# gdb script: trace the path through FUN_0042aec0 (GPU arch/config init) by # attaching to a running cdt at the CDT_PAUSE (bpz18 variant). # # Host: c48=6 c4c=0x27 c50=7 c54=5 e94=0x18. Guest reaches same c48..c54 but # e94=0, so some branch inside FUN_0042aec0 diverges. This logs hits on: # 0x32aec0 FUN_0042aec0 entry # 0x32b0b7 after chip-info store # 0x32c911 the 0xc4c dispatch # 0x32e8be case index 1 body (sets e94=0x18) # 0x32e46a default target of the dispatch # 0x2e3e80 FUN_003e3e80 (terminator; dumps ds fields) import gdb import time gdb.execute("set pagination off") gdb.execute("set confirm off") out = gdb.execute("info proc mappings", to_string=True) base = None for line in out.splitlines(): if "libcuda" in line and "r-xp" in line: f = line.split() base = int(f[0], 16) - int(f[3], 16) break print("BASE=0x%x" % (base or 0)) if base is None: raise SystemExit SITES = [ (0x32aec0, "F42AEC0_ENTRY"), (0x32b0b7, "AFTER_CHIPINFO"), (0x32c911, "C4C_DISPATCH"), (0x32e8be, "CASE1_e94_0x18"), (0x32e46a, "DISPATCH_DEFAULT"), ] for off, name in SITES: gdb.execute("break *0x%x" % (base + off)) CALLER_RET = base + 0xd0eae1 gdb.execute("break *0x%x" % (base + 0x2e3e80)) def rd(addr, n=4, fmt="unsigned int"): try: return int(gdb.parse_and_eval("*(%s*)0x%x" % (fmt, addr))) & ((1 << (8 * n)) - 1) except Exception: return None t0 = time.time() for hit in range(120): try: gdb.execute("continue") except gdb.error as e: print("CONTINUE_END %s" % e) break rip = int(gdb.parse_and_eval("$rip")) & 0xffffffffffffffff off = rip - base if off == 0x2e3e80: ret = rd(int(gdb.parse_and_eval("$rsp")), 8, "unsigned long") if ret != CALLER_RET: continue rdi = int(gdb.parse_and_eval("$rdi")) & 0xffffffffffffffff ds = rd(rdi + 0x40, 8, "unsigned long") print("TERMINATOR FUN_003e3e80 dev=0x%x ds=0x%x t=%.3f" % (rdi, ds or 0, time.time() - t0)) for o in [0xc48, 0xc4c, 0xc50, 0xc54, 0xe94, 0x4354, 0x426c]: print(" ds+0x%x = 0x%x" % (o, rd(ds + o) or 0)) break name = dict((o, n) for o, n in SITES).get(off, "?") rcx = int(gdb.parse_and_eval("$rcx")) & 0xffffffffffffffff eax = rd("$eax") if False else (int(gdb.parse_and_eval("$eax")) & 0xffffffff) extra = "" if off == 0x32c911: extra = " c4c=0x%x arch=0x%x" % (rd(rcx + 0xc4c) or 0, rd(rcx + 0xc50) or 0) print("HIT t=%.3f +0x%x %s eax=0x%x rcx=0x%x%s" % (time.time() - t0, off, name, eax, rcx, extra)) try: gdb.execute("detach") except Exception: pass