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 <stddef.h>
   8 #include <errno.h>
   9 #include <unistd.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 #include "uml-config.h"
  18
  19 int ptrace_getregs(long pid, unsigned long *regs_out)
  20 {
  21         if (ptrace(PTRACE_GETREGS, pid, 0, regs_out) < 0)
  22                 return -errno;
  23         return 0;
  24 }
  25
  26 int ptrace_setregs(long pid, unsigned long *regs)
  27 {
  28         if (ptrace(PTRACE_SETREGS, pid, 0, regs) < 0)
  29                 return -errno;
  30         return 0;
  31 }
  32
  33 int ptrace_getfpregs(long pid, unsigned long *regs)
  34 {
  35         if (ptrace(PTRACE_GETFPREGS, pid, 0, regs) < 0)
  36                 return -errno;
  37         return 0;
  38 }
  39
  40 int ptrace_setfpregs(long pid, unsigned long *regs)
  41 {
  42         if (ptrace(PTRACE_SETFPREGS, pid, 0, regs) < 0)
  43                 return -errno;
  44         return 0;
  45 }
  46
  47 #ifdef UML_CONFIG_MODE_TT
  48
  49 static void write_debugregs(int pid, unsigned long *regs)
  50 {
  51         struct user *dummy;
  52         int nregs, i;
  53
  54         dummy = NULL;
  55         nregs = ARRAY_SIZE(dummy->u_debugreg);
  56         for(i = 0; i < nregs; i++){
  57                 if((i == 4) || (i == 5)) continue;
  58                 if(ptrace(PTRACE_POKEUSR, pid, &dummy->u_debugreg[i],
  59                           regs[i]) < 0)
  60                         printk("write_debugregs - ptrace failed on "
  61                                "register %d, value = 0x%lx, errno = %d\n", i,
  62                                regs[i], errno);
  63         }
  64 }
  65
  66 static void read_debugregs(int pid, unsigned long *regs)
  67 {
  68         struct user *dummy;
  69         int nregs, i;
  70
  71         dummy = NULL;
  72         nregs = ARRAY_SIZE(dummy->u_debugreg);
  73         for(i = 0; i < nregs; i++){
  74                 regs[i] = ptrace(PTRACE_PEEKUSR, pid,
  75                                  &dummy->u_debugreg[i], 0);
  76         }
  77 }
  78
  79 /* Accessed only by the tracing thread */
  80 static unsigned long kernel_debugregs[8] = { [ 0 ... 7 ] = 0 };
  81
  82 void arch_enter_kernel(void *task, int pid)
  83 {
  84         read_debugregs(pid, TASK_DEBUGREGS(task));
  85         write_debugregs(pid, kernel_debugregs);
  86 }
  87
  88 void arch_leave_kernel(void *task, int pid)
  89 {
  90         read_debugregs(pid, kernel_debugregs);
  91         write_debugregs(pid, TASK_DEBUGREGS(task));
  92 }
  93
  94 #ifdef UML_CONFIG_PT_PROXY
  95 /* Accessed only by the tracing thread */
  96 static int debugregs_seq;
  97
  98 /* Only called by the ptrace proxy */
  99 void ptrace_pokeuser(unsigned long addr, unsigned long data)
 100 {
 101         if((addr < offsetof(struct user, u_debugreg[0])) ||
 102            (addr > offsetof(struct user, u_debugreg[7])))
 103                 return;
 104         addr -= offsetof(struct user, u_debugreg[0]);
 105         addr = addr >> 2;
 106         if(kernel_debugregs[addr] == data) return;
 107
 108         kernel_debugregs[addr] = data;
 109         debugregs_seq++;
 110 }
 111
 112 static void update_debugregs_cb(void *arg)
 113 {
 114         int pid = *((int *) arg);
 115
 116         write_debugregs(pid, kernel_debugregs);
 117 }
 118
 119 /* Optimized out in its header when not defined */
 120 void update_debugregs(int seq)
 121 {
 122         int me;
 123
 124         if(seq == debugregs_seq) return;
 125
 126         me = os_getpid();
 127         initial_thread_cb(update_debugregs_cb, &me);
 128 }
 129 #endif
 130
 131 #endif