xref: /openbmc/linux/arch/mips/kernel/ptrace32.c (revision ae3473231e77a3f1909d48cd144cebe5e1d049b3)
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/mm.h>
22 #include <linux/errno.h>
23 #include <linux/ptrace.h>
24 #include <linux/smp.h>
25 #include <linux/security.h>
26 
27 #include <asm/cpu.h>
28 #include <asm/dsp.h>
29 #include <asm/fpu.h>
30 #include <asm/mipsregs.h>
31 #include <asm/mipsmtregs.h>
32 #include <asm/pgtable.h>
33 #include <asm/page.h>
34 #include <asm/reg.h>
35 #include <linux/uaccess.h>
36 #include <asm/bootinfo.h>
37 
38 /*
39  * Tracing a 32-bit process with a 64-bit strace and vice versa will not
40  * work.  I don't know how to fix this.
41  */
42 long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
43 			compat_ulong_t caddr, compat_ulong_t cdata)
44 {
45 	int addr = caddr;
46 	int data = cdata;
47 	int ret;
48 
49 	switch (request) {
50 
51 	/*
52 	 * Read 4 bytes of the other process' storage
53 	 *  data is a pointer specifying where the user wants the
54 	 *	4 bytes copied into
55 	 *  addr is a pointer in the user's storage that contains an 8 byte
56 	 *	address in the other process of the 4 bytes that is to be read
57 	 * (this is run in a 32-bit process looking at a 64-bit process)
58 	 * when I and D space are separate, these will need to be fixed.
59 	 */
60 	case PTRACE_PEEKTEXT_3264:
61 	case PTRACE_PEEKDATA_3264: {
62 		u32 tmp;
63 		int copied;
64 		u32 __user * addrOthers;
65 
66 		ret = -EIO;
67 
68 		/* Get the addr in the other process that we want to read */
69 		if (get_user(addrOthers, (u32 __user * __user *) (unsigned long) addr) != 0)
70 			break;
71 
72 		copied = ptrace_access_vm(child, (u64)addrOthers, &tmp,
73 				sizeof(tmp), FOLL_FORCE);
74 		if (copied != sizeof(tmp))
75 			break;
76 		ret = put_user(tmp, (u32 __user *) (unsigned long) data);
77 		break;
78 	}
79 
80 	/* Read the word at location addr in the USER area. */
81 	case PTRACE_PEEKUSR: {
82 		struct pt_regs *regs;
83 		union fpureg *fregs;
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 		case FPR_BASE ... FPR_BASE + 31:
94 			if (!tsk_used_math(child)) {
95 				/* FP not yet used */
96 				tmp = -1;
97 				break;
98 			}
99 			fregs = get_fpu_regs(child);
100 			if (test_thread_flag(TIF_32BIT_FPREGS)) {
101 				/*
102 				 * The odd registers are actually the high
103 				 * order bits of the values stored in the even
104 				 * registers - unless we're using r2k_switch.S.
105 				 */
106 				tmp = get_fpr32(&fregs[(addr & ~1) - FPR_BASE],
107 						addr & 1);
108 				break;
109 			}
110 			tmp = get_fpr32(&fregs[addr - FPR_BASE], 0);
111 			break;
112 		case PC:
113 			tmp = regs->cp0_epc;
114 			break;
115 		case CAUSE:
116 			tmp = regs->cp0_cause;
117 			break;
118 		case BADVADDR:
119 			tmp = regs->cp0_badvaddr;
120 			break;
121 		case MMHI:
122 			tmp = regs->hi;
123 			break;
124 		case MMLO:
125 			tmp = regs->lo;
126 			break;
127 		case FPC_CSR:
128 			tmp = child->thread.fpu.fcr31;
129 			break;
130 		case FPC_EIR:
131 			/* implementation / version register */
132 			tmp = boot_cpu_data.fpu_id;
133 			break;
134 		case DSP_BASE ... DSP_BASE + 5: {
135 			dspreg_t *dregs;
136 
137 			if (!cpu_has_dsp) {
138 				tmp = 0;
139 				ret = -EIO;
140 				goto out;
141 			}
142 			dregs = __get_dsp_regs(child);
143 			tmp = (unsigned long) (dregs[addr - DSP_BASE]);
144 			break;
145 		}
146 		case DSP_CONTROL:
147 			if (!cpu_has_dsp) {
148 				tmp = 0;
149 				ret = -EIO;
150 				goto out;
151 			}
152 			tmp = child->thread.dsp.dspcontrol;
153 			break;
154 		default:
155 			tmp = 0;
156 			ret = -EIO;
157 			goto out;
158 		}
159 		ret = put_user(tmp, (unsigned __user *) (unsigned long) data);
160 		break;
161 	}
162 
163 	/*
164 	 * Write 4 bytes into the other process' storage
165 	 *  data is the 4 bytes that the user wants written
166 	 *  addr is a pointer in the user's storage that contains an
167 	 *	8 byte address in the other process where the 4 bytes
168 	 *	that is to be written
169 	 * (this is run in a 32-bit process looking at a 64-bit process)
170 	 * when I and D space are separate, these will need to be fixed.
171 	 */
172 	case PTRACE_POKETEXT_3264:
173 	case PTRACE_POKEDATA_3264: {
174 		u32 __user * addrOthers;
175 
176 		/* Get the addr in the other process that we want to write into */
177 		ret = -EIO;
178 		if (get_user(addrOthers, (u32 __user * __user *) (unsigned long) addr) != 0)
179 			break;
180 		ret = 0;
181 		if (ptrace_access_vm(child, (u64)addrOthers, &data,
182 					sizeof(data),
183 					FOLL_FORCE | FOLL_WRITE) == sizeof(data))
184 			break;
185 		ret = -EIO;
186 		break;
187 	}
188 
189 	case PTRACE_POKEUSR: {
190 		struct pt_regs *regs;
191 		ret = 0;
192 		regs = task_pt_regs(child);
193 
194 		switch (addr) {
195 		case 0 ... 31:
196 			regs->regs[addr] = data;
197 			break;
198 		case FPR_BASE ... FPR_BASE + 31: {
199 			union fpureg *fregs = get_fpu_regs(child);
200 
201 			if (!tsk_used_math(child)) {
202 				/* FP not yet used  */
203 				memset(&child->thread.fpu, ~0,
204 				       sizeof(child->thread.fpu));
205 				child->thread.fpu.fcr31 = 0;
206 			}
207 			if (test_thread_flag(TIF_32BIT_FPREGS)) {
208 				/*
209 				 * The odd registers are actually the high
210 				 * order bits of the values stored in the even
211 				 * registers - unless we're using r2k_switch.S.
212 				 */
213 				set_fpr32(&fregs[(addr & ~1) - FPR_BASE],
214 					  addr & 1, data);
215 				break;
216 			}
217 			set_fpr64(&fregs[addr - FPR_BASE], 0, data);
218 			break;
219 		}
220 		case PC:
221 			regs->cp0_epc = data;
222 			break;
223 		case MMHI:
224 			regs->hi = data;
225 			break;
226 		case MMLO:
227 			regs->lo = data;
228 			break;
229 		case FPC_CSR:
230 			child->thread.fpu.fcr31 = data;
231 			break;
232 		case DSP_BASE ... DSP_BASE + 5: {
233 			dspreg_t *dregs;
234 
235 			if (!cpu_has_dsp) {
236 				ret = -EIO;
237 				break;
238 			}
239 
240 			dregs = __get_dsp_regs(child);
241 			dregs[addr - DSP_BASE] = data;
242 			break;
243 		}
244 		case DSP_CONTROL:
245 			if (!cpu_has_dsp) {
246 				ret = -EIO;
247 				break;
248 			}
249 			child->thread.dsp.dspcontrol = data;
250 			break;
251 		default:
252 			/* The rest are not allowed. */
253 			ret = -EIO;
254 			break;
255 		}
256 		break;
257 		}
258 
259 	case PTRACE_GETREGS:
260 		ret = ptrace_getregs(child,
261 				(struct user_pt_regs __user *) (__u64) data);
262 		break;
263 
264 	case PTRACE_SETREGS:
265 		ret = ptrace_setregs(child,
266 				(struct user_pt_regs __user *) (__u64) data);
267 		break;
268 
269 	case PTRACE_GETFPREGS:
270 		ret = ptrace_getfpregs(child, (__u32 __user *) (__u64) data);
271 		break;
272 
273 	case PTRACE_SETFPREGS:
274 		ret = ptrace_setfpregs(child, (__u32 __user *) (__u64) data);
275 		break;
276 
277 	case PTRACE_GET_THREAD_AREA:
278 		ret = put_user(task_thread_info(child)->tp_value,
279 				(unsigned int __user *) (unsigned long) data);
280 		break;
281 
282 	case PTRACE_GET_THREAD_AREA_3264:
283 		ret = put_user(task_thread_info(child)->tp_value,
284 				(unsigned long __user *) (unsigned long) data);
285 		break;
286 
287 	case PTRACE_GET_WATCH_REGS:
288 		ret = ptrace_get_watch_regs(child,
289 			(struct pt_watch_regs __user *) (unsigned long) addr);
290 		break;
291 
292 	case PTRACE_SET_WATCH_REGS:
293 		ret = ptrace_set_watch_regs(child,
294 			(struct pt_watch_regs __user *) (unsigned long) addr);
295 		break;
296 
297 	default:
298 		ret = compat_ptrace_request(child, request, addr, data);
299 		break;
300 	}
301 out:
302 	return ret;
303 }
304