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