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//===-- hwasan.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 HWAddressSanitizer.
//
// HWAddressSanitizer runtime.
//===----------------------------------------------------------------------===//
#include "hwasan.h"
#include "hwasan_checks.h"
#include "hwasan_dynamic_shadow.h"
#include "hwasan_globals.h"
#include "hwasan_mapping.h"
#include "hwasan_poisoning.h"
#include "hwasan_report.h"
#include "hwasan_thread.h"
#include "hwasan_thread_list.h"
#include "sanitizer_common/sanitizer_atomic.h"
#include "sanitizer_common/sanitizer_common.h"
#include "sanitizer_common/sanitizer_flag_parser.h"
#include "sanitizer_common/sanitizer_flags.h"
#include "sanitizer_common/sanitizer_libc.h"
#include "sanitizer_common/sanitizer_procmaps.h"
#include "sanitizer_common/sanitizer_stackdepot.h"
#include "sanitizer_common/sanitizer_stacktrace.h"
#include "sanitizer_common/sanitizer_symbolizer.h"
#include "ubsan/ubsan_flags.h"
#include "ubsan/ubsan_init.h"
// ACHTUNG! No system header includes in this file.
using namespace __sanitizer;
namespace __hwasan {
static Flags hwasan_flags;
Flags *flags() {
return &hwasan_flags;
}
int hwasan_inited = 0;
int hwasan_instrumentation_inited = 0;
bool hwasan_init_is_running;
int hwasan_report_count = 0;
uptr kLowShadowStart;
uptr kLowShadowEnd;
uptr kHighShadowStart;
uptr kHighShadowEnd;
void Flags::SetDefaults() {
#define HWASAN_FLAG(Type, Name, DefaultValue, Description) Name = DefaultValue;
#include "hwasan_flags.inc"
#undef HWASAN_FLAG
}
static void RegisterHwasanFlags(FlagParser *parser, Flags *f) {
#define HWASAN_FLAG(Type, Name, DefaultValue, Description) \
RegisterFlag(parser, #Name, Description, &f->Name);
#include "hwasan_flags.inc"
#undef HWASAN_FLAG
}
static void InitializeFlags() {
SetCommonFlagsDefaults();
{
CommonFlags cf;
cf.CopyFrom(*common_flags());
cf.external_symbolizer_path = GetEnv("HWASAN_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;
cf.exitcode = 99;
// 8 shadow pages ~512kB, small enough to cover common stack sizes.
cf.clear_shadow_mmap_threshold = 4096 * (SANITIZER_ANDROID ? 2 : 8);
// Sigtrap is used in error reporting.
cf.handle_sigtrap = kHandleSignalExclusive;
#if SANITIZER_ANDROID
// Let platform handle other signals. It is better at reporting them then we
// are.
cf.handle_segv = kHandleSignalNo;
cf.handle_sigbus = kHandleSignalNo;
cf.handle_abort = kHandleSignalNo;
cf.handle_sigill = kHandleSignalNo;
cf.handle_sigfpe = kHandleSignalNo;
#endif
OverrideCommonFlags(cf);
}
Flags *f = flags();
f->SetDefaults();
FlagParser parser;
RegisterHwasanFlags(&parser, f);
RegisterCommonFlags(&parser);
#if HWASAN_CONTAINS_UBSAN
__ubsan::Flags *uf = __ubsan::flags();
uf->SetDefaults();
FlagParser ubsan_parser;
__ubsan::RegisterUbsanFlags(&ubsan_parser, uf);
RegisterCommonFlags(&ubsan_parser);
#endif
// Override from user-specified string.
if (__hwasan_default_options)
parser.ParseString(__hwasan_default_options());
#if HWASAN_CONTAINS_UBSAN
const char *ubsan_default_options = __ubsan_default_options();
ubsan_parser.ParseString(ubsan_default_options);
#endif
parser.ParseStringFromEnv("HWASAN_OPTIONS");
#if HWASAN_CONTAINS_UBSAN
ubsan_parser.ParseStringFromEnv("UBSAN_OPTIONS");
#endif
InitializeCommonFlags();
if (Verbosity()) ReportUnrecognizedFlags();
if (common_flags()->help) parser.PrintFlagDescriptions();
}
static void CheckUnwind() {
GET_FATAL_STACK_TRACE_PC_BP(StackTrace::GetCurrentPc(), GET_CURRENT_FRAME());
stack.Print();
}
static void HwasanFormatMemoryUsage(InternalScopedString &s) {
HwasanThreadList &thread_list = hwasanThreadList();
auto thread_stats = thread_list.GetThreadStats();
auto sds = StackDepotGetStats();
AllocatorStatCounters asc;
GetAllocatorStats(asc);
s.append(
"HWASAN pid: %d rss: %zd threads: %zd stacks: %zd"
" thr_aux: %zd stack_depot: %zd uniq_stacks: %zd"
" heap: %zd",
internal_getpid(), GetRSS(), thread_stats.n_live_threads,
thread_stats.total_stack_size,
thread_stats.n_live_threads * thread_list.MemoryUsedPerThread(),
sds.allocated, sds.n_uniq_ids, asc[AllocatorStatMapped]);
}
#if SANITIZER_ANDROID
static constexpr uptr kMemoryUsageBufferSize = 4096;
static char *memory_usage_buffer = nullptr;
static void InitMemoryUsage() {
memory_usage_buffer =
(char *)MmapOrDie(kMemoryUsageBufferSize, "memory usage string");
CHECK(memory_usage_buffer);
memory_usage_buffer[0] = '\0';
DecorateMapping((uptr)memory_usage_buffer, kMemoryUsageBufferSize,
memory_usage_buffer);
}
void UpdateMemoryUsage() {
if (!flags()->export_memory_stats)
return;
if (!memory_usage_buffer)
InitMemoryUsage();
InternalScopedString s;
HwasanFormatMemoryUsage(s);
internal_strncpy(memory_usage_buffer, s.data(), kMemoryUsageBufferSize - 1);
memory_usage_buffer[kMemoryUsageBufferSize - 1] = '\0';
}
#else
void UpdateMemoryUsage() {}
#endif
void HwasanAtExit() {
if (common_flags()->print_module_map)
DumpProcessMap();
if (flags()->print_stats && (flags()->atexit || hwasan_report_count > 0))
ReportStats();
if (hwasan_report_count > 0) {
// ReportAtExitStatistics();
if (common_flags()->exitcode)
internal__exit(common_flags()->exitcode);
}
}
void HandleTagMismatch(AccessInfo ai, uptr pc, uptr frame, void *uc,
uptr *registers_frame) {
InternalMmapVector<BufferedStackTrace> stack_buffer(1);
BufferedStackTrace *stack = stack_buffer.data();
stack->Reset();
stack->Unwind(pc, frame, uc, common_flags()->fast_unwind_on_fatal);
// The second stack frame contains the failure __hwasan_check function, as
// we have a stack frame for the registers saved in __hwasan_tag_mismatch that
// we wish to ignore. This (currently) only occurs on AArch64, as x64
// implementations use SIGTRAP to implement the failure, and thus do not go
// through the stack saver.
if (registers_frame && stack->trace && stack->size > 0) {
stack->trace++;
stack->size--;
}
bool fatal = flags()->halt_on_error || !ai.recover;
ReportTagMismatch(stack, ai.addr, ai.size, ai.is_store, fatal,
registers_frame);
}
void HwasanTagMismatch(uptr addr, uptr access_info, uptr *registers_frame,
size_t outsize) {
__hwasan::AccessInfo ai;
ai.is_store = access_info & 0x10;
ai.is_load = !ai.is_store;
ai.recover = access_info & 0x20;
ai.addr = addr;
if ((access_info & 0xf) == 0xf)
ai.size = outsize;
else
ai.size = 1 << (access_info & 0xf);
HandleTagMismatch(ai, (uptr)__builtin_return_address(0),
(uptr)__builtin_frame_address(0), nullptr, registers_frame);
__builtin_unreachable();
}
Thread *GetCurrentThread() {
uptr *ThreadLongPtr = GetCurrentThreadLongPtr();
if (UNLIKELY(*ThreadLongPtr == 0))
return nullptr;
auto *R = (StackAllocationsRingBuffer *)ThreadLongPtr;
return hwasanThreadList().GetThreadByBufferAddress((uptr)R->Next());
}
} // namespace __hwasan
using namespace __hwasan;
void __sanitizer::BufferedStackTrace::UnwindImpl(
uptr pc, uptr bp, void *context, bool request_fast, u32 max_depth) {
Thread *t = GetCurrentThread();
if (!t) {
// The thread is still being created, or has already been destroyed.
size = 0;
return;
}
Unwind(max_depth, pc, bp, context, t->stack_top(), t->stack_bottom(),
request_fast);
}
static bool InitializeSingleGlobal(const hwasan_global &global) {
uptr full_granule_size = RoundDownTo(global.size(), 16);
TagMemoryAligned(global.addr(), full_granule_size, global.tag());
if (global.size() % 16)
TagMemoryAligned(global.addr() + full_granule_size, 16, global.size() % 16);
return false;
}
static void InitLoadedGlobals() {
dl_iterate_phdr(
[](dl_phdr_info *info, size_t /* size */, void * /* data */) -> int {
for (const hwasan_global &global : HwasanGlobalsFor(
info->dlpi_addr, info->dlpi_phdr, info->dlpi_phnum))
InitializeSingleGlobal(global);
return 0;
},
nullptr);
}
// Prepare to run instrumented code on the main thread.
static void InitInstrumentation() {
if (hwasan_instrumentation_inited) return;
InitializeOsSupport();
if (!InitShadow()) {
Printf("FATAL: HWAddressSanitizer cannot mmap the shadow memory.\n");
DumpProcessMap();
Die();
}
InitThreads();
hwasan_instrumentation_inited = 1;
}
// Interface.
uptr __hwasan_shadow_memory_dynamic_address; // Global interface symbol.
// This function was used by the old frame descriptor mechanism. We keep it
// around to avoid breaking ABI.
void __hwasan_init_frames(uptr beg, uptr end) {}
void __hwasan_init_static() {
InitShadowGOT();
InitInstrumentation();
// In the non-static code path we call dl_iterate_phdr here. But at this point
// libc might not have been initialized enough for dl_iterate_phdr to work.
// Fortunately, since this is a statically linked executable we can use the
// linker-defined symbol __ehdr_start to find the only relevant set of phdrs.
extern ElfW(Ehdr) __ehdr_start;
for (const hwasan_global &global : HwasanGlobalsFor(
/* base */ 0,
reinterpret_cast<const ElfW(Phdr) *>(
reinterpret_cast<const char *>(&__ehdr_start) +
__ehdr_start.e_phoff),
__ehdr_start.e_phnum))
InitializeSingleGlobal(global);
}
__attribute__((constructor(0))) void __hwasan_init() {
CHECK(!hwasan_init_is_running);
if (hwasan_inited) return;
hwasan_init_is_running = 1;
SanitizerToolName = "HWAddressSanitizer";
InitTlsSize();
CacheBinaryName();
InitializeFlags();
// Install tool-specific callbacks in sanitizer_common.
SetCheckUnwindCallback(CheckUnwind);
__sanitizer_set_report_path(common_flags()->log_path);
AndroidTestTlsSlot();
DisableCoreDumperIfNecessary();
InitInstrumentation();
InitLoadedGlobals();
// Needs to be called here because flags()->random_tags might not have been
// initialized when InitInstrumentation() was called.
GetCurrentThread()->EnsureRandomStateInited();
SetPrintfAndReportCallback(AppendToErrorMessageBuffer);
// This may call libc -> needs initialized shadow.
AndroidLogInit();
InitializeInterceptors();
InstallDeadlySignalHandlers(HwasanOnDeadlySignal);
InstallAtExitHandler(); // Needs __cxa_atexit interceptor.
InitializeCoverage(common_flags()->coverage, common_flags()->coverage_dir);
HwasanTSDInit();
HwasanTSDThreadInit();
HwasanAllocatorInit();
HwasanInstallAtForkHandler();
#if HWASAN_CONTAINS_UBSAN
__ubsan::InitAsPlugin();
#endif
VPrintf(1, "HWAddressSanitizer init done\n");
hwasan_init_is_running = 0;
hwasan_inited = 1;
}
void __hwasan_library_loaded(ElfW(Addr) base, const ElfW(Phdr) * phdr,
ElfW(Half) phnum) {
for (const hwasan_global &global : HwasanGlobalsFor(base, phdr, phnum))
InitializeSingleGlobal(global);
}
void __hwasan_library_unloaded(ElfW(Addr) base, const ElfW(Phdr) * phdr,
ElfW(Half) phnum) {
for (; phnum != 0; ++phdr, --phnum)
if (phdr->p_type == PT_LOAD)
TagMemory(base + phdr->p_vaddr, phdr->p_memsz, 0);
}
void __hwasan_print_shadow(const void *p, uptr sz) {
uptr ptr_raw = UntagAddr(reinterpret_cast<uptr>(p));
uptr shadow_first = MemToShadow(ptr_raw);
uptr shadow_last = MemToShadow(ptr_raw + sz - 1);
Printf("HWASan shadow map for %zx .. %zx (pointer tag %x)\n", ptr_raw,
ptr_raw + sz, GetTagFromPointer((uptr)p));
for (uptr s = shadow_first; s <= shadow_last; ++s) {
tag_t mem_tag = *reinterpret_cast<tag_t *>(s);
uptr granule_addr = ShadowToMem(s);
if (mem_tag && mem_tag < kShadowAlignment)
Printf(" %zx: %02x(%02x)\n", granule_addr, mem_tag,
*reinterpret_cast<tag_t *>(granule_addr + kShadowAlignment - 1));
else
Printf(" %zx: %02x\n", granule_addr, mem_tag);
}
}
sptr __hwasan_test_shadow(const void *p, uptr sz) {
if (sz == 0)
return -1;
tag_t ptr_tag = GetTagFromPointer((uptr)p);
uptr ptr_raw = UntagAddr(reinterpret_cast<uptr>(p));
uptr shadow_first = MemToShadow(ptr_raw);
uptr shadow_last = MemToShadow(ptr_raw + sz - 1);
for (uptr s = shadow_first; s <= shadow_last; ++s)
if (*(tag_t *)s != ptr_tag) {
sptr offset = ShadowToMem(s) - ptr_raw;
return offset < 0 ? 0 : offset;
}
return -1;
}
u16 __sanitizer_unaligned_load16(const uu16 *p) {
return *p;
}
u32 __sanitizer_unaligned_load32(const uu32 *p) {
return *p;
}
u64 __sanitizer_unaligned_load64(const uu64 *p) {
return *p;
}
void __sanitizer_unaligned_store16(uu16 *p, u16 x) {
*p = x;
}
void __sanitizer_unaligned_store32(uu32 *p, u32 x) {
*p = x;
}
void __sanitizer_unaligned_store64(uu64 *p, u64 x) {
*p = x;
}
void __hwasan_loadN(uptr p, uptr sz) {
CheckAddressSized<ErrorAction::Abort, AccessType::Load>(p, sz);
}
void __hwasan_load1(uptr p) {
CheckAddress<ErrorAction::Abort, AccessType::Load, 0>(p);
}
void __hwasan_load2(uptr p) {
CheckAddress<ErrorAction::Abort, AccessType::Load, 1>(p);
}
void __hwasan_load4(uptr p) {
CheckAddress<ErrorAction::Abort, AccessType::Load, 2>(p);
}
void __hwasan_load8(uptr p) {
CheckAddress<ErrorAction::Abort, AccessType::Load, 3>(p);
}
void __hwasan_load16(uptr p) {
CheckAddress<ErrorAction::Abort, AccessType::Load, 4>(p);
}
void __hwasan_loadN_noabort(uptr p, uptr sz) {
CheckAddressSized<ErrorAction::Recover, AccessType::Load>(p, sz);
}
void __hwasan_load1_noabort(uptr p) {
CheckAddress<ErrorAction::Recover, AccessType::Load, 0>(p);
}
void __hwasan_load2_noabort(uptr p) {
CheckAddress<ErrorAction::Recover, AccessType::Load, 1>(p);
}
void __hwasan_load4_noabort(uptr p) {
CheckAddress<ErrorAction::Recover, AccessType::Load, 2>(p);
}
void __hwasan_load8_noabort(uptr p) {
CheckAddress<ErrorAction::Recover, AccessType::Load, 3>(p);
}
void __hwasan_load16_noabort(uptr p) {
CheckAddress<ErrorAction::Recover, AccessType::Load, 4>(p);
}
void __hwasan_storeN(uptr p, uptr sz) {
CheckAddressSized<ErrorAction::Abort, AccessType::Store>(p, sz);
}
void __hwasan_store1(uptr p) {
CheckAddress<ErrorAction::Abort, AccessType::Store, 0>(p);
}
void __hwasan_store2(uptr p) {
CheckAddress<ErrorAction::Abort, AccessType::Store, 1>(p);
}
void __hwasan_store4(uptr p) {
CheckAddress<ErrorAction::Abort, AccessType::Store, 2>(p);
}
void __hwasan_store8(uptr p) {
CheckAddress<ErrorAction::Abort, AccessType::Store, 3>(p);
}
void __hwasan_store16(uptr p) {
CheckAddress<ErrorAction::Abort, AccessType::Store, 4>(p);
}
void __hwasan_storeN_noabort(uptr p, uptr sz) {
CheckAddressSized<ErrorAction::Recover, AccessType::Store>(p, sz);
}
void __hwasan_store1_noabort(uptr p) {
CheckAddress<ErrorAction::Recover, AccessType::Store, 0>(p);
}
void __hwasan_store2_noabort(uptr p) {
CheckAddress<ErrorAction::Recover, AccessType::Store, 1>(p);
}
void __hwasan_store4_noabort(uptr p) {
CheckAddress<ErrorAction::Recover, AccessType::Store, 2>(p);
}
void __hwasan_store8_noabort(uptr p) {
CheckAddress<ErrorAction::Recover, AccessType::Store, 3>(p);
}
void __hwasan_store16_noabort(uptr p) {
CheckAddress<ErrorAction::Recover, AccessType::Store, 4>(p);
}
void __hwasan_tag_memory(uptr p, u8 tag, uptr sz) {
TagMemoryAligned(p, sz, tag);
}
uptr __hwasan_tag_pointer(uptr p, u8 tag) {
return AddTagToPointer(p, tag);
}
void __hwasan_handle_longjmp(const void *sp_dst) {
uptr dst = (uptr)sp_dst;
// HWASan does not support tagged SP.
CHECK(GetTagFromPointer(dst) == 0);
uptr sp = (uptr)__builtin_frame_address(0);
static const uptr kMaxExpectedCleanupSize = 64 << 20; // 64M
if (dst < sp || dst - sp > kMaxExpectedCleanupSize) {
Report(
"WARNING: HWASan is ignoring requested __hwasan_handle_longjmp: "
"stack top: %p; target %p; distance: %p (%zd)\n"
"False positive error reports may follow\n",
(void *)sp, (void *)dst, dst - sp);
return;
}
TagMemory(sp, dst - sp, 0);
}
void __hwasan_handle_vfork(const void *sp_dst) {
uptr sp = (uptr)sp_dst;
Thread *t = GetCurrentThread();
CHECK(t);
uptr top = t->stack_top();
uptr bottom = t->stack_bottom();
if (top == 0 || bottom == 0 || sp < bottom || sp >= top) {
Report(
"WARNING: HWASan is ignoring requested __hwasan_handle_vfork: "
"stack top: %zx; current %zx; bottom: %zx \n"
"False positive error reports may follow\n",
top, sp, bottom);
return;
}
TagMemory(bottom, sp - bottom, 0);
}
extern "C" void *__hwasan_extra_spill_area() {
Thread *t = GetCurrentThread();
return &t->vfork_spill();
}
void __hwasan_print_memory_usage() {
InternalScopedString s;
HwasanFormatMemoryUsage(s);
Printf("%s\n", s.data());
}
static const u8 kFallbackTag = 0xBB & kTagMask;
u8 __hwasan_generate_tag() {
Thread *t = GetCurrentThread();
if (!t) return kFallbackTag;
return t->GenerateRandomTag();
}
#if !SANITIZER_SUPPORTS_WEAK_HOOKS
extern "C" {
SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE
const char* __hwasan_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();
}
// Entry point for interoperability between __hwasan_tag_mismatch (ASM) and the
// rest of the mismatch handling code (C++).
void __hwasan_tag_mismatch4(uptr addr, uptr access_info, uptr *registers_frame,
size_t outsize) {
__hwasan::HwasanTagMismatch(addr, access_info, registers_frame, outsize);
}
} // extern "C"