t3hn3rd
8b4335768b
PMM Rewrite:
- Replace ~8KB record array with compact bitmaps
(PhysPresent/PhysAlloc/PhysScanned, 128B each)
- Add PhysOwner[0..1023] for per-block ownership tracking
- new_block: O(1) amortised via NextFreeHint + dword-level BSF scan,
returns 0 as OOM sentinel
- free_block: O(1) direct bit clear with double-free detection
- alloc_block: validates PhysPresent and PhysAlloc bits before allocation
- Add pmm_free_blocks/pmm_total_blocks stats functions
VMM Correctness Fixes:
- Fix free_page block extraction (Address SHR 10, was using
raw Address field)
- Fix invlpg operand (use virtual address, was passing PDE index)
- Clear PDE entry on free_page before returning block to PMM
- Remove map_page double-write (delegate to map_page_ex only)
- Add OOM propagation (new_page returns false if PMM returns 0)
- Fix missing pop_trace in new_page error path
LMM Rewrite:
- Replace per-entry record array with bitmap allocator
(93% vs 43% page efficiency)
- Layout: Header(24B) + Bitmap(64512B) + Padding + Data at 0x10000
- SIZE_PREFIX=16 for 16-byte aligned returns (SSE MOVAPS requirement)
- Next-fit bitmap scan with roving hint (NextFree) and dword-level
fast skip
- Large alloc sentinel (LARGE_ALLOC_MAGIC=$FFFFFFFE) so kfree detects
klalloc'd memory
- Implement klfree (was previously a no-op - pages could never
be returned)
- Implement try_release_page (return fully-free heap pages to VMM/PMM)
- Fix interrupt safety: stack-balanced pushfd/cli/pop +
restore_if (sti only)
Fixes Bad TSS caused by popfd restoring dangerous EFLAGS bits (NT, IOPL)
- Zero memory via rep stosd instead of byte-by-byte loop
Hardening:
- kalloc OOM now triggers BSOD instead of returning nil
(90% of callers don't check)
- Double-free detection in kfree (verify bitmap bits set before clearing)
- Guard bytes ({$IFDEF DEBUG_LMM}): $DEADBEEF sentinel for buffer overrun detection
- kpalloc: bounds check (block >= 1024 -> GPF) + syslog MMIO mapping audit log
Observability:
- Add MEMINFO command as src/prog/meminfo.pas (moved from inline kernel.pas)
- Displays multiboot memory, PMM block stats, LMM heap stats
- Register via progmanager.pas following standard prog pattern
Files changed:
- src/pmemorymanager.pas
- src/vmemorymanager.pas
- src/lmemorymanager.pas
- src/kernel.pas
- src/progmanager.pas
- src/prog/meminfo.pas