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