arch/h8300/kernel/ptrace.c

   1 /*
   2  *  linux/arch/h8300/kernel/ptrace.c
   3  *
   4  *  Yoshinori Sato <ysato@users.sourceforge.jp>
   5  *
   6  *  Based on:
   7  *  linux/arch/m68k/kernel/ptrace.c
   8  *
   9  *  Copyright (C) 1994 by Hamish Macdonald
  10  *  Taken from linux/kernel/ptrace.c and modified for M680x0.
  11  *  linux/kernel/ptrace.c is by Ross Biro 1/23/92, edited by Linus Torvalds
  12  *
  13  * This file is subject to the terms and conditions of the GNU General
  14  * Public License.  See the file COPYING 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/smp_lock.h>
  23 #include <linux/errno.h>
  24 #include <linux/ptrace.h>
  25 #include <linux/user.h>
  26 #include <linux/config.h>
  27
  28 #include <asm/uaccess.h>
  29 #include <asm/page.h>
  30 #include <asm/pgtable.h>
  31 #include <asm/system.h>
  32 #include <asm/processor.h>
  33 #include <asm/signal.h>
  34
  35 /* cpu depend functions */
  36 extern long h8300_get_reg(struct task_struct *task, int regno);
  37 extern int  h8300_put_reg(struct task_struct *task, int regno, unsigned long data);
  38 extern void h8300_disable_trace(struct task_struct *child);
  39 extern void h8300_enable_trace(struct task_struct *child);
  40
  41 /*
  42  * does not yet catch signals sent when the child dies.
  43  * in exit.c or in signal.c.
  44  */
  45
  46 inline
  47 static int read_long(struct task_struct * tsk, unsigned long addr,
  48         unsigned long * result)
  49 {
  50         *result = *(unsigned long *)addr;
  51         return 0;
  52 }
  53
  54 void ptrace_disable(struct task_struct *child)
  55 {
  56         h8300_disable_trace(child);
  57 }
  58
  59 asmlinkage int sys_ptrace(long request, long pid, long addr, long data)
  60 {
  61         struct task_struct *child;
  62         int ret;
  63
  64         lock_kernel();
  65         ret = -EPERM;
  66         if (request == PTRACE_TRACEME) {
  67                 /* are we already being traced? */
  68                 if (current->ptrace & PT_PTRACED)
  69                         goto out;
  70                 /* set the ptrace bit in the process flags. */
  71                 current->ptrace |= PT_PTRACED;
  72                 ret = 0;
  73                 goto out;
  74         }
  75         ret = -ESRCH;
  76         read_lock(&tasklist_lock);
  77         child = find_task_by_pid(pid);
  78         if (child)
  79                 get_task_struct(child);
  80         read_unlock(&tasklist_lock);
  81         if (!child)
  82                 goto out;
  83
  84         ret = -EPERM;
  85         if (pid == 1)           /* you may not mess with init */
  86                 goto out_tsk;
  87
  88         if (request == PTRACE_ATTACH) {
  89                 ret = ptrace_attach(child);
  90                 goto out_tsk;
  91         }
  92         ret = ptrace_check_attach(child, request == PTRACE_KILL);
  93         if (ret < 0)
  94                 goto out_tsk;
  95
  96         switch (request) {
  97                 case PTRACE_PEEKTEXT: /* read word at location addr. */
  98                 case PTRACE_PEEKDATA: {
  99                         unsigned long tmp;
 100
 101                         ret = read_long(child, addr, &tmp);
 102                         if (ret < 0)
 103                                 break ;
 104                         ret = put_user(tmp, (unsigned long *) data);
 105                         break ;
 106                 }
 107
 108         /* read the word at location addr in the USER area. */
 109                 case PTRACE_PEEKUSR: {
 110                         unsigned long tmp = 0;
 111
 112                         if ((addr & 3) || addr < 0 || addr >= sizeof(struct user)) {
 113                                 ret = -EIO;
 114                                 break ;
 115                         }
 116
 117                         ret = 0;  /* Default return condition */
 118                         addr = addr >> 2; /* temporary hack. */
 119
 120                         if (addr < H8300_REGS_NO)
 121                                 tmp = h8300_get_reg(child, addr);
 122                         else {
 123                                 switch(addr) {
 124                                 case 49:
 125                                         tmp = child->mm->start_code;
 126                                         break ;
 127                                 case 50:
 128                                         tmp = child->mm->start_data;
 129                                         break ;
 130                                 case 51:
 131                                         tmp = child->mm->end_code;
 132                                         break ;
 133                                 case 52:
 134                                         tmp = child->mm->end_data;
 135                                         break ;
 136                                 default:
 137                                         ret = -EIO;
 138                                 }
 139                         }
 140                         if (!ret)
 141                                 ret = put_user(tmp,(unsigned long *) data);
 142                         break ;
 143                 }
 144
 145       /* when I and D space are separate, this will have to be fixed. */
 146                 case PTRACE_POKETEXT: /* write the word at location addr. */
 147                 case PTRACE_POKEDATA:
 148                         ret = 0;
 149                         if (access_process_vm(child, addr, &data, sizeof(data), 1) == sizeof(data))
 150                                 break;
 151                         ret = -EIO;
 152                         break;
 153
 154                 case PTRACE_POKEUSR: /* write the word at location addr in the USER area */
 155                         if ((addr & 3) || addr < 0 || addr >= sizeof(struct user)) {
 156                                 ret = -EIO;
 157                                 break ;
 158                         }
 159                         addr = addr >> 2; /* temporary hack. */
 160
 161                         if (addr == PT_ORIG_ER0) {
 162                                 ret = -EIO;
 163                                 break ;
 164                         }
 165                         if (addr < H8300_REGS_NO) {
 166                                 ret = h8300_put_reg(child, addr, data);
 167                                 break ;
 168                         }
 169                         ret = -EIO;
 170                         break ;
 171                 case PTRACE_SYSCALL: /* continue and stop at next (return from) syscall */
 172                 case PTRACE_CONT: { /* restart after signal. */
 173                         ret = -EIO;
 174                         if ((unsigned long) data >= _NSIG)
 175                                 break ;
 176                         if (request == PTRACE_SYSCALL)
 177                                 set_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
 178                         else
 179                                 clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
 180                         child->exit_code = data;
 181                         wake_up_process(child);
 182                         /* make sure the single step bit is not set. */
 183                         h8300_disable_trace(child);
 184                         ret = 0;
 185                 }
 186
 187 /*
 188  * make the child exit.  Best I can do is send it a sigkill.
 189  * perhaps it should be put in the status that it wants to
 190  * exit.
 191  */
 192                 case PTRACE_KILL: {
 193
 194                         ret = 0;
 195                         if (child->exit_state == EXIT_ZOMBIE) /* already dead */
 196                                 break;
 197                         child->exit_code = SIGKILL;
 198                         h8300_disable_trace(child);
 199                         wake_up_process(child);
 200                         break;
 201                 }
 202
 203                 case PTRACE_SINGLESTEP: {  /* set the trap flag. */
 204                         ret = -EIO;
 205                         if ((unsigned long) data > _NSIG)
 206                                 break;
 207                         clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
 208                         child->exit_code = data;
 209                         h8300_enable_trace(child);
 210                         wake_up_process(child);
 211                         ret = 0;
 212                         break;
 213                 }
 214
 215                 case PTRACE_DETACH:     /* detach a process that was attached. */
 216                         ret = ptrace_detach(child, data);
 217                         break;
 218
 219                 case PTRACE_GETREGS: { /* Get all gp regs from the child. */
 220                         int i;
 221                         unsigned long tmp;
 222                         for (i = 0; i < H8300_REGS_NO; i++) {
 223                             tmp = h8300_get_reg(child, i);
 224                             if (put_user(tmp, (unsigned long *) data)) {
 225                                 ret = -EFAULT;
 226                                 break;
 227                             }
 228                             data += sizeof(long);
 229                         }
 230                         ret = 0;
 231                         break;
 232                 }
 233
 234                 case PTRACE_SETREGS: { /* Set all gp regs in the child. */
 235                         int i;
 236                         unsigned long tmp;
 237                         for (i = 0; i < H8300_REGS_NO; i++) {
 238                             if (get_user(tmp, (unsigned long *) data)) {
 239                                 ret = -EFAULT;
 240                                 break;
 241                             }
 242                             h8300_put_reg(child, i, tmp);
 243                             data += sizeof(long);
 244                         }
 245                         ret = 0;
 246                         break;
 247                 }
 248
 249                 default:
 250                         ret = -EIO;
 251                         break;
 252         }
 253 out_tsk:
 254         put_task_struct(child);
 255 out:
 256         unlock_kernel();
 257         return ret;
 258 }
 259
 260 asmlinkage void syscall_trace(void)
 261 {
 262         if (!test_thread_flag(TIF_SYSCALL_TRACE))
 263                 return;
 264         if (!(current->ptrace & PT_PTRACED))
 265                 return;
 266         ptrace_notify(SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD)
 267                                  ? 0x80 : 0));
 268         /*
 269          * this isn't the same as continuing with a signal, but it will do
 270          * for normal use.  strace only continues with a signal if the
 271          * stopping signal is not SIGTRAP.  -brl
 272          */
 273         if (current->exit_code) {
 274                 send_sig(current->exit_code, current, 1);
 275                 current->exit_code = 0;
 276         }
 277 }