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
19int 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
26int 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
33int 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
40int 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
49static 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
66static 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 */
80static unsigned long kernel_debugregs[8] = { [ 0 ... 7 ] = 0 };
81
82void arch_enter_kernel(void *task, int pid)
83{
84	read_debugregs(pid, TASK_DEBUGREGS(task));
85	write_debugregs(pid, kernel_debugregs);
86}
87
88void 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 */
96static int debugregs_seq;
97
98/* Only called by the ptrace proxy */
99void 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
112static 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 */
120void 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
132