arch/powerpc/kernel/ptrace.c

   1 /*
   2  *  PowerPC version
   3  *    Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
   4  *
   5  *  Derived from "arch/m68k/kernel/ptrace.c"
   6  *  Copyright (C) 1994 by Hamish Macdonald
   7  *  Taken from linux/kernel/ptrace.c and modified for M680x0.
   8  *  linux/kernel/ptrace.c is by Ross Biro 1/23/92, edited by Linus Torvalds
   9  *
  10  * Modified by Cort Dougan (cort@hq.fsmlabs.com)
  11  * and Paul Mackerras (paulus@samba.org).
  12  *
  13  * This file is subject to the terms and conditions of the GNU General
  14  * Public License.  See the file README.legal in the main directory of
  15  * this archive for more details.
  16  */
  17
  18 #include <linux/kernel.h>
  19 #include <linux/sched.h>
  20 #include <linux/mm.h>
  21 #include <linux/smp.h>
  22 #include <linux/errno.h>
  23 #include <linux/ptrace.h>
  24 #include <linux/user.h>
  25 #include <linux/security.h>
  26 #include <linux/signal.h>
  27 #include <linux/seccomp.h>
  28 #include <linux/audit.h>
  29 #ifdef CONFIG_PPC32
  30 #include <linux/module.h>
  31 #endif
  32
  33 #include <asm/uaccess.h>
  34 #include <asm/page.h>
  35 #include <asm/pgtable.h>
  36 #include <asm/system.h>
  37
  38 #ifdef CONFIG_PPC64
  39 #include "ptrace-ppc64.h"
  40 #else
  41 #include "ptrace-ppc32.h"
  42 #endif
  43
  44 #include "ptrace-common.h"
  45
  46 /*
  47  * does not yet catch signals sent when the child dies.
  48  * in exit.c or in signal.c.
  49  */
  50
  51 /*
  52  * Called by kernel/ptrace.c when detaching..
  53  *
  54  * Make sure single step bits etc are not set.
  55  */
  56 void ptrace_disable(struct task_struct *child)
  57 {
  58         /* make sure the single step bit is not set. */
  59         clear_single_step(child);
  60 }
  61
  62 /*
  63  * Here are the old "legacy" powerpc specific getregs/setregs ptrace calls,
  64  * we mark them as obsolete now, they will be removed in a future version
  65  */
  66 static long arch_ptrace_old(struct task_struct *child, long request, long addr,
  67                             long data)
  68 {
  69         int ret = -EPERM;
  70
  71         switch(request) {
  72         case PPC_PTRACE_GETREGS: { /* Get GPRs 0 - 31. */
  73                 int i;
  74                 unsigned long *reg = &((unsigned long *)child->thread.regs)[0];
  75                 unsigned long __user *tmp = (unsigned long __user *)addr;
  76
  77                 for (i = 0; i < 32; i++) {
  78                         ret = put_user(*reg, tmp);
  79                         if (ret)
  80                                 break;
  81                         reg++;
  82                         tmp++;
  83                 }
  84                 break;
  85         }
  86
  87         case PPC_PTRACE_SETREGS: { /* Set GPRs 0 - 31. */
  88                 int i;
  89                 unsigned long *reg = &((unsigned long *)child->thread.regs)[0];
  90                 unsigned long __user *tmp = (unsigned long __user *)addr;
  91
  92                 for (i = 0; i < 32; i++) {
  93                         ret = get_user(*reg, tmp);
  94                         if (ret)
  95                                 break;
  96                         reg++;
  97                         tmp++;
  98                 }
  99                 break;
 100         }
 101
 102         case PPC_PTRACE_GETFPREGS: { /* Get FPRs 0 - 31. */
 103                 flush_fp_to_thread(child);
 104                 ret = get_fpregs((void __user *)addr, child, 0);
 105                 break;
 106         }
 107
 108         case PPC_PTRACE_SETFPREGS: { /* Get FPRs 0 - 31. */
 109                 flush_fp_to_thread(child);
 110                 ret = set_fpregs((void __user *)addr, child, 0);
 111                 break;
 112         }
 113
 114         }
 115         return ret;
 116 }
 117
 118 long arch_ptrace(struct task_struct *child, long request, long addr, long data)
 119 {
 120         int ret = -EPERM;
 121
 122         switch (request) {
 123         /* when I and D space are separate, these will need to be fixed. */
 124         case PTRACE_PEEKTEXT: /* read word at location addr. */
 125         case PTRACE_PEEKDATA: {
 126                 unsigned long tmp;
 127                 int copied;
 128
 129                 copied = access_process_vm(child, addr, &tmp, sizeof(tmp), 0);
 130                 ret = -EIO;
 131                 if (copied != sizeof(tmp))
 132                         break;
 133                 ret = put_user(tmp,(unsigned long __user *) data);
 134                 break;
 135         }
 136
 137         /* read the word at location addr in the USER area. */
 138         case PTRACE_PEEKUSR: {
 139                 unsigned long index, tmp;
 140
 141                 ret = -EIO;
 142                 /* convert to index and check */
 143 #ifdef CONFIG_PPC32
 144                 index = (unsigned long) addr >> 2;
 145                 if ((addr & 3) || (index > PT_FPSCR)
 146                     || (child->thread.regs == NULL))
 147 #else
 148                 index = (unsigned long) addr >> 3;
 149                 if ((addr & 7) || (index > PT_FPSCR))
 150 #endif
 151                         break;
 152
 153 #ifdef CONFIG_PPC32
 154                 CHECK_FULL_REGS(child->thread.regs);
 155 #endif
 156                 if (index < PT_FPR0) {
 157                         tmp = get_reg(child, (int) index);
 158                 } else {
 159                         flush_fp_to_thread(child);
 160                         tmp = ((unsigned long *)child->thread.fpr)[index - PT_FPR0];
 161                 }
 162                 ret = put_user(tmp,(unsigned long __user *) data);
 163                 break;
 164         }
 165
 166         /* If I and D space are separate, this will have to be fixed. */
 167         case PTRACE_POKETEXT: /* write the word at location addr. */
 168         case PTRACE_POKEDATA:
 169                 ret = 0;
 170                 if (access_process_vm(child, addr, &data, sizeof(data), 1)
 171                                 == sizeof(data))
 172                         break;
 173                 ret = -EIO;
 174                 break;
 175
 176         /* write the word at location addr in the USER area */
 177         case PTRACE_POKEUSR: {
 178                 unsigned long index;
 179
 180                 ret = -EIO;
 181                 /* convert to index and check */
 182 #ifdef CONFIG_PPC32
 183                 index = (unsigned long) addr >> 2;
 184                 if ((addr & 3) || (index > PT_FPSCR)
 185                     || (child->thread.regs == NULL))
 186 #else
 187                 index = (unsigned long) addr >> 3;
 188                 if ((addr & 7) || (index > PT_FPSCR))
 189 #endif
 190                         break;
 191
 192 #ifdef CONFIG_PPC32
 193                 CHECK_FULL_REGS(child->thread.regs);
 194 #endif
 195                 if (index == PT_ORIG_R3)
 196                         break;
 197                 if (index < PT_FPR0) {
 198                         ret = put_reg(child, index, data);
 199                 } else {
 200                         flush_fp_to_thread(child);
 201                         ((unsigned long *)child->thread.fpr)[index - PT_FPR0] = data;
 202                         ret = 0;
 203                 }
 204                 break;
 205         }
 206
 207         case PTRACE_SYSCALL: /* continue and stop at next (return from) syscall */
 208         case PTRACE_CONT: { /* restart after signal. */
 209                 ret = -EIO;
 210                 if (!valid_signal(data))
 211                         break;
 212                 if (request == PTRACE_SYSCALL)
 213                         set_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
 214                 else
 215                         clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
 216                 child->exit_code = data;
 217                 /* make sure the single step bit is not set. */
 218                 clear_single_step(child);
 219                 wake_up_process(child);
 220                 ret = 0;
 221                 break;
 222         }
 223
 224 /*
 225  * make the child exit.  Best I can do is send it a sigkill.
 226  * perhaps it should be put in the status that it wants to
 227  * exit.
 228  */
 229         case PTRACE_KILL: {
 230                 ret = 0;
 231                 if (child->exit_state == EXIT_ZOMBIE)   /* already dead */
 232                         break;
 233                 child->exit_code = SIGKILL;
 234                 /* make sure the single step bit is not set. */
 235                 clear_single_step(child);
 236                 wake_up_process(child);
 237                 break;
 238         }
 239
 240         case PTRACE_SINGLESTEP: {  /* set the trap flag. */
 241                 ret = -EIO;
 242                 if (!valid_signal(data))
 243                         break;
 244                 clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
 245                 set_single_step(child);
 246                 child->exit_code = data;
 247                 /* give it a chance to run. */
 248                 wake_up_process(child);
 249                 ret = 0;
 250                 break;
 251         }
 252
 253 #ifdef CONFIG_PPC64
 254         case PTRACE_GET_DEBUGREG: {
 255                 ret = -EINVAL;
 256                 /* We only support one DABR and no IABRS at the moment */
 257                 if (addr > 0)
 258                         break;
 259                 ret = put_user(child->thread.dabr,
 260                                (unsigned long __user *)data);
 261                 break;
 262         }
 263
 264         case PTRACE_SET_DEBUGREG:
 265                 ret = ptrace_set_debugreg(child, addr, data);
 266                 break;
 267 #endif
 268
 269         case PTRACE_DETACH:
 270                 ret = ptrace_detach(child, data);
 271                 break;
 272
 273 #ifdef CONFIG_PPC64
 274         case PTRACE_GETREGS64:
 275 #endif
 276         case PTRACE_GETREGS: { /* Get all pt_regs from the child. */
 277                 int ui;
 278                 if (!access_ok(VERIFY_WRITE, (void __user *)data,
 279                                sizeof(struct pt_regs))) {
 280                         ret = -EIO;
 281                         break;
 282                 }
 283                 ret = 0;
 284                 for (ui = 0; ui < PT_REGS_COUNT; ui ++) {
 285                         ret |= __put_user(get_reg(child, ui),
 286                                           (unsigned long __user *) data);
 287                         data += sizeof(long);
 288                 }
 289                 break;
 290         }
 291
 292 #ifdef CONFIG_PPC64
 293         case PTRACE_SETREGS64:
 294 #endif
 295         case PTRACE_SETREGS: { /* Set all gp regs in the child. */
 296                 unsigned long tmp;
 297                 int ui;
 298                 if (!access_ok(VERIFY_READ, (void __user *)data,
 299                                sizeof(struct pt_regs))) {
 300                         ret = -EIO;
 301                         break;
 302                 }
 303                 ret = 0;
 304                 for (ui = 0; ui < PT_REGS_COUNT; ui ++) {
 305                         ret = __get_user(tmp, (unsigned long __user *) data);
 306                         if (ret)
 307                                 break;
 308                         put_reg(child, ui, tmp);
 309                         data += sizeof(long);
 310                 }
 311                 break;
 312         }
 313
 314         case PTRACE_GETFPREGS: { /* Get the child FPU state (FPR0...31 + FPSCR) */
 315                 flush_fp_to_thread(child);
 316                 ret = get_fpregs((void __user *)data, child, 1);
 317                 break;
 318         }
 319
 320         case PTRACE_SETFPREGS: { /* Set the child FPU state (FPR0...31 + FPSCR) */
 321                 flush_fp_to_thread(child);
 322                 ret = set_fpregs((void __user *)data, child, 1);
 323                 break;
 324         }
 325
 326 #ifdef CONFIG_ALTIVEC
 327         case PTRACE_GETVRREGS:
 328                 /* Get the child altivec register state. */
 329                 flush_altivec_to_thread(child);
 330                 ret = get_vrregs((unsigned long __user *)data, child);
 331                 break;
 332
 333         case PTRACE_SETVRREGS:
 334                 /* Set the child altivec register state. */
 335                 flush_altivec_to_thread(child);
 336                 ret = set_vrregs(child, (unsigned long __user *)data);
 337                 break;
 338 #endif
 339 #ifdef CONFIG_SPE
 340         case PTRACE_GETEVRREGS:
 341                 /* Get the child spe register state. */
 342                 if (child->thread.regs->msr & MSR_SPE)
 343                         giveup_spe(child);
 344                 ret = get_evrregs((unsigned long __user *)data, child);
 345                 break;
 346
 347         case PTRACE_SETEVRREGS:
 348                 /* Set the child spe register state. */
 349                 /* this is to clear the MSR_SPE bit to force a reload
 350                  * of register state from memory */
 351                 if (child->thread.regs->msr & MSR_SPE)
 352                         giveup_spe(child);
 353                 ret = set_evrregs(child, (unsigned long __user *)data);
 354                 break;
 355 #endif
 356
 357         /* Old reverse args ptrace callss */
 358         case PPC_PTRACE_GETREGS: /* Get GPRs 0 - 31. */
 359         case PPC_PTRACE_SETREGS: /* Set GPRs 0 - 31. */
 360         case PPC_PTRACE_GETFPREGS: /* Get FPRs 0 - 31. */
 361         case PPC_PTRACE_SETFPREGS: /* Get FPRs 0 - 31. */
 362                 ret = arch_ptrace_old(child, request, addr, data);
 363                 break;
 364
 365         default:
 366                 ret = ptrace_request(child, request, addr, data);
 367                 break;
 368         }
 369         return ret;
 370 }
 371
 372 static void do_syscall_trace(void)
 373 {
 374         /* the 0x80 provides a way for the tracing parent to distinguish
 375            between a syscall stop and SIGTRAP delivery */
 376         ptrace_notify(SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD)
 377                                  ? 0x80 : 0));
 378
 379         /*
 380          * this isn't the same as continuing with a signal, but it will do
 381          * for normal use.  strace only continues with a signal if the
 382          * stopping signal is not SIGTRAP.  -brl
 383          */
 384         if (current->exit_code) {
 385                 send_sig(current->exit_code, current, 1);
 386                 current->exit_code = 0;
 387         }
 388 }
 389
 390 void do_syscall_trace_enter(struct pt_regs *regs)
 391 {
 392         secure_computing(regs->gpr[0]);
 393
 394         if (test_thread_flag(TIF_SYSCALL_TRACE)
 395             && (current->ptrace & PT_PTRACED))
 396                 do_syscall_trace();
 397
 398         if (unlikely(current->audit_context)) {
 399 #ifdef CONFIG_PPC64
 400                 if (!test_thread_flag(TIF_32BIT))
 401                         audit_syscall_entry(AUDIT_ARCH_PPC64,
 402                                             regs->gpr[0],
 403                                             regs->gpr[3], regs->gpr[4],
 404                                             regs->gpr[5], regs->gpr[6]);
 405                 else
 406 #endif
 407                         audit_syscall_entry(AUDIT_ARCH_PPC,
 408                                             regs->gpr[0],
 409                                             regs->gpr[3] & 0xffffffff,
 410                                             regs->gpr[4] & 0xffffffff,
 411                                             regs->gpr[5] & 0xffffffff,
 412                                             regs->gpr[6] & 0xffffffff);
 413         }
 414 }
 415
 416 void do_syscall_trace_leave(struct pt_regs *regs)
 417 {
 418         if (unlikely(current->audit_context))
 419                 audit_syscall_exit((regs->ccr&0x10000000)?AUDITSC_FAILURE:AUDITSC_SUCCESS,
 420                                    regs->result);
 421
 422         if ((test_thread_flag(TIF_SYSCALL_TRACE)
 423              || test_thread_flag(TIF_SINGLESTEP))
 424             && (current->ptrace & PT_PTRACED))
 425                 do_syscall_trace();
 426 }