arch/um/sys-i386/ptrace_user.c

   1 /*
   2  * Copyright (C) 2002 Jeff Dike (jdike@karaya.com)
   3  * Licensed under the GPL
   4  */
   5
   6 #include <stdio.h>
   7 #include <errno.h>
   8 #include <unistd.h>
   9 #include <linux/stddef.h>
  10 #include <sys/ptrace.h>
  11 #include <asm/ptrace.h>
  12 #include <asm/user.h>
  13 #include "kern_util.h"
  14 #include "sysdep/thread.h"
  15 #include "user.h"
  16 #include "os.h"
  17
  18 int ptrace_getregs(long pid, unsigned long *regs_out)
  19 {
  20         return(ptrace(PTRACE_GETREGS, pid, 0, regs_out));
  21 }
  22
  23 int ptrace_setregs(long pid, unsigned long *regs)
  24 {
  25         return(ptrace(PTRACE_SETREGS, pid, 0, regs));
  26 }
  27
  28 int ptrace_getfpregs(long pid, unsigned long *regs)
  29 {
  30         return(ptrace(PTRACE_GETFPREGS, pid, 0, regs));
  31 }
  32
  33 static void write_debugregs(int pid, unsigned long *regs)
  34 {
  35         struct user *dummy;
  36         int nregs, i;
  37
  38         dummy = NULL;
  39         nregs = sizeof(dummy->u_debugreg)/sizeof(dummy->u_debugreg[0]);
  40         for(i = 0; i < nregs; i++){
  41                 if((i == 4) || (i == 5)) continue;
  42                 if(ptrace(PTRACE_POKEUSER, pid, &dummy->u_debugreg[i],
  43                           regs[i]) < 0)
  44                         printk("write_debugregs - ptrace failed on "
  45                                "register %d, value = 0x%x, errno = %d\n", i,
  46                                regs[i], errno);
  47         }
  48 }
  49
  50 static void read_debugregs(int pid, unsigned long *regs)
  51 {
  52         struct user *dummy;
  53         int nregs, i;
  54
  55         dummy = NULL;
  56         nregs = sizeof(dummy->u_debugreg)/sizeof(dummy->u_debugreg[0]);
  57         for(i = 0; i < nregs; i++){
  58                 regs[i] = ptrace(PTRACE_PEEKUSER, pid,
  59                                  &dummy->u_debugreg[i], 0);
  60         }
  61 }
  62
  63 /* Accessed only by the tracing thread */
  64 static unsigned long kernel_debugregs[8] = { [ 0 ... 7 ] = 0 };
  65 static int debugregs_seq = 0;
  66
  67 void arch_enter_kernel(void *task, int pid)
  68 {
  69         read_debugregs(pid, TASK_DEBUGREGS(task));
  70         write_debugregs(pid, kernel_debugregs);
  71 }
  72
  73 void arch_leave_kernel(void *task, int pid)
  74 {
  75         read_debugregs(pid, kernel_debugregs);
  76         write_debugregs(pid, TASK_DEBUGREGS(task));
  77 }
  78
  79 void ptrace_pokeuser(unsigned long addr, unsigned long data)
  80 {
  81         if((addr < offsetof(struct user, u_debugreg[0])) ||
  82            (addr > offsetof(struct user, u_debugreg[7])))
  83                 return;
  84         addr -= offsetof(struct user, u_debugreg[0]);
  85         addr = addr >> 2;
  86         if(kernel_debugregs[addr] == data) return;
  87
  88         kernel_debugregs[addr] = data;
  89         debugregs_seq++;
  90 }
  91
  92 static void update_debugregs_cb(void *arg)
  93 {
  94         int pid = *((int *) arg);
  95
  96         write_debugregs(pid, kernel_debugregs);
  97 }
  98
  99 void update_debugregs(int seq)
 100 {
 101         int me;
 102
 103         if(seq == debugregs_seq) return;
 104
 105         me = os_getpid();
 106         initial_thread_cb(update_debugregs_cb, &me);
 107 }
 108
 109 /*
 110  * Overrides for Emacs so that we follow Linus's tabbing style.
 111  * Emacs will notice this stuff at the end of the file and automatically
 112  * adjust the settings for this buffer only.  This must remain at the end
 113  * of the file.
 114  * ---------------------------------------------------------------------------
 115  * Local variables:
 116  * c-file-style: "linux"
 117  * End:
 118  */