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Fix allocation bug if compiled with modern clang or gcc

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* Add overflow checked intrinsic abstractions that check on overflow.
* Use them for memory allocation code.
* Use size_t type for memory allocation code to support full platform dependent width.

Fixes #3756.
This commit is contained in:
est31
2016-02-19 07:13:16 +01:00
parent 6a25a647b7
commit fb1e52f4d8
3 changed files with 78 additions and 14 deletions
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35
core/vector.h
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@@ -68,11 +68,26 @@ class Vector {
return reinterpret_cast<T*>(_ptr);
}
_FORCE_INLINE_ int _get_alloc_size(int p_elements) const {
return nearest_power_of_2(p_elements*sizeof(T)+sizeof(SafeRefCount)+sizeof(int));
}
_FORCE_INLINE_ size_t _get_alloc_size(size_t p_elements) const {
return nearest_power_of_2_templated(p_elements*sizeof(T)+sizeof(SafeRefCount)+sizeof(int));
}
_FORCE_INLINE_ bool _get_alloc_size_checked(size_t p_elements, size_t *out) const {
#if defined(_add_overflow) && defined(_mul_overflow)
size_t o;
size_t p;
if (_mul_overflow(p_elements, sizeof(T), &o)) return false;
if (_add_overflow(o, sizeof(SafeRefCount)+sizeof(int), &p)) return false;
*out = nearest_power_of_2_templated(p);
return true;
#else
// Speed is more important than correctness here, do the operations unchecked
// and hope the best
*out = _get_alloc_size(p_elements);
return true;
#endif
}
void _unref(void *p_data);
@@ -257,19 +272,21 @@ Error Vector<T>::resize(int p_size) {
// possibly changing size, copy on write
_copy_on_write();
size_t alloc_size;
ERR_FAIL_COND_V(!_get_alloc_size_checked(p_size, &alloc_size), ERR_OUT_OF_MEMORY);
if (p_size>size()) {
if (size()==0) {
// alloc from scratch
void* ptr=memalloc(_get_alloc_size(p_size));
void* ptr=memalloc(alloc_size);
ERR_FAIL_COND_V( !ptr ,ERR_OUT_OF_MEMORY);
_ptr=(T*)((uint8_t*)ptr+sizeof(int)+sizeof(SafeRefCount));
_get_refcount()->init(); // init refcount
*_get_size()=0; // init size (currently, none)
} else {
void *_ptrnew = (T*)memrealloc((uint8_t*)_ptr-sizeof(int)-sizeof(SafeRefCount),_get_alloc_size(p_size));
void *_ptrnew = (T*)memrealloc((uint8_t*)_ptr-sizeof(int)-sizeof(SafeRefCount), alloc_size);
ERR_FAIL_COND_V( !_ptrnew ,ERR_OUT_OF_MEMORY);
_ptr=(T*)((uint8_t*)_ptrnew+sizeof(int)+sizeof(SafeRefCount));
}
@@ -293,7 +310,7 @@ Error Vector<T>::resize(int p_size) {
t->~T();
}
void *_ptrnew = (T*)memrealloc((uint8_t*)_ptr-sizeof(int)-sizeof(SafeRefCount),_get_alloc_size(p_size));
void *_ptrnew = (T*)memrealloc((uint8_t*)_ptr-sizeof(int)-sizeof(SafeRefCount), alloc_size);
ERR_FAIL_COND_V( !_ptrnew ,ERR_OUT_OF_MEMORY);
_ptr=(T*)((uint8_t*)_ptrnew+sizeof(int)+sizeof(SafeRefCount));