xref: /openbmc/linux/arch/mips/kernel/ptrace32.c (revision 930beb5a)
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 		fpureg_t *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 				if (addr & 1)
107 					tmp = fregs[(addr & ~1) - 32] >> 32;
108 				else
109 					tmp = fregs[addr - 32];
110 				break;
111 			}
112 			tmp = fregs[addr - FPR_BASE];
113 			break;
114 		case PC:
115 			tmp = regs->cp0_epc;
116 			break;
117 		case CAUSE:
118 			tmp = regs->cp0_cause;
119 			break;
120 		case BADVADDR:
121 			tmp = regs->cp0_badvaddr;
122 			break;
123 		case MMHI:
124 			tmp = regs->hi;
125 			break;
126 		case MMLO:
127 			tmp = regs->lo;
128 			break;
129 		case FPC_CSR:
130 			tmp = child->thread.fpu.fcr31;
131 			break;
132 		case FPC_EIR: { /* implementation / version register */
133 			unsigned int flags;
134 #ifdef CONFIG_MIPS_MT_SMTC
135 			unsigned int irqflags;
136 			unsigned int mtflags;
137 #endif /* CONFIG_MIPS_MT_SMTC */
138 
139 			preempt_disable();
140 			if (!cpu_has_fpu) {
141 				preempt_enable();
142 				tmp = 0;
143 				break;
144 			}
145 
146 #ifdef CONFIG_MIPS_MT_SMTC
147 			/* Read-modify-write of Status must be atomic */
148 			local_irq_save(irqflags);
149 			mtflags = dmt();
150 #endif /* CONFIG_MIPS_MT_SMTC */
151 
152 			if (cpu_has_mipsmt) {
153 				unsigned int vpflags = dvpe();
154 				flags = read_c0_status();
155 				__enable_fpu(FPU_AS_IS);
156 				__asm__ __volatile__("cfc1\t%0,$0": "=r" (tmp));
157 				write_c0_status(flags);
158 				evpe(vpflags);
159 			} else {
160 				flags = read_c0_status();
161 				__enable_fpu(FPU_AS_IS);
162 				__asm__ __volatile__("cfc1\t%0,$0": "=r" (tmp));
163 				write_c0_status(flags);
164 			}
165 #ifdef CONFIG_MIPS_MT_SMTC
166 			emt(mtflags);
167 			local_irq_restore(irqflags);
168 #endif /* CONFIG_MIPS_MT_SMTC */
169 			preempt_enable();
170 			break;
171 		}
172 		case DSP_BASE ... DSP_BASE + 5: {
173 			dspreg_t *dregs;
174 
175 			if (!cpu_has_dsp) {
176 				tmp = 0;
177 				ret = -EIO;
178 				goto out;
179 			}
180 			dregs = __get_dsp_regs(child);
181 			tmp = (unsigned long) (dregs[addr - DSP_BASE]);
182 			break;
183 		}
184 		case DSP_CONTROL:
185 			if (!cpu_has_dsp) {
186 				tmp = 0;
187 				ret = -EIO;
188 				goto out;
189 			}
190 			tmp = child->thread.dsp.dspcontrol;
191 			break;
192 		default:
193 			tmp = 0;
194 			ret = -EIO;
195 			goto out;
196 		}
197 		ret = put_user(tmp, (unsigned __user *) (unsigned long) data);
198 		break;
199 	}
200 
201 	/*
202 	 * Write 4 bytes into the other process' storage
203 	 *  data is the 4 bytes that the user wants written
204 	 *  addr is a pointer in the user's storage that contains an
205 	 *	8 byte address in the other process where the 4 bytes
206 	 *	that is to be written
207 	 * (this is run in a 32-bit process looking at a 64-bit process)
208 	 * when I and D space are separate, these will need to be fixed.
209 	 */
210 	case PTRACE_POKETEXT_3264:
211 	case PTRACE_POKEDATA_3264: {
212 		u32 __user * addrOthers;
213 
214 		/* Get the addr in the other process that we want to write into */
215 		ret = -EIO;
216 		if (get_user(addrOthers, (u32 __user * __user *) (unsigned long) addr) != 0)
217 			break;
218 		ret = 0;
219 		if (access_process_vm(child, (u64)addrOthers, &data,
220 					sizeof(data), 1) == sizeof(data))
221 			break;
222 		ret = -EIO;
223 		break;
224 	}
225 
226 	case PTRACE_POKEUSR: {
227 		struct pt_regs *regs;
228 		ret = 0;
229 		regs = task_pt_regs(child);
230 
231 		switch (addr) {
232 		case 0 ... 31:
233 			regs->regs[addr] = data;
234 			break;
235 		case FPR_BASE ... FPR_BASE + 31: {
236 			fpureg_t *fregs = get_fpu_regs(child);
237 
238 			if (!tsk_used_math(child)) {
239 				/* FP not yet used  */
240 				memset(&child->thread.fpu, ~0,
241 				       sizeof(child->thread.fpu));
242 				child->thread.fpu.fcr31 = 0;
243 			}
244 			if (test_thread_flag(TIF_32BIT_FPREGS)) {
245 				/*
246 				 * The odd registers are actually the high
247 				 * order bits of the values stored in the even
248 				 * registers - unless we're using r2k_switch.S.
249 				 */
250 				if (addr & 1) {
251 					fregs[(addr & ~1) - FPR_BASE] &=
252 						0xffffffff;
253 					fregs[(addr & ~1) - FPR_BASE] |=
254 						((u64)data) << 32;
255 				} else {
256 					fregs[addr - FPR_BASE] &= ~0xffffffffLL;
257 					fregs[addr - FPR_BASE] |= data;
258 				}
259 				break;
260 			}
261 			fregs[addr - FPR_BASE] = data;
262 			break;
263 		}
264 		case PC:
265 			regs->cp0_epc = data;
266 			break;
267 		case MMHI:
268 			regs->hi = data;
269 			break;
270 		case MMLO:
271 			regs->lo = data;
272 			break;
273 		case FPC_CSR:
274 			child->thread.fpu.fcr31 = data;
275 			break;
276 		case DSP_BASE ... DSP_BASE + 5: {
277 			dspreg_t *dregs;
278 
279 			if (!cpu_has_dsp) {
280 				ret = -EIO;
281 				break;
282 			}
283 
284 			dregs = __get_dsp_regs(child);
285 			dregs[addr - DSP_BASE] = data;
286 			break;
287 		}
288 		case DSP_CONTROL:
289 			if (!cpu_has_dsp) {
290 				ret = -EIO;
291 				break;
292 			}
293 			child->thread.dsp.dspcontrol = data;
294 			break;
295 		default:
296 			/* The rest are not allowed. */
297 			ret = -EIO;
298 			break;
299 		}
300 		break;
301 		}
302 
303 	case PTRACE_GETREGS:
304 		ret = ptrace_getregs(child, (__s64 __user *) (__u64) data);
305 		break;
306 
307 	case PTRACE_SETREGS:
308 		ret = ptrace_setregs(child, (__s64 __user *) (__u64) data);
309 		break;
310 
311 	case PTRACE_GETFPREGS:
312 		ret = ptrace_getfpregs(child, (__u32 __user *) (__u64) data);
313 		break;
314 
315 	case PTRACE_SETFPREGS:
316 		ret = ptrace_setfpregs(child, (__u32 __user *) (__u64) data);
317 		break;
318 
319 	case PTRACE_GET_THREAD_AREA:
320 		ret = put_user(task_thread_info(child)->tp_value,
321 				(unsigned int __user *) (unsigned long) data);
322 		break;
323 
324 	case PTRACE_GET_THREAD_AREA_3264:
325 		ret = put_user(task_thread_info(child)->tp_value,
326 				(unsigned long __user *) (unsigned long) data);
327 		break;
328 
329 	case PTRACE_GET_WATCH_REGS:
330 		ret = ptrace_get_watch_regs(child,
331 			(struct pt_watch_regs __user *) (unsigned long) addr);
332 		break;
333 
334 	case PTRACE_SET_WATCH_REGS:
335 		ret = ptrace_set_watch_regs(child,
336 			(struct pt_watch_regs __user *) (unsigned long) addr);
337 		break;
338 
339 	default:
340 		ret = compat_ptrace_request(child, request, addr, data);
341 		break;
342 	}
343 out:
344 	return ret;
345 }
346