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