1 /*
2 * Copyright 2010 Tilera Corporation. All Rights Reserved.
3 *
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License
6 * as published by the Free Software Foundation, version 2.
7 *
8 * This program is distributed in the hope that it will be useful, but
9 * WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
11 * NON INFRINGEMENT. See the GNU General Public License for
12 * more details.
13 *
14 * Copied from i386: Ross Biro 1/23/92
15 */
16
17 #include <linux/kernel.h>
18 #include <linux/ptrace.h>
19 #include <linux/kprobes.h>
20 #include <linux/compat.h>
21 #include <linux/uaccess.h>
22 #include <asm/traps.h>
23
user_enable_single_step(struct task_struct * child)24 void user_enable_single_step(struct task_struct *child)
25 {
26 set_tsk_thread_flag(child, TIF_SINGLESTEP);
27 }
28
user_disable_single_step(struct task_struct * child)29 void user_disable_single_step(struct task_struct *child)
30 {
31 clear_tsk_thread_flag(child, TIF_SINGLESTEP);
32 }
33
34 /*
35 * Called by kernel/ptrace.c when detaching..
36 */
ptrace_disable(struct task_struct * child)37 void ptrace_disable(struct task_struct *child)
38 {
39 clear_tsk_thread_flag(child, TIF_SINGLESTEP);
40
41 /*
42 * These two are currently unused, but will be set by arch_ptrace()
43 * and used in the syscall assembly when we do support them.
44 */
45 clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
46 }
47
arch_ptrace(struct task_struct * child,long request,unsigned long addr,unsigned long data)48 long arch_ptrace(struct task_struct *child, long request,
49 unsigned long addr, unsigned long data)
50 {
51 unsigned long __user *datap = (long __user __force *)data;
52 unsigned long tmp;
53 long ret = -EIO;
54 char *childreg;
55 struct pt_regs copyregs;
56 int ex1_offset;
57
58 switch (request) {
59
60 case PTRACE_PEEKUSR: /* Read register from pt_regs. */
61 if (addr >= PTREGS_SIZE)
62 break;
63 childreg = (char *)task_pt_regs(child) + addr;
64 #ifdef CONFIG_COMPAT
65 if (is_compat_task()) {
66 if (addr & (sizeof(compat_long_t)-1))
67 break;
68 ret = put_user(*(compat_long_t *)childreg,
69 (compat_long_t __user *)datap);
70 } else
71 #endif
72 {
73 if (addr & (sizeof(long)-1))
74 break;
75 ret = put_user(*(long *)childreg, datap);
76 }
77 break;
78
79 case PTRACE_POKEUSR: /* Write register in pt_regs. */
80 if (addr >= PTREGS_SIZE)
81 break;
82 childreg = (char *)task_pt_regs(child) + addr;
83
84 /* Guard against overwrites of the privilege level. */
85 ex1_offset = PTREGS_OFFSET_EX1;
86 #if defined(CONFIG_COMPAT) && defined(__BIG_ENDIAN)
87 if (is_compat_task()) /* point at low word */
88 ex1_offset += sizeof(compat_long_t);
89 #endif
90 if (addr == ex1_offset)
91 data = PL_ICS_EX1(USER_PL, EX1_ICS(data));
92
93 #ifdef CONFIG_COMPAT
94 if (is_compat_task()) {
95 if (addr & (sizeof(compat_long_t)-1))
96 break;
97 *(compat_long_t *)childreg = data;
98 } else
99 #endif
100 {
101 if (addr & (sizeof(long)-1))
102 break;
103 *(long *)childreg = data;
104 }
105 ret = 0;
106 break;
107
108 case PTRACE_GETREGS: /* Get all registers from the child. */
109 if (copy_to_user(datap, task_pt_regs(child),
110 sizeof(struct pt_regs)) == 0) {
111 ret = 0;
112 }
113 break;
114
115 case PTRACE_SETREGS: /* Set all registers in the child. */
116 if (copy_from_user(©regs, datap,
117 sizeof(struct pt_regs)) == 0) {
118 copyregs.ex1 =
119 PL_ICS_EX1(USER_PL, EX1_ICS(copyregs.ex1));
120 *task_pt_regs(child) = copyregs;
121 ret = 0;
122 }
123 break;
124
125 case PTRACE_GETFPREGS: /* Get the child FPU state. */
126 case PTRACE_SETFPREGS: /* Set the child FPU state. */
127 break;
128
129 case PTRACE_SETOPTIONS:
130 /* Support TILE-specific ptrace options. */
131 child->ptrace &= ~PT_TRACE_MASK_TILE;
132 tmp = data & PTRACE_O_MASK_TILE;
133 data &= ~PTRACE_O_MASK_TILE;
134 ret = ptrace_request(child, request, addr, data);
135 if (tmp & PTRACE_O_TRACEMIGRATE)
136 child->ptrace |= PT_TRACE_MIGRATE;
137 break;
138
139 default:
140 #ifdef CONFIG_COMPAT
141 if (task_thread_info(current)->status & TS_COMPAT) {
142 ret = compat_ptrace_request(child, request,
143 addr, data);
144 break;
145 }
146 #endif
147 ret = ptrace_request(child, request, addr, data);
148 break;
149 }
150
151 return ret;
152 }
153
154 #ifdef CONFIG_COMPAT
155 /* Not used; we handle compat issues in arch_ptrace() directly. */
compat_arch_ptrace(struct task_struct * child,compat_long_t request,compat_ulong_t addr,compat_ulong_t data)156 long compat_arch_ptrace(struct task_struct *child, compat_long_t request,
157 compat_ulong_t addr, compat_ulong_t data)
158 {
159 BUG();
160 }
161 #endif
162
do_syscall_trace(void)163 void do_syscall_trace(void)
164 {
165 if (!test_thread_flag(TIF_SYSCALL_TRACE))
166 return;
167
168 if (!(current->ptrace & PT_PTRACED))
169 return;
170
171 /*
172 * The 0x80 provides a way for the tracing parent to distinguish
173 * between a syscall stop and SIGTRAP delivery
174 */
175 ptrace_notify(SIGTRAP|((current->ptrace & PT_TRACESYSGOOD) ? 0x80 : 0));
176
177 /*
178 * this isn't the same as continuing with a signal, but it will do
179 * for normal use. strace only continues with a signal if the
180 * stopping signal is not SIGTRAP. -brl
181 */
182 if (current->exit_code) {
183 send_sig(current->exit_code, current, 1);
184 current->exit_code = 0;
185 }
186 }
187
send_sigtrap(struct task_struct * tsk,struct pt_regs * regs,int error_code)188 void send_sigtrap(struct task_struct *tsk, struct pt_regs *regs, int error_code)
189 {
190 struct siginfo info;
191
192 memset(&info, 0, sizeof(info));
193 info.si_signo = SIGTRAP;
194 info.si_code = TRAP_BRKPT;
195 info.si_addr = (void __user *) regs->pc;
196
197 /* Send us the fakey SIGTRAP */
198 force_sig_info(SIGTRAP, &info, tsk);
199 }
200
201 /* Handle synthetic interrupt delivered only by the simulator. */
do_breakpoint(struct pt_regs * regs,int fault_num)202 void __kprobes do_breakpoint(struct pt_regs* regs, int fault_num)
203 {
204 send_sigtrap(current, regs, fault_num);
205 }
206