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//===-- tsan_platform_linux.cpp -------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// This file is a part of ThreadSanitizer (TSan), a race detector.
//
// Linux- and BSD-specific code.
//===----------------------------------------------------------------------===//
#include "sanitizer_common/sanitizer_platform.h"
#if SANITIZER_LINUX || SANITIZER_FREEBSD || SANITIZER_NETBSD
#include "sanitizer_common/sanitizer_common.h"
#include "sanitizer_common/sanitizer_libc.h"
#include "sanitizer_common/sanitizer_linux.h"
#include "sanitizer_common/sanitizer_platform_limits_netbsd.h"
#include "sanitizer_common/sanitizer_platform_limits_posix.h"
#include "sanitizer_common/sanitizer_posix.h"
#include "sanitizer_common/sanitizer_procmaps.h"
#include "sanitizer_common/sanitizer_stackdepot.h"
#include "sanitizer_common/sanitizer_stoptheworld.h"
#include "tsan_flags.h"
#include "tsan_platform.h"
#include "tsan_rtl.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>
#if SANITIZER_LINUX
#include <sys/personality.h>
#include <setjmp.h>
#endif
#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 <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__) && !SANITIZER_GO
# define INIT_LONGJMP_XOR_KEY 1
#else
# define INIT_LONGJMP_XOR_KEY 0
#endif
#if INIT_LONGJMP_XOR_KEY
#include "interception/interception.h"
// Must be declared outside of other namespaces.
DECLARE_REAL(int, _setjmp, void *env)
#endif
namespace __tsan {
#if INIT_LONGJMP_XOR_KEY
static void InitializeLongjmpXorKey();
static uptr longjmp_xor_key;
#endif
#ifdef TSAN_RUNTIME_VMA
// Runtime detected VMA size.
uptr vmaSize;
#endif
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 >= ShadowBeg() && p < ShadowEnd())
mem[MemShadow] += rss;
else if (p >= MetaShadowBeg() && p < MetaShadowEnd())
mem[MemMeta] += rss;
#if !SANITIZER_GO
else if (p >= HeapMemBeg() && p < HeapMemEnd())
mem[MemHeap] += rss;
else if (p >= LoAppMemBeg() && p < LoAppMemEnd())
mem[file ? MemFile : MemMmap] += rss;
else if (p >= HiAppMemBeg() && p < HiAppMemEnd())
mem[file ? MemFile : MemMmap] += rss;
#else
else if (p >= AppMemBeg() && p < AppMemEnd())
mem[file ? MemFile : MemMmap] += rss;
#endif
else if (p >= TraceMemBeg() && p < TraceMemEnd())
mem[MemTrace] += rss;
else
mem[MemOther] += rss;
}
void WriteMemoryProfile(char *buf, uptr buf_size, uptr nthread, uptr nlive) {
uptr mem[MemCount];
internal_memset(mem, 0, sizeof(mem[0]) * 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) {
ReleaseMemoryPagesToOS(ShadowBeg(), ShadowEnd());
}
#endif
void FlushShadowMemory() {
#if SANITIZER_LINUX
StopTheWorld(FlushShadowMemoryCallback, 0);
#endif
}
#if !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);
InternalMmapVector<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() * sizeof(u64));
// 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);
// Reusing the buffer 'name'.
MemoryMappedSegment segment(name, ARRAY_SIZE(name));
while (proc_maps.Next(&segment)) {
if (segment.filename[0] != 0 && segment.filename[0] != '[' &&
segment.IsReadable() && segment.IsExecutable() &&
!segment.IsWritable() && IsAppMem(segment.start)) {
// Assume it's .rodata
char *shadow_start = (char *)MemToShadow(segment.start);
char *shadow_end = (char *)MemToShadow(segment.end);
for (char *p = shadow_start; p < shadow_end;
p += marker.size() * sizeof(u64)) {
internal_mmap(p, Min<uptr>(marker.size() * sizeof(u64), shadow_end - p),
PROT_READ, MAP_PRIVATE | MAP_FIXED, fd, 0);
}
}
}
internal_close(fd);
}
void InitializeShadowMemoryPlatform() {
MapRodata();
}
#endif // #if !SANITIZER_GO
void InitializePlatformEarly() {
#ifdef TSAN_RUNTIME_VMA
vmaSize =
(MostSignificantSetBitIndex(GET_CURRENT_FRAME()) + 1);
#if defined(__aarch64__)
# if !SANITIZER_GO
if (vmaSize != 39 && vmaSize != 42 && vmaSize != 48) {
Printf("FATAL: ThreadSanitizer: unsupported VMA range\n");
Printf("FATAL: Found %zd - Supported 39, 42 and 48\n", vmaSize);
Die();
}
#else
if (vmaSize != 48) {
Printf("FATAL: ThreadSanitizer: unsupported VMA range\n");
Printf("FATAL: Found %zd - Supported 48\n", vmaSize);
Die();
}
#endif
#elif defined(__powerpc64__)
# if !SANITIZER_GO
if (vmaSize != 44 && vmaSize != 46 && vmaSize != 47) {
Printf("FATAL: ThreadSanitizer: unsupported VMA range\n");
Printf("FATAL: Found %zd - Supported 44, 46, and 47\n", vmaSize);
Die();
}
# else
if (vmaSize != 46 && vmaSize != 47) {
Printf("FATAL: ThreadSanitizer: unsupported VMA range\n");
Printf("FATAL: Found %zd - Supported 46, and 47\n", vmaSize);
Die();
}
# endif
#endif
#endif
}
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 !SANITIZER_GO
{
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__)
// After patch "arm64: mm: support ARCH_MMAP_RND_BITS." is introduced in
// linux kernel, the random gap between stack and mapped area is increased
// from 128M to 36G on 39-bit aarch64. As it is almost impossible to cover
// this big range, we should disable randomized virtual space on aarch64.
int old_personality = personality(0xffffffff);
if (old_personality != -1 && (old_personality & ADDR_NO_RANDOMIZE) == 0) {
VReport(1, "WARNING: Program is run with randomized virtual address "
"space, which wouldn't work with ThreadSanitizer.\n"
"Re-execing with fixed virtual address space.\n");
CHECK_NE(personality(old_personality | ADDR_NO_RANDOMIZE), -1);
reexec = true;
}
// Initialize the xor key used in {sig}{set,long}jump.
InitializeLongjmpXorKey();
#endif
if (reexec)
ReExec();
}
CheckAndProtect();
InitTlsSize();
#endif // !SANITIZER_GO
}
#if !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 && !SANITIZER_ANDROID
int cnt = 0;
struct __res_state *statp = (struct __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;
}
// Reverse operation of libc stack pointer mangling
static uptr UnmangleLongJmpSp(uptr mangled_sp) {
#if defined(__x86_64__)
# if SANITIZER_LINUX
// Reverse of:
// xor %fs:0x30, %rsi
// rol $0x11, %rsi
uptr sp;
asm("ror $0x11, %0 \n"
"xor %%fs:0x30, %0 \n"
: "=r" (sp)
: "0" (mangled_sp));
return sp;
# else
return mangled_sp;
# endif
#elif defined(__aarch64__)
# if SANITIZER_LINUX
return mangled_sp ^ longjmp_xor_key;
# else
return mangled_sp;
# endif
#elif defined(__powerpc64__)
// Reverse of:
// ld r4, -28696(r13)
// xor r4, r3, r4
uptr xor_key;
asm("ld %0, -28696(%%r13)" : "=r" (xor_key));
return mangled_sp ^ xor_key;
#elif defined(__mips__)
return mangled_sp;
#else
#error "Unknown platform"
#endif
}
#if SANITIZER_NETBSD
# ifdef __x86_64__
# define LONG_JMP_SP_ENV_SLOT 6
# else
# error unsupported
# endif
#elif defined(__powerpc__)
# define LONG_JMP_SP_ENV_SLOT 0
#elif SANITIZER_FREEBSD
# define LONG_JMP_SP_ENV_SLOT 2
#elif SANITIZER_LINUX
# ifdef __aarch64__
# define LONG_JMP_SP_ENV_SLOT 13
# elif defined(__mips64)
# define LONG_JMP_SP_ENV_SLOT 1
# else
# define LONG_JMP_SP_ENV_SLOT 6
# endif
#endif
uptr ExtractLongJmpSp(uptr *env) {
uptr mangled_sp = env[LONG_JMP_SP_ENV_SLOT];
return UnmangleLongJmpSp(mangled_sp);
}
#if INIT_LONGJMP_XOR_KEY
// GLIBC mangles the function pointers in jmp_buf (used in {set,long}*jmp
// functions) by XORing them with a random key. For AArch64 it is a global
// variable rather than a TCB one (as for x86_64/powerpc). We obtain the key by
// issuing a setjmp and XORing the SP pointer values to derive the key.
static void InitializeLongjmpXorKey() {
// 1. Call REAL(setjmp), which stores the mangled SP in env.
jmp_buf env;
REAL(_setjmp)(env);
// 2. Retrieve vanilla/mangled SP.
uptr sp;
asm("mov %0, sp" : "=r" (sp));
uptr mangled_sp = ((uptr *)&env)[LONG_JMP_SP_ENV_SLOT];
// 3. xor SPs to obtain key.
longjmp_xor_key = mangled_sp ^ sp;
}
#endif
void ImitateTlsWrite(ThreadState *thr, uptr tls_addr, uptr tls_size) {
// Check that the thr object is in tls;
const uptr thr_beg = (uptr)thr;
const uptr thr_end = (uptr)thr + sizeof(*thr);
CHECK_GE(thr_beg, tls_addr);
CHECK_LE(thr_beg, tls_addr + tls_size);
CHECK_GE(thr_end, tls_addr);
CHECK_LE(thr_end, tls_addr + tls_size);
// Since the thr object is huge, skip it.
MemoryRangeImitateWrite(thr, /*pc=*/2, tls_addr, thr_beg - tls_addr);
MemoryRangeImitateWrite(thr, /*pc=*/2, thr_end,
tls_addr + tls_size - thr_end);
}
// 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 // !SANITIZER_GO
#if !SANITIZER_GO
void ReplaceSystemMalloc() { }
#endif
#if !SANITIZER_GO
#if SANITIZER_ANDROID
// On Android, one thread can call intercepted functions after
// DestroyThreadState(), so add a fake thread state for "dead" threads.
static ThreadState *dead_thread_state = nullptr;
ThreadState *cur_thread() {
ThreadState* thr = reinterpret_cast<ThreadState*>(*get_android_tls_ptr());
if (thr == nullptr) {
__sanitizer_sigset_t emptyset;
internal_sigfillset(&emptyset);
__sanitizer_sigset_t oldset;
CHECK_EQ(0, internal_sigprocmask(SIG_SETMASK, &emptyset, &oldset));
thr = reinterpret_cast<ThreadState*>(*get_android_tls_ptr());
if (thr == nullptr) {
thr = reinterpret_cast<ThreadState*>(MmapOrDie(sizeof(ThreadState),
"ThreadState"));
*get_android_tls_ptr() = reinterpret_cast<uptr>(thr);
if (dead_thread_state == nullptr) {
dead_thread_state = reinterpret_cast<ThreadState*>(
MmapOrDie(sizeof(ThreadState), "ThreadState"));
dead_thread_state->fast_state.SetIgnoreBit();
dead_thread_state->ignore_interceptors = 1;
dead_thread_state->is_dead = true;
*const_cast<int*>(&dead_thread_state->tid) = -1;
CHECK_EQ(0, internal_mprotect(dead_thread_state, sizeof(ThreadState),
PROT_READ));
}
}
CHECK_EQ(0, internal_sigprocmask(SIG_SETMASK, &oldset, nullptr));
}
return thr;
}
void set_cur_thread(ThreadState *thr) {
*get_android_tls_ptr() = reinterpret_cast<uptr>(thr);
}
void cur_thread_finalize() {
__sanitizer_sigset_t emptyset;
internal_sigfillset(&emptyset);
__sanitizer_sigset_t oldset;
CHECK_EQ(0, internal_sigprocmask(SIG_SETMASK, &emptyset, &oldset));
ThreadState* thr = reinterpret_cast<ThreadState*>(*get_android_tls_ptr());
if (thr != dead_thread_state) {
*get_android_tls_ptr() = reinterpret_cast<uptr>(dead_thread_state);
UnmapOrDie(thr, sizeof(ThreadState));
}
CHECK_EQ(0, internal_sigprocmask(SIG_SETMASK, &oldset, nullptr));
}
#endif // SANITIZER_ANDROID
#endif // if !SANITIZER_GO
} // namespace __tsan
#endif // SANITIZER_LINUX || SANITIZER_FREEBSD || SANITIZER_NETBSD