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//===-- asan_malloc_linux.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.
//
// Linux-specific malloc interception.
// We simply define functions like malloc, free, realloc, etc.
// They will replace the corresponding libc functions automagically.
//===----------------------------------------------------------------------===//
#include "sanitizer_common/sanitizer_platform.h"
#if SANITIZER_FREEBSD || SANITIZER_FUCHSIA || SANITIZER_LINUX || \
SANITIZER_NETBSD || SANITIZER_RTEMS || SANITIZER_SOLARIS
#include "sanitizer_common/sanitizer_allocator_checks.h"
#include "sanitizer_common/sanitizer_errno.h"
#include "sanitizer_common/sanitizer_tls_get_addr.h"
#include "asan_allocator.h"
#include "asan_interceptors.h"
#include "asan_internal.h"
#include "asan_malloc_local.h"
#include "asan_stack.h"
// ---------------------- Replacement functions ---------------- {{{1
using namespace __asan; // NOLINT
static uptr allocated_for_dlsym;
static uptr last_dlsym_alloc_size_in_words;
static const uptr kDlsymAllocPoolSize = SANITIZER_RTEMS ? 4096 : 1024;
static uptr alloc_memory_for_dlsym[kDlsymAllocPoolSize];
static INLINE bool IsInDlsymAllocPool(const void *ptr) {
uptr off = (uptr)ptr - (uptr)alloc_memory_for_dlsym;
return off < allocated_for_dlsym * sizeof(alloc_memory_for_dlsym[0]);
}
static void *AllocateFromLocalPool(uptr size_in_bytes) {
uptr size_in_words = RoundUpTo(size_in_bytes, kWordSize) / kWordSize;
void *mem = (void*)&alloc_memory_for_dlsym[allocated_for_dlsym];
last_dlsym_alloc_size_in_words = size_in_words;
allocated_for_dlsym += size_in_words;
CHECK_LT(allocated_for_dlsym, kDlsymAllocPoolSize);
return mem;
}
static void DeallocateFromLocalPool(const void *ptr) {
// Hack: since glibc 2.27 dlsym no longer uses stack-allocated memory to store
// error messages and instead uses malloc followed by free. To avoid pool
// exhaustion due to long object filenames, handle that special case here.
uptr prev_offset = allocated_for_dlsym - last_dlsym_alloc_size_in_words;
void *prev_mem = (void*)&alloc_memory_for_dlsym[prev_offset];
if (prev_mem == ptr) {
REAL(memset)(prev_mem, 0, last_dlsym_alloc_size_in_words * kWordSize);
allocated_for_dlsym = prev_offset;
last_dlsym_alloc_size_in_words = 0;
}
}
static int PosixMemalignFromLocalPool(void **memptr, uptr alignment,
uptr size_in_bytes) {
if (UNLIKELY(!CheckPosixMemalignAlignment(alignment)))
return errno_EINVAL;
CHECK(alignment >= kWordSize);
uptr addr = (uptr)&alloc_memory_for_dlsym[allocated_for_dlsym];
uptr aligned_addr = RoundUpTo(addr, alignment);
uptr aligned_size = RoundUpTo(size_in_bytes, kWordSize);
uptr *end_mem = (uptr*)(aligned_addr + aligned_size);
uptr allocated = end_mem - alloc_memory_for_dlsym;
if (allocated >= kDlsymAllocPoolSize)
return errno_ENOMEM;
allocated_for_dlsym = allocated;
*memptr = (void*)aligned_addr;
return 0;
}
#if SANITIZER_RTEMS
void* MemalignFromLocalPool(uptr alignment, uptr size) {
void *ptr = nullptr;
alignment = Max(alignment, kWordSize);
PosixMemalignFromLocalPool(&ptr, alignment, size);
return ptr;
}
bool IsFromLocalPool(const void *ptr) {
return IsInDlsymAllocPool(ptr);
}
#endif
static INLINE bool MaybeInDlsym() {
// Fuchsia doesn't use dlsym-based interceptors.
return !SANITIZER_FUCHSIA && asan_init_is_running;
}
static INLINE bool UseLocalPool() {
return EarlyMalloc() || MaybeInDlsym();
}
static void *ReallocFromLocalPool(void *ptr, uptr size) {
const uptr offset = (uptr)ptr - (uptr)alloc_memory_for_dlsym;
const uptr copy_size = Min(size, kDlsymAllocPoolSize - offset);
void *new_ptr;
if (UNLIKELY(UseLocalPool())) {
new_ptr = AllocateFromLocalPool(size);
} else {
ENSURE_ASAN_INITED();
GET_STACK_TRACE_MALLOC;
new_ptr = asan_malloc(size, &stack);
}
internal_memcpy(new_ptr, ptr, copy_size);
return new_ptr;
}
INTERCEPTOR(void, free, void *ptr) {
GET_STACK_TRACE_FREE;
if (UNLIKELY(IsInDlsymAllocPool(ptr))) {
DeallocateFromLocalPool(ptr);
return;
}
asan_free(ptr, &stack, FROM_MALLOC);
}
#if SANITIZER_INTERCEPT_CFREE
INTERCEPTOR(void, cfree, void *ptr) {
GET_STACK_TRACE_FREE;
if (UNLIKELY(IsInDlsymAllocPool(ptr)))
return;
asan_free(ptr, &stack, FROM_MALLOC);
}
#endif // SANITIZER_INTERCEPT_CFREE
INTERCEPTOR(void*, malloc, uptr size) {
if (UNLIKELY(UseLocalPool()))
// Hack: dlsym calls malloc before REAL(malloc) is retrieved from dlsym.
return AllocateFromLocalPool(size);
ENSURE_ASAN_INITED();
GET_STACK_TRACE_MALLOC;
return asan_malloc(size, &stack);
}
INTERCEPTOR(void*, calloc, uptr nmemb, uptr size) {
if (UNLIKELY(UseLocalPool()))
// Hack: dlsym calls calloc before REAL(calloc) is retrieved from dlsym.
return AllocateFromLocalPool(nmemb * size);
ENSURE_ASAN_INITED();
GET_STACK_TRACE_MALLOC;
return asan_calloc(nmemb, size, &stack);
}
INTERCEPTOR(void*, realloc, void *ptr, uptr size) {
if (UNLIKELY(IsInDlsymAllocPool(ptr)))
return ReallocFromLocalPool(ptr, size);
if (UNLIKELY(UseLocalPool()))
return AllocateFromLocalPool(size);
ENSURE_ASAN_INITED();
GET_STACK_TRACE_MALLOC;
return asan_realloc(ptr, size, &stack);
}
#if SANITIZER_INTERCEPT_MEMALIGN
INTERCEPTOR(void*, memalign, uptr boundary, uptr size) {
GET_STACK_TRACE_MALLOC;
return asan_memalign(boundary, size, &stack, FROM_MALLOC);
}
INTERCEPTOR(void*, __libc_memalign, uptr boundary, uptr size) {
GET_STACK_TRACE_MALLOC;
void *res = asan_memalign(boundary, size, &stack, FROM_MALLOC);
DTLS_on_libc_memalign(res, size);
return res;
}
#endif // SANITIZER_INTERCEPT_MEMALIGN
#if SANITIZER_INTERCEPT_ALIGNED_ALLOC
INTERCEPTOR(void*, aligned_alloc, uptr boundary, uptr size) {
GET_STACK_TRACE_MALLOC;
return asan_aligned_alloc(boundary, size, &stack);
}
#endif // SANITIZER_INTERCEPT_ALIGNED_ALLOC
INTERCEPTOR(uptr, malloc_usable_size, void *ptr) {
GET_CURRENT_PC_BP_SP;
(void)sp;
return asan_malloc_usable_size(ptr, pc, bp);
}
#if SANITIZER_INTERCEPT_MALLOPT_AND_MALLINFO
// We avoid including malloc.h for portability reasons.
// man mallinfo says the fields are "long", but the implementation uses int.
// It doesn't matter much -- we just need to make sure that the libc's mallinfo
// is not called.
struct fake_mallinfo {
int x[10];
};
INTERCEPTOR(struct fake_mallinfo, mallinfo, void) {
struct fake_mallinfo res;
REAL(memset)(&res, 0, sizeof(res));
return res;
}
INTERCEPTOR(int, mallopt, int cmd, int value) {
return -1;
}
#endif // SANITIZER_INTERCEPT_MALLOPT_AND_MALLINFO
INTERCEPTOR(int, posix_memalign, void **memptr, uptr alignment, uptr size) {
if (UNLIKELY(UseLocalPool()))
return PosixMemalignFromLocalPool(memptr, alignment, size);
GET_STACK_TRACE_MALLOC;
return asan_posix_memalign(memptr, alignment, size, &stack);
}
INTERCEPTOR(void*, valloc, uptr size) {
GET_STACK_TRACE_MALLOC;
return asan_valloc(size, &stack);
}
#if SANITIZER_INTERCEPT_PVALLOC
INTERCEPTOR(void*, pvalloc, uptr size) {
GET_STACK_TRACE_MALLOC;
return asan_pvalloc(size, &stack);
}
#endif // SANITIZER_INTERCEPT_PVALLOC
INTERCEPTOR(void, malloc_stats, void) {
__asan_print_accumulated_stats();
}
#if SANITIZER_ANDROID
// Format of __libc_malloc_dispatch has changed in Android L.
// While we are moving towards a solution that does not depend on bionic
// internals, here is something to support both K* and L releases.
struct MallocDebugK {
void *(*malloc)(uptr bytes);
void (*free)(void *mem);
void *(*calloc)(uptr n_elements, uptr elem_size);
void *(*realloc)(void *oldMem, uptr bytes);
void *(*memalign)(uptr alignment, uptr bytes);
uptr (*malloc_usable_size)(void *mem);
};
struct MallocDebugL {
void *(*calloc)(uptr n_elements, uptr elem_size);
void (*free)(void *mem);
fake_mallinfo (*mallinfo)(void);
void *(*malloc)(uptr bytes);
uptr (*malloc_usable_size)(void *mem);
void *(*memalign)(uptr alignment, uptr bytes);
int (*posix_memalign)(void **memptr, uptr alignment, uptr size);
void* (*pvalloc)(uptr size);
void *(*realloc)(void *oldMem, uptr bytes);
void* (*valloc)(uptr size);
};
ALIGNED(32) const MallocDebugK asan_malloc_dispatch_k = {
WRAP(malloc), WRAP(free), WRAP(calloc),
WRAP(realloc), WRAP(memalign), WRAP(malloc_usable_size)};
ALIGNED(32) const MallocDebugL asan_malloc_dispatch_l = {
WRAP(calloc), WRAP(free), WRAP(mallinfo),
WRAP(malloc), WRAP(malloc_usable_size), WRAP(memalign),
WRAP(posix_memalign), WRAP(pvalloc), WRAP(realloc),
WRAP(valloc)};
namespace __asan {
void ReplaceSystemMalloc() {
void **__libc_malloc_dispatch_p =
(void **)AsanDlSymNext("__libc_malloc_dispatch");
if (__libc_malloc_dispatch_p) {
// Decide on K vs L dispatch format by the presence of
// __libc_malloc_default_dispatch export in libc.
void *default_dispatch_p = AsanDlSymNext("__libc_malloc_default_dispatch");
if (default_dispatch_p)
*__libc_malloc_dispatch_p = (void *)&asan_malloc_dispatch_k;
else
*__libc_malloc_dispatch_p = (void *)&asan_malloc_dispatch_l;
}
}
} // namespace __asan
#else // SANITIZER_ANDROID
namespace __asan {
void ReplaceSystemMalloc() {
}
} // namespace __asan
#endif // SANITIZER_ANDROID
#endif // SANITIZER_FREEBSD || SANITIZER_FUCHSIA || SANITIZER_LINUX ||
// SANITIZER_NETBSD || SANITIZER_SOLARIS