5l, 8l: pass stack frame size to morestack when needed
Shame on me: I fixed the same bug in 6l in 8691fcc6a66e
(https://golang.org/cl/2609041) and neglected
to look at 5l and 8l to see if they were affected.
On the positive side, the check I added in that CL is the
one that detected this bug.
Fixes #1457.
R=ken2
CC=golang-dev
https://golang.org/cl/3981052
diff --git a/src/cmd/5l/noop.c b/src/cmd/5l/noop.c
index 925984d..a9439c2 100644
--- a/src/cmd/5l/noop.c
+++ b/src/cmd/5l/noop.c
@@ -330,13 +330,14 @@
p->from.reg = 1;
p->reg = 2;
}
-
+
// MOVW.LO $autosize, R1
p = appendp(p);
p->as = AMOVW;
p->scond = C_SCOND_LO;
p->from.type = D_CONST;
- p->from.offset = 0;
+ /* 160 comes from 3 calls (3*8) 4 safes (4*8) and 104 guard */
+ p->from.offset = autosize+160;
p->to.type = D_REG;
p->to.reg = 1;
diff --git a/src/cmd/8l/pass.c b/src/cmd/8l/pass.c
index c3f1f47..878a73d 100644
--- a/src/cmd/8l/pass.c
+++ b/src/cmd/8l/pass.c
@@ -517,7 +517,7 @@
p->to.type = D_DX;
/* 160 comes from 3 calls (3*8) 4 safes (4*8) and 104 guard */
p->from.type = D_CONST;
- if(autoffset+160 > 4096)
+ if(autoffset+160+cursym->text->to.offset2 > 4096)
p->from.offset = (autoffset+160) & ~7LL;
p = appendp(p); // save arg size in AX
diff --git a/src/pkg/runtime/proc.c b/src/pkg/runtime/proc.c
index 62872d9..998cbc7 100644
--- a/src/pkg/runtime/proc.c
+++ b/src/pkg/runtime/proc.c
@@ -723,8 +723,10 @@
argsize = m->moreargsize;
g1 = m->curg;
- if(m->morebuf.sp < g1->stackguard - StackGuard)
- runtime·throw("split stack overflow");
+ if(m->morebuf.sp < g1->stackguard - StackGuard) {
+ runtime·printf("runtime: split stack overflow: %p < %p\n", m->morebuf.sp, g1->stackguard - StackGuard);
+ runtime·throw("runtime: split stack overflow");
+ }
reflectcall = framesize==1;
if(reflectcall)
diff --git a/test/stack.go b/test/stack.go
index 816b555..1fd5716 100644
--- a/test/stack.go
+++ b/test/stack.go
@@ -30,6 +30,32 @@
}
}
+func f0() {
+ // likely to make a new stack for f0,
+ // because the call to f1 puts 3000 bytes
+ // in our frame.
+ f1()
+}
+
+func f1() [3000]byte {
+ // likely to make a new stack for f1,
+ // because 3000 bytes were used by f0
+ // and we need 3000 more for the call
+ // to f2. if the call to morestack in f1
+ // does not pass the frame size, the new
+ // stack (default size 5k) will not be big
+ // enough for the frame, and the morestack
+ // check in f2 will die, if we get that far
+ // without faulting.
+ f2()
+ return [3000]byte{}
+}
+
+func f2() [3000]byte {
+ // just take up space
+ return [3000]byte{}
+}
+
var c = make(chan int)
var t T
var b = []byte{1, 2, 3, 4, 5, 6, 7, 8, 9, 10}
@@ -40,6 +66,7 @@
panic("bad []byte -> string")
}
go g(c, t)
+ f0()
s := <-c
if s != len(t) {
println("bad go", s)
