code review 109050043: all: remove 'extern register M *m' from runtime

src/pkg/runtime/signal_386.c

 // Copyright 2013 The Go Authors.  All rights reserved.
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
 // +build darwin dragonfly freebsd linux nacl netbsd openbsd
 
 #include "runtime.h"
 #include "defs_GOOS_GOARCH.h"
 #include "os_GOOS.h"
 #include "signal_GOOS_GOARCH.h"
@@ skipping 21 matching lines @@
 }
 
 void
 runtime·sighandler(int32 sig, Siginfo *info, void *ctxt, G *gp)
 {
         uintptr *sp;
         SigTab *t;
         bool crash;
 
         if(sig == SIGPROF) {
-                runtime·sigprof((byte*)SIG_EIP(info, ctxt), (byte*)SIG_ESP(info, ctxt), nil, gp, m);
+                runtime·sigprof((byte*)SIG_EIP(info, ctxt), (byte*)SIG_ESP(info, ctxt), nil, gp, g->m);
                 return;
         }
 
         t = &runtime·sigtab[sig];
         if(SIG_CODE0(info, ctxt) != SI_USER && (t->flags & SigPanic)) {
                 // Make it look like a call to the signal func.
                 // Have to pass arguments out of band since
                 // augmenting the stack frame would break
                 // the unwinding code.
                 gp->sig = sig;
@@ skipping 31 matching lines @@
         }
 
         if(SIG_CODE0(info, ctxt) == SI_USER || (t->flags & SigNotify))
                 if(runtime·sigsend(sig))
                         return;
         if(t->flags & SigKill)
                 runtime·exit(2);
         if(!(t->flags & SigThrow))
                 return;
 
-        m->throwing = 1;
-        m->caughtsig = gp;
+        g->m->throwing = 1;
+        g->m->caughtsig = gp;
         runtime·startpanic();
 
         if(sig < 0 || sig >= NSIG)
                 runtime·printf("Signal %d\n", sig);
         else
                 runtime·printf("%s\n", runtime·sigtab[sig].name);
 
         runtime·printf("PC=%x\n", SIG_EIP(info, ctxt));
-        if(m->lockedg != nil && m->ncgo > 0 && gp == m->g0) {
+        if(g->m->lockedg != nil && g->m->ncgo > 0 && gp == g->m->g0) {
                 runtime·printf("signal arrived during cgo execution\n");
-                gp = m->lockedg;
-        }       
+                gp = g->m->lockedg;
+        }
         runtime·printf("\n");
 
         if(runtime·gotraceback(&crash)){
                 runtime·goroutineheader(gp);
                 runtime·traceback(SIG_EIP(info, ctxt), SIG_ESP(info, ctxt), 0, gp);
                 runtime·tracebackothers(gp);
                 runtime·printf("\n");
                 runtime·dumpregs(info, ctxt);
         }
 ········
         if(crash)
                 runtime·crash();
 
         runtime·exit(2);
 }