svn commit: r360233 - in head: contrib/jemalloc . . . : This partially breaks a 2-socket 32-bit powerpc (old PowerMac G4) based on head -r360311
Mark Millard
marklmi at yahoo.com
Sun May 3 18:08:36 UTC 2020
[At around 4AM local time dhcient got a signal 11,
despite the jemalloc revert. The other exmaples
have not happened.]
On 2020-May-2, at 18:46, Mark Millard <marklmi at yahoo.com> wrote:
> [I'm only claiming the new jemalloc is involved and that
> reverting avoids the problem.]
>
> I've been reporting to some lists problems with:
>
> dhclient
> sendmail
> rpcbind
> mountd
> nfsd
>
> getting SIGSEGV (signal 11) crashes and some core
> dumps on the old 2-socket (1 core per socket) 32-bit
> PowerMac G4 running head -r360311.
>
> Mikaël Urankar sent a note suggesting that I try
> testing reverting head -r360233 for my head -r360311
> context. He got it right . . .
>
>
> Context:
>
> The problem was noticed by an inability to have
> other machines do a:
>
> mount -onoatime,soft OLDPOWERMAC-LOCAL-IP:/... /mnt
>
> sort of operation and to have succeed. By contrast, on
> the old PowerMac G4 I could initiate mounts against
> other machines just fine.
>
> I do not see any such problems on any of (all based
> on head -r360311):
>
> powerpc64 (old PowerMac G5 2-sockets with 2 cores each)
> armv7 (OrangePi+ 2ed)
> aarch64 (Rock64, RPi4, RPi3,
> OverDrive 1000,
> Macchiatobin Double Shot)
> amd64 (ThreadRipper 1950X)
>
> So I expect something 32-bit powerpc specific
> is somehow involved, even if jemalloc is only
> using whatever it is.
>
> (A kyua run with a debug kernel did not find other
> unexpected signal 11 sources on the 32-bit PowerMac
> compared to past kyua runs, at least that I noticed.
> There were a few lock order reversals that I do not
> know if they are expected or known-safe or not.
> I've reported those reversals to the lists as well.)
>
>
> Recent experiments based on the suggestion:
>
> Doing the buildworld, buildkernel and installing just
> the new kernel and rebooting made no difference.
>
> But then installing the new world and rebooting did
> make things work again: I no longer get core files
> for the likes of (old cores from before the update):
>
> # find / -name "*.core" -print
> /var/spool/clientmqueue/sendmail.core
> /rpcbind.core
> /mountd.core
> /nfsd.core
>
> Nor do I see the various notices for sendmail
> signal 11's that did not leave behind a core file
> --or for dhclient (no core file left behind).
> And I can mount the old PowerMac's drive from
> other machines just fine.
>
>
> Other notes:
>
> I do not actively use sendmail but it was left
> to do its default things, partially to test if
> such default things are working. Unfortunately,
> PowerMacs have a problematical status under
> FreeBSD and my context has my historical
> experiments with avoiding various problems.
Looking, I see that I got a:
pid 572 (dhclient), jid 0, uid 0: exited on signal 11 (core dumped)
notice under the reverted build. No instances
of the other examples. This is the first that a
dhclient example has produced a .core file.
gdb indicates 0x5180936c for r7 in:
lwz r8,36(r7)
as leading to the failure. This was in
arena_dalloc_bin_locked_impl (where
arena_slab_reg_dalloc and bitmap_unset
were apparently inlined).
The chain for the example seems to be:
fork_privchld -> dispatch_imsg -> jemalloc
For reference . . .
# gdb dhclient /dhclient.core
GNU gdb (GDB) 9.1 [GDB v9.1 for FreeBSD]
Copyright (C) 2020 Free Software Foundation, Inc.
License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
. . .
Reading symbols from dhclient...
Reading symbols from /usr/lib/debug//sbin/dhclient.debug...
[New LWP 100089]
Core was generated by `dhclient: gem0 [priv]'.
Program terminated with signal SIGSEGV, Segmentation fault.
#0 bitmap_unset (bitmap=0x50407164, binfo=<optimized out>, bit=167842154) at /usr/powerpc32_src/contrib/jemalloc/include/jemalloc/internal/bitmap.h:341
341 /usr/powerpc32_src/contrib/jemalloc/include/jemalloc/internal/bitmap.h: No such file or directory.
(gdb) bt -full
#0 bitmap_unset (bitmap=0x50407164, binfo=<optimized out>, bit=167842154) at /usr/powerpc32_src/contrib/jemalloc/include/jemalloc/internal/bitmap.h:341
goff = <optimized out>
gp = 0x51809390
propagate = <optimized out>
g = <optimized out>
i = <optimized out>
#1 arena_slab_reg_dalloc (slab=0x50407140, slab_data=0x50407164, ptr=0x50088b50) at jemalloc_arena.c:273
bin_info = <optimized out>
binind = 0
regind = 167842154
#2 arena_dalloc_bin_locked_impl (tsdn=0x5009f018, arena=<optimized out>, slab=<optimized out>, ptr=<optimized out>, junked=<optimized out>) at jemalloc_arena.c:1540
slab_data = <optimized out>
binind = <optimized out>
bin_info = <optimized out>
bin = <optimized out>
nfree = <optimized out>
#3 0x502916a8 in __je_arena_dalloc_bin_junked_locked (tsdn=<optimized out>, arena=<optimized out>, extent=<optimized out>, ptr=<optimized out>) at jemalloc_arena.c:1559
No locals.
#4 0x50250d2c in __je_tcache_bin_flush_small (tsd=0x5009f018, tcache=<optimized out>, tbin=0x5009f1c0, binind=<optimized out>, rem=24) at jemalloc_tcache.c:149
ptr = <optimized out>
i = 0
extent = 0x50407140
bin_arena = 0x50400380
bin = <optimized out>
ndeferred = 0
merged_stats = <optimized out>
arena = 0x50400380
nflush = 75
__vla_expr0 = <optimized out>
item_extent = 0xffffd1f0
#5 0x502508a0 in __je_tcache_event_hard (tsd=<optimized out>, tcache=0x5009f108) at jemalloc_tcache.c:54
tbin_info = <optimized out>
binind = 7
tbin = 0x5009f1c0
#6 0x5029a684 in __free (ptr=0x500530c0) at /usr/powerpc32_src/contrib/jemalloc/include/jemalloc/internal/rtree.h:374
tcache = 0x5009f108
tsd = <optimized out>
log_var = <optimized out>
log_var = <optimized out>
#7 0x10025994 in dispatch_imsg (ifix=<optimized out>, fd=10) at /usr/powerpc32_src/sbin/dhclient/privsep.c:215
hdr = {code = IMSG_SCRIPT_WRITE_PARAMS, len = 3225}
lease = {next = 0x0, expiry = 1588504529, renewal = 1588504229, rebind = 1588504454, address = {len = 4, iabuf = "\300\250\001i", '\000' <repeats 11 times>}, nextserver = {len = 4,
iabuf = '\000' <repeats 15 times>}, server_name = 0x0, filename = 0x0, medium = 0x0, is_static = 0, is_bootp = 0, options = {{len = 0, data = 0x0}, {len = 4,
data = 0x500530c8 "\377\377\377"}, {len = 0, data = 0x0}, {len = 4, data = 0x500530d0 "\300\250\001\001"}, {len = 0, data = 0x0}, {len = 0, data = 0x0}, {len = 4,
data = 0x500530d8 "\300\250\001\001"}, {len = 0, data = 0x0}, {len = 0, data = 0x0}, {len = 0, data = 0x0}, {len = 0, data = 0x0}, {len = 0, data = 0x0}, {len = 0, data = 0x0}, {
len = 0, data = 0x0}, {len = 0, data = 0x0}, {len = 20, data = 0x50055200 "hsd1.or.comcast.net."}, {len = 0, data = 0x0} <repeats 35 times>, {len = 4, data = 0x500530e0 ""}, {len = 0,
data = 0x0}, {len = 1, data = 0x500530e8 "\005"}, {len = 4, data = 0x500530f0 "\300\250\001\001"}, {len = 0, data = 0x0} <repeats 201 times>}}
medium_len = <optimized out>
medium = <optimized out>
totlen = 3225
filename_len = <optimized out>
filename = 0x0
ret = <optimized out>
buf = <optimized out>
mtu = <optimized out>
servername_len = <optimized out>
servername = 0x0
reason_len = <optimized out>
reason = <optimized out>
--Type <RET> for more, q to quit, c to continue without paging--
prefix_len = <optimized out>
prefix = 0x500530c0 "new_"
i = 0
optlen = 0
#8 0x100189f4 in fork_privchld (fd=10, fd2=<optimized out>) at /usr/powerpc32_src/sbin/dhclient/dhclient.c:2847
pfd = {{fd = 10, events = 1, revents = 1}}
nfds = <optimized out>
#9 0x10017a80 in main (argc=<optimized out>, argv=<optimized out>) at /usr/powerpc32_src/sbin/dhclient/dhclient.c:505
pipe_fd = {10, 11}
rights = {cr_rights = {1342801412, 18446706484155777024}}
immediate_daemon = 0
i = 0
ch = <optimized out>
otherpid = 8
pw = 0x5039b9d8
fd = <optimized out>
capmode = <optimized out>
(gdb) disass
Dump of assembler code for function arena_dalloc_bin_locked_impl:
0x502916b8 <+0>: mflr r0
0x502916bc <+4>: stw r0,4(r1)
0x502916c0 <+8>: stwu r1,-48(r1)
0x502916c4 <+12>: stw r30,40(r1)
0x502916c8 <+16>: stw r24,16(r1)
0x502916cc <+20>: stw r25,20(r1)
0x502916d0 <+24>: stw r26,24(r1)
0x502916d4 <+28>: stw r27,28(r1)
0x502916d8 <+32>: stw r28,32(r1)
0x502916dc <+36>: stw r29,36(r1)
0x502916e0 <+40>: bl 0x502916e4 <arena_dalloc_bin_locked_impl+44>
0x502916e4 <+44>: mr r27,r3
0x502916e8 <+48>: mflr r30
0x502916ec <+52>: addis r30,r30,14
0x502916f0 <+56>: addi r30,r30,7788
0x502916f4 <+60>: mr r28,r4
0x502916f8 <+64>: lwz r4,5856(r30)
0x502916fc <+68>: lwz r3,4(r5)
0x50291700 <+72>: mr r29,r5
0x50291704 <+76>: andi. r5,r7,1
0x50291708 <+80>: mr r26,r6
0x5029170c <+84>: lbz r4,0(r4)
0x50291710 <+88>: rlwinm r5,r3,14,25,31
0x50291714 <+92>: mulli r24,r5,224
0x50291718 <+96>: mulli r25,r5,44
0x5029171c <+100>: cmpwi cr1,r4,0
0x50291720 <+104>: cror 4*cr5+lt,4*cr1+eq,gt
0x50291724 <+108>: bge cr5,0x50291a2c <arena_dalloc_bin_locked_impl+884>
0x50291728 <+112>: lwz r4,0(r29)
0x5029172c <+116>: lwz r6,6036(r30)
0x50291730 <+120>: lwz r7,8(r29)
0x50291734 <+124>: rlwinm r8,r5,2,0,29
0x50291738 <+128>: li r9,1
0x5029173c <+132>: add r24,r28,r24
0x50291740 <+136>: lwzx r6,r6,r8
0x50291744 <+140>: subf r7,r7,r26
0x50291748 <+144>: mulhwu r6,r6,r7
0x5029174c <+148>: rlwinm r7,r6,29,3,29
0x50291750 <+152>: add r7,r29,r7
=> 0x50291754 <+156>: lwz r8,36(r7)
0x50291758 <+160>: clrlwi r10,r6,27
0x5029175c <+164>: slw r9,r9,r10
0x50291760 <+168>: xor r9,r9,r8
0x50291764 <+172>: cmplwi r8,0
0x50291768 <+176>: stw r9,36(r7)
0x5029176c <+180>: bne 0x502917e4 <arena_dalloc_bin_locked_impl+300>
0x50291770 <+184>: lwz r7,4408(r30)
0x50291774 <+188>: mulli r8,r5,44
0x50291778 <+192>: add r5,r7,r8
0x5029177c <+196>: lwz r5,16(r5)
0x50291780 <+200>: cmplwi r5,2
0x50291784 <+204>: blt 0x502917e4 <arena_dalloc_bin_locked_impl+300
. . .
(gdb) info reg
r0 0x502916a8 1344870056
r1 0xffffd1a0 4294955424
r2 0x500a6018 1342857240
r3 0x0 0
r4 0x0 0
r5 0x0 0
r6 0xa01116a 167842154
r7 0x5180936c 1367380844
r8 0x0 0
r9 0x1 1
r10 0x1e 30
r11 0x5005d114 1342558484
r12 0x84000c00 2214595584
r13 0x0 0
r14 0xffffd1f0 4294955504
r15 0xfffffffc 4294967292
r16 0x4a 74
r17 0x4b 75
r18 0x0 0
r19 0x504009a0 1346374048
r20 0x0 0
r21 0xffffd1f0 4294955504
r22 0x620 1568
r23 0x50400380 1346372480
r24 0x50400380 1346372480
r25 0x0 0
r26 0x50088b50 1342737232
r27 0x5009f018 1342828568
r28 0x50400380 1346372480
r29 0x50407140 1346400576
r30 0x50373550 1345795408
r31 0xffffd310 4294955792
pc 0x50291754 0x50291754 <arena_dalloc_bin_locked_impl+156>
msr <unavailable>
cr 0x42480c00 1112017920
lr 0x502916e4 0x502916e4 <arena_dalloc_bin_locked_impl+44>
ctr 0x5005d114 1342558484
xer 0x0 0
fpscr 0x0 0
vscr <unavailable>
vrsave <unavailable>
===
Mark Millard
marklmi at yahoo.com
( dsl-only.net went
away in early 2018-Mar)
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