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
https://golang.org/cl/167055

diff --git a/src/pkg/runtime/386/asm.s b/src/pkg/runtime/386/asm.s
index bd88f0fdc5a964437501d4c2733739938c4da735..7ec62161d93d3f5cf7178ebd1aeba63eaf0a0ccf 100644 (file)
--- a/src/pkg/runtime/386/asm.s
+++ b/src/pkg/runtime/386/asm.s
@@ -323,6 +323,17 @@ TEXT       runcgo(SB),7,$16
        MOVL    4(SP), SP
        RET
 
+// check that SP is in range [g->stackbase, g->stackguard)
+TEXT stackcheck(SB), 7, $0
+       MOVL g, AX
+       CMPL g_stackbase(AX), SP
+       JHI 2(PC)
+       INT $3
+       CMPL SP, g_stackguard(AX)
+       JHI 2(PC)
+       INT $3
+       RET
+
 
 GLOBL m0(SB), $1024
 GLOBL g0(SB), $1024

diff --git a/src/pkg/runtime/amd64/asm.s b/src/pkg/runtime/amd64/asm.s
index aee4e9a3f74936785d1af5beab18bb1524081850..3bd63ad15b164bd5154807122915674f6ac6754b 100644 (file)
--- a/src/pkg/runtime/amd64/asm.s
+++ b/src/pkg/runtime/amd64/asm.s
@@ -301,3 +301,13 @@ TEXT runcgo(SB),7,$32
        MOVQ    8(SP), SP
        RET
 
+// check that SP is in range [g->stackbase, g->stackguard)
+TEXT stackcheck(SB), 7, $0
+       CMPQ g_stackbase(g), SP
+       JHI 2(PC)
+       INT $3
+       CMPQ SP, g_stackguard(g)
+       JHI 2(PC)
+       INT $3
+       RET
+

diff --git a/src/pkg/runtime/darwin/386/sys.s b/src/pkg/runtime/darwin/386/sys.s
index 445f5300288d4ba6026fc88a81a082e08f8f1e47..38459447f89cb83810de62938046e65c2923598c 100644 (file)
--- a/src/pkg/runtime/darwin/386/sys.s
+++ b/src/pkg/runtime/darwin/386/sys.s
@@ -153,6 +153,7 @@ TEXT bsdthread_start(SB),7,$0
        MOVL    AX, g
        MOVL    DX, m
        MOVL    BX, m_procid(DX)        // m->procid = thread port (for debuggers)
+       CALL    stackcheck(SB)          // smashes AX
        CALL    CX      // fn()
        CALL    exit1(SB)
        RET

diff --git a/src/pkg/runtime/freebsd/386/sys.s b/src/pkg/runtime/freebsd/386/sys.s
index 1c0eaead5b08e9763bdaadcbe5d3d77ab5108d43..651ccb2348dedb559df57e28cfe707ff5148d209 100644 (file)
--- a/src/pkg/runtime/freebsd/386/sys.s
+++ b/src/pkg/runtime/freebsd/386/sys.s
@@ -9,13 +9,13 @@
 #include "386/asm.h"
        
 TEXT sys_umtx_op(SB),7,$-4
-       MOVL $454, AX
-       INT $0x80
+       MOVL    $454, AX
+       INT     $0x80
        RET
 
 TEXT thr_new(SB),7,$-4
-       MOVL $455, AX
-       INT $0x80
+       MOVL    $455, AX
+       INT     $0x80
        RET
 
 TEXT thr_start(SB),7,$0
@@ -33,10 +33,11 @@ TEXT thr_start(SB),7,$0
        POPL    AX
        POPL    AX
        POPAL
-       MOVL BX, g
-       MOVL AX, m
-       CALL mstart(SB)
-       MOVL 0, AX                      // crash (not reached)
+       MOVL    BX, g
+       MOVL    AX, m
+       CALL    stackcheck(SB)          // smashes AX
+       CALL    mstart(SB)
+       MOVL    0, AX                   // crash (not reached)
 
 // Exit the entire program (like C exit)
 TEXT exit(SB),7,$-4

diff --git a/src/pkg/runtime/freebsd/amd64/sys.s b/src/pkg/runtime/freebsd/amd64/sys.s
index 1b6246810513717488f45d452d962621bd079b8f..30184e297c1639a0c5a2aa758b1c5389a8fa59fa 100644 (file)
--- a/src/pkg/runtime/freebsd/amd64/sys.s
+++ b/src/pkg/runtime/freebsd/amd64/sys.s
@@ -28,6 +28,7 @@ TEXT thr_new(SB),7,$0
 TEXT thr_start(SB),7,$0
        MOVQ DI, m
        MOVQ m_g0(m), g
+       CALL stackcheck(SB)
        CALL mstart(SB)
        MOVQ 0, AX                      // crash (not reached)
 

diff --git a/src/pkg/runtime/freebsd/thread.c b/src/pkg/runtime/freebsd/thread.c
index 5f440223651d0eb3b90d9d68432845917e6916b4..bf891e9804640babd289dbc57ea8e87d013f7d44 100644 (file)
--- a/src/pkg/runtime/freebsd/thread.c
+++ b/src/pkg/runtime/freebsd/thread.c
@@ -139,8 +139,8 @@ newosproc(M *m, G *g, void *stk, void (*fn)(void))
 
        param.start_func = thr_start;
        param.arg = m;
-       param.stack_base = stk;
-       param.stack_size = g->stackbase - g->stackguard + 256;
+       param.stack_base = (int8*)g->stackbase;
+       param.stack_size = (byte*)stk - (byte*)g->stackbase;
        param.child_tid = (intptr*)&m->procid;
        param.parent_tid = nil;
        param.tls_base = (int8*)&m->tls[0];

diff --git a/src/pkg/runtime/linux/386/sys.s b/src/pkg/runtime/linux/386/sys.s
index 097dfe91559bb180cde4bc292c5498b162b27bef..72882cb9dccbdd3cf6ec4100bfc4db3ae150d1cc 100644 (file)
--- a/src/pkg/runtime/linux/386/sys.s
+++ b/src/pkg/runtime/linux/386/sys.s
@@ -152,6 +152,7 @@ TEXT clone(SB),7,$0
        MOVL    DX, g
        MOVL    BX, m
 
+       CALL    stackcheck(SB)  // smashes AX
        MOVL    0(DX), DX       // paranoia; check they are not nil
        MOVL    0(BX), BX
 

diff --git a/src/pkg/runtime/linux/amd64/sys.s b/src/pkg/runtime/linux/amd64/sys.s
index 238a423b13a25854cb506406d8b7ebe3d0386f30..6565d86de2a25d48ab48cf8f71bbf4fc9f0f7b50 100644 (file)
--- a/src/pkg/runtime/linux/amd64/sys.s
+++ b/src/pkg/runtime/linux/amd64/sys.s
@@ -149,6 +149,7 @@ TEXT clone(SB),7,$0
        MOVQ    SI, SP
        MOVQ    R8, m
        MOVQ    R9, g
+       CALL    stackcheck(SB)
 
        // Initialize m->procid to Linux tid
        MOVL    $186, AX        // gettid