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1 /*
2  * ptrace for 32-bit processes running on a 64-bit kernel.
3  *
4  *  PowerPC version
5  *    Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
6  *
7  *  Derived from "arch/m68k/kernel/ptrace.c"
8  *  Copyright (C) 1994 by Hamish Macdonald
9  *  Taken from linux/kernel/ptrace.c and modified for M680x0.
10  *  linux/kernel/ptrace.c is by Ross Biro 1/23/92, edited by Linus Torvalds
11  *
12  * Modified by Cort Dougan (cort@hq.fsmlabs.com)
13  * and Paul Mackerras (paulus@samba.org).
14  *
15  * This file is subject to the terms and conditions of the GNU General
16  * Public License.  See the file COPYING in the main directory of
17  * this archive for more details.
18  */
19 
20 #include <linux/kernel.h>
21 #include <linux/sched.h>
22 #include <linux/mm.h>
23 #include <linux/smp.h>
24 #include <linux/smp_lock.h>
25 #include <linux/errno.h>
26 #include <linux/ptrace.h>
27 #include <linux/regset.h>
28 #include <linux/user.h>
29 #include <linux/security.h>
30 #include <linux/signal.h>
31 #include <linux/compat.h>
32 
33 #include <asm/uaccess.h>
34 #include <asm/page.h>
35 #include <asm/pgtable.h>
36 #include <asm/system.h>
37 
38 /*
39  * does not yet catch signals sent when the child dies.
40  * in exit.c or in signal.c.
41  */
42 
43 /*
44  * Here are the old "legacy" powerpc specific getregs/setregs ptrace calls,
45  * we mark them as obsolete now, they will be removed in a future version
46  */
compat_ptrace_old(struct task_struct * child,long request,long addr,long data)47 static long compat_ptrace_old(struct task_struct *child, long request,
48 			      long addr, long data)
49 {
50 	switch (request) {
51 	case PPC_PTRACE_GETREGS:	/* Get GPRs 0 - 31. */
52 		return copy_regset_to_user(child,
53 					   task_user_regset_view(current), 0,
54 					   0, 32 * sizeof(compat_long_t),
55 					   compat_ptr(data));
56 
57 	case PPC_PTRACE_SETREGS:	/* Set GPRs 0 - 31. */
58 		return copy_regset_from_user(child,
59 					     task_user_regset_view(current), 0,
60 					     0, 32 * sizeof(compat_long_t),
61 					     compat_ptr(data));
62 	}
63 
64 	return -EPERM;
65 }
66 
67 /* Macros to workout the correct index for the FPR in the thread struct */
68 #define FPRNUMBER(i) (((i) - PT_FPR0) >> 1)
69 #define FPRHALF(i) (((i) - PT_FPR0) & 1)
70 #define FPRINDEX(i) TS_FPRWIDTH * FPRNUMBER(i) + FPRHALF(i)
71 
compat_arch_ptrace(struct task_struct * child,compat_long_t request,compat_ulong_t caddr,compat_ulong_t cdata)72 long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
73 			compat_ulong_t caddr, compat_ulong_t cdata)
74 {
75 	unsigned long addr = caddr;
76 	unsigned long data = cdata;
77 	int ret;
78 
79 	switch (request) {
80 	/*
81 	 * Read 4 bytes of the other process' storage
82 	 *  data is a pointer specifying where the user wants the
83 	 *	4 bytes copied into
84 	 *  addr is a pointer in the user's storage that contains an 8 byte
85 	 *	address in the other process of the 4 bytes that is to be read
86 	 * (this is run in a 32-bit process looking at a 64-bit process)
87 	 * when I and D space are separate, these will need to be fixed.
88 	 */
89 	case PPC_PTRACE_PEEKTEXT_3264:
90 	case PPC_PTRACE_PEEKDATA_3264: {
91 		u32 tmp;
92 		int copied;
93 		u32 __user * addrOthers;
94 
95 		ret = -EIO;
96 
97 		/* Get the addr in the other process that we want to read */
98 		if (get_user(addrOthers, (u32 __user * __user *)addr) != 0)
99 			break;
100 
101 		copied = access_process_vm(child, (u64)addrOthers, &tmp,
102 				sizeof(tmp), 0);
103 		if (copied != sizeof(tmp))
104 			break;
105 		ret = put_user(tmp, (u32 __user *)data);
106 		break;
107 	}
108 
109 	/* Read a register (specified by ADDR) out of the "user area" */
110 	case PTRACE_PEEKUSR: {
111 		int index;
112 		unsigned long tmp;
113 
114 		ret = -EIO;
115 		/* convert to index and check */
116 		index = (unsigned long) addr >> 2;
117 		if ((addr & 3) || (index > PT_FPSCR32))
118 			break;
119 
120 		CHECK_FULL_REGS(child->thread.regs);
121 		if (index < PT_FPR0) {
122 			tmp = ptrace_get_reg(child, index);
123 		} else {
124 			flush_fp_to_thread(child);
125 			/*
126 			 * the user space code considers the floating point
127 			 * to be an array of unsigned int (32 bits) - the
128 			 * index passed in is based on this assumption.
129 			 */
130 			tmp = ((unsigned int *)child->thread.fpr)
131 				[FPRINDEX(index)];
132 		}
133 		ret = put_user((unsigned int)tmp, (u32 __user *)data);
134 		break;
135 	}
136 
137 	/*
138 	 * Read 4 bytes out of the other process' pt_regs area
139 	 *  data is a pointer specifying where the user wants the
140 	 *	4 bytes copied into
141 	 *  addr is the offset into the other process' pt_regs structure
142 	 *	that is to be read
143 	 * (this is run in a 32-bit process looking at a 64-bit process)
144 	 */
145 	case PPC_PTRACE_PEEKUSR_3264: {
146 		u32 index;
147 		u32 reg32bits;
148 		u64 tmp;
149 		u32 numReg;
150 		u32 part;
151 
152 		ret = -EIO;
153 		/* Determine which register the user wants */
154 		index = (u64)addr >> 2;
155 		numReg = index / 2;
156 		/* Determine which part of the register the user wants */
157 		if (index % 2)
158 			part = 1;  /* want the 2nd half of the register (right-most). */
159 		else
160 			part = 0;  /* want the 1st half of the register (left-most). */
161 
162 		/* Validate the input - check to see if address is on the wrong boundary
163 		 * or beyond the end of the user area
164 		 */
165 		if ((addr & 3) || numReg > PT_FPSCR)
166 			break;
167 
168 		CHECK_FULL_REGS(child->thread.regs);
169 		if (numReg >= PT_FPR0) {
170 			flush_fp_to_thread(child);
171 			tmp = ((unsigned long int *)child->thread.fpr)
172 				[FPRINDEX(numReg)];
173 		} else { /* register within PT_REGS struct */
174 			tmp = ptrace_get_reg(child, numReg);
175 		}
176 		reg32bits = ((u32*)&tmp)[part];
177 		ret = put_user(reg32bits, (u32 __user *)data);
178 		break;
179 	}
180 
181 	/*
182 	 * Write 4 bytes into the other process' storage
183 	 *  data is the 4 bytes that the user wants written
184 	 *  addr is a pointer in the user's storage that contains an
185 	 *	8 byte address in the other process where the 4 bytes
186 	 *	that is to be written
187 	 * (this is run in a 32-bit process looking at a 64-bit process)
188 	 * when I and D space are separate, these will need to be fixed.
189 	 */
190 	case PPC_PTRACE_POKETEXT_3264:
191 	case PPC_PTRACE_POKEDATA_3264: {
192 		u32 tmp = data;
193 		u32 __user * addrOthers;
194 
195 		/* Get the addr in the other process that we want to write into */
196 		ret = -EIO;
197 		if (get_user(addrOthers, (u32 __user * __user *)addr) != 0)
198 			break;
199 		ret = 0;
200 		if (access_process_vm(child, (u64)addrOthers, &tmp,
201 					sizeof(tmp), 1) == sizeof(tmp))
202 			break;
203 		ret = -EIO;
204 		break;
205 	}
206 
207 	/* write the word at location addr in the USER area */
208 	case PTRACE_POKEUSR: {
209 		unsigned long index;
210 
211 		ret = -EIO;
212 		/* convert to index and check */
213 		index = (unsigned long) addr >> 2;
214 		if ((addr & 3) || (index > PT_FPSCR32))
215 			break;
216 
217 		CHECK_FULL_REGS(child->thread.regs);
218 		if (index < PT_FPR0) {
219 			ret = ptrace_put_reg(child, index, data);
220 		} else {
221 			flush_fp_to_thread(child);
222 			/*
223 			 * the user space code considers the floating point
224 			 * to be an array of unsigned int (32 bits) - the
225 			 * index passed in is based on this assumption.
226 			 */
227 			((unsigned int *)child->thread.fpr)
228 				[FPRINDEX(index)] = data;
229 			ret = 0;
230 		}
231 		break;
232 	}
233 
234 	/*
235 	 * Write 4 bytes into the other process' pt_regs area
236 	 *  data is the 4 bytes that the user wants written
237 	 *  addr is the offset into the other process' pt_regs structure
238 	 *	that is to be written into
239 	 * (this is run in a 32-bit process looking at a 64-bit process)
240 	 */
241 	case PPC_PTRACE_POKEUSR_3264: {
242 		u32 index;
243 		u32 numReg;
244 
245 		ret = -EIO;
246 		/* Determine which register the user wants */
247 		index = (u64)addr >> 2;
248 		numReg = index / 2;
249 
250 		/*
251 		 * Validate the input - check to see if address is on the
252 		 * wrong boundary or beyond the end of the user area
253 		 */
254 		if ((addr & 3) || (numReg > PT_FPSCR))
255 			break;
256 		CHECK_FULL_REGS(child->thread.regs);
257 		if (numReg < PT_FPR0) {
258 			unsigned long freg = ptrace_get_reg(child, numReg);
259 			if (index % 2)
260 				freg = (freg & ~0xfffffffful) | (data & 0xfffffffful);
261 			else
262 				freg = (freg & 0xfffffffful) | (data << 32);
263 			ret = ptrace_put_reg(child, numReg, freg);
264 		} else {
265 			flush_fp_to_thread(child);
266 			((unsigned int *)child->thread.regs)[index] = data;
267 			ret = 0;
268 		}
269 		break;
270 	}
271 
272 	case PTRACE_GET_DEBUGREG: {
273 		ret = -EINVAL;
274 		/* We only support one DABR and no IABRS at the moment */
275 		if (addr > 0)
276 			break;
277 		ret = put_user(child->thread.dabr, (u32 __user *)data);
278 		break;
279 	}
280 
281 	case PTRACE_GETREGS:	/* Get all pt_regs from the child. */
282 		return copy_regset_to_user(
283 			child, task_user_regset_view(current), 0,
284 			0, PT_REGS_COUNT * sizeof(compat_long_t),
285 			compat_ptr(data));
286 
287 	case PTRACE_SETREGS:	/* Set all gp regs in the child. */
288 		return copy_regset_from_user(
289 			child, task_user_regset_view(current), 0,
290 			0, PT_REGS_COUNT * sizeof(compat_long_t),
291 			compat_ptr(data));
292 
293 	case PTRACE_GETFPREGS:
294 	case PTRACE_SETFPREGS:
295 	case PTRACE_GETVRREGS:
296 	case PTRACE_SETVRREGS:
297 	case PTRACE_GETVSRREGS:
298 	case PTRACE_SETVSRREGS:
299 	case PTRACE_GETREGS64:
300 	case PTRACE_SETREGS64:
301 	case PPC_PTRACE_GETFPREGS:
302 	case PPC_PTRACE_SETFPREGS:
303 	case PTRACE_KILL:
304 	case PTRACE_SINGLESTEP:
305 	case PTRACE_DETACH:
306 	case PTRACE_SET_DEBUGREG:
307 	case PTRACE_SYSCALL:
308 	case PTRACE_CONT:
309 		ret = arch_ptrace(child, request, addr, data);
310 		break;
311 
312 	/* Old reverse args ptrace callss */
313 	case PPC_PTRACE_GETREGS: /* Get GPRs 0 - 31. */
314 	case PPC_PTRACE_SETREGS: /* Set GPRs 0 - 31. */
315 		ret = compat_ptrace_old(child, request, addr, data);
316 		break;
317 
318 	default:
319 		ret = compat_ptrace_request(child, request, addr, data);
320 		break;
321 	}
322 
323 	return ret;
324 }
325