1 // Copyright 2014 The Go Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style 3 // license that can be found in the LICENSE file. 4 5 // +build ppc64 ppc64le 6 7 package runtime 8 9 import "unsafe" 10 11 // adjust Gobuf as if it executed a call to fn with context ctxt 12 // and then did an immediate Gosave. 13 func gostartcall(buf *gobuf, fn, ctxt unsafe.Pointer) { 14 if buf.lr != 0 { 15 throw("invalid use of gostartcall") 16 } 17 buf.lr = buf.pc 18 buf.pc = uintptr(fn) 19 buf.ctxt = ctxt 20 } 21 22 // Called to rewind context saved during morestack back to beginning of function. 23 // To help us, the linker emits a jmp back to the beginning right after the 24 // call to morestack. We just have to decode and apply that jump. 25 func rewindmorestack(buf *gobuf) { 26 var inst uint32 27 if buf.pc&3 == 0 && buf.pc != 0 { 28 inst = *(*uint32)(unsafe.Pointer(buf.pc)) 29 if inst>>26 == 18 && inst&3 == 0 { 30 //print("runtime: rewind pc=", hex(buf.pc), " to pc=", hex(uintptr(buf.pc + int32(inst<<6)>>6)), "\n"); 31 buf.pc += uintptr(int32(inst<<6) >> 6) 32 return 33 } 34 } 35 print("runtime: pc=", hex(buf.pc), " ", hex(inst), "\n") 36 throw("runtime: misuse of rewindmorestack") 37 } 38
