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 #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 /* All the below stuff is of interest for TT mode only */
  48 static void write_debugregs(int pid, unsigned long *regs)
  49 {
  50         struct user *dummy;
  51         int nregs, i;
  52
  53         dummy = NULL;
  54         nregs = sizeof(dummy->u_debugreg)/sizeof(dummy->u_debugreg[0]);
  55         for(i = 0; i < nregs; i++){
  56                 if((i == 4) || (i == 5)) continue;
  57                 if(ptrace(PTRACE_POKEUSR, pid, &dummy->u_debugreg[i],
  58                           regs[i]) < 0)
  59                         printk("write_debugregs - ptrace failed on "
  60                                "register %d, value = 0x%lx, errno = %d\n", i,
  61                                regs[i], errno);
  62         }
  63 }
  64
  65 static void read_debugregs(int pid, unsigned long *regs)
  66 {
  67         struct user *dummy;
  68         int nregs, i;
  69
  70         dummy = NULL;
  71         nregs = sizeof(dummy->u_debugreg)/sizeof(dummy->u_debugreg[0]);
  72         for(i = 0; i < nregs; i++){
  73                 regs[i] = ptrace(PTRACE_PEEKUSR, pid,
  74                                  &dummy->u_debugreg[i], 0);
  75         }
  76 }
  77
  78 /* Accessed only by the tracing thread */
  79 static unsigned long kernel_debugregs[8] = { [ 0 ... 7 ] = 0 };
  80
  81 void arch_enter_kernel(void *task, int pid)
  82 {
  83         read_debugregs(pid, TASK_DEBUGREGS(task));
  84         write_debugregs(pid, kernel_debugregs);
  85 }
  86
  87 void arch_leave_kernel(void *task, int pid)
  88 {
  89         read_debugregs(pid, kernel_debugregs);
  90         write_debugregs(pid, TASK_DEBUGREGS(task));
  91 }
  92
  93 #ifdef UML_CONFIG_PT_PROXY
  94 /* Accessed only by the tracing thread */
  95 static int debugregs_seq;
  96
  97 /* Only called by the ptrace proxy */
  98 void ptrace_pokeuser(unsigned long addr, unsigned long data)
  99 {
 100         if((addr < offsetof(struct user, u_debugreg[0])) ||
 101            (addr > offsetof(struct user, u_debugreg[7])))
 102                 return;
 103         addr -= offsetof(struct user, u_debugreg[0]);
 104         addr = addr >> 2;
 105         if(kernel_debugregs[addr] == data) return;
 106
 107         kernel_debugregs[addr] = data;
 108         debugregs_seq++;
 109 }
 110
 111 static void update_debugregs_cb(void *arg)
 112 {
 113         int pid = *((int *) arg);
 114
 115         write_debugregs(pid, kernel_debugregs);
 116 }
 117
 118 /* Optimized out in its header when not defined */
 119 void update_debugregs(int seq)
 120 {
 121         int me;
 122
 123         if(seq == debugregs_seq) return;
 124
 125         me = os_getpid();
 126         initial_thread_cb(update_debugregs_cb, &me);
 127 }
 128 #endif
 129
 130 /*
 131  * Overrides for Emacs so that we follow Linus's tabbing style.
 132  * Emacs will notice this stuff at the end of the file and automatically
 133  * adjust the settings for this buffer only.  This must remain at the end
 134  * of the file.
 135  * ---------------------------------------------------------------------------
 136  * Local variables:
 137  * c-file-style: "linux"
 138  * End:
 139  */