code review 167055: Fix stack on FreeBSD / add stack check across the board

Fix stack on FreeBSD / add stack check across the board

FreeBSD was passing stk as the new thread's stack base, while
stk is the top of the stack in go. The added check should cause
a trap if this ever comes up in any new ports, or regresses
in current ones.

[dho, 2009-12-08 23:56:53]

Hello rsc (cc: golang-dev@googlegroups.com),

I'd like you to review the following change.

[rsc, 2009-12-09 00:37:30]

looks pretty good

http://codereview.appspot.com/167055/diff/11/12
File src/pkg/runtime/386/asm.s (right):

http://codereview.appspot.com/167055/diff/11/12#newcode329
src/pkg/runtime/386/asm.s:329: CMPL 0(AX), SP
g_stackbase

http://codereview.appspot.com/167055/diff/11/12#newcode332
src/pkg/runtime/386/asm.s:332: CMPL 8(AX), SP
g_stackguard (should be 4 not 8)

see also the comment about swapping
CMP args and using JHI in the next file.

http://codereview.appspot.com/167055/diff/11/13
File src/pkg/runtime/amd64/asm.s (right):

http://codereview.appspot.com/167055/diff/11/13#newcode310
src/pkg/runtime/amd64/asm.s:310: JLO 2(PC)
just to mimic the linker, let's make this

CMPQ SP, g_stackguard(g)
JHI 2(PC)

http://codereview.appspot.com/167055/diff/11/14
File src/pkg/runtime/darwin/386/sys.s (right):

http://codereview.appspot.com/167055/diff/11/14#newcode154
src/pkg/runtime/darwin/386/sys.s:154: CALL	stackcheck(SB)
move down 2 lines
let m get set too.
also add a comment

CALL stackcheck(SB) // smashes AX

http://codereview.appspot.com/167055/diff/11/16
File src/pkg/runtime/freebsd/386/sys.s (right):

http://codereview.appspot.com/167055/diff/11/16#newcode37
src/pkg/runtime/freebsd/386/sys.s:37: CALL	stackcheck(SB)
move down 1 line

http://codereview.appspot.com/167055/diff/11/18
File src/pkg/runtime/freebsd/thread.c (right):

http://codereview.appspot.com/167055/diff/11/18#newcode143
src/pkg/runtime/freebsd/thread.c:143: param.stack_size = ((byte*)stk -
(byte*)g->stackbase);
can drop outer parens

http://codereview.appspot.com/167055/diff/11/19
File src/pkg/runtime/linux/386/sys.s (right):

http://codereview.appspot.com/167055/diff/11/19#newcode153
src/pkg/runtime/linux/386/sys.s:153: CALL	stackcheck(SB)
move down 1 line
add // smashes AX comment

[dho, 2009-12-09 00:44:22]

Hello rsc (cc: golang-dev@googlegroups.com),

I'd like you to review the following change.

[rsc, 2009-12-09 00:52:14]

LGTM

thanks

[rsc, 2009-12-09 02:19:32]

*** Submitted as http://code.google.com/p/go/source/detail?r=c3a343e57091 ***

Fix stack on FreeBSD / add stack check across the board

FreeBSD was passing stk as the new thread's stack base, while
stk is the top of the stack in go. The added check should cause
a trap if this ever comes up in any new ports, or regresses
in current ones.

R=rsc
CC=golang-dev
http://codereview.appspot.com/167055

Committer: Russ Cox <rsc@golang.org>