xref: /openbmc/linux/arch/mips/kernel/ptrace32.c (revision 48c926cd)
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/pgtable.h>
34 #include <asm/page.h>
35 #include <asm/reg.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  */
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 		union fpureg *fregs;
85 		unsigned int tmp;
86 
87 		regs = task_pt_regs(child);
88 		ret = 0;  /* Default return value. */
89 
90 		switch (addr) {
91 		case 0 ... 31:
92 			tmp = regs->regs[addr];
93 			break;
94 		case FPR_BASE ... FPR_BASE + 31:
95 			if (!tsk_used_math(child)) {
96 				/* FP not yet used */
97 				tmp = -1;
98 				break;
99 			}
100 			fregs = get_fpu_regs(child);
101 			if (test_thread_flag(TIF_32BIT_FPREGS)) {
102 				/*
103 				 * The odd registers are actually the high
104 				 * order bits of the values stored in the even
105 				 * registers - unless we're using r2k_switch.S.
106 				 */
107 				tmp = get_fpr32(&fregs[(addr & ~1) - FPR_BASE],
108 						addr & 1);
109 				break;
110 			}
111 			tmp = get_fpr32(&fregs[addr - FPR_BASE], 0);
112 			break;
113 		case PC:
114 			tmp = regs->cp0_epc;
115 			break;
116 		case CAUSE:
117 			tmp = regs->cp0_cause;
118 			break;
119 		case BADVADDR:
120 			tmp = regs->cp0_badvaddr;
121 			break;
122 		case MMHI:
123 			tmp = regs->hi;
124 			break;
125 		case MMLO:
126 			tmp = regs->lo;
127 			break;
128 		case FPC_CSR:
129 			tmp = child->thread.fpu.fcr31;
130 			break;
131 		case FPC_EIR:
132 			/* implementation / version register */
133 			tmp = boot_cpu_data.fpu_id;
134 			break;
135 		case DSP_BASE ... DSP_BASE + 5: {
136 			dspreg_t *dregs;
137 
138 			if (!cpu_has_dsp) {
139 				tmp = 0;
140 				ret = -EIO;
141 				goto out;
142 			}
143 			dregs = __get_dsp_regs(child);
144 			tmp = (unsigned long) (dregs[addr - DSP_BASE]);
145 			break;
146 		}
147 		case DSP_CONTROL:
148 			if (!cpu_has_dsp) {
149 				tmp = 0;
150 				ret = -EIO;
151 				goto out;
152 			}
153 			tmp = child->thread.dsp.dspcontrol;
154 			break;
155 		default:
156 			tmp = 0;
157 			ret = -EIO;
158 			goto out;
159 		}
160 		ret = put_user(tmp, (unsigned __user *) (unsigned long) data);
161 		break;
162 	}
163 
164 	/*
165 	 * Write 4 bytes into the other process' storage
166 	 *  data is the 4 bytes that the user wants written
167 	 *  addr is a pointer in the user's storage that contains an
168 	 *	8 byte address in the other process where the 4 bytes
169 	 *	that is to be written
170 	 * (this is run in a 32-bit process looking at a 64-bit process)
171 	 * when I and D space are separate, these will need to be fixed.
172 	 */
173 	case PTRACE_POKETEXT_3264:
174 	case PTRACE_POKEDATA_3264: {
175 		u32 __user * addrOthers;
176 
177 		/* Get the addr in the other process that we want to write into */
178 		ret = -EIO;
179 		if (get_user(addrOthers, (u32 __user * __user *) (unsigned long) addr) != 0)
180 			break;
181 		ret = 0;
182 		if (ptrace_access_vm(child, (u64)addrOthers, &data,
183 					sizeof(data),
184 					FOLL_FORCE | FOLL_WRITE) == sizeof(data))
185 			break;
186 		ret = -EIO;
187 		break;
188 	}
189 
190 	case PTRACE_POKEUSR: {
191 		struct pt_regs *regs;
192 		ret = 0;
193 		regs = task_pt_regs(child);
194 
195 		switch (addr) {
196 		case 0 ... 31:
197 			regs->regs[addr] = data;
198 			break;
199 		case FPR_BASE ... FPR_BASE + 31: {
200 			union fpureg *fregs = get_fpu_regs(child);
201 
202 			if (!tsk_used_math(child)) {
203 				/* FP not yet used  */
204 				memset(&child->thread.fpu, ~0,
205 				       sizeof(child->thread.fpu));
206 				child->thread.fpu.fcr31 = 0;
207 			}
208 			if (test_thread_flag(TIF_32BIT_FPREGS)) {
209 				/*
210 				 * The odd registers are actually the high
211 				 * order bits of the values stored in the even
212 				 * registers - unless we're using r2k_switch.S.
213 				 */
214 				set_fpr32(&fregs[(addr & ~1) - FPR_BASE],
215 					  addr & 1, data);
216 				break;
217 			}
218 			set_fpr64(&fregs[addr - FPR_BASE], 0, data);
219 			break;
220 		}
221 		case PC:
222 			regs->cp0_epc = data;
223 			break;
224 		case MMHI:
225 			regs->hi = data;
226 			break;
227 		case MMLO:
228 			regs->lo = data;
229 			break;
230 		case FPC_CSR:
231 			child->thread.fpu.fcr31 = data;
232 			break;
233 		case DSP_BASE ... DSP_BASE + 5: {
234 			dspreg_t *dregs;
235 
236 			if (!cpu_has_dsp) {
237 				ret = -EIO;
238 				break;
239 			}
240 
241 			dregs = __get_dsp_regs(child);
242 			dregs[addr - DSP_BASE] = data;
243 			break;
244 		}
245 		case DSP_CONTROL:
246 			if (!cpu_has_dsp) {
247 				ret = -EIO;
248 				break;
249 			}
250 			child->thread.dsp.dspcontrol = data;
251 			break;
252 		default:
253 			/* The rest are not allowed. */
254 			ret = -EIO;
255 			break;
256 		}
257 		break;
258 		}
259 
260 	case PTRACE_GETREGS:
261 		ret = ptrace_getregs(child,
262 				(struct user_pt_regs __user *) (__u64) data);
263 		break;
264 
265 	case PTRACE_SETREGS:
266 		ret = ptrace_setregs(child,
267 				(struct user_pt_regs __user *) (__u64) data);
268 		break;
269 
270 	case PTRACE_GETFPREGS:
271 		ret = ptrace_getfpregs(child, (__u32 __user *) (__u64) data);
272 		break;
273 
274 	case PTRACE_SETFPREGS:
275 		ret = ptrace_setfpregs(child, (__u32 __user *) (__u64) data);
276 		break;
277 
278 	case PTRACE_GET_THREAD_AREA:
279 		ret = put_user(task_thread_info(child)->tp_value,
280 				(unsigned int __user *) (unsigned long) data);
281 		break;
282 
283 	case PTRACE_GET_THREAD_AREA_3264:
284 		ret = put_user(task_thread_info(child)->tp_value,
285 				(unsigned long __user *) (unsigned long) data);
286 		break;
287 
288 	case PTRACE_GET_WATCH_REGS:
289 		ret = ptrace_get_watch_regs(child,
290 			(struct pt_watch_regs __user *) (unsigned long) addr);
291 		break;
292 
293 	case PTRACE_SET_WATCH_REGS:
294 		ret = ptrace_set_watch_regs(child,
295 			(struct pt_watch_regs __user *) (unsigned long) addr);
296 		break;
297 
298 	default:
299 		ret = compat_ptrace_request(child, request, addr, data);
300 		break;
301 	}
302 out:
303 	return ret;
304 }
305