1 /*
2 * arch/score/kernel/ptrace.c
3 *
4 * Score Processor version.
5 *
6 * Copyright (C) 2009 Sunplus Core Technology Co., Ltd.
7 * Chen Liqin <liqin.chen@sunplusct.com>
8 * Lennox Wu <lennox.wu@sunplusct.com>
9 *
10 * This program is free software; you can redistribute it and/or modify
11 * it under the terms of the GNU General Public License as published by
12 * the Free Software Foundation; either version 2 of the License, or
13 * (at your option) any later version.
14 *
15 * This program is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 * GNU General Public License for more details.
19 *
20 * You should have received a copy of the GNU General Public License
21 * along with this program; if not, see the file COPYING, or write
22 * to the Free Software Foundation, Inc.,
23 * 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
24 */
25
26 #include <linux/elf.h>
27 #include <linux/kernel.h>
28 #include <linux/mm.h>
29 #include <linux/ptrace.h>
30 #include <linux/regset.h>
31 #include <linux/sched/task_stack.h>
32
33 #include <linux/uaccess.h>
34
35 /*
36 * retrieve the contents of SCORE userspace general registers
37 */
genregs_get(struct task_struct * target,const struct user_regset * regset,unsigned int pos,unsigned int count,void * kbuf,void __user * ubuf)38 static int genregs_get(struct task_struct *target,
39 const struct user_regset *regset,
40 unsigned int pos, unsigned int count,
41 void *kbuf, void __user *ubuf)
42 {
43 const struct pt_regs *regs = task_pt_regs(target);
44 int ret;
45
46 /* skip 9 * sizeof(unsigned long) not use for pt_regs */
47 ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
48 0, offsetof(struct pt_regs, regs));
49
50 /* r0 - r31, cel, ceh, sr0, sr1, sr2, epc, ema, psr, ecr, condition */
51 ret = user_regset_copyout(&pos, &count, &kbuf, &ubuf,
52 regs->regs,
53 offsetof(struct pt_regs, regs),
54 offsetof(struct pt_regs, cp0_condition));
55
56 if (!ret)
57 ret = user_regset_copyout_zero(&pos, &count, &kbuf, &ubuf,
58 sizeof(struct pt_regs), -1);
59
60 return ret;
61 }
62
63 /*
64 * update the contents of the SCORE userspace general registers
65 */
genregs_set(struct task_struct * target,const struct user_regset * regset,unsigned int pos,unsigned int count,const void * kbuf,const void __user * ubuf)66 static int genregs_set(struct task_struct *target,
67 const struct user_regset *regset,
68 unsigned int pos, unsigned int count,
69 const void *kbuf, const void __user *ubuf)
70 {
71 struct pt_regs *regs = task_pt_regs(target);
72 int ret;
73
74 /* skip 9 * sizeof(unsigned long) */
75 ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
76 0, offsetof(struct pt_regs, regs));
77
78 /* r0 - r31, cel, ceh, sr0, sr1, sr2, epc, ema, psr, ecr, condition */
79 ret = user_regset_copyin(&pos, &count, &kbuf, &ubuf,
80 regs->regs,
81 offsetof(struct pt_regs, regs),
82 offsetof(struct pt_regs, cp0_condition));
83
84 if (!ret)
85 ret = user_regset_copyin_ignore(&pos, &count, &kbuf, &ubuf,
86 sizeof(struct pt_regs), -1);
87
88 return ret;
89 }
90
91 /*
92 * Define the register sets available on the score7 under Linux
93 */
94 enum score7_regset {
95 REGSET_GENERAL,
96 };
97
98 static const struct user_regset score7_regsets[] = {
99 [REGSET_GENERAL] = {
100 .core_note_type = NT_PRSTATUS,
101 .n = ELF_NGREG,
102 .size = sizeof(long),
103 .align = sizeof(long),
104 .get = genregs_get,
105 .set = genregs_set,
106 },
107 };
108
109 static const struct user_regset_view user_score_native_view = {
110 .name = "score7",
111 .e_machine = EM_SCORE7,
112 .regsets = score7_regsets,
113 .n = ARRAY_SIZE(score7_regsets),
114 };
115
task_user_regset_view(struct task_struct * task)116 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
117 {
118 return &user_score_native_view;
119 }
120
is_16bitinsn(unsigned long insn)121 static int is_16bitinsn(unsigned long insn)
122 {
123 if ((insn & INSN32_MASK) == INSN32_MASK)
124 return 0;
125 else
126 return 1;
127 }
128
129 int
read_tsk_long(struct task_struct * child,unsigned long addr,unsigned long * res)130 read_tsk_long(struct task_struct *child,
131 unsigned long addr, unsigned long *res)
132 {
133 int copied;
134
135 copied = access_process_vm(child, addr, res, sizeof(*res), FOLL_FORCE);
136
137 return copied != sizeof(*res) ? -EIO : 0;
138 }
139
140 int
read_tsk_short(struct task_struct * child,unsigned long addr,unsigned short * res)141 read_tsk_short(struct task_struct *child,
142 unsigned long addr, unsigned short *res)
143 {
144 int copied;
145
146 copied = access_process_vm(child, addr, res, sizeof(*res), FOLL_FORCE);
147
148 return copied != sizeof(*res) ? -EIO : 0;
149 }
150
151 static int
write_tsk_short(struct task_struct * child,unsigned long addr,unsigned short val)152 write_tsk_short(struct task_struct *child,
153 unsigned long addr, unsigned short val)
154 {
155 int copied;
156
157 copied = access_process_vm(child, addr, &val, sizeof(val),
158 FOLL_FORCE | FOLL_WRITE);
159
160 return copied != sizeof(val) ? -EIO : 0;
161 }
162
163 static int
write_tsk_long(struct task_struct * child,unsigned long addr,unsigned long val)164 write_tsk_long(struct task_struct *child,
165 unsigned long addr, unsigned long val)
166 {
167 int copied;
168
169 copied = access_process_vm(child, addr, &val, sizeof(val),
170 FOLL_FORCE | FOLL_WRITE);
171
172 return copied != sizeof(val) ? -EIO : 0;
173 }
174
user_enable_single_step(struct task_struct * child)175 void user_enable_single_step(struct task_struct *child)
176 {
177 /* far_epc is the target of branch */
178 unsigned int epc, far_epc = 0;
179 unsigned long epc_insn, far_epc_insn;
180 int ninsn_type; /* next insn type 0=16b, 1=32b */
181 unsigned int tmp, tmp2;
182 struct pt_regs *regs = task_pt_regs(child);
183 child->thread.single_step = 1;
184 child->thread.ss_nextcnt = 1;
185 epc = regs->cp0_epc;
186
187 read_tsk_long(child, epc, &epc_insn);
188
189 if (is_16bitinsn(epc_insn)) {
190 if ((epc_insn & J16M) == J16) {
191 tmp = epc_insn & 0xFFE;
192 epc = (epc & 0xFFFFF000) | tmp;
193 } else if ((epc_insn & B16M) == B16) {
194 child->thread.ss_nextcnt = 2;
195 tmp = (epc_insn & 0xFF) << 1;
196 tmp = tmp << 23;
197 tmp = (unsigned int)((int) tmp >> 23);
198 far_epc = epc + tmp;
199 epc += 2;
200 } else if ((epc_insn & BR16M) == BR16) {
201 child->thread.ss_nextcnt = 2;
202 tmp = (epc_insn >> 4) & 0xF;
203 far_epc = regs->regs[tmp];
204 epc += 2;
205 } else
206 epc += 2;
207 } else {
208 if ((epc_insn & J32M) == J32) {
209 tmp = epc_insn & 0x03FFFFFE;
210 tmp2 = tmp & 0x7FFF;
211 tmp = (((tmp >> 16) & 0x3FF) << 15) | tmp2;
212 epc = (epc & 0xFFC00000) | tmp;
213 } else if ((epc_insn & B32M) == B32) {
214 child->thread.ss_nextcnt = 2;
215 tmp = epc_insn & 0x03FFFFFE; /* discard LK bit */
216 tmp2 = tmp & 0x3FF;
217 tmp = (((tmp >> 16) & 0x3FF) << 10) | tmp2; /* 20bit */
218 tmp = tmp << 12;
219 tmp = (unsigned int)((int) tmp >> 12);
220 far_epc = epc + tmp;
221 epc += 4;
222 } else if ((epc_insn & BR32M) == BR32) {
223 child->thread.ss_nextcnt = 2;
224 tmp = (epc_insn >> 16) & 0x1F;
225 far_epc = regs->regs[tmp];
226 epc += 4;
227 } else
228 epc += 4;
229 }
230
231 if (child->thread.ss_nextcnt == 1) {
232 read_tsk_long(child, epc, &epc_insn);
233
234 if (is_16bitinsn(epc_insn)) {
235 write_tsk_short(child, epc, SINGLESTEP16_INSN);
236 ninsn_type = 0;
237 } else {
238 write_tsk_long(child, epc, SINGLESTEP32_INSN);
239 ninsn_type = 1;
240 }
241
242 if (ninsn_type == 0) { /* 16bits */
243 child->thread.insn1_type = 0;
244 child->thread.addr1 = epc;
245 /* the insn may have 32bit data */
246 child->thread.insn1 = (short)epc_insn;
247 } else {
248 child->thread.insn1_type = 1;
249 child->thread.addr1 = epc;
250 child->thread.insn1 = epc_insn;
251 }
252 } else {
253 /* branch! have two target child->thread.ss_nextcnt=2 */
254 read_tsk_long(child, epc, &epc_insn);
255 read_tsk_long(child, far_epc, &far_epc_insn);
256 if (is_16bitinsn(epc_insn)) {
257 write_tsk_short(child, epc, SINGLESTEP16_INSN);
258 ninsn_type = 0;
259 } else {
260 write_tsk_long(child, epc, SINGLESTEP32_INSN);
261 ninsn_type = 1;
262 }
263
264 if (ninsn_type == 0) { /* 16bits */
265 child->thread.insn1_type = 0;
266 child->thread.addr1 = epc;
267 /* the insn may have 32bit data */
268 child->thread.insn1 = (short)epc_insn;
269 } else {
270 child->thread.insn1_type = 1;
271 child->thread.addr1 = epc;
272 child->thread.insn1 = epc_insn;
273 }
274
275 if (is_16bitinsn(far_epc_insn)) {
276 write_tsk_short(child, far_epc, SINGLESTEP16_INSN);
277 ninsn_type = 0;
278 } else {
279 write_tsk_long(child, far_epc, SINGLESTEP32_INSN);
280 ninsn_type = 1;
281 }
282
283 if (ninsn_type == 0) { /* 16bits */
284 child->thread.insn2_type = 0;
285 child->thread.addr2 = far_epc;
286 /* the insn may have 32bit data */
287 child->thread.insn2 = (short)far_epc_insn;
288 } else {
289 child->thread.insn2_type = 1;
290 child->thread.addr2 = far_epc;
291 child->thread.insn2 = far_epc_insn;
292 }
293 }
294 }
295
user_disable_single_step(struct task_struct * child)296 void user_disable_single_step(struct task_struct *child)
297 {
298 if (child->thread.insn1_type == 0)
299 write_tsk_short(child, child->thread.addr1,
300 child->thread.insn1);
301
302 if (child->thread.insn1_type == 1)
303 write_tsk_long(child, child->thread.addr1,
304 child->thread.insn1);
305
306 if (child->thread.ss_nextcnt == 2) { /* branch */
307 if (child->thread.insn1_type == 0)
308 write_tsk_short(child, child->thread.addr1,
309 child->thread.insn1);
310 if (child->thread.insn1_type == 1)
311 write_tsk_long(child, child->thread.addr1,
312 child->thread.insn1);
313 if (child->thread.insn2_type == 0)
314 write_tsk_short(child, child->thread.addr2,
315 child->thread.insn2);
316 if (child->thread.insn2_type == 1)
317 write_tsk_long(child, child->thread.addr2,
318 child->thread.insn2);
319 }
320
321 child->thread.single_step = 0;
322 child->thread.ss_nextcnt = 0;
323 }
324
ptrace_disable(struct task_struct * child)325 void ptrace_disable(struct task_struct *child)
326 {
327 user_disable_single_step(child);
328 }
329
330 long
arch_ptrace(struct task_struct * child,long request,unsigned long addr,unsigned long data)331 arch_ptrace(struct task_struct *child, long request,
332 unsigned long addr, unsigned long data)
333 {
334 int ret;
335 unsigned long __user *datap = (void __user *)data;
336
337 switch (request) {
338 case PTRACE_GETREGS:
339 ret = copy_regset_to_user(child, &user_score_native_view,
340 REGSET_GENERAL,
341 0, sizeof(struct pt_regs),
342 datap);
343 break;
344
345 case PTRACE_SETREGS:
346 ret = copy_regset_from_user(child, &user_score_native_view,
347 REGSET_GENERAL,
348 0, sizeof(struct pt_regs),
349 datap);
350 break;
351
352 default:
353 ret = ptrace_request(child, request, addr, data);
354 break;
355 }
356
357 return ret;
358 }
359
360 /*
361 * Notification of system call entry/exit
362 * - triggered by current->work.syscall_trace
363 */
do_syscall_trace(struct pt_regs * regs,int entryexit)364 asmlinkage void do_syscall_trace(struct pt_regs *regs, int entryexit)
365 {
366 if (!(current->ptrace & PT_PTRACED))
367 return;
368
369 if (!test_thread_flag(TIF_SYSCALL_TRACE))
370 return;
371
372 /* The 0x80 provides a way for the tracing parent to distinguish
373 between a syscall stop and SIGTRAP delivery. */
374 ptrace_notify(SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD) ?
375 0x80 : 0));
376
377 /*
378 * this isn't the same as continuing with a signal, but it will do
379 * for normal use. strace only continues with a signal if the
380 * stopping signal is not SIGTRAP. -brl
381 */
382 if (current->exit_code) {
383 send_sig(current->exit_code, current, 1);
384 current->exit_code = 0;
385 }
386 }
387