summaryrefslogtreecommitdiffstats
path: root/arch/um/sys-i386/ptrace_user.c
blob: 9f3bd8ed78f5b2d7cc47380227051327aad98e3b (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
/* 
 * Copyright (C) 2002 Jeff Dike (jdike@karaya.com)
 * Licensed under the GPL
 */

#include <stdio.h>
#include <errno.h>
#include <unistd.h>
#include <linux/stddef.h>
#include "ptrace_user.h"
/* Grr, asm/user.h includes asm/ptrace.h, so has to follow ptrace_user.h */
#include <asm/user.h>
#include "kern_util.h"
#include "sysdep/thread.h"
#include "user.h"
#include "os.h"
#include "uml-config.h"

int ptrace_getregs(long pid, unsigned long *regs_out)
{
	if (ptrace(PTRACE_GETREGS, pid, 0, regs_out) < 0)
		return -errno;
	return 0;
}

int ptrace_setregs(long pid, unsigned long *regs)
{
	if (ptrace(PTRACE_SETREGS, pid, 0, regs) < 0)
		return -errno;
	return 0;
}

int ptrace_getfpregs(long pid, unsigned long *regs)
{
	if (ptrace(PTRACE_GETFPREGS, pid, 0, regs) < 0)
		return -errno;
	return 0;
}

int ptrace_setfpregs(long pid, unsigned long *regs)
{
	if (ptrace(PTRACE_SETFPREGS, pid, 0, regs) < 0)
		return -errno;
	return 0;
}

/* All the below stuff is of interest for TT mode only */
static void write_debugregs(int pid, unsigned long *regs)
{
	struct user *dummy;
	int nregs, i;

	dummy = NULL;
	nregs = sizeof(dummy->u_debugreg)/sizeof(dummy->u_debugreg[0]);
	for(i = 0; i < nregs; i++){
		if((i == 4) || (i == 5)) continue;
		if(ptrace(PTRACE_POKEUSR, pid, &dummy->u_debugreg[i],
			  regs[i]) < 0)
			printk("write_debugregs - ptrace failed on "
			       "register %d, value = 0x%x, errno = %d\n", i,
			       regs[i], errno);
	}
}

static void read_debugregs(int pid, unsigned long *regs)
{
	struct user *dummy;
	int nregs, i;

	dummy = NULL;
	nregs = sizeof(dummy->u_debugreg)/sizeof(dummy->u_debugreg[0]);
	for(i = 0; i < nregs; i++){
		regs[i] = ptrace(PTRACE_PEEKUSR, pid,
				 &dummy->u_debugreg[i], 0);
	}
}

/* Accessed only by the tracing thread */
static unsigned long kernel_debugregs[8] = { [ 0 ... 7 ] = 0 };

void arch_enter_kernel(void *task, int pid)
{
	read_debugregs(pid, TASK_DEBUGREGS(task));
	write_debugregs(pid, kernel_debugregs);
}

void arch_leave_kernel(void *task, int pid)
{
	read_debugregs(pid, kernel_debugregs);
	write_debugregs(pid, TASK_DEBUGREGS(task));
}

#ifdef UML_CONFIG_PT_PROXY
/* Accessed only by the tracing thread */
static int debugregs_seq;

/* Only called by the ptrace proxy */
void ptrace_pokeuser(unsigned long addr, unsigned long data)
{
	if((addr < offsetof(struct user, u_debugreg[0])) ||
	   (addr > offsetof(struct user, u_debugreg[7])))
		return;
	addr -= offsetof(struct user, u_debugreg[0]);
	addr = addr >> 2;
	if(kernel_debugregs[addr] == data) return;

	kernel_debugregs[addr] = data;
	debugregs_seq++;
}

static void update_debugregs_cb(void *arg)
{
	int pid = *((int *) arg);

	write_debugregs(pid, kernel_debugregs);
}

/* Optimized out in its header when not defined */
void update_debugregs(int seq)
{
	int me;

	if(seq == debugregs_seq) return;

	me = os_getpid();
	initial_thread_cb(update_debugregs_cb, &me);
}
#endif

/*
 * Overrides for Emacs so that we follow Linus's tabbing style.
 * Emacs will notice this stuff at the end of the file and automatically
 * adjust the settings for this buffer only.  This must remain at the end
 * of the file.
 * ---------------------------------------------------------------------------
 * Local variables:
 * c-file-style: "linux"
 * End:
 */