// symbolizer.
		pcBuf[0] = logicalStackSentinel
		if getg() == gp {
			nstk += callers(skip+1, pcBuf[1:])
		} else if gp != nil {
			nstk += gcallers(gp, skip, pcBuf[1:])
		}
	} else {
		// Fast path: Unwind using frame pointers.
		pcBuf[0] = uintptr(skip)
		if getg() == gp {
			nstk += fpTracebackPCs(unsafe.Pointer(getfp()), pcBuf[1:])
		} else if gp != nil {
			// Three cases:

		// it may hit stack split that is not expected here.
		if gp != nil {
			setg(nil)
		}
		badsignal(uintptr(sig), c)
		// Restore g
		if gp != nil {
			setg(gp)
		}
		return
	}

	setg(gp.m.gsignal)

	// If some non-Go code called sigaltstack, adjust.
	var gsignalStack gsignalStack

	if goarch.IsWasm == 0 && stringslite.HasPrefix(funcname(findfunc(pc)), "runtime.") {
		// Note: wasm can't tail call, so we can't get the original caller's pc.
		throw(msg)
	}
	// TODO: is this redundant? How could we be in malloc
	// but not in the runtime? runtime/internal/*, maybe?
	gp := getg()
	if gp != nil && gp.m != nil && gp.m.mallocing != 0 {
		throw(msg)
	}
}

	"internal/goarch"
	"internal/stringslite"
	"unsafe"
)

// May run during STW, so write barriers are not allowed.
//
//go:nowritebarrierrec
func sighandler(_ureg *ureg, note *byte, gp *g) int {
	gsignal := getg()
	mp := gsignal.m

	var t sigTabT
	var docrash bool
	var sig int
	var flags int
	var level int32

	c := &sigctxt{_ureg}
	notestr := gostringnocopy(note)

// anyhow for values on the stack. Just ignore msanread when running
// on the system stack. The other msan functions are fine.
//
//go:linkname msanread
//go:nosplit
func msanread(addr unsafe.Pointer, sz uintptr) {
	gp := getg()
	if gp == nil || gp.m == nil || gp == gp.m.g0 || gp == gp.m.gsignal {
		return
	}
	domsanread(addr, sz)
}

//go:noescape
func domsanread(addr unsafe.Pointer, sz uintptr)

//go:linkname msanwrite

			lock(&rw.rLock)
			if rw.readerPass > 0 {
				// Writer finished.
				rw.readerPass -= 1
				unlock(&rw.rLock)
			} else {
				// Queue this reader to be woken by
				// the writer.
				m := getg().m
				m.schedlink = rw.readers
				rw.readers.set(m)
				unlock(&rw.rLock)
				notesleep(&m.park)
				noteclear(&m.park)
			}
		})
	}
}

// runlock undoes a single rlock call on rw.

	}
	if s := readgstatus(gp); s&_Gscan == 0 {
		// We don't own the stack via _Gscan. We could still
		// own it if this is our own user G and we're on the
		// system stack.
		if !(gp == getg().m.curg && getg() != getg().m.curg && s == _Grunning) {
			// We don't own the stack.
			throw("bad status in shrinkstack")
		}
	}
	if !isShrinkStackSafe(gp) {
		throw("shrinkstack at bad time")
	}

// This must be called with preemption enabled.
func gcAssistAlloc(gp *g) {
	// Don't assist in non-preemptible contexts. These are
	// generally fragile and won't allow the assist to block.
	if getg() == gp.m.g0 {
		return
	}
	if mp := getg().m; mp.locks > 0 || mp.preemptoff != "" {
		return
	}

	// This extremely verbose boolean indicates whether we've
	// entered mark assist from the perspective of the tracer.
	//

// See go.dev/issue/67401.
//
//go:linkname atomicwb
//go:nosplit
func atomicwb(ptr *unsafe.Pointer, new unsafe.Pointer) {
	slot := (*uintptr)(unsafe.Pointer(ptr))
	buf := getg().m.p.ptr().wbBuf.get2()
	buf[0] = *slot
	buf[1] = uintptr(new)
}

// atomicstorep performs *ptr = new atomically and invokes a write barrier.
//
//go:nosplit
func atomicstorep(ptr unsafe.Pointer, new unsafe.Pointer) {

	// procid. We need this for asynchronous preemption and it's
	// useful in debuggers.
	getg().m.procid = uint64(gettid())
}

// Called from dropm to undo the effect of an minit.
//
//go:nosplit
func unminit() {
	unminitSignals()
	getg().m.procid = 0
}

// Called from exitm, but not from drop, to undo the effect of thread-owned