1 /*
2 * linux/arch/m68k/kernel/ptrace.c
3 *
4 * Copyright (C) 1994 by Hamish Macdonald
5 * Taken from linux/kernel/ptrace.c and modified for M680x0.
6 * linux/kernel/ptrace.c is by Ross Biro 1/23/92, edited by Linus Torvalds
7 *
8 * This file is subject to the terms and conditions of the GNU General
9 * Public License. See the file COPYING in the main directory of
10 * this archive for more details.
11 */
12
13 #include <linux/kernel.h>
14 #include <linux/sched.h>
15 #include <linux/sched/task_stack.h>
16 #include <linux/mm.h>
17 #include <linux/smp.h>
18 #include <linux/errno.h>
19 #include <linux/ptrace.h>
20 #include <linux/user.h>
21 #include <linux/signal.h>
22 #include <linux/regset.h>
23 #include <linux/elf.h>
24
25 #include <linux/uaccess.h>
26 #include <asm/page.h>
27 #include <asm/processor.h>
28
29 /*
30 * does not yet catch signals sent when the child dies.
31 * in exit.c or in signal.c.
32 */
33
34 /* determines which bits in the SR the user has access to. */
35 /* 1 = access 0 = no access */
36 #define SR_MASK 0x001f
37
38 /* sets the trace bits. */
39 #define TRACE_BITS 0xC000
40 #define T1_BIT 0x8000
41 #define T0_BIT 0x4000
42
43 /* Find the stack offset for a register, relative to thread.esp0. */
44 #define PT_REG(reg) ((long)&((struct pt_regs *)0)->reg)
45 #define SW_REG(reg) ((long)&((struct switch_stack *)0)->reg \
46 - sizeof(struct switch_stack))
47 /* Mapping from PT_xxx to the stack offset at which the register is
48 saved. Notice that usp has no stack-slot and needs to be treated
49 specially (see get_reg/put_reg below). */
50 static const int regoff[] = {
51 [0] = PT_REG(d1),
52 [1] = PT_REG(d2),
53 [2] = PT_REG(d3),
54 [3] = PT_REG(d4),
55 [4] = PT_REG(d5),
56 [5] = SW_REG(d6),
57 [6] = SW_REG(d7),
58 [7] = PT_REG(a0),
59 [8] = PT_REG(a1),
60 [9] = PT_REG(a2),
61 [10] = SW_REG(a3),
62 [11] = SW_REG(a4),
63 [12] = SW_REG(a5),
64 [13] = SW_REG(a6),
65 [14] = PT_REG(d0),
66 [15] = -1,
67 [16] = PT_REG(orig_d0),
68 [17] = PT_REG(sr),
69 [18] = PT_REG(pc),
70 };
71
72 /*
73 * Get contents of register REGNO in task TASK.
74 */
get_reg(struct task_struct * task,int regno)75 static inline long get_reg(struct task_struct *task, int regno)
76 {
77 unsigned long *addr;
78
79 if (regno == PT_USP)
80 addr = &task->thread.usp;
81 else if (regno < ARRAY_SIZE(regoff))
82 addr = (unsigned long *)(task->thread.esp0 + regoff[regno]);
83 else
84 return 0;
85 /* Need to take stkadj into account. */
86 if (regno == PT_SR || regno == PT_PC) {
87 long stkadj = *(long *)(task->thread.esp0 + PT_REG(stkadj));
88 addr = (unsigned long *) ((unsigned long)addr + stkadj);
89 /* The sr is actually a 16 bit register. */
90 if (regno == PT_SR)
91 return *(unsigned short *)addr;
92 }
93 return *addr;
94 }
95
96 /*
97 * Write contents of register REGNO in task TASK.
98 */
put_reg(struct task_struct * task,int regno,unsigned long data)99 static inline int put_reg(struct task_struct *task, int regno,
100 unsigned long data)
101 {
102 unsigned long *addr;
103
104 if (regno == PT_USP)
105 addr = &task->thread.usp;
106 else if (regno < ARRAY_SIZE(regoff))
107 addr = (unsigned long *)(task->thread.esp0 + regoff[regno]);
108 else
109 return -1;
110 /* Need to take stkadj into account. */
111 if (regno == PT_SR || regno == PT_PC) {
112 long stkadj = *(long *)(task->thread.esp0 + PT_REG(stkadj));
113 addr = (unsigned long *) ((unsigned long)addr + stkadj);
114 /* The sr is actually a 16 bit register. */
115 if (regno == PT_SR) {
116 *(unsigned short *)addr = data;
117 return 0;
118 }
119 }
120 *addr = data;
121 return 0;
122 }
123
124 /*
125 * Make sure the single step bit is not set.
126 */
singlestep_disable(struct task_struct * child)127 static inline void singlestep_disable(struct task_struct *child)
128 {
129 unsigned long tmp = get_reg(child, PT_SR) & ~TRACE_BITS;
130 put_reg(child, PT_SR, tmp);
131 clear_tsk_thread_flag(child, TIF_DELAYED_TRACE);
132 }
133
134 /*
135 * Called by kernel/ptrace.c when detaching..
136 */
ptrace_disable(struct task_struct * child)137 void ptrace_disable(struct task_struct *child)
138 {
139 singlestep_disable(child);
140 }
141
user_enable_single_step(struct task_struct * child)142 void user_enable_single_step(struct task_struct *child)
143 {
144 unsigned long tmp = get_reg(child, PT_SR) & ~TRACE_BITS;
145 put_reg(child, PT_SR, tmp | T1_BIT);
146 set_tsk_thread_flag(child, TIF_DELAYED_TRACE);
147 }
148
149 #ifdef CONFIG_MMU
user_enable_block_step(struct task_struct * child)150 void user_enable_block_step(struct task_struct *child)
151 {
152 unsigned long tmp = get_reg(child, PT_SR) & ~TRACE_BITS;
153 put_reg(child, PT_SR, tmp | T0_BIT);
154 }
155 #endif
156
user_disable_single_step(struct task_struct * child)157 void user_disable_single_step(struct task_struct *child)
158 {
159 singlestep_disable(child);
160 }
161
arch_ptrace(struct task_struct * child,long request,unsigned long addr,unsigned long data)162 long arch_ptrace(struct task_struct *child, long request,
163 unsigned long addr, unsigned long data)
164 {
165 unsigned long tmp;
166 int i, ret = 0;
167 int regno = addr >> 2; /* temporary hack. */
168 unsigned long __user *datap = (unsigned long __user *) data;
169
170 switch (request) {
171 /* read the word at location addr in the USER area. */
172 case PTRACE_PEEKUSR:
173 if (addr & 3)
174 goto out_eio;
175
176 if (regno >= 0 && regno < 19) {
177 tmp = get_reg(child, regno);
178 } else if (regno >= 21 && regno < 49) {
179 tmp = child->thread.fp[regno - 21];
180 /* Convert internal fpu reg representation
181 * into long double format
182 */
183 if (FPU_IS_EMU && (regno < 45) && !(regno % 3))
184 tmp = ((tmp & 0xffff0000) << 15) |
185 ((tmp & 0x0000ffff) << 16);
186 #ifndef CONFIG_MMU
187 } else if (regno == 49) {
188 tmp = child->mm->start_code;
189 } else if (regno == 50) {
190 tmp = child->mm->start_data;
191 } else if (regno == 51) {
192 tmp = child->mm->end_code;
193 #endif
194 } else
195 goto out_eio;
196 ret = put_user(tmp, datap);
197 break;
198
199 case PTRACE_POKEUSR:
200 /* write the word at location addr in the USER area */
201 if (addr & 3)
202 goto out_eio;
203
204 if (regno == PT_SR) {
205 data &= SR_MASK;
206 data |= get_reg(child, PT_SR) & ~SR_MASK;
207 }
208 if (regno >= 0 && regno < 19) {
209 if (put_reg(child, regno, data))
210 goto out_eio;
211 } else if (regno >= 21 && regno < 48) {
212 /* Convert long double format
213 * into internal fpu reg representation
214 */
215 if (FPU_IS_EMU && (regno < 45) && !(regno % 3)) {
216 data <<= 15;
217 data = (data & 0xffff0000) |
218 ((data & 0x0000ffff) >> 1);
219 }
220 child->thread.fp[regno - 21] = data;
221 } else
222 goto out_eio;
223 break;
224
225 case PTRACE_GETREGS: /* Get all gp regs from the child. */
226 for (i = 0; i < 19; i++) {
227 tmp = get_reg(child, i);
228 ret = put_user(tmp, datap);
229 if (ret)
230 break;
231 datap++;
232 }
233 break;
234
235 case PTRACE_SETREGS: /* Set all gp regs in the child. */
236 for (i = 0; i < 19; i++) {
237 ret = get_user(tmp, datap);
238 if (ret)
239 break;
240 if (i == PT_SR) {
241 tmp &= SR_MASK;
242 tmp |= get_reg(child, PT_SR) & ~SR_MASK;
243 }
244 put_reg(child, i, tmp);
245 datap++;
246 }
247 break;
248
249 case PTRACE_GETFPREGS: /* Get the child FPU state. */
250 if (copy_to_user(datap, &child->thread.fp,
251 sizeof(struct user_m68kfp_struct)))
252 ret = -EFAULT;
253 break;
254
255 case PTRACE_SETFPREGS: /* Set the child FPU state. */
256 if (copy_from_user(&child->thread.fp, datap,
257 sizeof(struct user_m68kfp_struct)))
258 ret = -EFAULT;
259 break;
260
261 case PTRACE_GET_THREAD_AREA:
262 ret = put_user(task_thread_info(child)->tp_value, datap);
263 break;
264
265 default:
266 ret = ptrace_request(child, request, addr, data);
267 break;
268 }
269
270 return ret;
271 out_eio:
272 return -EIO;
273 }
274
syscall_trace_enter(void)275 asmlinkage int syscall_trace_enter(void)
276 {
277 int ret = 0;
278
279 if (test_thread_flag(TIF_SYSCALL_TRACE))
280 ret = ptrace_report_syscall_entry(task_pt_regs(current));
281 return ret;
282 }
283
syscall_trace_leave(void)284 asmlinkage void syscall_trace_leave(void)
285 {
286 if (test_thread_flag(TIF_SYSCALL_TRACE))
287 ptrace_report_syscall_exit(task_pt_regs(current), 0);
288 }
289
290 #if defined(CONFIG_BINFMT_ELF_FDPIC) && defined(CONFIG_ELF_CORE)
291 /*
292 * Currently the only thing that needs to use regsets for m68k is the
293 * coredump support of the elf_fdpic loader. Implement the minimum
294 * definitions required for that.
295 */
m68k_regset_get(struct task_struct * target,const struct user_regset * regset,struct membuf to)296 static int m68k_regset_get(struct task_struct *target,
297 const struct user_regset *regset,
298 struct membuf to)
299 {
300 struct pt_regs *ptregs = task_pt_regs(target);
301 u32 uregs[ELF_NGREG];
302
303 ELF_CORE_COPY_REGS(uregs, ptregs);
304 return membuf_write(&to, uregs, sizeof(uregs));
305 }
306
307 enum m68k_regset {
308 REGSET_GPR,
309 #ifdef CONFIG_FPU
310 REGSET_FPU,
311 #endif
312 };
313
314 static const struct user_regset m68k_user_regsets[] = {
315 [REGSET_GPR] = {
316 .core_note_type = NT_PRSTATUS,
317 .n = ELF_NGREG,
318 .size = sizeof(u32),
319 .align = sizeof(u16),
320 .regset_get = m68k_regset_get,
321 },
322 #ifdef CONFIG_FPU
323 [REGSET_FPU] = {
324 .core_note_type = NT_PRFPREG,
325 .n = sizeof(struct user_m68kfp_struct) / sizeof(u32),
326 .size = sizeof(u32),
327 .align = sizeof(u32),
328 }
329 #endif /* CONFIG_FPU */
330 };
331
332 static const struct user_regset_view user_m68k_view = {
333 .name = "m68k",
334 .e_machine = EM_68K,
335 .ei_osabi = ELF_OSABI,
336 .regsets = m68k_user_regsets,
337 .n = ARRAY_SIZE(m68k_user_regsets)
338 };
339
task_user_regset_view(struct task_struct * task)340 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
341 {
342 return &user_m68k_view;
343 }
344 #endif /* CONFIG_BINFMT_ELF_FDPIC && CONFIG_ELF_CORE */
345
