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         if (!vx_check(vx_task_xid(child), VX_WATCH|VX_IDENT))
  85                 goto out_tsk;
  86
  87         ret = -EPERM;
  88         if (pid == 1)           /* you may not mess with init */
  89                 goto out_tsk;
  90
  91         if (request == PTRACE_ATTACH) {
  92                 ret = ptrace_attach(child);
  93                 goto out_tsk;
  94         }
  95         ret = ptrace_check_attach(child, request == PTRACE_KILL);
  96         if (ret < 0)
  97                 goto out_tsk;
  98
  99         switch (request) {
 100                 case PTRACE_PEEKTEXT: /* read word at location addr. */
 101                 case PTRACE_PEEKDATA: {
 102                         unsigned long tmp;
 103
 104                         ret = read_long(child, addr, &tmp);
 105                         if (ret < 0)
 106                                 break ;
 107                         ret = put_user(tmp, (unsigned long *) data);
 108                         break ;
 109                 }
 110
 111         /* read the word at location addr in the USER area. */
 112                 case PTRACE_PEEKUSR: {
 113                         unsigned long tmp = 0;
 114
 115                         if ((addr & 3) || addr < 0 || addr >= sizeof(struct user)) {
 116                                 ret = -EIO;
 117                                 break ;
 118                         }
 119
 120                         ret = 0;  /* Default return condition */
 121                         addr = addr >> 2; /* temporary hack. */
 122
 123                         if (addr < H8300_REGS_NO)
 124                                 tmp = h8300_get_reg(child, addr);
 125                         else {
 126                                 switch(addr) {
 127                                 case 49:
 128                                         tmp = child->mm->start_code;
 129                                         break ;
 130                                 case 50:
 131                                         tmp = child->mm->start_data;
 132                                         break ;
 133                                 case 51:
 134                                         tmp = child->mm->end_code;
 135                                         break ;
 136                                 case 52:
 137                                         tmp = child->mm->end_data;
 138                                         break ;
 139                                 default:
 140                                         ret = -EIO;
 141                                 }
 142                         }
 143                         if (!ret)
 144                                 ret = put_user(tmp,(unsigned long *) data);
 145                         break ;
 146                 }
 147
 148       /* when I and D space are separate, this will have to be fixed. */
 149                 case PTRACE_POKETEXT: /* write the word at location addr. */
 150                 case PTRACE_POKEDATA:
 151                         ret = 0;
 152                         if (access_process_vm(child, addr, &data, sizeof(data), 1) == sizeof(data))
 153                                 break;
 154                         ret = -EIO;
 155                         break;
 156
 157                 case PTRACE_POKEUSR: /* write the word at location addr in the USER area */
 158                         if ((addr & 3) || addr < 0 || addr >= sizeof(struct user)) {
 159                                 ret = -EIO;
 160                                 break ;
 161                         }
 162                         addr = addr >> 2; /* temporary hack. */
 163
 164                         if (addr == PT_ORIG_ER0) {
 165                                 ret = -EIO;
 166                                 break ;
 167                         }
 168                         if (addr < H8300_REGS_NO) {
 169                                 ret = h8300_put_reg(child, addr, data);
 170                                 break ;
 171                         }
 172                         ret = -EIO;
 173                         break ;
 174                 case PTRACE_SYSCALL: /* continue and stop at next (return from) syscall */
 175                 case PTRACE_CONT: { /* restart after signal. */
 176                         ret = -EIO;
 177                         if (!valid_signal(data))
 178                                 break ;
 179                         if (request == PTRACE_SYSCALL)
 180                                 set_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
 181                         else
 182                                 clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
 183                         child->exit_code = data;
 184                         wake_up_process(child);
 185                         /* make sure the single step bit is not set. */
 186                         h8300_disable_trace(child);
 187                         ret = 0;
 188                 }
 189
 190 /*
 191  * make the child exit.  Best I can do is send it a sigkill.
 192  * perhaps it should be put in the status that it wants to
 193  * exit.
 194  */
 195                 case PTRACE_KILL: {
 196
 197                         ret = 0;
 198                         if (child->exit_state == EXIT_ZOMBIE) /* already dead */
 199                                 break;
 200                         child->exit_code = SIGKILL;
 201                         h8300_disable_trace(child);
 202                         wake_up_process(child);
 203                         break;
 204                 }
 205
 206                 case PTRACE_SINGLESTEP: {  /* set the trap flag. */
 207                         ret = -EIO;
 208                         if (!valid_signal(data))
 209                                 break;
 210                         clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
 211                         child->exit_code = data;
 212                         h8300_enable_trace(child);
 213                         wake_up_process(child);
 214                         ret = 0;
 215                         break;
 216                 }
 217
 218                 case PTRACE_DETACH:     /* detach a process that was attached. */
 219                         ret = ptrace_detach(child, data);
 220                         break;
 221
 222                 case PTRACE_GETREGS: { /* Get all gp regs from the child. */
 223                         int i;
 224                         unsigned long tmp;
 225                         for (i = 0; i < H8300_REGS_NO; i++) {
 226                             tmp = h8300_get_reg(child, i);
 227                             if (put_user(tmp, (unsigned long *) data)) {
 228                                 ret = -EFAULT;
 229                                 break;
 230                             }
 231                             data += sizeof(long);
 232                         }
 233                         ret = 0;
 234                         break;
 235                 }
 236
 237                 case PTRACE_SETREGS: { /* Set all gp regs in the child. */
 238                         int i;
 239                         unsigned long tmp;
 240                         for (i = 0; i < H8300_REGS_NO; i++) {
 241                             if (get_user(tmp, (unsigned long *) data)) {
 242                                 ret = -EFAULT;
 243                                 break;
 244                             }
 245                             h8300_put_reg(child, i, tmp);
 246                             data += sizeof(long);
 247                         }
 248                         ret = 0;
 249                         break;
 250                 }
 251
 252                 default:
 253                         ret = -EIO;
 254                         break;
 255         }
 256 out_tsk:
 257         put_task_struct(child);
 258 out:
 259         unlock_kernel();
 260         return ret;
 261 }
 262
 263 asmlinkage void syscall_trace(void)
 264 {
 265         if (!test_thread_flag(TIF_SYSCALL_TRACE))
 266                 return;
 267         if (!(current->ptrace & PT_PTRACED))
 268                 return;
 269         ptrace_notify(SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD)
 270                                  ? 0x80 : 0));
 271         /*
 272          * this isn't the same as continuing with a signal, but it will do
 273          * for normal use.  strace only continues with a signal if the
 274          * stopping signal is not SIGTRAP.  -brl
 275          */
 276         if (current->exit_code) {
 277                 send_sig(current->exit_code, current, 1);
 278                 current->exit_code = 0;
 279         }
 280 }