1 /*
2  * This file is subject to the terms and conditions of the GNU General Public
3  * License.  See the file "COPYING" in the main directory of this archive
4  * for more details.
5  *
6  * Copyright (C) 1992 Ross Biro
7  * Copyright (C) Linus Torvalds
8  * Copyright (C) 1994, 95, 96, 97, 98, 2000 Ralf Baechle
9  * Copyright (C) 1996 David S. Miller
10  * Kevin D. Kissell, kevink@mips.com and Carsten Langgaard, carstenl@mips.com
11  * Copyright (C) 1999 MIPS Technologies, Inc.
12  * Copyright (C) 2000 Ulf Carlsson
13  *
14  * At this time Linux/MIPS64 only supports syscall tracing, even for 32-bit
15  * binaries.
16  */
17 #include <linux/compiler.h>
18 #include <linux/compat.h>
19 #include <linux/kernel.h>
20 #include <linux/sched.h>
21 #include <linux/sched/task_stack.h>
22 #include <linux/mm.h>
23 #include <linux/errno.h>
24 #include <linux/ptrace.h>
25 #include <linux/smp.h>
26 #include <linux/security.h>
27 
28 #include <asm/cpu.h>
29 #include <asm/dsp.h>
30 #include <asm/fpu.h>
31 #include <asm/mipsregs.h>
32 #include <asm/mipsmtregs.h>
33 #include <asm/page.h>
34 #include <asm/reg.h>
35 #include <asm/syscall.h>
36 #include <linux/uaccess.h>
37 #include <asm/bootinfo.h>
38 
39 /*
40  * Tracing a 32-bit process with a 64-bit strace and vice versa will not
41  * work.  I don't know how to fix this.
42  */
compat_arch_ptrace(struct task_struct * child,compat_long_t request,compat_ulong_t caddr,compat_ulong_t cdata)43 long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
44 			compat_ulong_t caddr, compat_ulong_t cdata)
45 {
46 	int addr = caddr;
47 	int data = cdata;
48 	int ret;
49 
50 	switch (request) {
51 
52 	/*
53 	 * Read 4 bytes of the other process' storage
54 	 *  data is a pointer specifying where the user wants the
55 	 *	4 bytes copied into
56 	 *  addr is a pointer in the user's storage that contains an 8 byte
57 	 *	address in the other process of the 4 bytes that is to be read
58 	 * (this is run in a 32-bit process looking at a 64-bit process)
59 	 * when I and D space are separate, these will need to be fixed.
60 	 */
61 	case PTRACE_PEEKTEXT_3264:
62 	case PTRACE_PEEKDATA_3264: {
63 		u32 tmp;
64 		int copied;
65 		u32 __user * addrOthers;
66 
67 		ret = -EIO;
68 
69 		/* Get the addr in the other process that we want to read */
70 		if (get_user(addrOthers, (u32 __user * __user *) (unsigned long) addr) != 0)
71 			break;
72 
73 		copied = ptrace_access_vm(child, (u64)addrOthers, &tmp,
74 				sizeof(tmp), FOLL_FORCE);
75 		if (copied != sizeof(tmp))
76 			break;
77 		ret = put_user(tmp, (u32 __user *) (unsigned long) data);
78 		break;
79 	}
80 
81 	/* Read the word at location addr in the USER area. */
82 	case PTRACE_PEEKUSR: {
83 		struct pt_regs *regs;
84 		unsigned int tmp;
85 
86 		regs = task_pt_regs(child);
87 		ret = 0;  /* Default return value. */
88 
89 		switch (addr) {
90 		case 0 ... 31:
91 			tmp = regs->regs[addr];
92 			break;
93 #ifdef CONFIG_MIPS_FP_SUPPORT
94 		case FPR_BASE ... FPR_BASE + 31: {
95 			union fpureg *fregs;
96 
97 			if (!tsk_used_math(child)) {
98 				/* FP not yet used */
99 				tmp = -1;
100 				break;
101 			}
102 			fregs = get_fpu_regs(child);
103 			if (test_tsk_thread_flag(child, TIF_32BIT_FPREGS)) {
104 				/*
105 				 * The odd registers are actually the high
106 				 * order bits of the values stored in the even
107 				 * registers.
108 				 */
109 				tmp = get_fpr32(&fregs[(addr & ~1) - FPR_BASE],
110 						addr & 1);
111 				break;
112 			}
113 			tmp = get_fpr64(&fregs[addr - FPR_BASE], 0);
114 			break;
115 		}
116 		case FPC_CSR:
117 			tmp = child->thread.fpu.fcr31;
118 			break;
119 		case FPC_EIR:
120 			/* implementation / version register */
121 			tmp = boot_cpu_data.fpu_id;
122 			break;
123 #endif /* CONFIG_MIPS_FP_SUPPORT */
124 		case PC:
125 			tmp = regs->cp0_epc;
126 			break;
127 		case CAUSE:
128 			tmp = regs->cp0_cause;
129 			break;
130 		case BADVADDR:
131 			tmp = regs->cp0_badvaddr;
132 			break;
133 		case MMHI:
134 			tmp = regs->hi;
135 			break;
136 		case MMLO:
137 			tmp = regs->lo;
138 			break;
139 		case DSP_BASE ... DSP_BASE + 5: {
140 			dspreg_t *dregs;
141 
142 			if (!cpu_has_dsp) {
143 				tmp = 0;
144 				ret = -EIO;
145 				goto out;
146 			}
147 			dregs = __get_dsp_regs(child);
148 			tmp = dregs[addr - DSP_BASE];
149 			break;
150 		}
151 		case DSP_CONTROL:
152 			if (!cpu_has_dsp) {
153 				tmp = 0;
154 				ret = -EIO;
155 				goto out;
156 			}
157 			tmp = child->thread.dsp.dspcontrol;
158 			break;
159 		default:
160 			tmp = 0;
161 			ret = -EIO;
162 			goto out;
163 		}
164 		ret = put_user(tmp, (unsigned __user *) (unsigned long) data);
165 		break;
166 	}
167 
168 	/*
169 	 * Write 4 bytes into the other process' storage
170 	 *  data is the 4 bytes that the user wants written
171 	 *  addr is a pointer in the user's storage that contains an
172 	 *	8 byte address in the other process where the 4 bytes
173 	 *	that is to be written
174 	 * (this is run in a 32-bit process looking at a 64-bit process)
175 	 * when I and D space are separate, these will need to be fixed.
176 	 */
177 	case PTRACE_POKETEXT_3264:
178 	case PTRACE_POKEDATA_3264: {
179 		u32 __user * addrOthers;
180 
181 		/* Get the addr in the other process that we want to write into */
182 		ret = -EIO;
183 		if (get_user(addrOthers, (u32 __user * __user *) (unsigned long) addr) != 0)
184 			break;
185 		ret = 0;
186 		if (ptrace_access_vm(child, (u64)addrOthers, &data,
187 					sizeof(data),
188 					FOLL_FORCE | FOLL_WRITE) == sizeof(data))
189 			break;
190 		ret = -EIO;
191 		break;
192 	}
193 
194 	case PTRACE_POKEUSR: {
195 		struct pt_regs *regs;
196 		ret = 0;
197 		regs = task_pt_regs(child);
198 
199 		switch (addr) {
200 		case 0 ... 31:
201 			regs->regs[addr] = data;
202 			/* System call number may have been changed */
203 			if (addr == 2)
204 				mips_syscall_update_nr(child, regs);
205 			else if (addr == 4 &&
206 				 mips_syscall_is_indirect(child, regs))
207 				mips_syscall_update_nr(child, regs);
208 			break;
209 #ifdef CONFIG_MIPS_FP_SUPPORT
210 		case FPR_BASE ... FPR_BASE + 31: {
211 			union fpureg *fregs = get_fpu_regs(child);
212 
213 			if (!tsk_used_math(child)) {
214 				/* FP not yet used  */
215 				memset(&child->thread.fpu, ~0,
216 				       sizeof(child->thread.fpu));
217 				child->thread.fpu.fcr31 = 0;
218 			}
219 			if (test_tsk_thread_flag(child, TIF_32BIT_FPREGS)) {
220 				/*
221 				 * The odd registers are actually the high
222 				 * order bits of the values stored in the even
223 				 * registers.
224 				 */
225 				set_fpr32(&fregs[(addr & ~1) - FPR_BASE],
226 					  addr & 1, data);
227 				break;
228 			}
229 			set_fpr64(&fregs[addr - FPR_BASE], 0, data);
230 			break;
231 		}
232 		case FPC_CSR:
233 			child->thread.fpu.fcr31 = data;
234 			break;
235 #endif /* CONFIG_MIPS_FP_SUPPORT */
236 		case PC:
237 			regs->cp0_epc = data;
238 			break;
239 		case MMHI:
240 			regs->hi = data;
241 			break;
242 		case MMLO:
243 			regs->lo = data;
244 			break;
245 		case DSP_BASE ... DSP_BASE + 5: {
246 			dspreg_t *dregs;
247 
248 			if (!cpu_has_dsp) {
249 				ret = -EIO;
250 				break;
251 			}
252 
253 			dregs = __get_dsp_regs(child);
254 			dregs[addr - DSP_BASE] = data;
255 			break;
256 		}
257 		case DSP_CONTROL:
258 			if (!cpu_has_dsp) {
259 				ret = -EIO;
260 				break;
261 			}
262 			child->thread.dsp.dspcontrol = data;
263 			break;
264 		default:
265 			/* The rest are not allowed. */
266 			ret = -EIO;
267 			break;
268 		}
269 		break;
270 		}
271 
272 	case PTRACE_GETREGS:
273 		ret = ptrace_getregs(child,
274 				(struct user_pt_regs __user *) (__u64) data);
275 		break;
276 
277 	case PTRACE_SETREGS:
278 		ret = ptrace_setregs(child,
279 				(struct user_pt_regs __user *) (__u64) data);
280 		break;
281 
282 #ifdef CONFIG_MIPS_FP_SUPPORT
283 	case PTRACE_GETFPREGS:
284 		ret = ptrace_getfpregs(child, (__u32 __user *) (__u64) data);
285 		break;
286 
287 	case PTRACE_SETFPREGS:
288 		ret = ptrace_setfpregs(child, (__u32 __user *) (__u64) data);
289 		break;
290 #endif
291 	case PTRACE_GET_THREAD_AREA:
292 		ret = put_user(task_thread_info(child)->tp_value,
293 				(unsigned int __user *) (unsigned long) data);
294 		break;
295 
296 	case PTRACE_GET_THREAD_AREA_3264:
297 		ret = put_user(task_thread_info(child)->tp_value,
298 				(unsigned long __user *) (unsigned long) data);
299 		break;
300 
301 	case PTRACE_GET_WATCH_REGS:
302 		ret = ptrace_get_watch_regs(child,
303 			(struct pt_watch_regs __user *) (unsigned long) addr);
304 		break;
305 
306 	case PTRACE_SET_WATCH_REGS:
307 		ret = ptrace_set_watch_regs(child,
308 			(struct pt_watch_regs __user *) (unsigned long) addr);
309 		break;
310 
311 	default:
312 		ret = compat_ptrace_request(child, request, addr, data);
313 		break;
314 	}
315 out:
316 	return ret;
317 }
318