runtime: Panic if newstack at runtime.acquireLockRank

[chainhelen]

What version of Go are you using (go version)?

$ go version
go version go1.15 linux/386

Does this issue reproduce with the latest release?

Yes

What operating system and processor architecture are you using (go env)?

go env Output

$ go env
GO111MODULE=""

GOARCH="386"

GOBIN=""

GOCACHE="/root/.cache/go-build"

GOENV="/root/.config/go/env"

GOEXE=""

GOFLAGS=""

GOHOSTARCH="386"

GOHOSTOS="linux"

GOINSECURE=""

GOMODCACHE="/root/go/pkg/mod"

GONOPROXY=""

GONOSUMDB=""

GOOS="linux"

GOPATH="/root/go"

GOPRIVATE=""

GOPROXY="https://proxy.golang.org,direct"

GOROOT="/root/go.master_v2"

GOSUMDB="sum.golang.org"

GOTMPDIR=""

GOTOOLDIR="/root/go.master_v2/pkg/tool/linux_386"

GCCGO="gccgo"

GO386="sse2"

AR="ar"

CC="gcc"

CXX="g++"

CGO_ENABLED="1"

GOMOD="/root/go.master_v2/src/go.mod"

CGO_CFLAGS="-g -O2"

CGO_CPPFLAGS=""

CGO_CXXFLAGS="-g -O2"

CGO_FFLAGS="-g -O2"

CGO_LDFLAGS="-g -O2"

PKG_CONFIG="pkg-config"

GOGCCFLAGS="-fPIC -m32 -pthread -fmessage-length=0 -fdebug-prefix-map=/tmp/go-build983115557=/tmp/go-build -gno-record-gcc-switches"

What did you do?

// cat main.go
package main

import "fmt"

func main() {
        fmt.Println("hello world!")
}

// Please notice it can't be reproducted if without -gcflags="all=-N -l".

go build -gcflags="all=-N -l" -o main main.go
./main

What did you expect to see?

No painc.

What did you see instead?

runtime: newstack at runtime.acquireLockRank+0x18 sp=0x888adac stack=[0x888a000, 0x888b000]
	morebuf={pc:0x807b8d8 sp:0x888adb0 lr:0x0}
	sched={pc:0x8052258 sp:0x888adac lr:0x0 ctxt:0x0}
runtime.casgstatus(0x88000e0, 0x2, 0x3)
	/root/go.master/src/runtime/proc.go:801 +0x58 fp=0x888ade0 sp=0x888adb0 pc=0x807b8d8
runtime.reentersyscall(0x80d68e5, 0x888ae0c)
	/root/go.master/src/runtime/proc.go:3027 +0x66 fp=0x888ae00 sp=0x888ade0 pc=0x80805a6
runtime.entersyscall()
	/root/go.master/src/runtime/proc.go:3076 +0x17 fp=0x888ae0c sp=0x888ae00 pc=0x80a1217
syscall.Syscall6(0x131, 0xffffff9c, 0x88a6000, 0x88a4000, 0x80, 0x0, 0x0, 0xa758010c, 0x0, 0x8069e02)
	/root/go.master/src/syscall/asm_linux_386.s:44 +0x5 fp=0x888ae10 sp=0x888ae0c pc=0x80d68e5
syscall.readlinkat(0xffffff9c, 0x80ff7ee, 0xe, 0x88a4000, 0x80, 0x80, 0x0, 0x0, 0x0)
	/root/go.master/src/syscall/zsyscall_linux_386.go:90 +0x123 fp=0x888ae6c sp=0x888ae10 pc=0x80d63b3
syscall.Readlink(0x80ff7ee, 0xe, 0x88a4000, 0x80, 0x80, 0x0, 0x0, 0x0)
	/root/go.master/src/syscall/syscall_linux.go:150 +0x75 fp=0x888aeac sp=0x888ae6c pc=0x80d5e35
os.Readlink(0x80ff7ee, 0xe, 0x0, 0x0, 0x0, 0x0)
	/root/go.master/src/os/file_unix.go:370 +0xba fp=0x888af18 sp=0x888aeac pc=0x80d990a
os.glob..func1(0x0, 0x0, 0x0, 0x0)
	/root/go.master/src/os/executable_procfs.go:29 +0x93 fp=0x888af5c sp=0x888af18 pc=0x80d9bf3
os.init()
	/root/go.master/src/os/executable_procfs.go:30 +0x198 fp=0x888af80 sp=0x888af5c pc=0x80d9e08
runtime.doInit(0x8160ae0)
	/root/go.master/src/runtime/proc.go:5559 +0x91 fp=0x888af98 sp=0x888af80 pc=0x8085e81
runtime.doInit(0x81607a0)
	/root/go.master/src/runtime/proc.go:5554 +0x5b fp=0x888afb0 sp=0x888af98 pc=0x8085e4b
runtime.doInit(0x815f530)
	/root/go.master/src/runtime/proc.go:5554 +0x5b fp=0x888afc8 sp=0x888afb0 pc=0x8085e4b
runtime.main()
	/root/go.master/src/runtime/proc.go:191 +0x185 fp=0x888aff0 sp=0x888afc8 pc=0x8079cc5
runtime.goexit()
	/root/go.master/src/runtime/asm_386.s:1333 +0x1 fp=0x888aff4 sp=0x888aff0 pc=0x80a3da1
fatal error: runtime: stack split at bad time

runtime stack:
runtime.throw(0x8103221, 0x20)
	/root/go.master/src/runtime/panic.go:1116 +0x6a fp=0xbff0c668 sp=0xbff0c654 pc=0x80779ba
runtime.newstack()
	/root/go.master/src/runtime/stack.go:965 +0xa90 fp=0xbff0c738 sp=0xbff0c668 pc=0x808dfc0
runtime.morestack()
	/root/go.master/src/runtime/asm_386.s:471 +0x7f fp=0xbff0c73c sp=0xbff0c738 pc=0x80a297f

goroutine 1 [running, locked to thread]:
runtime.casgstatus(0x88000e0, 0x2, 0x3)
	/root/go.master/src/runtime/proc.go:801 +0x58 fp=0x888ade0 sp=0x888adb0 pc=0x807b8d8
runtime.reentersyscall(0x80d68e5, 0x888ae0c)
	/root/go.master/src/runtime/proc.go:3027 +0x66 fp=0x888ae00 sp=0x888ade0 pc=0x80805a6
runtime.entersyscall()
	/root/go.master/src/runtime/proc.go:3076 +0x17 fp=0x888ae0c sp=0x888ae00 pc=0x80a1217
syscall.Syscall6(0x131, 0xffffff9c, 0x88a6000, 0x88a4000, 0x80, 0x0, 0x0, 0xa758010c, 0x0, 0x8069e02)
	/root/go.master/src/syscall/asm_linux_386.s:44 +0x5 fp=0x888ae10 sp=0x888ae0c pc=0x80d68e5
syscall.readlinkat(0xffffff9c, 0x80ff7ee, 0xe, 0x88a4000, 0x80, 0x80, 0x0, 0x0, 0x0)
	/root/go.master/src/syscall/zsyscall_linux_386.go:90 +0x123 fp=0x888ae6c sp=0x888ae10 pc=0x80d63b3
syscall.Readlink(0x80ff7ee, 0xe, 0x88a4000, 0x80, 0x80, 0x0, 0x0, 0x0)
	/root/go.master/src/syscall/syscall_linux.go:150 +0x75 fp=0x888aeac sp=0x888ae6c pc=0x80d5e35
os.Readlink(0x80ff7ee, 0xe, 0x0, 0x0, 0x0, 0x0)
	/root/go.master/src/os/file_unix.go:370 +0xba fp=0x888af18 sp=0x888aeac pc=0x80d990a
os.glob..func1(0x0, 0x0, 0x0, 0x0)
	/root/go.master/src/os/executable_procfs.go:29 +0x93 fp=0x888af5c sp=0x888af18 pc=0x80d9bf3
os.init()
	/root/go.master/src/os/executable_procfs.go:30 +0x198 fp=0x888af80 sp=0x888af5c pc=0x80d9e08
runtime.doInit(0x8160ae0)
	/root/go.master/src/runtime/proc.go:5559 +0x91 fp=0x888af98 sp=0x888af80 pc=0x8085e81
runtime.doInit(0x81607a0)
	/root/go.master/src/runtime/proc.go:5554 +0x5b fp=0x888afb0 sp=0x888af98 pc=0x8085e4b
runtime.doInit(0x815f530)
	/root/go.master/src/runtime/proc.go:5554 +0x5b fp=0x888afc8 sp=0x888afb0 pc=0x8085e4b
runtime.main()
	/root/go.master/src/runtime/proc.go:191 +0x185 fp=0x888aff0 sp=0x888afc8 pc=0x8079cc5
runtime.goexit()
	/root/go.master/src/runtime/asm_386.s:1333 +0x1 fp=0x888aff4 sp=0x888aff0 pc=0x80a3da1

goroutine 2 [force gc (idle)]:
runtime.gopark(0x81060c4, 0x81709f0, 0x8171411, 0x1)
	/root/go.master/src/runtime/proc.go:306 +0xaf fp=0x8828fc8 sp=0x8828fb4 pc=0x807a09f
runtime.goparkunlock(0x81709f0, 0x1411, 0x1)
	/root/go.master/src/runtime/proc.go:312 +0x45 fp=0x8828fdc sp=0x8828fc8 pc=0x807a145
runtime.forcegchelper()
	/root/go.master/src/runtime/proc.go:255 +0xc5 fp=0x8828ff0 sp=0x8828fdc pc=0x8079f65
runtime.goexit()
	/root/go.master/src/runtime/asm_386.s:1333 +0x1 fp=0x8828ff4 sp=0x8828ff0 pc=0x80a3da1
created by runtime.init.5
	/root/go.master/src/runtime/proc.go:243 +0x2b

goroutine 3 [GC sweep wait]:
runtime.gopark(0x81060c4, 0x8170b00, 0x806140c, 0x1)
	/root/go.master/src/runtime/proc.go:306 +0xaf fp=0x88297c4 sp=0x88297b0 pc=0x807a09f
runtime.goparkunlock(0x8170b00, 0x810140c, 0x1)
	/root/go.master/src/runtime/proc.go:312 +0x45 fp=0x88297d8 sp=0x88297c4 pc=0x807a145
runtime.bgsweep(0x881c040)
	/root/go.master/src/runtime/mgcsweep.go:163 +0x98 fp=0x88297e8 sp=0x88297d8 pc=0x8067ae8
runtime.goexit()
	/root/go.master/src/runtime/asm_386.s:1333 +0x1 fp=0x88297ec sp=0x88297e8 pc=0x80a3da1
created by runtime.gcenable
	/root/go.master/src/runtime/mgc.go:217 +0x4d

goroutine 4 [GC scavenge wait]:
runtime.gopark(0x81060c4, 0x8170aa0, 0x806140d, 0x1)
	/root/go.master/src/runtime/proc.go:306 +0xaf fp=0x8829f98 sp=0x8829f84 pc=0x807a09f
runtime.goparkunlock(0x8170aa0, 0x810140d, 0x1)
	/root/go.master/src/runtime/proc.go:312 +0x45 fp=0x8829fac sp=0x8829f98 pc=0x807a145
runtime.bgscavenge(0x881c040)
	/root/go.master/src/runtime/mgcscavenge.go:260 +0xc7 fp=0x8829fe8 sp=0x8829fac pc=0x8065fc7
runtime.goexit()
	/root/go.master/src/runtime/asm_386.s:1333 +0x1 fp=0x8829fec sp=0x8829fe8 pc=0x80a3da1
created by runtime.gcenable
	/root/go.master/src/runtime/mgc.go:218 +0x6b

Reason

I dive this issue then find this issue #38922 and this commit

The function named acquireLockRank at src/runtime/lockrank_on.go with go:nosplit , but at src/runtime/lockrank_off.go without go:nosplit. (GOEXPERIMENT="" in default )

Similarly, function lockWithRank/unlockWithRank/releaseLockRank/lockWithRankMayAcquire.

[gopherbot]

Change https://golang.org/cl/248878 mentions this issue: runtime: Fix panic if newstack at runtime.acquireLockRank

[prattmic]

cc @danscales @aclements

[ALTree]

@gopherbot, please backport to Go 1.15, as requested by prattmic.

[gopherbot]

Backport issue(s) opened: #40845 (for 1.15).

Remember to create the cherry-pick CL(s) as soon as the patch is submitted to master, according to https://golang.org/wiki/MinorReleases.

[chainhelen]

I have commited a pull request #40844 for solving this issue, please check it . Thx.