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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/errno.h>
25 #include <linux/ptrace.h>
26 #include <linux/regset.h>
27 #include <linux/user.h>
28 #include <linux/security.h>
29 #include <linux/signal.h>
30 #include <linux/compat.h>
31 
32 #include <asm/uaccess.h>
33 #include <asm/page.h>
34 #include <asm/pgtable.h>
35 #include <asm/switch_to.h>
36 
37 /*
38  * does not yet catch signals sent when the child dies.
39  * in exit.c or in signal.c.
40  */
41 
42 /* Macros to workout the correct index for the FPR in the thread struct */
43 #define FPRNUMBER(i) (((i) - PT_FPR0) >> 1)
44 #define FPRHALF(i) (((i) - PT_FPR0) & 1)
45 #define FPRINDEX(i) TS_FPRWIDTH * FPRNUMBER(i) * 2 + FPRHALF(i)
46 
compat_arch_ptrace(struct task_struct * child,compat_long_t request,compat_ulong_t caddr,compat_ulong_t cdata)47 long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
48 			compat_ulong_t caddr, compat_ulong_t cdata)
49 {
50 	unsigned long addr = caddr;
51 	unsigned long data = cdata;
52 	int ret;
53 
54 	switch (request) {
55 	/*
56 	 * Read 4 bytes of the other process' storage
57 	 *  data is a pointer specifying where the user wants the
58 	 *	4 bytes copied into
59 	 *  addr is a pointer in the user's storage that contains an 8 byte
60 	 *	address in the other process of the 4 bytes that is to be read
61 	 * (this is run in a 32-bit process looking at a 64-bit process)
62 	 * when I and D space are separate, these will need to be fixed.
63 	 */
64 	case PPC_PTRACE_PEEKTEXT_3264:
65 	case PPC_PTRACE_PEEKDATA_3264: {
66 		u32 tmp;
67 		int copied;
68 		u32 __user * addrOthers;
69 
70 		ret = -EIO;
71 
72 		/* Get the addr in the other process that we want to read */
73 		if (get_user(addrOthers, (u32 __user * __user *)addr) != 0)
74 			break;
75 
76 		copied = ptrace_access_vm(child, (u64)addrOthers, &tmp,
77 				sizeof(tmp), FOLL_FORCE);
78 		if (copied != sizeof(tmp))
79 			break;
80 		ret = put_user(tmp, (u32 __user *)data);
81 		break;
82 	}
83 
84 	/* Read a register (specified by ADDR) out of the "user area" */
85 	case PTRACE_PEEKUSR: {
86 		int index;
87 		unsigned long tmp;
88 
89 		ret = -EIO;
90 		/* convert to index and check */
91 		index = (unsigned long) addr >> 2;
92 		if ((addr & 3) || (index > PT_FPSCR32))
93 			break;
94 
95 		CHECK_FULL_REGS(child->thread.regs);
96 		if (index < PT_FPR0) {
97 			ret = ptrace_get_reg(child, index, &tmp);
98 			if (ret)
99 				break;
100 		} else {
101 			flush_fp_to_thread(child);
102 			/*
103 			 * the user space code considers the floating point
104 			 * to be an array of unsigned int (32 bits) - the
105 			 * index passed in is based on this assumption.
106 			 */
107 			tmp = ((unsigned int *)child->thread.fp_state.fpr)
108 				[FPRINDEX(index)];
109 		}
110 		ret = put_user((unsigned int)tmp, (u32 __user *)data);
111 		break;
112 	}
113 
114 	/*
115 	 * Read 4 bytes out of the other process' pt_regs area
116 	 *  data is a pointer specifying where the user wants the
117 	 *	4 bytes copied into
118 	 *  addr is the offset into the other process' pt_regs structure
119 	 *	that is to be read
120 	 * (this is run in a 32-bit process looking at a 64-bit process)
121 	 */
122 	case PPC_PTRACE_PEEKUSR_3264: {
123 		u32 index;
124 		u32 reg32bits;
125 		u64 tmp;
126 		u32 numReg;
127 		u32 part;
128 
129 		ret = -EIO;
130 		/* Determine which register the user wants */
131 		index = (u64)addr >> 2;
132 		numReg = index / 2;
133 		/* Determine which part of the register the user wants */
134 		if (index % 2)
135 			part = 1;  /* want the 2nd half of the register (right-most). */
136 		else
137 			part = 0;  /* want the 1st half of the register (left-most). */
138 
139 		/* Validate the input - check to see if address is on the wrong boundary
140 		 * or beyond the end of the user area
141 		 */
142 		if ((addr & 3) || numReg > PT_FPSCR)
143 			break;
144 
145 		CHECK_FULL_REGS(child->thread.regs);
146 		if (numReg >= PT_FPR0) {
147 			flush_fp_to_thread(child);
148 			/* get 64 bit FPR */
149 			tmp = child->thread.fp_state.fpr[numReg - PT_FPR0][0];
150 		} else { /* register within PT_REGS struct */
151 			unsigned long tmp2;
152 			ret = ptrace_get_reg(child, numReg, &tmp2);
153 			if (ret)
154 				break;
155 			tmp = tmp2;
156 		}
157 		reg32bits = ((u32*)&tmp)[part];
158 		ret = put_user(reg32bits, (u32 __user *)data);
159 		break;
160 	}
161 
162 	/*
163 	 * Write 4 bytes into the other process' storage
164 	 *  data is the 4 bytes that the user wants written
165 	 *  addr is a pointer in the user's storage that contains an
166 	 *	8 byte address in the other process where the 4 bytes
167 	 *	that is to be written
168 	 * (this is run in a 32-bit process looking at a 64-bit process)
169 	 * when I and D space are separate, these will need to be fixed.
170 	 */
171 	case PPC_PTRACE_POKETEXT_3264:
172 	case PPC_PTRACE_POKEDATA_3264: {
173 		u32 tmp = data;
174 		u32 __user * addrOthers;
175 
176 		/* Get the addr in the other process that we want to write into */
177 		ret = -EIO;
178 		if (get_user(addrOthers, (u32 __user * __user *)addr) != 0)
179 			break;
180 		ret = 0;
181 		if (ptrace_access_vm(child, (u64)addrOthers, &tmp,
182 					sizeof(tmp),
183 					FOLL_FORCE | FOLL_WRITE) == sizeof(tmp))
184 			break;
185 		ret = -EIO;
186 		break;
187 	}
188 
189 	/* write the word at location addr in the USER area */
190 	case PTRACE_POKEUSR: {
191 		unsigned long index;
192 
193 		ret = -EIO;
194 		/* convert to index and check */
195 		index = (unsigned long) addr >> 2;
196 		if ((addr & 3) || (index > PT_FPSCR32))
197 			break;
198 
199 		CHECK_FULL_REGS(child->thread.regs);
200 		if (index < PT_FPR0) {
201 			ret = ptrace_put_reg(child, index, data);
202 		} else {
203 			flush_fp_to_thread(child);
204 			/*
205 			 * the user space code considers the floating point
206 			 * to be an array of unsigned int (32 bits) - the
207 			 * index passed in is based on this assumption.
208 			 */
209 			((unsigned int *)child->thread.fp_state.fpr)
210 				[FPRINDEX(index)] = data;
211 			ret = 0;
212 		}
213 		break;
214 	}
215 
216 	/*
217 	 * Write 4 bytes into the other process' pt_regs area
218 	 *  data is the 4 bytes that the user wants written
219 	 *  addr is the offset into the other process' pt_regs structure
220 	 *	that is to be written into
221 	 * (this is run in a 32-bit process looking at a 64-bit process)
222 	 */
223 	case PPC_PTRACE_POKEUSR_3264: {
224 		u32 index;
225 		u32 numReg;
226 
227 		ret = -EIO;
228 		/* Determine which register the user wants */
229 		index = (u64)addr >> 2;
230 		numReg = index / 2;
231 
232 		/*
233 		 * Validate the input - check to see if address is on the
234 		 * wrong boundary or beyond the end of the user area
235 		 */
236 		if ((addr & 3) || (numReg > PT_FPSCR))
237 			break;
238 		CHECK_FULL_REGS(child->thread.regs);
239 		if (numReg < PT_FPR0) {
240 			unsigned long freg;
241 			ret = ptrace_get_reg(child, numReg, &freg);
242 			if (ret)
243 				break;
244 			if (index % 2)
245 				freg = (freg & ~0xfffffffful) | (data & 0xfffffffful);
246 			else
247 				freg = (freg & 0xfffffffful) | (data << 32);
248 			ret = ptrace_put_reg(child, numReg, freg);
249 		} else {
250 			u64 *tmp;
251 			flush_fp_to_thread(child);
252 			/* get 64 bit FPR ... */
253 			tmp = &child->thread.fp_state.fpr[numReg - PT_FPR0][0];
254 			/* ... write the 32 bit part we want */
255 			((u32 *)tmp)[index % 2] = data;
256 			ret = 0;
257 		}
258 		break;
259 	}
260 
261 	case PTRACE_GET_DEBUGREG: {
262 #ifndef CONFIG_PPC_ADV_DEBUG_REGS
263 		unsigned long dabr_fake;
264 #endif
265 		ret = -EINVAL;
266 		/* We only support one DABR and no IABRS at the moment */
267 		if (addr > 0)
268 			break;
269 #ifdef CONFIG_PPC_ADV_DEBUG_REGS
270 		ret = put_user(child->thread.debug.dac1, (u32 __user *)data);
271 #else
272 		dabr_fake = (
273 			(child->thread.hw_brk.address & (~HW_BRK_TYPE_DABR)) |
274 			(child->thread.hw_brk.type & HW_BRK_TYPE_DABR));
275 		ret = put_user(dabr_fake, (u32 __user *)data);
276 #endif
277 		break;
278 	}
279 
280 	case PTRACE_GETREGS:	/* Get all pt_regs from the child. */
281 		return copy_regset_to_user(
282 			child, task_user_regset_view(current), 0,
283 			0, PT_REGS_COUNT * sizeof(compat_long_t),
284 			compat_ptr(data));
285 
286 	case PTRACE_SETREGS:	/* Set all gp regs in the child. */
287 		return copy_regset_from_user(
288 			child, task_user_regset_view(current), 0,
289 			0, PT_REGS_COUNT * sizeof(compat_long_t),
290 			compat_ptr(data));
291 
292 	case PTRACE_GETFPREGS:
293 	case PTRACE_SETFPREGS:
294 	case PTRACE_GETVRREGS:
295 	case PTRACE_SETVRREGS:
296 	case PTRACE_GETVSRREGS:
297 	case PTRACE_SETVSRREGS:
298 	case PTRACE_GETREGS64:
299 	case PTRACE_SETREGS64:
300 	case PTRACE_KILL:
301 	case PTRACE_SINGLESTEP:
302 	case PTRACE_DETACH:
303 	case PTRACE_SET_DEBUGREG:
304 	case PTRACE_SYSCALL:
305 	case PTRACE_CONT:
306 	case PPC_PTRACE_GETHWDBGINFO:
307 	case PPC_PTRACE_SETHWDEBUG:
308 	case PPC_PTRACE_DELHWDEBUG:
309 		ret = arch_ptrace(child, request, addr, data);
310 		break;
311 
312 	default:
313 		ret = compat_ptrace_request(child, request, addr, data);
314 		break;
315 	}
316 
317 	return ret;
318 }
319