIVATE | MAP_ANON, -1, 0);
int reserrno;
if (internal_iserror(res, &reserrno)) {
static int recursion_count;
if (recursion_count) {
// The Report() and CHECK calls below may call mmap recursively and fail.
// If we went into recursion, just die.
RawWrite("ERROR: Failed to mmap\n");
Die();
}
recursion_count++;
Report("ERROR: %s failed to "
"allocate 0x%zx (%zd) bytes of %s (errno: %d)\n",
SanitizerToolName, size, size, mem_type, reserrno);
DumpProcessMap();
CHECK("unable to mmap" && 0);
}
IncreaseTotalMmap(size);
return (void *)res;
}
void UnmapOrDie(void *addr, uptr size) {
if (!addr || !size) return;
uptr res = internal_munmap(addr, size);
if (internal_iserror(res)) {
Report("ERROR: %s failed to deallocate 0x%zx (%zd) bytes at address %p\n",
SanitizerToolName, size, size, addr);
CHECK("unable to unmap" && 0);
}
DecreaseTotalMmap(size);
}
void *MmapNoReserveOrDie(uptr size, const char *mem_type) {
uptr PageSize = GetPageSizeCached();
uptr p = internal_mmap(0,
RoundUpTo(size, PageSize),
PROT_READ | PROT_WRITE,
MAP_PRIVATE | MAP_ANON | MAP_NORESERVE,
-1, 0);
int reserrno;
if (internal_iserror(p, &reserrno)) {
Report("ERROR: %s failed to "
"allocate noreserve 0x%zx (%zd) bytes for '%s' (errno: %d)\n",
SanitizerToolName, size, size, mem_type, reserrno);
CHECK("unable to mmap" && 0);
}
IncreaseTotalMmap(size);
return (void *)p;
}
void *MmapFixedNoReserve(uptr fixed_addr, uptr size) {
uptr PageSize = GetPageSizeCached();
uptr p = internal_mmap((void*)(fixed_addr & ~(PageSize - 1)),
RoundUpTo(size, PageSize),
PROT_READ | PROT_WRITE,
MAP_PRIVATE | MAP_ANON | MAP_FIXED | MAP_NORESERVE,
-1, 0);
int reserrno;
if (internal_iserror(p, &reserrno))
Report("ERROR: %s failed to "
"allocate 0x%zx (%zd) bytes at address %zx (errno: %d)\n",
SanitizerToolName, size, size, fixed_addr, reserrno);
IncreaseTotalMmap(size);
return (void *)p;
}
void *MmapFixedOrDie(uptr fixed_addr, uptr size) {
uptr PageSize = GetPageSizeCached();
uptr p = internal_mmap((void*)(fixed_addr & ~(PageSize - 1)),
RoundUpTo(size, PageSize),
PROT_READ | PROT_WRITE,
MAP_PRIVATE | MAP_ANON | MAP_FIXED,
-1, 0);
int reserrno;
if (internal_iserror(p, &reserrno)) {
Report("ERROR: %s failed to "
"allocate 0x%zx (%zd) bytes at address %zx (errno: %d)\n",
SanitizerToolName, size, size, fixed_addr, reserrno);
CHECK("unable to mmap" && 0);
}
IncreaseTotalMmap(size);
return (void *)p;
}
void *Mprotect(uptr fixed_addr, uptr size) {
return (void *)internal_mmap((void*)fixed_addr, size,
PROT_NONE,
MAP_PRIVATE | MAP_ANON | MAP_FIXED |
MAP_NORESERVE, -1, 0);
}
uptr OpenFile(const char *filename, FileAccessMode mode) {
int flags;
switch (mode) {
case RdOnly: flags = O_RDONLY; break;
case WrOnly: flags = O_WRONLY | O_CREAT; break;
case RdWr: flags = O_RDWR | O_CREAT; break;
}
return internal_open(filename, flags, 0660);
}
void *MapFileToMemory(const char *file_name, uptr *buff_size) {
uptr openrv = OpenFile(file_name, RdOnly);
CHECK(!internal_iserror(openrv));
fd_t fd = openrv;
uptr fsize = internal_filesize(fd);
CHECK_NE(fsize, (uptr)-1);
CHECK_GT(fsize, 0);
*buff_size = RoundUpTo(fsize, GetPageSizeCached());
uptr map = internal_mmap(0, *buff_size, PROT_READ, MAP_PRIVATE, fd, 0);
return internal_iserror(map) ? 0 : (void *)map;
}
void *MapWritableFileToMemory(void *addr, uptr size, uptr fd, uptr offset) {
uptr flags = MAP_SHARED;
if (addr) flags |= MAP_FIXED;
uptr p = internal_mmap(addr, size, PROT_READ | PROT_WRITE, flags, fd, offset);
int mmap_errno = 0;
if (internal_iserror(p, &mmap_errno)) {
Printf("could not map writable file (%zd, %zu, %zu): %zd, errno: %d\n",
fd, offset, size, p, mmap_errno);
return 0;
}
return (void *)p;
}
static inline bool IntervalsAreSeparate(uptr start1, uptr end1,
uptr start2, uptr end2) {
CHECK(start1 <= end1);
CHECK(start2 <= end2);
return (end1 < start2) || (end2 < start1);
}
// FIXME: this is thread-unsafe, but should not cause problems most of the time.
// When the shadow is mapped only a single thread usually exists (plus maybe
// several worker threads on Mac, which aren't expected to map big chunks of
// memory).
bool MemoryRangeIsAvailable(uptr range_start, uptr range_end) {
MemoryMappingLayout proc_maps(/*cache_enabled*/true);
uptr start, end;
while (proc_maps.Next(&start, &end,
/*offset*/0, /*filename*/0, /*filename_size*/0,
/*protection*/0)) {
CHECK_NE(0, end);
if (!IntervalsAreSeparate(start, end - 1, range_start, range_end))
return false;
}
return true;
}
void DumpProcessMap() {
MemoryMappingLayout proc_maps(/*cache_enabled*/true);
uptr start, end;
const sptr kBufSize = 4095;
char *filename = (char*)MmapOrDie(kBufSize, __func__);
Report("Process memory map follows:\n");
while (proc_maps.Next(&start, &end, /* file_offset */0,
filename, kBufSize, /* protection */0)) {
Printf("\t%p-%p\t%s\n", (void*)start, (void*)end, filename);
}
Report("End of process memory map.\n");
UnmapOrDie(filename, kBufSize);
}
const char *GetPwd() {
return GetEnv("PWD");
}
char *FindPathToBinary(const char *name) {
const char *path = GetEnv("PATH");
if (!path)
return 0;
uptr name_len = internal_strlen(name);
InternalScopedBuffer<char> buffer(kMaxPathLength);
const char *beg = path;
while (true) {
const char *end = internal_strchrnul(beg, ':');
uptr prefix_len = end - beg;
if (prefix_len + name_len + 2 <= kMaxPathLength) {
internal_memcpy(buffer.data(), beg, prefix_len);
buffer[prefix_len] = '/';
internal_memcpy(&buffer[prefix_len + 1], name, name_len);
buffer[prefix_len + 1 + name_len] = '\0';
if (FileExists(buffer.data()))
return internal_strdup(buffer.data());
}
if (*end == '\0') break;
beg = end + 1;
}
return 0;
}
bool IsPathSeparator(const char c) {
return c == '/';
}
bool IsAbsolutePath(const char *path) {
return path != nullptr && IsPathSeparator(path[0]);
}
void ReportFile::Write(const char *buffer, uptr length) {
SpinMutexLock l(mu);
static const char *kWriteError =
"ReportFile::Write() can't output requested buffer!\n";
ReopenIfNecessary();
if (length != internal_write(fd, buffer, length)) {
internal_write(fd, kWriteError, internal_strlen(kWriteError));
Die();
}
}
bool GetCodeRangeForFile(const char *module, uptr *start, uptr *end) {
uptr s, e, off, prot;
InternalScopedString buff(kMaxPathLength);
MemoryMappingLayout proc_maps(/*cache_enabled*/false);
while (proc_maps.Next(&s, &e, &off, buff.data(), buff.size(), &prot)) {
if ((prot & MemoryMappingLayout::kProtectionExecute) != 0
&& internal_strcmp(module, buff.data()) == 0) {
*start = s;
*end = e;
return true;
}
}
return false;
}
SignalContext SignalContext::Create(void *siginfo, void *context) {
uptr addr = (uptr)((siginfo_t*)siginfo)->si_addr;
uptr pc, sp, bp;
GetPcSpBp(context, &pc, &sp, &bp);
return SignalContext(context, addr, pc, sp, bp);
}
} // namespace __sanitizer
#endif // SANITIZER_POSIX