| // Copyright 2009 The Go Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style |
| // license that can be found in the LICENSE file. |
| |
| package runtime |
| |
| import "unsafe" |
| |
| // The code in this file implements stack trace walking for all architectures. |
| // The most important fact about a given architecture is whether it uses a link register. |
| // On systems with link registers, the prologue for a non-leaf function stores the |
| // incoming value of LR at the bottom of the newly allocated stack frame. |
| // On systems without link registers, the architecture pushes a return PC during |
| // the call instruction, so the return PC ends up above the stack frame. |
| // In this file, the return PC is always called LR, no matter how it was found. |
| // |
| // To date, the opposite of a link register architecture is an x86 architecture. |
| // This code may need to change if some other kind of non-link-register |
| // architecture comes along. |
| // |
| // The other important fact is the size of a pointer: on 32-bit systems the LR |
| // takes up only 4 bytes on the stack, while on 64-bit systems it takes up 8 bytes. |
| // Typically this is ptrSize. |
| // |
| // As an exception, amd64p32 has ptrSize == 4 but the CALL instruction still |
| // stores an 8-byte return PC onto the stack. To accommodate this, we use regSize |
| // as the size of the architecture-pushed return PC. |
| // |
| // usesLR is defined below. ptrSize and regSize are defined in stubs.go. |
| |
| const usesLR = GOARCH != "amd64" && GOARCH != "amd64p32" && GOARCH != "386" |
| |
| var ( |
| // initialized in tracebackinit |
| deferprocPC uintptr |
| goexitPC uintptr |
| jmpdeferPC uintptr |
| mcallPC uintptr |
| morestackPC uintptr |
| mstartPC uintptr |
| newprocPC uintptr |
| rt0_goPC uintptr |
| sigpanicPC uintptr |
| |
| externalthreadhandlerp uintptr // initialized elsewhere |
| ) |
| |
| func tracebackinit() { |
| // Go variable initialization happens late during runtime startup. |
| // Instead of initializing the variables above in the declarations, |
| // schedinit calls this function so that the variables are |
| // initialized and available earlier in the startup sequence. |
| deferprocPC = funcPC(deferproc) |
| goexitPC = funcPC(goexit) |
| jmpdeferPC = funcPC(jmpdefer) |
| mcallPC = funcPC(mcall) |
| morestackPC = funcPC(morestack) |
| mstartPC = funcPC(mstart) |
| newprocPC = funcPC(newproc) |
| rt0_goPC = funcPC(rt0_go) |
| sigpanicPC = funcPC(sigpanic) |
| } |
| |
| // Traceback over the deferred function calls. |
| // Report them like calls that have been invoked but not started executing yet. |
| func tracebackdefers(gp *g, callback func(*stkframe, unsafe.Pointer) bool, v unsafe.Pointer) { |
| var frame stkframe |
| for d := gp._defer; d != nil; d = d.link { |
| fn := d.fn |
| if fn == nil { |
| // Defer of nil function. Args don't matter. |
| frame.pc = 0 |
| frame.fn = nil |
| frame.argp = 0 |
| frame.arglen = 0 |
| frame.argmap = nil |
| } else { |
| frame.pc = uintptr(fn.fn) |
| f := findfunc(frame.pc) |
| if f == nil { |
| print("runtime: unknown pc in defer ", hex(frame.pc), "\n") |
| gothrow("unknown pc") |
| } |
| frame.fn = f |
| frame.argp = uintptr(deferArgs(d)) |
| setArgInfo(&frame, f, true) |
| } |
| frame.continpc = frame.pc |
| if !callback((*stkframe)(noescape(unsafe.Pointer(&frame))), v) { |
| return |
| } |
| } |
| } |
| |
| // Generic traceback. Handles runtime stack prints (pcbuf == nil), |
| // the runtime.Callers function (pcbuf != nil), as well as the garbage |
| // collector (callback != nil). A little clunky to merge these, but avoids |
| // duplicating the code and all its subtlety. |
| func gentraceback(pc0 uintptr, sp0 uintptr, lr0 uintptr, gp *g, skip int, pcbuf *uintptr, max int, callback func(*stkframe, unsafe.Pointer) bool, v unsafe.Pointer, flags uint) int { |
| if goexitPC == 0 { |
| gothrow("gentraceback before goexitPC initialization") |
| } |
| g := getg() |
| if g == gp && g == g.m.curg { |
| // The starting sp has been passed in as a uintptr, and the caller may |
| // have other uintptr-typed stack references as well. |
| // If during one of the calls that got us here or during one of the |
| // callbacks below the stack must be grown, all these uintptr references |
| // to the stack will not be updated, and gentraceback will continue |
| // to inspect the old stack memory, which may no longer be valid. |
| // Even if all the variables were updated correctly, it is not clear that |
| // we want to expose a traceback that begins on one stack and ends |
| // on another stack. That could confuse callers quite a bit. |
| // Instead, we require that gentraceback and any other function that |
| // accepts an sp for the current goroutine (typically obtained by |
| // calling getcallersp) must not run on that goroutine's stack but |
| // instead on the g0 stack. |
| gothrow("gentraceback cannot trace user goroutine on its own stack") |
| } |
| gotraceback := gotraceback(nil) |
| if pc0 == ^uintptr(0) && sp0 == ^uintptr(0) { // Signal to fetch saved values from gp. |
| if gp.syscallsp != 0 { |
| pc0 = gp.syscallpc |
| sp0 = gp.syscallsp |
| if usesLR { |
| lr0 = 0 |
| } |
| } else { |
| pc0 = gp.sched.pc |
| sp0 = gp.sched.sp |
| if usesLR { |
| lr0 = gp.sched.lr |
| } |
| } |
| } |
| |
| nprint := 0 |
| var frame stkframe |
| frame.pc = pc0 |
| frame.sp = sp0 |
| if usesLR { |
| frame.lr = lr0 |
| } |
| waspanic := false |
| wasnewproc := false |
| printing := pcbuf == nil && callback == nil |
| _defer := gp._defer |
| |
| for _defer != nil && uintptr(_defer.argp) == _NoArgs { |
| _defer = _defer.link |
| } |
| |
| // If the PC is zero, it's likely a nil function call. |
| // Start in the caller's frame. |
| if frame.pc == 0 { |
| if usesLR { |
| frame.pc = *(*uintptr)(unsafe.Pointer(frame.sp)) |
| frame.lr = 0 |
| } else { |
| frame.pc = uintptr(*(*uintreg)(unsafe.Pointer(frame.sp))) |
| frame.sp += regSize |
| } |
| } |
| |
| f := findfunc(frame.pc) |
| if f == nil { |
| if callback != nil { |
| print("runtime: unknown pc ", hex(frame.pc), "\n") |
| gothrow("unknown pc") |
| } |
| return 0 |
| } |
| frame.fn = f |
| |
| n := 0 |
| for n < max { |
| // Typically: |
| // pc is the PC of the running function. |
| // sp is the stack pointer at that program counter. |
| // fp is the frame pointer (caller's stack pointer) at that program counter, or nil if unknown. |
| // stk is the stack containing sp. |
| // The caller's program counter is lr, unless lr is zero, in which case it is *(uintptr*)sp. |
| f = frame.fn |
| |
| // Found an actual function. |
| // Derive frame pointer and link register. |
| if frame.fp == 0 { |
| frame.fp = frame.sp + uintptr(funcspdelta(f, frame.pc)) |
| if !usesLR { |
| // On x86, call instruction pushes return PC before entering new function. |
| frame.fp += regSize |
| } |
| } |
| var flr *_func |
| if topofstack(f) { |
| frame.lr = 0 |
| flr = nil |
| } else if usesLR && f.entry == jmpdeferPC { |
| // jmpdefer modifies SP/LR/PC non-atomically. |
| // If a profiling interrupt arrives during jmpdefer, |
| // the stack unwind may see a mismatched register set |
| // and get confused. Stop if we see PC within jmpdefer |
| // to avoid that confusion. |
| // See golang.org/issue/8153. |
| if callback != nil { |
| gothrow("traceback_arm: found jmpdefer when tracing with callback") |
| } |
| frame.lr = 0 |
| } else { |
| if usesLR { |
| if n == 0 && frame.sp < frame.fp || frame.lr == 0 { |
| frame.lr = *(*uintptr)(unsafe.Pointer(frame.sp)) |
| } |
| } else { |
| if frame.lr == 0 { |
| frame.lr = uintptr(*(*uintreg)(unsafe.Pointer(frame.fp - regSize))) |
| } |
| } |
| flr = findfunc(frame.lr) |
| if flr == nil { |
| // This happens if you get a profiling interrupt at just the wrong time. |
| // In that context it is okay to stop early. |
| // But if callback is set, we're doing a garbage collection and must |
| // get everything, so crash loudly. |
| if callback != nil { |
| print("runtime: unexpected return pc for ", gofuncname(f), " called from ", hex(frame.lr), "\n") |
| gothrow("unknown caller pc") |
| } |
| } |
| } |
| |
| frame.varp = frame.fp |
| if !usesLR { |
| // On x86, call instruction pushes return PC before entering new function. |
| frame.varp -= regSize |
| } |
| |
| // Derive size of arguments. |
| // Most functions have a fixed-size argument block, |
| // so we can use metadata about the function f. |
| // Not all, though: there are some variadic functions |
| // in package runtime and reflect, and for those we use call-specific |
| // metadata recorded by f's caller. |
| if callback != nil || printing { |
| frame.argp = frame.fp |
| if usesLR { |
| frame.argp += ptrSize |
| } |
| setArgInfo(&frame, f, callback != nil) |
| } |
| |
| // Determine function SP where deferproc would find its arguments. |
| var sparg uintptr |
| if usesLR { |
| // On link register architectures, that's the standard bottom-of-stack plus 1 word |
| // for the saved LR. If the previous frame was a direct call to newproc/deferproc, |
| // however, the SP is three words lower than normal. |
| // If the function has no frame at all - perhaps it just started, or perhaps |
| // it is a leaf with no local variables - then we cannot possibly find its |
| // SP in a defer, and we might confuse its SP for its caller's SP, so |
| // leave sparg=0 in that case. |
| if frame.fp != frame.sp { |
| sparg = frame.sp + regSize |
| if wasnewproc { |
| sparg += 3 * regSize |
| } |
| } |
| } else { |
| // On x86 that's the standard bottom-of-stack, so SP exactly. |
| // If the previous frame was a direct call to newproc/deferproc, however, |
| // the SP is two words lower than normal. |
| sparg = frame.sp |
| if wasnewproc { |
| sparg += 2 * ptrSize |
| } |
| } |
| |
| // Determine frame's 'continuation PC', where it can continue. |
| // Normally this is the return address on the stack, but if sigpanic |
| // is immediately below this function on the stack, then the frame |
| // stopped executing due to a trap, and frame.pc is probably not |
| // a safe point for looking up liveness information. In this panicking case, |
| // the function either doesn't return at all (if it has no defers or if the |
| // defers do not recover) or it returns from one of the calls to |
| // deferproc a second time (if the corresponding deferred func recovers). |
| // It suffices to assume that the most recent deferproc is the one that |
| // returns; everything live at earlier deferprocs is still live at that one. |
| frame.continpc = frame.pc |
| if waspanic { |
| if _defer != nil && _defer.argp == sparg { |
| frame.continpc = _defer.pc |
| } else { |
| frame.continpc = 0 |
| } |
| } |
| |
| // Unwind our local defer stack past this frame. |
| for _defer != nil && (_defer.argp == sparg || _defer.argp == _NoArgs) { |
| _defer = _defer.link |
| } |
| |
| if skip > 0 { |
| skip-- |
| goto skipped |
| } |
| |
| if pcbuf != nil { |
| (*[1 << 20]uintptr)(unsafe.Pointer(pcbuf))[n] = frame.pc |
| } |
| if callback != nil { |
| if !callback((*stkframe)(noescape(unsafe.Pointer(&frame))), v) { |
| return n |
| } |
| } |
| if printing { |
| if (flags&_TraceRuntimeFrames) != 0 || showframe(f, gp) { |
| // Print during crash. |
| // main(0x1, 0x2, 0x3) |
| // /home/rsc/go/src/runtime/x.go:23 +0xf |
| // |
| tracepc := frame.pc // back up to CALL instruction for funcline. |
| if (n > 0 || flags&_TraceTrap == 0) && frame.pc > f.entry && !waspanic { |
| tracepc-- |
| } |
| print(gofuncname(f), "(") |
| argp := (*[100]uintptr)(unsafe.Pointer(frame.argp)) |
| for i := uintptr(0); i < frame.arglen/ptrSize; i++ { |
| if i >= 10 { |
| print(", ...") |
| break |
| } |
| if i != 0 { |
| print(", ") |
| } |
| print(hex(argp[i])) |
| } |
| print(")\n") |
| var file string |
| line := funcline(f, tracepc, &file) |
| print("\t", file, ":", line) |
| if frame.pc > f.entry { |
| print(" +", hex(frame.pc-f.entry)) |
| } |
| if g.m.throwing > 0 && gp == g.m.curg || gotraceback >= 2 { |
| print(" fp=", hex(frame.fp), " sp=", hex(frame.sp)) |
| } |
| print("\n") |
| nprint++ |
| } |
| } |
| n++ |
| |
| skipped: |
| waspanic = f.entry == sigpanicPC |
| wasnewproc = f.entry == newprocPC || f.entry == deferprocPC |
| |
| // Do not unwind past the bottom of the stack. |
| if flr == nil { |
| break |
| } |
| |
| // Unwind to next frame. |
| frame.fn = flr |
| frame.pc = frame.lr |
| frame.lr = 0 |
| frame.sp = frame.fp |
| frame.fp = 0 |
| frame.argmap = nil |
| |
| // On link register architectures, sighandler saves the LR on stack |
| // before faking a call to sigpanic. |
| if usesLR && waspanic { |
| x := *(*uintptr)(unsafe.Pointer(frame.sp)) |
| frame.sp += ptrSize |
| f = findfunc(frame.pc) |
| frame.fn = f |
| if f == nil { |
| frame.pc = x |
| } else if f.frame == 0 { |
| frame.lr = x |
| } |
| } |
| } |
| |
| if pcbuf == nil && callback == nil { |
| n = nprint |
| } |
| |
| // If callback != nil, we're being called to gather stack information during |
| // garbage collection or stack growth. In that context, require that we used |
| // up the entire defer stack. If not, then there is a bug somewhere and the |
| // garbage collection or stack growth may not have seen the correct picture |
| // of the stack. Crash now instead of silently executing the garbage collection |
| // or stack copy incorrectly and setting up for a mysterious crash later. |
| // |
| // Note that panic != nil is okay here: there can be leftover panics, |
| // because the defers on the panic stack do not nest in frame order as |
| // they do on the defer stack. If you have: |
| // |
| // frame 1 defers d1 |
| // frame 2 defers d2 |
| // frame 3 defers d3 |
| // frame 4 panics |
| // frame 4's panic starts running defers |
| // frame 5, running d3, defers d4 |
| // frame 5 panics |
| // frame 5's panic starts running defers |
| // frame 6, running d4, garbage collects |
| // frame 6, running d2, garbage collects |
| // |
| // During the execution of d4, the panic stack is d4 -> d3, which |
| // is nested properly, and we'll treat frame 3 as resumable, because we |
| // can find d3. (And in fact frame 3 is resumable. If d4 recovers |
| // and frame 5 continues running, d3, d3 can recover and we'll |
| // resume execution in (returning from) frame 3.) |
| // |
| // During the execution of d2, however, the panic stack is d2 -> d3, |
| // which is inverted. The scan will match d2 to frame 2 but having |
| // d2 on the stack until then means it will not match d3 to frame 3. |
| // This is okay: if we're running d2, then all the defers after d2 have |
| // completed and their corresponding frames are dead. Not finding d3 |
| // for frame 3 means we'll set frame 3's continpc == 0, which is correct |
| // (frame 3 is dead). At the end of the walk the panic stack can thus |
| // contain defers (d3 in this case) for dead frames. The inversion here |
| // always indicates a dead frame, and the effect of the inversion on the |
| // scan is to hide those dead frames, so the scan is still okay: |
| // what's left on the panic stack are exactly (and only) the dead frames. |
| // |
| // We require callback != nil here because only when callback != nil |
| // do we know that gentraceback is being called in a "must be correct" |
| // context as opposed to a "best effort" context. The tracebacks with |
| // callbacks only happen when everything is stopped nicely. |
| // At other times, such as when gathering a stack for a profiling signal |
| // or when printing a traceback during a crash, everything may not be |
| // stopped nicely, and the stack walk may not be able to complete. |
| // It's okay in those situations not to use up the entire defer stack: |
| // incomplete information then is still better than nothing. |
| if callback != nil && n < max && _defer != nil { |
| if _defer != nil { |
| print("runtime: g", gp.goid, ": leftover defer argp=", hex(_defer.argp), " pc=", hex(_defer.pc), "\n") |
| } |
| for _defer = gp._defer; _defer != nil; _defer = _defer.link { |
| print("\tdefer ", _defer, " argp=", hex(_defer.argp), " pc=", hex(_defer.pc), "\n") |
| } |
| gothrow("traceback has leftover defers") |
| } |
| |
| return n |
| } |
| |
| func setArgInfo(frame *stkframe, f *_func, needArgMap bool) { |
| frame.arglen = uintptr(f.args) |
| if needArgMap && f.args == _ArgsSizeUnknown { |
| // Extract argument bitmaps for reflect stubs from the calls they made to reflect. |
| switch gofuncname(f) { |
| case "reflect.makeFuncStub", "reflect.methodValueCall": |
| arg0 := frame.sp |
| if usesLR { |
| arg0 += ptrSize |
| } |
| fn := *(**[2]uintptr)(unsafe.Pointer(arg0)) |
| if fn[0] != f.entry { |
| print("runtime: confused by ", gofuncname(f), "\n") |
| gothrow("reflect mismatch") |
| } |
| bv := (*bitvector)(unsafe.Pointer(fn[1])) |
| frame.arglen = uintptr(bv.n / 2 * ptrSize) |
| frame.argmap = bv |
| } |
| } |
| } |
| |
| func printcreatedby(gp *g) { |
| // Show what created goroutine, except main goroutine (goid 1). |
| pc := gp.gopc |
| f := findfunc(pc) |
| if f != nil && showframe(f, gp) && gp.goid != 1 { |
| print("created by ", gofuncname(f), "\n") |
| tracepc := pc // back up to CALL instruction for funcline. |
| if pc > f.entry { |
| tracepc -= _PCQuantum |
| } |
| var file string |
| line := funcline(f, tracepc, &file) |
| print("\t", file, ":", line) |
| if pc > f.entry { |
| print(" +", hex(pc-f.entry)) |
| } |
| print("\n") |
| } |
| } |
| |
| func traceback(pc uintptr, sp uintptr, lr uintptr, gp *g) { |
| traceback1(pc, sp, lr, gp, 0) |
| } |
| |
| // tracebacktrap is like traceback but expects that the PC and SP were obtained |
| // from a trap, not from gp->sched or gp->syscallpc/gp->syscallsp or getcallerpc/getcallersp. |
| // Because they are from a trap instead of from a saved pair, |
| // the initial PC must not be rewound to the previous instruction. |
| // (All the saved pairs record a PC that is a return address, so we |
| // rewind it into the CALL instruction.) |
| func tracebacktrap(pc uintptr, sp uintptr, lr uintptr, gp *g) { |
| traceback1(pc, sp, lr, gp, _TraceTrap) |
| } |
| |
| func traceback1(pc uintptr, sp uintptr, lr uintptr, gp *g, flags uint) { |
| var n int |
| if readgstatus(gp)&^_Gscan == _Gsyscall { |
| // Override registers if blocked in system call. |
| pc = gp.syscallpc |
| sp = gp.syscallsp |
| flags &^= _TraceTrap |
| } |
| // Print traceback. By default, omits runtime frames. |
| // If that means we print nothing at all, repeat forcing all frames printed. |
| n = gentraceback(pc, sp, lr, gp, 0, nil, _TracebackMaxFrames, nil, nil, flags) |
| if n == 0 && (flags&_TraceRuntimeFrames) == 0 { |
| n = gentraceback(pc, sp, lr, gp, 0, nil, _TracebackMaxFrames, nil, nil, flags|_TraceRuntimeFrames) |
| } |
| if n == _TracebackMaxFrames { |
| print("...additional frames elided...\n") |
| } |
| printcreatedby(gp) |
| } |
| |
| func callers(skip int, pcbuf *uintptr, m int) int { |
| sp := getcallersp(unsafe.Pointer(&skip)) |
| pc := uintptr(getcallerpc(unsafe.Pointer(&skip))) |
| var n int |
| onM(func() { |
| n = gentraceback(pc, sp, 0, getg(), skip, pcbuf, m, nil, nil, 0) |
| }) |
| return n |
| } |
| |
| func gcallers(gp *g, skip int, pcbuf *uintptr, m int) int { |
| return gentraceback(^uintptr(0), ^uintptr(0), 0, gp, skip, pcbuf, m, nil, nil, 0) |
| } |
| |
| func showframe(f *_func, gp *g) bool { |
| g := getg() |
| if g.m.throwing > 0 && gp != nil && (gp == g.m.curg || gp == g.m.caughtsig) { |
| return true |
| } |
| traceback := gotraceback(nil) |
| name := gostringnocopy(funcname(f)) |
| |
| // Special case: always show runtime.panic frame, so that we can |
| // see where a panic started in the middle of a stack trace. |
| // See golang.org/issue/5832. |
| if name == "runtime.panic" { |
| return true |
| } |
| |
| return traceback > 1 || f != nil && contains(name, ".") && (!hasprefix(name, "runtime.") || isExportedRuntime(name)) |
| } |
| |
| // isExportedRuntime reports whether name is an exported runtime function. |
| // It is only for runtime functions, so ASCII A-Z is fine. |
| func isExportedRuntime(name string) bool { |
| const n = len("runtime.") |
| return len(name) > n && name[:n] == "runtime." && 'A' <= name[n] && name[n] <= 'Z' |
| } |
| |
| var gStatusStrings = [...]string{ |
| _Gidle: "idle", |
| _Grunnable: "runnable", |
| _Grunning: "running", |
| _Gsyscall: "syscall", |
| _Gwaiting: "waiting", |
| _Gdead: "dead", |
| _Genqueue: "enqueue", |
| _Gcopystack: "copystack", |
| } |
| |
| var gScanStatusStrings = [...]string{ |
| 0: "scan", |
| _Grunnable: "scanrunnable", |
| _Grunning: "scanrunning", |
| _Gsyscall: "scansyscall", |
| _Gwaiting: "scanwaiting", |
| _Gdead: "scandead", |
| _Genqueue: "scanenqueue", |
| } |
| |
| func goroutineheader(gp *g) { |
| gpstatus := readgstatus(gp) |
| |
| // Basic string status |
| var status string |
| if 0 <= gpstatus && gpstatus < uint32(len(gStatusStrings)) { |
| status = gStatusStrings[gpstatus] |
| } else if gpstatus&_Gscan != 0 && 0 <= gpstatus&^_Gscan && gpstatus&^_Gscan < uint32(len(gStatusStrings)) { |
| status = gStatusStrings[gpstatus&^_Gscan] |
| } else { |
| status = "???" |
| } |
| |
| // Override. |
| if (gpstatus == _Gwaiting || gpstatus == _Gscanwaiting) && gp.waitreason != "" { |
| status = gp.waitreason |
| } |
| |
| // approx time the G is blocked, in minutes |
| var waitfor int64 |
| gpstatus &^= _Gscan // drop the scan bit |
| if (gpstatus == _Gwaiting || gpstatus == _Gsyscall) && gp.waitsince != 0 { |
| waitfor = (nanotime() - gp.waitsince) / 60e9 |
| } |
| print("goroutine ", gp.goid, " [", status) |
| if waitfor >= 1 { |
| print(", ", waitfor, " minutes") |
| } |
| if gp.lockedm != nil { |
| print(", locked to thread") |
| } |
| print("]:\n") |
| } |
| |
| func tracebackothers(me *g) { |
| level := gotraceback(nil) |
| |
| // Show the current goroutine first, if we haven't already. |
| g := getg() |
| gp := g.m.curg |
| if gp != nil && gp != me { |
| print("\n") |
| goroutineheader(gp) |
| traceback(^uintptr(0), ^uintptr(0), 0, gp) |
| } |
| |
| lock(&allglock) |
| for _, gp := range allgs { |
| if gp == me || gp == g.m.curg || readgstatus(gp) == _Gdead || gp.issystem && level < 2 { |
| continue |
| } |
| print("\n") |
| goroutineheader(gp) |
| if readgstatus(gp)&^_Gscan == _Grunning { |
| print("\tgoroutine running on other thread; stack unavailable\n") |
| printcreatedby(gp) |
| } else { |
| traceback(^uintptr(0), ^uintptr(0), 0, gp) |
| } |
| } |
| unlock(&allglock) |
| } |
| |
| // Does f mark the top of a goroutine stack? |
| func topofstack(f *_func) bool { |
| pc := f.entry |
| return pc == goexitPC || |
| pc == mstartPC || |
| pc == mcallPC || |
| pc == morestackPC || |
| pc == rt0_goPC || |
| externalthreadhandlerp != 0 && pc == externalthreadhandlerp |
| } |