afabad230dbb4f212d057449f03f3fec3b79d171
[linux-2.6.git] / include / asm-powerpc / kprobes.h
1 #ifndef _ASM_POWERPC_KPROBES_H
2 #define _ASM_POWERPC_KPROBES_H
3 #ifdef __KERNEL__
4 /*
5  *  Kernel Probes (KProbes)
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License as published by
9  * the Free Software Foundation; either version 2 of the License, or
10  * (at your option) any later version.
11  *
12  * This program is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
15  * GNU General Public License for more details.
16  *
17  * You should have received a copy of the GNU General Public License
18  * along with this program; if not, write to the Free Software
19  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
20  *
21  * Copyright (C) IBM Corporation, 2002, 2004
22  *
23  * 2002-Oct     Created by Vamsi Krishna S <vamsi_krishna@in.ibm.com> Kernel
24  *              Probes initial implementation ( includes suggestions from
25  *              Rusty Russell).
26  * 2004-Nov     Modified for PPC64 by Ananth N Mavinakayanahalli
27  *              <ananth@in.ibm.com>
28  */
29 #include <linux/types.h>
30 #include <linux/ptrace.h>
31 #include <linux/percpu.h>
32
33 #define  __ARCH_WANT_KPROBES_INSN_SLOT
34
35 struct pt_regs;
36 struct kprobe;
37
38 typedef unsigned int kprobe_opcode_t;
39 #define BREAKPOINT_INSTRUCTION  0x7fe00008      /* trap */
40 #define MAX_INSN_SIZE 1
41
42 #define IS_TW(instr)            (((instr) & 0xfc0007fe) == 0x7c000008)
43 #define IS_TD(instr)            (((instr) & 0xfc0007fe) == 0x7c000088)
44 #define IS_TDI(instr)           (((instr) & 0xfc000000) == 0x08000000)
45 #define IS_TWI(instr)           (((instr) & 0xfc000000) == 0x0c000000)
46
47 #ifdef CONFIG_PPC64
48 /*
49  * 64bit powerpc uses function descriptors.
50  * Handle cases where:
51  *              - User passes a <.symbol> or <module:.symbol>
52  *              - User passes a <symbol> or <module:symbol>
53  *              - User passes a non-existant symbol, kallsyms_lookup_name
54  *                returns 0. Don't deref the NULL pointer in that case
55  */
56 #define kprobe_lookup_name(name, addr)                                  \
57 {                                                                       \
58         addr = (kprobe_opcode_t *)kallsyms_lookup_name(name);           \
59         if (addr) {                                                     \
60                 char *colon;                                            \
61                 if ((colon = strchr(name, ':')) != NULL) {              \
62                         colon++;                                        \
63                         if (*colon != '\0' && *colon != '.')            \
64                                 addr = *(kprobe_opcode_t **)addr;       \
65                 } else if (name[0] != '.')                              \
66                         addr = *(kprobe_opcode_t **)addr;               \
67         } else {                                                        \
68                 char dot_name[KSYM_NAME_LEN];                           \
69                 dot_name[0] = '.';                                      \
70                 dot_name[1] = '\0';                                     \
71                 strncat(dot_name, name, KSYM_NAME_LEN - 2);             \
72                 addr = (kprobe_opcode_t *)kallsyms_lookup_name(dot_name); \
73         }                                                               \
74 }
75
76 #define is_trap(instr)  (IS_TW(instr) || IS_TD(instr) || \
77                         IS_TWI(instr) || IS_TDI(instr))
78 #else
79 /* Use stock kprobe_lookup_name since ppc32 doesn't use function descriptors */
80 #define is_trap(instr)  (IS_TW(instr) || IS_TWI(instr))
81 #endif
82
83 #define ARCH_SUPPORTS_KRETPROBES
84 #define flush_insn_slot(p)      do { } while (0)
85 #define kretprobe_blacklist_size 0
86
87 void kretprobe_trampoline(void);
88 extern void arch_remove_kprobe(struct kprobe *p);
89
90 /* Architecture specific copy of original instruction */
91 struct arch_specific_insn {
92         /* copy of original instruction */
93         kprobe_opcode_t *insn;
94         /*
95          * Set in kprobes code, initially to 0. If the instruction can be
96          * eumulated, this is set to 1, if not, to -1.
97          */
98         int boostable;
99 };
100
101 struct prev_kprobe {
102         struct kprobe *kp;
103         unsigned long status;
104         unsigned long saved_msr;
105 };
106
107 /* per-cpu kprobe control block */
108 struct kprobe_ctlblk {
109         unsigned long kprobe_status;
110         unsigned long kprobe_saved_msr;
111         struct pt_regs jprobe_saved_regs;
112         struct prev_kprobe prev_kprobe;
113 };
114
115 extern int kprobe_exceptions_notify(struct notifier_block *self,
116                                         unsigned long val, void *data);
117 extern int kprobe_fault_handler(struct pt_regs *regs, int trapnr);
118 #endif /* __KERNEL__ */
119 #endif  /* _ASM_POWERPC_KPROBES_H */