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//===-- asan_rtl.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 AddressSanitizer, an address sanity checker.
//
// Main file of the ASan run-time library.
//===----------------------------------------------------------------------===//
#include "asan_allocator.h"
#include "asan_interceptors.h"
#include "asan_interface.h"
#include "asan_internal.h"
#include "asan_lock.h"
#include "asan_mapping.h"
#include "asan_report.h"
#include "asan_stack.h"
#include "asan_stats.h"
#include "asan_thread.h"
#include "asan_thread_registry.h"
#include "sanitizer_common/sanitizer_atomic.h"
#include "sanitizer_common/sanitizer_flags.h"
#include "sanitizer_common/sanitizer_libc.h"
namespace __sanitizer {
using namespace __asan;
void Die() {
static atomic_uint32_t num_calls;
if (atomic_fetch_add(&num_calls, 1, memory_order_relaxed) != 0) {
// Don't die twice - run a busy loop.
while (1) { }
}
if (flags()->sleep_before_dying) {
Report("Sleeping for %d second(s)\n", flags()->sleep_before_dying);
SleepForSeconds(flags()->sleep_before_dying);
}
if (flags()->unmap_shadow_on_exit)
UnmapOrDie((void*)kLowShadowBeg, kHighShadowEnd - kLowShadowBeg);
if (death_callback)
death_callback();
if (flags()->abort_on_error)
Abort();
Exit(flags()->exitcode);
}
void CheckFailed(const char *file, int line, const char *cond, u64 v1, u64 v2) {
AsanReport("AddressSanitizer CHECK failed: %s:%d \"%s\" (0x%zx, 0x%zx)\n",
file, line, cond, (uptr)v1, (uptr)v2);
PRINT_CURRENT_STACK();
ShowStatsAndAbort();
}
} // namespace __sanitizer
namespace __asan {
// -------------------------- Flags ------------------------- {{{1
static const int kMallocContextSize = 30;
static Flags asan_flags;
Flags *flags() {
return &asan_flags;
}
static void ParseFlagsFromString(Flags *f, const char *str) {
ParseFlag(str, &f->quarantine_size, "quarantine_size");
ParseFlag(str, &f->symbolize, "symbolize");
ParseFlag(str, &f->verbosity, "verbosity");
ParseFlag(str, &f->redzone, "redzone");
CHECK(f->redzone >= 16);
CHECK(IsPowerOfTwo(f->redzone));
ParseFlag(str, &f->debug, "debug");
ParseFlag(str, &f->report_globals, "report_globals");
ParseFlag(str, &f->malloc_context_size, "malloc_context_size");
CHECK(f->malloc_context_size <= kMallocContextSize);
ParseFlag(str, &f->replace_str, "replace_str");
ParseFlag(str, &f->replace_intrin, "replace_intrin");
ParseFlag(str, &f->replace_cfallocator, "replace_cfallocator");
ParseFlag(str, &f->mac_ignore_invalid_free, "mac_ignore_invalid_free");
ParseFlag(str, &f->use_fake_stack, "use_fake_stack");
ParseFlag(str, &f->max_malloc_fill_size, "max_malloc_fill_size");
ParseFlag(str, &f->exitcode, "exitcode");
ParseFlag(str, &f->allow_user_poisoning, "allow_user_poisoning");
ParseFlag(str, &f->sleep_before_dying, "sleep_before_dying");
ParseFlag(str, &f->handle_segv, "handle_segv");
ParseFlag(str, &f->use_sigaltstack, "use_sigaltstack");
ParseFlag(str, &f->check_malloc_usable_size, "check_malloc_usable_size");
ParseFlag(str, &f->unmap_shadow_on_exit, "unmap_shadow_on_exit");
ParseFlag(str, &f->abort_on_error, "abort_on_error");
ParseFlag(str, &f->atexit, "atexit");
ParseFlag(str, &f->disable_core, "disable_core");
ParseFlag(str, &f->strip_path_prefix, "strip_path_prefix");
}
extern "C" {
SANITIZER_WEAK_ATTRIBUTE
SANITIZER_INTERFACE_ATTRIBUTE
const char* __asan_default_options() { return ""; }
} // extern "C"
void InitializeFlags(Flags *f, const char *env) {
internal_memset(f, 0, sizeof(*f));
f->quarantine_size = (ASAN_LOW_MEMORY) ? 1UL << 24 : 1UL << 28;
f->symbolize = false;
f->verbosity = 0;
f->redzone = (ASAN_LOW_MEMORY) ? 64 : 128;
f->debug = false;
f->report_globals = 1;
f->malloc_context_size = kMallocContextSize;
f->replace_str = true;
f->replace_intrin = true;
f->replace_cfallocator = true;
f->mac_ignore_invalid_free = false;
f->use_fake_stack = true;
f->max_malloc_fill_size = 0;
f->exitcode = ASAN_DEFAULT_FAILURE_EXITCODE;
f->allow_user_poisoning = true;
f->sleep_before_dying = 0;
f->handle_segv = ASAN_NEEDS_SEGV;
f->use_sigaltstack = false;
f->check_malloc_usable_size = true;
f->unmap_shadow_on_exit = false;
f->abort_on_error = false;
f->atexit = false;
f->disable_core = (__WORDSIZE == 64);
f->strip_path_prefix = "";
// Override from user-specified string.
ParseFlagsFromString(f, __asan_default_options());
if (flags()->verbosity) {
Report("Using the defaults from __asan_default_options: %s\n",
__asan_default_options());
}
// Override from command line.
ParseFlagsFromString(f, env);
}
// -------------------------- Globals --------------------- {{{1
int asan_inited;
bool asan_init_is_running;
void (*death_callback)(void);
// -------------------------- Misc ---------------- {{{1
void ShowStatsAndAbort() {
__asan_print_accumulated_stats();
Die();
}
// ---------------------- mmap -------------------- {{{1
// Reserve memory range [beg, end].
static void ReserveShadowMemoryRange(uptr beg, uptr end) {
CHECK((beg % kPageSize) == 0);
CHECK(((end + 1) % kPageSize) == 0);
uptr size = end - beg + 1;
void *res = MmapFixedNoReserve(beg, size);
CHECK(res == (void*)beg && "ReserveShadowMemoryRange failed");
}
// ---------------------- LowLevelAllocator ------------- {{{1
void *LowLevelAllocator::Allocate(uptr size) {
CHECK((size & (size - 1)) == 0 && "size must be a power of two");
if (allocated_end_ - allocated_current_ < (sptr)size) {
uptr size_to_allocate = Max(size, kPageSize);
allocated_current_ =
(char*)MmapOrDie(size_to_allocate, __FUNCTION__);
allocated_end_ = allocated_current_ + size_to_allocate;
PoisonShadow((uptr)allocated_current_, size_to_allocate,
kAsanInternalHeapMagic);
}
CHECK(allocated_end_ - allocated_current_ >= (sptr)size);
void *res = allocated_current_;
allocated_current_ += size;
return res;
}
// -------------------------- Run-time entry ------------------- {{{1
// exported functions
#define ASAN_REPORT_ERROR(type, is_write, size) \
extern "C" NOINLINE INTERFACE_ATTRIBUTE \
void __asan_report_ ## type ## size(uptr addr); \
void __asan_report_ ## type ## size(uptr addr) { \
GET_CALLER_PC_BP_SP; \
__asan_report_error(pc, bp, sp, addr, is_write, size); \
}
ASAN_REPORT_ERROR(load, false, 1)
ASAN_REPORT_ERROR(load, false, 2)
ASAN_REPORT_ERROR(load, false, 4)
ASAN_REPORT_ERROR(load, false, 8)
ASAN_REPORT_ERROR(load, false, 16)
ASAN_REPORT_ERROR(store, true, 1)
ASAN_REPORT_ERROR(store, true, 2)
ASAN_REPORT_ERROR(store, true, 4)
ASAN_REPORT_ERROR(store, true, 8)
ASAN_REPORT_ERROR(store, true, 16)
// Force the linker to keep the symbols for various ASan interface functions.
// We want to keep those in the executable in order to let the instrumented
// dynamic libraries access the symbol even if it is not used by the executable
// itself. This should help if the build system is removing dead code at link
// time.
static NOINLINE void force_interface_symbols() {
volatile int fake_condition = 0; // prevent dead condition elimination.
// __asan_report_* functions are noreturn, so we need a switch to prevent
// the compiler from removing any of them.
switch (fake_condition) {
case 1: __asan_report_load1(0); break;
case 2: __asan_report_load2(0); break;
case 3: __asan_report_load4(0); break;
case 4: __asan_report_load8(0); break;
case 5: __asan_report_load16(0); break;
case 6: __asan_report_store1(0); break;
case 7: __asan_report_store2(0); break;
case 8: __asan_report_store4(0); break;
case 9: __asan_report_store8(0); break;
case 10: __asan_report_store16(0); break;
case 11: __asan_register_global(0, 0, 0); break;
case 12: __asan_register_globals(0, 0); break;
case 13: __asan_unregister_globals(0, 0); break;
case 14: __asan_set_death_callback(0); break;
case 15: __asan_set_error_report_callback(0); break;
case 16: __asan_handle_no_return(); break;
case 17: __asan_address_is_poisoned(0); break;
case 18: __asan_get_allocated_size(0); break;
case 19: __asan_get_current_allocated_bytes(); break;
case 20: __asan_get_estimated_allocated_size(0); break;
case 21: __asan_get_free_bytes(); break;
case 22: __asan_get_heap_size(); break;
case 23: __asan_get_ownership(0); break;
case 24: __asan_get_unmapped_bytes(); break;
case 25: __asan_poison_memory_region(0, 0); break;
case 26: __asan_unpoison_memory_region(0, 0); break;
case 27: __asan_set_error_exit_code(0); break;
case 28: __asan_stack_free(0, 0, 0); break;
case 29: __asan_stack_malloc(0, 0); break;
case 30: __asan_set_on_error_callback(0); break;
}
}
static void asan_atexit() {
AsanPrintf("AddressSanitizer exit stats:\n");
__asan_print_accumulated_stats();
}
} // namespace __asan
// ---------------------- Interface ---------------- {{{1
using namespace __asan; // NOLINT
int NOINLINE __asan_set_error_exit_code(int exit_code) {
int old = flags()->exitcode;
flags()->exitcode = exit_code;
return old;
}
void NOINLINE __asan_handle_no_return() {
int local_stack;
AsanThread *curr_thread = asanThreadRegistry().GetCurrent();
CHECK(curr_thread);
uptr top = curr_thread->stack_top();
uptr bottom = ((uptr)&local_stack - kPageSize) & ~(kPageSize-1);
PoisonShadow(bottom, top - bottom, 0);
}
void NOINLINE __asan_set_death_callback(void (*callback)(void)) {
death_callback = callback;
}
void __asan_init() {
if (asan_inited) return;
asan_init_is_running = true;
// Make sure we are not statically linked.
AsanDoesNotSupportStaticLinkage();
// Initialize flags.
const char *options = GetEnv("ASAN_OPTIONS");
InitializeFlags(flags(), options);
if (flags()->verbosity && options) {
Report("Parsed ASAN_OPTIONS: %s\n", options);
}
if (flags()->atexit) {
Atexit(asan_atexit);
}
// interceptors
InitializeAsanInterceptors();
ReplaceSystemMalloc();
ReplaceOperatorsNewAndDelete();
if (flags()->verbosity) {
Printf("|| `[%p, %p]` || HighMem ||\n",
(void*)kHighMemBeg, (void*)kHighMemEnd);
Printf("|| `[%p, %p]` || HighShadow ||\n",
(void*)kHighShadowBeg, (void*)kHighShadowEnd);
Printf("|| `[%p, %p]` || ShadowGap ||\n",
(void*)kShadowGapBeg, (void*)kShadowGapEnd);
Printf("|| `[%p, %p]` || LowShadow ||\n",
(void*)kLowShadowBeg, (void*)kLowShadowEnd);
Printf("|| `[%p, %p]` || LowMem ||\n",
(void*)kLowMemBeg, (void*)kLowMemEnd);
Printf("MemToShadow(shadow): %p %p %p %p\n",
(void*)MEM_TO_SHADOW(kLowShadowBeg),
(void*)MEM_TO_SHADOW(kLowShadowEnd),
(void*)MEM_TO_SHADOW(kHighShadowBeg),
(void*)MEM_TO_SHADOW(kHighShadowEnd));
Printf("red_zone=%zu\n", (uptr)flags()->redzone);
Printf("malloc_context_size=%zu\n", (uptr)flags()->malloc_context_size);
Printf("SHADOW_SCALE: %zx\n", (uptr)SHADOW_SCALE);
Printf("SHADOW_GRANULARITY: %zx\n", (uptr)SHADOW_GRANULARITY);
Printf("SHADOW_OFFSET: %zx\n", (uptr)SHADOW_OFFSET);
CHECK(SHADOW_SCALE >= 3 && SHADOW_SCALE <= 7);
}
if (flags()->disable_core) {
DisableCoreDumper();
}
uptr shadow_start = kLowShadowBeg;
if (kLowShadowBeg > 0) shadow_start -= kMmapGranularity;
uptr shadow_end = kHighShadowEnd;
if (MemoryRangeIsAvailable(shadow_start, shadow_end)) {
if (kLowShadowBeg != kLowShadowEnd) {
// mmap the low shadow plus at least one page.
ReserveShadowMemoryRange(kLowShadowBeg - kMmapGranularity, kLowShadowEnd);
}
// mmap the high shadow.
ReserveShadowMemoryRange(kHighShadowBeg, kHighShadowEnd);
// protect the gap
void *prot = Mprotect(kShadowGapBeg, kShadowGapEnd - kShadowGapBeg + 1);
CHECK(prot == (void*)kShadowGapBeg);
} else {
Report("Shadow memory range interleaves with an existing memory mapping. "
"ASan cannot proceed correctly. ABORTING.\n");
DumpProcessMap();
Die();
}
InstallSignalHandlers();
// On Linux AsanThread::ThreadStart() calls malloc() that's why asan_inited
// should be set to 1 prior to initializing the threads.
asan_inited = 1;
asan_init_is_running = false;
asanThreadRegistry().Init();
asanThreadRegistry().GetMain()->ThreadStart();
force_interface_symbols(); // no-op.
if (flags()->verbosity) {
Report("AddressSanitizer Init done\n");
}
}
#if defined(ASAN_USE_PREINIT_ARRAY)
// On Linux, we force __asan_init to be called before anyone else
// by placing it into .preinit_array section.
// FIXME: do we have anything like this on Mac?
__attribute__((section(".preinit_array")))
typeof(__asan_init) *__asan_preinit =__asan_init;
#elif defined(_WIN32) && defined(_DLL)
// On Windows, when using dynamic CRT (/MD), we can put a pointer
// to __asan_init into the global list of C initializers.
// See crt0dat.c in the CRT sources for the details.
#pragma section(".CRT$XIB", long, read) // NOLINT
__declspec(allocate(".CRT$XIB")) void (*__asan_preinit)() = __asan_init;
#endif