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), FOLL_FORCE);
 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), FOLL_FORCE);
 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),
 157                         FOLL_FORCE | FOLL_WRITE);
 158
 159         return copied != sizeof(val) ? -EIO : 0;
 160 }
 161
 162 static int
 163 write_tsk_long(struct task_struct *child,
 164                 unsigned long addr, unsigned long val)
 165 {
 166         int copied;
 167
 168         copied = access_process_vm(child, addr, &val, sizeof(val),
 169                         FOLL_FORCE | FOLL_WRITE);
 170
 171         return copied != sizeof(val) ? -EIO : 0;
 172 }
 173
 174 void user_enable_single_step(struct task_struct *child)
 175 {
 176         /* far_epc is the target of branch */
 177         unsigned int epc, far_epc = 0;
 178         unsigned long epc_insn, far_epc_insn;
 179         int ninsn_type;                 /* next insn type 0=16b, 1=32b */
 180         unsigned int tmp, tmp2;
 181         struct pt_regs *regs = task_pt_regs(child);
 182         child->thread.single_step = 1;
 183         child->thread.ss_nextcnt = 1;
 184         epc = regs->cp0_epc;
 185
 186         read_tsk_long(child, epc, &epc_insn);
 187
 188         if (is_16bitinsn(epc_insn)) {
 189                 if ((epc_insn & J16M) == J16) {
 190                         tmp = epc_insn & 0xFFE;
 191                         epc = (epc & 0xFFFFF000) | tmp;
 192                 } else if ((epc_insn & B16M) == B16) {
 193                         child->thread.ss_nextcnt = 2;
 194                         tmp = (epc_insn & 0xFF) << 1;
 195                         tmp = tmp << 23;
 196                         tmp = (unsigned int)((int) tmp >> 23);
 197                         far_epc = epc + tmp;
 198                         epc += 2;
 199                 } else if ((epc_insn & BR16M) == BR16) {
 200                         child->thread.ss_nextcnt = 2;
 201                         tmp = (epc_insn >> 4) & 0xF;
 202                         far_epc = regs->regs[tmp];
 203                         epc += 2;
 204                 } else
 205                         epc += 2;
 206         } else {
 207                 if ((epc_insn & J32M) == J32) {
 208                         tmp = epc_insn & 0x03FFFFFE;
 209                         tmp2 = tmp & 0x7FFF;
 210                         tmp = (((tmp >> 16) & 0x3FF) << 15) | tmp2;
 211                         epc = (epc & 0xFFC00000) | tmp;
 212                 } else if ((epc_insn & B32M) == B32) {
 213                         child->thread.ss_nextcnt = 2;
 214                         tmp = epc_insn & 0x03FFFFFE;    /* discard LK bit */
 215                         tmp2 = tmp & 0x3FF;
 216                         tmp = (((tmp >> 16) & 0x3FF) << 10) | tmp2; /* 20bit */
 217                         tmp = tmp << 12;
 218                         tmp = (unsigned int)((int) tmp >> 12);
 219                         far_epc = epc + tmp;
 220                         epc += 4;
 221                 } else if ((epc_insn & BR32M) == BR32) {
 222                         child->thread.ss_nextcnt = 2;
 223                         tmp = (epc_insn >> 16) & 0x1F;
 224                         far_epc = regs->regs[tmp];
 225                         epc += 4;
 226                 } else
 227                         epc += 4;
 228         }
 229
 230         if (child->thread.ss_nextcnt == 1) {
 231                 read_tsk_long(child, epc, &epc_insn);
 232
 233                 if (is_16bitinsn(epc_insn)) {
 234                         write_tsk_short(child, epc, SINGLESTEP16_INSN);
 235                         ninsn_type = 0;
 236                 } else {
 237                         write_tsk_long(child, epc, SINGLESTEP32_INSN);
 238                         ninsn_type = 1;
 239                 }
 240
 241                 if (ninsn_type == 0) {  /* 16bits */
 242                         child->thread.insn1_type = 0;
 243                         child->thread.addr1 = epc;
 244                          /* the insn may have 32bit data */
 245                         child->thread.insn1 = (short)epc_insn;
 246                 } else {
 247                         child->thread.insn1_type = 1;
 248                         child->thread.addr1 = epc;
 249                         child->thread.insn1 = epc_insn;
 250                 }
 251         } else {
 252                 /* branch! have two target child->thread.ss_nextcnt=2 */
 253                 read_tsk_long(child, epc, &epc_insn);
 254                 read_tsk_long(child, far_epc, &far_epc_insn);
 255                 if (is_16bitinsn(epc_insn)) {
 256                         write_tsk_short(child, epc, SINGLESTEP16_INSN);
 257                         ninsn_type = 0;
 258                 } else {
 259                         write_tsk_long(child, epc, SINGLESTEP32_INSN);
 260                         ninsn_type = 1;
 261                 }
 262
 263                 if (ninsn_type == 0) {  /* 16bits */
 264                         child->thread.insn1_type = 0;
 265                         child->thread.addr1 = epc;
 266                          /* the insn may have 32bit data */
 267                         child->thread.insn1 = (short)epc_insn;
 268                 } else {
 269                         child->thread.insn1_type = 1;
 270                         child->thread.addr1 = epc;
 271                         child->thread.insn1 = epc_insn;
 272                 }
 273
 274                 if (is_16bitinsn(far_epc_insn)) {
 275                         write_tsk_short(child, far_epc, SINGLESTEP16_INSN);
 276                         ninsn_type = 0;
 277                 } else {
 278                         write_tsk_long(child, far_epc, SINGLESTEP32_INSN);
 279                         ninsn_type = 1;
 280                 }
 281
 282                 if (ninsn_type == 0) {  /* 16bits */
 283                         child->thread.insn2_type = 0;
 284                         child->thread.addr2 = far_epc;
 285                          /* the insn may have 32bit data */
 286                         child->thread.insn2 = (short)far_epc_insn;
 287                 } else {
 288                         child->thread.insn2_type = 1;
 289                         child->thread.addr2 = far_epc;
 290                         child->thread.insn2 = far_epc_insn;
 291                 }
 292         }
 293 }
 294
 295 void user_disable_single_step(struct task_struct *child)
 296 {
 297         if (child->thread.insn1_type == 0)
 298                 write_tsk_short(child, child->thread.addr1,
 299                                 child->thread.insn1);
 300
 301         if (child->thread.insn1_type == 1)
 302                 write_tsk_long(child, child->thread.addr1,
 303                                 child->thread.insn1);
 304
 305         if (child->thread.ss_nextcnt == 2) {    /* branch */
 306                 if (child->thread.insn1_type == 0)
 307                         write_tsk_short(child, child->thread.addr1,
 308                                         child->thread.insn1);
 309                 if (child->thread.insn1_type == 1)
 310                         write_tsk_long(child, child->thread.addr1,
 311                                         child->thread.insn1);
 312                 if (child->thread.insn2_type == 0)
 313                         write_tsk_short(child, child->thread.addr2,
 314                                         child->thread.insn2);
 315                 if (child->thread.insn2_type == 1)
 316                         write_tsk_long(child, child->thread.addr2,
 317                                         child->thread.insn2);
 318         }
 319
 320         child->thread.single_step = 0;
 321         child->thread.ss_nextcnt = 0;
 322 }
 323
 324 void ptrace_disable(struct task_struct *child)
 325 {
 326         user_disable_single_step(child);
 327 }
 328
 329 long
 330 arch_ptrace(struct task_struct *child, long request,
 331             unsigned long addr, unsigned long data)
 332 {
 333         int ret;
 334         unsigned long __user *datap = (void __user *)data;
 335
 336         switch (request) {
 337         case PTRACE_GETREGS:
 338                 ret = copy_regset_to_user(child, &user_score_native_view,
 339                                                 REGSET_GENERAL,
 340                                                 0, sizeof(struct pt_regs),
 341                                                 datap);
 342                 break;
 343
 344         case PTRACE_SETREGS:
 345                 ret = copy_regset_from_user(child, &user_score_native_view,
 346                                                 REGSET_GENERAL,
 347                                                 0, sizeof(struct pt_regs),
 348                                                 datap);
 349                 break;
 350
 351         default:
 352                 ret = ptrace_request(child, request, addr, data);
 353                 break;
 354         }
 355
 356         return ret;
 357 }
 358
 359 /*
 360  * Notification of system call entry/exit
 361  * - triggered by current->work.syscall_trace
 362  */
 363 asmlinkage void do_syscall_trace(struct pt_regs *regs, int entryexit)
 364 {
 365         if (!(current->ptrace & PT_PTRACED))
 366                 return;
 367
 368         if (!test_thread_flag(TIF_SYSCALL_TRACE))
 369                 return;
 370
 371         /* The 0x80 provides a way for the tracing parent to distinguish
 372            between a syscall stop and SIGTRAP delivery. */
 373         ptrace_notify(SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD) ?
 374                         0x80 : 0));
 375
 376         /*
 377          * this isn't the same as continuing with a signal, but it will do
 378          * for normal use.  strace only continues with a signal if the
 379          * stopping signal is not SIGTRAP.  -brl
 380          */
 381         if (current->exit_code) {
 382                 send_sig(current->exit_code, current, 1);
 383                 current->exit_code = 0;
 384         }
 385 }