Re: panic: vm_object_madvise: page 0xfffffe0413c58630 is fictitious

On 27.11.2012 16:40, Andriy Gapon wrote:
> on 27/11/2012 17:38 Andre Oppermann said the following:
>> Clang doing a manual kernel build of my work tree with "make -j8 kernel".
>
> This sounds like a "process" that may have triggered the problem.
> But is it the process that made the syscall in the backtrace?
> You can check by e.g. going to frame 13 and examining *td and *td->td_proc.
>

(kgdb) frame 13
#13 0xffffffff80bfd3a5 in amd64_syscall (td=0xfffffe0018230000, traced=0) at subr_syscall.c:135
135                     error = (sa->callp->sy_call)(td, sa->args);
Current language:  auto; currently minimal
(kgdb) p *td
$1 = {td_lock = 0xffffffff812ac180, td_proc = 0xfffffe0256301950, td_plist = {tqe_next = 0x0,
     tqe_prev = 0xfffffe0256301960}, td_runq = {tqe_next = 0x0, tqe_prev = 0xffffffff812ac630},
   td_slpq = {tqe_next = 0x0, tqe_prev = 0xfffffe00181c6a80}, td_lockq = {tqe_next = 0x0,
     tqe_prev = 0xffffff8487efc540}, td_hash = {le_next = 0x0, le_prev = 0xffffff80006ffe58},
   td_cpuset = 0xfffffe0007376dc8, td_sel = 0x0, td_sleepqueue = 0xfffffe00181c6a80,
   td_turnstile = 0xfffffe0018378b40, td_rlqe = 0xfffffe0018215a00, td_umtxq = 0xfffffe0018170580,
   td_tid = 100299, td_sigqueue = {sq_signals = {__bits = {0, 0, 0, 0}}, sq_kill = {__bits = {0, 0,
         0, 0}}, sq_list = {tqh_first = 0x0, tqh_last = 0xfffffe00182300b8},
     sq_proc = 0xfffffe0256301950, sq_flags = 1}, td_lend_user_pri = 255 'ÿ', td_flags = 4,
   td_inhibitors = 0, td_pflags = 0, td_dupfd = 0, td_sqqueue = 0, td_wchan = 0x0, td_wmesg = 0x0,
   td_lastcpu = 0 '\0', td_oncpu = 0 '\0', td_owepreempt = 0 '\0', td_tsqueue = 255 'ÿ',
   td_locks = 3, td_rw_rlocks = 0, td_lk_slocks = 0, td_stopsched = 1, td_blocked = 0x0,
   td_lockname = 0x0, td_contested = {lh_first = 0x0}, td_sleeplocks = 0xffffffff81429ea0,
   td_intr_nesting_level = 0, td_pinned = 1, td_ucred = 0xfffffe0018244c00, td_estcpu = 0,
   td_slptick = 0, td_blktick = 0, td_swvoltick = 2312563, td_cow = 6, td_ru = {ru_utime = {
       tv_sec = 0, tv_usec = 0}, ru_stime = {tv_sec = 0, tv_usec = 0}, ru_maxrss = 50728,
     ru_ixrss = 2858440, ru_idrss = 31280, ru_isrss = 26752, ru_minflt = 7722, ru_majflt = 11,
     ru_nswap = 0, ru_inblock = 8, ru_oublock = 4, ru_msgsnd = 0, ru_msgrcv = 0, ru_nsignals = 0,
     ru_nvcsw = 35, ru_nivcsw = 98}, td_rux = {rux_runtime = 0, rux_uticks = 0, rux_sticks = 0,
     rux_iticks = 0, rux_uu = 0, rux_su = 0, rux_tu = 0}, td_incruntime = 2792408043,
   td_runtime = 2792408043, td_pticks = 0, td_sticks = 7, td_iticks = 0, td_uticks = 108,
   td_intrval = 0, td_oldsigmask = {__bits = {0, 0, 0, 0}}, td_generation = 133, td_sigstk = {
     ss_sp = 0x0, ss_size = 0, ss_flags = 4}, td_xsig = 0, td_profil_addr = 0, td_profil_ticks = 0,
   td_name = "cc", '\0' <repeats 17 times>, td_fpop = 0x0, td_dbgflags = 0, td_dbgksi = {
     ksi_link = {tqe_next = 0x0, tqe_prev = 0x0}, ksi_info = {si_signo = 0, si_errno = 0,
       si_code = 0, si_pid = 0, si_uid = 0, si_status = 0, si_addr = 0x0, si_value = {
         sival_int = 0, sival_ptr = 0x0, sigval_int = 0, sigval_ptr = 0x0}, _reason = {_fault = {
           _trapno = 0}, _timer = {_timerid = 0, _overrun = 0}, _mesgq = {_mqd = 0}, _poll = {
           _band = 0}, __spare__ = {__spare1__ = 0, __spare2__ = {0, 0, 0, 0, 0, 0, 0}}}},
     ksi_flags = 0, ksi_sigq = 0x0}, td_ng_outbound = 0, td_osd = {osd_nslots = 0, osd_slots = 0x0,
     osd_next = {le_next = 0x0, le_prev = 0x0}}, td_map_def_user = 0x0, td_dbg_forked = 0,
   td_vp_reserv = 0, td_sigmask = {__bits = {0, 0, 0, 0}}, td_rqindex = 0 '\0',
   td_base_pri = 175 '¯', td_priority = 175 '¯', td_pri_class = 3 '\003', td_user_pri = 175 '¯',
   td_base_user_pri = 175 '¯', td_pcb = 0xffffff8487f47cc0, td_state = TDS_RUNNING, td_retval = {0,
     5}, td_slpcallout = {c_links = {sle = {sle_next = 0x0}, tqe = {tqe_next = 0x0,
         tqe_prev = 0x0}}, c_time = 0, c_arg = 0x0, c_func = 0, c_lock = 0x0, c_flags = 16,
     c_cpu = 0}, td_frame = 0xffffff8487f47c00, td_kstack_obj = 0xfffffe0256092570,
   td_kstack = 18446743543414538240, td_kstack_pages = 4, td_critnest = 1, td_md = {
     md_spinlock_count = 1, md_saved_flags = 582, md_spurflt_addr = 34407014400},
   td_sched = 0xfffffe0018230458, td_ar = 0x0, td_lprof = {{lh_first = 0x0}, {lh_first = 0x0}},
   td_dtrace = 0xfffffe0248e8c000, td_errno = 0, td_vnet = 0x0, td_vnet_lpush = 0x0,
   td_intr_frame = 0x0, td_rfppwait_p = 0xfffffe0248f8a950, td_ma = 0x0, td_ma_cnt = 0}
(kgdb) p *td->td_proc
$2 = {p_list = {le_next = 0xfffffe0248f8a950, le_prev = 0xfffffe0248eb04a8}, p_threads = {
     tqh_first = 0xfffffe0018230000, tqh_last = 0xfffffe0018230010}, p_slock = {lock_object = {
       lo_name = 0xffffffff80e5c3a8 "process slock", lo_flags = 720896, lo_data = 0,
       lo_witness = 0x0}, mtx_lock = 4}, p_ucred = 0xfffffe0018244c00, p_fd = 0xfffffe0018560000,
   p_fdtol = 0x0, p_stats = 0xfffffe0018225a00, p_limit = 0xfffffe0018468900, p_limco = {c_links = {
       sle = {sle_next = 0x0}, tqe = {tqe_next = 0x0, tqe_prev = 0x0}}, c_time = 0, c_arg = 0x0,
     c_func = 0, c_lock = 0xfffffe0256301a48, c_flags = 0, c_cpu = 0},
   p_sigacts = 0xfffffe0256372000, p_flag = 268451842, p_state = PRS_NORMAL, p_pid = 5732,
   p_hash = {le_next = 0x0, le_prev = 0xffffff80006ed320}, p_pglist = {
     le_next = 0xfffffe0248d5f000, le_prev = 0xfffffe0248f8aa18}, p_pptr = 0xfffffe0248f8a950,
   p_sibling = {le_next = 0x0, le_prev = 0xfffffe0248f8aa40}, p_children = {lh_first = 0x0},
   p_mtx = {lock_object = {lo_name = 0xffffffff80e5c39b "process lock", lo_flags = 21168128,
       lo_data = 0, lo_witness = 0xffffff80006c8400}, mtx_lock = 4}, p_ksi = 0xfffffe0016c82850,
   p_sigqueue = {sq_signals = {__bits = {0, 0, 0, 0}}, sq_kill = {__bits = {0, 0, 0, 0}},
     sq_list = {tqh_first = 0x0, tqh_last = 0xfffffe0256301a90}, sq_proc = 0xfffffe0256301950,
     sq_flags = 1}, p_oppid = 0, p_vmspace = 0xfffffe0018260188, p_swtick = 2311559, p_realtimer = {
     it_interval = {tv_sec = 0, tv_usec = 0}, it_value = {tv_sec = 0, tv_usec = 0}}, p_ru = {
     ru_utime = {tv_sec = 0, tv_usec = 0}, ru_stime = {tv_sec = 0, tv_usec = 0}, ru_maxrss = 0,
     ru_ixrss = 0, ru_idrss = 0, ru_isrss = 0, ru_minflt = 0, ru_majflt = 0, ru_nswap = 0,
     ru_inblock = 0, ru_oublock = 0, ru_msgsnd = 0, ru_msgrcv = 0, ru_nsignals = 0, ru_nvcsw = 0,
     ru_nivcsw = 0}, p_rux = {rux_runtime = 0, rux_uticks = 0, rux_sticks = 0, rux_iticks = 0,
     rux_uu = 0, rux_su = 0, rux_tu = 0}, p_crux = {rux_runtime = 0, rux_uticks = 0,
     rux_sticks = 0, rux_iticks = 0, rux_uu = 0, rux_su = 0, rux_tu = 0}, p_profthreads = 0,
   p_exitthreads = 0, p_traceflag = 0, p_tracevp = 0x0, p_tracecred = 0x0,
   p_textvp = 0xfffffe0248d4f5d0, p_lock = 0, p_sigiolst = {slh_first = 0x0}, p_sigparent = 20,
   p_sig = 0, p_code = 0, p_stops = 0, p_stype = 0, p_step = 0 '\0', p_pfsflags = 0 '\0',
   p_nlminfo = 0x0, p_aioinfo = 0x0, p_singlethread = 0x0, p_suspcount = 0, p_xthread = 0x0,
   p_boundary_count = 0, p_pendingcnt = 0, p_itimers = 0x0, p_procdesc = 0x0, p_magic = 3203398350,
   p_osrel = 1000025, p_comm = "cc", '\0' <repeats 17 times>, p_pgrp = 0xfffffe00184e5900,
   p_sysent = 0xffffffff8123bf58, p_args = 0x0, p_cpulimit = 9223372036854775807, p_nice = 0 '\0',
   p_fibnum = 0, p_xstat = 0, p_klist = {kl_list = {slh_first = 0x0},
     kl_lock = 0xffffffff80849790 <knlist_mtx_lock>,
     kl_unlock = 0xffffffff808497b0 <knlist_mtx_unlock>,
     kl_assert_locked = 0xffffffff808497d0 <knlist_mtx_assert_locked>,
     kl_assert_unlocked = 0xffffffff808497f0 <knlist_mtx_assert_unlocked>,
     kl_lockarg = 0xfffffe0256301a48}, p_numthreads = 1, p_md = {md_ldt = 0x0, md_ldt_sd = {
       sd_lolimit = 0, sd_lobase = 0, sd_type = 0, sd_dpl = 0, sd_p = 0, sd_hilimit = 0,
       sd_xx0 = 0, sd_gran = 0, sd_hibase = 0, sd_xx1 = 0, sd_mbz = 0, sd_xx2 = 0}}, p_itcallout = {
     c_links = {sle = {sle_next = 0x0}, tqe = {tqe_next = 0x0, tqe_prev = 0x0}}, c_time = 0,
     c_arg = 0x0, c_func = 0, c_lock = 0x0, c_flags = 16, c_cpu = 0}, p_acflag = 0, p_peers = 0x0,
   p_leader = 0xfffffe0256301950, p_emuldata = 0x0, p_label = 0x0, p_sched = 0xfffffe0256301df8,
   p_ktr = {stqh_first = 0x0, stqh_last = 0xfffffe0256301d88}, p_mqnotifier = {lh_first = 0x0},
   p_dtrace = 0xfffffe0256687a40, p_pwait = {cv_description = 0xffffffff80e5d034 "ppwait",
     cv_waiters = 0}, p_dbgwait = {cv_description = 0xffffffff80e5d03b "dbgwait", cv_waiters = 0},
   p_prev_runtime = 0, p_racct = 0x0, p_throttled = 0 '\0', p_orphan = {le_next = 0x0,
     le_prev = 0x0}, p_orphans = {lh_first = 0x0}}

-- 
Andre