runtime: set libcall values for Solaris system calls

This lets SIGPROF signals get a useful traceback.
Without it we just see sysvicallN calling asmcgocall.

Updates #24142

Change-Id: I5dfe3add51f0c3a4cb1c98acb7738be6396214bc
Reviewed-on: https://go-review.googlesource.com/99617
Run-TryBot: Ian Lance Taylor <iant@golang.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Austin Clements <austin@google.com>

src/runtime/os_solaris.go

@@ -31,71 +31,190 @@ var asmsysvicall6 libcFunc
 
 //go:nosplit
 func sysvicall0(fn *libcFunc) uintptr {
+	// Leave caller's PC/SP around for traceback.
+	gp := getg()
+	var mp *m
+	if gp != nil {
+		mp = gp.m
+	}
+	if mp != nil {
+		mp.libcallg.set(gp)
+		mp.libcallpc = getcallerpc()
+		// sp must be the last, because once async cpu profiler finds
+		// all three values to be non-zero, it will use them
+		mp.libcallsp = getcallersp(unsafe.Pointer(&fn))
+	}
+
 	var libcall libcall
 	libcall.fn = uintptr(unsafe.Pointer(fn))
 	libcall.n = 0
 	libcall.args = uintptr(unsafe.Pointer(fn)) // it's unused but must be non-nil, otherwise crashes
 	asmcgocall(unsafe.Pointer(&asmsysvicall6), unsafe.Pointer(&libcall))
+	if mp != nil {
+		mp.libcallsp = 0
+	}
 	return libcall.r1
 }
 
 //go:nosplit
 func sysvicall1(fn *libcFunc, a1 uintptr) uintptr {
+	// Leave caller's PC/SP around for traceback.
+	gp := getg()
+	var mp *m
+	if gp != nil {
+		mp = gp.m
+	}
+	if mp != nil {
+		mp.libcallg.set(gp)
+		mp.libcallpc = getcallerpc()
+		// sp must be the last, because once async cpu profiler finds
+		// all three values to be non-zero, it will use them
+		mp.libcallsp = getcallersp(unsafe.Pointer(&fn))
+	}
+
 	var libcall libcall
 	libcall.fn = uintptr(unsafe.Pointer(fn))
 	libcall.n = 1
 	// TODO(rsc): Why is noescape necessary here and below?
 	libcall.args = uintptr(noescape(unsafe.Pointer(&a1)))
 	asmcgocall(unsafe.Pointer(&asmsysvicall6), unsafe.Pointer(&libcall))
+	if mp != nil {
+		mp.libcallsp = 0
+	}
 	return libcall.r1
 }
 
 //go:nosplit
 func sysvicall2(fn *libcFunc, a1, a2 uintptr) uintptr {
+	// Leave caller's PC/SP around for traceback.
+	gp := getg()
+	var mp *m
+	if gp != nil {
+		mp = gp.m
+	}
+	if mp != nil {
+		mp.libcallg.set(gp)
+		mp.libcallpc = getcallerpc()
+		// sp must be the last, because once async cpu profiler finds
+		// all three values to be non-zero, it will use them
+		mp.libcallsp = getcallersp(unsafe.Pointer(&fn))
+	}
+
 	var libcall libcall
 	libcall.fn = uintptr(unsafe.Pointer(fn))
 	libcall.n = 2
 	libcall.args = uintptr(noescape(unsafe.Pointer(&a1)))
 	asmcgocall(unsafe.Pointer(&asmsysvicall6), unsafe.Pointer(&libcall))
+	if mp != nil {
+		mp.libcallsp = 0
+	}
 	return libcall.r1
 }
 
 //go:nosplit
 func sysvicall3(fn *libcFunc, a1, a2, a3 uintptr) uintptr {
+	// Leave caller's PC/SP around for traceback.
+	gp := getg()
+	var mp *m
+	if gp != nil {
+		mp = gp.m
+	}
+	if mp != nil {
+		mp.libcallg.set(gp)
+		mp.libcallpc = getcallerpc()
+		// sp must be the last, because once async cpu profiler finds
+		// all three values to be non-zero, it will use them
+		mp.libcallsp = getcallersp(unsafe.Pointer(&fn))
+	}
+
 	var libcall libcall
 	libcall.fn = uintptr(unsafe.Pointer(fn))
 	libcall.n = 3
 	libcall.args = uintptr(noescape(unsafe.Pointer(&a1)))
 	asmcgocall(unsafe.Pointer(&asmsysvicall6), unsafe.Pointer(&libcall))
+	if mp != nil {
+		mp.libcallsp = 0
+	}
 	return libcall.r1
 }
 
 //go:nosplit
 func sysvicall4(fn *libcFunc, a1, a2, a3, a4 uintptr) uintptr {
+	// Leave caller's PC/SP around for traceback.
+	gp := getg()
+	var mp *m
+	if gp != nil {
+		mp = gp.m
+	}
+	if mp != nil {
+		mp.libcallg.set(gp)
+		mp.libcallpc = getcallerpc()
+		// sp must be the last, because once async cpu profiler finds
+		// all three values to be non-zero, it will use them
+		mp.libcallsp = getcallersp(unsafe.Pointer(&fn))
+	}
+
 	var libcall libcall
 	libcall.fn = uintptr(unsafe.Pointer(fn))
 	libcall.n = 4
 	libcall.args = uintptr(noescape(unsafe.Pointer(&a1)))
 	asmcgocall(unsafe.Pointer(&asmsysvicall6), unsafe.Pointer(&libcall))
+	if mp != nil {
+		mp.libcallsp = 0
+	}
 	return libcall.r1
 }
 
 //go:nosplit
 func sysvicall5(fn *libcFunc, a1, a2, a3, a4, a5 uintptr) uintptr {
+	// Leave caller's PC/SP around for traceback.
+	gp := getg()
+	var mp *m
+	if gp != nil {
+		mp = gp.m
+	}
+	if mp != nil {
+		mp.libcallg.set(gp)
+		mp.libcallpc = getcallerpc()
+		// sp must be the last, because once async cpu profiler finds
+		// all three values to be non-zero, it will use them
+		mp.libcallsp = getcallersp(unsafe.Pointer(&fn))
+	}
+
 	var libcall libcall
 	libcall.fn = uintptr(unsafe.Pointer(fn))
 	libcall.n = 5
 	libcall.args = uintptr(noescape(unsafe.Pointer(&a1)))
 	asmcgocall(unsafe.Pointer(&asmsysvicall6), unsafe.Pointer(&libcall))
+	if mp != nil {
+		mp.libcallsp = 0
+	}
 	return libcall.r1
 }
 
 //go:nosplit
 func sysvicall6(fn *libcFunc, a1, a2, a3, a4, a5, a6 uintptr) uintptr {
+	// Leave caller's PC/SP around for traceback.
+	gp := getg()
+	var mp *m
+	if gp != nil {
+		mp = gp.m
+	}
+	if mp != nil {
+		mp.libcallg.set(gp)
+		mp.libcallpc = getcallerpc()
+		// sp must be the last, because once async cpu profiler finds
+		// all three values to be non-zero, it will use them
+		mp.libcallsp = getcallersp(unsafe.Pointer(&fn))
+	}
+
 	var libcall libcall
 	libcall.fn = uintptr(unsafe.Pointer(fn))
 	libcall.n = 6
 	libcall.args = uintptr(noescape(unsafe.Pointer(&a1)))
 	asmcgocall(unsafe.Pointer(&asmsysvicall6), unsafe.Pointer(&libcall))
+	if mp != nil {
+		mp.libcallsp = 0
+	}
 	return libcall.r1
 }

src/runtime/proc.go

@@ -3697,7 +3697,7 @@ func sigprof(pc, sp, lr uintptr, gp *g, mp *m) {
 		// Normal traceback is impossible or has failed.
 		// See if it falls into several common cases.
 		n = 0
-		if GOOS == "windows" && mp.libcallg != 0 && mp.libcallpc != 0 && mp.libcallsp != 0 {
+		if (GOOS == "windows" || GOOS == "solaris") && mp.libcallg != 0 && mp.libcallpc != 0 && mp.libcallsp != 0 {
 			// Libcall, i.e. runtime syscall on windows.
 			// Collect Go stack that leads to the call.
 			n = gentraceback(mp.libcallpc, mp.libcallsp, 0, mp.libcallg.ptr(), 0, &stk[0], len(stk), nil, nil, 0)