AuroraMiddleware/skia2
1
0
Fork 0
Code Issues Pull Requests Projects Releases Wiki Activity

bug fix: take the fAllocSize into account when we perform the compare, otherwise

Browse Source 
we can read past the end of one of the flatdatas if we're unlucky.



git-svn-id: http://skia.googlecode.com/svn/trunk@4503 2bbb7eff-a529-9590-31e7-b0007b416f81
This commit is contained in:
reed@google.com 2012-07-10 13:29:52 +00:00
parent c432f00a84
commit b4ed0178d0
1 changed files with 19 additions and 10 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

29
src/core/SkPictureFlat.h
View File

@ -155,12 +155,12 @@ class SkFlatData {
public:
static int Compare(const SkFlatData* a, const SkFlatData* b) {
size_t bytesToCompare = sizeof(a->fChecksum) + a->fAllocSize;
SkASSERT(SkIsAlign4(bytesToCompare));
size_t bytes = a->bytesToCompare();
SkASSERT(SkIsAlign4(bytes));
const uint32_t* a_ptr = &(a->fChecksum);
const uint32_t* b_ptr = &(b->fChecksum);
const uint32_t* stop = a_ptr + bytesToCompare / sizeof(uint32_t);
const uint32_t* a_ptr = a->dataToCompare();
const uint32_t* b_ptr = b->dataToCompare();
const uint32_t* stop = a_ptr + bytes / sizeof(uint32_t);
while(a_ptr < stop) {
if (*a_ptr != *b_ptr) {
return (*a_ptr < *b_ptr) ? -1 : 1;
@ -172,9 +172,10 @@ public:
}
int index() const { return fIndex; }
void* data() const { return (char*)this + sizeof(*this); }
// We guarantee that our data is 32bit aligned
uint32_t* data32() const { return (uint32_t*)this->data(); }
const void* data() const { return (const char*)this + sizeof(*this); }
void* data() { return (char*)this + sizeof(*this); }
// Our data is always 32bit aligned, so we can offer this accessor
uint32_t* data32() { return (uint32_t*)this->data(); }
#ifdef SK_DEBUG_SIZE
size_t size() const { return sizeof(SkFlatData) + fAllocSize; }
@ -194,9 +195,17 @@ private:
// Data members add-up to 128 bits of storage, so data() is 128-bit
// aligned, which helps performance of memcpy in SkWriter32::flatten
int fIndex;
int32_t fAllocSize;
// fChecksum must be defined last in order to be contiguous with data()
// From here down is the data we look at in the search/sort. We always begin
// with the checksum and then length.
uint32_t fChecksum;
int32_t fAllocSize;
// uint32_t data[]
const uint32_t* dataToCompare() const { return &fChecksum; }
size_t bytesToCompare() const {
return sizeof(fChecksum) + sizeof(fAllocSize) + fAllocSize;
}
};
template <class T>