arch/um/sys-x86_64/ptrace.c

   1 /*
   2  * Copyright 2003 PathScale, Inc.
   3  *
   4  * Licensed under the GPL
   5  */
   6
   7 #define __FRAME_OFFSETS
   8 #include <asm/ptrace.h>
   9 #include <linux/sched.h>
  10 #include <linux/errno.h>
  11 #include <linux/mm.h>
  12 #include <asm/uaccess.h>
  13 #include <asm/elf.h>
  14
  15 /* XXX x86_64 */
  16 unsigned long not_ss;
  17 unsigned long not_ds;
  18 unsigned long not_es;
  19
  20 #define SC_SS(r) (not_ss)
  21 #define SC_DS(r) (not_ds)
  22 #define SC_ES(r) (not_es)
  23
  24 /* determines which flags the user has access to. */
  25 /* 1 = access 0 = no access */
  26 #define FLAG_MASK 0x44dd5UL
  27
  28 int putreg(struct task_struct *child, int regno, unsigned long value)
  29 {
  30         unsigned long tmp;
  31
  32 #ifdef TIF_IA32
  33         /* Some code in the 64bit emulation may not be 64bit clean.
  34            Don't take any chances. */
  35         if (test_tsk_thread_flag(child, TIF_IA32))
  36                 value &= 0xffffffff;
  37 #endif
  38         switch (regno){
  39         case FS:
  40         case GS:
  41         case DS:
  42         case ES:
  43         case SS:
  44         case CS:
  45                 if (value && (value & 3) != 3)
  46                         return -EIO;
  47                 value &= 0xffff;
  48                 break;
  49
  50         case FS_BASE:
  51         case GS_BASE:
  52                 if (!((value >> 48) == 0 || (value >> 48) == 0xffff))
  53                         return -EIO;
  54                 break;
  55
  56         case EFLAGS:
  57                 value &= FLAG_MASK;
  58                 tmp = PT_REGS_EFLAGS(&child->thread.regs) & ~FLAG_MASK;
  59                 value |= tmp;
  60                 break;
  61         }
  62
  63         PT_REGS_SET(&child->thread.regs, regno, value);
  64         return 0;
  65 }
  66
  67 int poke_user(struct task_struct *child, long addr, long data)
  68 {
  69         if ((addr & 3) || addr < 0)
  70                 return -EIO;
  71
  72         if (addr < MAX_REG_OFFSET)
  73                 return putreg(child, addr, data);
  74
  75 #if 0 /* Need x86_64 debugregs handling */
  76         else if((addr >= offsetof(struct user, u_debugreg[0])) &&
  77                 (addr <= offsetof(struct user, u_debugreg[7]))){
  78                 addr -= offsetof(struct user, u_debugreg[0]);
  79                 addr = addr >> 2;
  80                 if((addr == 4) || (addr == 5)) return -EIO;
  81                 child->thread.arch.debugregs[addr] = data;
  82                 return 0;
  83         }
  84 #endif
  85         return -EIO;
  86 }
  87
  88 unsigned long getreg(struct task_struct *child, int regno)
  89 {
  90         unsigned long retval = ~0UL;
  91         switch (regno) {
  92         case FS:
  93         case GS:
  94         case DS:
  95         case ES:
  96         case SS:
  97         case CS:
  98                 retval = 0xffff;
  99                 /* fall through */
 100         default:
 101                 retval &= PT_REG(&child->thread.regs, regno);
 102 #ifdef TIF_IA32
 103                 if (test_tsk_thread_flag(child, TIF_IA32))
 104                         retval &= 0xffffffff;
 105 #endif
 106         }
 107         return retval;
 108 }
 109
 110 int peek_user(struct task_struct *child, long addr, long data)
 111 {
 112         /* read the word at location addr in the USER area. */
 113         unsigned long tmp;
 114
 115         if ((addr & 3) || addr < 0)
 116                 return -EIO;
 117
 118         tmp = 0;  /* Default return condition */
 119         if(addr < MAX_REG_OFFSET){
 120                 tmp = getreg(child, addr);
 121         }
 122 #if 0 /* Need x86_64 debugregs handling */
 123         else if((addr >= offsetof(struct user, u_debugreg[0])) &&
 124                 (addr <= offsetof(struct user, u_debugreg[7]))){
 125                 addr -= offsetof(struct user, u_debugreg[0]);
 126                 addr = addr >> 2;
 127                 tmp = child->thread.arch.debugregs[addr];
 128         }
 129 #endif
 130         return put_user(tmp, (unsigned long *) data);
 131 }
 132
 133 void arch_switch(void)
 134 {
 135 /* XXX
 136         printk("arch_switch\n");
 137 */
 138 }
 139
 140 /* XXX Mostly copied from sys-i386 */
 141 int is_syscall(unsigned long addr)
 142 {
 143         unsigned short instr;
 144         int n;
 145
 146         n = copy_from_user(&instr, (void __user *) addr, sizeof(instr));
 147         if(n){
 148                 /* access_process_vm() grants access to vsyscall and stub,
 149                  * while copy_from_user doesn't. Maybe access_process_vm is
 150                  * slow, but that doesn't matter, since it will be called only
 151                  * in case of singlestepping, if copy_from_user failed.
 152                  */
 153                 n = access_process_vm(current, addr, &instr, sizeof(instr), 0);
 154                 if(n != sizeof(instr)) {
 155                         printk("is_syscall : failed to read instruction from "
 156                                "0x%lx\n", addr);
 157                         return(1);
 158                 }
 159         }
 160         /* sysenter */
 161         return(instr == 0x050f);
 162 }
 163
 164 int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpu )
 165 {
 166         panic("dump_fpu");
 167         return(1);
 168 }
 169
 170 int get_fpregs(unsigned long buf, struct task_struct *child)
 171 {
 172         panic("get_fpregs");
 173         return(0);
 174 }
 175
 176 int set_fpregs(unsigned long buf, struct task_struct *child)
 177 {
 178         panic("set_fpregs");
 179         return(0);
 180 }
 181
 182 int get_fpxregs(unsigned long buf, struct task_struct *tsk)
 183 {
 184         panic("get_fpxregs");
 185         return(0);
 186 }
 187
 188 int set_fpxregs(unsigned long buf, struct task_struct *tsk)
 189 {
 190         panic("set_fxpregs");
 191         return(0);
 192 }
 193
 194 /*
 195  * Overrides for Emacs so that we follow Linus's tabbing style.
 196  * Emacs will notice this stuff at the end of the file and automatically
 197  * adjust the settings for this buffer only.  This must remain at the end
 198  * of the file.
 199  * ---------------------------------------------------------------------------
 200  * Local variables:
 201  * c-file-style: "linux"
 202  * End:
 203  */