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 "ptrace_user.h"
  11 /* Grr, asm/user.h includes asm/ptrace.h, so has to follow ptrace_user.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         if (ptrace(PTRACE_GETREGS, pid, 0, regs_out) < 0)
  21                 return -errno;
  22         return 0;
  23 }
  24
  25 int ptrace_setregs(long pid, unsigned long *regs)
  26 {
  27         if (ptrace(PTRACE_SETREGS, pid, 0, regs) < 0)
  28                 return -errno;
  29         return 0;
  30 }
  31
  32 int ptrace_getfpregs(long pid, unsigned long *regs)
  33 {
  34         if (ptrace(PTRACE_GETFPREGS, pid, 0, regs) < 0)
  35                 return -errno;
  36         return 0;
  37 }
  38
  39 int ptrace_setfpregs(long pid, unsigned long *regs)
  40 {
  41         if (ptrace(PTRACE_SETFPREGS, pid, 0, regs) < 0)
  42                 return -errno;
  43         return 0;
  44 }
  45
  46 static void write_debugregs(int pid, unsigned long *regs)
  47 {
  48         struct user *dummy;
  49         int nregs, i;
  50
  51         dummy = NULL;
  52         nregs = sizeof(dummy->u_debugreg)/sizeof(dummy->u_debugreg[0]);
  53         for(i = 0; i < nregs; i++){
  54                 if((i == 4) || (i == 5)) continue;
  55                 if(ptrace(PTRACE_POKEUSR, pid, &dummy->u_debugreg[i],
  56                           regs[i]) < 0)
  57                         printk("write_debugregs - ptrace failed on "
  58                                "register %d, value = 0x%x, errno = %d\n", i,
  59                                regs[i], errno);
  60         }
  61 }
  62
  63 static void read_debugregs(int pid, unsigned long *regs)
  64 {
  65         struct user *dummy;
  66         int nregs, i;
  67
  68         dummy = NULL;
  69         nregs = sizeof(dummy->u_debugreg)/sizeof(dummy->u_debugreg[0]);
  70         for(i = 0; i < nregs; i++){
  71                 regs[i] = ptrace(PTRACE_PEEKUSR, pid,
  72                                  &dummy->u_debugreg[i], 0);
  73         }
  74 }
  75
  76 /* Accessed only by the tracing thread */
  77 static unsigned long kernel_debugregs[8] = { [ 0 ... 7 ] = 0 };
  78 static int debugregs_seq = 0;
  79
  80 void arch_enter_kernel(void *task, int pid)
  81 {
  82         read_debugregs(pid, TASK_DEBUGREGS(task));
  83         write_debugregs(pid, kernel_debugregs);
  84 }
  85
  86 void arch_leave_kernel(void *task, int pid)
  87 {
  88         read_debugregs(pid, kernel_debugregs);
  89         write_debugregs(pid, TASK_DEBUGREGS(task));
  90 }
  91
  92 void ptrace_pokeuser(unsigned long addr, unsigned long data)
  93 {
  94         if((addr < offsetof(struct user, u_debugreg[0])) ||
  95            (addr > offsetof(struct user, u_debugreg[7])))
  96                 return;
  97         addr -= offsetof(struct user, u_debugreg[0]);
  98         addr = addr >> 2;
  99         if(kernel_debugregs[addr] == data) return;
 100
 101         kernel_debugregs[addr] = data;
 102         debugregs_seq++;
 103 }
 104
 105 static void update_debugregs_cb(void *arg)
 106 {
 107         int pid = *((int *) arg);
 108
 109         write_debugregs(pid, kernel_debugregs);
 110 }
 111
 112 void update_debugregs(int seq)
 113 {
 114         int me;
 115
 116         if(seq == debugregs_seq) return;
 117
 118         me = os_getpid();
 119         initial_thread_cb(update_debugregs_cb, &me);
 120 }
 121
 122 /*
 123  * Overrides for Emacs so that we follow Linus's tabbing style.
 124  * Emacs will notice this stuff at the end of the file and automatically
 125  * adjust the settings for this buffer only.  This must remain at the end
 126  * of the file.
 127  * ---------------------------------------------------------------------------
 128  * Local variables:
 129  * c-file-style: "linux"
 130  * End:
 131  */