xref: /linux/arch/mips/kernel/ptrace32.c (revision b7019ac550eb3916f34d79db583e9b7ea2524afa)
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 <asm/syscall.h>
37 #include <linux/uaccess.h>
38 #include <asm/bootinfo.h>
39 
40 /*
41  * Tracing a 32-bit process with a 64-bit strace and vice versa will not
42  * work.  I don't know how to fix this.
43  */
44 long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
45 			compat_ulong_t caddr, compat_ulong_t cdata)
46 {
47 	int addr = caddr;
48 	int data = cdata;
49 	int ret;
50 
51 	switch (request) {
52 
53 	/*
54 	 * Read 4 bytes of the other process' storage
55 	 *  data is a pointer specifying where the user wants the
56 	 *	4 bytes copied into
57 	 *  addr is a pointer in the user's storage that contains an 8 byte
58 	 *	address in the other process of the 4 bytes that is to be read
59 	 * (this is run in a 32-bit process looking at a 64-bit process)
60 	 * when I and D space are separate, these will need to be fixed.
61 	 */
62 	case PTRACE_PEEKTEXT_3264:
63 	case PTRACE_PEEKDATA_3264: {
64 		u32 tmp;
65 		int copied;
66 		u32 __user * addrOthers;
67 
68 		ret = -EIO;
69 
70 		/* Get the addr in the other process that we want to read */
71 		if (get_user(addrOthers, (u32 __user * __user *) (unsigned long) addr) != 0)
72 			break;
73 
74 		copied = ptrace_access_vm(child, (u64)addrOthers, &tmp,
75 				sizeof(tmp), FOLL_FORCE);
76 		if (copied != sizeof(tmp))
77 			break;
78 		ret = put_user(tmp, (u32 __user *) (unsigned long) data);
79 		break;
80 	}
81 
82 	/* Read the word at location addr in the USER area. */
83 	case PTRACE_PEEKUSR: {
84 		struct pt_regs *regs;
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 #ifdef CONFIG_MIPS_FP_SUPPORT
95 		case FPR_BASE ... FPR_BASE + 31: {
96 			union fpureg *fregs;
97 
98 			if (!tsk_used_math(child)) {
99 				/* FP not yet used */
100 				tmp = -1;
101 				break;
102 			}
103 			fregs = get_fpu_regs(child);
104 			if (test_tsk_thread_flag(child, TIF_32BIT_FPREGS)) {
105 				/*
106 				 * The odd registers are actually the high
107 				 * order bits of the values stored in the even
108 				 * registers.
109 				 */
110 				tmp = get_fpr32(&fregs[(addr & ~1) - FPR_BASE],
111 						addr & 1);
112 				break;
113 			}
114 			tmp = get_fpr64(&fregs[addr - FPR_BASE], 0);
115 			break;
116 		}
117 		case FPC_CSR:
118 			tmp = child->thread.fpu.fcr31;
119 			break;
120 		case FPC_EIR:
121 			/* implementation / version register */
122 			tmp = boot_cpu_data.fpu_id;
123 			break;
124 #endif /* CONFIG_MIPS_FP_SUPPORT */
125 		case PC:
126 			tmp = regs->cp0_epc;
127 			break;
128 		case CAUSE:
129 			tmp = regs->cp0_cause;
130 			break;
131 		case BADVADDR:
132 			tmp = regs->cp0_badvaddr;
133 			break;
134 		case MMHI:
135 			tmp = regs->hi;
136 			break;
137 		case MMLO:
138 			tmp = regs->lo;
139 			break;
140 		case DSP_BASE ... DSP_BASE + 5: {
141 			dspreg_t *dregs;
142 
143 			if (!cpu_has_dsp) {
144 				tmp = 0;
145 				ret = -EIO;
146 				goto out;
147 			}
148 			dregs = __get_dsp_regs(child);
149 			tmp = dregs[addr - DSP_BASE];
150 			break;
151 		}
152 		case DSP_CONTROL:
153 			if (!cpu_has_dsp) {
154 				tmp = 0;
155 				ret = -EIO;
156 				goto out;
157 			}
158 			tmp = child->thread.dsp.dspcontrol;
159 			break;
160 		default:
161 			tmp = 0;
162 			ret = -EIO;
163 			goto out;
164 		}
165 		ret = put_user(tmp, (unsigned __user *) (unsigned long) data);
166 		break;
167 	}
168 
169 	/*
170 	 * Write 4 bytes into the other process' storage
171 	 *  data is the 4 bytes that the user wants written
172 	 *  addr is a pointer in the user's storage that contains an
173 	 *	8 byte address in the other process where the 4 bytes
174 	 *	that is to be written
175 	 * (this is run in a 32-bit process looking at a 64-bit process)
176 	 * when I and D space are separate, these will need to be fixed.
177 	 */
178 	case PTRACE_POKETEXT_3264:
179 	case PTRACE_POKEDATA_3264: {
180 		u32 __user * addrOthers;
181 
182 		/* Get the addr in the other process that we want to write into */
183 		ret = -EIO;
184 		if (get_user(addrOthers, (u32 __user * __user *) (unsigned long) addr) != 0)
185 			break;
186 		ret = 0;
187 		if (ptrace_access_vm(child, (u64)addrOthers, &data,
188 					sizeof(data),
189 					FOLL_FORCE | FOLL_WRITE) == sizeof(data))
190 			break;
191 		ret = -EIO;
192 		break;
193 	}
194 
195 	case PTRACE_POKEUSR: {
196 		struct pt_regs *regs;
197 		ret = 0;
198 		regs = task_pt_regs(child);
199 
200 		switch (addr) {
201 		case 0 ... 31:
202 			regs->regs[addr] = data;
203 			/* System call number may have been changed */
204 			if (addr == 2)
205 				mips_syscall_update_nr(child, regs);
206 			else if (addr == 4 &&
207 				 mips_syscall_is_indirect(child, regs))
208 				mips_syscall_update_nr(child, regs);
209 			break;
210 #ifdef CONFIG_MIPS_FP_SUPPORT
211 		case FPR_BASE ... FPR_BASE + 31: {
212 			union fpureg *fregs = get_fpu_regs(child);
213 
214 			if (!tsk_used_math(child)) {
215 				/* FP not yet used  */
216 				memset(&child->thread.fpu, ~0,
217 				       sizeof(child->thread.fpu));
218 				child->thread.fpu.fcr31 = 0;
219 			}
220 			if (test_tsk_thread_flag(child, TIF_32BIT_FPREGS)) {
221 				/*
222 				 * The odd registers are actually the high
223 				 * order bits of the values stored in the even
224 				 * registers.
225 				 */
226 				set_fpr32(&fregs[(addr & ~1) - FPR_BASE],
227 					  addr & 1, data);
228 				break;
229 			}
230 			set_fpr64(&fregs[addr - FPR_BASE], 0, data);
231 			break;
232 		}
233 		case FPC_CSR:
234 			child->thread.fpu.fcr31 = data;
235 			break;
236 #endif /* CONFIG_MIPS_FP_SUPPORT */
237 		case PC:
238 			regs->cp0_epc = data;
239 			break;
240 		case MMHI:
241 			regs->hi = data;
242 			break;
243 		case MMLO:
244 			regs->lo = data;
245 			break;
246 		case DSP_BASE ... DSP_BASE + 5: {
247 			dspreg_t *dregs;
248 
249 			if (!cpu_has_dsp) {
250 				ret = -EIO;
251 				break;
252 			}
253 
254 			dregs = __get_dsp_regs(child);
255 			dregs[addr - DSP_BASE] = data;
256 			break;
257 		}
258 		case DSP_CONTROL:
259 			if (!cpu_has_dsp) {
260 				ret = -EIO;
261 				break;
262 			}
263 			child->thread.dsp.dspcontrol = data;
264 			break;
265 		default:
266 			/* The rest are not allowed. */
267 			ret = -EIO;
268 			break;
269 		}
270 		break;
271 		}
272 
273 	case PTRACE_GETREGS:
274 		ret = ptrace_getregs(child,
275 				(struct user_pt_regs __user *) (__u64) data);
276 		break;
277 
278 	case PTRACE_SETREGS:
279 		ret = ptrace_setregs(child,
280 				(struct user_pt_regs __user *) (__u64) data);
281 		break;
282 
283 #ifdef CONFIG_MIPS_FP_SUPPORT
284 	case PTRACE_GETFPREGS:
285 		ret = ptrace_getfpregs(child, (__u32 __user *) (__u64) data);
286 		break;
287 
288 	case PTRACE_SETFPREGS:
289 		ret = ptrace_setfpregs(child, (__u32 __user *) (__u64) data);
290 		break;
291 #endif
292 	case PTRACE_GET_THREAD_AREA:
293 		ret = put_user(task_thread_info(child)->tp_value,
294 				(unsigned int __user *) (unsigned long) data);
295 		break;
296 
297 	case PTRACE_GET_THREAD_AREA_3264:
298 		ret = put_user(task_thread_info(child)->tp_value,
299 				(unsigned long __user *) (unsigned long) data);
300 		break;
301 
302 	case PTRACE_GET_WATCH_REGS:
303 		ret = ptrace_get_watch_regs(child,
304 			(struct pt_watch_regs __user *) (unsigned long) addr);
305 		break;
306 
307 	case PTRACE_SET_WATCH_REGS:
308 		ret = ptrace_set_watch_regs(child,
309 			(struct pt_watch_regs __user *) (unsigned long) addr);
310 		break;
311 
312 	default:
313 		ret = compat_ptrace_request(child, request, addr, data);
314 		break;
315 	}
316 out:
317 	return ret;
318 }
319