1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | /* |
3 | * arch/hexagon/kernel/kgdb.c - Hexagon KGDB Support |
4 | * |
5 | * Copyright (c) 2011-2012, The Linux Foundation. All rights reserved. |
6 | */ |
7 | |
8 | #include <linux/irq.h> |
9 | #include <linux/sched.h> |
10 | #include <linux/sched/task_stack.h> |
11 | #include <linux/kdebug.h> |
12 | #include <linux/kgdb.h> |
13 | |
14 | /* All registers are 4 bytes, for now */ |
15 | #define GDB_SIZEOF_REG 4 |
16 | |
17 | /* The register names are used during printing of the regs; |
18 | * Keep these at three letters to pretty-print. */ |
19 | struct dbg_reg_def_t dbg_reg_def[DBG_MAX_REG_NUM] = { |
20 | { " r0" , GDB_SIZEOF_REG, offsetof(struct pt_regs, r00)}, |
21 | { " r1" , GDB_SIZEOF_REG, offsetof(struct pt_regs, r01)}, |
22 | { " r2" , GDB_SIZEOF_REG, offsetof(struct pt_regs, r02)}, |
23 | { " r3" , GDB_SIZEOF_REG, offsetof(struct pt_regs, r03)}, |
24 | { " r4" , GDB_SIZEOF_REG, offsetof(struct pt_regs, r04)}, |
25 | { " r5" , GDB_SIZEOF_REG, offsetof(struct pt_regs, r05)}, |
26 | { " r6" , GDB_SIZEOF_REG, offsetof(struct pt_regs, r06)}, |
27 | { " r7" , GDB_SIZEOF_REG, offsetof(struct pt_regs, r07)}, |
28 | { " r8" , GDB_SIZEOF_REG, offsetof(struct pt_regs, r08)}, |
29 | { " r9" , GDB_SIZEOF_REG, offsetof(struct pt_regs, r09)}, |
30 | { "r10" , GDB_SIZEOF_REG, offsetof(struct pt_regs, r10)}, |
31 | { "r11" , GDB_SIZEOF_REG, offsetof(struct pt_regs, r11)}, |
32 | { "r12" , GDB_SIZEOF_REG, offsetof(struct pt_regs, r12)}, |
33 | { "r13" , GDB_SIZEOF_REG, offsetof(struct pt_regs, r13)}, |
34 | { "r14" , GDB_SIZEOF_REG, offsetof(struct pt_regs, r14)}, |
35 | { "r15" , GDB_SIZEOF_REG, offsetof(struct pt_regs, r15)}, |
36 | { "r16" , GDB_SIZEOF_REG, offsetof(struct pt_regs, r16)}, |
37 | { "r17" , GDB_SIZEOF_REG, offsetof(struct pt_regs, r17)}, |
38 | { "r18" , GDB_SIZEOF_REG, offsetof(struct pt_regs, r18)}, |
39 | { "r19" , GDB_SIZEOF_REG, offsetof(struct pt_regs, r19)}, |
40 | { "r20" , GDB_SIZEOF_REG, offsetof(struct pt_regs, r20)}, |
41 | { "r21" , GDB_SIZEOF_REG, offsetof(struct pt_regs, r21)}, |
42 | { "r22" , GDB_SIZEOF_REG, offsetof(struct pt_regs, r22)}, |
43 | { "r23" , GDB_SIZEOF_REG, offsetof(struct pt_regs, r23)}, |
44 | { "r24" , GDB_SIZEOF_REG, offsetof(struct pt_regs, r24)}, |
45 | { "r25" , GDB_SIZEOF_REG, offsetof(struct pt_regs, r25)}, |
46 | { "r26" , GDB_SIZEOF_REG, offsetof(struct pt_regs, r26)}, |
47 | { "r27" , GDB_SIZEOF_REG, offsetof(struct pt_regs, r27)}, |
48 | { "r28" , GDB_SIZEOF_REG, offsetof(struct pt_regs, r28)}, |
49 | { "r29" , GDB_SIZEOF_REG, offsetof(struct pt_regs, r29)}, |
50 | { "r30" , GDB_SIZEOF_REG, offsetof(struct pt_regs, r30)}, |
51 | { "r31" , GDB_SIZEOF_REG, offsetof(struct pt_regs, r31)}, |
52 | |
53 | { "usr" , GDB_SIZEOF_REG, offsetof(struct pt_regs, usr)}, |
54 | { "preds" , GDB_SIZEOF_REG, offsetof(struct pt_regs, preds)}, |
55 | { " m0" , GDB_SIZEOF_REG, offsetof(struct pt_regs, m0)}, |
56 | { " m1" , GDB_SIZEOF_REG, offsetof(struct pt_regs, m1)}, |
57 | { "sa0" , GDB_SIZEOF_REG, offsetof(struct pt_regs, sa0)}, |
58 | { "sa1" , GDB_SIZEOF_REG, offsetof(struct pt_regs, sa1)}, |
59 | { "lc0" , GDB_SIZEOF_REG, offsetof(struct pt_regs, lc0)}, |
60 | { "lc1" , GDB_SIZEOF_REG, offsetof(struct pt_regs, lc1)}, |
61 | { " gp" , GDB_SIZEOF_REG, offsetof(struct pt_regs, gp)}, |
62 | { "ugp" , GDB_SIZEOF_REG, offsetof(struct pt_regs, ugp)}, |
63 | { "cs0" , GDB_SIZEOF_REG, offsetof(struct pt_regs, cs0)}, |
64 | { "cs1" , GDB_SIZEOF_REG, offsetof(struct pt_regs, cs1)}, |
65 | { "psp" , GDB_SIZEOF_REG, offsetof(struct pt_regs, hvmer.vmpsp)}, |
66 | { "elr" , GDB_SIZEOF_REG, offsetof(struct pt_regs, hvmer.vmel)}, |
67 | { "est" , GDB_SIZEOF_REG, offsetof(struct pt_regs, hvmer.vmest)}, |
68 | { "badva" , GDB_SIZEOF_REG, offsetof(struct pt_regs, hvmer.vmbadva)}, |
69 | { "restart_r0" , GDB_SIZEOF_REG, offsetof(struct pt_regs, restart_r0)}, |
70 | { "syscall_nr" , GDB_SIZEOF_REG, offsetof(struct pt_regs, syscall_nr)}, |
71 | }; |
72 | |
73 | const struct kgdb_arch arch_kgdb_ops = { |
74 | /* trap0(#0xDB) 0x0cdb0054 */ |
75 | .gdb_bpt_instr = {0x54, 0x00, 0xdb, 0x0c}, |
76 | }; |
77 | |
78 | char *dbg_get_reg(int regno, void *mem, struct pt_regs *regs) |
79 | { |
80 | if (regno >= DBG_MAX_REG_NUM || regno < 0) |
81 | return NULL; |
82 | |
83 | *((unsigned long *) mem) = *((unsigned long *) ((void *)regs + |
84 | dbg_reg_def[regno].offset)); |
85 | |
86 | return dbg_reg_def[regno].name; |
87 | } |
88 | |
89 | int dbg_set_reg(int regno, void *mem, struct pt_regs *regs) |
90 | { |
91 | if (regno >= DBG_MAX_REG_NUM || regno < 0) |
92 | return -EINVAL; |
93 | |
94 | *((unsigned long *) ((void *)regs + dbg_reg_def[regno].offset)) = |
95 | *((unsigned long *) mem); |
96 | |
97 | return 0; |
98 | } |
99 | |
100 | void kgdb_arch_set_pc(struct pt_regs *regs, unsigned long pc) |
101 | { |
102 | instruction_pointer(regs) = pc; |
103 | } |
104 | |
105 | |
106 | /* Not yet working */ |
107 | void sleeping_thread_to_gdb_regs(unsigned long *gdb_regs, |
108 | struct task_struct *task) |
109 | { |
110 | struct pt_regs *thread_regs; |
111 | |
112 | if (task == NULL) |
113 | return; |
114 | |
115 | /* Initialize to zero */ |
116 | memset(gdb_regs, 0, NUMREGBYTES); |
117 | |
118 | /* Otherwise, we have only some registers from switch_to() */ |
119 | thread_regs = task_pt_regs(task); |
120 | gdb_regs[0] = thread_regs->r00; |
121 | } |
122 | |
123 | /** |
124 | * kgdb_arch_handle_exception - Handle architecture specific GDB packets. |
125 | * @vector: The error vector of the exception that happened. |
126 | * @signo: The signal number of the exception that happened. |
127 | * @err_code: The error code of the exception that happened. |
128 | * @remcom_in_buffer: The buffer of the packet we have read. |
129 | * @remcom_out_buffer: The buffer of %BUFMAX bytes to write a packet into. |
130 | * @regs: The &struct pt_regs of the current process. |
131 | * |
132 | * This function MUST handle the 'c' and 's' command packets, |
133 | * as well packets to set / remove a hardware breakpoint, if used. |
134 | * If there are additional packets which the hardware needs to handle, |
135 | * they are handled here. The code should return -1 if it wants to |
136 | * process more packets, and a %0 or %1 if it wants to exit from the |
137 | * kgdb callback. |
138 | * |
139 | * Not yet working. |
140 | */ |
141 | int kgdb_arch_handle_exception(int vector, int signo, int err_code, |
142 | char *remcom_in_buffer, char *remcom_out_buffer, |
143 | struct pt_regs *linux_regs) |
144 | { |
145 | switch (remcom_in_buffer[0]) { |
146 | case 's': |
147 | case 'c': |
148 | return 0; |
149 | } |
150 | /* Stay in the debugger. */ |
151 | return -1; |
152 | } |
153 | |
154 | static int __kgdb_notify(struct die_args *args, unsigned long cmd) |
155 | { |
156 | /* cpu roundup */ |
157 | if (atomic_read(v: &kgdb_active) != -1) { |
158 | kgdb_nmicallback(smp_processor_id(), regs: args->regs); |
159 | return NOTIFY_STOP; |
160 | } |
161 | |
162 | if (user_mode(regs: args->regs)) |
163 | return NOTIFY_DONE; |
164 | |
165 | if (kgdb_handle_exception(ex_vector: args->trapnr & 0xff, signo: args->signr, err_code: args->err, |
166 | regs: args->regs)) |
167 | return NOTIFY_DONE; |
168 | |
169 | return NOTIFY_STOP; |
170 | } |
171 | |
172 | static int |
173 | kgdb_notify(struct notifier_block *self, unsigned long cmd, void *ptr) |
174 | { |
175 | unsigned long flags; |
176 | int ret; |
177 | |
178 | local_irq_save(flags); |
179 | ret = __kgdb_notify(args: ptr, cmd); |
180 | local_irq_restore(flags); |
181 | |
182 | return ret; |
183 | } |
184 | |
185 | static struct notifier_block kgdb_notifier = { |
186 | .notifier_call = kgdb_notify, |
187 | |
188 | /* |
189 | * Lowest-prio notifier priority, we want to be notified last: |
190 | */ |
191 | .priority = -INT_MAX, |
192 | }; |
193 | |
194 | /** |
195 | * kgdb_arch_init - Perform any architecture specific initialization. |
196 | * |
197 | * This function will handle the initialization of any architecture |
198 | * specific callbacks. |
199 | */ |
200 | int kgdb_arch_init(void) |
201 | { |
202 | return register_die_notifier(nb: &kgdb_notifier); |
203 | } |
204 | |
205 | /** |
206 | * kgdb_arch_exit - Perform any architecture specific uninitalization. |
207 | * |
208 | * This function will handle the uninitalization of any architecture |
209 | * specific callbacks, for dynamic registration and unregistration. |
210 | */ |
211 | void kgdb_arch_exit(void) |
212 | { |
213 | unregister_die_notifier(nb: &kgdb_notifier); |
214 | } |
215 | |