score: fix off-by-one index into syscall table
[linux-2.6.git] / arch / score / kernel / ptrace.c
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  */
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  */
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
115 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
116 {
117         return &user_score_native_view;
118 }
119
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
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
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
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
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
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
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
322 void ptrace_disable(struct task_struct *child)
323 {
324         user_disable_single_step(child);
325 }
326
327 long
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  */
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 }