fix arm bug in reflect.call

R=rsc
CC=golang-dev
https://golang.org/cl/2475042

src/cmd/5l/asm.c

@@ -2087,12 +2087,13 @@ olr(int32 v, int b, int r, int sc)
 		o |= 1 << 23;
 	if(sc & C_WBIT)
 		o |= 1 << 21;
-	o |= (0x1<<26) | (1<<20);
+	o |= (1<<26) | (1<<20);
 	if(v < 0) {
+		if(sc & C_UBIT) diag(".U on neg offset");
 		v = -v;
 		o ^= 1 << 23;
 	}
-	if(v >= (1<<12))
+	if(v >= (1<<12) || v < 0)
 		diag("literal span too large: %d (R%d)\n%P", v, b, PP);
 	o |= v;
 	o |= b << 16;
@@ -2117,7 +2118,7 @@ olhr(int32 v, int b, int r, int sc)
 		v = -v;
 		o ^= 1 << 23;
 	}
-	if(v >= (1<<8))
+	if(v >= (1<<8) || v < 0)
 		diag("literal span too large: %d (R%d)\n%P", v, b, PP);
 	o |= (v&0xf)|((v>>4)<<8)|(1<<22);
 	o |= b << 16;
@@ -2191,7 +2192,8 @@ ofsr(int a, int r, int32 v, int b, int sc, Prog *p)
 	}
 	if(v & 3)
 		diag("odd offset for floating point op: %d\n%P", v, p);
-	else if(v >= (1<<10))
+	else
+	if(v >= (1<<10) || v < 0)
 		diag("literal span too large: %d\n%P", v, p);
 	o |= (v>>2) & 0xFF;
 	o |= b << 16;

src/pkg/runtime/arm/asm.s

@@ -123,7 +123,6 @@ TEXT gogocall(SB), 7, $-4
 	MOVW	0(g), R3		// make sure g != nil
 	MOVW	gobuf_sp(R0), SP	// restore SP
 	MOVW	gobuf_pc(R0), LR
-	SUB	R2, SP
 	MOVW	R1, PC
 
 /*
@@ -141,8 +140,7 @@ TEXT ·morestack(SB),7,$-4
 	// Cannot grow scheduler stack (m->g0).
 	MOVW	m_g0(m), R4
 	CMP	g, R4
-	BNE	2(PC)
-	BL	abort(SB)
+	BL.EQ	abort(SB)
 
 	// Save in m.
 	MOVW	R1, m_moreframe(m)
@@ -185,6 +183,9 @@ TEXT reflect·call(SB), 7, $-4
 	MOVW	8(SP), R1			// arg frame
 	MOVW	12(SP), R2			// arg size
 
+	SUB	$4,R1				// add the saved LR to the frame
+	ADD	$4,R2
+
 	MOVW	R0, m_morepc(m)			// f's PC
 	MOVW	R1, m_morefp(m)			// argument frame pointer
 	MOVW	R2, m_moreargs(m)		// f's argument size

src/pkg/runtime/proc.c

@@ -527,8 +527,9 @@ scheduler(void)
 	gp->status = Grunning;
 	m->curg = gp;
 	gp->m = m;
-	if(gp->sched.pc == (byte*)goexit)	// kickoff
-		gogocall(&gp->sched, (void(*)(void))gp->entry, 0);
+	if(gp->sched.pc == (byte*)goexit) {	// kickoff
+		gogocall(&gp->sched, (void(*)(void))gp->entry);
+	}
 	gogo(&gp->sched, 1);
 }
 
@@ -770,7 +771,8 @@ newstack(void)
 		free = true;
 	}
 
-//printf("newstack frame=%d args=%d morepc=%p morefp=%p gobuf=%p, %p newstk=%p\n", frame, args, m->morepc, m->morefp, g->sched.pc, g->sched.sp, stk);
+//printf("newstack frame=%d args=%d morepc=%p morefp=%p gobuf=%p, %p newstk=%p\n",
+//frame, args, m->morepc, m->morefp, g->sched.pc, g->sched.sp, stk);
 
 	top->stackbase = g1->stackbase;
 	top->stackguard = g1->stackguard;
@@ -797,7 +799,7 @@ newstack(void)
 	label.sp = sp;
 	label.pc = (byte*)·lessstack;
 	label.g = m->curg;
-	gogocall(&label, m->morepc, 0);
+	gogocall(&label, m->morepc);
 
 	*(int32*)345 = 123;	// never return
 }

src/pkg/runtime/runtime.h

@@ -377,7 +377,7 @@ int32	charntorune(int32*, uint8*, int32);
  * very low level c-called
  */
 void	gogo(Gobuf*, uintptr);
-void	gogocall(Gobuf*, void(*)(void), int64);
+void	gogocall(Gobuf*, void(*)(void));
 uintptr	gosave(Gobuf*);
 void	·lessstack(void);
 void	goargs(void);