1// Copyright 2016 The Go Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style
3// license that can be found in the LICENSE file.
4
5// +build linux
6// +build mips mipsle
7
8package runtime
9
10import (
11	"runtime/internal/sys"
12	"unsafe"
13)
14
15func dumpregs(c *sigctxt) {
16	print("r0   ", hex(c.r0()), "\t")
17	print("r1   ", hex(c.r1()), "\n")
18	print("r2   ", hex(c.r2()), "\t")
19	print("r3   ", hex(c.r3()), "\n")
20	print("r4   ", hex(c.r4()), "\t")
21	print("r5   ", hex(c.r5()), "\n")
22	print("r6   ", hex(c.r6()), "\t")
23	print("r7   ", hex(c.r7()), "\n")
24	print("r8   ", hex(c.r8()), "\t")
25	print("r9   ", hex(c.r9()), "\n")
26	print("r10  ", hex(c.r10()), "\t")
27	print("r11  ", hex(c.r11()), "\n")
28	print("r12  ", hex(c.r12()), "\t")
29	print("r13  ", hex(c.r13()), "\n")
30	print("r14  ", hex(c.r14()), "\t")
31	print("r15  ", hex(c.r15()), "\n")
32	print("r16  ", hex(c.r16()), "\t")
33	print("r17  ", hex(c.r17()), "\n")
34	print("r18  ", hex(c.r18()), "\t")
35	print("r19  ", hex(c.r19()), "\n")
36	print("r20  ", hex(c.r20()), "\t")
37	print("r21  ", hex(c.r21()), "\n")
38	print("r22  ", hex(c.r22()), "\t")
39	print("r23  ", hex(c.r23()), "\n")
40	print("r24  ", hex(c.r24()), "\t")
41	print("r25  ", hex(c.r25()), "\n")
42	print("r26  ", hex(c.r26()), "\t")
43	print("r27  ", hex(c.r27()), "\n")
44	print("r28  ", hex(c.r28()), "\t")
45	print("r29  ", hex(c.r29()), "\n")
46	print("r30  ", hex(c.r30()), "\t")
47	print("r31  ", hex(c.r31()), "\n")
48	print("pc   ", hex(c.pc()), "\t")
49	print("link ", hex(c.link()), "\n")
50	print("lo   ", hex(c.lo()), "\t")
51	print("hi   ", hex(c.hi()), "\n")
52}
53
54func (c *sigctxt) sigpc() uintptr { return uintptr(c.pc()) }
55func (c *sigctxt) sigsp() uintptr { return uintptr(c.sp()) }
56func (c *sigctxt) siglr() uintptr { return uintptr(c.link()) }
57func (c *sigctxt) fault() uintptr { return uintptr(c.sigaddr()) }
58
59// preparePanic sets up the stack to look like a call to sigpanic.
60func (c *sigctxt) preparePanic(sig uint32, gp *g) {
61	// We arrange link, and pc to pretend the panicking
62	// function calls sigpanic directly.
63	// Always save LINK to stack so that panics in leaf
64	// functions are correctly handled. This smashes
65	// the stack frame but we're not going back there
66	// anyway.
67	sp := c.sp() - sys.MinFrameSize
68	c.set_sp(sp)
69	*(*uint32)(unsafe.Pointer(uintptr(sp))) = c.link()
70
71	pc := gp.sigpc
72
73	if shouldPushSigpanic(gp, pc, uintptr(c.link())) {
74		// Make it look the like faulting PC called sigpanic.
75		c.set_link(uint32(pc))
76	}
77
78	// In case we are panicking from external C code
79	c.set_r30(uint32(uintptr(unsafe.Pointer(gp))))
80	c.set_pc(uint32(funcPC(sigpanic)))
81}
82
83const pushCallSupported = true
84
85func (c *sigctxt) pushCall(targetPC uintptr) {
86	// Push the LR to stack, as we'll clobber it in order to
87	// push the call. The function being pushed is responsible
88	// for restoring the LR and setting the SP back.
89	// This extra slot is known to gentraceback.
90	sp := c.sp() - 4
91	c.set_sp(sp)
92	*(*uint32)(unsafe.Pointer(uintptr(sp))) = c.link()
93	// Set up PC and LR to pretend the function being signaled
94	// calls targetPC at the faulting PC.
95	c.set_link(c.pc())
96	c.set_pc(uint32(targetPC))
97}
98