xref: /openbmc/linux/arch/arc/kernel/ptrace.c (revision e3b9f1e8)
1 /*
2  * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
3  *
4  * This program is free software; you can redistribute it and/or modify
5  * it under the terms of the GNU General Public License version 2 as
6  * published by the Free Software Foundation.
7  */
8 
9 #include <linux/ptrace.h>
10 #include <linux/tracehook.h>
11 #include <linux/sched/task_stack.h>
12 #include <linux/regset.h>
13 #include <linux/unistd.h>
14 #include <linux/elf.h>
15 
16 static struct callee_regs *task_callee_regs(struct task_struct *tsk)
17 {
18 	struct callee_regs *tmp = (struct callee_regs *)tsk->thread.callee_reg;
19 	return tmp;
20 }
21 
22 static int genregs_get(struct task_struct *target,
23 		       const struct user_regset *regset,
24 		       unsigned int pos, unsigned int count,
25 		       void *kbuf, void __user *ubuf)
26 {
27 	const struct pt_regs *ptregs = task_pt_regs(target);
28 	const struct callee_regs *cregs = task_callee_regs(target);
29 	int ret = 0;
30 	unsigned int stop_pc_val;
31 
32 #define REG_O_CHUNK(START, END, PTR)	\
33 	if (!ret)	\
34 		ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, PTR, \
35 			offsetof(struct user_regs_struct, START), \
36 			offsetof(struct user_regs_struct, END));
37 
38 #define REG_O_ONE(LOC, PTR)	\
39 	if (!ret)		\
40 		ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, PTR, \
41 			offsetof(struct user_regs_struct, LOC), \
42 			offsetof(struct user_regs_struct, LOC) + 4);
43 
44 #define REG_O_ZERO(LOC)		\
45 	if (!ret)		\
46 		ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf, \
47 			offsetof(struct user_regs_struct, LOC), \
48 			offsetof(struct user_regs_struct, LOC) + 4);
49 
50 	REG_O_ZERO(pad);
51 	REG_O_ONE(scratch.bta, &ptregs->bta);
52 	REG_O_ONE(scratch.lp_start, &ptregs->lp_start);
53 	REG_O_ONE(scratch.lp_end, &ptregs->lp_end);
54 	REG_O_ONE(scratch.lp_count, &ptregs->lp_count);
55 	REG_O_ONE(scratch.status32, &ptregs->status32);
56 	REG_O_ONE(scratch.ret, &ptregs->ret);
57 	REG_O_ONE(scratch.blink, &ptregs->blink);
58 	REG_O_ONE(scratch.fp, &ptregs->fp);
59 	REG_O_ONE(scratch.gp, &ptregs->r26);
60 	REG_O_ONE(scratch.r12, &ptregs->r12);
61 	REG_O_ONE(scratch.r11, &ptregs->r11);
62 	REG_O_ONE(scratch.r10, &ptregs->r10);
63 	REG_O_ONE(scratch.r9, &ptregs->r9);
64 	REG_O_ONE(scratch.r8, &ptregs->r8);
65 	REG_O_ONE(scratch.r7, &ptregs->r7);
66 	REG_O_ONE(scratch.r6, &ptregs->r6);
67 	REG_O_ONE(scratch.r5, &ptregs->r5);
68 	REG_O_ONE(scratch.r4, &ptregs->r4);
69 	REG_O_ONE(scratch.r3, &ptregs->r3);
70 	REG_O_ONE(scratch.r2, &ptregs->r2);
71 	REG_O_ONE(scratch.r1, &ptregs->r1);
72 	REG_O_ONE(scratch.r0, &ptregs->r0);
73 	REG_O_ONE(scratch.sp, &ptregs->sp);
74 
75 	REG_O_ZERO(pad2);
76 
77 	REG_O_ONE(callee.r25, &cregs->r25);
78 	REG_O_ONE(callee.r24, &cregs->r24);
79 	REG_O_ONE(callee.r23, &cregs->r23);
80 	REG_O_ONE(callee.r22, &cregs->r22);
81 	REG_O_ONE(callee.r21, &cregs->r21);
82 	REG_O_ONE(callee.r20, &cregs->r20);
83 	REG_O_ONE(callee.r19, &cregs->r19);
84 	REG_O_ONE(callee.r18, &cregs->r18);
85 	REG_O_ONE(callee.r17, &cregs->r17);
86 	REG_O_ONE(callee.r16, &cregs->r16);
87 	REG_O_ONE(callee.r15, &cregs->r15);
88 	REG_O_ONE(callee.r14, &cregs->r14);
89 	REG_O_ONE(callee.r13, &cregs->r13);
90 
91 	REG_O_ONE(efa, &target->thread.fault_address);
92 
93 	if (!ret) {
94 		if (in_brkpt_trap(ptregs)) {
95 			stop_pc_val = target->thread.fault_address;
96 			pr_debug("\t\tstop_pc (brk-pt)\n");
97 		} else {
98 			stop_pc_val = ptregs->ret;
99 			pr_debug("\t\tstop_pc (others)\n");
100 		}
101 
102 		REG_O_ONE(stop_pc, &stop_pc_val);
103 	}
104 
105 	return ret;
106 }
107 
108 static int genregs_set(struct task_struct *target,
109 		       const struct user_regset *regset,
110 		       unsigned int pos, unsigned int count,
111 		       const void *kbuf, const void __user *ubuf)
112 {
113 	const struct pt_regs *ptregs = task_pt_regs(target);
114 	const struct callee_regs *cregs = task_callee_regs(target);
115 	int ret = 0;
116 
117 #define REG_IN_CHUNK(FIRST, NEXT, PTR)	\
118 	if (!ret)			\
119 		ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, \
120 			(void *)(PTR), \
121 			offsetof(struct user_regs_struct, FIRST), \
122 			offsetof(struct user_regs_struct, NEXT));
123 
124 #define REG_IN_ONE(LOC, PTR)		\
125 	if (!ret)			\
126 		ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, \
127 			(void *)(PTR), \
128 			offsetof(struct user_regs_struct, LOC), \
129 			offsetof(struct user_regs_struct, LOC) + 4);
130 
131 #define REG_IGNORE_ONE(LOC)		\
132 	if (!ret)			\
133 		ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf, \
134 			offsetof(struct user_regs_struct, LOC), \
135 			offsetof(struct user_regs_struct, LOC) + 4);
136 
137 	REG_IGNORE_ONE(pad);
138 
139 	REG_IN_ONE(scratch.bta, &ptregs->bta);
140 	REG_IN_ONE(scratch.lp_start, &ptregs->lp_start);
141 	REG_IN_ONE(scratch.lp_end, &ptregs->lp_end);
142 	REG_IN_ONE(scratch.lp_count, &ptregs->lp_count);
143 
144 	REG_IGNORE_ONE(scratch.status32);
145 
146 	REG_IN_ONE(scratch.ret, &ptregs->ret);
147 	REG_IN_ONE(scratch.blink, &ptregs->blink);
148 	REG_IN_ONE(scratch.fp, &ptregs->fp);
149 	REG_IN_ONE(scratch.gp, &ptregs->r26);
150 	REG_IN_ONE(scratch.r12, &ptregs->r12);
151 	REG_IN_ONE(scratch.r11, &ptregs->r11);
152 	REG_IN_ONE(scratch.r10, &ptregs->r10);
153 	REG_IN_ONE(scratch.r9, &ptregs->r9);
154 	REG_IN_ONE(scratch.r8, &ptregs->r8);
155 	REG_IN_ONE(scratch.r7, &ptregs->r7);
156 	REG_IN_ONE(scratch.r6, &ptregs->r6);
157 	REG_IN_ONE(scratch.r5, &ptregs->r5);
158 	REG_IN_ONE(scratch.r4, &ptregs->r4);
159 	REG_IN_ONE(scratch.r3, &ptregs->r3);
160 	REG_IN_ONE(scratch.r2, &ptregs->r2);
161 	REG_IN_ONE(scratch.r1, &ptregs->r1);
162 	REG_IN_ONE(scratch.r0, &ptregs->r0);
163 	REG_IN_ONE(scratch.sp, &ptregs->sp);
164 
165 	REG_IGNORE_ONE(pad2);
166 
167 	REG_IN_ONE(callee.r25, &cregs->r25);
168 	REG_IN_ONE(callee.r24, &cregs->r24);
169 	REG_IN_ONE(callee.r23, &cregs->r23);
170 	REG_IN_ONE(callee.r22, &cregs->r22);
171 	REG_IN_ONE(callee.r21, &cregs->r21);
172 	REG_IN_ONE(callee.r20, &cregs->r20);
173 	REG_IN_ONE(callee.r19, &cregs->r19);
174 	REG_IN_ONE(callee.r18, &cregs->r18);
175 	REG_IN_ONE(callee.r17, &cregs->r17);
176 	REG_IN_ONE(callee.r16, &cregs->r16);
177 	REG_IN_ONE(callee.r15, &cregs->r15);
178 	REG_IN_ONE(callee.r14, &cregs->r14);
179 	REG_IN_ONE(callee.r13, &cregs->r13);
180 
181 	REG_IGNORE_ONE(efa);			/* efa update invalid */
182 	REG_IGNORE_ONE(stop_pc);		/* PC updated via @ret */
183 
184 	return ret;
185 }
186 
187 #ifdef CONFIG_ISA_ARCV2
188 static int arcv2regs_get(struct task_struct *target,
189 		       const struct user_regset *regset,
190 		       unsigned int pos, unsigned int count,
191 		       void *kbuf, void __user *ubuf)
192 {
193 	const struct pt_regs *regs = task_pt_regs(target);
194 	int ret, copy_sz;
195 
196 	if (IS_ENABLED(CONFIG_ARC_HAS_ACCL_REGS))
197 		copy_sz = sizeof(struct user_regs_arcv2);
198 	else
199 		copy_sz = 4;	/* r30 only */
200 
201 	/*
202 	 * itemized copy not needed like above as layout of regs (r30,r58,r59)
203 	 * is exactly same in kernel (pt_regs) and userspace (user_regs_arcv2)
204 	 */
205 	ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, &regs->r30,
206 				  0, copy_sz);
207 
208 	return ret;
209 }
210 
211 static int arcv2regs_set(struct task_struct *target,
212 		       const struct user_regset *regset,
213 		       unsigned int pos, unsigned int count,
214 		       const void *kbuf, const void __user *ubuf)
215 {
216 	const struct pt_regs *regs = task_pt_regs(target);
217 	int ret, copy_sz;
218 
219 	if (IS_ENABLED(CONFIG_ARC_HAS_ACCL_REGS))
220 		copy_sz = sizeof(struct user_regs_arcv2);
221 	else
222 		copy_sz = 4;	/* r30 only */
223 
224 	ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, (void *)&regs->r30,
225 				  0, copy_sz);
226 
227 	return ret;
228 }
229 
230 #endif
231 
232 enum arc_getset {
233 	REGSET_CMN,
234 	REGSET_ARCV2,
235 };
236 
237 static const struct user_regset arc_regsets[] = {
238 	[REGSET_CMN] = {
239 	       .core_note_type = NT_PRSTATUS,
240 	       .n = ELF_NGREG,
241 	       .size = sizeof(unsigned long),
242 	       .align = sizeof(unsigned long),
243 	       .get = genregs_get,
244 	       .set = genregs_set,
245 	},
246 #ifdef CONFIG_ISA_ARCV2
247 	[REGSET_ARCV2] = {
248 	       .core_note_type = NT_ARC_V2,
249 	       .n = ELF_ARCV2REG,
250 	       .size = sizeof(unsigned long),
251 	       .align = sizeof(unsigned long),
252 	       .get = arcv2regs_get,
253 	       .set = arcv2regs_set,
254 	},
255 #endif
256 };
257 
258 static const struct user_regset_view user_arc_view = {
259 	.name		= UTS_MACHINE,
260 	.e_machine	= EM_ARC_INUSE,
261 	.regsets	= arc_regsets,
262 	.n		= ARRAY_SIZE(arc_regsets)
263 };
264 
265 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
266 {
267 	return &user_arc_view;
268 }
269 
270 void ptrace_disable(struct task_struct *child)
271 {
272 }
273 
274 long arch_ptrace(struct task_struct *child, long request,
275 		 unsigned long addr, unsigned long data)
276 {
277 	int ret = -EIO;
278 
279 	pr_debug("REQ=%ld: ADDR =0x%lx, DATA=0x%lx)\n", request, addr, data);
280 
281 	switch (request) {
282 	case PTRACE_GET_THREAD_AREA:
283 		ret = put_user(task_thread_info(child)->thr_ptr,
284 			       (unsigned long __user *)data);
285 		break;
286 	default:
287 		ret = ptrace_request(child, request, addr, data);
288 		break;
289 	}
290 
291 	return ret;
292 }
293 
294 asmlinkage int syscall_trace_entry(struct pt_regs *regs)
295 {
296 	if (tracehook_report_syscall_entry(regs))
297 		return ULONG_MAX;
298 
299 	return regs->r8;
300 }
301 
302 asmlinkage void syscall_trace_exit(struct pt_regs *regs)
303 {
304 	tracehook_report_syscall_exit(regs, 0);
305 }
306