arch/h8300/kernel/ptrace_s.c

   1 /*
   2  *  linux/arch/h8300/platform/h8s/ptrace_h8s.c
   3  *    ptrace cpu depend helper functions
   4  *
   5  *  Yoshinori Sato <ysato@users.sourceforge.jp>
   6  *
   7  * This file is subject to the terms and conditions of the GNU General
   8  * Public License.  See the file COPYING in the main directory of
   9  * this archive for more details.
  10  */
  11
  12 #include <linux/linkage.h>
  13 #include <linux/sched.h>
  14 #include <linux/errno.h>
  15 #include <asm/ptrace.h>
  16
  17 #define CCR_MASK  0x6f
  18 #define EXR_TRACE 0x80
  19
  20 /* Mapping from PT_xxx to the stack offset at which the register is
  21    saved.  Notice that usp has no stack-slot and needs to be treated
  22    specially (see get_reg/put_reg below). */
  23 static const int h8300_register_offset[] = {
  24         PT_REG(er1), PT_REG(er2), PT_REG(er3), PT_REG(er4),
  25         PT_REG(er5), PT_REG(er6), PT_REG(er0), PT_REG(orig_er0),
  26         PT_REG(ccr), PT_REG(pc),  0,           PT_REG(exr)
  27 };
  28
  29 /* read register */
  30 long h8300_get_reg(struct task_struct *task, int regno)
  31 {
  32         switch (regno) {
  33         case PT_USP:
  34                 return task->thread.usp + sizeof(long)*2 + 2;
  35         case PT_CCR:
  36         case PT_EXR:
  37             return *(unsigned short *)(task->thread.esp0 +
  38                                        h8300_register_offset[regno]);
  39         default:
  40             return *(unsigned long *)(task->thread.esp0 +
  41                                       h8300_register_offset[regno]);
  42         }
  43 }
  44
  45 /* write register */
  46 int h8300_put_reg(struct task_struct *task, int regno, unsigned long data)
  47 {
  48         unsigned short oldccr;
  49         switch (regno) {
  50         case PT_USP:
  51                 task->thread.usp = data - sizeof(long)*2 - 2;
  52         case PT_CCR:
  53                 oldccr = *(unsigned short *)(task->thread.esp0 +
  54                                              h8300_register_offset[regno]);
  55                 oldccr &= ~CCR_MASK;
  56                 data &= CCR_MASK;
  57                 data |= oldccr;
  58                 *(unsigned short *)(task->thread.esp0 +
  59                                     h8300_register_offset[regno]) = data;
  60                 break;
  61         case PT_EXR:
  62                 /* exr modify not support */
  63                 return -EIO;
  64         default:
  65                 *(unsigned long *)(task->thread.esp0 +
  66                                    h8300_register_offset[regno]) = data;
  67                 break;
  68         }
  69         return 0;
  70 }
  71
  72 /* disable singlestep */
  73 void user_disable_single_step(struct task_struct *child)
  74 {
  75         *(unsigned short *)(child->thread.esp0 +
  76                             h8300_register_offset[PT_EXR]) &= ~EXR_TRACE;
  77 }
  78
  79 /* enable singlestep */
  80 void user_enable_single_step(struct task_struct *child)
  81 {
  82         *(unsigned short *)(child->thread.esp0 +
  83                             h8300_register_offset[PT_EXR]) |= EXR_TRACE;
  84 }
  85
  86 asmlinkage void trace_trap(unsigned long bp)
  87 {
  88         (void)bp;
  89         force_sig(SIGTRAP, current);
  90 }