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
45 lines
1.6 KiB
Python
45 lines
1.6 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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# Show context around the "missing from the HAVOC directory" string
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fo = 0x6bec5
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print("=== Context around FO 0x%05x ===" % fo)
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start = fo - 0x80
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end = fo + 0x80
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chunk = data[start:end]
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for i in range(0, len(chunk), 16):
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row = chunk[i:i+16]
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hex_part = ' '.join('%02x' % b for b in row)
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asc_part = ''.join(chr(b) if 32 <= b < 127 else '.' for b in row)
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print("FO 0x%05x: %-47s %s" % (start+i, hex_part, asc_part))
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print()
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print("=== Callers of 'missing' string at FO 0x6BEC5 VA 0x46CAC5 ===")
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target = 0x46cac5
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for fo2 in range(0x400, 0x67000):
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if data[fo2] == 0x68: # PUSH imm32
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imm = struct.unpack_from('<I', data, fo2+1)[0]
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if imm == target:
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print(" PUSH 0x46CAC5 at FO 0x%05x VA 0x%08x" % (fo2, FO2VA(fo2)))
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# Also look for what calls the string display - search for any CALL near those PUSHes
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print()
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print("=== Reading STRDATA.DAT ===")
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try:
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sd = open('STRDATA.DAT','rb').read()
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print("Size: %d bytes" % len(sd))
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# Try to find "corrupt" in it
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for needle in [b'corrupt', b'unavail', b'Corrupt', b'Unavail']:
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idx = sd.find(needle)
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if idx != -1:
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print("Found '%s' at offset 0x%x: %r" % (needle.decode(), idx, sd[max(0,idx-20):idx+60]))
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# Show first 256 bytes as text
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print("First 200 bytes:")
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printable = ''.join(chr(b) if 32 <= b < 127 else ('\\x%02x' % b) for b in sd[:200])
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print(printable)
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except Exception as e:
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print("Error: %s" % e)
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