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[Memory] Add alignment guards to PhysicalHeap allocations

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Add alignment checks and parent release on failure in Alloc, AllocFixed,
and AllocRange to prevent misaligned addresses reaching BaseHeap.

Fixes #954
This commit is contained in:
Herman S.
2026-03-31 18:00:26 +09:00
parent d2c8ca675e
commit 11ad6b0a87
3 changed files with 243 additions and 1 deletions
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31
src/xenia/memory.cc
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@@ -1645,6 +1645,13 @@ void PhysicalHeap::Initialize(Memory* memory, uint8_t* membase,
BaseHeap::Initialize(memory, membase, heap_type, heap_base, heap_size,
page_size, host_address_offset);
parent_heap_ = parent_heap;
// The physical base offset (host_address_offset) must be a multiple of
// page_size. Otherwise, aligned parent allocations become misaligned after
// translation back to virtual addresses (parent_address + heap_base_ -
// GetPhysicalAddress(heap_base_) loses alignment).
xenia_assert(host_address_offset % page_size == 0);
system_page_size_ = uint32_t(xe::memory::page_size());
xenia_assert(xe::is_pow2(system_page_size_));
system_page_shift_ = xe::log2_floor(system_page_size_);
@@ -1685,6 +1692,14 @@ bool PhysicalHeap::Alloc(uint32_t size, uint32_t alignment,
// Given the address we've reserved in the parent heap, pin that here.
// Shouldn't be possible for it to be allocated already.
uint32_t address = heap_base_ + parent_address - parent_heap_start;
if (address % alignment != 0) {
XELOGE(
"PhysicalHeap::Alloc translated address {:08X} misaligned "
"(alignment {:08X}, physical base offset {:08X})",
address, alignment, parent_heap_start);
parent_heap_->Release(parent_address);
return false;
}
if (!BaseHeap::AllocFixed(address, size, alignment, allocation_type,
protect)) {
XELOGE(
@@ -1721,6 +1736,14 @@ bool PhysicalHeap::AllocFixed(uint32_t base_address, uint32_t size,
// Shouldn't be possible for it to be allocated already.
uint32_t address =
heap_base_ + parent_base_address - GetPhysicalAddress(heap_base_);
if (address % alignment != 0) {
XELOGE(
"PhysicalHeap::AllocFixed translated address {:08X} misaligned "
"(alignment {:08X}, physical base offset {:08X})",
address, alignment, GetPhysicalAddress(heap_base_));
parent_heap_->Release(parent_base_address);
return false;
}
if (!BaseHeap::AllocFixed(address, size, alignment, allocation_type,
protect)) {
XELOGE(
@@ -1762,6 +1785,14 @@ bool PhysicalHeap::AllocRange(uint32_t low_address, uint32_t high_address,
// Shouldn't be possible for it to be allocated already.
uint32_t address =
heap_base_ + parent_address - GetPhysicalAddress(heap_base_);
if (address % alignment != 0) {
XELOGE(
"PhysicalHeap::AllocRange translated address {:08X} misaligned "
"(alignment {:08X}, physical base offset {:08X})",
address, alignment, GetPhysicalAddress(heap_base_));
parent_heap_->Release(parent_address);
return false;
}
if (!BaseHeap::AllocFixed(address, size, alignment, allocation_type,
protect)) {
XELOGE(