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[Memory] Fix Protect range calculation

This commit is contained in:
Triang3l 2020-09-01 12:44:37 +03:00
parent 1e9ee8f43b
commit 52efbcf741
1 changed files with 32 additions and 5 deletions
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37
src/xenia/memory.cc
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@ -1145,12 +1145,38 @@ bool BaseHeap::Release(uint32_t base_address, uint32_t* out_region_size) {
bool BaseHeap::Protect(uint32_t address, uint32_t size, uint32_t protect,
uint32_t* old_protect) {
uint32_t page_count = xe::round_up(size, page_size_) / page_size_;
if (!size) {
XELOGE("BaseHeap::Protect failed due to zero size");
return false;
}
// From the VirtualProtect MSDN page:
//
// "The region of affected pages includes all pages containing one or more
// bytes in the range from the lpAddress parameter to (lpAddress+dwSize).
// This means that a 2-byte range straddling a page boundary causes the
// protection attributes of both pages to be changed."
//
// "The access protection value can be set only on committed pages. If the
// state of any page in the specified region is not committed, the function
// fails and returns without modifying the access protection of any pages in
// the specified region."
uint32_t start_page_number = (address - heap_base_) / page_size_;
uint32_t end_page_number = start_page_number + page_count - 1;
start_page_number =
std::min(uint32_t(page_table_.size()) - 1, start_page_number);
end_page_number = std::min(uint32_t(page_table_.size()) - 1, end_page_number);
if (start_page_number >= page_table_.size()) {
XELOGE("BaseHeap::Protect failed due to out-of-bounds base address {:08X}",
address);
return false;
}
uint32_t end_page_number =
uint32_t((uint64_t(address) + size - 1 - heap_base_) / page_size_);
if (end_page_number >= page_table_.size()) {
XELOGE(
"BaseHeap::Protect failed due to out-of-bounds range ({:08X} bytes "
"from {:08x})",
size, address);
return false;
}
auto global_lock = global_critical_region_.Acquire();
@ -1173,6 +1199,7 @@ bool BaseHeap::Protect(uint32_t address, uint32_t size, uint32_t protect,
// Attempt host change (hopefully won't fail).
// We can only do this if our size matches system page granularity.
uint32_t page_count = end_page_number - start_page_number + 1;
if (page_size_ == xe::memory::page_size() ||
(((page_count * page_size_) % xe::memory::page_size() == 0) &&
((start_page_number * page_size_) % xe::memory::page_size() == 0))) {