Retro68/gcc/libsanitizer/sanitizer_common/sanitizer_linux_libcdep.cc
2017-04-10 13:32:00 +02:00

565 lines
17 KiB
C++

//===-- sanitizer_linux_libcdep.cc ----------------------------------------===//
//
// 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 linux-specific functions from
// sanitizer_libc.h.
//===----------------------------------------------------------------------===//
#include "sanitizer_platform.h"
#if SANITIZER_FREEBSD || SANITIZER_LINUX
#include "sanitizer_allocator_internal.h"
#include "sanitizer_atomic.h"
#include "sanitizer_common.h"
#include "sanitizer_flags.h"
#include "sanitizer_freebsd.h"
#include "sanitizer_linux.h"
#include "sanitizer_placement_new.h"
#include "sanitizer_procmaps.h"
#include "sanitizer_stacktrace.h"
#if SANITIZER_ANDROID || SANITIZER_FREEBSD
#include <dlfcn.h> // for dlsym()
#endif
#include <link.h>
#include <pthread.h>
#include <signal.h>
#include <sys/resource.h>
#if SANITIZER_FREEBSD
#include <pthread_np.h>
#include <osreldate.h>
#define pthread_getattr_np pthread_attr_get_np
#endif
#if SANITIZER_LINUX
#include <sys/prctl.h>
#endif
#if SANITIZER_ANDROID
#include <android/api-level.h>
#endif
#if SANITIZER_ANDROID && __ANDROID_API__ < 21
#include <android/log.h>
#else
#include <syslog.h>
#endif
#if !SANITIZER_ANDROID
#include <elf.h>
#include <unistd.h>
#endif
namespace __sanitizer {
SANITIZER_WEAK_ATTRIBUTE int
real_sigaction(int signum, const void *act, void *oldact);
int internal_sigaction(int signum, const void *act, void *oldact) {
#if !SANITIZER_GO
if (&real_sigaction)
return real_sigaction(signum, act, oldact);
#endif
return sigaction(signum, (const struct sigaction *)act,
(struct sigaction *)oldact);
}
void GetThreadStackTopAndBottom(bool at_initialization, uptr *stack_top,
uptr *stack_bottom) {
CHECK(stack_top);
CHECK(stack_bottom);
if (at_initialization) {
// This is the main thread. Libpthread may not be initialized yet.
struct rlimit rl;
CHECK_EQ(getrlimit(RLIMIT_STACK, &rl), 0);
// Find the mapping that contains a stack variable.
MemoryMappingLayout proc_maps(/*cache_enabled*/true);
uptr start, end, offset;
uptr prev_end = 0;
while (proc_maps.Next(&start, &end, &offset, nullptr, 0,
/* protection */nullptr)) {
if ((uptr)&rl < end)
break;
prev_end = end;
}
CHECK((uptr)&rl >= start && (uptr)&rl < end);
// Get stacksize from rlimit, but clip it so that it does not overlap
// with other mappings.
uptr stacksize = rl.rlim_cur;
if (stacksize > end - prev_end)
stacksize = end - prev_end;
// When running with unlimited stack size, we still want to set some limit.
// The unlimited stack size is caused by 'ulimit -s unlimited'.
// Also, for some reason, GNU make spawns subprocesses with unlimited stack.
if (stacksize > kMaxThreadStackSize)
stacksize = kMaxThreadStackSize;
*stack_top = end;
*stack_bottom = end - stacksize;
return;
}
pthread_attr_t attr;
pthread_attr_init(&attr);
CHECK_EQ(pthread_getattr_np(pthread_self(), &attr), 0);
uptr stacksize = 0;
void *stackaddr = nullptr;
my_pthread_attr_getstack(&attr, &stackaddr, &stacksize);
pthread_attr_destroy(&attr);
CHECK_LE(stacksize, kMaxThreadStackSize); // Sanity check.
*stack_top = (uptr)stackaddr + stacksize;
*stack_bottom = (uptr)stackaddr;
}
#if !SANITIZER_GO
bool SetEnv(const char *name, const char *value) {
void *f = dlsym(RTLD_NEXT, "setenv");
if (!f)
return false;
typedef int(*setenv_ft)(const char *name, const char *value, int overwrite);
setenv_ft setenv_f;
CHECK_EQ(sizeof(setenv_f), sizeof(f));
internal_memcpy(&setenv_f, &f, sizeof(f));
return setenv_f(name, value, 1) == 0;
}
#endif
bool SanitizerSetThreadName(const char *name) {
#ifdef PR_SET_NAME
return 0 == prctl(PR_SET_NAME, (unsigned long)name, 0, 0, 0); // NOLINT
#else
return false;
#endif
}
bool SanitizerGetThreadName(char *name, int max_len) {
#ifdef PR_GET_NAME
char buff[17];
if (prctl(PR_GET_NAME, (unsigned long)buff, 0, 0, 0)) // NOLINT
return false;
internal_strncpy(name, buff, max_len);
name[max_len] = 0;
return true;
#else
return false;
#endif
}
#if !SANITIZER_FREEBSD && !SANITIZER_ANDROID && !SANITIZER_GO
static uptr g_tls_size;
#endif
#ifdef __i386__
# define DL_INTERNAL_FUNCTION __attribute__((regparm(3), stdcall))
#else
# define DL_INTERNAL_FUNCTION
#endif
#if defined(__mips__) || defined(__powerpc64__)
// TlsPreTcbSize includes size of struct pthread_descr and size of tcb
// head structure. It lies before the static tls blocks.
static uptr TlsPreTcbSize() {
# if defined(__mips__)
const uptr kTcbHead = 16; // sizeof (tcbhead_t)
# elif defined(__powerpc64__)
const uptr kTcbHead = 88; // sizeof (tcbhead_t)
# endif
const uptr kTlsAlign = 16;
const uptr kTlsPreTcbSize =
(ThreadDescriptorSize() + kTcbHead + kTlsAlign - 1) & ~(kTlsAlign - 1);
InitTlsSize();
g_tls_size = (g_tls_size + kTlsPreTcbSize + kTlsAlign -1) & ~(kTlsAlign - 1);
return kTlsPreTcbSize;
}
#endif
void InitTlsSize() {
#if !SANITIZER_FREEBSD && !SANITIZER_ANDROID && !SANITIZER_GO
// all current supported platforms have 16 bytes stack alignment
const size_t kStackAlign = 16;
typedef void (*get_tls_func)(size_t*, size_t*) DL_INTERNAL_FUNCTION;
get_tls_func get_tls;
void *get_tls_static_info_ptr = dlsym(RTLD_NEXT, "_dl_get_tls_static_info");
CHECK_EQ(sizeof(get_tls), sizeof(get_tls_static_info_ptr));
internal_memcpy(&get_tls, &get_tls_static_info_ptr,
sizeof(get_tls_static_info_ptr));
CHECK_NE(get_tls, 0);
size_t tls_size = 0;
size_t tls_align = 0;
get_tls(&tls_size, &tls_align);
if (tls_align < kStackAlign)
tls_align = kStackAlign;
g_tls_size = RoundUpTo(tls_size, tls_align);
#endif // !SANITIZER_FREEBSD && !SANITIZER_ANDROID && !SANITIZER_GO
}
#if (defined(__x86_64__) || defined(__i386__) || defined(__mips__) \
|| defined(__aarch64__) || defined(__powerpc64__)) \
&& SANITIZER_LINUX && !SANITIZER_ANDROID
// sizeof(struct pthread) from glibc.
static atomic_uintptr_t kThreadDescriptorSize;
uptr ThreadDescriptorSize() {
uptr val = atomic_load(&kThreadDescriptorSize, memory_order_relaxed);
if (val)
return val;
#if defined(__x86_64__) || defined(__i386__)
#ifdef _CS_GNU_LIBC_VERSION
char buf[64];
uptr len = confstr(_CS_GNU_LIBC_VERSION, buf, sizeof(buf));
if (len < sizeof(buf) && internal_strncmp(buf, "glibc 2.", 8) == 0) {
char *end;
int minor = internal_simple_strtoll(buf + 8, &end, 10);
if (end != buf + 8 && (*end == '\0' || *end == '.')) {
/* sizeof(struct pthread) values from various glibc versions. */
if (SANITIZER_X32)
val = 1728; // Assume only one particular version for x32.
else if (minor <= 3)
val = FIRST_32_SECOND_64(1104, 1696);
else if (minor == 4)
val = FIRST_32_SECOND_64(1120, 1728);
else if (minor == 5)
val = FIRST_32_SECOND_64(1136, 1728);
else if (minor <= 9)
val = FIRST_32_SECOND_64(1136, 1712);
else if (minor == 10)
val = FIRST_32_SECOND_64(1168, 1776);
else if (minor <= 12)
val = FIRST_32_SECOND_64(1168, 2288);
else if (minor == 13)
val = FIRST_32_SECOND_64(1168, 2304);
else
val = FIRST_32_SECOND_64(1216, 2304);
}
if (val)
atomic_store(&kThreadDescriptorSize, val, memory_order_relaxed);
return val;
}
#endif
#elif defined(__mips__)
// TODO(sagarthakur): add more values as per different glibc versions.
val = FIRST_32_SECOND_64(1152, 1776);
if (val)
atomic_store(&kThreadDescriptorSize, val, memory_order_relaxed);
return val;
#elif defined(__aarch64__)
// The sizeof (struct pthread) is the same from GLIBC 2.17 to 2.22.
val = 1776;
atomic_store(&kThreadDescriptorSize, val, memory_order_relaxed);
return val;
#elif defined(__powerpc64__)
val = 1776; // from glibc.ppc64le 2.20-8.fc21
atomic_store(&kThreadDescriptorSize, val, memory_order_relaxed);
return val;
#endif
return 0;
}
// The offset at which pointer to self is located in the thread descriptor.
const uptr kThreadSelfOffset = FIRST_32_SECOND_64(8, 16);
uptr ThreadSelfOffset() {
return kThreadSelfOffset;
}
uptr ThreadSelf() {
uptr descr_addr;
# if defined(__i386__)
asm("mov %%gs:%c1,%0" : "=r"(descr_addr) : "i"(kThreadSelfOffset));
# elif defined(__x86_64__)
asm("mov %%fs:%c1,%0" : "=r"(descr_addr) : "i"(kThreadSelfOffset));
# elif defined(__mips__)
// MIPS uses TLS variant I. The thread pointer (in hardware register $29)
// points to the end of the TCB + 0x7000. The pthread_descr structure is
// immediately in front of the TCB. TlsPreTcbSize() includes the size of the
// TCB and the size of pthread_descr.
const uptr kTlsTcbOffset = 0x7000;
uptr thread_pointer;
asm volatile(".set push;\
.set mips64r2;\
rdhwr %0,$29;\
.set pop" : "=r" (thread_pointer));
descr_addr = thread_pointer - kTlsTcbOffset - TlsPreTcbSize();
# elif defined(__aarch64__)
descr_addr = reinterpret_cast<uptr>(__builtin_thread_pointer());
# elif defined(__powerpc64__)
// PPC64LE uses TLS variant I. The thread pointer (in GPR 13)
// points to the end of the TCB + 0x7000. The pthread_descr structure is
// immediately in front of the TCB. TlsPreTcbSize() includes the size of the
// TCB and the size of pthread_descr.
const uptr kTlsTcbOffset = 0x7000;
uptr thread_pointer;
asm("addi %0,13,%1" : "=r"(thread_pointer) : "I"(-kTlsTcbOffset));
descr_addr = thread_pointer - TlsPreTcbSize();
# else
# error "unsupported CPU arch"
# endif
return descr_addr;
}
#endif // (x86_64 || i386 || MIPS) && SANITIZER_LINUX
#if SANITIZER_FREEBSD
static void **ThreadSelfSegbase() {
void **segbase = 0;
# if defined(__i386__)
// sysarch(I386_GET_GSBASE, segbase);
__asm __volatile("mov %%gs:0, %0" : "=r" (segbase));
# elif defined(__x86_64__)
// sysarch(AMD64_GET_FSBASE, segbase);
__asm __volatile("movq %%fs:0, %0" : "=r" (segbase));
# else
# error "unsupported CPU arch for FreeBSD platform"
# endif
return segbase;
}
uptr ThreadSelf() {
return (uptr)ThreadSelfSegbase()[2];
}
#endif // SANITIZER_FREEBSD
#if !SANITIZER_GO
static void GetTls(uptr *addr, uptr *size) {
#if SANITIZER_LINUX && !SANITIZER_ANDROID
# if defined(__x86_64__) || defined(__i386__)
*addr = ThreadSelf();
*size = GetTlsSize();
*addr -= *size;
*addr += ThreadDescriptorSize();
# elif defined(__mips__) || defined(__aarch64__) || defined(__powerpc64__)
*addr = ThreadSelf();
*size = GetTlsSize();
# else
*addr = 0;
*size = 0;
# endif
#elif SANITIZER_FREEBSD
void** segbase = ThreadSelfSegbase();
*addr = 0;
*size = 0;
if (segbase != 0) {
// tcbalign = 16
// tls_size = round(tls_static_space, tcbalign);
// dtv = segbase[1];
// dtv[2] = segbase - tls_static_space;
void **dtv = (void**) segbase[1];
*addr = (uptr) dtv[2];
*size = (*addr == 0) ? 0 : ((uptr) segbase[0] - (uptr) dtv[2]);
}
#elif SANITIZER_ANDROID
*addr = 0;
*size = 0;
#else
# error "Unknown OS"
#endif
}
#endif
#if !SANITIZER_GO
uptr GetTlsSize() {
#if SANITIZER_FREEBSD || SANITIZER_ANDROID
uptr addr, size;
GetTls(&addr, &size);
return size;
#else
return g_tls_size;
#endif
}
#endif
void GetThreadStackAndTls(bool main, uptr *stk_addr, uptr *stk_size,
uptr *tls_addr, uptr *tls_size) {
#if SANITIZER_GO
// Stub implementation for Go.
*stk_addr = *stk_size = *tls_addr = *tls_size = 0;
#else
GetTls(tls_addr, tls_size);
uptr stack_top, stack_bottom;
GetThreadStackTopAndBottom(main, &stack_top, &stack_bottom);
*stk_addr = stack_bottom;
*stk_size = stack_top - stack_bottom;
if (!main) {
// If stack and tls intersect, make them non-intersecting.
if (*tls_addr > *stk_addr && *tls_addr < *stk_addr + *stk_size) {
CHECK_GT(*tls_addr + *tls_size, *stk_addr);
CHECK_LE(*tls_addr + *tls_size, *stk_addr + *stk_size);
*stk_size -= *tls_size;
*tls_addr = *stk_addr + *stk_size;
}
}
#endif
}
# if !SANITIZER_FREEBSD
typedef ElfW(Phdr) Elf_Phdr;
# elif SANITIZER_WORDSIZE == 32 && __FreeBSD_version <= 902001 // v9.2
# define Elf_Phdr XElf32_Phdr
# define dl_phdr_info xdl_phdr_info
# define dl_iterate_phdr(c, b) xdl_iterate_phdr((c), (b))
# endif
struct DlIteratePhdrData {
LoadedModule *modules;
uptr current_n;
bool first;
uptr max_n;
string_predicate_t filter;
};
static int dl_iterate_phdr_cb(dl_phdr_info *info, size_t size, void *arg) {
DlIteratePhdrData *data = (DlIteratePhdrData*)arg;
if (data->current_n == data->max_n)
return 0;
InternalScopedString module_name(kMaxPathLength);
if (data->first) {
data->first = false;
// First module is the binary itself.
ReadBinaryNameCached(module_name.data(), module_name.size());
} else if (info->dlpi_name) {
module_name.append("%s", info->dlpi_name);
}
if (module_name[0] == '\0')
return 0;
if (data->filter && !data->filter(module_name.data()))
return 0;
LoadedModule *cur_module = &data->modules[data->current_n];
cur_module->set(module_name.data(), info->dlpi_addr);
data->current_n++;
for (int i = 0; i < info->dlpi_phnum; i++) {
const Elf_Phdr *phdr = &info->dlpi_phdr[i];
if (phdr->p_type == PT_LOAD) {
uptr cur_beg = info->dlpi_addr + phdr->p_vaddr;
uptr cur_end = cur_beg + phdr->p_memsz;
bool executable = phdr->p_flags & PF_X;
cur_module->addAddressRange(cur_beg, cur_end, executable);
}
}
return 0;
}
#if SANITIZER_ANDROID && __ANDROID_API__ < 21
extern "C" __attribute__((weak)) int dl_iterate_phdr(
int (*)(struct dl_phdr_info *, size_t, void *), void *);
#endif
uptr GetListOfModules(LoadedModule *modules, uptr max_modules,
string_predicate_t filter) {
#if SANITIZER_ANDROID && __ANDROID_API__ <= 22
u32 api_level = AndroidGetApiLevel();
// Fall back to /proc/maps if dl_iterate_phdr is unavailable or broken.
// The runtime check allows the same library to work with
// both K and L (and future) Android releases.
if (api_level <= ANDROID_LOLLIPOP_MR1) { // L or earlier
MemoryMappingLayout memory_mapping(false);
return memory_mapping.DumpListOfModules(modules, max_modules, filter);
}
#endif
CHECK(modules);
DlIteratePhdrData data = {modules, 0, true, max_modules, filter};
dl_iterate_phdr(dl_iterate_phdr_cb, &data);
return data.current_n;
}
// getrusage does not give us the current RSS, only the max RSS.
// Still, this is better than nothing if /proc/self/statm is not available
// for some reason, e.g. due to a sandbox.
static uptr GetRSSFromGetrusage() {
struct rusage usage;
if (getrusage(RUSAGE_SELF, &usage)) // Failed, probably due to a sandbox.
return 0;
return usage.ru_maxrss << 10; // ru_maxrss is in Kb.
}
uptr GetRSS() {
if (!common_flags()->can_use_proc_maps_statm)
return GetRSSFromGetrusage();
fd_t fd = OpenFile("/proc/self/statm", RdOnly);
if (fd == kInvalidFd)
return GetRSSFromGetrusage();
char buf[64];
uptr len = internal_read(fd, buf, sizeof(buf) - 1);
internal_close(fd);
if ((sptr)len <= 0)
return 0;
buf[len] = 0;
// The format of the file is:
// 1084 89 69 11 0 79 0
// We need the second number which is RSS in pages.
char *pos = buf;
// Skip the first number.
while (*pos >= '0' && *pos <= '9')
pos++;
// Skip whitespaces.
while (!(*pos >= '0' && *pos <= '9') && *pos != 0)
pos++;
// Read the number.
uptr rss = 0;
while (*pos >= '0' && *pos <= '9')
rss = rss * 10 + *pos++ - '0';
return rss * GetPageSizeCached();
}
// 64-bit Android targets don't provide the deprecated __android_log_write.
// Starting with the L release, syslog() works and is preferable to
// __android_log_write.
#if SANITIZER_LINUX
#if SANITIZER_ANDROID
static atomic_uint8_t android_log_initialized;
void AndroidLogInit() {
atomic_store(&android_log_initialized, 1, memory_order_release);
}
static bool IsSyslogAvailable() {
return atomic_load(&android_log_initialized, memory_order_acquire);
}
#else
void AndroidLogInit() {}
static bool IsSyslogAvailable() { return true; }
#endif // SANITIZER_ANDROID
static void WriteOneLineToSyslog(const char *s) {
#if SANITIZER_ANDROID &&__ANDROID_API__ < 21
__android_log_write(ANDROID_LOG_INFO, NULL, s);
#else
syslog(LOG_INFO, "%s", s);
#endif
}
void WriteToSyslog(const char *buffer) {
if (!IsSyslogAvailable())
return;
char *copy = internal_strdup(buffer);
char *p = copy;
char *q;
// syslog, at least on Android, has an implicit message length limit.
// Print one line at a time.
do {
q = internal_strchr(p, '\n');
if (q)
*q = '\0';
WriteOneLineToSyslog(p);
if (q)
p = q + 1;
} while (q);
InternalFree(copy);
}
#endif // SANITIZER_LINUX
} // namespace __sanitizer
#endif // SANITIZER_FREEBSD || SANITIZER_LINUX