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| -rw-r--r-- | tools/guest-diag/wall2/README-session77.md | 28 | ||||
| -rw-r--r-- | tools/guest-diag/wall2/t104.py | 56 |
2 files changed, 84 insertions, 0 deletions
diff --git a/tools/guest-diag/wall2/README-session77.md b/tools/guest-diag/wall2/README-session77.md index 03b0099..2fd77a6 100644 --- a/tools/guest-diag/wall2/README-session77.md +++ b/tools/guest-diag/wall2/README-session77.md @@ -605,3 +605,31 @@ timeout fire while a tracee is at a frequent-firing BP; prefer BPs that fire once or self-disable; prefer no-ptrace pollers for anything with a repeating pattern; the safe diagnostic is attach -> read -> detach without continue. + +**15. Session 94: THE INSTANCE CLEARS ARE REQUIRED (zero-gdb disproved); t104 is the safe form.** +Pure zero-gdb run (fresh r694, client + unwait.py ONLY, no gdb): unwait +wrote three +0x80 words and the client still ended `VKFAIL vkCreateDevice +... -4` - WITHOUT the instance-phase marker clears the device gate fails +even with the words. With t104.py (single BP at +0xB33D30; clears +u16@+0xe/+0xc/u32@+0; self-exits on cleared>=8 OR chits>=40 OR 25 s since +the last clear -> returns True so the script tail runs and batch gdb exits +cleanly, no outer-timeout dependence) + unwait + live_walk: CLEAR#1..#5, +two words written, client reached `VKINSTANCE ok / VKDEVS 2 / VKPICK / +VKDEVICE ok family=0` (r694 client 3725). The client then sat in the +post-device wait again; the t102 diagnostic could not attach because the +t104 gdb still held the slot (its 25 s-idle exit never fired - no +post-instance B33D30 hits - and its 150 s timeout likely fired at a stop += the known wedge risk). NEXT FORM: make t104 detach ITSELF from inside +the handler once the clears are done (`gdb.execute("detach")` from the +stop handler; the tracee resumes; the script ends and gdb exits) so NO +gdb is ever held while the client runs - then t102 always has the slot +and the wedge class disappears end-to-end. + +**16. The allocation/post-device phase is the remaining gate.** With +VKDEVICE green the client waits in a site that is neither the +0x80 word +pattern nor (likely) the A8 count path; the next session should (a) get +the detach-first t104 live, (b) run t102 immediately after VKDEVICE to +name the wait (read PC/bt/A8 count = base+0x2070b7c), and (c) inspect the +service for this client (pushes decoded / releases applied / counter +pub_calls) to see whether the allocation needs the live injections only +or a service-side gap. diff --git a/tools/guest-diag/wall2/t104.py b/tools/guest-diag/wall2/t104.py new file mode 100644 index 0000000..5a4c059 --- /dev/null +++ b/tools/guest-diag/wall2/t104.py @@ -0,0 +1,56 @@ +import gdb, time +gr = gdb.execute +inf = gdb.selected_inferior() +pid = inf.pid +base = None +for line in open("/proc/%d/maps" % pid): + parts = line.split() + try: + lo, hi = [int(x,16) for x in parts[0].split('-')] + except Exception: + continue + if base is None and "libnvidia-eglcore" in line and int(parts[2],16) == 0: + base = lo +print("BASE 0x%x PID %d" % (base or 0, pid), flush=True) +def u64(a): return int(gdb.parse_and_eval("*(unsigned long*)0x%x" % a)) +def u32(a): return int(gdb.parse_and_eval("*(unsigned int*)0x%x" % a)) +state = {"chits":0, "cleared":0, "t0":time.time(), "last":time.time()} +class BC(gdb.Breakpoint): + def __init__(self): + super().__init__("*0x%x" % (base + 0xB33D30), internal=False) + self.silent = True + def stop(self): + state["chits"] += 1 + try: + obj = int(gdb.parse_and_eval("$rdi")) + n = int(gdb.parse_and_eval("$rsi")) + cnt = u32(obj + 0x22efc) + for i in range(0, min(cnt, 32)): + p = u64(obj + 0x1428 + i*8) + if not p: + continue + tgt = p + n * 0x10 + try: + v16 = int(gdb.parse_and_eval("*(unsigned short*)0x%x" % (tgt + 0xe))) + if v16 == 0xffff: + gr("set {unsigned short}0x%x = 0" % (tgt + 0xe)) + gr("set {unsigned int}0x%x = 0" % tgt) + gr("set {unsigned short}0x%x = 0" % (tgt + 0xc)) + state["cleared"] += 1 + state["last"] = time.time() + print("CLEAR#%d obj=0x%x n=0x%x tgt=0x%x" % (state["cleared"], obj, n, tgt), flush=True) + except Exception: + pass + except Exception: + pass + if state["cleared"] >= 8 or state["chits"] >= 40 or (time.time() - state["last"]) > 25.0: + self.enabled = False + print("BC-EXIT cleaned=%d chits=%d" % (state["cleared"], state["chits"]), flush=True) + return True + return False +try: + BC(); print("BPS-SET", flush=True) + gr("continue") +except Exception as e: + print("bpfail %s" % e, flush=True) +print("T104-DONE chits=%d cleared=%d" % (state["chits"], state["cleared"]), flush=True) |