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

source code of linux/arch/mips/kernel/ptrace32.c