add stub routines stackalloc() and stackfree().
run oldstack on g0's stack, just like newstack does,
so that oldstack can free the old stack.
R=r
DELTA=53 (44 added, 0 deleted, 9 changed)
OCL=20404
CL=20433
diff --git a/src/runtime/Makefile b/src/runtime/Makefile
index cd1cf28..da12c2c 100644
--- a/src/runtime/Makefile
+++ b/src/runtime/Makefile
@@ -25,6 +25,7 @@
print.$O\
rune.$O\
proc.$O\
+ stack.$O\
string.$O\
symtab.$O\
sys_file.$O\
diff --git a/src/runtime/proc.c b/src/runtime/proc.c
index 4a61358..fa30c1e 100644
--- a/src/runtime/proc.c
+++ b/src/runtime/proc.c
@@ -567,6 +567,7 @@
Stktop *top;
uint32 siz2;
byte *sp;
+ uint64 oldsp, oldpc, oldbase, oldguard;
// printf("oldstack m->cret=%p\n", m->cret);
@@ -581,16 +582,37 @@
mcpy(top->oldsp+16, sp, siz2);
}
- // call no more functions after this point - stackguard disagrees with SP
- m->curg->stackbase = top->oldbase;
- m->curg->stackguard = top->oldguard;
- m->morestack.SP = top->oldsp+8;
- m->morestack.PC = (byte*)(*(uint64*)(top->oldsp+8));
+ oldsp = (uint64)top->oldsp + 8;
+ oldpc = *(uint64*)(top->oldsp + 8);
+ oldbase = (uint64)top->oldbase;
+ oldguard = (uint64)top->oldguard;
+ stackfree((byte*)m->curg->stackguard - 512 - 160);
+
+ m->curg->stackbase = (byte*)oldbase;
+ m->curg->stackguard = (byte*)oldguard;
+ m->morestack.SP = (byte*)oldsp;
+ m->morestack.PC = (byte*)oldpc;
+
+ // These two lines must happen in sequence;
+ // once g has been changed, must switch to g's stack
+ // before calling any non-assembly functions.
+ // TODO(rsc): Perhaps make the new g a parameter
+ // to gogoret and setspgoto, so that g is never
+ // explicitly assigned to without also setting
+ // the stack pointer.
+ g = m->curg;
gogoret(&m->morestack, m->cret);
}
void
+lessstack(void)
+{
+ g = m->g0;
+ setspgoto(m->sched.SP, oldstack, nil);
+}
+
+void
newstack(void)
{
int32 siz1, siz2;
@@ -611,7 +633,7 @@
if(siz1 < 4096)
siz1 = 4096;
- stk = mal(siz1 + 1024);
+ stk = stackalloc(siz1 + 1024);
stk += 512;
top = (Stktop*)(stk+siz1-sizeof(*top));
@@ -658,3 +680,4 @@
*(int32*)234 = 123; // never return
}
+
diff --git a/src/runtime/rt0_amd64.s b/src/runtime/rt0_amd64.s
index ad86c56..73e9251 100644
--- a/src/runtime/rt0_amd64.s
+++ b/src/runtime/rt0_amd64.s
@@ -42,7 +42,7 @@
CALL sys·newproc(SB)
POPQ AX
POPQ AX
-
+
// start this M
CALL mstart(SB)
@@ -89,10 +89,10 @@
* support for morestack
*/
-// return point when leaving new stack. save AX, jmp to oldstack to switch back
+// return point when leaving new stack. save AX, jmp to lessstack to switch back
TEXT retfromnewstack(SB), 7, $0
MOVQ AX, 16(R14) // save AX in m->cret
- MOVQ $oldstack(SB), AX
+ MOVQ $lessstack(SB), AX
JMP AX
// gogo, returning 2nd arg instead of 1
diff --git a/src/runtime/runtime.h b/src/runtime/runtime.h
index e37786e..a0cbac3 100644
--- a/src/runtime/runtime.h
+++ b/src/runtime/runtime.h
@@ -277,6 +277,8 @@
void minit(void);
Func* findfunc(uint64);
int32 funcline(Func*, uint64);
+void* stackalloc(uint32);
+void stackfree(void*);
/*
* mutual exclusion locks. in the uncontended case,
diff --git a/src/runtime/stack.c b/src/runtime/stack.c
new file mode 100644
index 0000000..a4eeedc
--- /dev/null
+++ b/src/runtime/stack.c
@@ -0,0 +1,19 @@
+// 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.
+
+#include "runtime.h"
+
+// Stubs for stack management.
+// In a separate file so they can be overridden during testing of gc.
+
+void*
+stackalloc(uint32 n)
+{
+ return mal(n);
+}
+
+void
+stackfree(void*)
+{
+}
