xref: /openbmc/linux/arch/arc/kernel/ptrace.c (revision e15a5365)
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 		       struct membuf to)
22 {
23 	const struct pt_regs *ptregs = task_pt_regs(target);
24 	const struct callee_regs *cregs = task_callee_regs(target);
25 	unsigned int stop_pc_val;
26 
27 	membuf_zero(&to, 4);	// pad
28 	membuf_store(&to, ptregs->bta);
29 	membuf_store(&to, ptregs->lp_start);
30 	membuf_store(&to, ptregs->lp_end);
31 	membuf_store(&to, ptregs->lp_count);
32 	membuf_store(&to, ptregs->status32);
33 	membuf_store(&to, ptregs->ret);
34 	membuf_store(&to, ptregs->blink);
35 	membuf_store(&to, ptregs->fp);
36 	membuf_store(&to, ptregs->r26);	// gp
37 	membuf_store(&to, ptregs->r12);
38 	membuf_store(&to, ptregs->r11);
39 	membuf_store(&to, ptregs->r10);
40 	membuf_store(&to, ptregs->r9);
41 	membuf_store(&to, ptregs->r8);
42 	membuf_store(&to, ptregs->r7);
43 	membuf_store(&to, ptregs->r6);
44 	membuf_store(&to, ptregs->r5);
45 	membuf_store(&to, ptregs->r4);
46 	membuf_store(&to, ptregs->r3);
47 	membuf_store(&to, ptregs->r2);
48 	membuf_store(&to, ptregs->r1);
49 	membuf_store(&to, ptregs->r0);
50 	membuf_store(&to, ptregs->sp);
51 	membuf_zero(&to, 4);	// pad2
52 	membuf_store(&to, cregs->r25);
53 	membuf_store(&to, cregs->r24);
54 	membuf_store(&to, cregs->r23);
55 	membuf_store(&to, cregs->r22);
56 	membuf_store(&to, cregs->r21);
57 	membuf_store(&to, cregs->r20);
58 	membuf_store(&to, cregs->r19);
59 	membuf_store(&to, cregs->r18);
60 	membuf_store(&to, cregs->r17);
61 	membuf_store(&to, cregs->r16);
62 	membuf_store(&to, cregs->r15);
63 	membuf_store(&to, cregs->r14);
64 	membuf_store(&to, cregs->r13);
65 	membuf_store(&to, target->thread.fault_address); // efa
66 
67 	if (in_brkpt_trap(ptregs)) {
68 		stop_pc_val = target->thread.fault_address;
69 		pr_debug("\t\tstop_pc (brk-pt)\n");
70 	} else {
71 		stop_pc_val = ptregs->ret;
72 		pr_debug("\t\tstop_pc (others)\n");
73 	}
74 
75 	return membuf_store(&to, stop_pc_val); // stop_pc
76 }
77 
78 static int genregs_set(struct task_struct *target,
79 		       const struct user_regset *regset,
80 		       unsigned int pos, unsigned int count,
81 		       const void *kbuf, const void __user *ubuf)
82 {
83 	const struct pt_regs *ptregs = task_pt_regs(target);
84 	const struct callee_regs *cregs = task_callee_regs(target);
85 	int ret = 0;
86 
87 #define REG_IN_CHUNK(FIRST, NEXT, PTR)	\
88 	if (!ret)			\
89 		ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, \
90 			(void *)(PTR), \
91 			offsetof(struct user_regs_struct, FIRST), \
92 			offsetof(struct user_regs_struct, NEXT));
93 
94 #define REG_IN_ONE(LOC, PTR)		\
95 	if (!ret)			\
96 		ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, \
97 			(void *)(PTR), \
98 			offsetof(struct user_regs_struct, LOC), \
99 			offsetof(struct user_regs_struct, LOC) + 4);
100 
101 #define REG_IGNORE_ONE(LOC)		\
102 	if (!ret)			\
103 		ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf, \
104 			offsetof(struct user_regs_struct, LOC), \
105 			offsetof(struct user_regs_struct, LOC) + 4);
106 
107 	REG_IGNORE_ONE(pad);
108 
109 	REG_IN_ONE(scratch.bta, &ptregs->bta);
110 	REG_IN_ONE(scratch.lp_start, &ptregs->lp_start);
111 	REG_IN_ONE(scratch.lp_end, &ptregs->lp_end);
112 	REG_IN_ONE(scratch.lp_count, &ptregs->lp_count);
113 
114 	REG_IGNORE_ONE(scratch.status32);
115 
116 	REG_IN_ONE(scratch.ret, &ptregs->ret);
117 	REG_IN_ONE(scratch.blink, &ptregs->blink);
118 	REG_IN_ONE(scratch.fp, &ptregs->fp);
119 	REG_IN_ONE(scratch.gp, &ptregs->r26);
120 	REG_IN_ONE(scratch.r12, &ptregs->r12);
121 	REG_IN_ONE(scratch.r11, &ptregs->r11);
122 	REG_IN_ONE(scratch.r10, &ptregs->r10);
123 	REG_IN_ONE(scratch.r9, &ptregs->r9);
124 	REG_IN_ONE(scratch.r8, &ptregs->r8);
125 	REG_IN_ONE(scratch.r7, &ptregs->r7);
126 	REG_IN_ONE(scratch.r6, &ptregs->r6);
127 	REG_IN_ONE(scratch.r5, &ptregs->r5);
128 	REG_IN_ONE(scratch.r4, &ptregs->r4);
129 	REG_IN_ONE(scratch.r3, &ptregs->r3);
130 	REG_IN_ONE(scratch.r2, &ptregs->r2);
131 	REG_IN_ONE(scratch.r1, &ptregs->r1);
132 	REG_IN_ONE(scratch.r0, &ptregs->r0);
133 	REG_IN_ONE(scratch.sp, &ptregs->sp);
134 
135 	REG_IGNORE_ONE(pad2);
136 
137 	REG_IN_ONE(callee.r25, &cregs->r25);
138 	REG_IN_ONE(callee.r24, &cregs->r24);
139 	REG_IN_ONE(callee.r23, &cregs->r23);
140 	REG_IN_ONE(callee.r22, &cregs->r22);
141 	REG_IN_ONE(callee.r21, &cregs->r21);
142 	REG_IN_ONE(callee.r20, &cregs->r20);
143 	REG_IN_ONE(callee.r19, &cregs->r19);
144 	REG_IN_ONE(callee.r18, &cregs->r18);
145 	REG_IN_ONE(callee.r17, &cregs->r17);
146 	REG_IN_ONE(callee.r16, &cregs->r16);
147 	REG_IN_ONE(callee.r15, &cregs->r15);
148 	REG_IN_ONE(callee.r14, &cregs->r14);
149 	REG_IN_ONE(callee.r13, &cregs->r13);
150 
151 	REG_IGNORE_ONE(efa);			/* efa update invalid */
152 	REG_IGNORE_ONE(stop_pc);		/* PC updated via @ret */
153 
154 	return ret;
155 }
156 
157 #ifdef CONFIG_ISA_ARCV2
158 static int arcv2regs_get(struct task_struct *target,
159 		       const struct user_regset *regset,
160 		       struct membuf to)
161 {
162 	const struct pt_regs *regs = task_pt_regs(target);
163 
164 	if (IS_ENABLED(CONFIG_ARC_HAS_ACCL_REGS))
165 		/*
166 		 * itemized copy not needed like above as layout of regs (r30,r58,r59)
167 		 * is exactly same in kernel (pt_regs) and userspace (user_regs_arcv2)
168 		 */
169 		return membuf_write(&to, &regs->r30, sizeof(struct user_regs_arcv2));
170 
171 
172 	membuf_write(&to, &regs->r30, 4); /* r30 only */
173 	return membuf_zero(&to, sizeof(struct user_regs_arcv2) - 4);
174 }
175 
176 static int arcv2regs_set(struct task_struct *target,
177 		       const struct user_regset *regset,
178 		       unsigned int pos, unsigned int count,
179 		       const void *kbuf, const void __user *ubuf)
180 {
181 	const struct pt_regs *regs = task_pt_regs(target);
182 	int ret, copy_sz;
183 
184 	if (IS_ENABLED(CONFIG_ARC_HAS_ACCL_REGS))
185 		copy_sz = sizeof(struct user_regs_arcv2);
186 	else
187 		copy_sz = 4;	/* r30 only */
188 
189 	ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, (void *)&regs->r30,
190 				  0, copy_sz);
191 
192 	return ret;
193 }
194 
195 #endif
196 
197 enum arc_getset {
198 	REGSET_CMN,
199 	REGSET_ARCV2,
200 };
201 
202 static const struct user_regset arc_regsets[] = {
203 	[REGSET_CMN] = {
204 	       .core_note_type = NT_PRSTATUS,
205 	       .n = ELF_NGREG,
206 	       .size = sizeof(unsigned long),
207 	       .align = sizeof(unsigned long),
208 	       .regset_get = genregs_get,
209 	       .set = genregs_set,
210 	},
211 #ifdef CONFIG_ISA_ARCV2
212 	[REGSET_ARCV2] = {
213 	       .core_note_type = NT_ARC_V2,
214 	       .n = ELF_ARCV2REG,
215 	       .size = sizeof(unsigned long),
216 	       .align = sizeof(unsigned long),
217 	       .regset_get = arcv2regs_get,
218 	       .set = arcv2regs_set,
219 	},
220 #endif
221 };
222 
223 static const struct user_regset_view user_arc_view = {
224 	.name		= "arc",
225 	.e_machine	= EM_ARC_INUSE,
226 	.regsets	= arc_regsets,
227 	.n		= ARRAY_SIZE(arc_regsets)
228 };
229 
230 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
231 {
232 	return &user_arc_view;
233 }
234 
235 void ptrace_disable(struct task_struct *child)
236 {
237 }
238 
239 long arch_ptrace(struct task_struct *child, long request,
240 		 unsigned long addr, unsigned long data)
241 {
242 	int ret = -EIO;
243 
244 	pr_debug("REQ=%ld: ADDR =0x%lx, DATA=0x%lx)\n", request, addr, data);
245 
246 	switch (request) {
247 	case PTRACE_GET_THREAD_AREA:
248 		ret = put_user(task_thread_info(child)->thr_ptr,
249 			       (unsigned long __user *)data);
250 		break;
251 	default:
252 		ret = ptrace_request(child, request, addr, data);
253 		break;
254 	}
255 
256 	return ret;
257 }
258 
259 asmlinkage int syscall_trace_entry(struct pt_regs *regs)
260 {
261 	if (tracehook_report_syscall_entry(regs))
262 		return ULONG_MAX;
263 
264 	return regs->r8;
265 }
266 
267 asmlinkage void syscall_trace_exit(struct pt_regs *regs)
268 {
269 	tracehook_report_syscall_exit(regs, 0);
270 }
271