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 #include <linux/signal.h>
  28
  29 #include <asm/uaccess.h>
  30 #include <asm/page.h>
  31 #include <asm/pgtable.h>
  32 #include <asm/system.h>
  33 #include <asm/processor.h>
  34 #include <asm/signal.h>
  35
  36 /* cpu depend functions */
  37 extern long h8300_get_reg(struct task_struct *task, int regno);
  38 extern int  h8300_put_reg(struct task_struct *task, int regno, unsigned long data);
  39 extern void h8300_disable_trace(struct task_struct *child);
  40 extern void h8300_enable_trace(struct task_struct *child);
  41
  42 /*
  43  * does not yet catch signals sent when the child dies.
  44  * in exit.c or in signal.c.
  45  */
  46
  47 inline
  48 static int read_long(struct task_struct * tsk, unsigned long addr,
  49         unsigned long * result)
  50 {
  51         *result = *(unsigned long *)addr;
  52         return 0;
  53 }
  54
  55 void ptrace_disable(struct task_struct *child)
  56 {
  57         h8300_disable_trace(child);
  58 }
  59
  60 asmlinkage int sys_ptrace(long request, long pid, long addr, long data)
  61 {
  62         struct task_struct *child;
  63         int ret;
  64
  65         lock_kernel();
  66         ret = -EPERM;
  67         if (request == PTRACE_TRACEME) {
  68                 /* are we already being traced? */
  69                 if (current->ptrace & PT_PTRACED)
  70                         goto out;
  71                 /* set the ptrace bit in the process flags. */
  72                 current->ptrace |= PT_PTRACED;
  73                 ret = 0;
  74                 goto out;
  75         }
  76         ret = -ESRCH;
  77         read_lock(&tasklist_lock);
  78         child = find_task_by_pid(pid);
  79         if (child)
  80                 get_task_struct(child);
  81         read_unlock(&tasklist_lock);
  82         if (!child)
  83                 goto out;
  84
  85         ret = -EPERM;
  86         if (pid == 1)           /* you may not mess with init */
  87                 goto out_tsk;
  88
  89         if (request == PTRACE_ATTACH) {
  90                 ret = ptrace_attach(child);
  91                 goto out_tsk;
  92         }
  93         ret = ptrace_check_attach(child, request == PTRACE_KILL);
  94         if (ret < 0)
  95                 goto out_tsk;
  96
  97         switch (request) {
  98                 case PTRACE_PEEKTEXT: /* read word at location addr. */
  99                 case PTRACE_PEEKDATA: {
 100                         unsigned long tmp;
 101
 102                         ret = read_long(child, addr, &tmp);
 103                         if (ret < 0)
 104                                 break ;
 105                         ret = put_user(tmp, (unsigned long *) data);
 106                         break ;
 107                 }
 108
 109         /* read the word at location addr in the USER area. */
 110                 case PTRACE_PEEKUSR: {
 111                         unsigned long tmp = 0;
 112
 113                         if ((addr & 3) || addr < 0 || addr >= sizeof(struct user)) {
 114                                 ret = -EIO;
 115                                 break ;
 116                         }
 117
 118                         ret = 0;  /* Default return condition */
 119                         addr = addr >> 2; /* temporary hack. */
 120
 121                         if (addr < H8300_REGS_NO)
 122                                 tmp = h8300_get_reg(child, addr);
 123                         else {
 124                                 switch(addr) {
 125                                 case 49:
 126                                         tmp = child->mm->start_code;
 127                                         break ;
 128                                 case 50:
 129                                         tmp = child->mm->start_data;
 130                                         break ;
 131                                 case 51:
 132                                         tmp = child->mm->end_code;
 133                                         break ;
 134                                 case 52:
 135                                         tmp = child->mm->end_data;
 136                                         break ;
 137                                 default:
 138                                         ret = -EIO;
 139                                 }
 140                         }
 141                         if (!ret)
 142                                 ret = put_user(tmp,(unsigned long *) data);
 143                         break ;
 144                 }
 145
 146       /* when I and D space are separate, this will have to be fixed. */
 147                 case PTRACE_POKETEXT: /* write the word at location addr. */
 148                 case PTRACE_POKEDATA:
 149                         ret = 0;
 150                         if (access_process_vm(child, addr, &data, sizeof(data), 1) == sizeof(data))
 151                                 break;
 152                         ret = -EIO;
 153                         break;
 154
 155                 case PTRACE_POKEUSR: /* write the word at location addr in the USER area */
 156                         if ((addr & 3) || addr < 0 || addr >= sizeof(struct user)) {
 157                                 ret = -EIO;
 158                                 break ;
 159                         }
 160                         addr = addr >> 2; /* temporary hack. */
 161
 162                         if (addr == PT_ORIG_ER0) {
 163                                 ret = -EIO;
 164                                 break ;
 165                         }
 166                         if (addr < H8300_REGS_NO) {
 167                                 ret = h8300_put_reg(child, addr, data);
 168                                 break ;
 169                         }
 170                         ret = -EIO;
 171                         break ;
 172                 case PTRACE_SYSCALL: /* continue and stop at next (return from) syscall */
 173                 case PTRACE_CONT: { /* restart after signal. */
 174                         ret = -EIO;
 175                         if (!valid_signal(data))
 176                                 break ;
 177                         if (request == PTRACE_SYSCALL)
 178                                 set_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
 179                         else
 180                                 clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
 181                         child->exit_code = data;
 182                         wake_up_process(child);
 183                         /* make sure the single step bit is not set. */
 184                         h8300_disable_trace(child);
 185                         ret = 0;
 186                 }
 187
 188 /*
 189  * make the child exit.  Best I can do is send it a sigkill.
 190  * perhaps it should be put in the status that it wants to
 191  * exit.
 192  */
 193                 case PTRACE_KILL: {
 194
 195                         ret = 0;
 196                         if (child->exit_state == EXIT_ZOMBIE) /* already dead */
 197                                 break;
 198                         child->exit_code = SIGKILL;
 199                         h8300_disable_trace(child);
 200                         wake_up_process(child);
 201                         break;
 202                 }
 203
 204                 case PTRACE_SINGLESTEP: {  /* set the trap flag. */
 205                         ret = -EIO;
 206                         if (!valid_signal(data))
 207                                 break;
 208                         clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
 209                         child->exit_code = data;
 210                         h8300_enable_trace(child);
 211                         wake_up_process(child);
 212                         ret = 0;
 213                         break;
 214                 }
 215
 216                 case PTRACE_DETACH:     /* detach a process that was attached. */
 217                         ret = ptrace_detach(child, data);
 218                         break;
 219
 220                 case PTRACE_GETREGS: { /* Get all gp regs from the child. */
 221                         int i;
 222                         unsigned long tmp;
 223                         for (i = 0; i < H8300_REGS_NO; i++) {
 224                             tmp = h8300_get_reg(child, i);
 225                             if (put_user(tmp, (unsigned long *) data)) {
 226                                 ret = -EFAULT;
 227                                 break;
 228                             }
 229                             data += sizeof(long);
 230                         }
 231                         ret = 0;
 232                         break;
 233                 }
 234
 235                 case PTRACE_SETREGS: { /* Set all gp regs in the child. */
 236                         int i;
 237                         unsigned long tmp;
 238                         for (i = 0; i < H8300_REGS_NO; i++) {
 239                             if (get_user(tmp, (unsigned long *) data)) {
 240                                 ret = -EFAULT;
 241                                 break;
 242                             }
 243                             h8300_put_reg(child, i, tmp);
 244                             data += sizeof(long);
 245                         }
 246                         ret = 0;
 247                         break;
 248                 }
 249
 250                 default:
 251                         ret = -EIO;
 252                         break;
 253         }
 254 out_tsk:
 255         put_task_struct(child);
 256 out:
 257         unlock_kernel();
 258         return ret;
 259 }
 260
 261 asmlinkage void syscall_trace(void)
 262 {
 263         if (!test_thread_flag(TIF_SYSCALL_TRACE))
 264                 return;
 265         if (!(current->ptrace & PT_PTRACED))
 266                 return;
 267         ptrace_notify(SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD)
 268                                  ? 0x80 : 0));
 269         /*
 270          * this isn't the same as continuing with a signal, but it will do
 271          * for normal use.  strace only continues with a signal if the
 272          * stopping signal is not SIGTRAP.  -brl
 273          */
 274         if (current->exit_code) {
 275                 send_sig(current->exit_code, current, 1);
 276                 current->exit_code = 0;
 277         }
 278 }