https://gcc.gnu.org/bugzilla/show_bug.cgi?id=92564
Bug ID: 92564
Summary: libgo regression in runtime test resulting in SIGSEGV
on ppc64le
Product: gcc
Version: 10.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: go
Assignee: ian at airs dot com
Reporter: boger at gcc dot gnu.org
CC: cmang at google dot com, seurer at us dot ibm.com
Target Milestone: ---
When running the runtime test on ppc64le from trunk, a SIGSEV results. This
happens consistently now, but we have been unable to identify the commit where
this was introduced because it was intermittent when it started. On one machine
it fails on r276474.
The failing output:
[signal SIGSEGV: segmentation violation code=0x2 addr=0x7c2d2cb30000
pc=0x100af074]
runtime stack:
runtime.dopanic_m
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/panic.go:1181
runtime.fatalthrow
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/panic.go:1047
runtime.throw
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/panic.go:1018
runtime.sigpanic
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/signal_unix.go:337
runtime.sighandler
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/signal_sighandler.go:100
runtime.sigtrampgo
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/signal_unix.go:314
runtime.sigtramp
../../../src/libgo/runtime/go-signal.c:86
:0
runtime.scanstackblock
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/mgcmark.go:1059
doscanstack1
../../../src/libgo/runtime/stack.c:91
runtime.doscanstack
../../../src/libgo/runtime/stack.c:38
runtime.scanstack
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/mgcmark.go:653
runtime.scang
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/proc.go:914
runtime.markroot..func1
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/mgcmark.go:206
runtime.systemstack
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/stubs.go:60
runtime.markroot
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/mgcmark.go:187
runtime.gcDrain
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/mgcmark.go:764
runtime.gcBgMarkWorker..func2
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/mgc.go:1906
runtime.systemstack..func1
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/stubs.go:63
runtime_mstart
../../../src/libgo/runtime/proc.c:593
goroutine 102 [GC worker (idle)]:
runtime.mcall
../../../src/libgo/runtime/proc.c:343
runtime.systemstack
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/stubs.go:66
runtime.gcBgMarkWorker
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/mgc.go:1893
runtime.kickoff
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/proc.go:1213
created by runtime.gcBgMarkStartWorkers
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/mgc.go:1785
+0xc8
goroutine 1 [chan receive (scan)]:
runtime.mcall
../../../src/libgo/runtime/proc.c:343
runtime.gopark
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/proc.go:339
runtime.goparkunlock
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/proc.go:345
runtime.chanrecv
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/chan.go:546
runtime.chanrecv1
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/chan.go:423
testing.T.Run
../../../src/libgo/go/testing/testing.go:961
testing.runTests..func1
../../../src/libgo/go/testing/testing.go:1202
testing.tRunner
../../../src/libgo/go/testing/testing.go:909
testing.runTests
../../../src/libgo/go/testing/testing.go:1200
testing.M.Run
../../../src/libgo/go/testing/testing.go:1117
runtime_test.TestMain
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/crash_test.go:28
main.main
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/_testmain.go:515
runtime.main
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/proc.go:235
goroutine 2 [force gc (idle)]:
runtime.mcall
../../../src/libgo/runtime/proc.c:343
runtime.gopark
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/proc.go:339
runtime.goparkunlock
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/proc.go:345
runtime.forcegchelper
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/proc.go:288
runtime.kickoff
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/proc.go:1213
created by runtime..import
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/proc.go:273
+0x504
goroutine 3 [finalizer wait]:
runtime.mcall
../../../src/libgo/runtime/proc.c:343
runtime.gopark
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/proc.go:339
runtime.goparkunlock
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/proc.go:345
runtime.runfinq
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/mfinal.go:146
runtime.kickoff
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/proc.go:1213
created by runtime.SetFinalizer
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/mfinal.go:370
+0x340
goroutine 4 [GC sweep wait]:
runtime.mcall
../../../src/libgo/runtime/proc.c:343
runtime.gopark
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/proc.go:339
runtime.goparkunlock
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/proc.go:345
runtime.bgsweep
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/mgcsweep.go:72
runtime.kickoff
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/proc.go:1213
created by runtime.gcenable
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/mgc.go:211
+0xbc
goroutine 5 [GC scavenge wait]:
runtime.mcall
../../../src/libgo/runtime/proc.c:343
runtime.gopark
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/proc.go:339
runtime.goparkunlock
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/proc.go:345
runtime.bgscavenge
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/mgcscavenge.go:259
runtime.kickoff
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/proc.go:1213
created by runtime.gcenable
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/mgc.go:213
+0x10c
goroutine 6 [syscall]:
goroutine in C code; stack unavailable
created by time.startTimer
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/time.go:114
+0x1e8
goroutine 9 [chan receive]:
runtime.mcall
../../../src/libgo/runtime/proc.c:343
runtime.gopark
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/proc.go:339
runtime.goparkunlock
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/proc.go:345
runtime.chanrecv
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/chan.go:546
runtime.chanrecv1
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/chan.go:423
runtime_test.TestChan
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/chan_test.go:172
testing.tRunner
../../../src/libgo/go/testing/testing.go:909
runtime.kickoff
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/proc.go:1213
created by testing.T.Run
../../../src/libgo/go/testing/testing.go:960 +0x39c
goroutine 18 [timer goroutine (idle)]:
runtime.mcall
../../../src/libgo/runtime/proc.c:343
runtime.gopark
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/proc.go:339
runtime.goparkunlock
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/proc.go:345
runtime.timerproc
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/time.go:306
runtime.kickoff
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/proc.go:1213
created by runtime.timersBucket.addtimerLocked
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/time.go:170
+0x1b8
goroutine 34 [timer goroutine (idle)]:
runtime.mcall
../../../src/libgo/runtime/proc.c:343
runtime.gopark
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/proc.go:339
runtime.goparkunlock
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/proc.go:345
runtime.timerproc
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/time.go:306
runtime.kickoff
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/proc.go:1213
created by runtime.timersBucket.addtimerLocked
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/time.go:170
+0x1b8
goroutine 31 [GC assist wait]:
runtime.mcall
../../../src/libgo/runtime/proc.c:343
runtime.gopark
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/proc.go:339
runtime.goparkunlock
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/proc.go:345
runtime.gcParkAssist
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/mgcmark.go:532
runtime.gcAssistAlloc
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/mgcmark.go:396
runtime.mallocgc
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/malloc.go:948
runtime.newarray
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/malloc.go:1198
runtime.makeBucketArray
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/map.go:377
runtime.hashGrow
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/map.go:1097
runtime.mapassign_fast64
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/map_fast64.go:164
runtime_test.TestChan..func8
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/chan_test.go:165
runtime.kickoff
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/proc.go:1213
created by runtime_test.TestChan
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/chan_test.go:161
+0x10c4
goroutine 29 [GC assist wait]:
runtime.mcall
../../../src/libgo/runtime/proc.c:343
runtime.gopark
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/proc.go:339
runtime.goparkunlock
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/proc.go:345
runtime.gcParkAssist
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/mgcmark.go:532
runtime.gcAssistAlloc
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/mgcmark.go:396
runtime.mallocgc
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/malloc.go:948
runtime.growslice
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/slice.go:184
runtime.hmap.newoverflow
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/map.go:282
runtime.mapassign_fast64
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/map_fast64.go:170
runtime_test.TestChan..func8
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/chan_test.go:165
runtime.kickoff
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/proc.go:1213
created by runtime_test.TestChan
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/chan_test.go:161
+0x10c4
goroutine 113 [GC worker (idle)]:
runtime.mcall
../../../src/libgo/runtime/proc.c:343
runtime.gopark
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/proc.go:339
runtime.gcBgMarkWorker
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/mgc.go:1839
runtime.kickoff
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/proc.go:1213
created by runtime.gcBgMarkStartWorkers
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/mgc.go:1785
+0xc8
goroutine 60 [timer goroutine (idle)]:
runtime.mcall
../../../src/libgo/runtime/proc.c:343
runtime.gopark
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/proc.go:339
runtime.goparkunlock
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/proc.go:345
runtime.timerproc
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/time.go:306
runtime.kickoff
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/proc.go:1213
created by runtime.timersBucket.addtimerLocked
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/time.go:170
+0x1b8
goroutine 28 [chan send]:
runtime.mcall
../../../src/libgo/runtime/proc.c:343
runtime.gopark
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/proc.go:339
runtime.goparkunlock
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/proc.go:345
runtime.chansend
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/chan.go:253
runtime.chansend1
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/chan.go:139
runtime_test.TestChan..func7
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/chan_test.go:155
runtime.kickoff
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/proc.go:1213
created by runtime_test.TestChan
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/chan_test.go:153
+0xffc
goroutine 61 [GC worker (idle)]:
runtime.mcall
../../../src/libgo/runtime/proc.c:343
runtime.gopark
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/proc.go:339
runtime.gcBgMarkWorker
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/mgc.go:1839
runtime.kickoff
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/proc.go:1213
created by runtime.gcBgMarkStartWorkers
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/mgc.go:1785
+0xc8
goroutine 27 [chan send]:
runtime.mcall
../../../src/libgo/runtime/proc.c:343
runtime.gopark
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/proc.go:339
runtime.goparkunlock
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/proc.go:345
runtime.chansend
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/chan.go:253
runtime.chansend1
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/chan.go:139
runtime_test.TestChan..func7
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/chan_test.go:155
runtime.kickoff
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/proc.go:1213
created by runtime_test.TestChan
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/chan_test.go:153
+0xffc
goroutine 26 [chan send]:
runtime.mcall
../../../src/libgo/runtime/proc.c:343
runtime.gopark
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/proc.go:339
runtime.goparkunlock
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/proc.go:345
runtime.chansend
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/chan.go:253
runtime.chansend1
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/chan.go:139
runtime_test.TestChan..func7
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/chan_test.go:155
runtime.kickoff
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/proc.go:1213
created by runtime_test.TestChan
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/chan_test.go:153
+0xffc
goroutine 25 [chan send]:
runtime.mcall
../../../src/libgo/runtime/proc.c:343
runtime.gopark
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/proc.go:339
runtime.goparkunlock
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/proc.go:345
runtime.chansend
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/chan.go:253
runtime.chansend1
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/chan.go:139
runtime_test.TestChan..func7
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/chan_test.go:155
runtime.kickoff
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/proc.go:1213
created by runtime_test.TestChan
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/chan_test.go:153
+0xffc
goroutine 103 [GC worker (idle)]:
runtime.mcall
../../../src/libgo/runtime/proc.c:343
runtime.gopark
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/proc.go:339
runtime.gcBgMarkWorker
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/mgc.go:1839
runtime.kickoff
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/proc.go:1213
created by runtime.gcBgMarkStartWorkers
/home/boger/gccgo.work/trunk/bld/powerpc64le-linux/libgo/gotest48232/test/mgc.go:1785
+0xc8
Keeping gotest48232
FAIL: runtime
gdb shows this stack trace at the point of the SEGSEV:
Thread 5 "a.out" received signal SIGSEGV, Segmentation fault.
[Switching to Thread 0x7ffff0fceff0 (LWP 45320)]
runtime.scanstackblock (b=<optimized out>, n=<optimized out>, gcw=<optimized
out>) at mgcmark.go:1059
1059 if obj, span, objIndex := findObject(obj, b, i, true);
obj != 0 {
(gdb) bt
#0 runtime.scanstackblock (b=<optimized out>, n=<optimized out>,
gcw=<optimized out>) at mgcmark.go:1059
#1 0x00007ffff700578c in doscanstack1 (gp=<optimized out>, gcw=<optimized
out>) at ../../../src/libgo/runtime/stack.c:91
#2 0x00007ffff70059c4 in runtime.doscanstack (gp=<optimized out>,
gcw=<optimized out>) at ../../../src/libgo/runtime/stack.c:38
#3 0x00000000100ad91c in runtime.scanstack (gp=gp@entry=0xc000000d80,
gcw=gcw@entry=0xc000023310) at mgcmark.go:653
#4 0x00000000100d1f68 in runtime.scang (gp=<optimized out>, gcw=<optimized
out>) at proc.go:914
#5 0x00000000100ac584 in runtime.markroot..func1 () at mgcmark.go:206
#6 0x00000000100f3780 in runtime.systemstack (fn=<optimized out>) at
stubs.go:60
#7 0x00000000100ac4cc in runtime.markroot (gcw=gcw@entry=0xc000023310,
i=<optimized out>) at mgcmark.go:187
#8 0x00000000100adf28 in runtime.gcDrain (gcw=<optimized out>,
flags=flags@entry=3) at mgcmark.go:764
#9 0x00000000100a6e5c in runtime.gcBgMarkWorker..func2 () at mgc.go:1906
#10 0x00000000100f3858 in runtime.systemstack..func1 (origg=<optimized out>) at
stubs.go:63
#11 0x00007ffff7004990 in runtime_mstart (arg=<optimized out>) at
../../../src/libgo/runtime/proc.c:593
#12 0x00007ffff770c3dc in __morestack () at
../../../src/libgcc/config/rs6000/morestack.S:204
#13 0x00007ffff770c17c in stack_split_initialize_thread (varg=0x7fffe4000c60)
at ../../../src/libgcc/generic-morestack-thread.c:127
#14 0x00007ffff60a885c in start_thread (arg=0x0) at pthread_create.c:463
#15 0x00007ffff6249028 in clone () at
../sysdeps/unix/sysv/linux/powerpc/powerpc64/clone.S:82
