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Stricter checks in MemPool::Allocate().

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This commit is contained in:
mtheall 2015-03-17 13:49:47 -05:00
parent 7a71787670
commit b30f553dd0
1 changed files with 22 additions and 7 deletions
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29
libctru/source/allocator/mem_pool.cpp
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@ -32,18 +32,33 @@ void MemPool::CoalesceRight(MemBlock* b)
bool MemPool::Allocate(MemChunk& chunk, u32 size, int align)
{
int alignM = (1 << align) - 1;
u32 newsize;
newsize = (size + alignM) &~ alignM; // Round the size
if(newsize < size)return false;//Return error when integer-overflow occurs due to aligning the size.
size = newsize;
// Don't shift out of bounds (CERT INT34-C)
if(align >= 32 || align < 0)
return false;
// Alignment must not be 0
if(align == 0)
return false;
u32 alignMask = (1 << align) - 1;
// Check if size doesn't fit neatly in alignment
if(size & alignMask)
{
// Make sure addition won't overflow (CERT INT30-C)
if(size > UINT32_MAX - alignMask)
return false;
// Pad size to next alignment
size = (size + alignMask) &~ alignMask;
}
// Find the first suitable block
for (auto b = first; b; b = b->next)
{
auto addr = b->base;
u32 begWaste = (u32)addr & alignM;
if (begWaste > 0) begWaste = alignM + 1 - begWaste;
u32 begWaste = (u32)addr & alignMask;
if (begWaste > 0) begWaste = alignMask + 1 - begWaste;
addr += begWaste;
u32 bSize = b->size - begWaste;
if (bSize < size) continue;