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

347 lines
11 KiB
C++

//===-- tsan_platform_linux.cc --------------------------------------------===//
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file is a part of ThreadSanitizer (TSan), a race detector.
//
// Linux- and FreeBSD-specific code.
//===----------------------------------------------------------------------===//
#include "sanitizer_common/sanitizer_platform.h"
#if SANITIZER_LINUX || SANITIZER_FREEBSD
#include "sanitizer_common/sanitizer_common.h"
#include "sanitizer_common/sanitizer_libc.h"
#include "sanitizer_common/sanitizer_posix.h"
#include "sanitizer_common/sanitizer_procmaps.h"
#include "sanitizer_common/sanitizer_stoptheworld.h"
#include "sanitizer_common/sanitizer_stackdepot.h"
#include "tsan_platform.h"
#include "tsan_rtl.h"
#include "tsan_flags.h"
#include <fcntl.h>
#include <pthread.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdarg.h>
#include <sys/mman.h>
#include <sys/syscall.h>
#include <sys/socket.h>
#include <sys/time.h>
#include <sys/types.h>
#include <sys/resource.h>
#include <sys/stat.h>
#include <unistd.h>
#include <errno.h>
#include <sched.h>
#include <dlfcn.h>
#if SANITIZER_LINUX
#define __need_res_state
#include <resolv.h>
#endif
#ifdef sa_handler
# undef sa_handler
#endif
#ifdef sa_sigaction
# undef sa_sigaction
#endif
#if SANITIZER_FREEBSD
extern "C" void *__libc_stack_end;
void *__libc_stack_end = 0;
#endif
#if SANITIZER_LINUX && defined(__aarch64__)
void InitializeGuardPtr() __attribute__((visibility("hidden")));
#endif
namespace __tsan {
static uptr g_data_start;
static uptr g_data_end;
enum {
MemTotal = 0,
MemShadow = 1,
MemMeta = 2,
MemFile = 3,
MemMmap = 4,
MemTrace = 5,
MemHeap = 6,
MemOther = 7,
MemCount = 8,
};
void FillProfileCallback(uptr p, uptr rss, bool file,
uptr *mem, uptr stats_size) {
mem[MemTotal] += rss;
if (p >= kShadowBeg && p < kShadowEnd)
mem[MemShadow] += rss;
else if (p >= kMetaShadowBeg && p < kMetaShadowEnd)
mem[MemMeta] += rss;
#ifndef SANITIZER_GO
else if (p >= kHeapMemBeg && p < kHeapMemEnd)
mem[MemHeap] += rss;
else if (p >= kLoAppMemBeg && p < kLoAppMemEnd)
mem[file ? MemFile : MemMmap] += rss;
else if (p >= kHiAppMemBeg && p < kHiAppMemEnd)
mem[file ? MemFile : MemMmap] += rss;
#else
else if (p >= kAppMemBeg && p < kAppMemEnd)
mem[file ? MemFile : MemMmap] += rss;
#endif
else if (p >= kTraceMemBeg && p < kTraceMemEnd)
mem[MemTrace] += rss;
else
mem[MemOther] += rss;
}
void WriteMemoryProfile(char *buf, uptr buf_size, uptr nthread, uptr nlive) {
uptr mem[MemCount] = {};
__sanitizer::GetMemoryProfile(FillProfileCallback, mem, 7);
StackDepotStats *stacks = StackDepotGetStats();
internal_snprintf(buf, buf_size,
"RSS %zd MB: shadow:%zd meta:%zd file:%zd mmap:%zd"
" trace:%zd heap:%zd other:%zd stacks=%zd[%zd] nthr=%zd/%zd\n",
mem[MemTotal] >> 20, mem[MemShadow] >> 20, mem[MemMeta] >> 20,
mem[MemFile] >> 20, mem[MemMmap] >> 20, mem[MemTrace] >> 20,
mem[MemHeap] >> 20, mem[MemOther] >> 20,
stacks->allocated >> 20, stacks->n_uniq_ids,
nlive, nthread);
}
#if SANITIZER_LINUX
void FlushShadowMemoryCallback(
const SuspendedThreadsList &suspended_threads_list,
void *argument) {
FlushUnneededShadowMemory(kShadowBeg, kShadowEnd - kShadowBeg);
}
#endif
void FlushShadowMemory() {
#if SANITIZER_LINUX
StopTheWorld(FlushShadowMemoryCallback, 0);
#endif
}
#ifndef SANITIZER_GO
// Mark shadow for .rodata sections with the special kShadowRodata marker.
// Accesses to .rodata can't race, so this saves time, memory and trace space.
static void MapRodata() {
// First create temp file.
const char *tmpdir = GetEnv("TMPDIR");
if (tmpdir == 0)
tmpdir = GetEnv("TEST_TMPDIR");
#ifdef P_tmpdir
if (tmpdir == 0)
tmpdir = P_tmpdir;
#endif
if (tmpdir == 0)
return;
char name[256];
internal_snprintf(name, sizeof(name), "%s/tsan.rodata.%d",
tmpdir, (int)internal_getpid());
uptr openrv = internal_open(name, O_RDWR | O_CREAT | O_EXCL, 0600);
if (internal_iserror(openrv))
return;
internal_unlink(name); // Unlink it now, so that we can reuse the buffer.
fd_t fd = openrv;
// Fill the file with kShadowRodata.
const uptr kMarkerSize = 512 * 1024 / sizeof(u64);
InternalScopedBuffer<u64> marker(kMarkerSize);
// volatile to prevent insertion of memset
for (volatile u64 *p = marker.data(); p < marker.data() + kMarkerSize; p++)
*p = kShadowRodata;
internal_write(fd, marker.data(), marker.size());
// Map the file into memory.
uptr page = internal_mmap(0, GetPageSizeCached(), PROT_READ | PROT_WRITE,
MAP_PRIVATE | MAP_ANONYMOUS, fd, 0);
if (internal_iserror(page)) {
internal_close(fd);
return;
}
// Map the file into shadow of .rodata sections.
MemoryMappingLayout proc_maps(/*cache_enabled*/true);
uptr start, end, offset, prot;
// Reusing the buffer 'name'.
while (proc_maps.Next(&start, &end, &offset, name, ARRAY_SIZE(name), &prot)) {
if (name[0] != 0 && name[0] != '['
&& (prot & MemoryMappingLayout::kProtectionRead)
&& (prot & MemoryMappingLayout::kProtectionExecute)
&& !(prot & MemoryMappingLayout::kProtectionWrite)
&& IsAppMem(start)) {
// Assume it's .rodata
char *shadow_start = (char*)MemToShadow(start);
char *shadow_end = (char*)MemToShadow(end);
for (char *p = shadow_start; p < shadow_end; p += marker.size()) {
internal_mmap(p, Min<uptr>(marker.size(), shadow_end - p),
PROT_READ, MAP_PRIVATE | MAP_FIXED, fd, 0);
}
}
}
internal_close(fd);
}
void InitializeShadowMemoryPlatform() {
MapRodata();
}
static void InitDataSeg() {
MemoryMappingLayout proc_maps(true);
uptr start, end, offset;
char name[128];
#if SANITIZER_FREEBSD
// On FreeBSD BSS is usually the last block allocated within the
// low range and heap is the last block allocated within the range
// 0x800000000-0x8ffffffff.
while (proc_maps.Next(&start, &end, &offset, name, ARRAY_SIZE(name),
/*protection*/ 0)) {
DPrintf("%p-%p %p %s\n", start, end, offset, name);
if ((start & 0xffff00000000ULL) == 0 && (end & 0xffff00000000ULL) == 0 &&
name[0] == '\0') {
g_data_start = start;
g_data_end = end;
}
}
#else
bool prev_is_data = false;
while (proc_maps.Next(&start, &end, &offset, name, ARRAY_SIZE(name),
/*protection*/ 0)) {
DPrintf("%p-%p %p %s\n", start, end, offset, name);
bool is_data = offset != 0 && name[0] != 0;
// BSS may get merged with [heap] in /proc/self/maps. This is not very
// reliable.
bool is_bss = offset == 0 &&
(name[0] == 0 || internal_strcmp(name, "[heap]") == 0) && prev_is_data;
if (g_data_start == 0 && is_data)
g_data_start = start;
if (is_bss)
g_data_end = end;
prev_is_data = is_data;
}
#endif
DPrintf("guessed data_start=%p data_end=%p\n", g_data_start, g_data_end);
CHECK_LT(g_data_start, g_data_end);
CHECK_GE((uptr)&g_data_start, g_data_start);
CHECK_LT((uptr)&g_data_start, g_data_end);
}
#endif // #ifndef SANITIZER_GO
void InitializePlatform() {
DisableCoreDumperIfNecessary();
// Go maps shadow memory lazily and works fine with limited address space.
// Unlimited stack is not a problem as well, because the executable
// is not compiled with -pie.
if (kCppMode) {
bool reexec = false;
// TSan doesn't play well with unlimited stack size (as stack
// overlaps with shadow memory). If we detect unlimited stack size,
// we re-exec the program with limited stack size as a best effort.
if (StackSizeIsUnlimited()) {
const uptr kMaxStackSize = 32 * 1024 * 1024;
VReport(1, "Program is run with unlimited stack size, which wouldn't "
"work with ThreadSanitizer.\n"
"Re-execing with stack size limited to %zd bytes.\n",
kMaxStackSize);
SetStackSizeLimitInBytes(kMaxStackSize);
reexec = true;
}
if (!AddressSpaceIsUnlimited()) {
Report("WARNING: Program is run with limited virtual address space,"
" which wouldn't work with ThreadSanitizer.\n");
Report("Re-execing with unlimited virtual address space.\n");
SetAddressSpaceUnlimited();
reexec = true;
}
#if SANITIZER_LINUX && defined(__aarch64__)
// Initialize the guard pointer used in {sig}{set,long}jump.
InitializeGuardPtr();
#endif
if (reexec)
ReExec();
}
#ifndef SANITIZER_GO
CheckAndProtect();
InitTlsSize();
InitDataSeg();
#endif
}
bool IsGlobalVar(uptr addr) {
return g_data_start && addr >= g_data_start && addr < g_data_end;
}
#ifndef SANITIZER_GO
// Extract file descriptors passed to glibc internal __res_iclose function.
// This is required to properly "close" the fds, because we do not see internal
// closes within glibc. The code is a pure hack.
int ExtractResolvFDs(void *state, int *fds, int nfd) {
#if SANITIZER_LINUX
int cnt = 0;
__res_state *statp = (__res_state*)state;
for (int i = 0; i < MAXNS && cnt < nfd; i++) {
if (statp->_u._ext.nsaddrs[i] && statp->_u._ext.nssocks[i] != -1)
fds[cnt++] = statp->_u._ext.nssocks[i];
}
return cnt;
#else
return 0;
#endif
}
// Extract file descriptors passed via UNIX domain sockets.
// This is requried to properly handle "open" of these fds.
// see 'man recvmsg' and 'man 3 cmsg'.
int ExtractRecvmsgFDs(void *msgp, int *fds, int nfd) {
int res = 0;
msghdr *msg = (msghdr*)msgp;
struct cmsghdr *cmsg = CMSG_FIRSTHDR(msg);
for (; cmsg; cmsg = CMSG_NXTHDR(msg, cmsg)) {
if (cmsg->cmsg_level != SOL_SOCKET || cmsg->cmsg_type != SCM_RIGHTS)
continue;
int n = (cmsg->cmsg_len - CMSG_LEN(0)) / sizeof(fds[0]);
for (int i = 0; i < n; i++) {
fds[res++] = ((int*)CMSG_DATA(cmsg))[i];
if (res == nfd)
return res;
}
}
return res;
}
// Note: this function runs with async signals enabled,
// so it must not touch any tsan state.
int call_pthread_cancel_with_cleanup(int(*fn)(void *c, void *m,
void *abstime), void *c, void *m, void *abstime,
void(*cleanup)(void *arg), void *arg) {
// pthread_cleanup_push/pop are hardcore macros mess.
// We can't intercept nor call them w/o including pthread.h.
int res;
pthread_cleanup_push(cleanup, arg);
res = fn(c, m, abstime);
pthread_cleanup_pop(0);
return res;
}
#endif
#ifndef SANITIZER_GO
void ReplaceSystemMalloc() { }
#endif
} // namespace __tsan
#endif // SANITIZER_LINUX || SANITIZER_FREEBSD