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//===-- asan_interceptors.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.
//
// Intercept various libc functions.
//===----------------------------------------------------------------------===//
#include "asan_interceptors.h"
#include "asan_allocator.h"
#include "asan_internal.h"
#include "asan_mapping.h"
#include "asan_poisoning.h"
#include "asan_report.h"
#include "asan_stack.h"
#include "asan_stats.h"
#include "asan_suppressions.h"
#include "sanitizer_common/sanitizer_libc.h"
namespace __asan {
// Return true if we can quickly decide that the region is unpoisoned.
static inline bool QuickCheckForUnpoisonedRegion(uptr beg, uptr size) {
if (size == 0) return true;
if (size <= 32)
return !AddressIsPoisoned(beg) &&
!AddressIsPoisoned(beg + size - 1) &&
!AddressIsPoisoned(beg + size / 2);
return false;
}
struct AsanInterceptorContext {
const char *interceptor_name;
};
// We implement ACCESS_MEMORY_RANGE, ASAN_READ_RANGE,
// and ASAN_WRITE_RANGE as macro instead of function so
// that no extra frames are created, and stack trace contains
// relevant information only.
// We check all shadow bytes.
#define ACCESS_MEMORY_RANGE(ctx, offset, size, isWrite) do { \
uptr __offset = (uptr)(offset); \
uptr __size = (uptr)(size); \
uptr __bad = 0; \
if (__offset > __offset + __size) { \
GET_STACK_TRACE_FATAL_HERE; \
ReportStringFunctionSizeOverflow(__offset, __size, &stack); \
} \
if (!QuickCheckForUnpoisonedRegion(__offset, __size) && \
(__bad = __asan_region_is_poisoned(__offset, __size))) { \
AsanInterceptorContext *_ctx = (AsanInterceptorContext *)ctx; \
bool suppressed = false; \
if (_ctx) { \
suppressed = IsInterceptorSuppressed(_ctx->interceptor_name); \
if (!suppressed && HaveStackTraceBasedSuppressions()) { \
GET_STACK_TRACE_FATAL_HERE; \
suppressed = IsStackTraceSuppressed(&stack); \
} \
} \
if (!suppressed) { \
GET_CURRENT_PC_BP_SP; \
__asan_report_error(pc, bp, sp, __bad, isWrite, __size); \
} \
} \
} while (0)
#define ASAN_READ_RANGE(ctx, offset, size) \
ACCESS_MEMORY_RANGE(ctx, offset, size, false)
#define ASAN_WRITE_RANGE(ctx, offset, size) \
ACCESS_MEMORY_RANGE(ctx, offset, size, true)
// Behavior of functions like "memcpy" or "strcpy" is undefined
// if memory intervals overlap. We report error in this case.
// Macro is used to avoid creation of new frames.
static inline bool RangesOverlap(const char *offset1, uptr length1,
const char *offset2, uptr length2) {
return !((offset1 + length1 <= offset2) || (offset2 + length2 <= offset1));
}
#define CHECK_RANGES_OVERLAP(name, _offset1, length1, _offset2, length2) do { \
const char *offset1 = (const char*)_offset1; \
const char *offset2 = (const char*)_offset2; \
if (RangesOverlap(offset1, length1, offset2, length2)) { \
GET_STACK_TRACE_FATAL_HERE; \
ReportStringFunctionMemoryRangesOverlap(name, offset1, length1, \
offset2, length2, &stack); \
} \
} while (0)
static inline uptr MaybeRealStrnlen(const char *s, uptr maxlen) {
#if ASAN_INTERCEPT_STRNLEN
if (REAL(strnlen) != 0) {
return REAL(strnlen)(s, maxlen);
}
#endif
return internal_strnlen(s, maxlen);
}
void SetThreadName(const char *name) {
AsanThread *t = GetCurrentThread();
if (t)
asanThreadRegistry().SetThreadName(t->tid(), name);
}
int OnExit() {
// FIXME: ask frontend whether we need to return failure.
return 0;
}
} // namespace __asan
// ---------------------- Wrappers ---------------- {{{1
using namespace __asan; // NOLINT
DECLARE_REAL_AND_INTERCEPTOR(void *, malloc, uptr)
DECLARE_REAL_AND_INTERCEPTOR(void, free, void *)
#if !SANITIZER_MAC
#define ASAN_INTERCEPT_FUNC(name) \
do { \
if ((!INTERCEPT_FUNCTION(name) || !REAL(name))) \
VReport(1, "AddressSanitizer: failed to intercept '" #name "'\n"); \
} while (0)
#else
// OS X interceptors don't need to be initialized with INTERCEPT_FUNCTION.
#define ASAN_INTERCEPT_FUNC(name)
#endif // SANITIZER_MAC
#define ASAN_INTERCEPTOR_ENTER(ctx, func) \
AsanInterceptorContext _ctx = {#func}; \
ctx = (void *)&_ctx; \
(void) ctx; \
#define COMMON_INTERCEPT_FUNCTION(name) ASAN_INTERCEPT_FUNC(name)
#define COMMON_INTERCEPTOR_WRITE_RANGE(ctx, ptr, size) \
ASAN_WRITE_RANGE(ctx, ptr, size)
#define COMMON_INTERCEPTOR_READ_RANGE(ctx, ptr, size) \
ASAN_READ_RANGE(ctx, ptr, size)
#define COMMON_INTERCEPTOR_ENTER(ctx, func, ...) \
ASAN_INTERCEPTOR_ENTER(ctx, func); \
do { \
if (asan_init_is_running) \
return REAL(func)(__VA_ARGS__); \
if (SANITIZER_MAC && UNLIKELY(!asan_inited)) \
return REAL(func)(__VA_ARGS__); \
ENSURE_ASAN_INITED(); \
} while (false)
#define COMMON_INTERCEPTOR_DIR_ACQUIRE(ctx, path) \
do { \
} while (false)
#define COMMON_INTERCEPTOR_FD_ACQUIRE(ctx, fd) \
do { \
} while (false)
#define COMMON_INTERCEPTOR_FD_RELEASE(ctx, fd) \
do { \
} while (false)
#define COMMON_INTERCEPTOR_FD_SOCKET_ACCEPT(ctx, fd, newfd) \
do { \
} while (false)
#define COMMON_INTERCEPTOR_SET_THREAD_NAME(ctx, name) SetThreadName(name)
// Should be asanThreadRegistry().SetThreadNameByUserId(thread, name)
// But asan does not remember UserId's for threads (pthread_t);
// and remembers all ever existed threads, so the linear search by UserId
// can be slow.
#define COMMON_INTERCEPTOR_SET_PTHREAD_NAME(ctx, thread, name) \
do { \
} while (false)
#define COMMON_INTERCEPTOR_BLOCK_REAL(name) REAL(name)
// Strict init-order checking is dlopen-hostile:
// https://code.google.com/p/address-sanitizer/issues/detail?id=178
#define COMMON_INTERCEPTOR_ON_DLOPEN(filename, flag) \
if (flags()->strict_init_order) { \
StopInitOrderChecking(); \
}
#define COMMON_INTERCEPTOR_ON_EXIT(ctx) OnExit()
#define COMMON_INTERCEPTOR_LIBRARY_LOADED(filename, handle) \
CoverageUpdateMapping()
#define COMMON_INTERCEPTOR_LIBRARY_UNLOADED() CoverageUpdateMapping()
#define COMMON_INTERCEPTOR_NOTHING_IS_INITIALIZED (!asan_inited)
#include "sanitizer_common/sanitizer_common_interceptors.inc"
// Syscall interceptors don't have contexts, we don't support suppressions
// for them.
#define COMMON_SYSCALL_PRE_READ_RANGE(p, s) ASAN_READ_RANGE(nullptr, p, s)
#define COMMON_SYSCALL_PRE_WRITE_RANGE(p, s) ASAN_WRITE_RANGE(nullptr, p, s)
#define COMMON_SYSCALL_POST_READ_RANGE(p, s) \
do { \
(void)(p); \
(void)(s); \
} while (false)
#define COMMON_SYSCALL_POST_WRITE_RANGE(p, s) \
do { \
(void)(p); \
(void)(s); \
} while (false)
#include "sanitizer_common/sanitizer_common_syscalls.inc"
struct ThreadStartParam {
atomic_uintptr_t t;
atomic_uintptr_t is_registered;
};
static thread_return_t THREAD_CALLING_CONV asan_thread_start(void *arg) {
#if SANITIZER_WINDOWS
// FIXME: this is a bandaid fix for PR22025.
AsanThread *t = (AsanThread*)arg;
SetCurrentThread(t);
return t->ThreadStart(GetTid(), /* signal_thread_is_registered */ nullptr);
#else
ThreadStartParam *param = reinterpret_cast<ThreadStartParam *>(arg);
AsanThread *t = nullptr;
while ((t = reinterpret_cast<AsanThread *>(
atomic_load(&param->t, memory_order_acquire))) == 0)
internal_sched_yield();
SetCurrentThread(t);
return t->ThreadStart(GetTid(), &param->is_registered);
#endif
}
#if ASAN_INTERCEPT_PTHREAD_CREATE
INTERCEPTOR(int, pthread_create, void *thread,
void *attr, void *(*start_routine)(void*), void *arg) {
EnsureMainThreadIDIsCorrect();
// Strict init-order checking is thread-hostile.
if (flags()->strict_init_order)
StopInitOrderChecking();
GET_STACK_TRACE_THREAD;
int detached = 0;
if (attr != 0)
REAL(pthread_attr_getdetachstate)(attr, &detached);
ThreadStartParam param;
atomic_store(&param.t, 0, memory_order_relaxed);
atomic_store(&param.is_registered, 0, memory_order_relaxed);
int result = REAL(pthread_create)(thread, attr, asan_thread_start, &param);
if (result == 0) {
u32 current_tid = GetCurrentTidOrInvalid();
AsanThread *t =
AsanThread::Create(start_routine, arg, current_tid, &stack, detached);
atomic_store(&param.t, reinterpret_cast<uptr>(t), memory_order_release);
// Wait until the AsanThread object is initialized and the ThreadRegistry
// entry is in "started" state. One reason for this is that after this
// interceptor exits, the child thread's stack may be the only thing holding
// the |arg| pointer. This may cause LSan to report a leak if leak checking
// happens at a point when the interceptor has already exited, but the stack
// range for the child thread is not yet known.
while (atomic_load(&param.is_registered, memory_order_acquire) == 0)
internal_sched_yield();
}
return result;
}
INTERCEPTOR(int, pthread_join, void *t, void **arg) {
return real_pthread_join(t, arg);
}
DEFINE_REAL_PTHREAD_FUNCTIONS
#endif // ASAN_INTERCEPT_PTHREAD_CREATE
#if ASAN_INTERCEPT_SIGNAL_AND_SIGACTION
#if SANITIZER_ANDROID
INTERCEPTOR(void*, bsd_signal, int signum, void *handler) {
if (!IsDeadlySignal(signum) || common_flags()->allow_user_segv_handler) {
return REAL(bsd_signal)(signum, handler);
}
return 0;
}
#else
INTERCEPTOR(void*, signal, int signum, void *handler) {
if (!IsDeadlySignal(signum) || common_flags()->allow_user_segv_handler) {
return REAL(signal)(signum, handler);
}
return 0;
}
#endif
INTERCEPTOR(int, sigaction, int signum, const struct sigaction *act,
struct sigaction *oldact) {
if (!IsDeadlySignal(signum) || common_flags()->allow_user_segv_handler) {
return REAL(sigaction)(signum, act, oldact);
}
return 0;
}
namespace __sanitizer {
int real_sigaction(int signum, const void *act, void *oldact) {
return REAL(sigaction)(signum, (const struct sigaction *)act,
(struct sigaction *)oldact);
}
} // namespace __sanitizer
#elif SANITIZER_POSIX
// We need to have defined REAL(sigaction) on posix systems.
DEFINE_REAL(int, sigaction, int signum, const struct sigaction *act,
struct sigaction *oldact)
#endif // ASAN_INTERCEPT_SIGNAL_AND_SIGACTION
#if ASAN_INTERCEPT_SWAPCONTEXT
static void ClearShadowMemoryForContextStack(uptr stack, uptr ssize) {
// Align to page size.
uptr PageSize = GetPageSizeCached();
uptr bottom = stack & ~(PageSize - 1);
ssize += stack - bottom;
ssize = RoundUpTo(ssize, PageSize);
static const uptr kMaxSaneContextStackSize = 1 << 22; // 4 Mb
if (ssize && ssize <= kMaxSaneContextStackSize) {
PoisonShadow(bottom, ssize, 0);
}
}
INTERCEPTOR(int, swapcontext, struct ucontext_t *oucp,
struct ucontext_t *ucp) {
static bool reported_warning = false;
if (!reported_warning) {
Report("WARNING: ASan doesn't fully support makecontext/swapcontext "
"functions and may produce false positives in some cases!\n");
reported_warning = true;
}
// Clear shadow memory for new context (it may share stack
// with current context).
uptr stack, ssize;
ReadContextStack(ucp, &stack, &ssize);
ClearShadowMemoryForContextStack(stack, ssize);
int res = REAL(swapcontext)(oucp, ucp);
// swapcontext technically does not return, but program may swap context to
// "oucp" later, that would look as if swapcontext() returned 0.
// We need to clear shadow for ucp once again, as it may be in arbitrary
// state.
ClearShadowMemoryForContextStack(stack, ssize);
return res;
}
#endif // ASAN_INTERCEPT_SWAPCONTEXT
INTERCEPTOR(void, longjmp, void *env, int val) {
__asan_handle_no_return();
REAL(longjmp)(env, val);
}
#if ASAN_INTERCEPT__LONGJMP
INTERCEPTOR(void, _longjmp, void *env, int val) {
__asan_handle_no_return();
REAL(_longjmp)(env, val);
}
#endif
#if ASAN_INTERCEPT_SIGLONGJMP
INTERCEPTOR(void, siglongjmp, void *env, int val) {
__asan_handle_no_return();
REAL(siglongjmp)(env, val);
}
#endif
#if ASAN_INTERCEPT___CXA_THROW
INTERCEPTOR(void, __cxa_throw, void *a, void *b, void *c) {
CHECK(REAL(__cxa_throw));
__asan_handle_no_return();
REAL(__cxa_throw)(a, b, c);
}
#endif
#if SANITIZER_WINDOWS
INTERCEPTOR_WINAPI(void, RaiseException, void *a, void *b, void *c, void *d) {
CHECK(REAL(RaiseException));
__asan_handle_no_return();
REAL(RaiseException)(a, b, c, d);
}
INTERCEPTOR(int, _except_handler3, void *a, void *b, void *c, void *d) {
CHECK(REAL(_except_handler3));
__asan_handle_no_return();
return REAL(_except_handler3)(a, b, c, d);
}
#if ASAN_DYNAMIC
// This handler is named differently in -MT and -MD CRTs.
#define _except_handler4 _except_handler4_common
#endif
INTERCEPTOR(int, _except_handler4, void *a, void *b, void *c, void *d) {
CHECK(REAL(_except_handler4));
__asan_handle_no_return();
return REAL(_except_handler4)(a, b, c, d);
}
#endif
static inline int CharCmp(unsigned char c1, unsigned char c2) {
return (c1 == c2) ? 0 : (c1 < c2) ? -1 : 1;
}
INTERCEPTOR(int, memcmp, const void *a1, const void *a2, uptr size) {
void *ctx;
ASAN_INTERCEPTOR_ENTER(ctx, memcmp);
if (UNLIKELY(!asan_inited)) return internal_memcmp(a1, a2, size);
ENSURE_ASAN_INITED();
if (flags()->replace_intrin) {
if (flags()->strict_memcmp) {
// Check the entire regions even if the first bytes of the buffers are
// different.
ASAN_READ_RANGE(ctx, a1, size);
ASAN_READ_RANGE(ctx, a2, size);
// Fallthrough to REAL(memcmp) below.
} else {
unsigned char c1 = 0, c2 = 0;
const unsigned char *s1 = (const unsigned char*)a1;
const unsigned char *s2 = (const unsigned char*)a2;
uptr i;
for (i = 0; i < size; i++) {
c1 = s1[i];
c2 = s2[i];
if (c1 != c2) break;
}
ASAN_READ_RANGE(ctx, s1, Min(i + 1, size));
ASAN_READ_RANGE(ctx, s2, Min(i + 1, size));
return CharCmp(c1, c2);
}
}
return REAL(memcmp(a1, a2, size));
}
// memcpy is called during __asan_init() from the internals of printf(...).
// We do not treat memcpy with to==from as a bug.
// See http://llvm.org/bugs/show_bug.cgi?id=11763.
#define ASAN_MEMCPY_IMPL(ctx, to, from, size) do { \
if (UNLIKELY(!asan_inited)) return internal_memcpy(to, from, size); \
if (asan_init_is_running) { \
return REAL(memcpy)(to, from, size); \
} \
ENSURE_ASAN_INITED(); \
if (flags()->replace_intrin) { \
if (to != from) { \
CHECK_RANGES_OVERLAP("memcpy", to, size, from, size); \
} \
ASAN_READ_RANGE(ctx, from, size); \
ASAN_WRITE_RANGE(ctx, to, size); \
} \
return REAL(memcpy)(to, from, size); \
} while (0)
void *__asan_memcpy(void *to, const void *from, uptr size) {
ASAN_MEMCPY_IMPL(nullptr, to, from, size);
}
// memset is called inside Printf.
#define ASAN_MEMSET_IMPL(ctx, block, c, size) do { \
if (UNLIKELY(!asan_inited)) return internal_memset(block, c, size); \
if (asan_init_is_running) { \
return REAL(memset)(block, c, size); \
} \
ENSURE_ASAN_INITED(); \
if (flags()->replace_intrin) { \
ASAN_WRITE_RANGE(ctx, block, size); \
} \
return REAL(memset)(block, c, size); \
} while (0)
void *__asan_memset(void *block, int c, uptr size) {
ASAN_MEMSET_IMPL(nullptr, block, c, size);
}
#define ASAN_MEMMOVE_IMPL(ctx, to, from, size) do { \
if (UNLIKELY(!asan_inited)) \
return internal_memmove(to, from, size); \
ENSURE_ASAN_INITED(); \
if (flags()->replace_intrin) { \
ASAN_READ_RANGE(ctx, from, size); \
ASAN_WRITE_RANGE(ctx, to, size); \
} \
return internal_memmove(to, from, size); \
} while (0)
void *__asan_memmove(void *to, const void *from, uptr size) {
ASAN_MEMMOVE_IMPL(nullptr, to, from, size);
}
INTERCEPTOR(void*, memmove, void *to, const void *from, uptr size) {
void *ctx;
ASAN_INTERCEPTOR_ENTER(ctx, memmove);
ASAN_MEMMOVE_IMPL(ctx, to, from, size);
}
INTERCEPTOR(void*, memcpy, void *to, const void *from, uptr size) {
void *ctx;
ASAN_INTERCEPTOR_ENTER(ctx, memcpy);
#if !SANITIZER_MAC
ASAN_MEMCPY_IMPL(ctx, to, from, size);
#else
// At least on 10.7 and 10.8 both memcpy() and memmove() are being replaced
// with WRAP(memcpy). As a result, false positives are reported for memmove()
// calls. If we just disable error reporting with
// ASAN_OPTIONS=replace_intrin=0, memmove() is still replaced with
// internal_memcpy(), which may lead to crashes, see
// http://llvm.org/bugs/show_bug.cgi?id=16362.
ASAN_MEMMOVE_IMPL(ctx, to, from, size);
#endif // !SANITIZER_MAC
}
INTERCEPTOR(void*, memset, void *block, int c, uptr size) {
void *ctx;
ASAN_INTERCEPTOR_ENTER(ctx, memset);
ASAN_MEMSET_IMPL(ctx, block, c, size);
}
INTERCEPTOR(char*, strchr, const char *str, int c) {
void *ctx;
ASAN_INTERCEPTOR_ENTER(ctx, strchr);
if (UNLIKELY(!asan_inited)) return internal_strchr(str, c);
// strchr is called inside create_purgeable_zone() when MallocGuardEdges=1 is
// used.
if (asan_init_is_running) {
return REAL(strchr)(str, c);
}
ENSURE_ASAN_INITED();
char *result = REAL(strchr)(str, c);
if (flags()->replace_str) {
uptr bytes_read = (result ? result - str : REAL(strlen)(str)) + 1;
ASAN_READ_RANGE(ctx, str, bytes_read);
}
return result;
}
#if ASAN_INTERCEPT_INDEX
# if ASAN_USE_ALIAS_ATTRIBUTE_FOR_INDEX
INTERCEPTOR(char*, index, const char *string, int c)
ALIAS(WRAPPER_NAME(strchr));
# else
# if SANITIZER_MAC
DECLARE_REAL(char*, index, const char *string, int c)
OVERRIDE_FUNCTION(index, strchr);
# else
DEFINE_REAL(char*, index, const char *string, int c)
# endif
# endif
#endif // ASAN_INTERCEPT_INDEX
// For both strcat() and strncat() we need to check the validity of |to|
// argument irrespective of the |from| length.
INTERCEPTOR(char*, strcat, char *to, const char *from) { // NOLINT
void *ctx;
ASAN_INTERCEPTOR_ENTER(ctx, strcat); // NOLINT
ENSURE_ASAN_INITED();
if (flags()->replace_str) {
uptr from_length = REAL(strlen)(from);
ASAN_READ_RANGE(ctx, from, from_length + 1);
uptr to_length = REAL(strlen)(to);
ASAN_READ_RANGE(ctx, to, to_length);
ASAN_WRITE_RANGE(ctx, to + to_length, from_length + 1);
// If the copying actually happens, the |from| string should not overlap
// with the resulting string starting at |to|, which has a length of
// to_length + from_length + 1.
if (from_length > 0) {
CHECK_RANGES_OVERLAP("strcat", to, from_length + to_length + 1,
from, from_length + 1);
}
}
return REAL(strcat)(to, from); // NOLINT
}
INTERCEPTOR(char*, strncat, char *to, const char *from, uptr size) {
void *ctx;
ASAN_INTERCEPTOR_ENTER(ctx, strncat);
ENSURE_ASAN_INITED();
if (flags()->replace_str) {
uptr from_length = MaybeRealStrnlen(from, size);
uptr copy_length = Min(size, from_length + 1);
ASAN_READ_RANGE(ctx, from, copy_length);
uptr to_length = REAL(strlen)(to);
ASAN_READ_RANGE(ctx, to, to_length);
ASAN_WRITE_RANGE(ctx, to + to_length, from_length + 1);
if (from_length > 0) {
CHECK_RANGES_OVERLAP("strncat", to, to_length + copy_length + 1,
from, copy_length);
}
}
return REAL(strncat)(to, from, size);
}
INTERCEPTOR(char*, strcpy, char *to, const char *from) { // NOLINT
void *ctx;
ASAN_INTERCEPTOR_ENTER(ctx, strcpy); // NOLINT
#if SANITIZER_MAC
if (UNLIKELY(!asan_inited)) return REAL(strcpy)(to, from); // NOLINT
#endif
// strcpy is called from malloc_default_purgeable_zone()
// in __asan::ReplaceSystemAlloc() on Mac.
if (asan_init_is_running) {
return REAL(strcpy)(to, from); // NOLINT
}
ENSURE_ASAN_INITED();
if (flags()->replace_str) {
uptr from_size = REAL(strlen)(from) + 1;
CHECK_RANGES_OVERLAP("strcpy", to, from_size, from, from_size);
ASAN_READ_RANGE(ctx, from, from_size);
ASAN_WRITE_RANGE(ctx, to, from_size);
}
return REAL(strcpy)(to, from); // NOLINT
}
#if ASAN_INTERCEPT_STRDUP
INTERCEPTOR(char*, strdup, const char *s) {
void *ctx;
ASAN_INTERCEPTOR_ENTER(ctx, strdup);
if (UNLIKELY(!asan_inited)) return internal_strdup(s);
ENSURE_ASAN_INITED();
uptr length = REAL(strlen)(s);
if (flags()->replace_str) {
ASAN_READ_RANGE(ctx, s, length + 1);
}
GET_STACK_TRACE_MALLOC;
void *new_mem = asan_malloc(length + 1, &stack);
REAL(memcpy)(new_mem, s, length + 1);
return reinterpret_cast<char*>(new_mem);
}
#endif
INTERCEPTOR(SIZE_T, strlen, const char *s) {
void *ctx;
ASAN_INTERCEPTOR_ENTER(ctx, strlen);
if (UNLIKELY(!asan_inited)) return internal_strlen(s);
// strlen is called from malloc_default_purgeable_zone()
// in __asan::ReplaceSystemAlloc() on Mac.
if (asan_init_is_running) {
return REAL(strlen)(s);
}
ENSURE_ASAN_INITED();
SIZE_T length = REAL(strlen)(s);
if (flags()->replace_str) {
ASAN_READ_RANGE(ctx, s, length + 1);
}
return length;
}
INTERCEPTOR(SIZE_T, wcslen, const wchar_t *s) {
void *ctx;
ASAN_INTERCEPTOR_ENTER(ctx, wcslen);
SIZE_T length = REAL(wcslen)(s);
if (!asan_init_is_running) {
ENSURE_ASAN_INITED();
ASAN_READ_RANGE(ctx, s, (length + 1) * sizeof(wchar_t));
}
return length;
}
INTERCEPTOR(char*, strncpy, char *to, const char *from, uptr size) {
void *ctx;
ASAN_INTERCEPTOR_ENTER(ctx, strncpy);
ENSURE_ASAN_INITED();
if (flags()->replace_str) {
uptr from_size = Min(size, MaybeRealStrnlen(from, size) + 1);
CHECK_RANGES_OVERLAP("strncpy", to, from_size, from, from_size);
ASAN_READ_RANGE(ctx, from, from_size);
ASAN_WRITE_RANGE(ctx, to, size);
}
return REAL(strncpy)(to, from, size);
}
#if ASAN_INTERCEPT_STRNLEN
INTERCEPTOR(uptr, strnlen, const char *s, uptr maxlen) {
void *ctx;
ASAN_INTERCEPTOR_ENTER(ctx, strnlen);
ENSURE_ASAN_INITED();
uptr length = REAL(strnlen)(s, maxlen);
if (flags()->replace_str) {
ASAN_READ_RANGE(ctx, s, Min(length + 1, maxlen));
}
return length;
}
#endif // ASAN_INTERCEPT_STRNLEN
static inline bool IsValidStrtolBase(int base) {
return (base == 0) || (2 <= base && base <= 36);
}
static inline void FixRealStrtolEndptr(const char *nptr, char **endptr) {
CHECK(endptr);
if (nptr == *endptr) {
// No digits were found at strtol call, we need to find out the last
// symbol accessed by strtoll on our own.
// We get this symbol by skipping leading blanks and optional +/- sign.
while (IsSpace(*nptr)) nptr++;
if (*nptr == '+' || *nptr == '-') nptr++;
*endptr = const_cast<char *>(nptr);
}
CHECK(*endptr >= nptr);
}
INTERCEPTOR(long, strtol, const char *nptr, // NOLINT
char **endptr, int base) {
void *ctx;
ASAN_INTERCEPTOR_ENTER(ctx, strtol);
ENSURE_ASAN_INITED();
if (!flags()->replace_str) {
return REAL(strtol)(nptr, endptr, base);
}
char *real_endptr;
long result = REAL(strtol)(nptr, &real_endptr, base); // NOLINT
if (endptr != 0) {
*endptr = real_endptr;
}
if (IsValidStrtolBase(base)) {
FixRealStrtolEndptr(nptr, &real_endptr);
ASAN_READ_RANGE(ctx, nptr, (real_endptr - nptr) + 1);
}
return result;
}
INTERCEPTOR(int, atoi, const char *nptr) {
void *ctx;
ASAN_INTERCEPTOR_ENTER(ctx, atoi);
#if SANITIZER_MAC
if (UNLIKELY(!asan_inited)) return REAL(atoi)(nptr);
#endif
ENSURE_ASAN_INITED();
if (!flags()->replace_str) {
return REAL(atoi)(nptr);
}
char *real_endptr;
// "man atoi" tells that behavior of atoi(nptr) is the same as
// strtol(nptr, 0, 10), i.e. it sets errno to ERANGE if the
// parsed integer can't be stored in *long* type (even if it's
// different from int). So, we just imitate this behavior.
int result = REAL(strtol)(nptr, &real_endptr, 10);
FixRealStrtolEndptr(nptr, &real_endptr);
ASAN_READ_RANGE(ctx, nptr, (real_endptr - nptr) + 1);
return result;
}
INTERCEPTOR(long, atol, const char *nptr) { // NOLINT
void *ctx;
ASAN_INTERCEPTOR_ENTER(ctx, atol);
#if SANITIZER_MAC
if (UNLIKELY(!asan_inited)) return REAL(atol)(nptr);
#endif
ENSURE_ASAN_INITED();
if (!flags()->replace_str) {
return REAL(atol)(nptr);
}
char *real_endptr;
long result = REAL(strtol)(nptr, &real_endptr, 10); // NOLINT
FixRealStrtolEndptr(nptr, &real_endptr);
ASAN_READ_RANGE(ctx, nptr, (real_endptr - nptr) + 1);
return result;
}
#if ASAN_INTERCEPT_ATOLL_AND_STRTOLL
INTERCEPTOR(long long, strtoll, const char *nptr, // NOLINT
char **endptr, int base) {
void *ctx;
ASAN_INTERCEPTOR_ENTER(ctx, strtoll);
ENSURE_ASAN_INITED();
if (!flags()->replace_str) {
return REAL(strtoll)(nptr, endptr, base);
}
char *real_endptr;
long long result = REAL(strtoll)(nptr, &real_endptr, base); // NOLINT
if (endptr != 0) {
*endptr = real_endptr;
}
// If base has unsupported value, strtoll can exit with EINVAL
// without reading any characters. So do additional checks only
// if base is valid.
if (IsValidStrtolBase(base)) {
FixRealStrtolEndptr(nptr, &real_endptr);
ASAN_READ_RANGE(ctx, nptr, (real_endptr - nptr) + 1);
}
return result;
}
INTERCEPTOR(long long, atoll, const char *nptr) { // NOLINT
void *ctx;
ASAN_INTERCEPTOR_ENTER(ctx, atoll);
ENSURE_ASAN_INITED();
if (!flags()->replace_str) {
return REAL(atoll)(nptr);
}
char *real_endptr;
long long result = REAL(strtoll)(nptr, &real_endptr, 10); // NOLINT
FixRealStrtolEndptr(nptr, &real_endptr);
ASAN_READ_RANGE(ctx, nptr, (real_endptr - nptr) + 1);
return result;
}
#endif // ASAN_INTERCEPT_ATOLL_AND_STRTOLL
static void AtCxaAtexit(void *unused) {
(void)unused;
StopInitOrderChecking();
}
#if ASAN_INTERCEPT___CXA_ATEXIT
INTERCEPTOR(int, __cxa_atexit, void (*func)(void *), void *arg,
void *dso_handle) {
#if SANITIZER_MAC
if (UNLIKELY(!asan_inited)) return REAL(__cxa_atexit)(func, arg, dso_handle);
#endif
ENSURE_ASAN_INITED();
int res = REAL(__cxa_atexit)(func, arg, dso_handle);
REAL(__cxa_atexit)(AtCxaAtexit, 0, 0);
return res;
}
#endif // ASAN_INTERCEPT___CXA_ATEXIT
#if ASAN_INTERCEPT_FORK
INTERCEPTOR(int, fork, void) {
ENSURE_ASAN_INITED();
if (common_flags()->coverage) CovBeforeFork();
int pid = REAL(fork)();
if (common_flags()->coverage) CovAfterFork(pid);
return pid;
}
#endif // ASAN_INTERCEPT_FORK
#if SANITIZER_WINDOWS
INTERCEPTOR_WINAPI(DWORD, CreateThread,
void* security, uptr stack_size,
DWORD (__stdcall *start_routine)(void*), void* arg,
DWORD thr_flags, void* tid) {
// Strict init-order checking is thread-hostile.
if (flags()->strict_init_order)
StopInitOrderChecking();
GET_STACK_TRACE_THREAD;
// FIXME: The CreateThread interceptor is not the same as a pthread_create
// one. This is a bandaid fix for PR22025.
bool detached = false; // FIXME: how can we determine it on Windows?
u32 current_tid = GetCurrentTidOrInvalid();
AsanThread *t =
AsanThread::Create(start_routine, arg, current_tid, &stack, detached);
return REAL(CreateThread)(security, stack_size,
asan_thread_start, t, thr_flags, tid);
}
namespace __asan {
void InitializeWindowsInterceptors() {
ASAN_INTERCEPT_FUNC(CreateThread);
ASAN_INTERCEPT_FUNC(RaiseException);
ASAN_INTERCEPT_FUNC(_except_handler3);
ASAN_INTERCEPT_FUNC(_except_handler4);
}
} // namespace __asan
#endif
// ---------------------- InitializeAsanInterceptors ---------------- {{{1
namespace __asan {
void InitializeAsanInterceptors() {
static bool was_called_once;
CHECK(was_called_once == false);
was_called_once = true;
InitializeCommonInterceptors();
// Intercept mem* functions.
ASAN_INTERCEPT_FUNC(memcmp);
ASAN_INTERCEPT_FUNC(memmove);
ASAN_INTERCEPT_FUNC(memset);
if (PLATFORM_HAS_DIFFERENT_MEMCPY_AND_MEMMOVE) {
ASAN_INTERCEPT_FUNC(memcpy);
}
// Intercept str* functions.
ASAN_INTERCEPT_FUNC(strcat); // NOLINT
ASAN_INTERCEPT_FUNC(strchr);
ASAN_INTERCEPT_FUNC(strcpy); // NOLINT
ASAN_INTERCEPT_FUNC(strlen);
ASAN_INTERCEPT_FUNC(wcslen);
ASAN_INTERCEPT_FUNC(strncat);
ASAN_INTERCEPT_FUNC(strncpy);
#if ASAN_INTERCEPT_STRDUP
ASAN_INTERCEPT_FUNC(strdup);
#endif
#if ASAN_INTERCEPT_STRNLEN
ASAN_INTERCEPT_FUNC(strnlen);
#endif
#if ASAN_INTERCEPT_INDEX && ASAN_USE_ALIAS_ATTRIBUTE_FOR_INDEX
ASAN_INTERCEPT_FUNC(index);
#endif
ASAN_INTERCEPT_FUNC(atoi);
ASAN_INTERCEPT_FUNC(atol);
ASAN_INTERCEPT_FUNC(strtol);
#if ASAN_INTERCEPT_ATOLL_AND_STRTOLL
ASAN_INTERCEPT_FUNC(atoll);
ASAN_INTERCEPT_FUNC(strtoll);
#endif
// Intecept signal- and jump-related functions.
ASAN_INTERCEPT_FUNC(longjmp);
#if ASAN_INTERCEPT_SIGNAL_AND_SIGACTION
ASAN_INTERCEPT_FUNC(sigaction);
#if SANITIZER_ANDROID
ASAN_INTERCEPT_FUNC(bsd_signal);
#else
ASAN_INTERCEPT_FUNC(signal);
#endif
#endif
#if ASAN_INTERCEPT_SWAPCONTEXT
ASAN_INTERCEPT_FUNC(swapcontext);
#endif
#if ASAN_INTERCEPT__LONGJMP
ASAN_INTERCEPT_FUNC(_longjmp);
#endif
#if ASAN_INTERCEPT_SIGLONGJMP
ASAN_INTERCEPT_FUNC(siglongjmp);
#endif
// Intercept exception handling functions.
#if ASAN_INTERCEPT___CXA_THROW
ASAN_INTERCEPT_FUNC(__cxa_throw);
#endif
// Intercept threading-related functions
#if ASAN_INTERCEPT_PTHREAD_CREATE
ASAN_INTERCEPT_FUNC(pthread_create);
ASAN_INTERCEPT_FUNC(pthread_join);
#endif
// Intercept atexit function.
#if ASAN_INTERCEPT___CXA_ATEXIT
ASAN_INTERCEPT_FUNC(__cxa_atexit);
#endif
#if ASAN_INTERCEPT_FORK
ASAN_INTERCEPT_FUNC(fork);
#endif
// Some Windows-specific interceptors.
#if SANITIZER_WINDOWS
InitializeWindowsInterceptors();
#endif
VReport(1, "AddressSanitizer: libc interceptors initialized\n");
}
} // namespace __asan