runtime: make framepointer mode safe for Windows

A few other architectures have already defined a NOFRAME flag.
Use it to disable frame pointer code on a few very low-level functions
that must behave like Windows code.

Makes the failing os/signal test pass on a Windows gomote.

Change-Id: I982365f2c59a0aa302b4428c970846c61027cf3e
Reviewed-on: https://go-review.googlesource.com/23456
Reviewed-by: Austin Clements <austin@google.com>

diff --git a/src/cmd/internal/obj/x86/obj6.go b/src/cmd/internal/obj/x86/obj6.go
index df774437ac51dc9331b4bcb91253db833e374c27..0f1f28d36d6d940d0e984380c1c32d9b931f3d64 100644 (file)
--- a/src/cmd/internal/obj/x86/obj6.go
+++ b/src/cmd/internal/obj/x86/obj6.go
@@ -610,12 +610,11 @@ func preprocess(ctxt *obj.Link, cursym *obj.LSym) {
        }
 
        var bpsize int
-       if p.Mode == 64 && obj.Framepointer_enabled != 0 && autoffset > 0 {
+       if p.Mode == 64 && obj.Framepointer_enabled != 0 && autoffset > 0 && p.From3.Offset&obj.NOFRAME == 0 {
                // Make room for to save a base pointer. If autoffset == 0,
                // this might do something special like a tail jump to
                // another function, so in that case we omit this.
                bpsize = ctxt.Arch.PtrSize
-
                autoffset += int32(bpsize)
                p.To.Offset += int64(bpsize)
        } else {

diff --git a/src/runtime/sys_windows_amd64.s b/src/runtime/sys_windows_amd64.s
index d550a818ce85f1632375f808706bf5d0bf4560f9..9c197379fb8f421e11523ef7e49bc3cbcee7c6bf 100644 (file)
--- a/src/runtime/sys_windows_amd64.s
+++ b/src/runtime/sys_windows_amd64.s
@@ -11,7 +11,7 @@
 #define maxargs 16
 
 // void runtime·asmstdcall(void *c);
-TEXT runtime·asmstdcall(SB),NOSPLIT,$0
+TEXT runtime·asmstdcall(SB),NOSPLIT|NOFRAME,$0
        // asmcgocall will put first argument into CX.
        PUSHQ   CX                      // save for later
        MOVQ    libcall_fn(CX), AX
@@ -62,7 +62,7 @@ loadregs:
 
        RET
 
-TEXT runtime·badsignal2(SB),NOSPLIT,$48
+TEXT runtime·badsignal2(SB),NOSPLIT|NOFRAME,$48
        // stderr
        MOVQ    $-12, CX // stderr
        MOVQ    CX, 0(SP)
@@ -102,7 +102,7 @@ TEXT runtime·setlasterror(SB),NOSPLIT,$0
 // exception record and context pointers.
 // Handler function is stored in AX.
 // Return 0 for 'not handled', -1 for handled.
-TEXT runtime·sigtramp(SB),NOSPLIT,$0-0
+TEXT runtime·sigtramp(SB),NOSPLIT|NOFRAME,$0-0
        // CX: PEXCEPTION_POINTERS ExceptionInfo
 
        // DI SI BP BX R12 R13 R14 R15 registers and DF flag are preserved
@@ -190,32 +190,32 @@ done:
 
        RET
 
-TEXT runtime·exceptiontramp(SB),NOSPLIT,$0
+TEXT runtime·exceptiontramp(SB),NOSPLIT|NOFRAME,$0
        MOVQ    $runtime·exceptionhandler(SB), AX
        JMP     runtime·sigtramp(SB)
 
-TEXT runtime·firstcontinuetramp(SB),NOSPLIT,$0-0
+TEXT runtime·firstcontinuetramp(SB),NOSPLIT|NOFRAME,$0-0
        MOVQ    $runtime·firstcontinuehandler(SB), AX
        JMP     runtime·sigtramp(SB)
 
-TEXT runtime·lastcontinuetramp(SB),NOSPLIT,$0-0
+TEXT runtime·lastcontinuetramp(SB),NOSPLIT|NOFRAME,$0-0
        MOVQ    $runtime·lastcontinuehandler(SB), AX
        JMP     runtime·sigtramp(SB)
 
-TEXT runtime·ctrlhandler(SB),NOSPLIT,$8
+TEXT runtime·ctrlhandler(SB),NOSPLIT|NOFRAME,$8
        MOVQ    CX, 16(SP)              // spill
        MOVQ    $runtime·ctrlhandler1(SB), CX
        MOVQ    CX, 0(SP)
        CALL    runtime·externalthreadhandler(SB)
        RET
 
-TEXT runtime·profileloop(SB),NOSPLIT,$8
+TEXT runtime·profileloop(SB),NOSPLIT|NOFRAME,$8
        MOVQ    $runtime·profileloop1(SB), CX
        MOVQ    CX, 0(SP)
        CALL    runtime·externalthreadhandler(SB)
        RET
 
-TEXT runtime·externalthreadhandler(SB),NOSPLIT,$0
+TEXT runtime·externalthreadhandler(SB),NOSPLIT|NOFRAME,$0
        PUSHQ   BP
        MOVQ    SP, BP
        PUSHQ   BX
@@ -228,7 +228,7 @@ TEXT runtime·externalthreadhandler(SB),NOSPLIT,$0
        SUBQ    $m__size, SP            // space for M
        MOVQ    SP, 0(SP)
        MOVQ    $m__size, 8(SP)
-       CALL    runtime·memclr(SB)     // smashes AX,BX,CX
+       CALL    runtime·memclr(SB)     // smashes AX,BX,CX, maybe BP
 
        LEAQ    m_tls(SP), CX
        MOVQ    CX, 0x28(GS)
@@ -239,7 +239,7 @@ TEXT runtime·externalthreadhandler(SB),NOSPLIT,$0
 
        MOVQ    SP, 0(SP)
        MOVQ    $g__size, 8(SP)
-       CALL    runtime·memclr(SB)     // smashes AX,BX,CX
+       CALL    runtime·memclr(SB)     // smashes AX,BX,CX, maybe BP
        LEAQ    g__size(SP), BX
        MOVQ    BX, g_m(SP)
 
@@ -430,7 +430,7 @@ ret:
 // Runs on OS stack. duration (in 100ns units) is in BX.
 // The function leaves room for 4 syscall parameters
 // (as per windows amd64 calling convention).
-TEXT runtime·usleep2(SB),NOSPLIT,$48
+TEXT runtime·usleep2(SB),NOSPLIT|NOFRAME,$48
        MOVQ    SP, AX
        ANDQ    $~15, SP        // alignment as per Windows requirement
        MOVQ    AX, 40(SP)
@@ -446,7 +446,7 @@ TEXT runtime·usleep2(SB),NOSPLIT,$48
        RET
 
 // Runs on OS stack.
-TEXT runtime·switchtothread(SB),NOSPLIT,$0
+TEXT runtime·switchtothread(SB),NOSPLIT|NOFRAME,$0
        MOVQ    SP, AX
        ANDQ    $~15, SP        // alignment as per Windows requirement
        SUBQ    $(48), SP       // room for SP and 4 args as per Windows requirement