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llvm-project/compiler-rt/lib/msan/msan.cc

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//===-- msan.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 a part of MemorySanitizer.
//
// MemorySanitizer runtime.
//===----------------------------------------------------------------------===//
#include "msan.h"
#include "msan_chained_origin_depot.h"
#include "msan_origin.h"
#include "msan_thread.h"
#include "sanitizer_common/sanitizer_atomic.h"
#include "sanitizer_common/sanitizer_common.h"
#include "sanitizer_common/sanitizer_flags.h"
#include "sanitizer_common/sanitizer_flag_parser.h"
#include "sanitizer_common/sanitizer_libc.h"
#include "sanitizer_common/sanitizer_procmaps.h"
#include "sanitizer_common/sanitizer_stacktrace.h"
#include "sanitizer_common/sanitizer_symbolizer.h"
#include "sanitizer_common/sanitizer_stackdepot.h"
// ACHTUNG! No system header includes in this file.
using namespace __sanitizer;
// Globals.
static THREADLOCAL int msan_expect_umr = 0;
static THREADLOCAL int msan_expected_umr_found = 0;
// Function argument shadow. Each argument starts at the next available 8-byte
// aligned address.
SANITIZER_INTERFACE_ATTRIBUTE
THREADLOCAL u64 __msan_param_tls[kMsanParamTlsSize / sizeof(u64)];
// Function argument origin. Each argument starts at the same offset as the
// corresponding shadow in (__msan_param_tls). Slightly weird, but changing this
// would break compatibility with older prebuilt binaries.
SANITIZER_INTERFACE_ATTRIBUTE
THREADLOCAL u32 __msan_param_origin_tls[kMsanParamTlsSize / sizeof(u32)];
SANITIZER_INTERFACE_ATTRIBUTE
THREADLOCAL u64 __msan_retval_tls[kMsanRetvalTlsSize / sizeof(u64)];
SANITIZER_INTERFACE_ATTRIBUTE
THREADLOCAL u32 __msan_retval_origin_tls;
SANITIZER_INTERFACE_ATTRIBUTE
THREADLOCAL u64 __msan_va_arg_tls[kMsanParamTlsSize / sizeof(u64)];
SANITIZER_INTERFACE_ATTRIBUTE
THREADLOCAL u64 __msan_va_arg_overflow_size_tls;
SANITIZER_INTERFACE_ATTRIBUTE
THREADLOCAL u32 __msan_origin_tls;
static THREADLOCAL int is_in_symbolizer;
extern "C" SANITIZER_WEAK_ATTRIBUTE const int __msan_track_origins;
int __msan_get_track_origins() {
return &__msan_track_origins ? __msan_track_origins : 0;
}
extern "C" SANITIZER_WEAK_ATTRIBUTE const int __msan_keep_going;
namespace __msan {
void EnterSymbolizer() { ++is_in_symbolizer; }
void ExitSymbolizer() { --is_in_symbolizer; }
bool IsInSymbolizer() { return is_in_symbolizer; }
static Flags msan_flags;
Flags *flags() {
return &msan_flags;
}
int msan_inited = 0;
bool msan_init_is_running;
int msan_report_count = 0;
void (*death_callback)(void);
// Array of stack origins.
// FIXME: make it resizable.
static const uptr kNumStackOriginDescrs = 1024 * 1024;
static const char *StackOriginDescr[kNumStackOriginDescrs];
static uptr StackOriginPC[kNumStackOriginDescrs];
static atomic_uint32_t NumStackOriginDescrs;
void Flags::SetDefaults() {
#define MSAN_FLAG(Type, Name, DefaultValue, Description) Name = DefaultValue;
#include "msan_flags.inc"
#undef MSAN_FLAG
}
// keep_going is an old name for halt_on_error,
// and it has inverse meaning.
class FlagHandlerKeepGoing : public FlagHandlerBase {
bool *halt_on_error_;
public:
explicit FlagHandlerKeepGoing(bool *halt_on_error)
: halt_on_error_(halt_on_error) {}
bool Parse(const char *value) {
bool tmp;
FlagHandler<bool> h(&tmp);
if (!h.Parse(value)) return false;
*halt_on_error_ = !tmp;
return true;
}
};
void RegisterMsanFlags(FlagParser *parser, Flags *f) {
#define MSAN_FLAG(Type, Name, DefaultValue, Description) \
RegisterFlag(parser, #Name, Description, &f->Name);
#include "msan_flags.inc"
#undef MSAN_FLAG
FlagHandlerKeepGoing *fh_keep_going =
new (INTERNAL_ALLOC) FlagHandlerKeepGoing(&f->halt_on_error); // NOLINT
parser->RegisterHandler("keep_going", fh_keep_going,
"deprecated, use halt_on_error");
}
static void InitializeFlags(Flags *f, const char *options) {
FlagParser parser;
RegisterMsanFlags(&parser, f);
RegisterCommonFlags(&parser);
SetCommonFlagsDefaults();
{
CommonFlags cf;
cf.CopyFrom(*common_flags());
cf.external_symbolizer_path = GetEnv("MSAN_SYMBOLIZER_PATH");
cf.malloc_context_size = 20;
cf.handle_ioctl = true;
// FIXME: test and enable.
cf.check_printf = false;
cf.intercept_tls_get_addr = true;
OverrideCommonFlags(cf);
}
f->SetDefaults();
// Override from user-specified string.
if (__msan_default_options)
parser.ParseString(__msan_default_options());
parser.ParseString(options);
if (common_flags()->help) parser.PrintFlagDescriptions();
// Check flag values:
if (f->exit_code < 0 || f->exit_code > 127) {
Printf("Exit code not in [0, 128) range: %d\n", f->exit_code);
Die();
}
if (f->origin_history_size < 0 ||
f->origin_history_size > Origin::kMaxDepth) {
Printf(
"Origin history size invalid: %d. Must be 0 (unlimited) or in [1, %d] "
"range.\n",
f->origin_history_size, Origin::kMaxDepth);
Die();
}
// Limiting to kStackDepotMaxUseCount / 2 to avoid overflow in
// StackDepotHandle::inc_use_count_unsafe.
if (f->origin_history_per_stack_limit < 0 ||
f->origin_history_per_stack_limit > kStackDepotMaxUseCount / 2) {
Printf(
"Origin per-stack limit invalid: %d. Must be 0 (unlimited) or in [1, "
"%d] range.\n",
f->origin_history_per_stack_limit, kStackDepotMaxUseCount / 2);
Die();
}
if (f->store_context_size < 1) f->store_context_size = 1;
}
void GetStackTrace(BufferedStackTrace *stack, uptr max_s, uptr pc, uptr bp,
bool request_fast_unwind) {
MsanThread *t = GetCurrentThread();
if (!t || !StackTrace::WillUseFastUnwind(request_fast_unwind)) {
// Block reports from our interceptors during _Unwind_Backtrace.
SymbolizerScope sym_scope;
return stack->Unwind(max_s, pc, bp, 0, 0, 0, request_fast_unwind);
}
stack->Unwind(max_s, pc, bp, 0, t->stack_top(), t->stack_bottom(),
request_fast_unwind);
}
void PrintWarning(uptr pc, uptr bp) {
PrintWarningWithOrigin(pc, bp, __msan_origin_tls);
}
void PrintWarningWithOrigin(uptr pc, uptr bp, u32 origin) {
if (msan_expect_umr) {
// Printf("Expected UMR\n");
__msan_origin_tls = origin;
msan_expected_umr_found = 1;
return;
}
++msan_report_count;
GET_FATAL_STACK_TRACE_PC_BP(pc, bp);
u32 report_origin =
(__msan_get_track_origins() && Origin::isValidId(origin)) ? origin : 0;
ReportUMR(&stack, report_origin);
if (__msan_get_track_origins() && !Origin::isValidId(origin)) {
Printf(
" ORIGIN: invalid (%x). Might be a bug in MemorySanitizer origin "
"tracking.\n This could still be a bug in your code, too!\n",
origin);
}
}
void UnpoisonParam(uptr n) {
internal_memset(__msan_param_tls, 0, n * sizeof(*__msan_param_tls));
}
// Backup MSan runtime TLS state.
// Implementation must be async-signal-safe.
// Instances of this class may live on the signal handler stack, and data size
// may be an issue.
void ScopedThreadLocalStateBackup::Backup() {
va_arg_overflow_size_tls = __msan_va_arg_overflow_size_tls;
}
void ScopedThreadLocalStateBackup::Restore() {
// A lame implementation that only keeps essential state and resets the rest.
__msan_va_arg_overflow_size_tls = va_arg_overflow_size_tls;
internal_memset(__msan_param_tls, 0, sizeof(__msan_param_tls));
internal_memset(__msan_retval_tls, 0, sizeof(__msan_retval_tls));
internal_memset(__msan_va_arg_tls, 0, sizeof(__msan_va_arg_tls));
if (__msan_get_track_origins()) {
internal_memset(&__msan_retval_origin_tls, 0,
sizeof(__msan_retval_origin_tls));
internal_memset(__msan_param_origin_tls, 0,
sizeof(__msan_param_origin_tls));
}
}
void UnpoisonThreadLocalState() {
}
const char *GetStackOriginDescr(u32 id, uptr *pc) {
CHECK_LT(id, kNumStackOriginDescrs);
if (pc) *pc = StackOriginPC[id];
return StackOriginDescr[id];
}
u32 ChainOrigin(u32 id, StackTrace *stack) {
MsanThread *t = GetCurrentThread();
if (t && t->InSignalHandler())
return id;
Origin o = Origin::FromRawId(id);
Origin chained = Origin::CreateChainedOrigin(o, stack);
return chained.raw_id();
}
} // namespace __msan
// Interface.
using namespace __msan;
#define MSAN_MAYBE_WARNING(type, size) \
void __msan_maybe_warning_##size(type s, u32 o) { \
GET_CALLER_PC_BP_SP; \
(void) sp; \
if (UNLIKELY(s)) { \
PrintWarningWithOrigin(pc, bp, o); \
if (__msan::flags()->halt_on_error) { \
Printf("Exiting\n"); \
Die(); \
} \
} \
}
MSAN_MAYBE_WARNING(u8, 1)
MSAN_MAYBE_WARNING(u16, 2)
MSAN_MAYBE_WARNING(u32, 4)
MSAN_MAYBE_WARNING(u64, 8)
#define MSAN_MAYBE_STORE_ORIGIN(type, size) \
void __msan_maybe_store_origin_##size(type s, void *p, u32 o) { \
if (UNLIKELY(s)) { \
if (__msan_get_track_origins() > 1) { \
GET_CALLER_PC_BP_SP; \
(void) sp; \
GET_STORE_STACK_TRACE_PC_BP(pc, bp); \
o = ChainOrigin(o, &stack); \
} \
*(u32 *)MEM_TO_ORIGIN((uptr)p & ~3UL) = o; \
} \
}
MSAN_MAYBE_STORE_ORIGIN(u8, 1)
MSAN_MAYBE_STORE_ORIGIN(u16, 2)
MSAN_MAYBE_STORE_ORIGIN(u32, 4)
MSAN_MAYBE_STORE_ORIGIN(u64, 8)
void __msan_warning() {
GET_CALLER_PC_BP_SP;
(void)sp;
PrintWarning(pc, bp);
if (__msan::flags()->halt_on_error) {
if (__msan::flags()->print_stats)
ReportStats();
Printf("Exiting\n");
Die();
}
}
void __msan_warning_noreturn() {
GET_CALLER_PC_BP_SP;
(void)sp;
PrintWarning(pc, bp);
if (__msan::flags()->print_stats)
ReportStats();
Printf("Exiting\n");
Die();
}
void __msan_init() {
CHECK(!msan_init_is_running);
if (msan_inited) return;
msan_init_is_running = 1;
SanitizerToolName = "MemorySanitizer";
SetDieCallback(MsanDie);
InitTlsSize();
const char *msan_options = GetEnv("MSAN_OPTIONS");
InitializeFlags(&msan_flags, msan_options);
__sanitizer_set_report_path(common_flags()->log_path);
InitializeInterceptors();
InstallAtExitHandler(); // Needs __cxa_atexit interceptor.
if (MSAN_REPLACE_OPERATORS_NEW_AND_DELETE)
ReplaceOperatorsNewAndDelete();
DisableCoreDumperIfNecessary();
if (StackSizeIsUnlimited()) {
VPrintf(1, "Unlimited stack, doing reexec\n");
// A reasonably large stack size. It is bigger than the usual 8Mb, because,
// well, the program could have been run with unlimited stack for a reason.
SetStackSizeLimitInBytes(32 * 1024 * 1024);
ReExec();
}
VPrintf(1, "MSAN_OPTIONS: %s\n", msan_options ? msan_options : "<empty>");
__msan_clear_on_return();
if (__msan_get_track_origins())
VPrintf(1, "msan_track_origins\n");
if (!InitShadow(/* map_shadow */ true, __msan_get_track_origins())) {
Printf("FATAL: MemorySanitizer can not mmap the shadow memory.\n");
Printf("FATAL: Make sure to compile with -fPIE and to link with -pie.\n");
Printf("FATAL: Disabling ASLR is known to cause this error.\n");
Printf("FATAL: If running under GDB, try "
"'set disable-randomization off'.\n");
DumpProcessMap();
Die();
}
Symbolizer::GetOrInit()->AddHooks(EnterSymbolizer, ExitSymbolizer);
InitializeCoverage(common_flags()->coverage, common_flags()->coverage_dir);
MsanTSDInit(MsanTSDDtor);
MsanThread *main_thread = MsanThread::Create(0, 0);
SetCurrentThread(main_thread);
main_thread->ThreadStart();
VPrintf(1, "MemorySanitizer init done\n");
msan_init_is_running = 0;
msan_inited = 1;
}
void __msan_set_exit_code(int exit_code) {
flags()->exit_code = exit_code;
}
void __msan_set_keep_going(int keep_going) {
flags()->halt_on_error = !keep_going;
}
void __msan_set_expect_umr(int expect_umr) {
if (expect_umr) {
msan_expected_umr_found = 0;
} else if (!msan_expected_umr_found) {
GET_CALLER_PC_BP_SP;
(void)sp;
GET_FATAL_STACK_TRACE_PC_BP(pc, bp);
ReportExpectedUMRNotFound(&stack);
Die();
}
msan_expect_umr = expect_umr;
}
void __msan_print_shadow(const void *x, uptr size) {
if (!MEM_IS_APP(x)) {
Printf("Not a valid application address: %p\n", x);
return;
}
DescribeMemoryRange(x, size);
}
void __msan_dump_shadow(const void *x, uptr size) {
if (!MEM_IS_APP(x)) {
Printf("Not a valid application address: %p\n", x);
return;
}
unsigned char *s = (unsigned char*)MEM_TO_SHADOW(x);
for (uptr i = 0; i < size; i++) {
#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__
Printf("%x%x ", s[i] & 0xf, s[i] >> 4);
#else
Printf("%x%x ", s[i] >> 4, s[i] & 0xf);
#endif
}
Printf("\n");
}
sptr __msan_test_shadow(const void *x, uptr size) {
if (!MEM_IS_APP(x)) return -1;
unsigned char *s = (unsigned char *)MEM_TO_SHADOW((uptr)x);
for (uptr i = 0; i < size; ++i)
if (s[i])
return i;
return -1;
}
void __msan_check_mem_is_initialized(const void *x, uptr size) {
if (!__msan::flags()->report_umrs) return;
sptr offset = __msan_test_shadow(x, size);
if (offset < 0)
return;
GET_CALLER_PC_BP_SP;
(void)sp;
ReportUMRInsideAddressRange(__func__, x, size, offset);
__msan::PrintWarningWithOrigin(pc, bp,
__msan_get_origin(((const char *)x) + offset));
if (__msan::flags()->halt_on_error) {
Printf("Exiting\n");
Die();
}
}
int __msan_set_poison_in_malloc(int do_poison) {
int old = flags()->poison_in_malloc;
flags()->poison_in_malloc = do_poison;
return old;
}
int __msan_has_dynamic_component() { return false; }
NOINLINE
void __msan_clear_on_return() {
__msan_param_tls[0] = 0;
}
void __msan_partial_poison(const void* data, void* shadow, uptr size) {
internal_memcpy((void*)MEM_TO_SHADOW((uptr)data), shadow, size);
}
void __msan_load_unpoisoned(void *src, uptr size, void *dst) {
internal_memcpy(dst, src, size);
__msan_unpoison(dst, size);
}
void __msan_set_origin(const void *a, uptr size, u32 origin) {
// Origin mapping is 4 bytes per 4 bytes of application memory.
// Here we extend the range such that its left and right bounds are both
// 4 byte aligned.
if (!__msan_get_track_origins()) return;
uptr x = MEM_TO_ORIGIN((uptr)a);
uptr beg = x & ~3UL; // align down.
uptr end = (x + size + 3) & ~3UL; // align up.
u64 origin64 = ((u64)origin << 32) | origin;
// This is like memset, but the value is 32-bit. We unroll by 2 to write
// 64 bits at once. May want to unroll further to get 128-bit stores.
if (beg & 7ULL) {
*(u32*)beg = origin;
beg += 4;
}
for (uptr addr = beg; addr < (end & ~7UL); addr += 8)
*(u64*)addr = origin64;
if (end & 7ULL)
*(u32*)(end - 4) = origin;
}
// 'descr' is created at compile time and contains '----' in the beginning.
// When we see descr for the first time we replace '----' with a uniq id
// and set the origin to (id | (31-th bit)).
void __msan_set_alloca_origin(void *a, uptr size, char *descr) {
__msan_set_alloca_origin4(a, size, descr, 0);
}
void __msan_set_alloca_origin4(void *a, uptr size, char *descr, uptr pc) {
static const u32 dash = '-';
static const u32 first_timer =
dash + (dash << 8) + (dash << 16) + (dash << 24);
u32 *id_ptr = (u32*)descr;
bool print = false; // internal_strstr(descr + 4, "AllocaTOTest") != 0;
u32 id = *id_ptr;
if (id == first_timer) {
u32 idx = atomic_fetch_add(&NumStackOriginDescrs, 1, memory_order_relaxed);
CHECK_LT(idx, kNumStackOriginDescrs);
StackOriginDescr[idx] = descr + 4;
StackOriginPC[idx] = pc;
id = Origin::CreateStackOrigin(idx).raw_id();
*id_ptr = id;
if (print)
Printf("First time: idx=%d id=%d %s %p \n", idx, id, descr + 4, pc);
}
if (print)
Printf("__msan_set_alloca_origin: descr=%s id=%x\n", descr + 4, id);
__msan_set_origin(a, size, id);
}
u32 __msan_chain_origin(u32 id) {
GET_CALLER_PC_BP_SP;
(void)sp;
GET_STORE_STACK_TRACE_PC_BP(pc, bp);
return ChainOrigin(id, &stack);
}
u32 __msan_get_origin(const void *a) {
if (!__msan_get_track_origins()) return 0;
uptr x = (uptr)a;
uptr aligned = x & ~3ULL;
uptr origin_ptr = MEM_TO_ORIGIN(aligned);
return *(u32*)origin_ptr;
}
u32 __msan_get_umr_origin() {
return __msan_origin_tls;
}
u16 __sanitizer_unaligned_load16(const uu16 *p) {
__msan_retval_tls[0] = *(uu16 *)MEM_TO_SHADOW((uptr)p);
if (__msan_get_track_origins())
__msan_retval_origin_tls = GetOriginIfPoisoned((uptr)p, sizeof(*p));
return *p;
}
u32 __sanitizer_unaligned_load32(const uu32 *p) {
__msan_retval_tls[0] = *(uu32 *)MEM_TO_SHADOW((uptr)p);
if (__msan_get_track_origins())
__msan_retval_origin_tls = GetOriginIfPoisoned((uptr)p, sizeof(*p));
return *p;
}
u64 __sanitizer_unaligned_load64(const uu64 *p) {
__msan_retval_tls[0] = *(uu64 *)MEM_TO_SHADOW((uptr)p);
if (__msan_get_track_origins())
__msan_retval_origin_tls = GetOriginIfPoisoned((uptr)p, sizeof(*p));
return *p;
}
void __sanitizer_unaligned_store16(uu16 *p, u16 x) {
u16 s = __msan_param_tls[1];
*(uu16 *)MEM_TO_SHADOW((uptr)p) = s;
if (s && __msan_get_track_origins())
if (uu32 o = __msan_param_origin_tls[2])
SetOriginIfPoisoned((uptr)p, (uptr)&s, sizeof(s), o);
*p = x;
}
void __sanitizer_unaligned_store32(uu32 *p, u32 x) {
u32 s = __msan_param_tls[1];
*(uu32 *)MEM_TO_SHADOW((uptr)p) = s;
if (s && __msan_get_track_origins())
if (uu32 o = __msan_param_origin_tls[2])
SetOriginIfPoisoned((uptr)p, (uptr)&s, sizeof(s), o);
*p = x;
}
void __sanitizer_unaligned_store64(uu64 *p, u64 x) {
u64 s = __msan_param_tls[1];
*(uu64 *)MEM_TO_SHADOW((uptr)p) = s;
if (s && __msan_get_track_origins())
if (uu32 o = __msan_param_origin_tls[2])
SetOriginIfPoisoned((uptr)p, (uptr)&s, sizeof(s), o);
*p = x;
}
void __msan_set_death_callback(void (*callback)(void)) {
death_callback = callback;
}
#if !SANITIZER_SUPPORTS_WEAK_HOOKS
extern "C" {
SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE
const char* __msan_default_options() { return ""; }
} // extern "C"
#endif
extern "C" {
SANITIZER_INTERFACE_ATTRIBUTE
void __sanitizer_print_stack_trace() {
GET_FATAL_STACK_TRACE_PC_BP(StackTrace::GetCurrentPc(), GET_CURRENT_FRAME());
stack.Print();
}
} // extern "C"
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