aboutsummaryrefslogtreecommitdiff
path: root/arch/sh/kernel/ptrace_32.c
blob: 84bf3420597c77c861a1af55721e9c349b12e23b (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
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
/*
 * linux/arch/sh/kernel/ptrace.c
 *
 * Original x86 implementation:
 *	By Ross Biro 1/23/92
 *	edited by Linus Torvalds
 *
 * SuperH version:   Copyright (C) 1999, 2000  Kaz Kojima & Niibe Yutaka
 * Audit support: Yuichi Nakamura <ynakam@hitachisoft.jp>
 */
#include <linux/kernel.h>
#include <linux/sched.h>
#include <linux/mm.h>
#include <linux/smp.h>
#include <linux/errno.h>
#include <linux/ptrace.h>
#include <linux/user.h>
#include <linux/slab.h>
#include <linux/security.h>
#include <linux/signal.h>
#include <linux/io.h>
#include <linux/audit.h>
#include <linux/seccomp.h>
#include <linux/tracehook.h>
#include <asm/uaccess.h>
#include <asm/pgtable.h>
#include <asm/system.h>
#include <asm/processor.h>
#include <asm/mmu_context.h>
#include <asm/syscalls.h>

/*
 * does not yet catch signals sent when the child dies.
 * in exit.c or in signal.c.
 */

/*
 * This routine will get a word off of the process kernel stack.
 */
static inline int get_stack_long(struct task_struct *task, int offset)
{
	unsigned char *stack;

	stack = (unsigned char *)task_pt_regs(task);
	stack += offset;
	return (*((int *)stack));
}

/*
 * This routine will put a word on the process kernel stack.
 */
static inline int put_stack_long(struct task_struct *task, int offset,
				 unsigned long data)
{
	unsigned char *stack;

	stack = (unsigned char *)task_pt_regs(task);
	stack += offset;
	*(unsigned long *) stack = data;
	return 0;
}

void user_enable_single_step(struct task_struct *child)
{
	struct pt_regs *regs = task_pt_regs(child);
	long pc;

	pc = get_stack_long(child, (long)&regs->pc);

	/* Next scheduling will set up UBC */
	if (child->thread.ubc_pc == 0)
		ubc_usercnt += 1;

	child->thread.ubc_pc = pc;

	set_tsk_thread_flag(child, TIF_SINGLESTEP);
}

void user_disable_single_step(struct task_struct *child)
{
	clear_tsk_thread_flag(child, TIF_SINGLESTEP);

	/*
	 * Ensure the UBC is not programmed at the next context switch.
	 *
	 * Normally this is not needed but there are sequences such as
	 * singlestep, signal delivery, and continue that leave the
	 * ubc_pc non-zero leading to spurious SIGTRAPs.
	 */
	if (child->thread.ubc_pc != 0) {
		ubc_usercnt -= 1;
		child->thread.ubc_pc = 0;
	}
}

/*
 * Called by kernel/ptrace.c when detaching..
 *
 * Make sure single step bits etc are not set.
 */
void ptrace_disable(struct task_struct *child)
{
	user_disable_single_step(child);
}

long arch_ptrace(struct task_struct *child, long request, long addr, long data)
{
	struct user * dummy = NULL;
	unsigned long __user *datap = (unsigned long __user *)data;
	int ret;

	switch (request) {
	/* read the word at location addr in the USER area. */
	case PTRACE_PEEKUSR: {
		unsigned long tmp;

		ret = -EIO;
		if ((addr & 3) || addr < 0 ||
		    addr > sizeof(struct user) - 3)
			break;

		if (addr < sizeof(struct pt_regs))
			tmp = get_stack_long(child, addr);
		else if (addr >= (long) &dummy->fpu &&
			 addr < (long) &dummy->u_fpvalid) {
			if (!tsk_used_math(child)) {
				if (addr == (long)&dummy->fpu.fpscr)
					tmp = FPSCR_INIT;
				else
					tmp = 0;
			} else
				tmp = ((long *)&child->thread.fpu)
					[(addr - (long)&dummy->fpu) >> 2];
		} else if (addr == (long) &dummy->u_fpvalid)
			tmp = !!tsk_used_math(child);
		else
			tmp = 0;
		ret = put_user(tmp, datap);
		break;
	}

	case PTRACE_POKEUSR: /* write the word at location addr in the USER area */
		ret = -EIO;
		if ((addr & 3) || addr < 0 ||
		    addr > sizeof(struct user) - 3)
			break;

		if (addr < sizeof(struct pt_regs))
			ret = put_stack_long(child, addr, data);
		else if (addr >= (long) &dummy->fpu &&
			 addr < (long) &dummy->u_fpvalid) {
			set_stopped_child_used_math(child);
			((long *)&child->thread.fpu)
				[(addr - (long)&dummy->fpu) >> 2] = data;
			ret = 0;
		} else if (addr == (long) &dummy->u_fpvalid) {
			conditional_stopped_child_used_math(data, child);
			ret = 0;
		}
		break;

#ifdef CONFIG_SH_DSP
	case PTRACE_GETDSPREGS: {
		unsigned long dp;

		ret = -EIO;
		dp = ((unsigned long) child) + THREAD_SIZE -
			 sizeof(struct pt_dspregs);
		if (*((int *) (dp - 4)) == SR_FD) {
			copy_to_user((void *)addr, (void *) dp,
				sizeof(struct pt_dspregs));
			ret = 0;
		}
		break;
	}

	case PTRACE_SETDSPREGS: {
		unsigned long dp;

		ret = -EIO;
		dp = ((unsigned long) child) + THREAD_SIZE -
			 sizeof(struct pt_dspregs);
		if (*((int *) (dp - 4)) == SR_FD) {
			copy_from_user((void *) dp, (void *)addr,
				sizeof(struct pt_dspregs));
			ret = 0;
		}
		break;
	}
#endif
#ifdef CONFIG_BINFMT_ELF_FDPIC
	case PTRACE_GETFDPIC: {
		unsigned long tmp = 0;

		switch (addr) {
		case PTRACE_GETFDPIC_EXEC:
			tmp = child->mm->context.exec_fdpic_loadmap;
			break;
		case PTRACE_GETFDPIC_INTERP:
			tmp = child->mm->context.interp_fdpic_loadmap;
			break;
		default:
			break;
		}

		ret = 0;
		if (put_user(tmp, datap)) {
			ret = -EFAULT;
			break;
		}
		break;
	}
#endif
	default:
		ret = ptrace_request(child, request, addr, data);
		break;
	}

	return ret;
}

static inline int audit_arch(void)
{
	int arch = EM_SH;

#ifdef CONFIG_CPU_LITTLE_ENDIAN
	arch |= __AUDIT_ARCH_LE;
#endif

	return arch;
}

asmlinkage long do_syscall_trace_enter(struct pt_regs *regs)
{
	long ret = 0;

	secure_computing(regs->regs[0]);

	if (test_thread_flag(TIF_SYSCALL_TRACE) &&
	    tracehook_report_syscall_entry(regs))
		/*
		 * Tracing decided this syscall should not happen.
		 * We'll return a bogus call number to get an ENOSYS
		 * error, but leave the original number in regs->regs[0].
		 */
		ret = -1L;

	if (unlikely(current->audit_context))
		audit_syscall_entry(audit_arch(), regs->regs[3],
				    regs->regs[4], regs->regs[5],
				    regs->regs[6], regs->regs[7]);

	return ret ?: regs->regs[0];
}

asmlinkage void do_syscall_trace_leave(struct pt_regs *regs)
{
	int step;

	if (unlikely(current->audit_context))
		audit_syscall_exit(AUDITSC_RESULT(regs->regs[0]),
				   regs->regs[0]);

	step = test_thread_flag(TIF_SINGLESTEP);
	if (step || test_thread_flag(TIF_SYSCALL_TRACE))
		tracehook_report_syscall_exit(regs, step);
}