xref: /linux/arch/mips/kernel/ptrace32.c (revision c4ee0af3fa0dc65f690fc908f02b8355f9576ea0)
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/user.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/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 = access_process_vm(child, (u64)addrOthers, &tmp,
73 				sizeof(tmp), 0);
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 		unsigned int tmp;
84 
85 		regs = task_pt_regs(child);
86 		ret = 0;  /* Default return value. */
87 
88 		switch (addr) {
89 		case 0 ... 31:
90 			tmp = regs->regs[addr];
91 			break;
92 		case FPR_BASE ... FPR_BASE + 31:
93 			if (tsk_used_math(child)) {
94 				fpureg_t *fregs = get_fpu_regs(child);
95 
96 				/*
97 				 * The odd registers are actually the high
98 				 * order bits of the values stored in the even
99 				 * registers - unless we're using r2k_switch.S.
100 				 */
101 				if (addr & 1)
102 					tmp = (unsigned long) (fregs[((addr & ~1) - 32)] >> 32);
103 				else
104 					tmp = (unsigned long) (fregs[(addr - 32)] & 0xffffffff);
105 			} else {
106 				tmp = -1;	/* FP not yet used  */
107 			}
108 			break;
109 		case PC:
110 			tmp = regs->cp0_epc;
111 			break;
112 		case CAUSE:
113 			tmp = regs->cp0_cause;
114 			break;
115 		case BADVADDR:
116 			tmp = regs->cp0_badvaddr;
117 			break;
118 		case MMHI:
119 			tmp = regs->hi;
120 			break;
121 		case MMLO:
122 			tmp = regs->lo;
123 			break;
124 		case FPC_CSR:
125 			tmp = child->thread.fpu.fcr31;
126 			break;
127 		case FPC_EIR: { /* implementation / version register */
128 			unsigned int flags;
129 #ifdef CONFIG_MIPS_MT_SMTC
130 			unsigned int irqflags;
131 			unsigned int mtflags;
132 #endif /* CONFIG_MIPS_MT_SMTC */
133 
134 			preempt_disable();
135 			if (!cpu_has_fpu) {
136 				preempt_enable();
137 				tmp = 0;
138 				break;
139 			}
140 
141 #ifdef CONFIG_MIPS_MT_SMTC
142 			/* Read-modify-write of Status must be atomic */
143 			local_irq_save(irqflags);
144 			mtflags = dmt();
145 #endif /* CONFIG_MIPS_MT_SMTC */
146 
147 			if (cpu_has_mipsmt) {
148 				unsigned int vpflags = dvpe();
149 				flags = read_c0_status();
150 				__enable_fpu();
151 				__asm__ __volatile__("cfc1\t%0,$0": "=r" (tmp));
152 				write_c0_status(flags);
153 				evpe(vpflags);
154 			} else {
155 				flags = read_c0_status();
156 				__enable_fpu();
157 				__asm__ __volatile__("cfc1\t%0,$0": "=r" (tmp));
158 				write_c0_status(flags);
159 			}
160 #ifdef CONFIG_MIPS_MT_SMTC
161 			emt(mtflags);
162 			local_irq_restore(irqflags);
163 #endif /* CONFIG_MIPS_MT_SMTC */
164 			preempt_enable();
165 			break;
166 		}
167 		case DSP_BASE ... DSP_BASE + 5: {
168 			dspreg_t *dregs;
169 
170 			if (!cpu_has_dsp) {
171 				tmp = 0;
172 				ret = -EIO;
173 				goto out;
174 			}
175 			dregs = __get_dsp_regs(child);
176 			tmp = (unsigned long) (dregs[addr - DSP_BASE]);
177 			break;
178 		}
179 		case DSP_CONTROL:
180 			if (!cpu_has_dsp) {
181 				tmp = 0;
182 				ret = -EIO;
183 				goto out;
184 			}
185 			tmp = child->thread.dsp.dspcontrol;
186 			break;
187 		default:
188 			tmp = 0;
189 			ret = -EIO;
190 			goto out;
191 		}
192 		ret = put_user(tmp, (unsigned __user *) (unsigned long) data);
193 		break;
194 	}
195 
196 	/*
197 	 * Write 4 bytes into the other process' storage
198 	 *  data is the 4 bytes that the user wants written
199 	 *  addr is a pointer in the user's storage that contains an
200 	 *	8 byte address in the other process where the 4 bytes
201 	 *	that is to be written
202 	 * (this is run in a 32-bit process looking at a 64-bit process)
203 	 * when I and D space are separate, these will need to be fixed.
204 	 */
205 	case PTRACE_POKETEXT_3264:
206 	case PTRACE_POKEDATA_3264: {
207 		u32 __user * addrOthers;
208 
209 		/* Get the addr in the other process that we want to write into */
210 		ret = -EIO;
211 		if (get_user(addrOthers, (u32 __user * __user *) (unsigned long) addr) != 0)
212 			break;
213 		ret = 0;
214 		if (access_process_vm(child, (u64)addrOthers, &data,
215 					sizeof(data), 1) == sizeof(data))
216 			break;
217 		ret = -EIO;
218 		break;
219 	}
220 
221 	case PTRACE_POKEUSR: {
222 		struct pt_regs *regs;
223 		ret = 0;
224 		regs = task_pt_regs(child);
225 
226 		switch (addr) {
227 		case 0 ... 31:
228 			regs->regs[addr] = data;
229 			break;
230 		case FPR_BASE ... FPR_BASE + 31: {
231 			fpureg_t *fregs = get_fpu_regs(child);
232 
233 			if (!tsk_used_math(child)) {
234 				/* FP not yet used  */
235 				memset(&child->thread.fpu, ~0,
236 				       sizeof(child->thread.fpu));
237 				child->thread.fpu.fcr31 = 0;
238 			}
239 			/*
240 			 * The odd registers are actually the high order bits
241 			 * of the values stored in the even registers - unless
242 			 * we're using r2k_switch.S.
243 			 */
244 			if (addr & 1) {
245 				fregs[(addr & ~1) - FPR_BASE] &= 0xffffffff;
246 				fregs[(addr & ~1) - FPR_BASE] |= ((unsigned long long) data) << 32;
247 			} else {
248 				fregs[addr - FPR_BASE] &= ~0xffffffffLL;
249 				/* Must cast, lest sign extension fill upper
250 				   bits!  */
251 				fregs[addr - FPR_BASE] |= (unsigned int)data;
252 			}
253 			break;
254 		}
255 		case PC:
256 			regs->cp0_epc = data;
257 			break;
258 		case MMHI:
259 			regs->hi = data;
260 			break;
261 		case MMLO:
262 			regs->lo = data;
263 			break;
264 		case FPC_CSR:
265 			child->thread.fpu.fcr31 = data;
266 			break;
267 		case DSP_BASE ... DSP_BASE + 5: {
268 			dspreg_t *dregs;
269 
270 			if (!cpu_has_dsp) {
271 				ret = -EIO;
272 				break;
273 			}
274 
275 			dregs = __get_dsp_regs(child);
276 			dregs[addr - DSP_BASE] = data;
277 			break;
278 		}
279 		case DSP_CONTROL:
280 			if (!cpu_has_dsp) {
281 				ret = -EIO;
282 				break;
283 			}
284 			child->thread.dsp.dspcontrol = data;
285 			break;
286 		default:
287 			/* The rest are not allowed. */
288 			ret = -EIO;
289 			break;
290 		}
291 		break;
292 		}
293 
294 	case PTRACE_GETREGS:
295 		ret = ptrace_getregs(child, (__s64 __user *) (__u64) data);
296 		break;
297 
298 	case PTRACE_SETREGS:
299 		ret = ptrace_setregs(child, (__s64 __user *) (__u64) data);
300 		break;
301 
302 	case PTRACE_GETFPREGS:
303 		ret = ptrace_getfpregs(child, (__u32 __user *) (__u64) data);
304 		break;
305 
306 	case PTRACE_SETFPREGS:
307 		ret = ptrace_setfpregs(child, (__u32 __user *) (__u64) data);
308 		break;
309 
310 	case PTRACE_GET_THREAD_AREA:
311 		ret = put_user(task_thread_info(child)->tp_value,
312 				(unsigned int __user *) (unsigned long) data);
313 		break;
314 
315 	case PTRACE_GET_THREAD_AREA_3264:
316 		ret = put_user(task_thread_info(child)->tp_value,
317 				(unsigned long __user *) (unsigned long) data);
318 		break;
319 
320 	case PTRACE_GET_WATCH_REGS:
321 		ret = ptrace_get_watch_regs(child,
322 			(struct pt_watch_regs __user *) (unsigned long) addr);
323 		break;
324 
325 	case PTRACE_SET_WATCH_REGS:
326 		ret = ptrace_set_watch_regs(child,
327 			(struct pt_watch_regs __user *) (unsigned long) addr);
328 		break;
329 
330 	default:
331 		ret = compat_ptrace_request(child, request, addr, data);
332 		break;
333 	}
334 out:
335 	return ret;
336 }
337