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| author | Dmitriy Vyukov <dvyukov@google.com> | 2014-07-23 18:51:34 +0400 |
|---|---|---|
| committer | Dmitriy Vyukov <dvyukov@google.com> | 2014-07-23 18:51:34 +0400 |
| commit | 0603fbb01ca3778c08c0a445cd84195dbdc8fb3b (patch) | |
| tree | 8614c6f9a5d4696133809ea0fcb2b58e4e94f234 /src | |
| parent | b916dc19921a799c3fc9d1bcc704cfd0b0bf08d0 (diff) | |
| download | go-0603fbb01ca3778c08c0a445cd84195dbdc8fb3b.tar.xz | |
runtime: fix unexpected return pc for runtime.newstackcall
With cl/112640043 TestCgoDeadlockCrash episodically print:
unexpected return pc for runtime.newstackcall
After adding debug output I see the following trace:
runtime: unexpected return pc for runtime.newstackcall called from 0xc208011b00
runtime.throw(0x414da86)
src/pkg/runtime/panic.c:523 +0x77
runtime.gentraceback(0x40165fc, 0xba440c28, 0x0, 0xc208d15200, 0xc200000000, 0xc208ddfd20, 0x20, 0x0, 0x0, 0x300)
src/pkg/runtime/traceback_x86.c:185 +0xca4
runtime.callers(0x1, 0xc208ddfd20, 0x20)
src/pkg/runtime/traceback_x86.c:438 +0x98
mcommoninit(0xc208ddfc00)
src/pkg/runtime/proc.c:369 +0x5c
runtime.allocm(0xc208052000)
src/pkg/runtime/proc.c:686 +0xa6
newm(0x4017850, 0xc208052000)
src/pkg/runtime/proc.c:933 +0x27
startm(0xc208052000, 0x100000001)
src/pkg/runtime/proc.c:1011 +0xba
wakep()
src/pkg/runtime/proc.c:1071 +0x57
resetspinning()
src/pkg/runtime/proc.c:1297 +0xa1
schedule()
src/pkg/runtime/proc.c:1366 +0x14b
runtime.gosched0(0xc20808e240)
src/pkg/runtime/proc.c:1465 +0x5b
runtime.newstack()
src/pkg/runtime/stack.c:891 +0x44d
runtime: unexpected return pc for runtime.newstackcall called from 0xc208011b00
runtime.newstackcall(0x4000cbd, 0x4000b80)
src/pkg/runtime/asm_amd64.s:278 +0x6f
I suspect that it can happen on any stack split.
So don't unwind g0 stack.
Also, that comment is lying -- we can traceback w/o mcache,
CPU profiler does that.
LGTM=rsc
R=golang-codereviews
CC=golang-codereviews, khr, rsc
https://golang.org/cl/120040043
Diffstat (limited to 'src')
| -rw-r--r-- | src/pkg/runtime/proc.c | 5 |
1 files changed, 2 insertions, 3 deletions
diff --git a/src/pkg/runtime/proc.c b/src/pkg/runtime/proc.c index 55c58442ba..d65f605bd6 100644 --- a/src/pkg/runtime/proc.c +++ b/src/pkg/runtime/proc.c @@ -363,9 +363,8 @@ checkmcount(void) static void mcommoninit(M *mp) { - // If there is no mcache runtime·callers() will crash, - // and we are most likely in sysmon thread so the stack is senseless anyway. - if(g->m->mcache) + // g0 stack won't make sense for user (and is not necessary unwindable). + if(g != g->m->g0) runtime·callers(1, mp->createstack, nelem(mp->createstack)); mp->fastrand = 0x49f6428aUL + mp->id + runtime·cputicks(); |