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 #include <linux/sched/task_stack.h>
  32
  33 #include <linux/uaccess.h>
  34
  35 /*
  36  * retrieve the contents of SCORE userspace general registers
  37  */
  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  */
  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
 116 const struct user_regset_view *task_user_regset_view(struct task_struct *task)
 117 {
 118         return &user_score_native_view;
 119 }
 120
 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
 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
 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
 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
 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
 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
 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
 325 void ptrace_disable(struct task_struct *child)
 326 {
 327         user_disable_single_step(child);
 328 }
 329
 330 long
 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  */
 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 }