1// Copyright 2022 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//go:build linux && loong64
6
7package runtime
8
9import (
10	"internal/abi"
11	"internal/goarch"
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}
51
52//go:nosplit
53//go:nowritebarrierrec
54func (c *sigctxt) sigpc() uintptr { return uintptr(c.pc()) }
55
56func (c *sigctxt) sigsp() uintptr { return uintptr(c.sp()) }
57func (c *sigctxt) siglr() uintptr { return uintptr(c.link()) }
58func (c *sigctxt) fault() uintptr { return uintptr(c.sigaddr()) }
59
60// preparePanic sets up the stack to look like a call to sigpanic.
61func (c *sigctxt) preparePanic(sig uint32, gp *g) {
62	// We arrange link, and pc to pretend the panicking
63	// function calls sigpanic directly.
64	// Always save LINK to stack so that panics in leaf
65	// functions are correctly handled. This smashes
66	// the stack frame but we're not going back there
67	// anyway.
68	sp := c.sp() - goarch.PtrSize
69	c.set_sp(sp)
70	*(*uint64)(unsafe.Pointer(uintptr(sp))) = c.link()
71
72	pc := gp.sigpc
73
74	if shouldPushSigpanic(gp, pc, uintptr(c.link())) {
75		// Make it look the like faulting PC called sigpanic.
76		c.set_link(uint64(pc))
77	}
78
79	// In case we are panicking from external C code
80	c.set_r22(uint64(uintptr(unsafe.Pointer(gp))))
81	c.set_pc(uint64(abi.FuncPCABIInternal(sigpanic)))
82}
83
84func (c *sigctxt) pushCall(targetPC, resumePC uintptr) {
85	// Push the LR to stack, as we'll clobber it in order to
86	// push the call. The function being pushed is responsible
87	// for restoring the LR and setting the SP back.
88	// This extra slot is known to gentraceback.
89	sp := c.sp() - 8
90	c.set_sp(sp)
91	*(*uint64)(unsafe.Pointer(uintptr(sp))) = c.link()
92	// Set up PC and LR to pretend the function being signaled
93	// calls targetPC at resumePC.
94	c.set_link(uint64(resumePC))
95	c.set_pc(uint64(targetPC))
96}
97