runtime: fix racefuncenter argument corruption.

Revision 6a88e1893941 corrupts the argument to
racefuncenter by pushing the data block pointer
to the stack.

Fixes #4885.

R=dvyukov, rsc
CC=golang-dev
https://golang.org/cl/7381053

diff --git a/src/pkg/runtime/race.c b/src/pkg/runtime/race.c
index 17573a6978b887b324038b5bfd00be603cb47a9a..cfd97041a8002f8bd50fd60f3647df605c614421 100644 (file)
--- a/src/pkg/runtime/race.c
+++ b/src/pkg/runtime/race.c
@@ -94,10 +94,7 @@ runtime·racefuncenter1(uintptr pc)
 {
        // If the caller PC is lessstack, use slower runtime·callers
        // to walk across the stack split to find the real caller.
-       // Same thing if the PC is on the heap, which should be a
-       // closure trampoline.
-       if(pc == (uintptr)runtime·lessstack ||
-               (pc >= (uintptr)runtime·mheap->arena_start && pc < (uintptr)runtime·mheap->arena_used))
+       if(pc == (uintptr)runtime·lessstack)
                runtime·callers(2, &pc, 1);
 
        m->racecall = true;
@@ -162,8 +159,7 @@ memoryaccess(void *addr, uintptr callpc, uintptr pc, bool write)
                m->racecall = true;
                racectx = g->racectx;
                if(callpc) {
-                       if(callpc == (uintptr)runtime·lessstack ||
-                               (callpc >= (uintptr)runtime·mheap->arena_start && callpc < (uintptr)runtime·mheap->arena_used))
+                       if(callpc == (uintptr)runtime·lessstack)
                                runtime·callers(3, &callpc, 1);
                        runtime∕race·FuncEnter(racectx, (void*)callpc);
                }
@@ -198,8 +194,7 @@ rangeaccess(void *addr, uintptr size, uintptr step, uintptr callpc, uintptr pc,
                m->racecall = true;
                racectx = g->racectx;
                if(callpc) {
-                       if(callpc == (uintptr)runtime·lessstack ||
-                               (callpc >= (uintptr)runtime·mheap->arena_start && callpc < (uintptr)runtime·mheap->arena_used))
+                       if(callpc == (uintptr)runtime·lessstack)
                                runtime·callers(3, &callpc, 1);
                        runtime∕race·FuncEnter(racectx, (void*)callpc);
                }

diff --git a/src/pkg/runtime/race_amd64.s b/src/pkg/runtime/race_amd64.s
index 0c6aaaa611203d69e0f298e0495dd89cd9254790..83e300905e164ddff63fce247f3b0f504c41808d 100644 (file)
--- a/src/pkg/runtime/race_amd64.s
+++ b/src/pkg/runtime/race_amd64.s
@@ -4,8 +4,11 @@
 
 // +build race
 
-TEXT   runtime·racefuncenter(SB),7,$0
-       PUSHQ   DX // save function entry context (for closures)
+// func runtime·racefuncenter(pc uintptr)
+TEXT   runtime·racefuncenter(SB), 7, $16
+       MOVQ    DX, saved-8(SP) // save function entry context (for closures)
+       MOVQ    pc+0(FP), DX
+       MOVQ    DX, arg-16(SP)
        CALL    runtime·racefuncenter1(SB)
-       POPQ    DX
+       MOVQ    saved-8(SP), DX
        RET