ia64/linux-2.6.18-xen.hg

view arch/v850/kernel/ptrace.c @ 854:950b9eb27661

usbback: fix urb interval value for interrupt urbs.

Signed-off-by: Noboru Iwamatsu <n_iwamatsu@jp.fujitsu.com>
author Keir Fraser <keir.fraser@citrix.com>
date Mon Apr 06 13:51:20 2009 +0100 (2009-04-06)
parents 831230e53067
children
line source
1 /*
2 * arch/v850/kernel/ptrace.c -- `ptrace' system call
3 *
4 * Copyright (C) 2002,03,04 NEC Electronics Corporation
5 * Copyright (C) 2002,03,04 Miles Bader <miles@gnu.org>
6 *
7 * Derived from arch/mips/kernel/ptrace.c:
8 *
9 * Copyright (C) 1992 Ross Biro
10 * Copyright (C) Linus Torvalds
11 * Copyright (C) 1994, 95, 96, 97, 98, 2000 Ralf Baechle
12 * Copyright (C) 1996 David S. Miller
13 * Kevin D. Kissell, kevink@mips.com and Carsten Langgaard, carstenl@mips.com
14 * Copyright (C) 1999 MIPS Technologies, Inc.
15 *
16 * This file is subject to the terms and conditions of the GNU General
17 * Public License. See the file COPYING in the main directory of this
18 * archive for more details.
19 */
21 #include <linux/kernel.h>
22 #include <linux/mm.h>
23 #include <linux/sched.h>
24 #include <linux/smp_lock.h>
25 #include <linux/ptrace.h>
26 #include <linux/signal.h>
28 #include <asm/errno.h>
29 #include <asm/ptrace.h>
30 #include <asm/processor.h>
31 #include <asm/uaccess.h>
33 /* Returns the address where the register at REG_OFFS in P is stashed away. */
34 static v850_reg_t *reg_save_addr (unsigned reg_offs, struct task_struct *t)
35 {
36 struct pt_regs *regs;
38 /* Three basic cases:
40 (1) A register normally saved before calling the scheduler, is
41 available in the kernel entry pt_regs structure at the top
42 of the kernel stack. The kernel trap/irq exit path takes
43 care to save/restore almost all registers for ptrace'd
44 processes.
46 (2) A call-clobbered register, where the process P entered the
47 kernel via [syscall] trap, is not stored anywhere; that's
48 OK, because such registers are not expected to be preserved
49 when the trap returns anyway (so we don't actually bother to
50 test for this case).
52 (3) A few registers not used at all by the kernel, and so
53 normally never saved except by context-switches, are in the
54 context switch state. */
56 if (reg_offs == PT_CTPC || reg_offs == PT_CTPSW || reg_offs == PT_CTBP)
57 /* Register saved during context switch. */
58 regs = thread_saved_regs (t);
59 else
60 /* Register saved during kernel entry (or not available). */
61 regs = task_pt_regs (t);
63 return (v850_reg_t *)((char *)regs + reg_offs);
64 }
66 /* Set the bits SET and clear the bits CLEAR in the v850e DIR
67 (`debug information register'). Returns the new value of DIR. */
68 static inline v850_reg_t set_dir (v850_reg_t set, v850_reg_t clear)
69 {
70 register v850_reg_t rval asm ("r10");
71 register v850_reg_t arg0 asm ("r6") = set;
72 register v850_reg_t arg1 asm ("r7") = clear;
74 /* The dbtrap handler has exactly this functionality when called
75 from kernel mode. 0xf840 is a `dbtrap' insn. */
76 asm (".short 0xf840" : "=r" (rval) : "r" (arg0), "r" (arg1));
78 return rval;
79 }
81 /* Makes sure hardware single-stepping is (globally) enabled.
82 Returns true if successful. */
83 static inline int enable_single_stepping (void)
84 {
85 static int enabled = 0; /* Remember whether we already did it. */
86 if (! enabled) {
87 /* Turn on the SE (`single-step enable') bit, 0x100, in the
88 DIR (`debug information register'). This may fail if a
89 processor doesn't support it or something. We also try
90 to clear bit 0x40 (`INI'), which is necessary to use the
91 debug stuff on the v850e2; on the v850e, clearing 0x40
92 shouldn't cause any problem. */
93 v850_reg_t dir = set_dir (0x100, 0x40);
94 /* Make sure it really got set. */
95 if (dir & 0x100)
96 enabled = 1;
97 }
98 return enabled;
99 }
101 /* Try to set CHILD's single-step flag to VAL. Returns true if successful. */
102 static int set_single_step (struct task_struct *t, int val)
103 {
104 v850_reg_t *psw_addr = reg_save_addr(PT_PSW, t);
105 if (val) {
106 /* Make sure single-stepping is enabled. */
107 if (! enable_single_stepping ())
108 return 0;
109 /* Set T's single-step flag. */
110 *psw_addr |= 0x800;
111 } else
112 *psw_addr &= ~0x800;
113 return 1;
114 }
116 long arch_ptrace(struct task_struct *child, long request, long addr, long data)
117 {
118 int rval;
120 switch (request) {
121 unsigned long val, copied;
123 case PTRACE_PEEKTEXT: /* read word at location addr. */
124 case PTRACE_PEEKDATA:
125 copied = access_process_vm(child, addr, &val, sizeof(val), 0);
126 rval = -EIO;
127 if (copied != sizeof(val))
128 break;
129 rval = put_user(val, (unsigned long *)data);
130 goto out;
132 case PTRACE_POKETEXT: /* write the word at location addr. */
133 case PTRACE_POKEDATA:
134 rval = 0;
135 if (access_process_vm(child, addr, &data, sizeof(data), 1)
136 == sizeof(data))
137 break;
138 rval = -EIO;
139 goto out;
141 /* Read/write the word at location ADDR in the registers. */
142 case PTRACE_PEEKUSR:
143 case PTRACE_POKEUSR:
144 rval = 0;
145 if (addr >= PT_SIZE && request == PTRACE_PEEKUSR) {
146 /* Special requests that don't actually correspond
147 to offsets in struct pt_regs. */
148 if (addr == PT_TEXT_ADDR)
149 val = child->mm->start_code;
150 else if (addr == PT_DATA_ADDR)
151 val = child->mm->start_data;
152 else if (addr == PT_TEXT_LEN)
153 val = child->mm->end_code
154 - child->mm->start_code;
155 else
156 rval = -EIO;
157 } else if (addr >= 0 && addr < PT_SIZE && (addr & 0x3) == 0) {
158 v850_reg_t *reg_addr = reg_save_addr(addr, child);
159 if (request == PTRACE_PEEKUSR)
160 val = *reg_addr;
161 else
162 *reg_addr = data;
163 } else
164 rval = -EIO;
166 if (rval == 0 && request == PTRACE_PEEKUSR)
167 rval = put_user (val, (unsigned long *)data);
168 goto out;
170 /* Continue and stop at next (return from) syscall */
171 case PTRACE_SYSCALL:
172 /* Restart after a signal. */
173 case PTRACE_CONT:
174 /* Execute a single instruction. */
175 case PTRACE_SINGLESTEP:
176 rval = -EIO;
177 if (!valid_signal(data))
178 break;
180 /* Turn CHILD's single-step flag on or off. */
181 if (! set_single_step (child, request == PTRACE_SINGLESTEP))
182 break;
184 if (request == PTRACE_SYSCALL)
185 set_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
186 else
187 clear_tsk_thread_flag(child, TIF_SYSCALL_TRACE);
189 child->exit_code = data;
190 wake_up_process(child);
191 rval = 0;
192 break;
194 /*
195 * make the child exit. Best I can do is send it a sigkill.
196 * perhaps it should be put in the status that it wants to
197 * exit.
198 */
199 case PTRACE_KILL:
200 rval = 0;
201 if (child->exit_state == EXIT_ZOMBIE) /* already dead */
202 break;
203 child->exit_code = SIGKILL;
204 wake_up_process(child);
205 break;
207 case PTRACE_DETACH: /* detach a process that was attached. */
208 set_single_step (child, 0); /* Clear single-step flag */
209 rval = ptrace_detach(child, data);
210 break;
212 default:
213 rval = -EIO;
214 goto out;
215 }
216 out:
217 return rval;
218 }
220 asmlinkage void syscall_trace(void)
221 {
222 if (!test_thread_flag(TIF_SYSCALL_TRACE))
223 return;
224 if (!(current->ptrace & PT_PTRACED))
225 return;
226 /* The 0x80 provides a way for the tracing parent to distinguish
227 between a syscall stop and SIGTRAP delivery */
228 ptrace_notify(SIGTRAP | ((current->ptrace & PT_TRACESYSGOOD)
229 ? 0x80 : 0));
230 /*
231 * this isn't the same as continuing with a signal, but it will do
232 * for normal use. strace only continues with a signal if the
233 * stopping signal is not SIGTRAP. -brl
234 */
235 if (current->exit_code) {
236 send_sig(current->exit_code, current, 1);
237 current->exit_code = 0;
238 }
239 }
241 void ptrace_disable (struct task_struct *child)
242 {
243 /* nothing to do */
244 }