xref: /openbmc/linux/arch/arc/kernel/ptrace.c (revision 3ce311af)
1 // SPDX-License-Identifier: GPL-2.0-only
2 /*
3  * Copyright (C) 2004, 2007-2010, 2011-2012 Synopsys, Inc. (www.synopsys.com)
4  */
5 
6 #include <linux/ptrace.h>
7 #include <linux/tracehook.h>
8 #include <linux/sched/task_stack.h>
9 #include <linux/regset.h>
10 #include <linux/unistd.h>
11 #include <linux/elf.h>
12 
13 static struct callee_regs *task_callee_regs(struct task_struct *tsk)
14 {
15 	struct callee_regs *tmp = (struct callee_regs *)tsk->thread.callee_reg;
16 	return tmp;
17 }
18 
19 static int genregs_get(struct task_struct *target,
20 		       const struct user_regset *regset,
21 		       unsigned int pos, unsigned int count,
22 		       void *kbuf, void __user *ubuf)
23 {
24 	const struct pt_regs *ptregs = task_pt_regs(target);
25 	const struct callee_regs *cregs = task_callee_regs(target);
26 	int ret = 0;
27 	unsigned int stop_pc_val;
28 
29 #define REG_O_CHUNK(START, END, PTR)	\
30 	if (!ret)	\
31 		ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, PTR, \
32 			offsetof(struct user_regs_struct, START), \
33 			offsetof(struct user_regs_struct, END));
34 
35 #define REG_O_ONE(LOC, PTR)	\
36 	if (!ret)		\
37 		ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, PTR, \
38 			offsetof(struct user_regs_struct, LOC), \
39 			offsetof(struct user_regs_struct, LOC) + 4);
40 
41 #define REG_O_ZERO(LOC)		\
42 	if (!ret)		\
43 		ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf, \
44 			offsetof(struct user_regs_struct, LOC), \
45 			offsetof(struct user_regs_struct, LOC) + 4);
46 
47 	REG_O_ZERO(pad);
48 	REG_O_ONE(scratch.bta, &ptregs->bta);
49 	REG_O_ONE(scratch.lp_start, &ptregs->lp_start);
50 	REG_O_ONE(scratch.lp_end, &ptregs->lp_end);
51 	REG_O_ONE(scratch.lp_count, &ptregs->lp_count);
52 	REG_O_ONE(scratch.status32, &ptregs->status32);
53 	REG_O_ONE(scratch.ret, &ptregs->ret);
54 	REG_O_ONE(scratch.blink, &ptregs->blink);
55 	REG_O_ONE(scratch.fp, &ptregs->fp);
56 	REG_O_ONE(scratch.gp, &ptregs->r26);
57 	REG_O_ONE(scratch.r12, &ptregs->r12);
58 	REG_O_ONE(scratch.r11, &ptregs->r11);
59 	REG_O_ONE(scratch.r10, &ptregs->r10);
60 	REG_O_ONE(scratch.r9, &ptregs->r9);
61 	REG_O_ONE(scratch.r8, &ptregs->r8);
62 	REG_O_ONE(scratch.r7, &ptregs->r7);
63 	REG_O_ONE(scratch.r6, &ptregs->r6);
64 	REG_O_ONE(scratch.r5, &ptregs->r5);
65 	REG_O_ONE(scratch.r4, &ptregs->r4);
66 	REG_O_ONE(scratch.r3, &ptregs->r3);
67 	REG_O_ONE(scratch.r2, &ptregs->r2);
68 	REG_O_ONE(scratch.r1, &ptregs->r1);
69 	REG_O_ONE(scratch.r0, &ptregs->r0);
70 	REG_O_ONE(scratch.sp, &ptregs->sp);
71 
72 	REG_O_ZERO(pad2);
73 
74 	REG_O_ONE(callee.r25, &cregs->r25);
75 	REG_O_ONE(callee.r24, &cregs->r24);
76 	REG_O_ONE(callee.r23, &cregs->r23);
77 	REG_O_ONE(callee.r22, &cregs->r22);
78 	REG_O_ONE(callee.r21, &cregs->r21);
79 	REG_O_ONE(callee.r20, &cregs->r20);
80 	REG_O_ONE(callee.r19, &cregs->r19);
81 	REG_O_ONE(callee.r18, &cregs->r18);
82 	REG_O_ONE(callee.r17, &cregs->r17);
83 	REG_O_ONE(callee.r16, &cregs->r16);
84 	REG_O_ONE(callee.r15, &cregs->r15);
85 	REG_O_ONE(callee.r14, &cregs->r14);
86 	REG_O_ONE(callee.r13, &cregs->r13);
87 
88 	REG_O_ONE(efa, &target->thread.fault_address);
89 
90 	if (!ret) {
91 		if (in_brkpt_trap(ptregs)) {
92 			stop_pc_val = target->thread.fault_address;
93 			pr_debug("\t\tstop_pc (brk-pt)\n");
94 		} else {
95 			stop_pc_val = ptregs->ret;
96 			pr_debug("\t\tstop_pc (others)\n");
97 		}
98 
99 		REG_O_ONE(stop_pc, &stop_pc_val);
100 	}
101 
102 	return ret;
103 }
104 
105 static int genregs_set(struct task_struct *target,
106 		       const struct user_regset *regset,
107 		       unsigned int pos, unsigned int count,
108 		       const void *kbuf, const void __user *ubuf)
109 {
110 	const struct pt_regs *ptregs = task_pt_regs(target);
111 	const struct callee_regs *cregs = task_callee_regs(target);
112 	int ret = 0;
113 
114 #define REG_IN_CHUNK(FIRST, NEXT, PTR)	\
115 	if (!ret)			\
116 		ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, \
117 			(void *)(PTR), \
118 			offsetof(struct user_regs_struct, FIRST), \
119 			offsetof(struct user_regs_struct, NEXT));
120 
121 #define REG_IN_ONE(LOC, PTR)		\
122 	if (!ret)			\
123 		ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, \
124 			(void *)(PTR), \
125 			offsetof(struct user_regs_struct, LOC), \
126 			offsetof(struct user_regs_struct, LOC) + 4);
127 
128 #define REG_IGNORE_ONE(LOC)		\
129 	if (!ret)			\
130 		ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf, \
131 			offsetof(struct user_regs_struct, LOC), \
132 			offsetof(struct user_regs_struct, LOC) + 4);
133 
134 	REG_IGNORE_ONE(pad);
135 
136 	REG_IN_ONE(scratch.bta, &ptregs->bta);
137 	REG_IN_ONE(scratch.lp_start, &ptregs->lp_start);
138 	REG_IN_ONE(scratch.lp_end, &ptregs->lp_end);
139 	REG_IN_ONE(scratch.lp_count, &ptregs->lp_count);
140 
141 	REG_IGNORE_ONE(scratch.status32);
142 
143 	REG_IN_ONE(scratch.ret, &ptregs->ret);
144 	REG_IN_ONE(scratch.blink, &ptregs->blink);
145 	REG_IN_ONE(scratch.fp, &ptregs->fp);
146 	REG_IN_ONE(scratch.gp, &ptregs->r26);
147 	REG_IN_ONE(scratch.r12, &ptregs->r12);
148 	REG_IN_ONE(scratch.r11, &ptregs->r11);
149 	REG_IN_ONE(scratch.r10, &ptregs->r10);
150 	REG_IN_ONE(scratch.r9, &ptregs->r9);
151 	REG_IN_ONE(scratch.r8, &ptregs->r8);
152 	REG_IN_ONE(scratch.r7, &ptregs->r7);
153 	REG_IN_ONE(scratch.r6, &ptregs->r6);
154 	REG_IN_ONE(scratch.r5, &ptregs->r5);
155 	REG_IN_ONE(scratch.r4, &ptregs->r4);
156 	REG_IN_ONE(scratch.r3, &ptregs->r3);
157 	REG_IN_ONE(scratch.r2, &ptregs->r2);
158 	REG_IN_ONE(scratch.r1, &ptregs->r1);
159 	REG_IN_ONE(scratch.r0, &ptregs->r0);
160 	REG_IN_ONE(scratch.sp, &ptregs->sp);
161 
162 	REG_IGNORE_ONE(pad2);
163 
164 	REG_IN_ONE(callee.r25, &cregs->r25);
165 	REG_IN_ONE(callee.r24, &cregs->r24);
166 	REG_IN_ONE(callee.r23, &cregs->r23);
167 	REG_IN_ONE(callee.r22, &cregs->r22);
168 	REG_IN_ONE(callee.r21, &cregs->r21);
169 	REG_IN_ONE(callee.r20, &cregs->r20);
170 	REG_IN_ONE(callee.r19, &cregs->r19);
171 	REG_IN_ONE(callee.r18, &cregs->r18);
172 	REG_IN_ONE(callee.r17, &cregs->r17);
173 	REG_IN_ONE(callee.r16, &cregs->r16);
174 	REG_IN_ONE(callee.r15, &cregs->r15);
175 	REG_IN_ONE(callee.r14, &cregs->r14);
176 	REG_IN_ONE(callee.r13, &cregs->r13);
177 
178 	REG_IGNORE_ONE(efa);			/* efa update invalid */
179 	REG_IGNORE_ONE(stop_pc);		/* PC updated via @ret */
180 
181 	return ret;
182 }
183 
184 #ifdef CONFIG_ISA_ARCV2
185 static int arcv2regs_get(struct task_struct *target,
186 		       const struct user_regset *regset,
187 		       unsigned int pos, unsigned int count,
188 		       void *kbuf, void __user *ubuf)
189 {
190 	const struct pt_regs *regs = task_pt_regs(target);
191 	int ret, copy_sz;
192 
193 	if (IS_ENABLED(CONFIG_ARC_HAS_ACCL_REGS))
194 		copy_sz = sizeof(struct user_regs_arcv2);
195 	else
196 		copy_sz = 4;	/* r30 only */
197 
198 	/*
199 	 * itemized copy not needed like above as layout of regs (r30,r58,r59)
200 	 * is exactly same in kernel (pt_regs) and userspace (user_regs_arcv2)
201 	 */
202 	ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, &regs->r30,
203 				  0, copy_sz);
204 
205 	return ret;
206 }
207 
208 static int arcv2regs_set(struct task_struct *target,
209 		       const struct user_regset *regset,
210 		       unsigned int pos, unsigned int count,
211 		       const void *kbuf, const void __user *ubuf)
212 {
213 	const struct pt_regs *regs = task_pt_regs(target);
214 	int ret, copy_sz;
215 
216 	if (IS_ENABLED(CONFIG_ARC_HAS_ACCL_REGS))
217 		copy_sz = sizeof(struct user_regs_arcv2);
218 	else
219 		copy_sz = 4;	/* r30 only */
220 
221 	ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, (void *)&regs->r30,
222 				  0, copy_sz);
223 
224 	return ret;
225 }
226 
227 #endif
228 
229 enum arc_getset {
230 	REGSET_CMN,
231 	REGSET_ARCV2,
232 };
233 
234 static const struct user_regset arc_regsets[] = {
235 	[REGSET_CMN] = {
236 	       .core_note_type = NT_PRSTATUS,
237 	       .n = ELF_NGREG,
238 	       .size = sizeof(unsigned long),
239 	       .align = sizeof(unsigned long),
240 	       .get = genregs_get,
241 	       .set = genregs_set,
242 	},
243 #ifdef CONFIG_ISA_ARCV2
244 	[REGSET_ARCV2] = {
245 	       .core_note_type = NT_ARC_V2,
246 	       .n = ELF_ARCV2REG,
247 	       .size = sizeof(unsigned long),
248 	       .align = sizeof(unsigned long),
249 	       .get = arcv2regs_get,
250 	       .set = arcv2regs_set,
251 	},
252 #endif
253 };
254 
255 static const struct user_regset_view user_arc_view = {
256 	.name		= UTS_MACHINE,
257 	.e_machine	= EM_ARC_INUSE,
258 	.regsets	= arc_regsets,
259 	.n		= ARRAY_SIZE(arc_regsets)
260 };
261 
262 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
263 {
264 	return &user_arc_view;
265 }
266 
267 void ptrace_disable(struct task_struct *child)
268 {
269 }
270 
271 long arch_ptrace(struct task_struct *child, long request,
272 		 unsigned long addr, unsigned long data)
273 {
274 	int ret = -EIO;
275 
276 	pr_debug("REQ=%ld: ADDR =0x%lx, DATA=0x%lx)\n", request, addr, data);
277 
278 	switch (request) {
279 	case PTRACE_GET_THREAD_AREA:
280 		ret = put_user(task_thread_info(child)->thr_ptr,
281 			       (unsigned long __user *)data);
282 		break;
283 	default:
284 		ret = ptrace_request(child, request, addr, data);
285 		break;
286 	}
287 
288 	return ret;
289 }
290 
291 asmlinkage int syscall_trace_entry(struct pt_regs *regs)
292 {
293 	if (tracehook_report_syscall_entry(regs))
294 		return ULONG_MAX;
295 
296 	return regs->r8;
297 }
298 
299 asmlinkage void syscall_trace_exit(struct pt_regs *regs)
300 {
301 	tracehook_report_syscall_exit(regs, 0);
302 }
303