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eacbfce1 SS |
1 | // SPDX-License-Identifier: GPL-2.0 |
2 | /* | |
3 | * PA-RISC KGDB support | |
4 | * | |
5 | * Copyright (c) 2019 Sven Schnelle <svens@stackframe.org> | |
c1c72d9b | 6 | * Copyright (c) 2022 Helge Deller <deller@gmx.de> |
eacbfce1 SS |
7 | * |
8 | */ | |
9 | ||
10 | #include <linux/kgdb.h> | |
11 | #include <linux/string.h> | |
12 | #include <linux/sched.h> | |
13 | #include <linux/notifier.h> | |
14 | #include <linux/kdebug.h> | |
15 | #include <linux/uaccess.h> | |
16 | #include <asm/ptrace.h> | |
17 | #include <asm/traps.h> | |
18 | #include <asm/processor.h> | |
19 | #include <asm/patch.h> | |
20 | #include <asm/cacheflush.h> | |
21 | ||
22 | const struct kgdb_arch arch_kgdb_ops = { | |
23 | .gdb_bpt_instr = { 0x03, 0xff, 0xa0, 0x1f } | |
24 | }; | |
25 | ||
26 | static int __kgdb_notify(struct die_args *args, unsigned long cmd) | |
27 | { | |
28 | struct pt_regs *regs = args->regs; | |
29 | ||
30 | if (kgdb_handle_exception(1, args->signr, cmd, regs)) | |
31 | return NOTIFY_DONE; | |
32 | return NOTIFY_STOP; | |
33 | } | |
34 | ||
35 | static int kgdb_notify(struct notifier_block *self, | |
36 | unsigned long cmd, void *ptr) | |
37 | { | |
38 | unsigned long flags; | |
39 | int ret; | |
40 | ||
41 | local_irq_save(flags); | |
42 | ret = __kgdb_notify(ptr, cmd); | |
43 | local_irq_restore(flags); | |
44 | ||
45 | return ret; | |
46 | } | |
47 | ||
48 | static struct notifier_block kgdb_notifier = { | |
49 | .notifier_call = kgdb_notify, | |
50 | .priority = -INT_MAX, | |
51 | }; | |
52 | ||
53 | int kgdb_arch_init(void) | |
54 | { | |
55 | return register_die_notifier(&kgdb_notifier); | |
56 | } | |
57 | ||
58 | void kgdb_arch_exit(void) | |
59 | { | |
60 | unregister_die_notifier(&kgdb_notifier); | |
61 | } | |
62 | ||
63 | void pt_regs_to_gdb_regs(unsigned long *gdb_regs, struct pt_regs *regs) | |
64 | { | |
65 | struct parisc_gdb_regs *gr = (struct parisc_gdb_regs *)gdb_regs; | |
66 | ||
67 | memset(gr, 0, sizeof(struct parisc_gdb_regs)); | |
68 | ||
69 | memcpy(gr->gpr, regs->gr, sizeof(gr->gpr)); | |
70 | memcpy(gr->fr, regs->fr, sizeof(gr->fr)); | |
71 | ||
72 | gr->sr0 = regs->sr[0]; | |
73 | gr->sr1 = regs->sr[1]; | |
74 | gr->sr2 = regs->sr[2]; | |
75 | gr->sr3 = regs->sr[3]; | |
76 | gr->sr4 = regs->sr[4]; | |
77 | gr->sr5 = regs->sr[5]; | |
78 | gr->sr6 = regs->sr[6]; | |
79 | gr->sr7 = regs->sr[7]; | |
80 | ||
81 | gr->sar = regs->sar; | |
82 | gr->iir = regs->iir; | |
83 | gr->isr = regs->isr; | |
84 | gr->ior = regs->ior; | |
85 | gr->ipsw = regs->ipsw; | |
86 | gr->cr27 = regs->cr27; | |
87 | ||
88 | gr->iaoq_f = regs->iaoq[0]; | |
89 | gr->iasq_f = regs->iasq[0]; | |
90 | ||
91 | gr->iaoq_b = regs->iaoq[1]; | |
92 | gr->iasq_b = regs->iasq[1]; | |
93 | } | |
94 | ||
95 | void gdb_regs_to_pt_regs(unsigned long *gdb_regs, struct pt_regs *regs) | |
96 | { | |
97 | struct parisc_gdb_regs *gr = (struct parisc_gdb_regs *)gdb_regs; | |
98 | ||
99 | ||
100 | memcpy(regs->gr, gr->gpr, sizeof(regs->gr)); | |
101 | memcpy(regs->fr, gr->fr, sizeof(regs->fr)); | |
102 | ||
103 | regs->sr[0] = gr->sr0; | |
104 | regs->sr[1] = gr->sr1; | |
105 | regs->sr[2] = gr->sr2; | |
106 | regs->sr[3] = gr->sr3; | |
107 | regs->sr[4] = gr->sr4; | |
108 | regs->sr[5] = gr->sr5; | |
109 | regs->sr[6] = gr->sr6; | |
110 | regs->sr[7] = gr->sr7; | |
111 | ||
112 | regs->sar = gr->sar; | |
113 | regs->iir = gr->iir; | |
114 | regs->isr = gr->isr; | |
115 | regs->ior = gr->ior; | |
116 | regs->ipsw = gr->ipsw; | |
117 | regs->cr27 = gr->cr27; | |
118 | ||
119 | regs->iaoq[0] = gr->iaoq_f; | |
120 | regs->iasq[0] = gr->iasq_f; | |
121 | ||
122 | regs->iaoq[1] = gr->iaoq_b; | |
123 | regs->iasq[1] = gr->iasq_b; | |
124 | } | |
125 | ||
126 | void sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, | |
127 | struct task_struct *task) | |
128 | { | |
129 | struct pt_regs *regs = task_pt_regs(task); | |
130 | unsigned long gr30, iaoq; | |
131 | ||
132 | gr30 = regs->gr[30]; | |
133 | iaoq = regs->iaoq[0]; | |
134 | ||
135 | regs->gr[30] = regs->ksp; | |
136 | regs->iaoq[0] = regs->kpc; | |
137 | pt_regs_to_gdb_regs(gdb_regs, regs); | |
138 | ||
139 | regs->gr[30] = gr30; | |
140 | regs->iaoq[0] = iaoq; | |
141 | ||
142 | } | |
143 | ||
144 | static void step_instruction_queue(struct pt_regs *regs) | |
145 | { | |
146 | regs->iaoq[0] = regs->iaoq[1]; | |
147 | regs->iaoq[1] += 4; | |
148 | } | |
149 | ||
150 | void kgdb_arch_set_pc(struct pt_regs *regs, unsigned long ip) | |
151 | { | |
152 | regs->iaoq[0] = ip; | |
153 | regs->iaoq[1] = ip + 4; | |
154 | } | |
155 | ||
156 | int kgdb_arch_set_breakpoint(struct kgdb_bkpt *bpt) | |
157 | { | |
fe557319 CH |
158 | int ret = copy_from_kernel_nofault(bpt->saved_instr, |
159 | (char *)bpt->bpt_addr, BREAK_INSTR_SIZE); | |
eacbfce1 SS |
160 | if (ret) |
161 | return ret; | |
162 | ||
163 | __patch_text((void *)bpt->bpt_addr, | |
164 | *(unsigned int *)&arch_kgdb_ops.gdb_bpt_instr); | |
165 | return ret; | |
166 | } | |
167 | ||
168 | int kgdb_arch_remove_breakpoint(struct kgdb_bkpt *bpt) | |
169 | { | |
170 | __patch_text((void *)bpt->bpt_addr, *(unsigned int *)&bpt->saved_instr); | |
171 | return 0; | |
172 | } | |
173 | ||
174 | int kgdb_arch_handle_exception(int trap, int signo, | |
175 | int err_code, char *inbuf, char *outbuf, | |
176 | struct pt_regs *regs) | |
177 | { | |
178 | unsigned long addr; | |
179 | char *p = inbuf + 1; | |
180 | ||
181 | switch (inbuf[0]) { | |
182 | case 'D': | |
183 | case 'c': | |
184 | case 'k': | |
185 | kgdb_contthread = NULL; | |
186 | kgdb_single_step = 0; | |
187 | ||
188 | if (kgdb_hex2long(&p, &addr)) | |
189 | kgdb_arch_set_pc(regs, addr); | |
190 | else if (trap == 9 && regs->iir == | |
191 | PARISC_KGDB_COMPILED_BREAK_INSN) | |
192 | step_instruction_queue(regs); | |
193 | return 0; | |
194 | case 's': | |
195 | kgdb_single_step = 1; | |
196 | if (kgdb_hex2long(&p, &addr)) { | |
197 | kgdb_arch_set_pc(regs, addr); | |
198 | } else if (trap == 9 && regs->iir == | |
199 | PARISC_KGDB_COMPILED_BREAK_INSN) { | |
200 | step_instruction_queue(regs); | |
201 | mtctl(-1, 0); | |
202 | } else { | |
203 | mtctl(0, 0); | |
204 | } | |
205 | regs->gr[0] |= PSW_R; | |
206 | return 0; | |
207 | ||
208 | } | |
209 | return -1; | |
210 | } |