pyr0ball
27174a1c79
Diagnosed and fixed the crash that killed HAVOC_NOCD.EXE ~1s after launch
(dgVoodoo window appears black, then the process exits). It was not a clean
exit: an ACCESS_VIOLATION (null-pointer read at VA 0x444E6A) during init.
Root cause is a copy-protection check in the WORLDS\ data-file loader
(0x42a480). It opens each file (GRAFIX/LAND/MAP/STUF) from both a local
"WORLDS\<name>" path and a CD-drive path (HAVOC.INI [SETUP] DRIVE=D:\), and
returns a valid stream only when the local open fails and the CD-drive open
succeeds. With files present locally and no D: drive it returned NULL, and the
GRAFIX loader (0x444db0) dereferenced that NULL without checking.
Fix: 14-byte patch at FO 0x29a2b rewrites the return decision to hand back the
successfully-opened local object. The game now boots to the title screen
("HAVOC(tm) by Reality Bytes"), responsive, main loop running.
- docs/PATCHES.md: full patch table (28 patches) + crash write-up
- tools/: RE + patching scripts (r2pipe disasm, minidump parser, ctypes
debugger, PE/IAT/import analysis)
- run_probe.bat / run_and_log.bat: reliable native launch for repro
- .gitignore: exclude CD images, Ghidra install/project, dgVoodoo, *.ini
Diagnosed via WER minidumps (%LOCALAPPDATA%\CrashDumps) parsed in pure Python
(no cdb/windbg available).
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01TN4Ytn3gdWRonNmHpisWQv
59 lines
2.4 KiB
Python
59 lines
2.4 KiB
Python
import struct, sys, io
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sys.stdout = io.TextIOWrapper(sys.stdout.buffer, encoding='utf-8', errors='replace')
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data = open('HAVOC_NOCD.EXE','rb').read()
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FO2VA = lambda fo: fo + 0x400C00
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VA2FO = lambda va: va - 0x400C00
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def show(start, length, label=''):
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if label: print("=== %s ===" % label)
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for row in range(start, start + length, 16):
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chunk = data[row:row+16]
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ann = []
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for j in range(len(chunk)):
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f = row + j
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try:
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if data[f] == 0xe8 and f+5 <= len(data):
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rel = struct.unpack_from('<i', data, f+1)[0]
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tgt = (FO2VA(f+5) + rel) & 0xFFFFFFFF
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ann.append('+%d:CALL_0x%x' % (j, tgt))
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if data[f] == 0xff and data[f+1] == 0x15 and f+6 <= len(data):
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iat = struct.unpack_from('<I', data, f+2)[0]
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ann.append('+%d:[iat_0x%x]' % (j, iat))
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if data[f] == 0xa3 and f+5 <= len(data):
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va = struct.unpack_from('<I', data, f+1)[0]
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if 0x47C000 <= va <= 0x482000:
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ann.append('+%d:MOV[0x%x],EAX' % (j, va))
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if data[f] == 0xc3: ann.append('+%d:RET' % j)
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if data[f] == 0xc2 and f+3 <= len(data):
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n = struct.unpack_from('<H', data, f+1)[0]
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ann.append('+%d:RET%d' % (j, n))
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except Exception:
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pass
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line = 'FO 0x%05x VA 0x%07x: %s' % (row, FO2VA(row), ' '.join('%02x' % b for b in chunk))
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if ann:
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line += ' [%s]' % ','.join(ann)
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print(line)
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# 0x464DCA - called from entry point
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show(VA2FO(0x464DCA), 80, "0x464DCA (CRT init?)")
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print()
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# 0x465BD3 - called next
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show(VA2FO(0x465BD3), 96, "0x465BD3 (global ctors?)")
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print()
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# 0x465BC8 - called next
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show(VA2FO(0x465BC8), 32, "0x465BC8")
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print()
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# Check IAT entries near 0x482434 and 0x48243c
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print("=== IAT around 0x482430 ===")
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for va_iat in range(0x482430, 0x482470, 4):
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fo = va_iat - 0x47C000 + 0x69400 # .data section
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if fo < 0 or fo+4 > len(data): continue
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val = struct.unpack_from('<I', data, fo)[0]
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# Look for the import name by checking .idata
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# .idata: VA 0x00482000, rawoff=0x6ec00 rawsiz=0x00e00
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fo_idata = 0x6ec00 + (va_iat - 0x482000)
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print(" [0x%x] = 0x%08x" % (va_iat, val))
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# Also look at function 0x464F67 (called in alloc chain) to understand what
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# the heap needs
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show(VA2FO(0x464F67), 48, "0x464F67 (alloc helper 2)")
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