stable/10 panic

hiren panchasara hiren.panchasara at gmail.com
Tue May 6 23:47:07 UTC 2014


On Tue, May 6, 2014 at 1:34 PM, John Baldwin <jhb at freebsd.org> wrote:
> On Monday, May 05, 2014 2:46:12 pm Sean Bruno wrote:
>> On Mon, 2014-05-05 at 13:48 -0400, John Baldwin wrote:
>> > On Monday, April 21, 2014 12:31:32 pm Sean Bruno wrote:
>> > > We're seeing this *a lot* on our qmail based hosts during our stable/10
>> > > rollout.  We're running stable/10 from around svn rev 261579 (mid
>> > > february) with one or two patches strewn in.
>> > >
>> > > sean
>> > >
>> > >
>> > > GNU gdb 6.1.1 [FreeBSD]
>> > > Copyright 2004 Free Software Foundation, Inc.
>> > > GDB is free software, covered by the GNU General Public License, and you
> are
>> > > welcome to change it and/or distribute copies of it under certain
> conditions.
>> > > Type "show copying" to see the conditions.
>> > > There is absolutely no warranty for GDB.  Type "show warranty" for
> details.
>> > > This GDB was configured as "amd64-marcel-freebsd"...
>> > >
>> > > Unread portion of the kernel message buffer:
>> > > panic: page fault
>> > > cpuid = 5
>> > > KDB: stack backtrace:
>> > > db_trace_self_wrapper() at db_trace_self_wrapper+0x2b/frame
> 0xfffffe048b9b12a0
>> > > kdb_backtrace() at kdb_backtrace+0x39/frame 0xfffffe048b9b1350
>> > > vpanic() at vpanic+0x126/frame 0xfffffe048b9b1390
>> > > panic() at panic+0x43/frame 0xfffffe048b9b13f0
>> > > trap_fatal() at trap_fatal+0x3a2/frame 0xfffffe048b9b1450
>> > > trap_pfault() at trap_pfault+0x22f/frame 0xfffffe048b9b14f0
>> > > trap() at trap+0x670/frame 0xfffffe048b9b1710
>> > > calltrap() at calltrap+0x8/frame 0xfffffe048b9b1710
>> > > --- trap 0xc, rip = 0xffffffff805e759b, rsp = 0xfffffe048b9b17d0, rbp =
> 0xfffffe048b9b17e0 ---
>> > > __mtx_assert() at __mtx_assert+0x3b/frame 0xfffffe048b9b17e0
>> > > knote() at knote+0x39/frame 0xfffffe048b9b1830
>> > > pipeclose() at pipeclose+0xbe/frame 0xfffffe048b9b1860
>> >
>> > Can you show which line this is via kgdb?  Can you also 'p *cpipe'
>> > and 'p *ppipe'?
>> >
>>
>>
>> Looks like its in here:
>> (kgdb) whe
>> #0  doadump (textdump=1) at pcpu.h:219
>> #1  0xffffffff805fb2a7 in kern_reboot (howto=260)
>> at ../../../kern/kern_shutdown.c:452
>> #2  0xffffffff805fb7b5 in vpanic (fmt=<value optimized out>, ap=<value
>> optimized out>) at ../../../kern/kern_shutdown.c:759
>> #3  0xffffffff805fb803 in panic (fmt=<value optimized out>)
>> at ../../../kern/kern_shutdown.c:688
>> #4  0xffffffff80977852 in trap_fatal (frame=<value optimized out>,
>> eva=<value optimized out>) at ../../../amd64/amd64/trap.c:882
>> #5  0xffffffff80977a8f in trap_pfault (frame=0x0, usermode=<value
>> optimized out>) at ../../../amd64/amd64/trap.c:699
>> #6  0xffffffff809772a0 in trap (frame=0xfffffe048c3df6e0)
>> at ../../../amd64/amd64/trap.c:463
>> #7  0xffffffff8095c7e2 in calltrap ()
>> at ../../../amd64/amd64/exception.S:232
>> #8  0xffffffff805e759b in __mtx_assert (c=0x18, what=4,
>> file=0xffffffff80ca0bcb "../../../kern/kern_event.c", line=1960)
>> at ../../../kern/kern_mutex.c:791
>> #9  0xffffffff805c2099 in knote (list=0xfffff8003498aae0, hint=0,
>> lockflags=1) at ../../../kern/kern_event.c:1822
>> #10 0xffffffff806510fe in pipeclose (cpipe=0xfffff8003498aa18)
>> at ../../../kern/sys_pipe.c:1655
>> #11 0xffffffff80651019 in pipe_dtor (dpipe=<value optimized out>)
>> at ../../../kern/sys_pipe.c:395
>> #12 0xffffffff80559924 in fifo_close (ap=<value optimized out>)
>> at ../../../fs/fifofs/fifo_vnops.c:115
>> #13 0xffffffff80a6ba6a in VOP_CLOSE_APV (vop=<value optimized out>,
>> a=<value optimized out>) at vnode_if.c:535
>> #14 0xffffffff806acc09 in vn_close (vp=0xfffff8032000cce8, flags=6,
>> file_cred=0xfffff8040400d200, td=0xfffff804044f9490) at vnode_if.h:225
>> #15 0xffffffff806abad8 in vn_closefile (fp=0xfffff803b2f3c410,
>> td=0xfffff804044f9490) at ../../../kern/vfs_vnops.c:1481
>> #16 0xffffffff805b8789 in _fdrop (fp=0xfffff803b2f3c410, td=0x4) at
>> file.h:342
>> #17 0xffffffff805bb0e1 in closef (fp=0xfffff803b2f3c410,
>> td=0xfffff804044f9490) at ../../../kern/kern_descrip.c:2415
>> #18 0xffffffff805b8bf0 in closefp (fdp=0xfffff800263f5000, fd=<value
>> optimized out>, fp=0xfffff803b2f3c410, td=0xfffff804044f9490,
>> holdleaders=<value optimized out>) at ../../../kern/kern_descrip.c:1257
>> #19 0xffffffff80a332b5 in ia32_syscall (frame=0xfffffe048c3dfbc0) at
>> subr_syscall.c:135
>> #20 0xffffffff8095cdc5 in Xint0x80_syscall () at ia32_exception.S:73
>> #21 0x00000000210f7804 in ?? ()
>> Previous frame inner to this frame (corrupt stack?)
>> Current language:  auto; currently minimal
>>
>>
>>
>> ----------------
>>
>> (kgdb) f 10
>> #10 0xffffffff806510fe in pipeclose (cpipe=0xfffff8003498aa18)
>> at ../../../kern/sys_pipe.c:1655
>> 1655    ../../../kern/sys_pipe.c: No such file or directory.
>>         in ../../../kern/sys_pipe.c
>> (kgdb) p *cpipe
>> $1 = {pipe_buffer = {cnt = 0, in = 0, out = 0, size = 0, buffer = 0x0},
>> pipe_map = {cnt = 0, pos = 0, npages = 0, ms = {0x0 <repeats 17
>> times>}}, pipe_sel = {si_tdlist = {tqh_first = 0x0, tqh_last = 0x0},
>> si_note = {kl_list = {
>>         slh_first = 0x0}, kl_lock = 0, kl_unlock = 0, kl_assert_locked =
>> 0xffffffff805c25c0 <knlist_mtx_assert_locked>, kl_assert_unlocked =
>> 0xffffffff805c25e0 <knlist_mtx_assert_unlocked>, kl_lockarg = 0x0},
>> si_mtx = 0x0},
>>   pipe_atime = {tv_sec = 1399120887, tv_nsec = 0}, pipe_mtime = {tv_sec
>> = 1399120887, tv_nsec = 0}, pipe_ctime = {tv_sec = 1399120887, tv_nsec =
>> 0}, pipe_sigio = 0x0, pipe_peer = 0xfffff8003498a8b8, pipe_pair =
>> 0xfffff8003498a8b8,
>>   pipe_state = 2432, pipe_busy = 0, pipe_present = 3, pipe_wgen = 0,
>> pipe_ino = 4294967295}
>>
>> (kgdb) p *ppipe
>> $2 = {pipe_buffer = {cnt = 0, in = 0, out = 0, size = 0, buffer = 0x0},
>> pipe_map = {cnt = 0, pos = 0, npages = 0, ms = {0x0 <repeats 17
>> times>}}, pipe_sel = {si_tdlist = {tqh_first = 0x0, tqh_last = 0x0},
>> si_note = {kl_list = {
>>         slh_first = 0x0}, kl_lock = 0, kl_unlock = 0, kl_assert_locked =
>> 0xffffffff805c25c0 <knlist_mtx_assert_locked>, kl_assert_unlocked =
>> 0xffffffff805c25e0 <knlist_mtx_assert_unlocked>, kl_lockarg = 0x0},
>> si_mtx = 0x0},
>>   pipe_atime = {tv_sec = 1399120887, tv_nsec = 0}, pipe_mtime = {tv_sec
>> = 1399120887, tv_nsec = 0}, pipe_ctime = {tv_sec = 1399120887, tv_nsec =
>> 0}, pipe_sigio = 0x0, pipe_peer = 0xfffff8003498a8b8, pipe_pair =
>> 0xfffff8003498a8b8,
>>   pipe_state = 2432, pipe_busy = 0, pipe_present = 3, pipe_wgen = 0,
>> pipe_ino = 4294967295}
>
> So the knlist for both of these has already been destroyed (knlist_destroy
> clears kl_lock, but not the assert function pointers).  Note that pipe_present
> is set to PIPE_FINALIZED for both pipes here.   Can you do an 'l' at frame
> 10 to see exactly which line is being called?

#10 0xffffffff806510fe in pipeclose (cpipe=0xfffff8028a6c6730) at
../../../kern/sys_pipe.c:1655

(kgdb) frame 10
#10 0xffffffff806510fe in pipeclose (cpipe=0xfffff8028a6c6730) at
../../../kern/sys_pipe.c:1655
1655    ../../../kern/sys_pipe.c: No such file or directory.
        in ../../../kern/sys_pipe.c
(kgdb) l
1650    in ../../../kern/sys_pipe.c
(kgdb)


 1639. /*
 1640. * shutdown the pipe
 1641. */
 1642. static void
 1643. pipeclose(cpipe)
 1644. struct pipe *cpipe;
 1645. {
 1646. struct pipepair *pp;
 1647. struct pipe *ppipe;
 1648.
 1649. KASSERT(cpipe != NULL, ("pipeclose: cpipe == NULL"));
 1650.
 1651. PIPE_LOCK(cpipe);
 1652. pipelock(cpipe, 0);
 1653. pp = cpipe->pipe_pair;
 1654.
 1655. pipeselwakeup(cpipe);

pipeclose() gets called from pipe_dtor()

  384. void
  385. pipe_dtor(struct pipe *dpipe)
  386. {
  387. ino_t ino;
  388.
  389. ino = dpipe->pipe_ino;
  390. funsetown(&dpipe->pipe_sigio);
  391. pipeclose(dpipe);                    <---------------
  392. if (dpipe->pipe_state & PIPE_NAMED) {
  393. dpipe = dpipe->pipe_peer;
  394. funsetown(&dpipe->pipe_sigio);
  395. pipeclose(dpipe);
  396. }
  397. if (ino != 0 && ino != (ino_t)-1)
  398. free_unr(pipeino_unr, ino);
  399. }

(kgdb) f 11
#11 0xffffffff80651019 in pipe_dtor (dpipe=<value optimized out>) at
../../../kern/sys_pipe.c:395
395     ../../../kern/sys_pipe.c: No such file or directory.
        in ../../../kern/sys_pipe.c
(kgdb) p *dpipe
$8 = {pipe_buffer = {cnt = 2160683902, in = 4294967295, out =
2165433456, size = 4294967295, buffer = 0xfffff803c220be70 ""},
pipe_map = {
    cnt = 18446735278181777408, pos = 18446735295352500696, npages =
-1841788584, ms = {0x0, 0x0, 0xfffff80125a6a798, 0x0,
0xfffff803c2b7b2a0,
      0xfffff803c2b7b2c0, 0x0, 0xffffffff80c96b7e, 0x6fb0008, 0x0,
0xfffff80060c08490, 0x1500000000, 0x60, 0xffffffff80cb7fa9, 0x1030000,
0x0, 0x4}},
  pipe_sel = {si_tdlist = {tqh_first = 0xfffff801cb464068, tqh_last =
0xfffff8020bfa9b10}, si_note = {kl_list = {slh_first =
0xfffff8022bb72648},
      kl_lock = 0xffffffff80cb7fb9 <global_opts+1769>, kl_unlock =
0x5230000, kl_assert_locked = 0, kl_assert_unlocked = 0x1,
      kl_lockarg = 0xffffffff81105f80}, si_mtx = 0x0}, pipe_atime =
{tv_sec = 0, tv_nsec = 0}, pipe_mtime = {tv_sec = -8788387676160,
    tv_nsec = -8788387676160}, pipe_ctime = {tv_sec = 0, tv_nsec =
-8788387675872}, pipe_sigio = 0x0, pipe_peer = 0x0, pipe_pair = 0x0,
  pipe_state = 3410379072, pipe_busy = -2047, pipe_present = 0,
pipe_wgen = 0, pipe_ino = 0}
(kgdb)

which gets called from fifo_cleanup()

  106. static void
  107. fifo_cleanup(struct vnode *vp)
  108. {
  109. struct fifoinfo *fip;
  110.
  111. ASSERT_VOP_ELOCKED(vp, "fifo_cleanup");
  112. fip = vp->v_fifoinfo;
  113. if (fip->fi_readers == 0 && fip->fi_writers == 0) {
  114. vp->v_fifoinfo = NULL;
  115. pipe_dtor(fip->fi_pipe);     <-----------------------------
  116. free(fip, M_VNODE);
  117. }
  118. }

(kgdb) p *fip->fi_pipe
$7 = {pipe_buffer = {cnt = 7562869, in = 1701147238, out = 761557858,
size = 1970170230,
    buffer = 0x736265657266006d <Address 0x736265657266006d out of
bounds>}, pipe_map = {cnt = 7596447167107706212, pos =
7022344801864938862,
    npages = 1852402688, ms = {0x78756e696c006d76, 0x696c00646961722d,
0x706177732d78756e, 0x697361622d736d00, 0x6d00617461642d63,
0x61642d6d646c2d73,
      0x646c2d736d006174, 0x61646174656d2d6d, 0x65722d736d006174,
0x6e00646576726573, 0x63632d6473627465, 0x64736274656e0064,
0x74656e006467632d,
      0x7366662d647362, 0x6c2d64736274656e, 0x736274656e007366,
0x6e00646961722d64}}, pipe_sel = {si_tdlist = {tqh_first =
0x77732d6473627465,
      tqh_last = 0x7261776d76007061}, si_note = {kl_list = {slh_first
= 0x760073666d762d65}, kl_lock = 0x6d762d657261776d, kl_unlock =
0x6d7600676169646b,
      kl_assert_locked = 0x7365722d65726177, kl_assert_unlocked =
0x6d76006465767265, kl_lockarg = 0x6173762d65726177}, si_mtx =
0x4f4547007264686e},
  pipe_atime = {tv_sec = 2322261270122749773, tv_nsec =
2675249699185255283}, pipe_mtime = {tv_sec = 8245071809811652723,
tv_nsec = 7450486642355495269},
  pipe_ctime = {tv_sec = 2406159642925495145, tv_nsec =
3399705548884410378}, pipe_sigio = 0x2f6d6f65672f2e2e, pipe_peer =
0x705f672f74726170,
  pipe_pair = 0x5f6700632e747261, pipe_state = 1953653104, pipe_busy =
1886547807, pipe_present = 7233896, pipe_wgen = 623407909, pipe_ino =
620767603}
(kgdb)


> Also, it seems like 'cpipe'
> and 'pipe' might be the same.

Let me know if you want to any more info.

thanks for looking at this,
Hiren


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