xref: /openbmc/linux/arch/arc/kernel/ptrace.c (revision 9cfc5c90)
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/regset.h>
12 #include <linux/unistd.h>
13 #include <linux/elf.h>
14 
15 static struct callee_regs *task_callee_regs(struct task_struct *tsk)
16 {
17 	struct callee_regs *tmp = (struct callee_regs *)tsk->thread.callee_reg;
18 	return tmp;
19 }
20 
21 static int genregs_get(struct task_struct *target,
22 		       const struct user_regset *regset,
23 		       unsigned int pos, unsigned int count,
24 		       void *kbuf, void __user *ubuf)
25 {
26 	const struct pt_regs *ptregs = task_pt_regs(target);
27 	const struct callee_regs *cregs = task_callee_regs(target);
28 	int ret = 0;
29 	unsigned int stop_pc_val;
30 
31 #define REG_O_CHUNK(START, END, PTR)	\
32 	if (!ret)	\
33 		ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, PTR, \
34 			offsetof(struct user_regs_struct, START), \
35 			offsetof(struct user_regs_struct, END));
36 
37 #define REG_O_ONE(LOC, PTR)	\
38 	if (!ret)		\
39 		ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf, PTR, \
40 			offsetof(struct user_regs_struct, LOC), \
41 			offsetof(struct user_regs_struct, LOC) + 4);
42 
43 #define REG_O_ZERO(LOC)		\
44 	if (!ret)		\
45 		ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf, \
46 			offsetof(struct user_regs_struct, LOC), \
47 			offsetof(struct user_regs_struct, LOC) + 4);
48 
49 	REG_O_ZERO(pad);
50 	REG_O_ONE(scratch.bta, &ptregs->bta);
51 	REG_O_ONE(scratch.lp_start, &ptregs->lp_start);
52 	REG_O_ONE(scratch.lp_end, &ptregs->lp_end);
53 	REG_O_ONE(scratch.lp_count, &ptregs->lp_count);
54 	REG_O_ONE(scratch.status32, &ptregs->status32);
55 	REG_O_ONE(scratch.ret, &ptregs->ret);
56 	REG_O_ONE(scratch.blink, &ptregs->blink);
57 	REG_O_ONE(scratch.fp, &ptregs->fp);
58 	REG_O_ONE(scratch.gp, &ptregs->r26);
59 	REG_O_ONE(scratch.r12, &ptregs->r12);
60 	REG_O_ONE(scratch.r11, &ptregs->r11);
61 	REG_O_ONE(scratch.r10, &ptregs->r10);
62 	REG_O_ONE(scratch.r9, &ptregs->r9);
63 	REG_O_ONE(scratch.r8, &ptregs->r8);
64 	REG_O_ONE(scratch.r7, &ptregs->r7);
65 	REG_O_ONE(scratch.r6, &ptregs->r6);
66 	REG_O_ONE(scratch.r5, &ptregs->r5);
67 	REG_O_ONE(scratch.r4, &ptregs->r4);
68 	REG_O_ONE(scratch.r3, &ptregs->r3);
69 	REG_O_ONE(scratch.r2, &ptregs->r2);
70 	REG_O_ONE(scratch.r1, &ptregs->r1);
71 	REG_O_ONE(scratch.r0, &ptregs->r0);
72 	REG_O_ONE(scratch.sp, &ptregs->sp);
73 
74 	REG_O_ZERO(pad2);
75 
76 	REG_O_ONE(callee.r25, &cregs->r25);
77 	REG_O_ONE(callee.r24, &cregs->r24);
78 	REG_O_ONE(callee.r23, &cregs->r23);
79 	REG_O_ONE(callee.r22, &cregs->r22);
80 	REG_O_ONE(callee.r21, &cregs->r21);
81 	REG_O_ONE(callee.r20, &cregs->r20);
82 	REG_O_ONE(callee.r19, &cregs->r19);
83 	REG_O_ONE(callee.r18, &cregs->r18);
84 	REG_O_ONE(callee.r17, &cregs->r17);
85 	REG_O_ONE(callee.r16, &cregs->r16);
86 	REG_O_ONE(callee.r15, &cregs->r15);
87 	REG_O_ONE(callee.r14, &cregs->r14);
88 	REG_O_ONE(callee.r13, &cregs->r13);
89 
90 	REG_O_ONE(efa, &target->thread.fault_address);
91 
92 	if (!ret) {
93 		if (in_brkpt_trap(ptregs)) {
94 			stop_pc_val = target->thread.fault_address;
95 			pr_debug("\t\tstop_pc (brk-pt)\n");
96 		} else {
97 			stop_pc_val = ptregs->ret;
98 			pr_debug("\t\tstop_pc (others)\n");
99 		}
100 
101 		REG_O_ONE(stop_pc, &stop_pc_val);
102 	}
103 
104 	return ret;
105 }
106 
107 static int genregs_set(struct task_struct *target,
108 		       const struct user_regset *regset,
109 		       unsigned int pos, unsigned int count,
110 		       const void *kbuf, const void __user *ubuf)
111 {
112 	const struct pt_regs *ptregs = task_pt_regs(target);
113 	const struct callee_regs *cregs = task_callee_regs(target);
114 	int ret = 0;
115 
116 #define REG_IN_CHUNK(FIRST, NEXT, PTR)	\
117 	if (!ret)			\
118 		ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, \
119 			(void *)(PTR), \
120 			offsetof(struct user_regs_struct, FIRST), \
121 			offsetof(struct user_regs_struct, NEXT));
122 
123 #define REG_IN_ONE(LOC, PTR)		\
124 	if (!ret)			\
125 		ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf, \
126 			(void *)(PTR), \
127 			offsetof(struct user_regs_struct, LOC), \
128 			offsetof(struct user_regs_struct, LOC) + 4);
129 
130 #define REG_IGNORE_ONE(LOC)		\
131 	if (!ret)			\
132 		ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf, \
133 			offsetof(struct user_regs_struct, LOC), \
134 			offsetof(struct user_regs_struct, LOC) + 4);
135 
136 	REG_IGNORE_ONE(pad);
137 
138 	REG_IN_ONE(scratch.bta, &ptregs->bta);
139 	REG_IN_ONE(scratch.lp_start, &ptregs->lp_start);
140 	REG_IN_ONE(scratch.lp_end, &ptregs->lp_end);
141 	REG_IN_ONE(scratch.lp_count, &ptregs->lp_count);
142 
143 	REG_IGNORE_ONE(scratch.status32);
144 
145 	REG_IN_ONE(scratch.ret, &ptregs->ret);
146 	REG_IN_ONE(scratch.blink, &ptregs->blink);
147 	REG_IN_ONE(scratch.fp, &ptregs->fp);
148 	REG_IN_ONE(scratch.gp, &ptregs->r26);
149 	REG_IN_ONE(scratch.r12, &ptregs->r12);
150 	REG_IN_ONE(scratch.r11, &ptregs->r11);
151 	REG_IN_ONE(scratch.r10, &ptregs->r10);
152 	REG_IN_ONE(scratch.r9, &ptregs->r9);
153 	REG_IN_ONE(scratch.r8, &ptregs->r8);
154 	REG_IN_ONE(scratch.r7, &ptregs->r7);
155 	REG_IN_ONE(scratch.r6, &ptregs->r6);
156 	REG_IN_ONE(scratch.r5, &ptregs->r5);
157 	REG_IN_ONE(scratch.r4, &ptregs->r4);
158 	REG_IN_ONE(scratch.r3, &ptregs->r3);
159 	REG_IN_ONE(scratch.r2, &ptregs->r2);
160 	REG_IN_ONE(scratch.r1, &ptregs->r1);
161 	REG_IN_ONE(scratch.r0, &ptregs->r0);
162 	REG_IN_ONE(scratch.sp, &ptregs->sp);
163 
164 	REG_IGNORE_ONE(pad2);
165 
166 	REG_IN_ONE(callee.r25, &cregs->r25);
167 	REG_IN_ONE(callee.r24, &cregs->r24);
168 	REG_IN_ONE(callee.r23, &cregs->r23);
169 	REG_IN_ONE(callee.r22, &cregs->r22);
170 	REG_IN_ONE(callee.r21, &cregs->r21);
171 	REG_IN_ONE(callee.r20, &cregs->r20);
172 	REG_IN_ONE(callee.r19, &cregs->r19);
173 	REG_IN_ONE(callee.r18, &cregs->r18);
174 	REG_IN_ONE(callee.r17, &cregs->r17);
175 	REG_IN_ONE(callee.r16, &cregs->r16);
176 	REG_IN_ONE(callee.r15, &cregs->r15);
177 	REG_IN_ONE(callee.r14, &cregs->r14);
178 	REG_IN_ONE(callee.r13, &cregs->r13);
179 
180 	REG_IGNORE_ONE(efa);			/* efa update invalid */
181 	REG_IGNORE_ONE(stop_pc);		/* PC updated via @ret */
182 
183 	return ret;
184 }
185 
186 enum arc_getset {
187 	REGSET_GENERAL,
188 };
189 
190 static const struct user_regset arc_regsets[] = {
191 	[REGSET_GENERAL] = {
192 	       .core_note_type = NT_PRSTATUS,
193 	       .n = ELF_NGREG,
194 	       .size = sizeof(unsigned long),
195 	       .align = sizeof(unsigned long),
196 	       .get = genregs_get,
197 	       .set = genregs_set,
198 	}
199 };
200 
201 static const struct user_regset_view user_arc_view = {
202 	.name		= UTS_MACHINE,
203 	.e_machine	= EM_ARC_INUSE,
204 	.regsets	= arc_regsets,
205 	.n		= ARRAY_SIZE(arc_regsets)
206 };
207 
208 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
209 {
210 	return &user_arc_view;
211 }
212 
213 void ptrace_disable(struct task_struct *child)
214 {
215 }
216 
217 long arch_ptrace(struct task_struct *child, long request,
218 		 unsigned long addr, unsigned long data)
219 {
220 	int ret = -EIO;
221 
222 	pr_debug("REQ=%ld: ADDR =0x%lx, DATA=0x%lx)\n", request, addr, data);
223 
224 	switch (request) {
225 	case PTRACE_GET_THREAD_AREA:
226 		ret = put_user(task_thread_info(child)->thr_ptr,
227 			       (unsigned long __user *)data);
228 		break;
229 	default:
230 		ret = ptrace_request(child, request, addr, data);
231 		break;
232 	}
233 
234 	return ret;
235 }
236 
237 asmlinkage int syscall_trace_entry(struct pt_regs *regs)
238 {
239 	if (tracehook_report_syscall_entry(regs))
240 		return ULONG_MAX;
241 
242 	return regs->r8;
243 }
244 
245 asmlinkage void syscall_trace_exit(struct pt_regs *regs)
246 {
247 	tracehook_report_syscall_exit(regs, 0);
248 }
249